description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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RELATED APPLICATION
[0001] The current application claims the benefit of co-pending U.S. Provisional Application No. 60/485,214, filed on Jul. 7, 2003, which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to furniture and three-dimensional art (“structures”), and more particularly to a method of making these structures.
[0004] 2. Related Art
[0005] Conventionally, furniture and three-dimensional art (“structures”) are manufactured using various combinations of well known materials (e.g., wood, polished glass, metal, etc.) that are assembled using well known construction techniques. While these materials and techniques provide a traditional look and/or feel for the resulting structure, many individuals desire structures having a more unique look and/or feel. One way to obtain a unique look and/or texture for a structure is through the use of other nontraditional material. Thus, a need exists for a new method of manufacturing that allows various materials to be used in the creation of a structure to create a unique look and/or a unique texture for the structure.
SUMMARY OF THE INVENTION
[0006] The invention provides a method of making structures wherein the materials used and looks achieved can vary widely from the conventional methods and looks. In particular, a mold can be created to create an element of the structure having a desired shape. Resin and/or other materials can be poured into the mold and allowed to harden. Subsequently, the element can be combined with one or more additional elements to form the structure. In one embodiment, an interior of the mold is lined with a sheet that allows the element to be readily removed and easy reuse of the mold for a subsequent element. Further, a release agent can be applied to the sheet and/or mold to further assist in removing the element. As a result, the invention provides a solution for making a non-traditional structure that has a unique look in a manner that allows a shape of one or more elements of the structure to be reused for other elements for the same or numerous structures.
[0007] A first aspect of the invention comprises a method of constructing an element of a structure, the method comprising: creating a mold having a desired shape of the element; lining an interior of the mold with a sheet; and pouring resin into the mold to create the element.
[0008] A second aspect of the invention comprises a method of constructing a structure, the method comprising: creating a mold having a desired shape of at least one element of the structure; lining an interior of the mold with a sheet; applying a release agent to the sheet; pouring resin into the mold to create the at least one element; and removing the at least one element from the mold after the resin has hardened.
[0009] A third aspect of the invention comprises a structure comprising at least one structural support element comprising resin and at least one solid deposited therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which:
[0011] FIG. 1 shows an illustrative mold for creating an element of a structure;
[0012] FIG. 2 shows an illustrative table;
[0013] FIG. 3 shows an illustrative clock; and
[0014] FIG. 4 shows illustrative method steps for creating an element of a structure.
[0015] It is noted that the drawings of the invention are not to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As described above, the invention provides a method of making structures wherein the materials used and looks achieved can vary widely from the conventional methods and looks. In particular, a mold can be created to create an element of the structure having a desired shape. Resin and/or other materials can be poured into the mold and allowed to harden. Subsequently, the element can be combined with one or more additional elements to form the structure. In one embodiment, an interior of the mold is lined with a sheet that allows the element to be readily removed and easy reuse of the mold for a subsequent element. Further, a release agent can be applied to the sheet and/or mold to further assist in removing the element. As a result, the invention provides a solution for making a non-traditional structure that has a unique look in a manner that allows a shape of one or more elements of the structure to be reused for other elements for the same or numerous structures.
[0017] Turning to the Figures, FIG. 1 shows an illustrative mold 10 for creating an element of a structure according to one embodiment of the invention. As used herein, the term “structure” is used to refer to any three-dimensional work, including a sculpture, furniture such as a table, shelf, chair, etc., and accent furniture such as a clock, frame, light, etc. Further, the term “element” is used to refer to any part that forms the structure. For example, a table would typically include elements comprising four legs and a top.
[0018] In general, mold 10 can comprise any combination of various traditional manufacturing elements such as cardboard, wood, clay, plaster, tape, etc. Further, mold 10 can be created to form an element having any desired shape. To this extent, mold 10 can be used to form an element having a substantially longer length than width/depth (e.g., a leg for a table), an element having a small depth but relatively large width/length (e.g., a side for a mantel clock), etc. In the latter case, one side of the element can be uncovered by mold 10 . As will be discussed further below, this configuration can generate an element having one side with that is uniquely textured.
[0019] Additional details of FIG. 1 are discussed in conjunction with FIG. 4 , which shows illustrative method steps for creating an element using mold 10 . In step S 1 of FIG. 4 , mold 10 is created, which has a desired shape of the element to be constructed using mold 10 . In step S 2 , an interior of mold 10 can be lined with a sheet 12 . Sheet 12 can be used to ease in the removal of the element from mold 10 . To this extent, sheet 12 can comprise any type of flexible sheet that can substantially conform to the shape of the element (interior of mold 10 ). For example, sheet 12 can comprise a thin sheet of plastic (e.g., plastic wrap) or a thin flexible sheet of metal (e.g., aluminum foil).
[0020] In step S 3 , a release agent 14 can be applied to sheet 12 . Release agent 14 can assist in removing a finished element from mold 10 and sheet 12 . To this extent, it is understood that release agent 14 should be present on a side of sheet 12 facing toward the interior of mold 10 . In one embodiment, release agent 14 can be applied to sheet 12 prior to step S 2 , and sheet 12 is placed in the interior of mold 10 so that release agent 14 is appropriately located. Alternatively, release agent 14 can be applied directly to mold 10 . Further, release agent 14 could be used instead of sheet 12 . Still further, sheet 12 could be permanently or temporarily attached to mold 10 . In any event, release agent 14 can comprise any type of compound that will assist in removing the finished element from mold 10 and/or sheet 12 . For example, release agent 14 could comprise a mold release typically used in candle making.
[0021] In step S 4 , resin 16 is poured into mold 10 . Resin 16 can comprise any type of resin that comprises a liquid form when obtained, but will harden once exposed to air and/or heat. To this extent, resin is typically used as a general surface coating for a table top or the like. In one embodiment, resin 16 comprises a two-part epoxy resin substantially comprising of a resin and a hardener. Further, resin 16 can comprise a dye resin or the like. In any event, resin 16 is poured into mold 10 and allowed to harden to form the element. As a result, resin is used to create the element, rather than merely coating a surface of the element.
[0022] In step S 5 , one or more solids 18 can be deposited into mold 10 . Solid(s) 18 can be deposited after pouring resin 16 and prior to its hardening and/or prior to pouring resin 16 into mold 10 . In either case, resin 16 hardens around all or a portion of solids 18 to create the element. Each solid 18 can comprise any material, size and/or shape to obtain a desired appearance of the element. However, in one embodiment of the invention no solid 18 individually provides support and/or shape for the element without the hardened resin 16 . For example, solid(s) 18 can comprise broken glass, pottery, stone, plastic, sand, a mirror, wire, porcelain, etc. Further, solid(s) 18 can comprise plant and/or animal materials such as wood, leaves, fruit, vegetables, etc.
[0023] Once resin 16 has hardened, the element can be removed from mold 10 . For example, sheet 12 and resin 16 can be removed, and sheet 12 can be removed from resin 16 . As noted above, release agent 14 can further assist in the removal of the element so that mold 10 is not damaged and can be used to create another element. One or more additional steps also may be required. For example, due to the way resin 16 hardens, it may be necessary to remove excess resin from the element. In any event, the element can then be used to construct a structure that includes a plurality of elements.
[0024] FIGS. 2 and 3 show illustrative structures 120 , 220 , respectively. Structures 120 , 220 are formed by assembling elements 110 A-C, 210 to one or more additional elements. For example, as shown in FIG. 2 , elements 110 A-B can provide structural support for structure 120 . In this case, elements 110 A-B comprise legs for structure 120 . To this extent, it is understood that one or more traditional structural support elements can be included in elements 110 A-B to provide additional support for structure 120 . For example, one or more of elements 110 A-B could have a metallic rod or the like disposed within resin 16 ( FIG. 1 ) and along the length of element 11 A-B to provide support for structure 120 when disposed in an upright position. However, it is understood that element 110 A-B will comprise a large portion of resin 16 ( FIG. 1 ) and/or solids 18 ( FIG. 1 ) that substantially define the overall look and/or shape of element 110 A-B.
[0025] Structure 120 can also include one or more elements that comprise traditional building materials such as wood, marble, polished glass, and the like that are formed using traditional building techniques. For example, a top 122 and/or a lower support/shelf 124 of structure 120 can comprise glass. Further, other materials can be incorporated into structure 120 to add support. For example, top surface 122 could comprise a thermoplastic acrylic resin, a light weather resistant thermoplastic, a polycarbonate, or the like, alone or in combination with resin 16 ( FIG. 1 ). Still further, top 122 and shelf 124 could both comprise resin 16 and be constructed as described above. To this extent, structure 110 can comprise a plurality of resin 16 and/or solid 18 ( FIG. 1 ) elements joined to other resin 16 and/or solid 18 elements.
[0026] Additionally, a structure can include other functional elements. For example, structure 120 is shown including a drawer 126 . Drawer 126 comprises an element 110 C for a facing side of drawer 126 . In one embodiment, drawer 126 can comprise a bottom 128 and one or more sides 130 A-B comprising a smooth material such as a thermoplastic acrylic resin, a light weather resistant thermoplastic, a polycarbonate, polished glass, wood, etc. To construct element 110 C, mold 10 ( FIG. 1 ) can comprise a relatively narrow depth compared to the width and length. Further, a top of mold 10 can remain exposed. As a result, when one or more solids 18 ( FIG. 1 ) are used in element 110 C, portions of the solids 18 may protrude from the hardened resin 16 ( FIG. 1 ).
[0027] Further, other solids can be disposed in mold 10 to provide functionality desired for element 110 C. For example, a handle 132 can be placed in a desired position in element 110 C. Various other functional solids, such as mechanical elements, can be incorporated into an element. For example, FIG. 3 shows an illustrative structure 220 that comprises a clock 240 . Element 210 comprises a facing side of structure 220 and can comprise a structural support for structure 220 . Clock 240 can be placed in resin 16 ( FIG. 1 ) or be attached to element 210 after resin 16 has hardened using a traditional assembling technique as is known. It is understood that drawer 126 ( FIG. 2 ) and clock 240 are only illustrative. To this extent, structures 120 , 220 can include various other functional elements. For example, a door can be disposed on a back side of structure 220 to allow access to a back of clock 240 . In this case, hinges and the like can be used to attach the door to structure 220 . Further, felt or the like can be applied to the bottom of the structure to prevent scratching.
[0028] A top 242 and/or a bottom 244 of structure 220 can comprise elements made as described herein or made of traditional building material using a traditional manufacturing technique. In the former case, mold 10 ( FIG. 1 ) can comprise a shape that forms a groove or the like in order to assist in attaching the elements to form structure 220 . Alternatively, the required shape can be removed from and/or added to the element after resin 16 ( FIG. 1 ) has hardened. Still further, traditional attaching approaches such as nails, screws, glue, etc., can be used to attach the elements.
[0029] The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the invention as defined by the accompanying claims. | A method of manufacturing a structure by forming an element of the structure using a mold. Resin is poured into the mold to form the element. The element can further incorporate any number of a variety of solids. The element may then be assembled with one or more additional elements to complete the structure. | 0 |
BACKGROUND OF THE INVENTION
The present invention is directed to a wire guide element for a distributor unit in telecommunication systems that is composed of an oblong and essentially U-shaped carrier part for accepting plug connector strips for connecting and joining outgoing and incoming lines. This carrier part is in turn brought into a ready-to-use installation state on the basis of a retainer element firmly connectable thereto given longitudinally vertical alignment. An expansion is possible on the basis of at least one identical distributor unit to be attached laterally and line leads proceed between respectively two such neighboring distributor units. A separate cover hood can be put in place on each distributor unit.
Such a distributor unit serves the purpose of running patching wires from any arbitrary terminal point of the plug connector strips for incoming lines to any arbitrary terminal point of the plug connector strips for the outgoing lines leading for, example, to the switching equipment. In modern distributor systems a surveyable wiring arrangement must be provided even for increasing wiring density. In order to achieve such an ordered laying of lines, for example, hook-shaped or bow-shaped wire guide elements are arranged in the region of the wire guide waves that are provided. Given a correspondingly high number of subscribers, a distributor unit may also be expanded by identical distributor units to be arranged in immediate adjacency at both sides.
SUMMARY OF THE INVENTION
It is an object of the present invention to enable an optimum guidance of the lines to be laid between the distributor units on the basis of correspondingly matched and placed guide elements. This is achieved in that the wire guide element is fashioned as a plastic part and, for the purpose of forming a transverse channel between two immediately adjoining sub-units, represents a hollow member open at two opposite sides whose lower wall region has outwardly directed guide pegs with which it can be directly plugged onto the face edge of every leg of the carrier part open toward the front. A mechanical connection to the retainer element projecting beyond the carrier part in the longitudinal direction occurs by fastening elements attached to the back side.
The wire guide element can be cost-beneficially manufactured in plastic and can be secured in the face end region with adequate stability in a simple way. In addition to the space established by the hollow member, additional lines can be conducted at the wire guide element on the basis of pin-shaped or hook-shaped projections applied to the outside wall.
In accordance with the development of the present invention, a hook-like formed portion that continues in a finger-like, resilient tab is provided as fastening element at the back side. A cut-out is provided at the plate serving as retainer element, being provided in the region of each and every leg. For mechanical joining, the hook-like formed portion embraces the lower edge of the cut-out and the resilient tab snaps in under the upper edge of this cut-out.
The wire guide element placed on the face edge of the carrier part is thus held with adequate stability in an extremely simple way. The guide element is locked after the snap-in of the resilient tab. This locking is inventively promoted by a rib applied to the resilient end of the tab. According to a development of the present invention, the wire guide element that, after fastening, has its open sides directed in the direction of the distributor units neighboring one another has a slot pointing in this same direction at the wall surface accessible from the front.
As a result thereof, the conductors can be placed into the wire guide element in a simple way.
A particular ease of insertion results in that, given a rectangular cross section of the hollow member, the slot is provided in the region of the upper edge of the upper and front wall parts that abut one another.
The insertion of the lines is also additionally facilitated in that, for forming the slot, the upper part of the front wall surface points obliquely inward in the direction toward the upper side.
The development of the present invention is that the wire guide element has such an extent in the transverse direction defined by the open sides that it engages at least beyond the lateral limits respectively established by a cover hood and into the immediately adjoining distributor unit, whereby a cut-out matched to the dimensions of the wire guide element is provided in every side wall of the cover hood.
The line wires laid between the neighboring distributor units are thus protected against injury in the region of this covering in a simple way.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel, are set forth with particularity in the appended claims. The invention, together with further objects and advantages, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the several Figures in which like reference numerals identify like elements, and in which:
FIG. 1 is a perspective exploded view of a distributor unit;
FIGS. 2 and 3 are two views of the wire guide element;
FIG. 4 depicts an enlarged portion of the fastening element; and
FIG. 5 is a plan view of the front side of a distributor unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
According to FIG. 1, the basic unit provided, for example, for mounting at a wall is composed of the carrier part 1 and of the plate 3 connectable thereto in the upper and lower region. The carrier part is fashioned U-shaped and is manufactured as an extruded profile, whereby any desired length dimension is then respectively possible by simply cutting off from the extended material. On the basis of a corresponding design of the free edge of each and every leg of this U-form of the carrier part, the plug connector strip 6 or, respectively, 7 can be secured to these edges. To this end, for example, the free edge of the one leg can comprise a through, potentially slightly inwardly inclined completely cylindrical form. A plug connector strip that has its end face provided with a cut-out adapted thereto is then plugged onto this completely cylindrical form. The other leg comprises a through screw channel at the free edge. After the plug connector strip is plugged onto the fully cylindrically fashioned edge of the other leg, the respective plug connector strip is to be put in place onto the edges of the screw channel at any arbitrary location at the long side of the carrier part, for example with a flange attached in said plug connector strip. Given a corresponding perforation of the flange, the plug connector strip can be secured to the carrier part 1 in the screw channel with a self-taping screw. For forming a distributor block, the carrier part accepts (in the way just set forth) a plurality of plug connector strips 6 or, respectively, 7 that have their long sides following one another. For example, plug connector strips 7 wherein terminal elements are provided at the long sides lying opposite one another can be employed as plug connector strips 7. In accord therewith, for example, the terminal elements for the lines that lead to the switching equipment and that are seldom rearranged are arranged at the back side of the strip. These lines of the internal side outgoing as cable 8 can already be connected at the factory. They are connected to a plug device 9 for contacting to the cooperating contacts present in the switching equipment. The terminal elements for the external side, i.e. for the subscriber lines, continue to be provided at the front, servicing side of the strip. These terminal elements are thus easily accessible, so that alterations in the occupation of the strip can be undertaken without further ado. For the ordered guidance of the lines, bow-shaped or hook-shaped wire guide elements 10 are to be snapped in place in a simple way at the one leg of the U-shaped profile. A vertical channel for guiding the lines is thus available with these elements.
For fastening to the wall, the carrier part 1 has its upper and its lower end screwed to a plate 3 fashioned C-shaped. This plate projects beyond the carrier part 1 both in longitudinal direction as well as at one side. With such a plate, a defined spacing between the distributor block and a wall surface can be observed after installation. Cables are to be guided in this wall spacing region. On the basis of appropriate clips 4, the perforations present in the laterally projecting part of the plate 3 serve the purpose of fastening the cables laterally held by the wire guide elements 10. After, for example, being deflected from above into the space prescribed by the carrier part 1, the appertaining conductors are then conducted to the plug connector strip 7. The illustration of FIG. 1 also shows a rail-like element 5 that serves the purpose of fastening accessory equipment. In its normal position, it is hooked to the upper edge of the plate 3. After being completely equipped, a distributor unit can be provided with a cover hood 11. This cover hood 11 comprises recesses at both sides that are to be covered with inserted and locked plastic parts 12. These recesses serve the purpose of enabling transverse channels when a distributor unit is expanded by an identical distributor unit to be respectively arranged in immediate lateral proximity.
FIGS. 2 through 4 show details of the wire guide element 2 implacable onto the face edge of the carrier part 1. Lines are conducted through and the rectangular cavity surrounded by its walls 20 through 23 or, respectively, are introduced from the front through the slot 14 into the hollow member. For forming the slot 14 present at the upper front side, the free upper edge of the wall surface 20 is guided obliquely inward to the upper limiting surface. The edges of the part directed inward and in an arcuate angle at the middle, as may be derived from FIG. 3. The front wall part 20 is resiliently fashioned so that, in combination with the shape of the slot 14, the introduction of cables or, respectively, lines becomes unproblematical.
The guide pegs 13 on the under side of the wire guide element 2, as well as, the hook 17 arranged at the back side thereof in combination with the resilient tab 18 serve the purpose of attaching the wire guide element 2 to the face edge of a leg of the carrier part 1. In the exemplary embodiment, these fastening elements are applied to a web 15 that in turn departs from the back-side wall 22 of the hollow member. Dependent on the desired dimensioning of this hollow member, these fastening elements could also be secured directly to the back-side wall part 22.
The multiply provided guide pegs 13 are offset relative to one another in accord with the shaping of the leg of the carrier part. When the wire guide element 2 is put in place, these pegs embrace the upper edge of the profile. The hook 17 is introduced into the cut-out 24 that is provided in the plate 3. The wire guide element 2 is moved downward until the hook 17 embraces the lower edge of the cut-out 24. During this emplacement motion, the resilient tab 18 is first conducted along the corresponding wall of the plate 3, whereby it supports itself with a defined spring power. When the final position is reached, the resilient tab 18 snaps into the cut-out 24 at the upper edge of the cut-out 24 with its rib 19 applied to it. A locking is thus achieved, so that the wire guide element can only be removed after a simple, manual unlocking. The final position that has been assumed is thus secured by the said fastening elements in combination with the guide pegs 13.
The fastening elements composed of the hook 17 and the resilient tab 18 with which the fastening to the plate 3 is undertaken are again shown excerpted in FIG. 4 in an enlarged scale.
A hook-shaped formed portion 16 that has a defined spacing from the plate 3 is additionally provided at the upper side of the wire guide element 2. Cables or, respectively, conductors can likewise be guided in this space between the plate 3 and the hook-like shaped portion 16. This, for example, prevents such conductors from tilting over toward the front side.
The equipping of the distributor unit with the individual elements is indicated in the distributor unit shown without cover hood in FIG. 5. Proceeding from a prescribed marking line M, a field of plug connector strips 7 is present above this line and these, for example, are allocated to the internal side as separating or disconnect strips. The conductors 25 to be connected to these strips, consequently, lead to the switching equipment. As already mentioned, these lines are secured with, for example, spring clips 4 to the plate 3 that laterally extends beyond the profile of the carrier part 1. The insertion, contacting and fastening onto the plates 3 is provided away from the profile in order to avoid threading given a later expansion. Proceeding from the fastening location at the upper plate 3, the individual conductors are guided from above to the separating or disconnect strip 7 and are connected to the terminal elements thereof. These terminal elements are usually fashioned as clamp elements that allow a stripping-free connection of the electrical conductors. For example, the conductors leading to the switching equipment can be connected to the terminal elements provided a the under side of the separating or disconnect strip. The terminal elements present at the upper side thereof are then present for the variable connections to be occupied within the scope of what is referred to as jumpering. These are easily accessible from the front. Protective plugs 28 are to be plugged as needed onto the plug connector strip 7 allocated to the internal side.
Jumpering is then not undertaken directly with the conductors of the internal cable 26; rather, the conductors are clamped to terminal elements of the strapping connectors 6 arranged under the marking line M. The actual jumpering is then undertaken between the terminal elements of the separating or disconnect strips respectively present at the front side and the terminal elements of the strapping connectors. As a result of the division of the strip fields ensuing proceeding from a defined marking M, the expansion to be undertaken gradually, for example, in accord with the increase in the number of subscribers is facilitated when expansion is undertaken in downward or, respectively, in upward direction proceeding from this marking. The plug connector strips are independent of the wire guides and can be subsequently introduced.
The rail 5 equipped with accessory equipment 27 is hooked in above the carrier part 1 at the plate 3 screwed to the back side thereof. This rail 5 is shown broken so that the conductors normally covered by it are visible. The position 5a of this rail corresponds to the parking position that can be assembled by being simply plugged onto the edge of the plate 3.
In the exemplary embodiment of FIG. 4, further distributor units are provided at both sides at the distributor unit shown without cover hood. The wire guide elements 2 that, for example, are respectively put in place at the face edge of the leg immediately neighboring the adjoining distributor unit engage somewhat into the respectively other distributor unit. As a result thereof, the lines proceeding between the individual distributor units cannot be injured by the cut-out edges of the respective cover hoods 11.
The invention is not limited to the particular details of the apparatus depicted and other modifications and applications are contemplated. Certain other changes may be made in the above described apparatus without departing from the true spirit and scope of the invention herein involved. It is intended, therefore, that the subject matter in the above depiction shall be interpreted as illustrative and not in a limiting sense. | Wire guide element for a distributor unit in telecommunication systems. The plug connector strips of the distributor unit are secured to the edges of a vertically aligned U-shaped carrier part. A hollow plastic member is used as a wire guide element for the lines proceeding between neighboring distributor units arranged at both sides. With the guide peg present at the under side, this hollow plastic member is plugged, on the one end, onto the upper edge of the leg of the carrier part and, on the other hand, is snapped onto the retainer plate joined in this region to the carrier part at the back side. At least one hook attached to the upper side parallel to the plate also serves for the ordered guidance of lines. At its front side, the hollow member has a slot specifically designed for the insertion of lines. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to electromechanical assemblies of the type which include: a) an electrical component having a planar array of input/output pads, b) a substrate having a matching planar array of input/output pads, and c) respective solder joints that connect corresponding input/output pads of the electrical component and the substrate. More particularly, this invention relates to processes for stretching the solder joints in the above type of electromechanical assemblies in order to make the assemblies less susceptible to failure, due to the reduction of thermally induced stress and strain.
One specific example of the above type of assembly is where the electrical component is an integrated circuit die and the substrate is a cofired multi-layered ceramic substrate. To fabricate such an assembly, a respective "solder ball" is deposited on each of the input/output pads of the die. Typically, this is achieved by providing a mask which has an array of holes that only expose the die's input/output pads, and by vaporizing solder through the mask onto the input/output pads. Thereafter, the solder on the die is reflowed by a heating step, and then the die is placed on the substrate such that the die's solder balls are aligned with the substrate input/output pads. Then the solder balls are heated until they melt; and, lastly, the solder is cooled and resolidified to thereby form the solder joints between the aligned input/output pads.
During the above described prior art process, each of the solder joints is formed with a convex shape (i.e.--barrel shape). This shape occurs because when the solder balls are melted, the surface tension in each molten solder ball tends to minimize the solder ball's surface area; and for any given volume of molten solder, the minimum surface area is reached when the shape is spherical.
However, convex shaped solder joints have a major drawback when thermally induced stress and strain are considered. These stresses and strains arise when the die and the substrate are repeatedly heated and cooled during their operation. Due to that heating and cooling, the die and the substrate expand and contract; and if the die and the substrate have different thermal expansion coefficients, they will expand and contract by a different amount. In each solder joint, the average strain equals the difference by which the ends of the joint move divided by the height of the joint. Thus, as the joint shape bulges outward more, the joint height gets smaller for any given solder volume; and that decrease in joint height makes the strain larger. Likewise, the joint stress gets larger since it increases whenever strain increases.
A recent paper which discusses the above stress/strain problem is: "Mechanical Design Considerations For Area Array Solder Joints" by Peter Borgenson, Chi-Lu Li and H. D. Conway, IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Volume 16, No. 3, May 1993 at pages 272-283. In that paper, the conventional convex shaped solder joint is shown in FIG. 4 on page 275.
Following FIG. 4, the paper goes through a mathematical analysis which shows that the stress in a mathematically modeled solder joint can be reduced if the joint length is somehow increased until the shape of the joint changes from convex to concave. Then, to actually build a real concave shaped solder joint, the paper on page 277 says: "In principal, different solder joint shapes may be achieved by two types of means. For one, we may, for example, vary either solder volume or pad size. Alternatively, we may somehow apply an additional downward or upward force during reflow".
However, in the remainder of the paper, the only actual method which is disclosed for fabricating a concave shaped solder joint is where the solder volume is varied; and that method is described in conjunction with FIG. 18. According to that disclosed method, solder balls are deposited on the die interior with a large volume of solder, and solder balls are deposited on the die periphery with a small volume of solder. Since the interior solder balls have a large volume of solder, those interior solder balls push the die farther away from the substrate than the periphery solder balls. Consequently, the solder balls on the periphery of the die get stretched and thereby achieve a concave shape.
But one major drawback with the above described method is that as the amount of solder in each interior solder ball increases, those solder balls become so large that the small periphery solder balls do not contact the input/output pads on the substrate when all of the solder balls are melted. Consequently, an additional undisclosed step would be required to somehow squeeze the large interior solder balls while they are molten until each small periphery solder ball contacts and forms a joint with the substrate input/output pads. Also, while the large molten interior solder balls are squeezed, a second additional undisclosed step would be required to somehow insure that the die does not tip and thereby cause any molten solder ball to be squeezed so much that it "squirts" off of it's input/output pad. Further, after the small molten solder balls on the die periphery have contacted the substrate input/output pads, a third undisclosed additional step would be required wherein the squeezing force is somehow removed so the small periphery solder balls get stretched.
Another drawback of the above described process is that as the amount of solder in each interior solder ball is increased, the cross-sectional area of that solder ball must likewise be increased. That is because when the solder ball is initially deposited on the input/output pad by vaporizing solder through a mask, it is impossible to exceed a certain height-to-width aspect ratio for the solder ball. Consequently, if it is desired to double the height of the interior solder balls, then the radius of those solder balls must also be approximately doubled. However, doubling the radius of the internal solder balls means that their cross-sectional area will be increased approximately by a factor of four; and thus the density with which an array of those solder balls can be formed will be decreased by approximately a factor of four. This is a serious problem because it limits the number of input/output signals that can be sent to/received from a die of any given size.
Accordingly, a primary object of the invention is to provide an improved method of elongating the solder joints in an electromechanical assembly wherein the above problems are overcome.
BRIEF SUMMARY OF THE INVENTION
In one particular implementation of the present invention, the solder joints between the input/output pads of an integrated circuit die and corresponding input/output pads on a substrate are stretched by the steps of: a) melting the solder joints; b) surrounding the die with a fixture while the solder joints are melted such that the die can not rotate and can not move laterally, but can move substantially perpendicular to the substrate by just a predetermined distance; c) subjecting the die to a vacuum, while the die is confined by the fixture, such that the die moves inside the fixture by the predetermined distance and then hits the fixture and stops; and d) resolidifying the solder joints while the die is held by the vacuum against the fixture.
Alternatively, in a second implementation, the moving and stopping steps are achieved by a mechanical apparatus. This apparatus has a set of arms that grasp the die by its sides and then move the die perpendicular to the substrate by the predetermined distance. While the arms move, a fixture prevents rotational and lateral movement of the die.
With both of the above process implementations, the solder joints that are stretched can be disposed on the integrated circuit die in a high density array since none of the solder joints at the center of the array need to have a large volume. Also, both of the above process implementations use fewer steps than the Borgenson-Li-Conway variable solder process, and thus they are better suited for mass producing products at cost competitive prices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a fixture and an apparatus which are positioned on an electromechanical assembly and which operate to stretch solder joints in that assembly in accordance with the present invention.
FIG. 2 shows the electromechanical assembly of FIG. 1, together with the fixture and the bottom portion of the FIG. 1 apparatus, after the solder joints have been stretched.
FIG. 3 is a set of curves, generated by a computer analysis, which illustrate how the shape of each solder joint changes as it is stretched by the fixture and apparatus of FIGS. 1 and 2.
FIG. 4 is a computer generated curve which shows the amount of force that is applied to each solder joint in order to achieve the various solder joint shapes of FIG. 3.
FIG. 5 is a microphotograph which shows the shape of an actual solder joint in the electromechanical assembly of FIG. 1 before it was stretched.
FIG. 6 is a microphotograph of the same solder joint as shown in FIG. 5 after it was stretched by the fixture and apparatus of FIGS. 1 and 2.
FIG. 7 is a top view of the fixture in FIGS. 1 and 2 which shows additional details of that fixture.
FIG. 8 is a sectional view of the fixture of FIG. 7 taken along lines 8--8.
FIG. 9 is a top view of another fixture which can be used as an alternative to the fixture of FIGS. 7 and 8.
FIG. 10 is a cross-sectional side view, taken along section lines 10--10 in FIG. 11, of still another fixture and apparatus which can be used in place of the fixture and apparatus of FIGS. 1 and 2 to stretch solder joints in accordance with the present invention.
FIG. 11 is a sectional top view of the FIG. 10 fixture and apparatus, takes along section lines 11-11 in FIG. 10.
DETAILED DESCRIPTION
Referring now to FIG. 1, it shows an electromechanical assembly 10 which is about to be processed in accordance with the present invention. That assembly 10 includes an integrated circuit die 11 and a substrate 12 which are attached to each other by a set of solder joints 13.
In the FIG. 1 assembly 10, the die 11 and the substrate 12 and the solder joints 13 are conventional in structure. Thus, the die 11 can contain any type of circuitry such as CMOS circuitry and/or bipolar circuitry. Likewise, the substrate 12 can be any type of substrate such as a multi-layer ceramic substrate or a multi-layer epoxy glass substrate.
Electrical signals, including power and ground, travel between the die 11 and the substrate 12 through the solder joints 13. These signals are routed within the substrate 12 by conventional microscopic conductors (not shown) to the substrates input/output pins 12a.
Each solder joint 13 extends from a microscopic input/output pad on the die 10 to a corresponding input/output pad on the substrate 12. These pads are too small to be shown in FIG. 1; but they too are conventional in structure. Suitably, each input/output pad is simply a circular or approximately circular node on a patterned metal line of about 150 um diameter.
Initially, each solder joint 13 has a conventional height of about 125 um; and it has a conventional convex shape. But, by the process of the present invention, the height of each solder joint will be increased by 25% to 150%, and at an increase of about 40% its shape will be changed from convex to concave.
In FIG. 1, the process of elongating the solder joints 13 is carried out by a fixture 20 and a die moving apparatus 30. All the component parts of the die moving apparatus 30 are identified below in Table 1.
TABLE 1
Item 31 . . . a vacuum head
Item 32 . . . gaskets
Item 33 . . . a quartz disk
Item 34 . . . an infrared lamp
Item 35 . . . a parabolic reflector
Item 36 . . . a bracket
In operation, the fixture 20 is placed over and around the chip 11 as shown in FIG. 1. Then, the die moving apparatus 30 is placed on top of the fixture 20 as is also shown in FIG. 1. Thereafter, the infrared lamp 34 is turned-on; and as a result, infrared radiation 34' is directed by the parabolic reflector 35 through the quartz disk 33 onto the integrated circuit die 11. Thus the integrated circuit die heats up which in turn causes the solder joints 13 to melt.
While the solder joints are melted, a vacuum 37 is applied to a port 31a in the vacuum head 31; and that vacuum causes the integrated circuit die 11 to move in the fixture 20 away from the substrate 12. Due to this movement, the solder joints 13 are stretched; and the stretching continues until the integrated circuit die 11 hits the top section 21 of the fixture 20. This is shown in FIG. 2. wherein the stretched solder joints are identified by reference numeral 13'.
As the integrated circuit die 11 is held by the vacuum 37 in its FIG. 2 position, the infrared lamp 34 is turned-off. Consequently, the stretched solder joints 13' cool and resolidify. Then, the process is completed by removing the vacuum from the port 31a, moving the assembly 30 off of the fixture 20, and removing the fixture 20 from the integrated circuit die 11.
A critical point about the above described process is that as the FIG. 1 solder joints 13 are stretched to the FIG. 2 solder joints 13', the force which those solder joints exert upon the die 11 to oppose the vacuum first increases and then decreases. Consequently, if the movement of the chip 11 was not stopped by the top section 21 of the fixture 20, the vacuum would pull the die 11 away from the substrate 12 until all of the solder joints break. This point is evident from FIGS. 3 and 4.
In FIG. 3, reference numeral 40 shows the initial cross-sectional shape of a single solder joint 13 within the assembly 10 of FIG. 1. That initial shape 40 occurs when no vacuum force (F=F 0 =zero) is being applied to the melted solder joint.
By comparison, reference numerals 41-44 show how the cross-sectional shape of the melted solder joint +14 changes as a non-zero vacuum force is applied to the joint. Shape 41 occurs when a force F=F 1 is applied to/resisted by the joint; shape 42 occurs when a force F=F 2 is applied to/resisted by the joint; etc.
Inspection of FIG. 4 shows that each solder joint initially resists the vacuum with an increasing amount of force until a certain maximum force F M is reached. This maximum resisting force F M occurs when the melted solder joint has a cylindrical shape with an approximately uniform radius.
Thereafter, when the melted solder joint takes on a concave shape, the amount of force which the joint can resist decreases as the joint stretches longer. Consequently, the concave shapes cannot be achieved by simply pulling on the die with a fixed predetermined force.
Further, in a mass production environment, the initial convex shape 40 can not even be stretched to the convex shape 41 by simply pulling on the die with a fixed predetermined force. That is because the amount of solder in each joint will have a certain tolerance. Thus, the zero force height h 0 of each joint will vary; and FIG. 4 shows that a slight increase in the force F 1 will make it equal or exceed the maximum force F M . Consequently, an applied force F=F 1 will cause the small volume solder joints to stretch until they break.
Likewise, in a mass production environment, the accuracy with which the force F M can be externally applied to each solder joint will have a certain tolerance. Consequently, since the difference between the FIG. 4 force F 1 and the maximum force F M is so small (micro Newtons), any practical tolerance added to the force F 1 will cause the resultant force to exceed F M .
Turning now to FIGS. 5 and 6, they are microphotographs which verify the above described process. Specifically, FIG. 5 shows a convex shaped solder joint 13 as it occurs in the FIG. 1 assembly 10; and FIG. 6 shows the same solder joint after it was stretched by the process FIGS. 1 and 2. A comparison of the FIG. 5 solder joint to the FIG. 6 solder joint clearly shows that its shape has been changed from convex to concave. In FIG. 5 the height of the solder joint is three mils whereas in FIG. 6 the height of the solder joint is 7 mils. Magnification in FIGS. 5 and 6 is X400.
To enable the microphotographs of FIGS. 5 and 6 to be taken, the die 11 in the assembly 10 was replaced with a transparent piece of quartz which has the exact same shape and exact same input/output pads as the die 11. That permitted the microphotographs to be taken through the transparent quartz. If an actual die was used, that die would have to be removed to obtain FIG. 6; and removal of the die could distort the stretched solder joints 13'. However, the quartz did introduce glare into the photo's, and this is seen, for example, in FIG. 6. There, the bright area on the conductor next to the bottom of the solder joint is simply glare.
Next, with reference to FIGS. 7 and 8, additional structural details of the fixture 20 will be described. As those figures show, the fixture 20 has a thin flat top section 21 with a square perimeter. Also the fixture has four legs 22a-22d that respectively extend from the four sides of the top section 21. Further, the top section 21 of the fixture has an aperture 23 which enables the infrared radiation 34' to pass through the fixture and melt the solder joints. Suitably, the fixture 20 is made of metal or ceramic or plastic.
Each of the legs 22a-22d extends a distance "D" from the top section 21; and that distance determines the amount "S" by which tile solder joints 13 will be stretched. In particular, "D" equals die thickness plus initial solder joint height plus "S". For example, suppose that the integrated circuit die 11 in FIG. 1 is 500 microns thick and the solder joints 13 are 125 microns high. In that case, the distance "D" for each of the legs will be precisely machined to 625+S microns.
Also in the fixture 20 of FIGS. 7 and 8, the legs 22a and 22c, and the-legs 22b and 22d, are spaced apart by respective distances W1 and W2 which are just slightly larger than the integrated circuit die 13. As a result, the legs prevent the die from rotating and/or moving laterally as it is moved by the vacuum against the top section 21.
Next, referring to FIG. 9, it shows another fixture 50 which can be used in place of the above described fixture 20 in the process of FIGS. 1 and 2. Using this fixture 50, square die having a range of different widths as well as rectangular die having a range of different lengths and widths can be held in place while the process of FIGS. 1 and 2 is carried out. Likewise, the fixture 40 accommodates die length and width tolerances.
To hold these various shaped die, the fixture 50 has two movable arms 51a and 5lb; and those arms are respectively forced against the die as shown by respective springs 52a and 52b. Also, the fixture 50 has four legs 53a-53d which extend from a top section 54 by the distance D which sets the amount S by which the solder joints on the die are stretched, just like the legs 22a-22d in the fixture 20.
Next, referring to FIGS. 10 and 11, they show still another fixture 60 and another die moving apparatus 70 which together operate to stretch the solder joints 13 in the electromechanical assembly 10. As those figures show, the fixture 60 is comprised of two identical clamps 61 and 61'. Each clamp has a base 61a and a pair of guides 6lb and 61c. To hold the base 61a in place, a screw 61d is provided which passes through a washer 61e and a hole 61f in the base and into an underlying table. Hole 61f is about twice as wide as the diameter of the screw 61d to allow the base to be moved such that the guides just barely touch the die. When the guides are in that position, the screw 61d is tightened. Also as shown in FIGS. 10 and 11, the die moving apparatus 70 includes the following items: a stepping motor driven micro displacement stage 71, a bracket 72 which is moved in increments Δx by the stepping motor in stage 71, a set of four springy arms 73a-73d which extend in a cantilevered fashion away from the bracket 72, an infrared lamp 74, and a parabolic reflector 75. All of these items are interconnected as shown in FIG. 10.
In operation, the clamps 61 and 61' are positioned such that the guides 6lb and 61c just barely touch the sides on two diagonally facing corners of the die. In that position, the guides prevent lateral and rotational movement of the die; but they permit the die to move in the vertical direction.
Next, the four springy arms 73a-73d are positioned as shown in FIGS. 10 and 11 such that they hold the die 11 by its four sides. In the illustrated position, two of the arms 73a and 73c operate as one pair of springs which push towards each other; and the other two arms 73b and 73d operate as another pair of springs which push towards each other.
Thereafter the infrared lamp 74 is turned on to thereby melt the solder joints 13. As those solder joints melt, the die 11 remains stationary because any vertical and rotational movement is prevented by the guides 61a and 6lb, and any vertical movement is prevented by the four springy arms 73a-73d.
While the solder joints 13 are completely melted, those solder joints are stretched by sending electrical signals to the stepping motor in stage 71 via conductors 71a which cause the bracket 72 to move a predetermined number "N" of increments "ΔX ". Each time the bracket 72 moves by one of the Δx increments, the solder joints 13 get stretched by the same amount; and thus the total amount by which the solder joints get stretched is S=(N)(ΔX).
A primary feature of the above described process is that it precisely controls the distance by which the solder joints 13 are stretched, even when the electromechanical assembly 10 has several dimensional tolerances. Such tolerances include a thickness variation on the die 11, a flatness variation on the substrate 12, and a volume variation in each solder joint. This feature is achieved because the springy arms 73a-73d hold the integrated circuit die by its sides. Thus, even though the initial height x 0 of the die 11 varies relative to the substrate, and the stretching increments Δx will always be referenced to that initial height.
After the solder joints 13 have been stretched by the desired number of Δx increments, the infrared lamp 74 is turned off. Then the solder joints are allowed to resolidify, and the stretching operation is complete.
Several preferred methods for stretching solder joints in electromechanical assembly in accordance with the present invention have now been described in detail. In addition however, various changes and modifications can be made to those details without departing from the nature and spirit of the invention.
For example, when the present invention is used, the solder joints which are stretched may be composed of any type of solder. Thus, the solder can have any predetermined chemical composition; and it can have any predetermined melting temperature.
Likewise, in the above described processes, the electromechanical assembly which contains the solder joints that are to be stretched can have any desired configuration. Thus, for example, the substrate 12 can be increased in size and multiple integrated circuit die can be soldered to it. Also, the substrate can be made of any desired materials. For example, the substrate can be a co-fired multi-layer ceramic substrate, or it can be a multi-layer epoxy glass substrate.
Also, in the above described methods, the integrated circuit die can be attached to the substrate by any number of solder joints; and those solder joints can be arranged in any predetermined pattern. Further, the integrated circuit die itself can, as an alternative, be replaced with any desired electrical component. For example, the die 11 can be replaced with a surface mount type of ceramic integrated circuit package.
Further, as still another variation, an additional step can be performed at the start of the above described processes wherein the electromechanical assembly is preheated to a temperature which is slightly below the melting temperature of the solder joints. Suitably, this preheating is achieved by placing the assembly on a hot plate. By this process variation, thermally induced stresses within the assembly are reduced when the solder is subsequently melted by the infrared lamp.
Likewise, as another variation, the infrared lamp can be replaced with a different heating source. For example, the heating source can be an oven in which the assembly is placed or a stream of hot gas.
Further, as yet another variation, another step can be added to the above described processes wherein the assembly is immersed in an inert gas while the solder joints are melted and stretched. Suitably, the inert gas is nitrogen. With this process variation, oxidation of the solder joints is prevented; and that is desired because some solders become more brittle if they oxidize.
Further, as still another process variation, the stepping motor stage 71 of FIG. 10 can be replaced with a manually driven stage which will precisely move the bracket 72 either in increments, or continuously. Preferably, the mechanism includes an accurate measuring instrument, such as a micrometer, to measure the amount by which the bracket 72 is moved. An example of a suitable motor driven stage 71 as well as an example of a suitable manually driven stage respectively are the model UT100-PP and the model UT100-MN from Klinger Scientific Corporation of Garden City, N.Y. | A method of stretching solder joints between the input/output pads of an electrical component and corresponding input/output pads on a substrate includes the steps of: melting the solder joints; confining the component while the solder joints are melted such that the component can only move substantially perpendicular to the substrate; pulling the component, while the component is confined, by an external force in a direction away from the substrate to thereby stretch the melted solder joints; compelling the movement of the component to stop when the component has moved a predetermined distance; and, solidifying the solder joints while the component is compelled to stop. By stretching the solder joints with the above method, the solder joint shape can be changed from convex to concave; and thermally induced stress/strain in the joint is substantially reduced. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit under 35 U.S.C. §120 of (and is a continuation of) U.S. patent application Ser. No. 10/706,398, filed Nov. 12, 2003, which in turn claims the benefit under 35 U.S.C. §120 of (and is a continuation of) U.S. patent application Ser. No. 10/208,093, now U.S. Pat. No. 6,697,868, which in turn claims the benefit under 35 U.S.C. §120 of (and is a continuation-in-part of) U.S. patent application Ser. No. 09/514,425, filed Feb. 28, 2000, now U.S. Pat. No. 6,427,171, which in turn claims the benefit under 35 U.S.C. §120 of (and is a continuation-in-part of): a) U.S. patent application Ser. No. 09/141,713, filed Aug. 28, 1998, now U.S. Pat. No. 6,389,479, which in turn claims the benefit under 35 U.S.C. §119 of provisional application 60/098,296, filed Aug. 27, 1998; b) U.S. patent application Ser. No. 09/067,544, filed Apr. 27, 1998, now U.S. Pat. No. 6,226,680, which in turn claims the benefit under 35 U.S.C. § 119 of provisional application 60/061,809, filed Oct. 14, 1997; and c) U.S. patent application Ser. No. 09/384,792, filed Aug. 27, 1999, which in turn claims the benefit under 35 U.S.C. §119 of provisional application 60/098,296, filed Aug. 27, 1998.
[0002] U.S. Pat. No. 6,697,868 also claims the benefit under 35 U.S.C. §120 of (and is a continuation-in-part of) U.S. patent application Ser. No. 09/464,283, filed Dec. 15, 1999, now U.S. Pat. No. 6,427,173, which in turn claims the benefit under 35 U.S.C. §120 of (and is a continuation-in-part of) U.S. patent application Ser. No. 09/439,603, filed Nov. 12, 1999, now U.S. Pat. No. 6,247,060, which in turn claims the benefit under 35 U.S.C. §120 of (and is a continuation-in-part of) U.S. patent application Ser. No. 09/067,544, filed Apr. 27, 1998, now U.S. Pat. No. 6,226,680, which in turn claims the benefit under 35 U.S.C. §119 of provisional application 60/061,809, filed Oct. 14, 1997.
[0003] The subject matter of all of the applications listed above and patents listed above is incorporated herein by reference.
REFERENCE TO COMPACT DISC APPENDIX
[0004] The Compact Disc Appendix (CD Appendix), which is a part of the present disclosure, includes three folders, designated CD Appendix A, CD Appendix B, and CD Appendix C on the compact disc. CD Appendix A contains a hardware description language (verilog code) description of an embodiment of a receive sequencer. CD Appendix B contains microcode executed by a processor that operates in conjunction with the receive sequencer of CD Appendix A. CD Appendix C contains a device driver executable on the host as well as ATCP code executable on the host. A portion of the disclosure of this patent document contains material (other than any portion of the “free BSD” stack included in CD Appendix C) which is subject to copyright protection. The copyright owner of that material has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights.
TECHNICAL FIELD
[0005] The present invention relates to the management of information communicated via a network, including protocol processing.
BACKGROUND
[0006] Various individuals, companies and governments have worked for many years to provide communication over computer networks. As different computer and network architectures have been created, many types of protocols have evolved to facilitate that communication. Conventionally, network messages contain information regarding a number of protocol layers that allow information within the messages to be directed to the correct destination and decoded according to appropriate instructions, despite substantial differences that may exist between the computers or other devices transmitting and receiving the messages. Processing of these messages is usually performed by a central processing unit (CPU) running software instructions designed to recognize and manipulate protocol information contained in the messages.
[0007] With the increasing prevalence of network communication, a large portion of the CPU's time may be devoted to such protocol processing, interfering with other tasks the CPU may need to perform. Multiple interrupts to the CPU can also be problematic when transferring many small messages or for large data transfers, which are conventionally divided into a number of packets for transmission over a network.
SUMMARY
[0008] In accordance with the present invention, means for offloading some of the most time consuming protocol processing from a host CPU to a specialized device designed for network communication processing are provided. The host has a protocol processing stack that provides instructions not only to process network messages but also to allocate processing of certain network messages to the specialized network communication device. By allocating some of the most common and time consuming network processes to the network communication device, while retaining the ability to handle less time intensive and more varied processing on the host stack, the network communication device can be relatively simple and cost effective. The host CPU, operating according to the instructions from the stack, and the specialized network communication device together determine whether and to what extent a given message is processed by the host CPU or by the network communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic plan view of a host computer having an intelligent network interface card or communication processing device (INIC/CPD) connected to a remote host via a network.
[0010] FIG. 2 is a schematic plan view of a protocol processing stack of the present invention passing a connection context between host storage and the INIC/CPD.
[0011] FIG. 3 is a diagram of a general method employed to process messages received by the host computer via the INIC/CPD.
[0012] FIG. 4 illustrates a handout of the connection context from the host protocol processing stack to the INIC/CPD via a miniport driver installed in the host.
[0013] FIG. 5 shows a return of the connection context to the host protocol processing stack from the INIC/CPD via a miniport driver installed in the host.
[0014] FIG. 6 diagrams a control mechanism for transmitting a message via the fast-path.
[0015] FIG. 7 diagrams a control mechanism for receiving a message via the fast-path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring now to FIG. 1 , the present invention can operate in an environment including a host computer shown generally at 20 connected to a remote host 22 via a network 25 . The host 20 includes a central processing unit (CPU) 28 and storage 35 , while an intelligent network interface card or communication processing device (INIC/CPD) 30 provides an interface between the host and the network 25 . A computer is defined in the present invention to be a device including a CPU, a memory and instructions for running the CPU. The network 25 is a medium for transmission of information from one computer to another, such as conductive wires, optical fibers or wireless space, including any supporting hardware or software such as switches and routers. Network implementations include local area networks, wide area networks, telecommunication networks and the Internet. The INIC/CPD 30 is depicted on a border of host 20 because the INIC/CPD provides a network interface that may be added with an adapter card, for example, or integrated as a part of the host computer. A bus 33 such as a peripheral component interface (PCI) bus provides a connection within the host 20 between the CPU 28 , the INIC/CPD 30 , and a storage device 35 such as a semiconductor memory or disk drive, along with any related controls.
[0017] Referring additionally to FIG. 2 , the host CPU 28 runs a protocol processing stack 44 of instructions stored in storage 35 , the stack including a data link layer 36 , network layer 38 , transport layer 40 , upper layer 46 and an upper layer interface 42 . A general description of these protocol layers can be found in the book by W. Richard Stevens entitled TCP/IP Illustrated, Volume 1 (13 th printing, 1999), which is incorporated herein by reference. The upper layer 46 may represent a session, presentation and/or application layer, depending upon the particular protocol being employed and message communicated. The upper layer interface 42 , along with the CPU 28 and any related controls can send or retrieve data to or from the upper layer 46 or storage 35 , as shown by arrow 48 . The upper layer interface 42 may be called a Transport driver interface (TDI), for example, in accord with Microsoft terminology. A connection context 50 has been created, as will be explained below, the context summarizing various features of a message connection, such as the protocol types, source and destination addresses and status of the message. The context 50 may be passed between an interface for the session layer 42 and the INIC/CPD 30 , as shown by arrows 52 and 54 , and stored as a communication control block (CCB) of information in either an INIC/CPD 30 memory or storage 35 .
[0018] When the INIC/CPD 30 holds a CCB defining a particular connection, data received by the INIC/CPD from the network and pertaining to the connection is referenced to that CCB and can then be sent directly to storage 35 according to a fast-path 58 , bypassing sequential protocol processing by the data link 36 , network 38 and transport 40 layers. Transmitting a message, such as sending a file from storage 35 to remote host 22 , can also occur via the fast-path 58 , in which case the context for the file data is added by the INIC/CPD 30 referencing the CCB, rather than by sequentially adding headers during processing by the transport 40 , network 38 and data link 36 layers. The DMA controllers of the INIC/CPD 30 can perform these message transfers between INIC/CPD and storage 35 .
[0019] The INIC/CPD 30 can collapse multiple protocol stacks each having possible separate states into a single state machine for fast-path processing. The INIC/CPD 30 does not handle certain exception conditions in the single state machine, primarily because such conditions occur relatively infrequently and to deal with them on the INIC/CPD would provide little performance benefit to the host. A response to such exceptions can be INIC/CPD 30 or CPU 28 initiated. The INIC/CPD 30 deals with exception conditions that occur on a fast-path CCB by passing back or flushing to the host protocol stack 44 the CCB and any associated message frames involved, via a control negotiation. The exception condition is then processed in a conventional manner by the host protocol stack 44 . At some later time, usually directly after the handling of the exception condition has completed and fast-path processing can resume, the host stack 44 hands the CCB back to the INIC/CPD. This fallback capability enables most performance-impacting functions of the host protocols to be quickly processed by the specialized INIC/CPD hardware, while the exceptions are dealt with by the host stacks, the exceptions being so rare as to negligibly effect overall performance.
[0020] FIG. 3 diagrams a general flow chart for messages sent to the host via the network according to the current invention. A large TCP/IP message such as a file transfer may be received by the host from the network in a number of separate, approximately 64 KB transfers, each of which may be split into many, approximately 1.5 KB frames or packets for transmission over a network. Novel NetWare® protocol suites running Sequenced Packet Exchange Protocol (SPX) or NetWare® Core Protocol (NCP) over Internetwork Packet Exchange (IPX) work in a similar fashion. Another form of data communication which can be handled by the fast-path is Transaction TCP (hereinafter T/TCP or TTCP), a version of TCP which initiates a connection with an initial transaction request after which a reply containing data may be sent according to the connection, rather than initiating a connection via a several-message initialization dialogue and then transferring data with later messages. In general, any protocol for which a connection can be set up to define parameters for a message or plurality of messages between network hosts may benefit from the present invention. In any of the transfers typified by these protocols, each packet conventionally includes a portion of the data being transferred, as well as headers for each of the protocol layers and markers for positioning the packet relative to the rest of the packets of this message.
[0021] When a message packet or frame is received 47 from a network by the INIC/CPD, it is first validated by a hardware assist. This includes determining the protocol types of the various layers of the packet, verifying relevant checksums, and summarizing 57 these findings into a status word or words. Included in these words is an indication whether or not the frame is a candidate for fast-path data flow. Selection 59 of fast-path candidates is based on whether the host may benefit from this message connection being handled by the INIC/CPD, which includes determining whether the packet has header bytes denoting particular protocols, such as TCP/IP or SPX/IPX for example. The typically small percentage of frames that are not fast-path candidates are sent 61 to the host protocol stacks for slow-path protocol processing. Subsequent network microprocessor work with each fast-path candidate determines whether a fast-path connection such as a TCP or SPX CCB is already extant for that candidate, or whether that candidate may be used to set up a new fast-path connection, such as for a TTCP/IP transaction. The validation provided by the INIC/CPD provides advantages whether a frame is processed by the fast-path or a slow-path, as only error free, validated frames are processed by the host CPU even for the slow-path processing.
[0022] All received message frames which have been determined by the INIC/CPD hardware assist to be fast-path candidates are examined 53 by the network microprocessor or INIC comparator circuits to determine whether they match a CCB held by the INIC/CPD. Upon confirming such a match, and assuming no exception conditions exist, the INIC/CPD removes lower layer headers and sends 69 the remaining application data from the frame directly into its final destination in the host using direct memory access (DMA) units of the INIC/CPD. This operation may occur immediately upon receipt of a message packet, for example when a TCP connection already exists and destination buffers have been negotiated, or it may first be necessary to process an initial header to acquire a new set of final destination addresses for this transfer. In this latter case, the INIC/CPD will queue subsequent message packets while waiting for the destination address, and then DMA the queued application data to that destination. The final destination addresses may be provided as a scatter-gather list of host buffer address and length pairs. For a Microsoft type operating system and stack 44 , the scatter gather list is a memory descriptor data list (MDL).
[0023] A fast-path candidate that does not match a CCB may be used to set up a new fast-path connection, by sending 65 the frame to the host for sequential protocol processing. In this case, the host uses this frame to create 51 a CCB, which is then passed to the INIC/CPD to control subsequent frames on that connection. The CCB, which is cached 67 in the INIC/CPD, includes control and state information pertinent to all protocols that would have been processed had conventional software layer processing been employed. The CCB also contains storage space for per-transfer information used to facilitate moving application-level data contained within subsequent related message packets directly to a host application in a form available for immediate usage. The INIC/CPD takes command of connection processing upon receiving a CCB for that connection from the host.
[0024] As mentioned above, the present invention improves system performance by offloading TCP/IP data processing from the host protocol stack to the INIC/CPD. Since only the data movement portion of the protocol stack is offloaded, TCP control processing generally remains on the host protocol stack. In addition, the host protocol stack also handles TCP exception processing, such as retransmissions. Leaving TCP control and exception processing on the host protocol stack has the advantage of giving the operating system complete control over the TCP connection. This is convenient because the operating system may choose not to hand out a connection to the network communication device for various reasons. For example, if someone wishes to monitor network frames on the host, the host protocol stack can be programmed to handle all TCP connections, so that no packets are processed on the INIC/CPD. A second advantage to leaving TCP control and exception processing on the host protocol stack is that this greatly simplifies the complexity of operations required by the INIC/CPD, which can be made from an inexpensive application specific integrated circuit (ASIC) as opposed to an expensive CPU.
[0025] In order for a connection to be handled by both the host protocol stack 44 for control and exception conditions, and by the INIC/CPD 30 for data movement, the connection context is made to migrate between the host and the INIC/CPD. A CCB, which contains the set of variables used to represent the state of a given TCP connection, provides the mechanism for this migration. Transfer of a CCB from the host to the INIC/CPD is termed a connection handout, and transfer of a CCB from the INIC/CPD back to the host is termed a connection flush. This transfer may occur several times during the course of a TCP connection as the result of dropped packets or other exceptions, which are discussed below. Once a connection handout occurs, the INIC/CPD handles all TCP processing, according to the fast-path mode. Any message transmissions occurring while in the fast-path mode are referred to as fast-path sends. Likewise, any message receptions that occur while in the fast-path mode are referred to as fast-path receives.
[0026] A portion of the CCB corresponds to a conventional TCP control block, containing items such as sequence numbers and ports, as well as lower protocol values such as IP addresses and the first-hop MAC addresses. A list of variables for such a conventional TCP control block can be found in the book by Gary R. Wright and W. Richard Stevens entitled TCP/IP Illustrated, Volume 2 (7 th Edition, 1999), which is incorporated by reference herein, on pages 803-805.
[0027] In addition to those TCP variables, a number of variables are provided in the CCB for maintaining state information involving the present invention. A first of these variables, a character termed conn_nbr, denotes the connection number for this CCB. The INIC/CPD 30 may maintain, for example, 256 connections, so that the conn_nbr delineates which of those connections is defined by this CCB. Another CCB-specific variable is termed hosttcbaddr, which lists the address in the host for this particular CCB. This address is used when the CCB is returned from the INIC/CPD to the host. For accelerated processing of the most active connections, the INIC/CPD 30 stores the connections in a hash table in SRAM. A CCB variable termed HashValue gives a hash table offset for the CCB, which is a hash of the source and destination IP addresses, and source and destination TCP ports for the connection.
[0028] Another character, termed buff_state, tells whether a CCB that has been cached in SRAM matches the corresponding CCB stored in DRAM. After processing of a frame or burst of frames against an SRAM cached connection, the state of the CCB is changed, which is indicated by the buff_state character. When the cached connection is flushed back by DMA to DRAM, replacing the CCB held in DRAM with the SRAM CCB having updated status, the character buff_state is set clean.
[0029] Additional variables contained in a CCB include a character termed rcv_state, which denotes the status of a receive finite state machine for the CCB, and a character termed xmt_state, which denotes the status of a transmit finite state machine for the CCB. Both of these state machines pertain to fast path processing by the INIC/CPD 30 . In other words, the state of a fast path receive state machine for a given CCB can be defined by a number of different values indicated by the setting of the rcv_state character, and the state of a fast path transmit state machine for that CCB can be likewise be defined by the setting of the xmt_state character. Events processed against the receive and transmit state machines are denoted in the CCB by characters labeled rcv_evts and xmt_evts, respectively. These event characters offer a history of events that have transpired as well as the current events affecting those state machines. For example, the rcv_evts character may contain eight bits defining previous events and another eight bits defining current events, with the xmt-evts character similarly apportioned.
[0030] Also contained in a CCB are variables associated with frames that have been received by the INIC/CPD 30 corresponding to the connection. For example, fast path received frames may accumulate in the host while the INIC/CPD 30 is waiting for an MDL delineating a host destination for the received message. A CCB field termed RcvQ[RCV_MAX] offers a number of thirty-two-bit words for storing pointers to such frames in DRAM, essentially forming a receive queue. A CCB variable termed OflIO (for overflow input/output pointers), offers information corresponding to the RcvQ, such as pointers to the last frame in and first frame out, while a variable termed QdCnt indicates the number of frames in the RcvQ.
[0031] A number of CCB variables pertain to the MDL that has been provided for storing a received message. A character termed RHHandle is used to report to the host a command that has been completed by the INIC/CPD 30 regarding that MDL. RNxtDAdd is a CCB field that is used to denote the next scatter/gather address list to be acquired from DRAM in the INIC/CPD 30 for storage according to the MDL. The variable RCurBuff describes the current buffer of the MDL for storing data, and RCurLen tells the length of that buffer. Similarly, the variable RNxtBuff tells the next receive buffer from the MDL for storing data, and RNxtLen tells the length of that buffer. RTotLen is used to designate the total length of the MDL, which is reduced as data is stored in the buffers designated by the MDL.
[0032] The CCB similarly keeps track of buffer queues during transmission of a message. The variable XNxtDAdd pertains to the next address in INIC/CPD 30 DRAM from which to acquire a scatter/gather list of data to be sent over a network; while XTotLen provides the total length of the data to be sent, which is reduced as data is sent. The variable XCurBuff describes the current host buffer from which to send data, and XCurLen tells the length of that buffer. Similarly, the variable XNxtBuff tells the next host buffer from which data is acquired, and XNxtLen tells the length of that buffer.
[0033] Some CCB variables pertain to commands sent from the host stack 44 to the INIC/CPD 30 during transmission of a message. Several commands sent by the host regarding a particular CCB may be processed at one time by the INIC/CPD 30 , and the CCB maintains variables keeping track of those commands. A variable termed XRspSN holds a TCP sequence number for each message that has been sent over a network. This TCP sequence number is used for matching with an acknowledgement (ACK) from the remote host of receipt of that transmission. A variable termed XHHandle provides a handle or DRAM address of the host regarding a particular command, so that for example upon receiving such an ACK the INIC/CPD can notify the host. CCB variables that keep track of commands being processed by the INIC/CPD include XCmdIn, which tells the next command storage slot, XCmdOut, which describes the command to be executed, and XCmd2Ack, which points to commands that have been sent but not yet ACKed. XCmdCnts lists the number of commands currently being processed and commands that have been sent but not yet ACKed. XmtQ provides a queued list of all the commands being processed by the INIC/CPD.
[0034] The CCB also contains a couple of fields for IP and TCP checksums, termed ip_ckbase and tcp_ckbase, respectively. Fast-path transmission of a message occurs with the INIC/CPD prepending protocol headers derived from the CCB to message data provided by the host for the CCB. The ip_ckbase and tcp_ckbase offer the possibility of adjusting the base checksums provided by the host for prepending to the data along with the headers.
[0035] As mentioned above, fast-path operations can be divided into four categories: handout, flush, send and receive. These fast-path operations may be implemented in the form of a generic Microsoft Task Offload (TCP_TASK_OFFLOAD), which may be independent from the specific hardware of the INIC/CPD 30 . For the currently preferred implementation, hardware-specific code is placed in the NDIS miniport driver. Implementations for other protocol processing stacks, such as for Unix, Linux, Novel or Macintosh operating systems, may also be hardware-independent. The present invention illustrates a Microsoft stack implementation since it involves one of the most popular operating systems, and substantial improvements are provided. The description below illustrates the modifications required to integrate the four basic fast-path operations into the Microsoft TCP/IP protocol processing stack. Also defined is the format of the TCP_TASK_OFFLOAD as well as miscellaneous issues associated with these changes.
[0036] Support for the fast-path offload mechanisms requires the definition of a new type of TCP_TASK_OFFLOAD. As with other task offloads, TCP will determine the capabilities of the NDIS miniport by submitting an OID_TCP_TASK_OFFLOAD OID to the driver.
[0037] Fast-path information is passed between the protocol processing stack 44 and the miniport driver 70 as media specific information in an out-of-band data block of a packet descriptor. There are two general fast-path TCP_TASK_OFFLOAD structures—commands and frames. The TCP_OFFLOAD_COMMAND structure contains fast-path information that is being sent from the TCPIP driver to the miniport. The TCP_OFFLOAD_FRAME structure contains fast-path information being sent from the miniport to the TCPIP driver. The header file that defines the fast-path TCP_TASK_OFFLOAD mechanism is described on a later page.
[0038] Six types of offload commands are defined below:
[0039] 1] TCP_OFFLOAD_HANDOUT1 (this is the first phase of a two-phase handshake used in the connection handout);
2] TCP_OFFLOAD_HANDOUT2 (this is the second phase of the two-phase handshake used in the connection handout); 3] TCP_OFFLOAD_FLUSH (this command is used to flush a connection); 4] TCP_OFFLOAD_SENDMDL (this command is used to send fast-path data); 5] TCP_OFFLOAD_RCVMDL (this is the command used to pass an MDL scatter gather list to the INIC/CPD for receive data); 6] TCP_OFFLOAD_WINUPDATE (this command is used to send a TCP window update to the INIC/CPD); and 7] TCP_OFFLOAD_CLOSE (This command is used to close a TCP connection that is on the INIC/CPD).
[0046] Three types of offload frames are defined below:
1) TCP_OFFLOAD_FRAME_INTERLOCK (this is part of the two-phase handshake used in the connection handout); 2) TCP_OFFLOAD_FLUSH (this is used by the miniport to flush a connection to the host); 3) TCP_OFFLOAD_FRAME_DATA (this is used to indicate newly arrived fast-path data).
[0050] FIG. 4 illustrates the migration of a connection context during a handout from the host protocol processing stack 44 to the INIC/CPD 30 via a miniport driver 70 installed in the host 20 . Two of the TCP offload commands and one of the TCP offload frames that were defined above are illustrated here. The miniport driver 70 converts these commands into hardware specific interactions with the INIC/CPD 30 .
[0051] The connection handout is implemented as a two-phase operation to prevent race conditions. If instead a handout were attempted in a single-phase operation, there could be a period of time during which the protocol processing stack 44 had issued the handout but the INIC/CPD 30 had not yet received the handout. During this time, slow-path input data frames could arrive and be processed by the protocol processing stack 44 . Should this happen, the context information, which the protocol processing stack 44 passed to the INIC/CPD 30 , would no longer be valid. This potential error is avoided by establishing a provisional context on the INIC/CPD 30 with the first handout command.
[0052] Thus a handout of a CCB from the stack 44 to the INIC/CPD 30 for a connection to be processed by the fast-path occurs in several steps. First, a TCP_OFFLOAD_HANDOUT1 100 is sent from the stack 44 to the miniport driver 70 , which issues a Handout1 command 102 to the INIC/CPD 30 . The INIC/CPD 30 sends an interlock frame 105 to the miniport driver 70 upon receipt of the handout1 command 102 , and internally queues any subsequent frames for the specified connection. Upon receipt of the interlock frame 105 , the miniport driver 70 sends a TCP_OFFLOAD_FRAME_INTERLOCK frame 108 to the stack 44 , which interprets frame 108 as a signal that no further slow-path frames are expected. Stack 44 thereupon completes the handshake by issuing a TCP_OFFLOAD_HANDOUT2 command 110 that includes a CCB, which is forwarded by the miniport driver 70 to the INIC/CPD 30 as a handout2 112 . Upon receipt of the handout2 112 , the INIC/CPD 30 reads the contents of the CCB and begins fast-path processing. Note that the CCB address is passed to the miniport in the TCP_OFFLOAD HANDOUT2 command.
[0053] Once a connection has been placed in fast-path mode by the CCB handout, subsequent fast-path commands will require a way to identify the particular connection. The present invention defines two opaque handles for this purpose. A HostContext handle is a value used to uniquely identify a connection to the protocol processing stack 44 . For TCP/IP messages the value is the address of the TCP control block. This handle is opaque to the miniport driver 70 . A LowerContext handle, on the other hand, is used to uniquely identify the connection to the miniport driver 70 and/or INIC/CPD 30 . This handle is opaque to the host stack 44 , and implementation specific to the miniport driver 70 . Both the HostContext handle and LowerContext handle are contained in the TCP_OFFLOAD_COMMAND structure, while only the HostContext value is contained in the TCP_OFFLOAD_FRAME structure. During a connection handout, the host stack 44 passes down the HostContext field to the miniport driver 70 . The miniport driver 70 returns the LowerContext on completing the handout request.
[0054] The protocol processing stack 44 on the host has responsibility for deciding when a connection is to be handed out to the INIC/CPD 30 . A connection can be handed out to the INIC/CPD 30 as soon as the connection is fully established and any outstanding exceptions have been handled. Nevertheless, the protocol processing stack 44 may choose to not hand out a connection for a variety of reasons. For example, in order to preserve resources on the INIC/CPD 30 , the host stack 44 may choose to not handout out slow connections, such as those employing Telnet. The host stack 44 may also use an heuristic method to determine that a particular connection is too unreliable to warrant putting it in fast-path mode.
[0055] Either the host protocol processing stack 44 or the INIC/CPD 30 can flush a connection, as shown in FIG. 5 . Should the host stack 44 decide to flush a connection, it will issue a TCP_OFFLOAD_FLUSH 120 to the miniport driver 70 , which in turn issues a Flush command 122 to the INIC/CPD 30 , causing the INIC/CPD 30 to flush the connection. When the INIC/CPD 30 flushes the connection to the stack 44 , several operations are performed that result in sending a Flush frame 125 to the miniport driver 70 , which in turn sends a TCP_OFFLOAD_FRAME_FLUSH 128 to the INIC/CPD 30 . For the situation in which the INIC/CPD 30 decides to flush the connection, the signals 120 and 122 do not exist.
[0056] When the INIC/CPD 30 flushes a connection, either by request from the host stack 44 or by its own decision, it performs several procedures. First, any outstanding fast-path send or receive message transfers are completed. When operating in the fast-path mode, a send or receive message transfer may involve 64 kilobytes of data, for example. When a send or receive transfer is terminated, information regarding the data sent or received is flushed to the host so that the stack 44 can continue processing the send or receive operation. In order to do this, the scatter gather list defining the set of host buffer address and length pairs for the send or receive message transfer is passed back to the stack 44 , along with information denoting how much data has already been transferred via the fast-path. Second, the contents of the CCB defining the fast-path connection are also sent from the INIC/CPD 30 back to the host. Note that while a connection is in the fast-path mode, the state of the connection is maintained by the INIC/CPD 30 . This connection state is transferred back to the host so that sequence numbers, etc, are kept in sync. The INIC/CPD 30 does not issue the flush frame to the host stack 44 until both of these steps are complete.
[0057] A connection may be flushed for a variety of reasons. For example, the stack 44 will flush if it receives a TDI_DISCONNECT instruction for the connection, as connection setup and breakdown occurs on the host stack. The INIC/CPD 30 will flush if it encounters a condition that is not allocated to the INIC/CPD for handling, such as expiration of a retransmission timer or receipt of a fragmented TCP segment.
[0058] FIG. 6 diagrams a control mechanism for transmitting a message via the fast-path, which may be initiated by the protocol processing stack 44 receiving a TDI_SEND request for a connection that is in the fast-path mode. The steps for controlling this fast-path send of the message to a remote host via the INIC/CPD 30 are simple. The stack 44 creates a TCP_OFFLOAD_COMMAND with the appropriate context handles, the length of the message to be sent, and a scatter-gather list or send MDL. A virtual to physical address translation is performed by the host stack 44 , although this translation may alternatively be performed by the miniport driver 70 . The fast-path send command will not complete until either all of the data has been sent and acknowledged, or the connection has been flushed back to the host. If the connection is flushed back to the host, a residual field will indicate how much of the send MDL remains to be sent.
[0059] A fast-path receive operation begins when a frame arrives on the INIC/CPD 30 for a connection on which no outstanding receive operation is already in progress. As shown in FIG. 7 , when such a frame is received by the INIC/CPD 30 , some or all of the received frame (depending on the frame size) is forwarded 140 to the miniport driver 70 , which in turn sends 142 a TCP_OFFLOAD_FRAME_DATA frame containing the forwarded information to the host stack 44 . The host stack 44 will in turn communicate with the upper layer interface, which may be a TDI interface for Microsoft systems, calling a receive handler registered by the upper layer or application. The amount of data in the received message frame may be indicated to that host application at this point, which may be termed an indicated length. That frame may also indicate the size of the data for the entire received message, so that a destination for that data can be earmarked within the host, such as with a scatter-gather list. A total message length that may be specified in an initial frame header is termed an available length.
[0060] For example, a NETBIOS message denotes the size of the data in the NETBIOS header, which can optionally be processed by the INIC/CPD 30 and passed to the upper layer interface for earmarking a final host destination in which to place the message data. Alternatively, the host stack 44 can process an initial NETBIOS header and learn how much more data is expected for the NETBIOS request. In cases for which a total message is size is unknown, a fictitious indication of large message length can be communicated to the upper layer interface, causing the application to respond with a large set of destination addresses which should have sufficient storage for the message.
[0061] Continuing with the example of a Microsoft operating system, if the available length is larger than the indicated length, the TDI upper layer or application will provide an I/O request packet (IRP) with an MDL. This MDL is passed down to the miniport driver 70 in the form of a TCP_OFFLOAD_RCVMDL command, which forwards the command to the INIC/CPD 30 . Like the fast-path send command, this command contains the context handles, the length of the receive MDL, and the scatter-gather list contained in the MDL. By passing the MDL directly to the INIC/CPD 30 , the message data is moved directly to the buffer(s) provided by the TDI upper layer or application, without the data being touched by the CPU.
[0062] Subsequent message frames for this connection will be processed solely by the INIC/CPD 30 and moved into the buffers denoted by the MDL until either the MDL is filled or the command is flushed back to the host. If the command is flushed back to the host stack 44 , then the residual field will indicate how much unprocessed data remains for the MDL. If the TCP_OFFLOAD_RCVMDL command is completed without error, then the Tcpip driver will complete the IRP, at which point the system is ready for the next TCP_OFFLOAD_FRAME_DATA indication. For messages whose total size is not discernable from initial received frames, the connection may receive a FIN before the receive MDL is filled. If this occurs a short completion is performed on the receive IRP.
[0063] If the INIC/CPD 30 has been given a host destination such as a scatter-gather list or MDL by an upper layer or application, the INIC/CPD will treat data placed in this destination as being accepted by the upper layer or application. The INIC/CPD 30 may therefore ACK incoming data as it is filling the destination buffer(s) and will keep its advertised receive window fully open.
[0064] For small requests, however, there may be no MDL returned by the upper layer interface such as TDI to the INIC/CPD 30 . In this case all of the data may be absorbed directly in the receive callback function. To account for this, the data which has been accepted by the application is updated to the INIC/CPD 30 so that the INIC/CPD can update its receive window. In order to do this, the host stack 44 can accumulate a count of data which has been accepted by the application receive callback function for a connection. From the INIC/CPD's point of view, though, segments sent to the host destination seem to be just “thrown over the wall” unless there is an explicit reply path. To correct this deficiency, the update may be piggybacked on requests sent to the INIC/CPD 30 , for example via a field in the TCP_OFFLOAD_COMMAND structure. To deal with a scenario in which the data stream is entirely one-way, we can also define a TCP_OFFLOAD_WINUPDATE command type to update the INIC/CPD.
[0065] A converse issue with offloading TCP processing involves keeping host stack 44 TCP/IP statistics up to date. For example, there is no conventional way for the host stack 44 to know how many TCP segments were received by the INIC/CPD 30 . We address this issue by introducing a GET_TCP_STATISTICS OID, which is passed to the miniport driver 70 to obtain the TCP statistics. The way that the miniport and INIC/CPD 30 maintain these statistics depends upon implementations selected for those systems.
[0066] The host stack 44 creates and maintains a performance monitor (Perfmon) extension dynamic link library (DLL), which can be used to monitor fast-path statistics such as the following: 1) Fast-path/slow-path send/receive bytes per second; 2) Fast-path/slow-path send/receive segments per second; 3) Handouts per second; 4) Flushes per second; and 5) Fast-path/slow-path current connections.
[0067] Approximately 2500 lines of code are employed to port the fast-path modifications to the Microsoft host stack 44 , not including comments. The approximate breakdown of this is as follows: 1) Connection handout—550 lines of code; 2) Flush—400 lines of code; 3) Send—550 lines of code; 4) Receive—600 lines of code; and 5) Miscellaneous (e.g., stats. and perfmon)—250 lines of code.
[0068] The fast-path code is implemented in such a way that it requires minimal changes to the existing TCP/IP host stack 44 . Nearly all of the approximately 2500 lines of code are contained within fast-path specific routines, which are in turn kept in a single fast-path specific file. A number of changes to a Microsoft host stack 44 operation provide the appropriate calls into the fast-path code. These changes are summarized below.
[0069] The initialization code queries the adapters for the fast-path TCP_TASK_OFFLOAD feature and sets the appropriate information in the structure representing the adapter. Modifications to the TDI data presentation code are employed to indicate data received. Modifications are also employed where the host stack 44 receives a TDI Send request. The modified stack 44 then recognizes that a connection is in fast-path mode and calls the fast-path send routine.
[0070] After a TCP connection is set up, the host stack 44 checks the capabilities of the adapter associated with the connection, and if appropriate calls the fast-path connection handout routine. Similarly, for a fast-path connection that has been placed into slow-path mode, the host stack code repeats the handout of the connection once the connection returns to a standard state.
[0071] The ProtocolReceivePacket routine of the host stack 44 is modified to identify the existence of fast-path TCP_TASK_OFFLOAD information in the packet. If fast-path information exists, the appropriate fast-path receive routine is called.
[0072] The ProtocolSendComplete routine of the host stack 44 recognizes the completion of a fast-path send, and calls the appropriate fast-path send completion routine.
[0073] The TCP input code recognizes when it has received a slow-path frame on a fast-path connection, which indicates a routing loop. If this occurs the host stack 44 implements the flush code.
[0074] The TCP connection breakdown code recognizes when a connection is in fast path mode and issues a flush before closing the connection.
[0075] Paper Appendix A provides source code, written in a C-type language, defining the TCP_TASK_OFFLOAD structures used to implement the fast-path task offload.
[0076] CD Appendix A contains a hardware description language (verilog code) description of an embodiment of a receive sequencer of a network interface device.
[0077] CD Appendix B contains microcode executable by a processor on the network interface device. The processor operates in conjunction with the receive sequencer of CD Appendix A.
[0078] CD Appendix C contains a device driver executable on the host as well as an ATCP stack executable on the host. The software of CD Appendix C operates in conjunction with the network interface device of CD Appendices A and B.
[0079] Although we have focused in this document and the accompanying drawings on teaching the preferred embodiment, other embodiments and modifications will become apparent to persons of ordinary skill in the art in view of this teaching. Therefore, this invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the specification and accompanying drawings.
Paper Appendix A /* *********************************************************************** * This file defines structures and constants used for communication * between a TCP driver and a miniport driver for an intelligent * network card for TCP fastpath offload. *********************************************************************** */ #if !defined( —— TCP_OFFLOAD —— H —— ) #define —— TCP_OFFLOAD —— H_ — /* * Definitions for types of MEDIA_SPECIFIC_INFO. These are intended * to not clash with the enum values defined in ndis.h * Eventually these should become public members of that enum. */ #define TCP_OFFLOAD_CHECKSUM_ID 0x1000 #define TCP_OFFLOAD_COMMAND_ID 0x1001 #define TCP_OFFLOAD_FRAME_ID 0x1002 /* * Structure passed as MEDIA_SPECIFIC_INFO carrying info about * checksum offload. * This may be replaced with the official NT5 method when * this becomes available. */ typedef struct _TCP_OFFLOAD_CHECKSUM { BOOLEAN DoIpChecksum; BOOLEAN DoTcpChecksum; ULONG HeaderLength; ULONG TcpLength; /* TCP payload size */ USHORT IpCsum; /* Debug verification only */ USHORT TcpCsum; /* Debug verification only */ } TCP_OFFLOAD_CHECKSUM, *PTCP_OFFLOAD_CHECKSUM; /* * In the current implementation we are doing physical address * translation of fastpath MDLs at the TCP driver level. * * Note that in other versions, such as those integrated with NT5, * we may simply pass the MDL address and have the * lower-level driver do the translation * * We need to be able to pass a TDI_SEND consisting of a * NETBIOS header plus 64K of data; the latter may not be * page aligned. * XXX this definition should really depend on PAGE_SIZE, * but for the moment we are on X86 where this is known to be 4K. */ #define TCP_OFFLOAD_MAXSG 20 /* * For outgoing data, we don't want individual DMAs for very * small buffer elements (in particular, note that the 4-byte netbios * header always appears in its own separate buffer), so we will * pass data elements of 4 bytes or less directly in the command. * We define a custom scatter/gather element to allow this. * XXX this could be compressed somewhat as a union, but would * be less legible... */ typedef struct _TCP_OFFLOAD_SG { ULONG Length; NDIS_PHYSICAL_ADDRESS PhysicalAddress; ULONG InlineLength; UCHAR InlineData[4]; } TCP_OFFLOAD_SG, *PTCP_OFFLOAD_SG; /* * Structure passed as MEDIA_SPECIFIC_INFO carrying info about * fastpath commands. */ typedef struct _TCP_OFFLOAD_COMMAND { ULONG CommandCode; /* Handout, Send, etc */ PVOID CommandContext; /* Identifies cmd at TCP level*/ ULONG HostContext; /* Host Context Handle */ ULONG LowerContext; /* Miniport context handle */ ULONG Status; /* On return */ union { struct _TCP_HANDOUTINFO { ULONG SrcIpAddr; /* Initial handout */ ULONG DstIpAddr; /* Initial handout */ USHORT SrcPort; /* Initial handout */ USHORT DstPort; /* Initial handout */ UCHAR MacAddr[6]; /* Generalize later */ } Handout; PVOID TcbAddr; /* 2nd-half handout */ struct _TCP_DATACOMMAND { ULONG WindowUpdate; /* May be 0 */ ULONG TotalLength; /* Send & Rev */ ULONG Resid; /* flush return */ ULONG Flags; ULONG NumAddrUnits; /* # S/G entries*/ TCP_OFFLOAD_SG AddrList[TCP_OFFLOAD_MAXSG]; } DataCommand; } command_u; } TCP_OFFLOAD_COMMAND, *PTCP_OFFLOAD_COMMAND; /* * Command codes */ #define TCP_OFFLOAD_HANDOUT1 0 #define TCP_OFFLOAD_HANDOUT2 1 #define TCP_OFFLOAD_SENDMDL 2 #define TCP_OFFLOAD_RCVMDL 3 #define TCP_OFFLOAD_WINUPDATE 4 #define TCP_OFFLOAD_FLUSH 5 #define TCP_OFFLOAD_CLOSE 6 /* * Status codes. */ #define TCP_OFFLOADCMD_SUCCESS 0 #define TCP_OFFLOADCMD_NOCONTEXT 1 #define TCP_OFFLOADCMD_STALECONTEXT 2 #define TCP_OFFLOADCMD_FLUSH 3 #define TCP_OFFLOADCMD_FAIL 4 /* * Data command flags. */ #define TCP_OFFLOAD_FORCEACK 1 /* Force ACK on RCV MDL completion */ /* * Structure passed as MEDIA_SPECIFIC_INFO carrying info about * fastpath input frames. */ typedef struct _TCP_OFFLOAD_FRAME { USHORT FrameType; /* Data, flush, etc */ USHORT Flags; /* PUSH etc */ ULONG HostContext; /* Fastpath connection cookie */ union { struct _FPDATAFRAME { ULONG AvailableLen; /* For indication */ PVOID Payload; /* Actual data */ USHORT PayloadLen; /* Length of this */ USHORT IpId; /* debug purposes */ } DataFrame; USHORT FlushReasonCode; /* For flush frames */ } frame_u; } TCP_OFFLOAD_FRAME, *PTCP_OFFLOAD_FRAME; /* * Frame types */ #define TCP_OFFLOAD_FRAME_INTERLOCK 0x0000 /* Handout handshake */ #define TCP_OFFLOAD_FRAME_DATA 0x0001 /* Data frame */ #define TCP_OFFLOAD_FRAME_FLUSH 0x0002 /* Flush frame */ /* * Frame flags; only 1 defined at present. */ #define TCP_OFFLOAD_FRAME_PUSHFLAG 0x0001 /* Rcv'd frame had PSH*/ /* * Definitions for the size of these various types of tcp offload * structures contained within a MEDIA_SPECIFIC_INFORMATION * structure (and therefore including the size of this up to * the ClassInformation[] field, since the TCP_OFFLOAD * structures are actually contained within the ClassInformation[] * array.) */ #define TCP_OFFLOAD_CHECKSUM_INFOSIZE \ (sizeof (TCP_OFFLOAD_CHECKSUM) + \ FIELD_OFFSET(MEDIA_SPECIFIC_INFORMATION, ClassInformation)) #define TCP_OFFLOAD_COMMAND_INFOSIZE \ (sizeof (TCP_OFFLOAD_COMMAND) + \ FIELD_OFFSET(MEDIA_SPECIFIC_INFORMATION, ClassInformation)) #define TCP_OFFLOAD_FRAME_INFOSIZE \ (sizeof (TCP_OFFLOAD_FRAME) + \ FIELD_OFFSET(MEDIA_SPECIFIC_INFORMATION, ClassInformation)) #endif /* —— TCP_OFFLOAD —— H —— */ | A host CPU runs a network protocol processing stack that provides instructions not only to process network messages but also to allocate processing of certain network messages to a specialized network communication device, offloading some of the most time consuming protocol processing from the host CPU to the network communication device. By allocating common and time consuming network processes to the device, while retaining the ability to handle less time intensive and more varied processing on the host stack, the network communication device can be relatively simple and cost effective. The host CPU, operating according to instructions from the stack, and the network communication device together determine whether and to what extent a given message is processed by the host CPU or by the network communication device. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to valves and particularly to a valve handle which can selectively lock the valve in open or closed positions with a locking slide.
Valves, and particularly ball valves, typically have stops for controlling the handle between fully open and fully closed positions while still allowing intermediate positions, if desired. In most applications, the valve is left in one of a fully open or fully closed position. In most installations, it is undesirable to inadvertently change the selected fully open or fully closed position. Prevention of inadvertent movement of the valve can be accomplished in a number of ways, including, for example, valve handle locks, such as disclosed in U.S. Pat. Nos. 5,427,135; 5,785,074; and D 358,455, in which locking rings or tabs are positioned to engage a valve handle and include apertures which permit a lock, such as a padlock, to be inserted between the locking member and the handle to prevent tampering with the valve when in a selected position. Allowed US Patent Publication No. 2015/0101684 entitled VALVE HANDLE LOCK, filed on Oct. 3, 2014, discloses yet another valve lock which provides the additional feature of allowing the valve to be held in a fixed position without locking or to prevent inadvertent motion of the valve. It also allows a padlock to be inserted to prevent tampering with the valve.
Some valves employed in connection with pipe systems carrying hot or cold fluids are insulated and, to accommodate the insulation, cylindrical extensions between the valve handle and the valve body are employed. An example of such a valve is a ball valve which has been sold for many years by NIBCO Inc. of Elkhart, Ind., under the trademark NIB-SEAL®. Due to the unique construction of such valves, they pose a significantly more difficult challenge in order to provide locking mechanisms without interfering with the insulated valve body and pipes to which the valves are connected.
SUMMARY OF THE INVENTION
The valve system of the present invention provides the ability to lock an insulated valve by providing a locking slide plate which extends in an axial direction parallel to and offset from the axis of the valve stem and selectively extends through a base plate mounted to the top of a valve to selectively engage stop tabs on the valve body. The locking slide plate also extends through the valve handle and through a locking member associated with the valve handle to selectively lock the valve in open or closed positions.
In a preferred embodiment, the locking slide plate has spaced-apart tines at its lower end which can selectively span the stop tabs on the valve body and includes a bias spring which urges the locking slide plate toward an unlocked position. In another embodiment, the locking slide plate comprises two sections which include a lower section having tines which selectively engage tabs on the valve body and a second upper section which is spring-biased to the lower section to float to allow the lower section to accommodate different diameter valve bodies and allow the upper section to lock to the locking member.
In each embodiment, a shoulder on the locking slide plate captively holds the locking slide plate between the valve body and handle. The locking slide plates of either embodiment include an aperture which aligns with an aperture in the locking member, which can be an upper valve plate attached to the valve handle, when the locking slide plate is depressed against the spring pressure to align the locking apertures, such that a lock can be inserted between the locking slide plate and the upper valve plate to lock the valve in a selected open or closed position.
Such a design, therefore, allows a valve which may be installed in an insulated environment and employs an extended handle for such purpose to be locked in open or closed positions, utilizing a minimum of parts and provides reliable operation in such an environment. These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partly in phantom form, of a first embodiment of a valve embodying the present invention, shown with the valve open and in an unlocked position;
FIG. 2 is a perspective view of the locking components of the valve shown in FIG. 1 ;
FIG. 3 is a perspective view of the valve shown in FIG. 1 , shown in the locked position with the valve open;
FIG. 4 is a perspective view of the top valve plate;
FIG. 5 is a perspective view of the base plate of the valve assembly;
FIG. 6 is a front elevational view of the locking slide plate incorporated in the valve shown in FIGS. 1-3 ;
FIG. 7 is a perspective view of an alternative embodiment of the valve shown, partly in phantom form and in a locked valve open position;
FIG. 8 is a perspective view of the valve body and the locking mechanism associated with the valve body;
FIG. 9 is a perspective view of the components of the compound locking slide plate shown in FIG. 7 ;
FIG. 10 is a perspective view of the components shown in FIG. 9 during the assembly process;
FIG. 11 is a perspective view of the components of the locking slide plate shown assembled;
FIG. 12 is a perspective view of the valve assembly, shown in an unlocked valve open position;
FIG. 13 is a perspective view of the valve of FIG. 12 shown in an unlocked valve closed position; and
FIG. 14 is a perspective view of the valve shown in FIG. 7 , but shown in a locked closed valve position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1 , there is shown a valve installation for a hot or cold fluid system which includes a valve assembly 10 which, in the embodiment shown, is a ball-type valve having a valve body 12 . The ball valve can be of generally conventional construction, including a ball 54 ( FIGS. 12-14 ) with a valve seat 50 and a passageway 51 . The ball rotates within the body of the valve 12 between open and closed positions to allow or stop the flow of fluid through the valve. Extending upwardly from the valve body is a valve stem 14 which is keyed to an aperture 21 ( FIG. 5 ) in a valve base plate 20 and secured thereto by a lock nut 15 . Valve body 12 includes a pair of orthogonally aligned tabs 16 and 18 which align with the locking mechanism of the present invention to selectively lock the valve in an open position, as seen in FIG. 1 , or rotated 90° to align with tab 18 to selectively lock the valve in a closed position. The valve assembly includes a handle 11 with a cylindrical extension 13 which engages the base plate to rotate the ball 54 . Extension 13 also positions the handle 11 in spaced relationship to the valve body 12 .
In environments where the valve assembly 10 is employed with hot or cold fluids, such as in an HVAC system, the cylindrical extension 13 extends between valve handle 11 and base plate 20 to which the extension is fixedly secured by interlocking tabs on member 13 and slots 22 on plate 20 and fastening screws 29 . A floating cylindrical sleeve 17 typically surrounds the valve handle extension 13 to provide an interface between fixed insulation 25 surrounding the valve and the movable valve handle 11 and extension 13 . This allows the valve handle to move without disturbing the surrounding insulation 25 . An cap 27 fills the cylindrical extension 13 of the valve handle and has suitable apertures allowing for freedom of movement of the locking assembly described below. The body of the ball valve can include any type of interconnection with fluid conduits (not shown) including, for example, threaded socket 19 at each end of the valve, as illustrated in FIG. 1 .
The handle 11 of the valve assembly 10 can be locked in open or closed positions by the unique locking system now described in detail in connection with FIGS. 2-6 . The locking assembly 30 includes a locking slide plate 32 which, as seen in FIG. 6 , includes a pair of spaced-apart tines 34 and 36 which extend through slots 24 and 26 , respectively, in the base plate 20 and over one of the locking tabs 16 or 18 of the valve body 12 , as seen, for example, in FIG. 3 , when the valve is in a locked open position and the locking slide plate 32 is lowered. Locking slide plate 32 is biased to an unlocked position, as seen in FIGS. 1 and 2 , by a spring 35 which extends over a post 23 extending upwardly from the base plate 20 to position the lower end of spring 35 with respect to the base plate. The upper end of spring 35 surrounds and is captively held by a tab 33 centered in the slot 37 between tines 34 and 36 . The locking slide plate 32 includes a pair of shoulders 38 with an upwardly extending leg 39 including an aperture 31 for receiving a lock when it is desired to lock the valve in an open or closed position. The shoulders 38 captively hold locking slide plate 32 in the valve body by engaging the underside of top plate 40 adjacent slot 44 ( FIG. 4 ). The spring 35 , as seen in FIG. 2 , urges the locking slide plate 32 toward an unlocked position with leg 39 extending through a top valve plate 40 . Plate 40 is secured to the top surface of valve handle 11 , as illustrated in FIG. 1 by means of a plurality of fasteners 41 at the corners of the outwardly extending mounting tabs 43 of valve plate 40 . The valve plate 40 defines a locking member associated with the valve handle. The valve handle may, however, integrally include the structure of valve plate 40 to achieve the locking valve assembly of this invention.
The top valve plate 40 , as best seen in FIG. 4 , includes a slot 44 through which the leg 39 of locking slide plate 32 extends and through an upwardly extending formed locking box 45 consisting of legs 46 and 47 , an upper wall 48 with a slot 49 aligned with slot 44 . The legs 46 and 47 each include an aperture 42 which aligns with aperture 31 in the locking slide plate when it is pushed downwardly against bias spring 35 , as shown in FIG. 3 . In this position, the tines 34 and 36 surround the locking tab 16 (shown in the valve locked open position). The aperture 31 and locking slide plate align with the apertures 42 in the top valve plate 40 to allow a lock, such as a padlock 28 (shown schematically in FIG. 3 ), to be positioned through the aligned apertures for locking the valve in position.
In operation, the locking slide plate 32 normally is biased to an unlocked position, as shown in FIGS. 1 and 2 , by spring 35 , such that the tines 34 and 36 do not extend below the slots 24 and 26 of plate 20 and, therefore, allow the handle 11 to be rotated from the open position aligned with tab 16 to a 90° rotated closed position whereby the tines 34 and 36 would be aligned with tab 18 . In either position, the end of leg 39 can be pressed downwardly against the bias spring 35 and the lock inserted through apertures 31 in the locking slide plate 32 and apertures 42 in the top plate 40 for locking the valve in a selected open or closed position. This embodiment works well for a given diameter of the valve body 12 and the length of locking slide plate 32 can be selected to accommodate different valve body diameters.
A universal compound locking slide plate, however, is disclosed in the second embodiment, which is independent of the diameter of valve bodies and now described in connection with FIGS. 7-14 . In the alternative embodiment illustrated in FIGS. 7-14 , the same part numbers used for the first embodiment of FIGS. 1-6 are employed for the valve body, valve handle, extension, and the top plate. The primary difference is the use of a compound locking mechanism 130 including two separate sliding plates 140 and 150 and two bias springs 145 , 170 as compared to the first embodiment.
The valve assembly 110 shown in FIG. 7 includes the same handle 11 as in the first embodiment, and a similar top plate 30 attached to the upper surface of valve handle 11 by fasteners 41 . The only difference in the top plate 30 is that it is formed with U-shaped upward legs 46 and 47 , each having an aperture 42 aligned with one another for receiving the lock (such as lock 28 of FIG. 3 ) between the top valve plate 40 and the locking mechanism now described.
The locking mechanism 130 is best seen in FIG. 8 and includes a lower locking slide plate 140 and an upper locking slide plate 150 , which are interconnected to one another, as illustrated in the assembly views of FIGS. 9-11 . The upper slide plate 150 and lower slide plate 140 are generally rectangular plates with plate 150 extending through slot 44 in top plate 40 , as seen in FIG. 7 . Plate 150 includes an aperture 152 which aligns with apertures 42 of the top plate 40 , such that the sliding locking mechanism 130 can be locked into a locking position, as shown in FIGS. 7 and 8 . Slide plate 150 includes a rectangular opening 154 at an end opposite the locking aperture 152 and includes orthogonally angled pairs of spaced tines 156 and 158 which guidably support slide plate 150 in its sliding movement with respect to the lower slide plate 140 . Adjacent opening 154 is a tab 155 which aligns with and engages the upper end of spring 170 between plates 140 and 150 , as best seen in FIG. 11 .
The lower slide plate 140 includes a pair of tines 144 and 146 which span the locking tabs 16 and 18 of valve body 12 when in a lowered locked position. A second bias spring 145 urges the lower locking slide plate 140 (and the connected upper slide plate 150 ) away from the locking position. Spring 145 is captively held in slot 143 between tines 144 and 146 and fits over tab 147 at the upper end of slot 143 . The lower end of spring 145 is captively held by the upwardly extending pin 23 in base plate 20 , as seen in FIG. 7 . Slide plate 140 includes an inverted L-shaped slot 142 which receives the tines 156 and 158 on the end of slide plate 150 , as seen in FIGS. 10 and 11 , with the tines 156 , 158 sliding on opposite sides of plate 140 along the vertical section 141 of slot 142 . Spring 170 is captively held to the upper end of plate 140 by a tab 148 at the lower end of slot 142 and spring 170 and by inwardly projecting shoulders 149 at the top of slot 142 and spring 170 . When sliding plates 140 and 150 are assembled as seen in FIGS. 7, 8, and 11 , tab 155 of the sliding plate extends into and engages the upper end of spring 170 . When connected, plates 140 and 150 define a compressible compound locking slide mechanism 130 . The spring constant of spring 170 is selected to be slightly greater (i.e., a stiffer spring) than the bias spring 145 , such that depression of the upper locking slide plate 150 will force the lower slide plate 140 into a locking position surrounding one of the tabs 16 or 18 of the valve.
Normally, when unlocked, the upper slide plate 150 is in the position as illustrated in FIG. 12 (with the valve in an open position) or FIG. 14 (with the valve in a closed position). When, however, it is desired to lock the valve in either of those positions, pressing downwardly on a single slide member may not allow the aperture, such as aperture 31 the first embodiment, to extend downwardly sufficiently to align with the mating apertures in the top valve plate. In order to compensate for variations in the distance between base plate 20 and the valve body 12 , the embodiment of the slide members of FIGS. 7-14 is employed. With the embodiment shown in FIGS. 7-14 , however, the upper plate 150 can slide along slot 142 and compress spring 170 once tines 144 and 146 bottom out on base valve body 12 . This allows the upper plate 150 to move downwardly an additional distance defined by the length of the vertically extending leg 141 of slot 142 to align lock-receiving apertures 42 and 152 and accommodate different diameter valve bodies. This, in effect, provides a compressible locking slide 150 . FIGS. 12 and 13 show the valve in an unlocked open position and an unlocked closed position, respectively. FIGS. 7 and 8 , on the other hand, show the locking assembly 130 and the valve in an open locked position. FIG. 14 shows the valve in a closed locked position.
It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims. | A valve system includes a spring-biased locking slide plate which extends in an axial direction parallel to and offset from the axis of the valve stem and selectively extends through a base plate mounted to the top of a valve to selectively engage stop tabs on the valve body. The locking slide plate also extends through the valve handle and through a locking member to selectively lock the valve in open or closed positions. In one embodiment, the locking slide plate comprises two sections which include a lower section having tines which selectively engage tabs on the valve body and a second upper section which is spring-biased to the lower section to float to allow the lower section to accommodate different diameter valve bodies. | 5 |
This application is a continuation-in-part of application Ser. No. 755,257, filed July 15, 1985 and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to modulated frequency synthesizers, and more particularly to an improved method and arrangement for modulating phase-locked loop frequency synthesizers. This arrangement can accommodate voice signals as well as digital data or low frequency tone modulation and can produce high deviation, FM (frequency modulated) signals with very low distortion, while exhibiting a flat, wide, modulation bandwidth that is independent of the phase-locked loop bandwidth.
Today's communications systems require efficient use of the crowded radio spectrum, especially in congested metropolitan areas. To achieve efficient use of this limited congested spectrum, modern communications systems use elaborate data and tone-coded signalling schemes, such as Private Line (PL) and Digital Private Line (DPL) available in radios from Motorola, Inc., which force greater performance from the overall transmitter design. That is, they are expected to be able to utilize the available modulation bandwidth down to nearly DC, (or at least to under 1 Hz), as well as beyond voice frequencies. In addition, such transmitters are expected to maintain their carrier frequency with high stability and yet offer fast lock time and wide deviation capability with very low distortion, all of which have an impact on the manner in which the transmitter can be modulated. The above problems are exacerbated when attempting to design a transmitter for a relatively low radio frequency (RF) carrier, since there are few schemes for achieving relatively large percentage deviations of the RF carrier, and there are even fewer schemes which achieve the needed deviation with low distortion.
In any event, certain general techniques have been developed which address two of the three constraints by providing the desired carrier frequency stability and generally utilize a high stability unmodulated reference oscillator in conjunction with a phase-locked loop frequency synthesizer. Because these phase-locked loop arrangements generally include a frequency divider in the loop feedback path, they provide a way in which to effect wide output deviation.
One known improvement utilizing dual port modulation of a frequency synthesizer loop simultaneously applies modulation to both the input of a voltage controlled oscillator (VCO) and through a summing network to the output of a phase detector such that a cancellation of the two signals occurs without disrupting the error voltage normally outputted from the phase detector. This achieves wide deviation capability for a modulating signal while maintaining a high degree of frequency stability. Although such an arrangement achieves cancellation of the modulation components in the error voltage sent to the VCO and is suitable for some system designs, it nevertheless suffers from two serious drawbacks.
The first disadvantage is that any gain variations with temperature (especially for the phase detector) will adversely affect the modulation sensitivity. Moreover, if high modulation sensitivities are used, any variation in gain can be significant. This is because it is difficult to balance the two modulation ports when wide bandwidths are needed. What is meant by "balance" is that the designer insures that each modulation port individually provides the same magnitude of deviation sensitivity, or peak frequency deviation per volts of modulation signal, and further, that each modulation port individually causes the same direction of deviation (positive or negative) in order to effect cancellation in the phase detector.
A second disadvantage of such an arrangement involves the time relationship of the two modulation components so induced. That is, the inputted reference modulation must be delayed in a suitable delay network so that it is maintained in phase synchronism with the VCO modulation components, in order to insure that complete cancellation occurs at the output of the summing network. A possible embodiment for this delay network is a sample and hold network. Without such a delay network, the frequency synthesizer will suffer degradation to data modulation, especially when relatively fast data rates are utilized. There will also be additional spurious output sidebands generated when attempting to utilize fast data rates without the benefit of such a suitable delay network. This correspondingly greater spurious output requires additional attenuation in the loop filter to prevent degrading the synthesizer's spurious output performance still further. But this forces the response time of the loop to be even slower.
A second known arrangement utilizes a slightly different scheme of dual port modulation for a frequency synthesizer by feeding the modulating signal in at the VCO and ahead of the phase detector, but is deficient in that it does not utilize the full modulation bandwidth that theoretically is available. Such a capability, especially at low modulating frequencies, is needed to make better use of the limited resources of frequency bands and modulation bandwidths dictated by ever-narrower channel bandwidths available for land mobile applications. This second known arrangement is only able to work effectively down to 500 Hz with 1.5% distortion, and down to 300 Hz with 5% distortion. Thus, utilizing such an arrangement wastes nearly 500 Hz of precious modulation bandwidth due to the unacceptably high distortion that results. Each of the disadvantages listed above leads to serious compromises in frequency synthesizer system performance, all of which are undesirable and wasteful.
Accordingly, there exists a need for an improved frequency modulation arrangement for a phase-locked loop frequency synthesizer which is able to accommodate voice signals as well as digital data or low frequency tone modulation with very low distortion, such that it can produce high deviation, FM signals while exhibiting a flat, wide, modulation bandwidth, down to approximately 1 Hz (and thus nearly equal to the theoretical maximum bandwidth). There exists a further need to provide the above mentioned capability in a transmitter having a low frequency RF carrier.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved, frequency modulation arrangement for a phase-locked loop frequency synthesizer having high stability such that it has a wide deviation capability which is nearly equal to the theoretical maximum modulation bandwidth.
It is a further object of the present invention to provide an improved frequency modulation arrangement for a phase-locked loop frequency synthesizer of the foregoing type such that it has wide deviation capability and very low distortion so that the modulation bandwidth is nearly equal to the theoretical maximum bandwidth.
It is a further object of the present invention to provide an improved frequency modulation arrangement of the foregoing type which is essential for use in a transmitter having a low frequency RF carrier, and requiring a relatively large percentage deviation capability.
It is a further object of the present invention to provide an improved serrasoid phase modulator which, when utilized with an integrator, permits low frequency modulating signals of less than 1 Hz to effect low distortion FM, so as to nearly equal the low frequency, low distortion performance characteristics of a direct-FM modulated VCO.
In practicing one form of the invention, a particular frequency modulator arrangement is added to modulate the signal coming from an included high stability unmodulated reference oscillator within a phase-locked loop frequency synthesizer. With this frequency modulator cooperating with the modulated VCO, wide deviation over the full modulation bandwidth is possible. The wide deviation capability arises from the multiplication effect of modulating the signal occurring at the divided-down frequency outputted by the selectable-integer loop divider. Thus, the modulation information is injected at two separate ports within the phase-locked loop frequency synthesizer. The first port is at the input of the VCO, while the second port feeds a frequency modulator consisting of a particular improved form of serrasoid phase modulator interposed between the output of the fixed divider and the reference signal input of the phase detector. A serrasoid phase modulator is one which creates a sawtooth output waveform in which the modulating signal affects the time occurrences of zero crossings on either the rising or falling edges of the inputted reference signal. In the present invention, it also includes a comparator on the output to permit a square waveform to be generated. Furthermore, by placing an integrator network ahead of the serrasoid phase modulator, frequency modulation is effected. As will be seen, the present invention accomplishes frequency modulation of the reference signal by modulating the critical, or rising, edge of the output of the reference divider before it is applied to the phase detector. Prior phase modulators were only able to accomplish 1.5% distortion at 500 Hz, degrading to 5% distortion at 300 Hz. By contrast, the phase modulator according to the present invention is able to handle a wide range of modulating signals, including tones as low as 1 Hz, through normal voice frequencies, to relatively high digital data frequencies, with relatively low distortion. The present invention has measured performance which exhibits less than 0.2% distortion at 30 Hz with 8 KHz of deviation (4 KHz peak deviation). This distortion measurement is usually conducted according to EIA standards which measure the desired signal in the presence of noise and distortion (SINAD). The modulation information inputted to the phase modulator is, of course, integrated in order to produce frequency modulation of the reference signal. The other port accomplishes direct FM of the VCO in a manner (or polarity) the same as that induced by the reference modulator so that the modulated output signal fed back through the loop divider nulls, or cancels, with the modulated reference signal within the phase detector of the phase-locked loop. Thus it should be evident that the goal is to make the phase modulator capable of nearly the same performance as that of the direct-FM VCO, especially with regard to noise and distortion at low frequencies.
An alternate form of phase-locked loop employing the present invention utilizes the frequency modulator in the feedback path between the loop divider and the phase detector (in conjunction with a phase inverter) to achieve cancellation of the modulation components before they reach the phase detector. Each of these two port modulation systems has a widened usable bandwidth resulting from the improved distortion characteristics of the serrasoid phase modulator, while still exhibiting an essentially flat modulation frequency response as well as the widened deviation capability given by the factor N of the loop divider. Moreover, the modulation bandwidths may be set independently of the loop bandwidth.
These and other objects of the present invention will become apparent to those skilled in the art upon consideration of the accompanying specification, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to the drawings, wherein like reference numerals indicate like elements in the several figures and in which:
FIG. 1 is a block diagram of a frequency modulator arrangement for a frequency synthesizer according to the known art.
FIG. 2 is a more detailed block diagram of a frequency modulator arrangement for a frequency synthesizer according to the known art having an included fixed divider in the reference frequency chain before the phase detector.
FIG. 3 is a functional representation of a typical serrasoid phase modulator according to the known art.
FIG. 4 is a block diagram of a frequency modulator arrangement for a frequency synthesizer according to the present invention.
FIG. 5 is an illustration of the modulation spectral bandwidths resulting when attempting to transmit baseband information (a) according to the teachings of the prior art (b), in contrast to the teachings of the present invention (c).
FIG. 6a is a schematic diagram of the improved frequency modulator according to the present invention.
FIG. 6b illustrates signal diagrams showing the function of the improved frequency modulator as represented in FIG. 6a.
FIG. 7 is a preferred embodiment of a phase-locked loop frequency synthesizer employing the improved serrasoid phase modulator of the present invention and including an offset for generating relatively large percentage deviation FM signals at a relatively low frequency RF carrier.
FIG. 8 is a configuration similar to FIG. 4 for a phase-locked loop frequency synthesizer except that it utilizes a modulation phase inverter in conjunction with the improved serrasoid phase modulator in the feedback path between the loop divider and the phase detector.
DETAILED DESCRIPTION
Referring now to the drawings, a basic phase-locked loop (or PLL) frequency synthesizer arrangement 10 is shown in FIG. 1 which includes a two-port modulation capability, according to the known art. This PLL synthesizer arrangement exhibits a single output frequency and consists of a reference source 12, a frequency modulator 14, a phase detector 16, a voltage controlled oscillator (or VCO) 18 having an output 20, a portion of which is fed back to phase detector 16. The modulating signal enters at 22 and is fed to each of the two ports, 24 and 26, so as to modulate the frequency of output 20. Intervening stage 25 provides gain and frequency shape adjustment. Thus, by using this two-port modulation arrangement on a PLL frequency synthesizer, cancellation of the two modulating signals at the output of phase detector 16 results for a single output frequency.
A more useful embodiment of a modulated PLL frequency synthesizer arrangement is depicted at 30 that provides a number of different output frequencies such as are needed in multi-channel transmitter or transceiver, as shown in FIG. 2. Like numerals are employed for corresponding components wherever applicable. In this embodiment, the PLL consists of a reference source 12, a frequency modulator 14, a phase detector 16, and a VCO 18 having an output 20, as shown. Here, reference source 12 includes reference oscillator 32 and fixed-integer frequency divider 34. Frequency modulator 14 includes phase modulator 36 with integrator 38 at the frequency modulator input port 24. Between phase detector 16 and VCO 18, is loop filter 40, as shown. Connected in the output feedback path from VCO 18 back to phase detector 16 is selectable-integer frequency divider 42, as shown. This arrangement utilizes the multiplicative effect of variable-integer frequency divider 42 as well as cancellation of the modulating signals within phase detector 16 to achieve wide deviation with low distortion at output 20 for modulating frequencies between 300 Hertz (Hz) and 4 KHz, or voice frequencies. Arrangement 30 of FIG. 2 allows the modulation signal bandwidth to be set independently of the requirement for the loop bandwidth, which is controlled by means of loop filter 40. More particularly, phase use of loop divider 42 provides the capability of magnifying the effective deviation by the divider variable "N", since the loop attempts to maintain a constant error signal by cancellation of the modulating signals at the output of phase detector 16.
FIG. 3 depicts a basic diagram of a typical phase modulator 36, according to the known art, which is of the serrasoid type. A switch 44, acted upon by a combination of signals, including reference frequency f r , creates a pulse stream at the periodic rate of f r having a voltage ramp on the critical, or rising, edge due to current source 46 and capacitor storage element 48. This pulse stream signal is compared with the value of the modulation signal 50 (plus a DC bias voltage 52) in connection with comparator 54. The output of comparator 54 clears D-type latch 55a which has inverter 55b connected to its clock input. The output of D-type latch 55a produces V' which represents the resultant modulated reference signal f r ' at output 56. According to the known art, serrasoid modulator 36 modulates the trip voltage of comparator 54 such that the critical or rising edge of the output waveform at 56 shifts.
A two-port modulation arrangement employing the present invention is shown at 30' in FIG. 4. As shown, it includes a reference source 12, a modified frequency modulator 14', a VCO 18 having an output 20, a modulation input 22 feeding two ports, 24 and 26, with port 26 including an additional signal adjustment stage 25 as shown. Here, the modified frequency modulator 14' includes a particular serrasoid phase modulator 60, with a modified integrator 38', as shown. The PLL also includes loop filter 40, and selectable-integer frequency divider 42. The benefits of using such an arrangement as depicted in FIG. 4 are shown in the simplified frequency domain diagrams depicted in FIG. 5. FIG. 5a shows the frequency spectrum of the input modulation which is necessary in today's modern systems employing low frequency tones, such as Private Line or Digital Private Line frequencies, and digital data, in addition to voice frequencies. FIG. 5b depicts the capability of the known modulated frequency synthesizer arrangement depicted in FIG. 2 according to the known art. FIG. 5c depicts the modulation input handling capability for the frequency modulated PLL synthesizer according to the present invention. It should be noted in FIG. 5c that the low frequency tones, represented by PL and DPL, and the digital data are able to be transmitted as well as the voice frequencies. The full frequency modulating bandwidth capability depicted in FIG. 5c approaches and nearly equals the theoretical maximum bandwidth for frequency modulated transmitters and is brought about by the improved frequency modulator 14' represented in FIG. 4.
The details of improved frequency modulator 14' are given in FIG. 6a, as shown. The integrator 38' and the improved serrasoid phase modulator 60 are shown within dashed lines. The phase modulator includes an input 55c' for the reference frequency f r from divider 34. It is applied to an electronic switch comprised of transistor 62a and 62b, having an input resistive divider 64a and 64b, and includes a supply resistor 66, as shown. Connected to electronic switch transistor 62b is capacitive storage element 48', which is fed from a passive current source having a filter section composed of resistor 68 and capacitor 70, which in turn feeds current-limiting resistor 72, as shown. Resistor 72 is chosen to be approximately one order magnitude larger than resistor 68. The node which joins resistor 72 with transistor 62b and capacitive storage element 48' make up one input to a comparator consisting of transistor 74a and 74b fed from a common emitter resistor 76 as shown. The output is taken from 56', which represents f R ' fed to the phase detector. Resistive divider 78, 80, provides the bias voltage for transistor 74b as well as the second input point for the comparator to which the integrator 38' connects. Integrator 38' consists of resistor 82 and capacitor 84 connected as shown with a DC blocking capacitor 86. The modulation input is provided at terminal 50'. Upon further consideration of improved serrasoid phase modulator 60 it is evident that the components make up a voltage ramp generator utilizing the passive current source, the capacitive storage element 48', and the transistor switch 62a and 62b. If an active, or transistor, current source were used, a certain amount of shot noise would be included and would influence the voltage on capacitive element 48'. Assuming a DC current source having constant current value I with noise current i N and assuming a given ramp slope, as the voltage on capacitor 48' passes through the threshold voltage associated with comparator, the amount of time jitter is proportional to i N /I. Since the transistor current source is dominated by shot noise,
i.sub.N.sup.2 =2qI,
i.sub.N =(2qI).sup.1/2,
and therefore
i.sub.N /I=(2q/I).sup.1/2. (1)
For the circuit as depicted at 60 in FIG. 6a, the noise associated with the resistive passive current source is related to:
v.sub.N.sup.2 =4KTR,
then
i.sub.N =v.sub.N /R=2(KT/R).sup.1/2.
Since the DC current I is given by:
I=(V.sub.r -V.sub.x)/R,
as the voltage on capacitive element 48' passes through the threshold voltage V x , the value of noise associated with the passive current source is given by: ##EQU1## which equals ##EQU2## Then, for example, if: I=300 microamps,
V x =3 volts, and
V c =9 volts, then
R=6 volts/300 microamps=20K ohms,
and the shot noise associated with an active current source would result, according to equation (1), in a value of:
i.sub.N /I=3.27×10.sup.-8 amperes/√Hertz,
whereas a passive current source associated with using a resistor results, according to equation (2), in a value of:
i.sub.N /I=3.03×10.sup.-9 amperes/√Hertz.
Thus, the passive current source should give more than 20 dB improvement over an active current source. In the above equations,
q=1.6×10 -19 coulomb, or electronic charge,
K=1.38×10 -23 joule/degree Kelvin, (or Boltzman's constant), and
T=300 degrees Kelvin, in absolute temperature.
In the preferred embodiment of the improved frequency modulator 60 of the present invention, typical values for the passive current source, including the filter section with a corner frequency of less than 1 Hz, include:
Resistor 68=2.2K ohms,
Capacitor 70=10 microfarads, and
Resistor 72=20K ohms.
The capacitive storage element 48'=0.0015 microfarads. The values for integrator 38' include:
Resistor 82=0-200K ohms, for setting gain, and
Capacitor 84=22 microfarads.
FIG. 6b depicts four waveforms representing the input signal f r , the ramp voltage V c (t) on the capacitive element 48', V 1 (t) representing the variable trip voltage of the comparator caused by the modulation about a fixed bias voltage V x established by resistors 78 and 80, and finally the output signal F r ' depicting movable rising, or critical, edge of the output waveform available at output 56'.
FIG. 7 depicts at 90 another arrangement for a frequency modulated PLL synthesizer apparatus embodying the present invention. This arrangement is especially for lower frequency ranges requiring proportionally larger deviation with low distortion. As will be noted, it is similar to the PLL synthesizer depicted in FIG. 4, but takes the reference oscillator signal at 92, passes it through a multiplier 94 to the injection port 96 of an offset mixer 98 in order to offset or down-mix the modulated signal 20, which typically has less than 0.2 percent distortion at a modulating frequency of 30 Hz with 8 KHz deviation (4 KHz peak deviation) at 150-170 MHz, down to a lower frequency at output 100, while maintaining the same amount of deviation with low distortion at 30-50 MHz. Here, the fixed reference frequency divider 34 has a divisor of 2880, and multiplier 94 has a factor of 8. The circuit arrangement of FIG. 7 fulfills a long-felt need to achieve very wide deviation for very low modulating frequencies for a very low frequency range RF carrier. In this instance, where a Digital Private Line signal is needed to be transmitted in addition to voice signals, it is possible to determine the maximum peak deviation required for the DPL waveform which has a maximum length of time in either the zero or one state equal to about 44 milliseconds. Since the peak phase deviation is equal to the time integral of the peak frequency deviation integrated over a time interval, it is possible by known techniques to determine that for 750 Hertz of peak frequency deviation, one needs to be able to achieve 207 radians of peak phase deviation. This is a stark contrast to voice modulation which requires a orse case beta=5000/300, or 16.7 radians, which is quite a bit less. To illustrate the value of the new phase modulator, it is instructive to consider previous techniques for implementing phase modulators. Perhaps the most common type of phase modulators are the varactor/LC type. Unfortunately, it is not practical to implement one at 5-10 KHz. However, even when considering a 3 section varactor/LC tuned phase modulator, it is only able to achieve about 130 degrees or 2.27 radians of phase deviation with reasonable linearity. The disclosed improved phase modulator 60 incorporated within the improved frequency modulator 14' is able to achieve the large phase (or frequency) peak deviation required for a reference center frequency in the region of 5 KHz to make the above PLL frequency synthesizer arrangements possible. Moreover, the improved low frequency, low noise, and high deviation performance of this improved phase modulator is a key element of the present invention.
Finally, an alternate embodiment of a modulated PLL frequency synthesizer apparatus embodying the present invention is depicted at 110 FIG. 8. As will be noted, it is similar to the PLL synthesizer arrangement depicted in FIG. 4, but instead utilizes the improved frequency modulator consisting of low-noise serrasoid phase modulator 60 and integrator 14' with a phase inverter 112 to achieve cancellation of the modulation components in the feedback loop signal 114 before inputting this feedback signal to phase detector 16. The frequency modulated RF carrier output frequency occurs at output 116.
In summary, each of the above-mentioned arrangements 30', 90, and 110 is able to accomplish the frequency modulation of the PLL without losing gain balance between the two ports 24, 26 caused by variations in phase detector gain, and without the need for a delay network for maintaining proper phase synchronization of the modulated reference and modulated VCO signal components. Moreover, each of the above-mentioned arrangements 30', 90, and 110 is able to utilize the full modulation bandwidth down to less than 1 Hz and nearly approach the maximum available modulation bandwidth available by such an arrangement. Each of the above-mentioned arrangements exhibits an essentially flat, wide, modulation bandwidth that is independent of the PLL bandwidth. And, in particular, arrangement 90 is able to achieve full modulation bandwidth capabilities for very wide percentage deviation encompassing low frequency tones, digital data, as well as voice band signals for a transmitter operating with a relatively low frequency range RF carrier. Thus, each of the above arrangements, as well as the improved frequency modulator depicted in FIG. 6a, is able to overcome the limitations of the known prior art.
Although the several two-port synthesizer modulation arrangements of the present invention fully disclose many of the attendant advantages, it is understood that various changes and modifications not depicted herein are apparent to those skilled in the art. Therefore, even though the form of the above-described invention is merely a preferred or exemplary embodiment given with practical alternates, further variations may be made in the form, construction, and arrangement of the parts without departing from the scope of the above invention. | An improved frequency modulator apparatus for use in phase-locked loop (PLL) frequency synthesizers is disclosed which makes possible high deviation, low distortion, FM signals for a wide range of modulating signals, such as digital data or low frequency tone modulation. In a first embodiment having the improved frequency modulator, this apparatus advantageously injects the modulation signal into two ports, one at the VCO and the other provided in an unmodulated reference source signal chain. By properly balancing the levels into each of these two ports, a cancellation effect occurs which nulls the modulation signal at the output of the phase detector. In a second embodiment, the improved frequency modulator is incorporated in a PLL frequency synthesizer with an offset mixer to achieve relatively wide percentage deviation at a low frequency RF carrier. In a third embodiment, the improved frequency modulator is incorporated in a PLL synthesizer in its feedback loop so as to cancel the modulation components before they reach the phase detector. Thus, in the first two embodiments, the added phase modulator is inserted in the reference source signal path to the phase detector, while in the alternate third embodiment, the phase modulator is inserted into the feedback path and includes a phase inverter stage to correct for the inherent modulation polarity reversal. | 7 |
CLAIM FOR PRIORITY
[0001] This application claims the benefit and priority of U.S. Provisional Patent Application Ser. No. 61/348,011 filed May 25, 2010 which is incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] Human fingernails are made up of layers of keratin—a protein that's also found in both hair and skin. Each nail is comprised of several parts.
[0003] The structure known as the fingernail is divided into six specific parts—the root, nail bed, nail plate, eponychium (cuticle), perionychium, and hyponychium.
[0004] Each of these structures has a specific function, and if disrupted can result in an abnormal appearing fingernail.
[0005] The root of the fingernail is also known as the germinal matrix. This portion of the nail is actually beneath the skin behind the fingernail and extends several millimeters into the finger itself. The fingernail root produces most of the volume of the nail and the nail bed. This portion of the nail does not have any melanocytes, or melanin producing
[0006] The nail plate is the actual fingernail, made of translucent keratin. The pink appearance of the nail comes from the blood vessels underneath the nail. The underneath surface of the nail plate has grooves along the length of the nail that help anchor it to the nail bed.
[0007] Nail folds are the skin that frames each of the fingernails on three sides.
[0008] A nail bed is the skin beneath the nail plate.
[0009] The cuticle of the fingernail is also called the eponychium. The cuticle is situated between the skin of the finger and the nail plate fusing these structures together and providing a waterproof barrier. Cuticle tissue overlaps the nail plate at the base of the nail.
[0010] The lunula is the whitish, half-moon shape at the base of your nail.
[0011] The perioncyhium is the skin that overlies the nail plate on its sides. It is also known as the paronychial edge. The perionychium is the site of hangnails, ingrown nails, and an infection of the skin called paronychia.
[0012] The hyponychium is the area between the nail plate and the fingertip. It is the junction between the free edge of the nail and the skin of the fingertip, also providing a waterproof barrier.
[0013] Cracks, chips, or other surface anomalies are often viewed unfavorably.
[0014] Fingernail polish is a lacquer or other coating applied to toenails and fingernails for appearance, but also as nail protection.
[0015] The present invention is a composition for repairing the various anatomical parts of a fingernail and repairing cracks or chips in fingernail polish.
[0016] Nail polish consists of a pigment and a flowable resin material. The nail polish is painted on a surface of a nail using a brush and when allowed to dry, the pigment becomes embedded in the resin.
[0017] Incoming light, typically light of a broad wavelength spectrum such as daylight, contacts the surface of the dried polish, and is partially transmitted into the polish and partially reflected. The wavelengths of light that are transmitted into the polish are selectively absorbed or reflected by the pigment, to a large degree, and the resin to a smaller degree. The wavelengths not absorbed by the pigment material are reflected and perceived as that color by the eye. The nail polish has an index of refraction, based on the components, including at least the pigment and resin material of the nail polish.
[0018] When a nail, having nail polish previously applied, becomes “chipped”, a section of the nail polish on a nail is partially or completely dislodged from the surface of the nail resulting in a “chip”. The chipped section likely will be seen by an observer, as a defect in the polished nail.
[0019] Preferably, the chipped surface is repainted with nail polish of like pigment color to match the nail polish remaining on the surface. This becomes inconvenient when the applied color of polish is unavailable, or not readily available e.g. is at home and not in the user's possession.
BRIEF SUMMARY OF THE INVENTION
[0020] The present invention is a composition and method to repair fingernail and toenail anomalies. An anomaly, as used herein, refers to cracks, crevices, holes, and the like in any part of the nail surface. Additionally, an anomaly, as used herein can refer to any crack, crevice, or hole in a coating applied to the nail. Coatings, as known in the art, encompass many materials and include, but limited to polishes, acrylics, combinations thereof, and the like. The composition is a carrier and reflective material that, when applied to a fingernail or toenail anomaly, fills said anomaly and reflects a color that is the same color of the nearby coating color, thereby reducing or eliminating the visual presence of the anomaly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of a portion of the end of a finger and a fingernail.
[0022] FIG. 2 is cross section from section lines A-A in FIG. 1 .
[0023] FIG. 3 is top view showing a chip in a nail coating at the end of a nail.
[0024] FIG. 4 is a cross section from lines B-B in FIG. 3 .
[0025] FIG. 5 is a top view of a nail showing the chip from FIG. 4 repaired according to the present invention.
[0026] FIG. 6 is a top view of the nail showing a chip 31 in coating 26 .
[0027] FIG. 7 is a cross-section along lines C-C taken from FIG. 6 .
[0028] FIG. 8 is FIG. 7 but with carrier 22 in the chip area 31 with additional indicia show light transmission relative to the carrier medium 22 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] The composition of the present invention provides a functional nail filling composition that has incorporated therewith, one or more materials for reflecting color of or equal to an adjacent material. In one embodiment, the composition is effective for filling any anatomical part of the nail or its coating.
[0030] The reflective material of the composition is dispersed, dissolved or suspended in a liquid or semi solid carrier. The carrier includes aqueous, organic, or cosolvent mixture of aqueous and organic solvents.
[0031] Finger 10 has a fingernail 12 at a distal end. Cuticle 14 is the interface between finger 10 and fingernail 12 . Fingernail 12 , as shown in FIG. 1 , has an upper surface 16 in which a crack 18 has been formed. Crack 18 has cavity 20 defining the boundary of crack 18 . Carrier 22 is placed into cavity 20 in one example by using a small brush that transfers the carrier from a container to the cavity. In one embodiment, carrier 22 includes a reflective material 24 incorporated within the carrier such that color from coating layer 26 is reflected outward from the carrier toward the observer. If coating 26 is not present on nail 12 , the natural color of upper surface 16 of the nail is reflected by reflective material 24 .
[0032] Carrier 22 is a composition preferably that evaporates in a approximately 10-120 seconds after application into cavity 20 . Carrier 22 also contains an appropriate carrier agent including any of fillers, dispersants, suspending agents, and combinations thereof as desired. In one embodiment, carrier 22 contains a cellulosic compound as a filler. Cellulosic compounds include, but are not limited to, methylcellulose, microcrystalline cellulose, propylcellulose, hydroxymethyl cellulose and hydroxypropyl methylcellulose. In one embodiment, carrier 22 includes keratin compositions similar to naturally occurring fingernail or toenail keratin.
[0033] Reflective material 24 is any material, element, compound, or molecule known to reflect color when positioned near a colored surface 16 or 26 . Reflective material 24 may include micronized crystalline solids of inorganic salts, known optical coating materials reflecting at least some portion of visible light (i.e. light in the visible spectrum), or materials in which selective reflectivity and transmitivity can be controlled and applied. Reflective material 24 in the present invention is preferably micronized and evenly distributed throughout carrier 22 . In one embodiment, reflective material 24 is micronized to 0.1-500 microns. Reflective material 24 need not have a regular or consistent shape, structure, or crystalline form. Any suitable material that reflects surrounding light is usable as reflective material 24 .
[0034] In another embodiment, carrier 22 , comprising a pigment and resin, has a refractive index, n, lower than the refractive index of polish 16 . At the carrier polish interface there exists an index where the difference refractive index of the carrier material is lower than the refractive index of the adjoining polish.
[0035] In use, the method of the present invention involves identifying at least one nail having an anomaly, such as, but not limited to, a crack;
[0036] providing a composition having at least one reflective material and a carrier;
[0037] applying said composition to said anomaly;
[0038] waiting a set period of time for said composition to cure.
[0039] In a preferred embodiment, the composition cures in 10-120 seconds.
[0040] As seen in FIG. 3 the anomaly is a chip 31 at the distal edge 32 of nail 12 . As seen in FIGS. 2 and 4 , chip 31 is either adjacent coating 26 , but generally on top of upper surface 16 of nail 12 or the upper surface of the nail 12 is more exposed. Carrier 22 is applied and placed within chip 31 and the adjoining areas of coating 26 so that the chip 31 is filled. Additionally a polishing cloth which may have a polishing compound can be used to smooth the new surface of the carrier 22 and adjoining polish 26 so the two surfaces are smooth at the point where they meet on the top surface. The new top surface 33 of coating 26 is substantially the same color as the original top surface before the chip as shown on FIG. 5 .
[0041] Referring to FIGS. 6 , 7 and 8 , which shows a cross section of the nail 12 , polish or coating 26 , and carrier 22 , with reflective material 24 . Ambient light 40 is shown in a direction-entering carrier 22 . At the surface of entry 41 , the top of carrier 22 , the light bends 42 as is known in the art. Within the carrier, the light reflects from at least 3 surfaces, the internal surfaces 43 between the coating 26 and carrier 22 . At this internal surface 43 , reflected light 44 reflects off surface 43 back into carrier 22 because of the lower refractive index of the carrier 22 compared to the higher refractive index of polish 26 . This reflected light 44 will disperse within carrier 22 and may further reflect from reflective material 24 and from nail surface 12 . Eventually reflected light 44 will transmit out of the carrier 22 at surface 41 and become visible red light that an observer will see as identical to or substantially the same color as the red surface 26 .
[0042] In another alternate embodiment, the carrier 22 will contain certain chemicals that will react upon contact with the previously applied nail polish 16 at initially wall 43 . This reaction will cause a color change throughout the carrier 22 . Carrier 22 will pick up the color properties and formula from polish 16 and morph into the same color. Therefore, the chip will have the same color as the adjoining polish 12 . This reaction will happen whether the chip is located in the center of the nail or other location. The color change of the carrier 22 will occur throughout carrier 22 prior to the carrier 22 setting or drying.
[0043] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention. | A composition and method is provided to repair fingernail and toenail anomalies. The composition is a carrier and reflective material that, when applied to a fingernail or toenail anomaly, fills said anomaly and reflects the nearby color, thereby reducing or eliminating the visual presence of the anomaly. | 0 |
This application is a continuation of application Ser. No. 150,833, filed Feb. 1, 1988, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a radial shaft sealing ring which comprises a stiffening ring having an angular profile with a first limb pointing radially inwardly and a second limb extending axially. A sealing lip disposed on the radially inwardly pointing end of the first limb extends substantially parallel to the second limb. An annular seal of rubber elastic material is disposed in recesses on the second limb in the area enveloping the first limb.
Such a radial shaft sealing ring is disclosed in West German Pat. No. 3,405,513. The stiffening ring that is used therein consists of deep-drawn sheet steel, which makes manufacturing expensive and makes it difficult to use automatic tools to install the radial shaft sealing ring when ready for use.
It is an objective of the present invention to devise a radial shaft sealing ring which overcomes these disadvantages of the design described above.
SUMMARY OF THE INVENTION
This objective, as well as other objectives which will become apparent in the discussion that follows, are achieved in the radial shaft sealing ring according to the invention, by providing tee stiffening ring, on its side facing away from the second limb of its L-shaped profile, with notches uniformly distributed around the circumference and open in the axial direction, so that the sealing lip and the annular seal may be joined integrally by connecting portions extending through the notches or recesses. The annular seal and the sealing lip are thus joined substantially more strongly to the stiffening ring. Consequently, under extremely severe assembly conditions, such as those involved for example in automatic assembly tools, separation is no longer a concern.
Also, within the forming die in which the sealing lip and the annular seal are formed and solidified on the stiffening ring, there is achieved a substantially more precise association between the stiffening ring and the die and, thus, the desired position within the completed and ready-to-use radial shaft sealing ring. On the one hand, this achievement simplifies manufacture and, on the other, it improves the properties the sealing ring will have when in use.
The stiffening ring of the radial shaft sealing ring according to the invention consists preferably of a very hard plastic whose elasticity modulus is considerably greater than that of the material forming the sealing lip. Both the sealing lip material and the material of the stiffening ring can be fabricated alternatively by the pressing method and/or by the injection molding method or injection embossing method, the two materials being able also to be fiber-reinforced, which especially in the case of the stiffening ring leads to an improvement of its mechanical strength. The shaping tools or dies used in the forming process permit an accurate, dimensionally precise transition between the too material components in the axial direction on the outside diameter.
The second limb can be provided on the end facing away from the first limb with an axially projecting and substantially annular thrust surface which is shifted radially inwardly with respect to its outer circumferential surface. The thrust surface runs substantially radially, its radial width in the same direction being able to be reduced to a minimum and, in the extreme case, to a surface appearing to be knife-edge-like.
Even in this case the result is a great bearing capacity with regard to the rotationally symmetrical shape of the stiffening ring. Even heavy axial loading which may result, for example, if the seal is forced excessively deep into the bore in the housing, will therefore, as a rule, result in no damage to the stiffening ring. At the same time the area of transition between the circumferential surfaces extending radially and those extending axially in the bore can be more generously proportioned. Thus it is not necessary to turn a sharp edge in this area or to provide at that point a very narrow transitional radius between the two surfaces. Both could be produced only with relatively great difficulty and would be accordingly complicated and expensive.
The thrust surface can be radially interrupted at least at one point on its circumference in order to enable the liquid medium, which in most cases is oil, to penetrate into the area between the outer circumferential surface of the stiffening ring and the circumferential surface of the receiving housing bore confronting it and to achieve the annular seal that produces the static sealing action. This annular seal consists of an elastomeric material and, therefore, if it has the customary qualities, it has a certain ability to swell. This property is utilized to achieve good sealing results and a tight seat in the housing bore, and is desirable when vibrations occur.
The stiffening ring can be provided at the end axially opposite the thrust surface with a substantially annular driving surface which is interrupted by the above-described notches in the stiffening ring regularly distributed around the circumference.
The installation forces needed for pressing the radial shaft sealing ring into its bore in the housing are applied to the driving surface. This driving surface for this reason forms a boundary surface of tee stiffening ring consisting of substantially unyielding material, so that this ring and the entire radial shaft sealing ring with it is associated with the installation tool in an especially precise manner. In the case of automatic assembly, therefore, there is no possibility that some individual radial shaft sealing rings will be driven to different depths than others.
The thrust surface and the driving surface can have approximately the same mean diameter, and it has been found desirable if the interior and exterior circumferential surfaces of the stiffening ring are all at a positive distance from an imaginary cylindrical surface whose diameter is the same as the average diameter of the thrust surface and driving surface. The resistance of the stiffening ring to buckling in the axial direction is thus decidedly improved, especially in cases in which the second limb of its L-shaped profile, extending in the axial direction, has, with the exception of the area of transition to the first limb, a thickness in the radial direction which increases steadily toward the middle of its axial length.
The recesses containing the statically sealing annular seal are filled completely by the annular seal and it is desirable that it have a depth in the radial direction that increases toward the driving surface.
The conical surface thus resulting, which is inclined with respect to the axis of the seal, forms with the seal axis a very low angle of 3° to 15° which, on the one hand, facilitates the axial driving of the radial shaft sealing ring according to the invention into the bore in a housing and, on the other hand, provides the installed radial shaft sealing ring with an especially tight seat in the bore. If an outwardly directed force is exercised in the axial direction on the installed radial shaft sealing ring, this causes a radial squeezing of the annular seal between the above-described conical surface and the housing wall confronting it. Both are completely unyielding, and this fact, combined with the resiliency of the rubber-elastic material forming the annular seal, results in a virtually inseparable bond between the installed radial shaft sealing ring and the bore in the housing.
The recesses can be defined radially inwardly by surface areas uniformly distributed around the circumference at different distances from the seal axis. In addition to an improved ability of the annular seal to yield, which is desirable for the installation procedures, the result of these recesses is an increase in the bonding area between the stiffening ring and the annular seal, which increases the strength of adhesion of the annular seal to the stiffening ring. These areas can be made to merge uniformly with one another and, in this case, form a uniformly wavy surface surrounding the seal axis. Sharp transition zones between the stiffening ring and the annular seal are absent in this case. The danger of the occurrence of separation of the material bodies forming the annular seal and the stiffening ring in the area of projecting or receding corners or edges is thereby definitely reduced.
The recesses can be defined at the end remote from the driving surface by a ramp. This ramp can best form with the seal axis on the side facing the recess an angle (B) of about 90° to 150°, thereby securely avoiding any parting of the annular seal from the carrier ring within the area in question, for example when the seal is pressed into its bore.
The ramp can be uniformly curved into the surface defining the recesses in the radial direction. The strength of adhesion between the areas of the annular seal and stiffening ring which confront one another in this area is thereby increased.
Furthermore, it has been found to be advantageous if the ramp is sharply defined against the external circumferential surface of the stiffening ring. The annular seal subsequently formed on the stiffening ring is thereby precisely defined with respect to the stiffening ring which consists of a different polymeric material, which improves the external appearance and gives the annular seal a high quality appearance.
If a material capable of swelling is used for the production of the annular seal and of the lip seal, it has generally proven sufficient if the outside diameter of the annular seal is substantially the same as the diameter of the outer circumferential surface of the stiffening ring and bore. The necessary contact pressure between the annular seal and the wall of the bore is based in this case on the swelling of the annular seal which results from wetting by the medium that is being sealed. If, however, complete security is not achieved in this regard, due for example to the use of certain high-quality rubber-elastic materials, then it has been found desirable to give the annular seal an outside diameter that is slightly greater than the diameter of the outer circumferential surface of the stiffening ring.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject of the present invention will be further explained below with the aid of the appended drawings.
FIG. 1 is a cross-sectional view through half of an exemplary embodiment of the radial shaft sealing ring according to the invention.
FIG. 2 is an elevational view of the radial shaft sealing ring shown in FIG. 1, as seen from the left.
FIG. 3 is a cross-sectional view of the radial shaft sealing ring shown in FIG. 1, taken along the line A--A therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The radial shaft sealing ring shown in FIG. 1 consists of a stiffening ring 1 of a hard and tough plastic having an L shaped cross-sectional profile of which a firs limb 2 projects radially inwardly and a second limb 3 projects axially. These two limbs are integral with one another.
The first limb 2 is provided on the side facing away from the second limb with notches uniformly distributed around the circumference and open in the axial direction, through which the connecting sections 6 of the annular seal and the sealing lip pass resulting in a configuration of the two bodies of material in which one merges with the other. The annular seal 5, the connecting sections 6 and the sealing lip 4 consist therefore of a single body of rubber-elastic sealing material.
This body is relatively soft and elastic and is joined to the body forming the stiffening ring 1 by being formed and vulcanized directly on the latter.
The sealing lip 4 has the dust lip 18 integrally formed on it, as well as a sealing edge 19 on the outer side of which an annular coil spring 20 of metal material is provided.
Thus, a uniform urging of the sealing edge 19 against the shaft to be sealed, which is not shown, is assured over long periods of time, and this assures the achievement of a seal which can withstand the severest stresses.
The stiffening ring 1 has at its opposite ends a driving surface 9 and a thrust surface 7. The two have identical mean diameters which are joined together in FIG. 1 by an imaginary cylindrical surface 10. The outer circumferential surface 8 and the inner circumferential surface 11 of the second limb of the L-shaped profile of the stiffening ring are each at a positive distance from the cylindrical surface 10, which provides the axially projecting, second limb 3 of the stiffening ring with an excellent resistance to buckling. The radial shaft sealing ring according to the invention can therefore be installed easily, allowing even a hard abutment against the bottom of the housing bore thatreceives it. The result is a considerable simplification with regard to the use of automatic installation tools.
The thrust surface 7 is radially offset from the outer circumferential surface 8 of the stiffening ring 1. The transition between the bottom of the housing bore and its circumferential surface can thus be relatively loosely configured.
Thus it is no longer necessary to provide sharp-cornered bores in this area, which are expensive to produce.
The driving surface 9 axially opposite the thrust surface 7 is part of the hard, tough and substantially unyielding stiffening ring 1. In automatically operating installation tools, this assures a precise relationship between the radial shaft sealing ring and the installation tool even while the ring is being pressed in place, and this makes it easier to achieve a precise seat in the bore in the housing.
The second limb 3 of the L-shaped profile has recesses 12 in which the annular seal 5 is disposed. Such recesses are defined inwardly substantially by the surfaces 13 and 14 which are at a varying distance from the seal axis 16 and which merge with one another circumferentially to form waves. Furthermore, the surfaces 13 and 14 as well as the transitions between the latter are inclined at a low angle toward the seal axis 16, so that, when the sealing ring shown in FIG. 1 is pressed axially to the ring into the housing bore, the annular seal 5 of matching profile is able easily to yield in the leftward direction. This simplifies the process of pressing the seal in place. Nevertheless, due to the slightly larger outside diameter of the annular seal 5 with respect to the diameter of the outer circumferential surface 8 of the stiffening ring, the result is a good radial compression of the annular seal 5 between the surfaces enveloping it radially on both sides.
At the end remote from the driving surface, the recesses 12 are terminated by a ramp 15. This ramp forms an angle B of about 90° to 150° with the seal axis on the side facing the recess, thereby securely avoiding any parting of the annular seal from the carrier ring within the area in question when the seal is pressed into its bore.
In addition to a good sealing of the radial shaft sealing ring against the housing bore, this arrangement also achieves a tight seating. Such tight seating is further promoted by the fact that a leftward relative movement of the installed radial shaft sealing ring with respect to the housing bore (FIG. 1) would lead to a extremely high radial compression of the annular seal 5 with respect to the annular surfaces enveloping it internally and externally. The annular seal 5, however, consists of an incompressible material. The nondestructive removal of the installed radial shaft sealing ring is therefor not easily possible, nor is any loosening of the installed radial shaft sealing ring possible as a result of the introduction of vibrations.
There has thus been shown and described a novel radial shaft sealing ring which fulfills all the objects and advantages sought thereafter. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiment thereof.
All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. | A radial shaft sealing ring comprises a stiffening ring as well as a sealing lip and an annular seal which are integrally combined by radial connecting sections running through notches in the stiffening ring. The annular seal is mounted in recesses in the stiffening ring, which have an increasing depth radially toward the driving surface. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application is a divisional of U.S. patent application Ser. No. 12/682,457, filed Jul. 15, 2010, which is a national stage filing under 35 U.S.C. 371 of International Application No. PCT/EP2008/063626, filed Oct. 10, 2008, which claims priority to European Patent Application No. 07291232.2, filed Oct. 10, 2007, the disclosures of each of which are incorporated by reference herein in their entirety for any purpose. Priority to each application is hereby claimed.
FIELD OF THE INVENTION
The present invention relates to methods and medicaments intended to cure cancers, such as malignant mesothelioma.
BACKGROUND OF THE INVENTION
Malignant mesothelioma (MM) are relatively rare and highly aggressive neoplasms, arising from the uncontrolled proliferation of mesothelial cells lining serosal cavities, most commonly the pleura (Malignant Pleural Mesothelioma or MPM) (Robinson et al. (2005) Lancet 366:397-408). Epidemiologic studies have established that exposure to asbestos is one of the most important MPM etiologic factor in industrialized countries (Gruber (2005) Lung Cancer 49S1:S21-S23; Bartrip (2004) Postgrad Med. J. 80:72-76). Although worldwide usage of asbestos has been considerably reduced, the incidence of mesothelioma is expected to rise in the next two decades, because of a long latency period (20 to 40 years) between asbestos exposure time and clinical symptoms apparition.
Today, cancer diagnosis is usually established at an advanced stage because of the absence of overt symptoms in the early period of the disease, thus making poor the prognosis for mesothelioma patients. Consequently, MPM is actually considered as a cancer relatively refractory to all conventional treatment modalities. Accordingly, there is a pressing need for the development of new therapeutic approach.
During the past decade, there has been an increasing interest in virotherapy, partly related to the growing knowledge in the production of recombinant viral vectors for human gene therapy. Numerous RNA replicating viruses are now considered as potential cancer therapeutics. As such, therapy of MPM using engineered replication-competent Herpex Simplex Viruses (HSV) has been proposed, based on in vitro studies and results obtained on a murine model of MPM (Adusumilli et al. (2006) J. Gene Med. 8:603-615). However, the long term safety of these engineered viral vectors in humans is not known and extensive clinical trials will be necessary to document this aspect of HSV usage.
Accordingly, there is a need for viral vectors with recognized safety liable to be used in the frame of mesothelioma treatment.
MV (Measles Virus) is an enveloped, negative single strand RNA virus belonging to the Paramyxoviridae family, genus Morbilli virus. Various replication-competent live attenuated strains of MV have been developed for producing vaccines against measles. By way of example, Schwartz, Moraten, or Zagreb (which are derived from MV samples isolated from an Edmonston patient) are safe and well-documented MV vaccine strains.
It has been shown recently that in vivo administration of a replication-competent Edmonston MV strain resulted in growth slowing or sometimes regression of tumors established animal models of lymphoma and myeloma cancer (Grote et al. (2001) Blood 97:3746-3754; Peng et al. (2001) Blood 98:2002-2007). Besides, Anderson et al. (2004) Cancer Res. 64:4919-4926, have shown in in vitro experiments that high CD46 expression by tumor cells was necessary for the infection and the killing of these cells by a live attenuated Edmonston MV strain. However, it is known that CD46 is variably expressed by human carcinomas (Niehans et al. (1996) American J. Pathol. 149:129-142), thereby casting doubts on the general applicability of live attenuated MV strains for treating cancers.
SUMMARY OF THE INVENTION
The present invention arises from the unexpected finding, by the present inventors, that attenuated measles virus could efficiently infect and kill mesothelioma cells. Furthermore, the present inventors have shown that dendritic cells contacted with lysate from attenuated measles virus-infected mesothelioma cells could activate anti-mesothelioma CD8 T cells.
Thus, the present invention relates to an attenuated measles virus for use in the treatment of malignant mesothelioma in an individual.
The present invention also relates to the use of at least one attenuated measles virus for the manufacture of a medicament intended for treating malignant mesothelioma in an individual.
The present invention also relates to a method for treating malignant mesothelioma in an individual, wherein a therapeutically effective quantity of at least one attenuated measles virus is administered to said individual.
The present invention further relates to a method for preparing vaccinal dendritic cells intended for treating cancer in an individual, comprising the following steps:
in vitro infection of cancer cells, preferably taken from the individual, by an attenuated measles strain to yield a cell lysate;
contacting dendritic cells with the cell lysate to yield vaccinal dendritic cells.
The present invention also relates to vaccinal dendritic cells liable to be obtained by the above-defined method of preparation, to a pharmaceutical composition comprising said vaccinal dendritic cells as active ingredient, in association with a pharmaceutically acceptable carrier, to said vaccinal dendritic cells for use in the treatment of cancer in an individual, and to the use of said vaccinal dendritic cells, for the manufacture of a medicament intended for treating cancer in an individual.
The present invention further relates to a method for treating cancer in an individual, wherein a therapeutically effective quantity of vaccinal dendritic cells liable to be obtained by the above-defined method of preparation are administered to said individual.
DETAILED DESCRIPTION OF THE INVENTION
As intended herein, the individual is preferably a mammal, more preferably a human. Preferably also, the individual has been exposed to asbestos.
As intended herein, the expression “attenuated measles virus” designates any virus derived from a measles-causative virus and presenting a decreased virulence with respect to said measles-causative virus. As intended herein the attenuated measles virus can be derived from measles-causative virus by any technique known to the man skilled in the art, such as serial passages on cultured cells and/or genetic engineering. In particular, the attenuated measles virus may be a recombinant virus, optionally expressing additional genes. More particularly, the attenuated measles virus may be a measles virus wherein the expression of one or more proteins, preferably the accessory C protein, is abolished. It is preferred that the attenuated measles virus causes essentially no measles symptoms when administered to a human. Besides, the attenuated measles virus is preferably alive and replication-competent.
Preferably, the attenuated measles virus is an Edmonston strain. Edmonston strains of attenuated measles virus are well-known to one of skill in the art and are notably described in Griffin (2001) Field's Virology 4 th Edition vol . 2 Knipe and Howley (ed.) Lippincott-Raven Publishers, Philadelphia, 1401-1441; Hilleman (2002) Vaccine 20:651-665). More preferably, the attenuated measles virus is selected from the group constituted of a Schwartz strain and a Moraten strain. These strains, which genomes have been shown to be identical, are well-known to the man skilled in the art and are widely used for the production of vaccines against measles. They are notably described in Schwarz (1962) Am. J. Dis. Child 103:216-219; Parks et al. (2001) J. Virol. 75:921-933 and Parks et al. (2001) J. Virol. 75:910-920. Most preferably, the attenuated measles virus is produced from the pTM-MVSchw plasmid (SEQ ID NO: 1) described by Combredet et al. (2003) J. Virol. 77:11546-11554.
Cancers to be treated within the frame of the present invention are preferably malignant mesotheliomas, more preferably malignant pleural mesotheliomas or peritoneal mesotheliomas, most preferably malignant pleural mesotheliomas. Such cancers are notably described in Kazan-Allen (2005) Lung cancer 49S1:S3-S8 and Robinson et al. (2005) Lancet 366:397-408.
Where the attenuated measles virus is administered to an individual, it can be administered through the intrapleural cavity or by the intranasal, intramuscular, intravenous or subcutaneous routes. Where the attenuated measles virus is administered through the intrapleural cavity, it is preferably administered in close proximity or directly into the tumors to be treated. If necessary, the attenuated measles virus can be associated to any suitable pharmaceutically acceptable carriers. The therapeutically effective quantity of attenuated measles virus to be administered is preferably in the range of from 10 3 to 10 6 50% tissue culture infective doses (TCID50). TCID50 determination is well known to one of skill in the art and is notably described by Karber (1931) Arch. Exp. Path. Pharmak. 162:840-483.
The step of taking the cancer cells from the individual to be treated by the vaccinal dendritic cells is preferably not included in the above-defined method of preparation of vaccinal dendritic cells. This step can proceed according to any technique known to one of skill in the art for taking cells, such as biopsies and effusions (e.g. pleural effusions). After being taken, the cancer cells can be maintained in culture according to classical techniques, or frozen (e.g. at −80° C.) for conservation, for instance. Where the cancer cells do not originate from the individual to be treated by the vaccinal dendritic cells, they can notably derive from allogenic human mesothelioma cell lines.
In the above-defined method of preparation, infection of the cancer cells by the attenuated measles virus can proceed by directly contacting cells and virus, for instance at a Mutliplicity Of Infection (MOI) of 1, with an incubation of 2 hours at 37° C. After infection, death of the infected cells proceeds spontaneously due to virus action. A syncitia is usually first formed followed by lysis of the cells. This phenomenon can be evidenced by direct microscopic observation of infected cells. As intended herein “cell lysate” encompasses both whole (or total) cell lysate, or fractions of the cell lysate, such as membrane fractions (e.g. cytoplasmic inclusion bodies or apobodies). As will be well-understood by those skilled in the art, the cell lysate obtained in the first step of the above-defined method of preparation corresponds to a virus infected cancer cell lysate.
Dendritic cells can be obtained by numerous ways well known to the man skilled in the art. The dendritic cells preferably originate from the individual to be treated. It is presently preferred that the dendritic cells are monocyte-derived dendritic cells. The obtention of monocyte-derived cells is particularly well known to one of skill in the art. Preferably, monocyte-derived cells can be obtained following the general methodology described in Example 4 or by Spisek et al. (2001) Cancer Immunology Immunotherapy 50:417-427, or by Royer et al. (2006) Scand. J. Immunol. 63:401-409. Where the monocyte-derived dendritic cells originate from the individual to be treated, monocytes can be obtained from leukapheresis of said individual.
As will be apparent to one skilled in the art, contacting of the dendritic cells and of the cell lysate should be maintained for a time sufficient to enable an effective loading of the dendritic cells by antigens present in the cell lysate. Once loaded (or pulsed), vaccinal dendritic cells according to the invention are obtained. Loading can proceed by following the general methodology described in Example 4. An exemplary contact period between dendritic cells and the cell lysate sufficient to enable efficient loading of the dendritic cells is of about 24 hours. In particular, the contact period can be maintained until the dendritic cells are in an activated state. The activated state is usually reached after the dendritic cells have been loaded. The activated state (or mature state) of dendritic cells can be evidenced by numerous markers well known to one of skill in the art, such as membrane or cytokine markers. Such markers of activated dendritic cells are notably listed in Example 5.
Thus, vaccinal dendritic cells obtainable according to the method of preparation of the invention are particularly advantageous since they are potent stimulators of anti-cancer CD8 T cells. Equally advantageous, the method of preparation according to the invention allows the preparation of vaccinal dendritic cells in an activated state.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1, 2, 3, 4 and 5 : Mesothelioma susceptibility to attenuated Measles Virus (MV).
FIG. 1 —Selective Oncolytic activity of Schwarz MV vaccine strain. A panel of human epithelioid mesothelioma cell lines (M11, M13, M47, M56 & M61) and an immortalized normal mesothelial cell line (Met5A) were infected with non-recombinant MV (MOI 1.0) and microscope observations of infected cultures morphology were performed 72 hours later.
FIGS. 2-3 —Higher surface expression level of CD46 receptors for tumoral cells in comparaison with their normal counterparts. Cells were stained with FITC-conjugated CD46-specific antibodies (grey histogram) or related isotype Ig control (white histogram) ( FIG. 2 ). Numbers indicate the mean fluorescence index and histogram shows mean values of CD46 expression obtained for mesothelial (white bar) and mesothelioma (hatched bar) cell lines ( FIG. 3 ).
FIGS. 4-5 —Schwarz MV vaccine strain preferentially infects transformed tumoral cells. Equal numbers of M13 and Met5A cells were cultured separately ( FIG. 4 ) or co-cultured ( FIG. 5 ) overnight, allowing cellular adherence, and infection was done at MOI of 1.0 with eGFP-recombinant MV. In separate cultures, analysis of eGFP expression was performed at different times post-infection (24, 48, & 72 hours) by flow cytometry ( FIG. 4 ). In co-culture model, the same experiment was conducted along with HLA-A2 staining, as HLA alleles differential expression allowed distinction between two cell lines. Histogram shows % eGFP-positive cells for Met5A (white bar) and M13 (black bar) cells from co-culture ( FIG. 5 ).
FIG. 6 : Immunogenicity of MV-infected mesothelioma cell line.
FIG. 6 —Cellular death induced by MV- and UV-treatments. Flow cytometry analysis of M13 tumoral cells apoptosis triggered by UV exposure (5 kJ/cm 2 ) or MV infection (MOI=1.0) at the indicated time points (D1=24 h, D2=48 h, D3=72 h, and D4=96 h) (hatched bars) vs. untreated control cells (white bars).
FIGS. 7 and 8 : Phagocytosis of apobodies by monocyte-derived DCs.
FIG. 7 —UV- or MV-treated M13 tumor cells were labelled with PKH-26 and co-cultured with immature DCs for 24 hours. Harvested DCs were subsequently stained with FITC-conjugated anti HLA-DR antibodies and analysed by flow cytometry. One representative experiment of three with similar results is shown. The number of double-positive DCs, that is the percentage of PKH-26 positive DCs gated on basis of HLA-DR expression (FITC-conjugated antibodies, clone B8.12.2, Immunotech), indicates the phagocytosis efficiency of apoptotic cells.
FIG. 8 —The histogram represents mean values of phagocytosis yield obtained for each loading condition tested.
FIGS. 9, 10 and 11 : DC maturation induced by co-culture with MV-infected mesothelioma cells.
FIGS. 9 and 10 —Immature DCs and M13 tumoral cells were cultured in the indicated combinations (ratio 1/1) for 24 hours. As controls, DCs were incubated with TLR3 ligand, polyinosinic:polycytidylic acid (50 μg/ml; Sigma), or directly infected with MV (MOI=1.0). Subsequently DCs were harvested and stained with a PE-conjugated antibody panel specific for the indicated cell surface molecules ( FIG. 9 —HLA molecules; FIG. 10 —Maturation Markers). DCs were gated according to their morphology characteristic, and dead cells were excluded on basis of TOPRO-3 staining (Molecular Probes). DCs surface phenotype was analysed by three-colors flow cytometry. Histogram shows means values obtained from four independent donors.
FIG. 11 —DC cytokine secretion pattern was investigated on 24 hours supernatant co-culture by CBA (for IL-6, IL-1β, TNFα, IL-12 & IL-10) and ELISA (for IFNα) assays.
FIG. 12 : DCs loaded with MV-infected mesothelioma cells induce MSLN-specific CD8 T cell priming.
FIG. 12 —Number of MSLN-specific CD8 T cells, derived from one week sensitization co-culture with unpulsed or UV-M13 or MV-M13 pulsed DCs, was analysed by flow cytometry. Histogram indicates the percentage of PE-tetramer positive cells among T cells gated on basis of human CD8 expression (PE-Cy5-conjugated antibodies, clone RPA-T8, BD Biosciences). One representative experiment is shown.
EXAMPLES
Example 1
Mesothelioma Susceptibility to MV Infection and Oncolytic Activity
To compare MV-related cytopathic effect on tumoral and non-tumoral cells, a panel of five epithelioid mesothelioma cell lines (M11, M13, M47, M56, and M61) and mesothelial cells (Met5A) were infected with a Schwarz vaccine strain at a Multiplicity Of Infection (MOI) of 1.0.
The mesothelioma cell lines (M11, M13, M47, M56, and M61) were established from pleural effusion collected by thoracocentesis of cancer patients. Diagnosis of epithelioid mesothelioma was established by biopsies immunohistochemical staining. The control mesothelial cell line (Met5A) was isolated from pleural fluids of cancer-free patients and immortalized by transfection with the pRSV plasmid encoding SV40 T-antigen (ATCC-LGC Promochem, Molsheim, France). Cell lines were maintained in RPMI-1640 medium supplemented with 10% heat-inactivated Foetal Calf Serum (FCS from Biowest, Nuaille, France), 1% L-glutamine and 1% penicillin/streptomycin antibiotics (all purchased from Sigma, St Quentin Fallavier, France). Cellular cultures were routinely checked for Mycoplasma contaminations using Hoechst 33258 staining (Sigma).
Attenuated MV Schwarz vaccine strains were obtained from F. Tangy (Pasteur Institut, France). Schwarz MV was rescued from the pTM-MVSchw (SEQ ID NO: 1) cDNA by use of the helper-cell-based rescue system described by Radecke et al. (1995) EMBO J. 14:5773-5784 and modified by Parks et al. (1999) J. Virol. 73:3560-3566. Briefly, 293-3-46 helper cells were transfected with 5 μg of pTM-MVSchw and 0.02 μg of pEMC-Lschw expressing the Schwarz MV-L gene (Combredet et al. (2003) J. Virol. 77:11546-11554) (SEQ ID NO: 2). After overnight incubation at 37° C., a heat shock was applied for 2 h at 43° C., and transfected cells were transferred onto a Vero cell monolayer. Syncytia that appeared in 15 days coculture were transferred to 35-mm wells and then expanded in 75-cm 2 and 150-cm 2 flasks of Vero cells culture in 5% FCS DMEM. When syncytia reached 80-90% confluence, the cells were scraped into a small volume of OptiMEM and frozen-thawed once. After low-speed centrifugation to pellet cellular debris, virus-containing supernatant was stored at −80° C. The titer of recom binant MV stock was determined by an endpoint limit-dilution assay on Vero cells. The TCID50 was calculated by use of Kärber method (Karber (1931) Arch. Exp. Path. Pharmak. 162:480-483).
Viral infections of the mesothelioma cell lines were performed at a MOI=1.0 for 2 hours incubation at 37° C. Three days following MV infection, typical morphological modifications of MV-infected cells were observed, that is development of an important cytopathic effect (CPE) on most tumoral MPM lines (4/5), by contrast with non cancerous Met5A cells ( FIG. 1 ). CPE was evidenced through development of more or less important syncitia, which finally led to shedding in culture supernatant of cytoplasmic inclusion bodies of dead tumoral cells ( FIG. 1 ). The development of these multinucleated giant syncitia is characteristic of measles infection and is produced by fusion of HA + infected cells with neighbour CD46 + culture cells.
A significant upregulated expression of live-attenuated MV strains receptor CD46 by mesothelioma cells could be evidenced ( FIGS. 2-3 ).
In order to quantify susceptibility to MV infection, Met5A and M13 cell lines were infected with eGFP-recombinant MV stock (Combredet et al. (2003) J. Virol. 77:11546-11554). The GFP-transgene expression was used as a marker of viral infection, thus allowing determination of infected cells percentage by flow cytometry. MV infection yield of both culture cells was dose-dependent (MOI ranging from 0.01 to 5.0), indicating the specificity of eGFP signal. Whereas Met5A was infected by the MV strain (for MOI ranging from 0.5), M13 was also significantly infected by MV, but always at lowest MOI (for MOI ranging from 0.1). A significant increased infection yield of tumour cells in comparison to normal cells (for MOI 1.0), was also observed both in cellular separate culture ( FIG. 4 ) and co-culture ( FIG. 5 ) systems (ratio 1:3) at 48 hours post-infection. Moreover, virus infection could also be evidenced by down-regulation of CD46 surface expression observed in infected cellular cultures.
Thus, according to these in vitro results, mesothelioma tumors present a more important susceptibility both to MV-mediated infection and MV-related cytolytic activity than mesothelial tissue. Consequently, MPM appears as a relevant candidate for virotherapy approach based on measles virus administration.
Example 2
Tumoral Cell-Death Induced by MV and UV Treatments
After demonstrating that MV is able to infect mesothelioma cells, the inventors verified if virus infection could also lead to apoptosis-mediated cell death.
Sub-confluent monolayer M13 cells culture were either MV-infected (MOI 1.0), or UV-B-irradiated (312 nm-5 kJ/m 2 ) using an UV Stratalinker2400 (Stratagene Europe, Amsterdam, Netherlands), as positive control for apoptosis. Cells were collected at different times post-treatment, and cellular death was quantified as described by Ebstein et al. (2004) Am. J. Respir. Crit. Care Med. 169:1322-1330 by concomitant phosphatidylserine and Annexin-V stainings.
As shown in FIG. 6 , 24 hours exposition of M13 cells to UV-B irradiation and 72 hours infection of M13 cells with MV yielded an equivalent rate of tumoral cell death (comprised between 70% and 80% of Annexin-V positive cells), which indicates that MV induces apoptosis in infected tumor cells. The thus-defined M13 cell death-induced conditions were used in following experiments.
Moreover, virus-related cell killing was also confirmed by observation of an important cytopathic effect, leading to complete dislocation of M13 cellular layer 72-96 hours post-infection ( FIG. 1 ).
Example 3
Follow-Up of Viral Replication Cycle in MV-Infected Tumoral Cells
In order to follow viral growth kinetic in infected M13 cells culture (MOI=1.0), RT-PCR specific for viral dsRNA potential receptors (Mda-5, TLR-3, RIG-I and PKR) were performed. Specific primers for the β-actin gene were used as an internal experiment control.
Briefly, M13 cells were either incubated with polyinosinic:polycytidylic acid ligand (10 μg/ml) or MV (MOI=1.0) and cellular pellets were collected at different times. Whole cellular RNA was then extracted using RNeasy kits (Qiagen, Courtaboeuf, France) according to manufacturer's instructions, and reverse-transcribed using RTase (Invitrogen, Paisley, UK). Resulting cDNA was used as template for PCR amplification using primers specific for Mda-5, TLR-3, RIG-I, PKR, IFNβ, and β-actin. PCR primers sequences are listed in Table 1. PCR products were visualized by agarose gel electrophoresis.
TABLE 2
primer sequences
Fragment
SEQ
size
ID
Primer
Sequence
(bp)
NO:
β-actin
Forward ATCTGGCACCACACCTTCTACAATGAGCTGCG
837
3
Reverse CGTCATACTCCTGCTTGCTGATCCACATCTGC
4
TLR-3
Forward ATTGGGTCTGGGAACATTTCTCTTC
319
5
Reverse GTGAGATTTAAACATTCCTCTTCGG
6
Mda-5
Forward GAGCAACTTCTTTCAACCAC
633
7
Reverse GAACACCAGCATCTTCTCCA
8
RIG-I
Forward GAACGATTCCATCACTATCC
580
9
Reverse GGCATCATTATATTTCCGCA
10
PKR
Forward CTTCTCAGCAGATACATCAG
689
11
Reverse GTTACAAGTCCAAAGTCTCC
12
It could thus be shown that a viral replication peak occurred between 1 day to 4 days post-infection of mesothelioma M13 cells. Besides, PCR products corresponding to viral dsRNA potential receptors (Mda-5, TLR-3, RIG-I and PKR) could also be evidenced.
Example 4
Efficient Uptake of Apoptotic Mesothelioma Cells by Immature DCs
The uptake by dendritic cells (DCs) of apobodies from MV-infected (72-hours) was then studied and compared to that of UV-irradiated (24-hours) M13 tumoral cells.
Dendritic cells were derived from monocytes generated from leukapheresis harvests of HLA-A0201 healthy donors (EFS, Nantes, France), after obtaining informed consent. Monocytes-enriched fraction (>85% purity) was first separated by Ficoll density gradient centrifugation (PAA Laboratories, Les Mureaux, France). Monocytes were then enriched by elutriation (counterflow centrifugation) using a Beckman Avanti J20 centrifuge equipped with a JE5.0 rotor and a 40-ml elutriation chamber. Routinely, purity of elutriated monocytes was over 80%, as assessed by flow cytometry based on the detection of the CD14 marker. Monocytes were cultured at 2×10 8 cells/ml with 500 IU/ml GM-CSF and 200 IU/ml (Cell Genix Technology, Freiburg, Germany). Cells were then allowed to differentiate for 6 days.
On day 6, monocytes-derived DCs were collected from culture supernatant and seeded in culture for subsequent loading. Immature DCs were incubated with 2.10 8 cells/ml of apoptotic material, derived from UV-treated or MV-infected allogenic M13 tumoral cells, for additionally 24 hours co-culture (ratio 1:1). DC phagocytosis yield analysis was assessed both by flow cytometry and confocal laser microscopy, as previously described (Massé et al. (2002) Cancer Research 32:1050-1056). Briefly, UV- or MV-treated M13 cells were labelled with PKH-26 membrane dye colorant, according to the manufacturer's protocol (Sigma, St Quentin Fallavier, France). After 24 hours co-culture, DCs were stained with FITC-conjugated anti HLA-DR antibodies (Immunotech, Marseilles, France). After PBS washes, cells were harvested and analysed either on a FACSCalibur (BD Biosciences, Grenoble, France), or with a TCS NT microscope (Leica Instruments, Heidelberg, Germany). DCs that have ingested apoptotic cells were identified as HLA-DR/PKH-26 double positive cells ( FIG. 7 ).
As shown in FIG. 8 , it could be evidenced that DCs efficiently engulfed UV- and MV-treated mesothelioma cells at the same rate, as illustrated by a similar percentage of PKH26-positive DCs gated on basis of HLA-DR expression (65% and 74% for DCs loaded respectively with UV- or MV-treated M13 cells).
Confocal laser-scanning microcopy experiments further confirmed an efficient internalization of apoptotic M13 cells by immature DCs within 24 hours co-culture, irrespective of the death-induced strategy used (MV-infected or UV-irradiated).
Example 5
Tumor Cells Infected with MV Induce Spontaneous DC Maturation, by Contrast with UV Radiation-Induced Apoptotic M13 Cells
The inventors next examined whether cell material derived from MV-infected M13 tumoral cells could efficiently stimulate DC maturation.
DC maturation status was assessed within 24 hours following engulfment of tumoral cells killed either by radiation exposition or virus-mediated cytolytic activity.
Phenotype of viable DCs (gated on basis of TOPRO-3 positive staining exclusion) was investigated by surface expression of Class I and II MHC molecules ( FIG. 9 ) and of maturation markers CD80, CD86, CD83 and CD40 ( FIG. 10 ), completed by cytokines secretion pattern analysis performed on co-culture supernatant ( FIG. 11 ). As controls, DCs were left alone, or matured with a combination of TLR3 ligand and one pro-inflammatory cytokine (polyinosinic:polycytidylic acid/IFNα, as a mimick of viral infection), or directly primed by measles virus contact (MV).
Briefly, immunostaining was performed with a panel of monoclonal antibodies (all purchased from Immunotech, Marseilles, France) specific for HLA-ABC (clone B9.12.1), HLA-DR (clone B8.12.2), CD80 (clone MAB104), CD83 (clone HB15a), CD86 (clone HA5.2B7), and CD40 (clone MAB89). DCs were incubated with each of the above antibodies (1 μg/ml) at 4° C. for 30 min prior to flow cytometry. Cytokines pattern secretion was assayed in supernatants collected 24 hours after engulfment. IL-10, IL-12, IL-6, IL-1β and TNFα concentrations were measured using commercially available Cytometric Beads Array kits (BD Biosciences, Le Pont de Claix, France), according to the manufacturer's protocol. Quantification of IFNα was performed with an ELISA test (Biosource, Camarillo, USA).
A spontaneous maturation program could be observed only for DCs loaded with apobodies derived from mesothelioma cells infected with MV, at a level essentially equivalent to the positive control maturation cocktail used in the experiment (Polyl:C/IFNα). Spontaneous maturation was evidenced by significant up-regulation of co-stimulation molecules expression (for CD80, CD83, CD86, CD40 and HLA-ABC), and production of numerous pro-inflammatory cytokines (for IL-6, IL-1β, TNFα, and IFNα).
However, in line with previous reports, pulsing DCs with UV-irradiated apoptotic tumoral cells, as well as direct infection of DCs by measles virus (MV), did not lead to this effect.
Overall these data strongly support an increased immunogenicity of MV-infected tumoral cells with respect to UV-irradiated tumoral cells.
Example 6
Cross-Priming of MSLN-Specific CD8 T-Cell Response
Finally, the inventors tested whether DCs loaded with apobodies derived from mesothelioma cells infected with MV could stimulate an effector CD8 response specific for an MPM-associated tumor antigen, such as Mesothelin (MSLN).
In order to assess this question, tetramer immunostaining was performed on CD8 T-lymphocytes sensibilized for one-week with autologous DCs loaded with apoptotic material derived from UV- or MV-treated M13 cells. As controls, a similar experiment was conducted with the Jurkat lymphoma T-cell line, chosen on the basis of its susceptibility to MV and its MSLN-negative expression characteristics ( FIG. 12 ). As internal experiment controls, MelanA/Mart-1-specific tetramer staining (MelanA26-35L) was achieved in complement of those specific for the two selected MSLN-derived CTL epitopes. These peptides (MSLN 531-539 and MSLN 541-550) were identified by scanning MSLN amino-acid sequence (GenPept NP 005814) for matches to consensus motifs for HLA-A0201 binding, using two computer algorithms BIMAS and SYFPEITHI (Table 2):
TABLE 2
tetramer characteristics
HLA-A0201 binding
score
Tetramer name
Localisation
Sequence
SYFPEITHI
BIMAS
HLA-A2 VLP9
531-539
VLPLTVAEV
29/30
272/285
(SEQ ID NO: 13)
HLA-A2 KLL10
541-550
KLLGPHVEGL
30/31
312/312
(SEQ ID NO: 14)
Briefly, CD8 T lymphocytes were prepared from HLA-A0201 healthy donors PBMCs by positive selection with the MACS column systems using CD8 multisort kit (Miltenyi Biotec, Paris, France). Purified naïve CD8 T cells (>90% purity) were stimulated with autologous DCs loaded with each apoptotic preparation or unloaded DCs as a control. The co-culture was performed in round bottom 96-well plates (BD Falcon), by mixing 2.10 4 mature DCs with 2.10 5 responder T cells (ratio 1:10) in 200 μl of 8% human serum RPMI 1640 medium, supplemented with 10 ng/ml IL-12 for the first 3 days (AbCys SA, Paris, France) and with 10 U/ml IL-2 (Proleukin, Chiron Therapeutics, USA) for the next days. IL-2 was added every three days, allowing regular culture medium renewal. After 7-8 days culture, T cells were harvested and stained with MSLN-specific tetramers as follows.
The selected CD8 epitope peptides (synthesis performed by Eurogentec, Liege, Belgium) were used for monomers production (Recombinant Proteins Production Platform, U601-IFR26, Nantes, France) as previously described (Labarrière et al. (2002) Int. J. Cancer 101:280-286). HLA-A2 VLP9 and HLA-A2 KLL10 monomers were oligomerized with PE-labeled streptavidin (BD Biosciences). Staining and washing were performed in 0.1% BSA-PBS. T cells were stained successively with 10 μg/ml of PE-labeled pMHC multimers at 4° C. for 30 min, and with 1 μg/ml diluted PE-Cy5-conjugated anti-CD8 antibodies (clone RPA-T8, BD Biosciences) for additionally 30 min at 4° C. Cells were washed and immediately analysed on a FACSCalibur.
Interestingly, a significant increase of MSLN-specific T-cells percentage among the CD8-positive gated population could be observed for co-cultures with DCs loaded with apoptotic material derived from MV-treated M13 cells with respect to co-cultures with DCs loaded with apoptotic material derived from UV-treated M13 cells. | The present invention relates to the use of at least one attenuated measles virus for the manufacture of a medicament intended for treating malignant mesothelioma in an individual. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to a calculation method of input/output power at the time of drive/regenerative mode, in a power-electronics product which includes a chopper circuit and which is configured, for example, to perform a motor control.
BACKGROUND ART
[0002] For example, each of Non Patent Literature 1 and Patent Literatures 1 and 2 has proposed a motor drive device, as a device for supplying electric power of a direct-current power source to a load and for regenerating electric power of the load into the direct-current power source by using a chopper circuit.
CITATION LIST
Non Patent Literature
[0000]
Non Patent Literature 1: “220000r/min-2 kW PM Motor Drive System for Turbocharger” in Journal-D of the Institute of Electrical Engineers of Japan, Vol. 125 (2005), No. 9, pp. 854-861
Patent Literature
[0000]
Patent Literature 1: Japanese Patent No. 3278188
Patent Literature 2: Japanese Patent Application Publication No. 2008-295280
[0006] FIG. 3 shows one example of a motor drive device equipped with a direct-current power source, a chopper circuit and an inverter.
[0007] In FIG. 3 , a reference sign 10 denotes a battery, and a reference sign C 1 denotes a condenser. The condenser C 1 is connected with the battery 10 to be in parallel with the battery 10 . A reference sign 11 denotes a switching element connected through a reactor L 1 with the battery 10 to be in parallel with the battery 10 . A reference sign 12 denotes a switching element connected with the switching element 11 to be in series with the switching element 11 .
[0008] The switching element 11 is connected with a free-wheel diode (bypass diode) 13 to be in antiparallel (inverse-parallel) with the free-wheel diode 13 . The switching element 12 is connected with a free-wheel diode (bypass diode) 14 to be in antiparallel with the free-wheel diode 14 . A series combination of the switching elements 11 and 12 is connected with a condenser C 2 to be in parallel with the condenser C 2 . The condenser C 2 is connected with a series combination formed by connecting the switching elements 15 and 16 in series. The condenser C 2 is in parallel with this series combination of the switching elements 15 and 16 . The switching element 15 is connected with a free-wheel diode (bypass diode) 17 to be in antiparallel with the free-wheel diode 17 . The switching element 16 is connected with a free-wheel diode (bypass diode) 18 to be in antiparallel with the free-wheel diode 18 .
[0009] One end of a reactor L 2 is connected with a common connection point of the switching elements 15 and 16 . An inverter 19 having a three-phase bridge configuration is disposed between another end of the reactor L 2 and a negative-pole terminal of the battery 10 , and is connected with the another end of the reactor L 2 and the negative-pole terminal of the battery 10 . Three-phase output of the inverter 19 is supplied to a PM motor 20 .
[0010] A common connection point of the inverter 19 and the reactor L 2 is connected through anode and cathode of a diode D 1 with a common connection point (=point P) of the switching element 12 and the condenser C 2 .
[0011] The inverter 19 is a 120-degree-conduction current-source inverter. The inverter 19 is constituted by switching elements and free-wheel diodes (bypass diodes). The switching elements of the inverter 19 are connected with one another in the form of three-phase bridge. Each of the free-wheel diodes of the inverter 19 is connected with the corresponding switching element of the inverter 19 to be in antiparallel with this switching element.
[0012] A gate-drive circuit of the inverter 19 , a detector for sensing a voltage Vdc of the point P and a detector for sensing a current Idc flowing in the reactor L 2 are omitted from the depiction of Figures.
[0013] Operations of the device configured as above will now be explained. At first, at the time of drive mode, the switching element 11 is turned on (opened), so that electric current is applied to the reactor L 1 by a direct-current voltage which is derived from the battery 10 and which is smoothed by the condenser C 1 . Thereby, energy is stored in the reactor L 1 . Then, the switching element 11 is turned off (closed), so that the energy stored in the reactor L 1 is charged through the free-wheel diode 14 into the condenser C 2 . Thereby, a voltage of the condenser C 2 is increased.
[0014] By virtue of such a structure, the charging of condenser C 2 is possible even if a voltage on the side of condenser C 2 is high. Accordingly, the reactor L 1 , the switching element 11 , the diode 14 and the condenser C 2 constitute a first boost chopper circuit. At this time, the switching element 11 is repeatedly turned on and off in order to maintain the voltage Vdc of the condenser C 2 at a constant level. By varying a target value of this voltage control or regulation (AVR) of the condenser C 2 , a loss reduction becomes possible.
[0015] Moreover, when the switching element 15 is turned on, electric current is applied to the reactor L 2 so that energy is stored in the reactor L 2 . In this case, the drive is impossible unless the voltage Vdc of the side of condenser C 2 is higher than a voltage of the side of the reactor L 2 . Next, when the switching element 15 is turned off and the switching element 16 is turned on, a constant current flows through the switching element 16 and any two now-conducting switching elements of the inverter 19 into the reactor L 2 by means of the energy stored in the reactor L 2 . This electric current is detected by the not-shown current detector. Alternatively, a rotational speed of the PM motor 20 is detected or estimated from a waveform based on gate signals. So as to bring this electric current or rotational speed to its target value, an on/off control of the switching elements 15 and 16 is performed so that a current control (ACR) or a speed control (ASR) is performed. Moreover, by using the on/off control of the switching elements 15 and 16 , the motor 20 can be rotated by a voltage level lower than the battery voltage.
[0016] Next, operations at the time of regenerative mode will now be explained. At the time of regeneration, the PM motor 20 generates an induced voltage proportional to its rotational speed. If the induced voltage of motor becomes higher than the voltage of the side of reactor L 2 , electric current can be applied through any of the not-shown free-wheel diodes of the inverter 19 to the side of reactor L 2 . When the switching element 16 is turned on, the electric current flows in the reactor L 2 so that energy is stored in the reactor L 2 . Then, when the switching element 16 is turned off, electric current flows through the diode 17 by the energy of the reactor L 2 at first. Next, the switching element 15 is turned on after a dead time has elapsed. Thereby, electric current flows through the switching element 15 and is charged into the condenser C 2 , so that the voltage of the condenser C 2 is increased.
[0017] By virtue of such a structure, the charging of condenser C 2 is possible even if the induced voltage of the PM motor 20 is low. Accordingly, the switching elements 15 and 16 , the reactor L 2 and the condenser C 2 constitute a second boost chopper circuit. In this second boost chopper section, a current control (ACR) for maintaining electric current at a constant level, a speed control (ASR) of the PM motor 20 , or a power control (APR) for maintaining electric power at a constant level is performed. At this time, electric power is returned to the battery 10 by an increased amount of voltage of the condenser C 2 which is caused by a regeneration power derived from the second boost chopper circuit.
[0018] As a concrete procedure of retuning electric power to the battery 10 , the switching element 12 is turned on to apply electric current to the reactor L 1 . Thereby, the reactor L 1 stores energy. Then, the switching element 12 is turned off, so that electric current is applied through the free-wheel diode 13 to the reactor L 1 by the energy of the reactor L 1 .
[0019] Additionally, the positive-side voltage of the inverter 19 is introduced through the diode D 1 to the point P of the condenser C 2 as a bypass when a gate of the inverter 19 is shut off. Hence, a voltage rise of the inverter 19 can be suppressed. Therefore, damage of the respective switching elements constituting the inverter 19 can be prevented.
SUMMARY OF THE INVENTION
Technical Problem
[0020] As mentioned above, in the device of FIG. 3 , the voltage control for the voltage Vdc of the point P and the current control for the current Idc flowing in the reactor L 2 are performed. Hence, the voltage Vdc and the current Idc are already known.
[0021] However, a value of an electric current flowing in the point P (=a region to which the voltage Vdc is applied, i.e., a region producing the voltage Vdc) corresponding to an input portion of direct-current power is unknown. Also, a value of a voltage applied between the negative-pole terminal of the battery 10 and the common connection point of the inverter 19 and the reactor L 2 (=a region in which the current Idc flows) is unknown. The common connection point of the reactor L 2 and the inverter 19 corresponds to an output portion of the direct-current power. Therefore, an input/output electric power value cannot be calculated.
[0022] Therefore, in a case that an output power control or a regenerative power control is performed, in order to control precisely, it has been necessary to measure the electric power value by providing an electric-current detector at the region having the voltage Vdc or providing a voltage detector at the region having the current Idc.
[0023] The present invention solves the above problem. It is an object of the present invention to provide an electrical power control device or an electrical power calculation method in an electrical power control device, devised to calculate the input/output electrical power value without using a current detector of the input portion or a voltage detector of the output portion.
Solution to Problem
[0024] An electrical power control device comprises: a direct-current power source; a chopper circuit including a first switching element whose one end is connected with a positive-pole terminal side of the direct-current power source, a second switching element whose one end is connected with a negative-pole terminal side of the direct-current power source, wherein the first switching element and the second switching element are provided between the positive-pole terminal and the negative-pole terminal of the direct-current power source in series with the direct-current power source, and a reactor whose one end is connected with a common connection point located between another end of the first switching element and another end of the second switching element; and a load connected between another end of the reactor and the negative-pole terminal of the direct-current power source. This electrical power control device is configured to supply direct-current power of the direct-current power source to the load and is configured to regenerate the direct-current power source with direct-current power of the load by controlling the chopper circuit. In such an electrical power control device, an output voltage Vdc of the direct-current power source, a current Idc flowing in the reactor, a switching duty d 1 of the first switching element of the chopper circuit, a switching duty d 2 of the second switching element of the chopper circuit, and a dead time DT between the first switching element and the second switching element are known when a normal voltage control and/or current control is carried out. At this time, the switching duty d 1 satisfies a condition of 0≦d 1 ≦1, the switching duty d 2 satisfies a condition of 0≦d 2 ≦1, and the dead time DT satisfies a condition of 0≦DT≦1. Moreover, a relation of 1=d 1 +d 2 +DT is satisfied.
[0025] Therefore, according to the present invention, an electrical power W is determined (obtained) in the following manner by use of these known values Vdc, Idc, d 1 , d 2 and DT.
[0026] That is,
[0027] (1) In a case that only a drive of load is performed and also that the switching duty d 1 is known, the electrical power W is determined by calculating a following formula (1)
[0000] W=Vdc·d 1 ·Idc (1)
[0028] (2) In a case that only a power regeneration from load is performed and also that the switching duty d 2 is known, the electrical power W is determined by calculating a following formula (2).
[0000] W=Vdc ·(1− d 2 )· Idc (2)
[0029] (3) In a case that the drive of load is performed and also that the switching duty d 2 is known, the electrical power W is determined by calculating a following formula (3)
[0000] W=Vdc ·(1− d 2 −DT )· Idc (3)
[0030] (4) In a case that electrical power is regenerated from load and also that the switching duty d 1 is known, the electrical power W is determined by calculating a following formula (4).
[0000] W=Vdc ·( d 1 +DT )· Idc (4)
[0031] (5) In a case that the drive of load and the regeneration from load are performed and also that the switching duty d 1 and the switching duty d 2 are known, the electrical power W is determined by calculating any one of the above formulas (1) to (4).
[0032] (6) Furthermore, an internal loss by the chopper circuit is calculated, and thereby, an electrical-power rate (ratio) n between input and output of the chopper circuit is obtained based on the internal loss. Then, from the electrical-power rate n and the electrical power W obtained by one of the above formulas (1) to (4); an electrical power W′ adjusted in consideration of an equipment efficiency is determined by calculating a following formula (5).
[0000] W′=n·W (5)
[0033] According to the above structures, an electrical-power value can be calculated without providing a current detector for detecting electric current flowing in the direct-current power source (the region to which the voltage Vdc is applied) and a voltage detector for detecting voltage applied to the another end of the reactor (voltage of the region in which the current Idc flows).
Advantageous Effects of Invention
[0034] (1) According to the inventions as claimed in claims 1 to 8 , an electrical-power value can be calculated without providing a current detector for detecting electric current flowing in the direct-current power source and without providing a voltage detector for detecting voltage applied to the another end of the reactor.
[0035] (2) Moreover, by using the calculated electrical-power value, a drive (power-running) power control or a regenerative power control can be accurately attained without providing the current detector or the voltage detector.
BRIEF EXPLANATION OF DRAWINGS
[0036] FIG. 1 A configuration view of an electrical power control device to which the present invention is applied.
[0037] FIG. 2 A main circuit diagram showing seventh to ninth examples according to the present invention.
[0038] FIG. 3 A circuit diagram showing one example of a motor drive device to which the present invention is applied.
DESCRIPTION OF EMBODIMENTS
[0039] Hereinafter, embodiments according to the present invention will be explained referring to the drawings. However, the present invention is not limited to examples of the following embodiments. FIG. 1 shows a configuration of an electrical power control device to which the present invention is applied. A reference sign 1 denotes a direct-current power source (DC power source), for example, constituted by a circuit ranging from the point P (to which the voltage Vdc is applied) to the battery 10 , i.e., constituted by the battery 10 , the condensers C 1 and C 2 , the reactor L 1 , the switching elements 11 and 12 , and the free-wheel diodes 13 and 14 in FIG. 3 .
[0040] This direct-current power source 1 according to the present invention is not limited to the circuit shown by FIG. 3 , and may be a direct-current power source having a thyristor-rectifier bridge circuit or a battery having the voltage value Vdc.
[0041] A reference sign 2 denotes a chopper circuit, for example, including the switching elements 15 and 16 , the free-wheel diodes 17 and 18 and the reactor L 2 in FIG. 3 .
[0042] A reference sign 3 denotes a control section including a function for calculating an electric power W. For example, this function of the control section 3 calculates the electric power W by using the above formulas (1) to (4) on the basis of the voltage Vdc of point P of FIG. 3 , the electric current Idc flowing in the reactor L 2 , a switching duty d 1 of a first switching element (the switching element 15 of FIG. 3 ) of the chopper circuit 2 , a switching duty d 2 of a second switching element (the switching element 16 of FIG. 3 ) of the chopper circuit 2 , and the dead time DT between the first switching element and the second switching element. The switching duty d 1 satisfies a condition of 0≦d 1 ≦1. The switching duty d 2 satisfies a condition of 0≦d 2 ≦1. The dead time DT satisfies a condition of 0≦DT≦1.
[0043] Moreover, the control section 3 includes a function for calculating an electric power W′ adjusted by taking the equipment efficiency into consideration. This function of the control section 3 calculates the electric power W′, by calculating an internal loss of the chopper circuit 2 and calculating the above formula (5) from the electric power W and a power ratio (rate) n of input and output of chopper circuit based on the internal loss.
[0044] Moreover, the control section 3 includes a function for performing a control for supplying direct-current power of the direct-current power source 1 to the direct-current load 4 and a (regenerative) control for returning direct-current power of the direct-current load 4 to the direct-current power source 1 by controlling the chopper circuit 2 .
[0045] The direct-current load 4 , for example in FIG. 3 , includes the inverter 19 for converting direct-current power into alternating-current power, and the PM motor 20 connected with an alternating-current side of the inverter 19 .
[0046] The voltage Vdc, the current Idc, the switching duty (duty time) d 1 , the switching duty (duty time) d 2 and the dead time DT are known (1=d 1 +d 2 +DT) under the normal voltage control or current control. Means for detecting these values are omitted from the depiction of FIG. 1 .
[0047] Next, concrete examples will now be explained in each of which the present invention is applied to the motor drive device of FIG. 3 . In the following examples, operations of the switching elements 11 , 12 , 15 and 16 at the time of drive mode of the PM motor 20 and at the time of regenerative mode of electric power of the PM motor 20 are basically as mentioned above.
First Example
[0048] In a first example, the present invention is applied to a case where only the drive of the PM motor 20 is performed in the circuit of FIG. 3 and where the switching duty d 1 of the switching element 15 is known. It is noted that the switching duty d 1 is represented by duty=A/B, wherein A denotes a turn-on time of the switching element and wherein B denotes one period of ON-OFF operation.
[0049] At this time, the switching elements 16 and 12 whose on-off controls are performed during the regenerative motion are unnecessary. Hence, the combination of the switching element 16 and the diode 18 may be replaced with only the diode 18 , and the combination of the switching element 12 and the diode 14 may be replaced with only the diode 14 .
[0050] A value of the current flowing in the point P (=the region to which the voltage Vdc is applied) of FIG. 3 is equal to d 1 ·Idc. Accordingly, the control section 3 of FIG. 1 calculates the value of electric power W by the following formula (1).
[0000] W=Vdc·d 1 ·Idc (1)
Second Example
[0051] In a second example, the present invention is applied to a case where only the regeneration of electric power of the PM motor 20 (regenerative mode by the PM motor 20 ) is performed in the circuit of FIG. 3 and where the switching duty d 2 of the switching element 16 is known.
[0052] At this time, the switching elements 15 and 11 whose on-off controls are performed during the drive motion are unnecessary. Hence, the combination of the switching element 15 and the diode 17 may be replaced with only the diode 17 , and the combination of the switching element 11 and the diode 13 may be replaced with only the diode 13 .
[0053] During the regeneration of electric power, a regeneration current flows through the switching element 15 or the diode 17 into the point P (the region to which the voltage Vdc is applied) when the switching element 16 is in OFF state. Accordingly, a value of this regeneration current is equal to a product (multiplication) of the current Idc and a turn-off time (1−d 2 ) of the switching element 16 .
[0054] Therefore, the control section 3 of FIG. 1 calculates the value of electric power W by the following formula (2).
[0000] W=Vdc ·(1 −d 2 )· Idc (2)
Third Example
[0055] In a third example, the present invention is applied to a case where the drive of the PM motor 20 is performed in the circuit of FIG. 3 and where the switching duty d 2 of the switching element 16 is known.
[0056] During the drive of the PM motor 20 , electric current flows from the point P when the switching element 15 is in ON state. This turn-on time of the switching element 15 is represented by (1−d 2 −DT) using the turn-off time (1−d 2 ) of the switching element 16 and the dead time DT. Accordingly, a value of the current flowing in the point P is equal to (1−d 2 −DT)·Idc. Therefore, the control section 3 of FIG. 1 calculates the value of electric power W by the following formula (3).
[0000] W=Vdc ·(1− d 2 −DT )· Idc (3)
Fourth Example
[0057] In a fourth example, the present invention is applied to a case where the regeneration of electric power of the PM motor 20 is performed in the circuit of FIG. 3 and where the switching duty d 1 of the switching element 15 is known.
[0058] During the electric-power regeneration, regenerative current flows in the point P through the switching element 15 turned on when the switching element 16 is in OFF state. This turn-off time of the switching element 16 is represented by a sum (d 1 +DT) of the switching duty d 1 of the switching element 15 and the dead time DT. Accordingly, a value of the regenerative current flowing in the point P is equal to a product (multiplication) of the current Idc and the turn-off time (d 1 +DT) of the switching element 16 .
[0059] Therefore, the control section 3 of FIG. 1 calculates the value of electric power W by the following formula (4).
[0000] W=Vdc ·( d 1 +DT )· Idc (4)
Fifth Example
[0060] In a fifth example, the present invention is applied to a case where the drive and the electric-power regeneration of the PM motor 20 are performed in the circuit of FIG. 3 and where the switching duty d 1 of the switching element 15 and the switching duty d 2 of the switching element 16 are known.
[0061] The control section 3 of FIG. 1 calculates the value of electric power W by one of the above formulas (1) to (4) of the first to fourth examples.
Sixth Example
[0062] The value of electric power which is calculated in the first to fifth examples is the electric-power value of the point P (the region to which the voltage Vdc is applied) of FIG. 3 . Hence, in a case of actual equipment (device), this electric-power value of the point P deviates from an electric-power value of input/output portion of the chopper circuit due to an internal loss. Therefore, in this example, the internal loss is calculated. In the case that a rate of electric power of the input/output portion relative to the point P of FIG. 3 is known as n, an accurate electric power W′ of the input/output portion can be obtained by calculating the following formula (5) using the electric power W calculated in the first to fifth examples.
[0000] W′=n·W (5)
[0063] It is noted that an efficiency η of the equipment can be used as this rate n.
Seventh Example
[0064] In a seventh example, a power control or power regulation (APR) including a control loop as shown in FIG. 2 is applied to the switching elements 15 and 16 of FIG. 3 which have performed the current control (ACR) beforehand, on the basis of the electric-power value W (W′) calculated in the first to sixth examples. Thereby, the power-running (driving) control and the power-regenerating control can be attained without providing additional current/voltage detector.
[0065] FIG. 2 extracts a part from FIG. 3 , and shows components same as those of FIG. 3 with same reference signs. In FIG. 2 , a reference sign 30 denotes an electric-power control section for performing the power control (APR) on the basis of an electric-power command value W cmd and the electric-power value W (W′) calculated in the first to sixth examples.
[0066] A reference sign 40 denotes an electric-current control section for performing the current control (ACR) on the basis of an electric-current command value Idc cmd and the electric-current detection value Idc.
Eighth Example
[0067] An eighth example is done under the same case as the third example (i.e., under the case where the drive is performed in FIG. 3 and where only the switching duty d 2 of the switching element 16 is known) and also under the case of the seventh example. In the eighth example, the dead time DT of the above formula (3) is ignored. That is, the electric-power value W which is a control target is calculated by a following formula (6).
[0000] W=Vdc ·(1 −d 2 )· Idc (6)
[0068] In this case, an error in the control is caused by an influence of the dead time. Therefore, the electric-power command value W cmd is modified into W′ cmd as shown by a following formula (7). Accordingly, the output electric-power control can be accurately performed because a correction depending on the dead time is added.
[0000] W′ cmd =W cmd +DT·Vdc·Idc (7)
Ninth Example
[0069] A ninth example is done under the same case as the fourth example (i.e., under the case where the regeneration is performed in FIG. 3 and where only the switching duty d 1 of the switching element 15 is known) and also under the case of the seventh example. In the ninth example, the dead time DT of the above formula (4) is ignored. That is, the electric-power value W which is a control target is calculated by a following formula (8).
[0000] W=Vdc·d 1 ·Idc (8)
[0070] In this case, an error in the control is caused by an influence of the dead time. Therefore, the electric-power command value W cmd is modified into W′ cmd as shown by a following formula (9). Accordingly, the output electric-power control can be accurately performed because a correction depending on the dead time is added.
[0000] W′ cmd =W cmd −DT·Vdc·Idc (9)
LIST OF REFERENCE SIGNS
[0000]
1 —Direct-current power source
2 —Chopper circuit
3 —Control section
4 —Direct-current load
10 —Battery
11 , 12 , 15 , 16 —Switching element
13 , 14 , 17 , 18 —Free-wheel diode
19 —Inverter
20 —PM motor
30 —Electric-current control section
40 —Electric-power control section
C 1 , C 2 —Condenser
L 1 , L 2 —Reactor
D 1 —Diode | A motor drive device including a battery 10 ; switching elements 15 and 16 which are connected in series with a condenser C 2 having a voltage Vdc resulting from an increase action of battery voltage and which are operated in a chopper control; a reactor L 2 whose one end is connected with a common connection point of the switching elements 15 and 16 ; and an inverter 19 for driving a PM motor 20 which is connected between another end of the reactor L 2 and a negative-pole terminal of the battery 10 . In such a motor drive device, an electrical power W is determined based on the voltage Vdc of positive-side point P of the condenser C 2 , a current Idc flowing in the reactor L 2 , and a switching duty d 1 of the switching element 15 which satisfies a condition of 0≦d 1 ≦1, i.e., is determined by calculating Vdc·d 1 ·Idc. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the invention:
The present invention relates to a method and device for testing analog and mixed-signal circuits.
In the present disclosure and in the appended claims, the term "mixed signal circuit" is intended to designate a circuit including both analog and digital circuitry.
2. Brief description of the prior art:
Due to the development of integrating technologies and the market requirements, the trend of designing mixed-signal ASICs (Application-Specific Integrated Circuits) has significantly increased. Analog testing is a challenging task and is considered as one of the most important problems in analog and mixed-signal ASIC design. The specifications of analog circuits are usually very large which results in long testing time and poor fault coverage. A dedicated test equipment is also required. Furthermore, it is very difficult to establish universal fault models equivalent to the so called stuck-at models in digital circuits.
A fault can be either catastrophic or parametric. Catastrophic faults result in complete absence of the desired function. On the other hand, parametric faults result in functional circuit but with degraded performance. Catastrophic faults are easier to test, but when the complexity of the CUT (Circuit Under Test) increases they cause many problems. Parametric faults are the most important and hard to test faults. It should be pointed out that most of the existing test methods address only the catastrophic faults.
Known methods for testing analog blocks comprise functional (or parametric) testing, DC (Direct Current) testing, and power supply current (I DDQ ) monitoring. Functional (or parametric) testing has been described in the following four articles:
[1] C.-L Wey, "Built-In Self-Test Structure for Analog Circuit Fault Diagnosis", IEEE Transactions on Instrumentation and Measurement, 39(3), 1990, pp. 517-521.
[2] L. Milor et al., "Optimal Test Set Design for Analog Circuits", IEEE ICCAD, 1990, pp. 294-297.
[3] P. P. Fasang, D. Mulins and T. Wong, "Design for Testability for Mixed Analog/Digital ASICs", IEEE Custom Integrated Circuit Conf., 1988, pp. 16.5.1-16.5.4.
[4] K. D. Wagner and T. W. Williams, "Design for Testability of Mixed signal Integrated Circuits", IEEE Int. Test Conf., 1988, pp. 823-829.
DC testing has been suggested in the following two articles:
[5] M. J. Marlett and J. A. Abraham, "DC IATP-An Iterative Analog Circuit Test Generation Program for Generating Single Pattern Tests", IEEE Int. Test Conf., 1988, pp. 839-844.
[6] G. Devarayanadurg and M. Soma, "Analytical Fault Modelling and Static Test Generation for Analog ICs", IEEE ICCAD, 1994, pp. 44-47.
Power-supply current (I DDQ ) monitoring is discussed in the following two publications:
[7] G. Gielen, Z. Wang and W. Sansen, "Fault Detection and Input Stimulus Determination for the Testing of Analog Integrated Circuits Based on Power-Supply Current Monitoring", IEEE ICCAD, 1994, pp. 495-498.
[8] P. Nigh and W. Maly, "Test Generation for Current Testing", IEEE Design & Test of Computers, Vol. 7, No. 2, 1990, pp. 26-38.
Various designs for testability (DFT) rules have been used in conjunction with the above mentioned test methods to ease the test problem (articles [3] and [4]). These techniques are employed during the design stage to increase the controllability and observability and to facilitate the test task. Some of these techniques for digital testing have been the subject of U.S. Pat. No. 4,513,418 (P. H. Bardell et al.) issued on Apr. 23, 1985 for an invention entitled "Simultaneous Self Testing System" and U.S. Pat. No. 4,749,947 granted to T. R. Gheewala on Jun. 7, 1988 for an invention entitled "Cross-Check Test Structure for Testing Integrated Circuits".
The effectiveness of the above methods depends strongly on the selection of suitable test vectors. Also, they need a large number of test vectors to validly testing the functionality of the CUT. When the complexity of the CUT increases, the problem of determining optimal test vectors becomes critical. Furthermore, the process of choosing a suitable form of excitation signals and evaluation of the results is time consuming. BIST (Built-In Self-Test) strategies based of above methods require the use of specialized input stimuli generation and output evaluation hardware which introduce significant area overhead.
OBJECTS OF THE INVENTION
An object of the present invention is therefore to overcome the above discussed drawbacks of the prior art.
Another object of the present invention is to overcome the above discussed drawbacks of the prior art by providing a very efficient method and device for testing analog and mixed-signal circuits, in which the CUT is rearranged into a circuit easier to test.
A further object of the present invention is to provide a method and device for testing analog and mixed-signal circuits, in which the CUT is inserted into an oscillation circuit.
SUMMARY OF THE INVENTION
More particularly, in accordance with the present invention, there is provided an oscillation-based test method for testing an at least partially analog circuit, comprising the steps of:
dividing the at least partially analog circuit into building blocks each having a given structure;
inserting each building block under test into an oscillator circuit to produce an output signal having an oscillation frequency related to the structure of the building block under test;
measuring the oscillation frequency of the output signal; and
detecting a fault in the building block under test when the measured oscillation frequency deviates from a given, nominal frequency.
By inserting the building block under test into an oscillator circuit producing an output signal having an oscillation frequency related to the structure of the building block, a catastrophic or parametric fault in the building block can be easily detected by simply sensing a deviation of the measured oscillation frequency from the above mentioned given, nominal frequency.
In accordance with preferred embodiments of the oscillation-based test method of the invention:
the measuring step comprises converting the oscillation frequency of the output signal into a frequency representative number, and the fault detecting step comprises (a) comparing the frequency representative number to a given, nominal number, and (c) detecting a fault in the building block under test when the frequency representative number deviates from the given, nominal number; and
the inserting step comprises combining at least two building blocks to form the oscillator circuit.
The present invention is also concerned with a device for testing an at least partially analog circuit divided into building blocks each having a given structure and inserted into an oscillator circuit to produce an output signal having an oscillation frequency related to the structure of the building block, comprising:
means for measuring the oscillation frequency of the output signal; and
means for detecting a fault in the building block under test when the measured oscillation frequency deviates from a given, nominal frequency.
In accordance with preferred embodiments of the device according to the invention:
the measuring means comprises a frequency-to-number converter for converting the oscillation frequency of the output signal into a frequency representative number, and the fault detecting means comprises a control logic for comparing the frequency representative number to a given, nominal number and for detecting a fault in the building block under test when the frequency representative number deviates from the given, nominal number;
the frequency-to-number converter comprises a zero crossing detector for detecting passages of the output signal by a zero amplitude to produce a square wave clock signal including a series of pulses, and a counter for counting the pulses of the square wave clock signal to produce the frequency representative number;
the test device further comprises an additional circuitry, and means for connecting the additional circuitry to the building block under test to form an oscillator circuit, wherein these connecting means comprises means for successively connecting the additional circuitry to different building blocks in order to test the different buildings blocks with the same additional circuitry.
The objects, advantages and other features of the present invention will become more apparent upon reading of the following non restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings:
FIG. 1 is a schematic block diagram illustrating an oscillation-based built-in self test (OBIST) embodying the test method of the present invention, for analog and mixed-signal circuits;
FIG. 2 is a schematic block diagram of a frequency-to-number converter used in the oscillation-based test method of FIG. 1;
FIG. 3 is a schematic block diagram illustrating an embodiment of the oscillation-based test method in accordance with the present invention, to improve the testability of analog and mixed-signal circuits;
FIG. 4a is a schematic block diagram illustrating a first mathematical approach for inserting a CUT into an oscillator circuit using a negative feedback loop;
FIG. 4b is a schematic block diagram illustrating a second mathematical approach for inserting a CUT into an oscillator circuit using a positive feedback loop;
FIG. 5 is a schematic block diagram showing a DFT technique for inserting an operational amplifier (CUT) into an oscillator circuit in which the oscillation frequency is related to the internal structure of the operational amplifier;
FIG. 6 is a schematic block diagram showing a DFT technique for inserting two operational amplifiers (CUT) into an oscillator circuit whose oscillation frequency depends on the internal structure of the two operational amplifiers under test;
FIG. 7 is a schematic block diagram showing a DFT technique for inserting a chain of operational amplifiers (CUT) into an oscillator circuit;
FIG. 8 is a schematic block diagram showing a DFT technique for inserting a high-Q band-pass filter into an oscillator circuit by means of a positive feedback loop including a zero-crossing detector;
FIG. 9 is a diagram showing the implementation of the method of FIG. 8 to a second order active band-pass filter;
FIG. 10 is a schematic block diagram of a dual-slope analog-to-digital converter; and
FIG. 11 is a schematic block diagram of an oscillation-based test structure for inserting the analog port of the dual-slope analog-to-digital converter of FIG. 10 into an oscillator circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description will show how the oscillation-based testing method in accordance with the present invention can be applied to common integrated analog or mixed-signals circuits such as embedded operational amplifiers, filters, and analog-to-digital converters. However, it should be kept in mind that the method and device in accordance with the present invention can be easily applied to other types of circuits such as functional analog circuits and non integrated circuits.
More specifically, FIG. 1 illustrates a basic BIST structure suitable for use in the oscillation-based testing method according to the invention.
Referring to FIG. 1, the method first comprises the step of dividing the CUT 10 into building blocks such as 11. The CUT is then in the test mode.
The BIST structure 12 comprises some additional circuitry 13 integrated to the CUT 10 and to be connected to each building block 11 to form with this building block 11 an oscillator circuit producing an output signal having an oscillation frequency related to the structure of the building block 11 under test. Examples of additional circuitry 13 suitable to form with the building blocks 11 oscillator circuits will be described in the following description.
The BIST structure 12 of FIG. 1 further comprises an analog multiplexer 14, a frequency-to-number converter 15, and a control logic 16. The analog multiplexer 14 is connected to the different outputs 17 of the building blocks 11 to successively select these outputs 17 under the control of the control logic 16. The oscillation frequency of the signal at the output 17 of the building block 11 being selected by the analog multiplexer 14 is converted to a frequency representative number by the frequency-to-number converter 15. The control logic 16 then compares the frequency representative number from the frequency-to-number converter 15 to a given, nominal number corresponding a nominal frequency of oscillation of the so formed oscillator circuit, and detects a fault in the building block 11 under test when the frequency representative number deviates the given, nominal number. When the frequency representative number corresponds to the given, nominal number, the control logic 16 delivers a "pass" signal indicating that the building block 11 under test is fully functional. On the contrary, when the frequency representative number from the converter 15 deviates from the given, nominal number, the control logic 16 delivers a "fail" signal indicating that the building block 11 of the CUT 10 is faulty.
To verify the functionality of the BIST structure 12 itself, the circuitry of the BIST structure 12 is tested during a self-test phase before testing the CUT 10.
FIG. 2 is a schematic block diagram of the frequency-to-number converter 15 of FIG. 1.
The frequency-to-number converter 15 can be implemented using various techniques such as a phase-locked loop (PLL) or any type of FM (Frequency Modulation) demodulator. The preferred embodiment of FIG. 2 uses a simple and fully digital circuit capable of converting each frequency to a related number. The oscillation frequency f OSC of the selected output 17 is supplied by the analog multiplexer 14 to a zero crossing detector 19. The zero crossing detector 19 detects passages of the oscillation output signal by a zero amplitude to produce on its output 20 a square wave clock signal including a series of pulses and applied to a counter 21. The counter 21 is enabled by the high signal level of a square wave reference frequency f REF . Therefore, during the high signal level of the square wave reference frequency f REF , the counter 21 counts the pulses from the output 20 while during its low signal level the counter 21 is disabled and stops counting. The counter 21 delivers an output digital count value on a parallel output 22. The output count value from the parallel output 22 of the counter 21 is representative of a number related to the input frequency f OSC coming from the output 17 of a building block 11 under test, and can be evaluated by the control logic 16. After evaluation of the output frequency representative number from the counter 21, the control logic 16 resets the counter 21 through the input 23 thereof. Those of ordinary skill in the art will appreciate that an accurate frequency-to-number conversion is obtained; the accuracy of the frequency-to-number converter 15 is determined by the reference frequency f REF signal and the number of bits of the parallel output 22 of the counter 21. More specifically, the digital output of the counter 21 is given by the following relation: ##EQU1##
In fact, the oscillation frequency f OSC is divided by the reference frequency f REF to obtain the number B 1:n . This technique produces a very good accuracy and satisfies the requirement of the intended application.
In the example of FIG. 3, the oscillation-based test method is used to facilitate the test problem. The test structure 12 then comprises the additional circuitry 13, the analog multiplexer 14 and the control logic 16.
Again, the additional circuitry 13 is to be connected to each building block 11 to form with this building block 11 an oscillator circuit producing an output signal having an oscillation frequency related to the structure of the building block 11 under test. The analog multiplexer 14 is connected to the different outputs 17 of the building blocks 11 to successively select these outputs 17 under the control of the logic 16. The oscillation frequency f OSC at the output 17 of the building block 11 being selected by the analog multiplexer 14 is then supplied to an output 18 of the test structure 12. The oscillation frequency f OSC from the output 18 of the BIST structure 12 is evaluated externally using a test equipment (not shown). The embodiment of FIG. 3 enables an important simplification of the control logic 16 and more generally of the test structure 12. In this case, since the oscillation frequency is externally evaluated, the voltage level of the oscillation frequency signal from the output 17 of the building block 11 being tested can also be evaluated to improve the fault coverage.
For each type of building block 11, various techniques can be easily found to insert the building block into an oscillator circuit. A mathematical approach is to convert the transfer function of the CUT to the transfer function of an oscillator, and then to modify the internal circuitry of the CUT to obtain the new transfer function. For example, second order active filters can be converted to oscillators by making the quality factor Q F infinite, which means that the poles are on the jω axis. A more general technique consists of performing some mathematical operations to obtain the oscillator's transfer function.
In the example of FIG. 4a, a negative feedback loop 24 including a transfer function F H and and adder 25 is added to the transfer function F CUT g of the building block 11 to achieve the transfer function F OSC of an oscillator. The transfer functional F OSC of FIG. 4a can then be expressed as follows: ##EQU2## Thus F H is given by the following relation: ##EQU3##
Another approach is illustrated in FIG. 4b. The approach of FIG. 4b consists of adding to the transfer function Fcr of the building block 11 a positive feedback loop 26 including a transfer function F H and an adder 27, and of trying to satisfy the condition of oscillation by appropriately selecting the parameters of the transfer function F H . In that case, the new transfer function is given by the following relation: ##EQU4## and the condition for the feedback loop to cause sinusoidal oscillations of frequency ω o is that:
|F.sub.CUT (jω.sub.o)||F.sub.H (jω.sub.o)|≧1
and the phase of the signal φ around the loop is such that:
φ.sub.A +φ.sub.B =0°
where φ A and φ B are the phase shifts associated with the CUT and feedback network, respectively.
It is further possible to add both positive and negative feedback loops and then to force the resulting circuit to oscillate.
A further possible solution is to employ heuristic circuit techniques to obtain an oscillator from the original building block 11 of the CUT.
Some examples of application of the oscillation-based test method in accordance with the present invention will now be described. These examples are given for the purpose of exemplification only and should not be interpreted as limiting the scope of the invention.
FIG. 5
The operational amplifiers are the blocks most frequently encountered in analog and mixed-signal circuits. For analog functional blocks with embedded operational amplifiers, the test procedure will be easier and the fault coverage will be higher if it can be assumed that the operational amplifiers are not faulty. Therefore, the interest of developing an efficient technique to test operational amplifiers is obvious.
In FIG. 5, an operational amplifier 28 is tested. To perform the test, the operational amplifier 28 is inserted into a simple operational-amplifier-based oscillator circuit 29. In this particular case, the additional circuitry 13 comprises two transistors 30 and 31, a resistor 32 and a capacitor 33, forming part of the integrated circuit and connectable as shown in FIG. 5 to the operational amplifier 28 through switching elements 34-36 for the duration of the test. After the test, the switching elements are opened to disconnect the operational amplifier 28 from the additional circuitry 13. The switching elements 34-36 are semiconductor elements such as transistors or the like which, in the closed state of the switching elements 34-36 have a low resistance to minimize performance degradation. The area overhead due to these switching elements 34-36 on the integrated circuit (CUT) being tested is very, very small.
The oscillation frequency of the circuit of FIG. 5 depends on the value of the internal dominant pole and the DC open loop gain of the operational amplifier 28, the resistance R of the resistor 32, and the capacitance C of the capacitor 33. The transistors 30 and 31 are used as active resistors to introduce a positive feedback and are adjusted to guarantee a sustained oscillation.
The additional circuitry 13 is used for all the operational amplifiers of the chip (CUT 10) whereby the area overhead is very small. The operational amplifiers are successively connected to, that is inserted in the oscillator circuitry of FIG. 5 through the above mentioned switching elements and, as described in the foregoing description, the oscillation frequency is evaluated to determine whether the operational amplifier is faulty or not.
Simulations have shown that the majority of catastrophic faults result in a loss of oscillation.
FIG. 6
Another oscillator circuit 36 suitable for simultaneously testing two operational amplifiers 37 and 38 is illustrated in FIG. 6 and has been described in the article of R. Senani entitled "Simple Sinusoidal Oscillator Using Opamp Compensation Poles", published in Electronic Letters, Vol. 29, No. 5, 1993, pp. 452-453. The oscillator circuit 36 of FIG. 6 is a simple sinusoidal oscillator using the compensation poles of the operational amplifiers 37 and 38 and, therefore, the oscillation frequency is tightly related to the internal structure of these operational amplifiers 37 and 38. The additional circuitry 13 simply comprises a resistor 39 and a capacitor 40 whereby the area overhead on the integrated circuit is smaller than in the previous circuit illustrated in FIG. 5. The connections between the operational amplifiers 37 and 38, the resistor 39 and the capacitor 40 are clearly shown in FIG. 6 and can be established through switching elements (not shown) as described with reference to FIG. 5 for the duration of the test. The condition of oscillation and the frequency of oscillation f OSC are ##EQU5## respectively, where ω t1 is the GBW (unity-gain bandwidth) of the first operational amplifier 37, τ=RC and f ti =ω ti /2II.
Experiments with the oscillators of FIGS. 5 and 6 have proved that both catastrophic and parametric faults manifest as a deviation of the oscillation frequency from the given, nominal frequency and, therefore, can be easily detected.
FIG. 7
An approach to speed up the test process is to place all the operational amplifiers 46 of a given CUT into a chain to construct an oscillator circuit 41 as illustrated in FIG. 7. The additional circuitry 13 then simply comprises two transistors 42 and 43, a resistor 44, and a capacitor 45 interconnected with the chain of operational amplifiers 46 as illustrated in FIG. 7. With the circuit of FIG. 7, the test time is significantly reduced but the fault coverage will be smaller. However, a hard fault in any of the operational amplifiers 46 deviates the oscillation frequency from its nominal value and, therefore, is detectable.
FIG. 8
In this example, a high-Q band-pass filter 47 is converted to an oscillator using a quite simple technique. The basic principle of the example of FIG. 8 is to place the band-pass filter 47 in a positive-feedback loop 50 including a zero-crossing detector 48 or a hard limiter. The wide band noise at the input 49 of the band-pass filter 47 is filtered and only a sine wave signal whose frequency is equal to the center frequency of the filter is passed. The zero-crossing detector 48 delivers on its output 51 a square wave whose frequency is ω 0 . This square wave is applied to the input 49 of the band-pass filter 47 and this filter 47 generates a sine wave at the fundamental frequency ω 0 . The zero-crossing detector 48 introduces a very high gain to guarantee a sustained oscillation. Again, the zero-crossing detector 48 can be connected to the band-pass filter 47 through switching elements 52 and 53 for the duration of the test.
FIG. 9
This figure shows the implementation of the method of FIG. 8 for a second order active band-pass filter which has a center frequency of approximately 25 kHz.
Experimentation of the circuits of FIGS. 8 and 9 have demonstrated that both catastrophic and parametric faults can be detected.
To enable the use of the method of FIGS. 8 and 9, other filter circuits can be converted to a band-pass filter using mathematical transformations as explained earlier for the conversion of a given circuit to an oscillator. Also, the output of a low-pass and high-pass filter may be added together to obtain a band-pass output. The input of a notch filter may be subtracted from its output to construct a band-pass filter. State variable filters can be tested using their band-pass output. It should also be noted that other techniques are available to construct an oscillator from a filter.
FIGS. 10 and 11
FIG. 10 illustrates a dual-slope analog-to-digital converter 53. The analog part of the converter 53 comprises an integrator 54 and a comparator 55. The integrator 54 comprises an operational amplifier 56, a resistor 57 having a resistance R, and a capacitor 58 having a capacitance C. The comparator 55 comprises an operational amplifier 59. The property of integrating the input signal 63 by means of the integrator 54 makes the converter 53 immune to noise. The converter 53 further comprises a control logic 60 controlling an input switch 61 through which the input analog signal 63 is supplied to one terminal of the resistor 57, and serving as an interface between the output of the operational amplifier 59 and an output register 62 producing the digital version 64 of the input signal 63. The different components of the analog-to-digital converter 53 are interconnected as shown in FIG. 10. The structure of the analog-to-digital converter 53 is well known to those of ordinary skill in the art and accordingly will not be further described.
FIG. 11 presents a test solution for the analog-to-digital converter of FIG. 10, based on the test method in accordance with the present invention. At the first test phase, the existing integrator 54 and comparator 55 are rearranged to a multivibrator using additional resistors R a and R b , and switching elements 65 and 66 controllable through the control logic 60. The different components are interconnected as illustrated in FIG. 11. The oscillation frequency and the oscillation condition of the multivibrator circuit of FIG. 11 are respectively given by the following relations: ##EQU6## The above equation assumes that the operational amplifiers are ideal and does not express the effect of the internal characteristics of these operational amplifiers. These effects can be neglected when the operational amplifiers are fault-free, but when there is a fault in the operational amplifiers they influence the oscillation frequency.
The oscillation frequency f OSC is converted to a number by the existing counter (output register 62). The obtained number is compared with the given, nominal number to verify whether there is a fault in the structure of the analog-to-digital converter 53.
At the second test phase, the analog-to-digital converter 53 is rearranged into a functional mode in which a voltage reference -V REF is supplied to the integrator 54 through the switch 61, and converted to digital. The digital number obtained is compared with a second, given test signature number to verify the functionality of the digital part of the analog-to-digital converter 53 and also of value of the signal -V REF . The operation is directed by the control logic. All the internal blocks of the analog-to digital converter 53 contribute to the test structure and are therefore tested in a single operation. The simplicity and efficiency of the test architecture of FIG. 11 is obvious. Oversampled analog-to-digital converters have analog components similar to those of FIG. 10; therefore, the same test technique can be applied to them.
The example of FIGS. 10 and 11 proposes an approach which consists of combining different building blocks such as Schmitt triggers, comparators, integrators and amplifiers to construct an oscillator and thereby enable testing in accordance with the resent invention.
Other types of building blocks can also be placed in an oscillator using circuit techniques which are well known to those of ordinary skill in the art of integrated oscillators. Since proposing all the circuit techniques available to convert building blocks to an oscillator is not the main objective of the invention, the present disclosure will be limited to the examples of FIGS. 4a, 4b, and 5-11 which are believed to be sufficient to allow integrated circuit designers to achieve the technique and assure the testability of analog circuits.
Although the present invention has been applied to some specific electronic circuits and some preferred embodiments thereof have been described, it should be understood that many modifications and changes may be made in the illustrated embodiments without departing from the spirit and scope of the invention and that the method is not limited to the presented building blocks. | The oscillation-based test method and device is applied to at least partially analog circuits. The at least partially analog circuit is first divided into building blocks each having a given structure. Each building block is then inserted into an oscillator circuit to produce an output signal having an oscillation frequency related to the structure of the building block under test. The oscillation frequency is then measured and a fault in the building block under test is detected when the measured oscillation frequency deviates from a given, nominal frequency. Experiments have demonstrated that the frequency deviation enables the detection of catastrophic and/or parametric faults, and ensures a high fault coverage. In this new time-domain test method, a single output frequency is evaluated for each building block whereby the test duration is very short. These characteristics make the test strategy very attractive for wafer-probe testing as well as final production testing. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of U.S. application Ser. No. 10/004,316 filed Oct. 30, 2001 and entitled “Slant Entry Well System and Method”.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates generally to systems and methods for the recovery of subterranean resources and, more particularly, to a slant entry well system and method.
BACKGROUND OF THE INVENTION
[0003] Subterranean deposits of coal contain substantial quantities of entrained methane gas. Limited production and use of methane gas from coal deposits has occurred for many years. Substantial obstacles, however, have frustrated more extensive development and use of methane gas deposits in coal seams. The foremost problem in producing methane gas from coal seams is that while coal seams may extend over large areas of up to several thousand acres, the coal seams are fairly shallow in depth, varying from a few inches to several meters. Thus, while the coal seams are often relatively near the surface, vertical wells drilled into the coal deposits for obtaining methane gas can only drain a fairly small radius around the coal deposits. Further, coal deposits are not amenable to pressure fracturing and other methods often used for increasing methane gas production from rock formations. As a result, once the gas easily drained from a vertical well bore in a coal seam is produced, further production is limited in volume. Additionally, coal seams are often associated with subterranean water, which must be drained from the coal seam in order to produce the methane.
[0004] Horizontal drilling patterns have been tried in order to extend the amount of coal seams exposed to a drill bore for gas extraction. Such horizontal drilling techniques, however, require the use of a radiused well bore which presents difficulties in removing the entrained water from the coal seam. The most efficient method for pumping water from a subterranean well, a sucker rod pump, does not work well in horizontal or radiused bores.
[0005] As a result of these difficulties in surface production of methane gas from coal deposits, which must be removed from a coal seam prior to mining, subterranean methods have been employed. While the use of subterranean methods allows water to be easily removed from a coal seam and eliminates under-balanced drilling conditions, they can only access a limited amount of the coal seams exposed by current mining operations. Where longwall mining is practiced, for example, underground drilling rigs are used to drill horizontal holes from a panel currently being mined into an adjacent panel that will later be mined. The limitations of underground rigs limits the reach of such horizontal holes and thus the area that can be effectively drained. In addition, the degasification of a next panel during mining of a current panel limits the time for degasification. As a result, many horizontal bores must be drilled to remove the gas in a limited period of time. Furthermore, in conditions of high gas content or migration of gas through a coal seam, mining may need to be halted or delayed until a next panel can be adequately degasified. These production delays add to the expense associated with degasifying a coal seam.
SUMMARY OF THE INVENTION
[0006] The present invention provides a slant entry well system and method for accessing a subterranean zone from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, certain embodiments of the present invention provide a slant entry well system and method for efficiently producing and removing entrained methane gas and water from a coal seam without requiring excessive use of radiused or articulated well bores or large surface area in which to conduct drilling operations.
[0007] In accordance with one embodiment of the present invention, a guide tube bundle includes two or more guide tubes. Each guide tube includes a first aperture at a first end and a second aperture at a second end. The longitudinal axis of the first aperture of each guide tube is offset from the longitudinal axis of the second aperture of the guide tube Furthermore, the guide tubes are configured longitudinally adjacent to each other and are twisted around one another.
[0008] Embodiments of the present invention may provide one or more technical advantages. These technical advantages may include the formation of a plurality of slanted well bores and drainage patterns to optimize the area of a subsurface formation which may be drained of gas and liquid resources. This allows for more efficient drilling and production and greatly reduces costs and problems associated with other systems and methods.
[0009] Another technical advantage includes providing a method for orienting well bores using a guide tube bundle inserted into an entry well bore. The guide tube bundle allows for the simple orientation of the slant well bores in relation to one another and optimizes the production of resources from subterranean zones by optimizing the spacing between the slanted well bores.
[0010] Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like numerals represent like parts, in which:
[0012] [0012]FIG. 1 illustrates an example slant well system for production of resources from a subterranean zone;
[0013] [0013]FIG. 2A illustrates a vertical well system for production of resources from a subterranean zone;
[0014] [0014]FIG. 2B illustrates a portion of An example slant entry well system in further detail;
[0015] [0015]FIG. 3 illustrates an example method for producing water and gas from a subsurface formation;
[0016] FIGS. 4 A- 4 C illustrate construction of an example guide tube bundle;
[0017] [0017]FIG. 5 illustrates an example entry well bore with an installed guide tube bundle;
[0018] [0018]FIG. 6 illustrates the use of an example guide tube bundle in an entry well bore;
[0019] [0019]FIG. 7 illustrates an example system of slanted well bores;
[0020] [0020]FIG. 8 illustrates an example system of an entry well bore and a slanted well bore;
[0021] [0021]FIG. 9 illustrates an example system of a slanted well bore and an articulated well bore;
[0022] [0022]FIG. 10 illustrates production of water and gas in an example slant well system;
[0023] [0023]FIG. 11 illustrates an example drainage pattern for use with a slant well system; and
[0024] [0024]FIG. 12 illustrates an example alignment of drainage patterns for use with a slant well system.
DETAILED DESCRIPTION OF THE INVENTION
[0025] [0025]FIG. 1 illustrates an example slant well system for accessing a subterranean zone from the surface. In the embodiment described below, the subterranean zone is a coal seam. It will be understood that other subterranean formations and/or low pressure, ultra-low pressure, and low porosity subterranean zones can be similarly accessed using the slant well system of the present invention to remove and/or produce water, hydrocarbons and other fluids in the zone, to treat minerals in the zone prior to mining operations, or to inject or introduce fluids, gases, or other substances into the zone.
[0026] Referring to FIG. 1, a slant well system 10 includes an entry well bore 15 , slant wells 20 , articulated well bores 24 , cavities 26 , and rat holes 27 . Entry well bore 15 extends from the surface 11 towards the subterranean zone 22 . Slant wells 20 extend from the terminus of entry well bore 15 to the subterranean zone 22 , although slant wells 20 may alternatively extend from any other suitable portion of entry well bore 15 . Where there are multiple subterranean zones 22 at varying depths, as in the illustrated example, slant wells 20 extend through the subterranean zones 22 closest to the surface into and through the deepest subterranean zone 22 . Articulated well bores 24 may extend from each slant well 20 into each subterranean zone 22 . Cavity 26 and rat hole 27 are located at the terminus of each slant well 20 .
[0027] In FIGS. 1 , and, 5 - 8 , entry well bore 15 is illustrated as being substantially vertical; however, it should be understood that entry well bore 15 may be formed at any suitable angle relative to the surface 11 to accommodate, for example, surface 11 geometries and attitudes and/or the geometric configuration or attitude of a subterranean resource. In the illustrated embodiment, slant well 20 is formed to angle away from entry well bore 15 at an angle designated alpha, which in the illustrated embodiment is approximately 20 degrees. It will be understood that slant well 20 may be formed at other angles to accommodate surface topologies and other factors similar to those affecting entry well bore 15 . Slant wells 20 are formed in relation to each other at an angular separation of beta degrees, which in the illustrated embodiment is approximately sixty degrees. It will be understood that slant wells 20 may be separated by other angles depending likewise on the topology and geography of the area and location of the target coal seam 22 .
[0028] Slant well 20 may also include a cavity 26 and/or a rat hole 27 located at the terminus of each slant well 20 . Slant wells 20 may include one, both, or neither of cavity 26 and rat hole 27 .
[0029] [0029]FIGS. 2A and 2B illustrate by comparison the advantage of forming slant wells 20 at an angle. Referring to FIG. 2A, a vertical well bore 30 is shown with an articulated well bore 32 extending into a coal seam 22 . As shown by the illustration, fluids drained from coal seam 22 into articulated well bore 32 must travel along articulated well bore 32 upwards towards vertical well bore 30 , a distance of approximately W feet before they may be collected in vertical well bore 30 . This distance of W feet is known as the hydrostatic head and must be overcome before the fluids may be collected from vertical well bore 30 . Referring now to FIG. 2B, a slant entry well 34 is shown with an articulated well bore 36 extending into coal seam 22 . Slant entry well 34 is shown at an angle alpha away from the vertical. As illustrated, fluids collected from coal seam 22 must travel along articulated well bore 36 up to slant entry well 34 , a distance of W′ feet. Thus, the hydrostatic head of a slant entry well system is reduced as compared to a substantially vertical system. Furthermore, by forming slant entry well 34 at angle alpha, the articulated well bore 36 drilled from tangent or kick off point 38 has a greater radius of curvature than articulated well bore 32 associated with vertical well bore 30 . This allows for articulated well bore 36 to be longer than articulated well bore 32 (since the friction of a drill string against the radius portion is reduced), thereby penetrating further into coal seam 22 and draining more of the subterranean zone.
[0030] [0030]FIG. 3 illustrates an example method of forming a slant entry well. The steps of FIG. 3 will be further illustrated in subsequent FIGS. 4 - 11 . The method begins at step 100 where the entry well bore is formed. At step 105 , a fresh water casing or other suitable casing with an attached guide tube bundle is installed into the entry well bore formed at step 100 . At step 110 , the fresh water casing is cemented in place inside the entry well bore of step 100 .
[0031] At step 115 , a drill string is inserted through the entry well bore and one of the guide tubes in the guide tube bundle. At step 120 , the drill string is used to drill approximately fifty feet past the casing. At step 125 , the drill is oriented to the desired angle of the slant well and, at step 130 , a slant well bore is drilled down into and through the target subterranean zone.
[0032] At decisional step 135 , a determination is made whether additional slant wells are required. If additional slant wells are required, the process returns to step 115 and repeats through step 135 . Various means may be employed to guide the drill string into a different guide tube on subsequent runs through steps 115 - 135 , which should be apparent to those skilled in the art.
[0033] If no additional slant wells are required, the process continues to step 140 . At step 140 the slant well casing is installed. Next, at step 145 , a short radius curve is drilled into the target coal seam. Next, at step 150 , a substantially horizontal well bore is drilled into and along the coal seam. It will be understood that the substantially horizontal well bore may depart from a horizontal orientation to account for changes in the orientation of the coal seam. Next, at step 155 , a drainage pattern is drilled into the coal seam through the substantially horizontal well. At decisional step 157 , a determination is made whether additional subterranean zones are to be drained as, for example, when multiple subterranean zones are present at varying depths below the surface. If additional subterranean zones are to be drained, the process repeats steps 145 through 155 for each additional subterranean zone. If no further subterranean zones are to be drained, the process continues to step 160 .
[0034] At step 160 , production equipment is installed into the slant well and at step 165 the process ends with the production of water and gas from the subterranean zone.
[0035] Although the steps have been described in a certain order, it will be understood that they may be performed in any other appropriate order. Furthermore, one or more steps may be omitted, or additional steps performed, as appropriate.
[0036] [0036]FIGS. 4A, 4B, and 4 C illustrate formation of a casing with associated guide tube bundle as described in step 105 of FIG. 3. Referring to FIG. 4A, three guide tubes 40 are shown in side view and end view. The guide tubes 40 are arranged so that they are parallel to one another. In the illustrated embodiment, guide tubes 40 are 9⅝″ joint casings. It will be understood that other suitable materials may be employed.
[0037] [0037]FIG. 4B illustrates a twist incorporated into guide tubes 40 . The guide tubes 40 are twisted gamma degrees in relation to one another while maintaining the lateral arrangement to gamma degrees. Guide tubes 40 are then welded or otherwise stabilized in place. In an example embodiment, gamma is equal to 10 degrees.
[0038] [0038]FIG. 4C illustrates guide tubes 40 , incorporating the twist, in communication and attached to a casing collar 42 . The guide tubes 40 and casing collar 42 together make up the guide tube bundle 43 , which may be attached to a fresh water or other casing sized to fit the length of entry well bore 15 of FIG. 1 or otherwise suitably configured.
[0039] [0039]FIG. 5 illustrates entry well bore 15 with guide tube bundle 43 and casing 44 installed in entry well bore 15 . Entry well bore 15 is formed from the surface 11 to a target depth of approximately three hundred and ninety feet. Entry well bore 15 , as illustrated, has a diameter of approximately twenty-four inches. Forming entry well bore 15 corresponds with step 100 of FIG. 3. Guide tube bundle 43 (consisting of joint casings 40 and casing collar 42 ) is shown attached to a casing 44 . Casing 44 may be any fresh water casing or other casing suitable for use in down-hole operations. Inserting casing 44 and guide tube bundle 43 into entry well bore 15 corresponds with step 105 of FIG. 3.
[0040] Corresponding with step 110 of FIG. 3, a cement retainer 46 is poured or otherwise installed around the casing inside entry well bore 15 . The cement casing may be any mixture or substance otherwise suitable to maintain casing 44 in the desired position with respect to entry well bore 15 .
[0041] [0041]FIG. 6 illustrates entry well bore 15 and casing 44 with guide tube 43 in its operative mode as slant wells 20 are about to be drilled. A drill string 50 is positioned to enter one of the guide tubes 40 of guide tube bundle 43 . In order to keep drill string 50 relatively centered in casing 44 , a stabilizer 52 may be employed. Stabilizer 52 may be a ring and fin type stabilizer or any other stabilizer suitable to keep drill string 50 relatively centered. To keep stabilizer 52 at a desired depth in well bore 15 , stop ring 53 may be employed. Stop ring 53 may be constructed of rubber or metal or any other foreign down-hole environment material suitable. Drill string 50 may be inserted randomly into any of a plurality of guide tubes 40 of guide tube bundle 43 , or drill string 50 may be directed into a selected joint casing 40 . This corresponds to step 115 of FIG. 3.
[0042] [0042]FIG. 7 illustrates an example system of slant wells 20 . Corresponding with step 120 of FIG. 3, tangent well bore 60 is drilled approximately fifty feet past the end of entry well bore 15 (although any other appropriate distance may be drilled). Tangent well bore 60 is drilled away from casing 44 in order to minimize magnetic interference and improve the ability of the drilling crew to guide the drill bit in the desired direction. Corresponding with step 125 of FIG. 3, a radiused well bore 62 is drilled to orient the drill bit in preparation for drilling the slant entry well bore 64 . In a particular embodiment, radiused well bore 62 is curved approximately twelve degrees per one hundred feet (although any other appropriate curvature may be employed).
[0043] Corresponding with step 130 of FIG. 3, a slant entry well bore 64 is drilled from the end of the radius well bore 62 into and through the subterranean zone 22 . Alternatively, slant well 20 may be drilled directly from guide tube 40 , without including tangent well bore 60 or radiused well bore 62 . An articulated well bore 65 is shown in its prospective position but is drilled later in time than rat hole 66 , which is an extension of slant well 64 . Rat hole 66 may also be an enlarged diameter cavity or other suitable structure. After slant entry well bore 64 and rat hole 66 are drilled, any additional desired slant wells are then drilled before proceeding to installing casing in the slant well.
[0044] [0044]FIG. 8 is an illustration of the casing of a slant well 64 . For ease of illustration, only one slant well 64 is shown. Corresponding with step 140 of FIG. 3, a whip stock casing 70 is installed into the slant entry well bore 64 . In the illustrated embodiment, whip stock casing 70 includes a whip stock 72 which is used to mechanically direct a drill string into a desired orientation. It will be understood that other suitable casings may be employed and the use of a whip stock 72 is not necessary when other suitable methods of orienting a drill bit through slant well 64 into the subterranean zone 22 are used.
[0045] Casing 70 is inserted into the entry well bore 15 through guide tube bundle 43 and into slant entry well bore 64 . Whip stock casing 70 is oriented such that whip stock 72 is positioned so that a subsequent drill bit is aligned to drill into the subterranean zone 22 at the desired depth.
[0046] [0046]FIG. 9 illustrates whip stock casing 70 and slant entry well bore 64 . As discussed in conjunction with FIG. 8, whip stock casing 70 is positioned within slant entry well bore 64 such that a drill string 50 will be oriented to pass through slant entry well bore 64 at a desired tangent or kick off point 38 . This corresponds with step 145 of FIG. 3. Drill string 50 is used to drill through slant entry well bore 64 at tangent or kick off point 38 to form articulated well bore 36 . In a particular embodiment, articulated well bore 36 has a radius of approximately seventy-one feet and a curvature of approximately eighty degrees per one hundred feet. In the same embodiment, slant entry well 64 is angled away from the vertical at approximately ten degrees. In this embodiment, the hydrostatic head generated in conjunction with production is roughly thirty feet. However, it should be understood that any other appropriate radius, curvature, and slant angle may be used.
[0047] [0047]FIG. 10 illustrates a slant entry well 64 and articulated well bore 36 after drill string 50 has been used to form articulated well bore 36 . In a particular embodiment, a horizontal well and drainage pattern may then be formed in subterranean zone 22 , as represented by step 150 and step 155 of FIG. 3.
[0048] Referring to FIG. 10, whip stock casing 70 is set on the bottom of rat hole 66 to prepare for production of oil and gas. A sealer ring 74 may be used around the whip stock casing 70 to prevent gas produced from articulated well bore 36 from escaping outside whip stock casing 70 . Gas ports 76 allow escaping gas to enter into and up through whip stock casing 70 for collection at the surface.
[0049] A pump string 78 and submersible pump 80 is used to remove water and other liquids that are collected from the subterranean zone through articulated well bore 36 . As shown in FIG. 10, the liquids, under the power of gravity and the pressure in subterranean zone 22 , pass through articulated well bore 36 and down slant entry well bore 64 into rat hole 66 . From there the liquids travel into the opening in the whip stock 72 of whip stock casing 70 where they come in contact with the installed pump string 78 and submersible pump 80 . Submersible pump 80 may be a variety of submersible pumps suitable for use in a down-hole environment to remove liquids and pump them to the surface through pump string 78 . Installation of pump string 78 and submersible pump 80 corresponds with step 160 of FIG. 3. Production of liquid and gas corresponds with step 165 of FIG. 3.
[0050] [0050]FIG. 11 illustrates an example drainage pattern 90 that may be drilled from articulated well bores 36 . At the center of drainage pattern 90 is entry well bore 15 . Connecting to entry well bore 15 are slant wells 20 . At the terminus of slant well 20 , as described above, are substantially horizontal well bores 92 roughly forming a “crow's foot” pattern off of each of the slant wells 20 . As used throughout this application, “each” means all of a particular subset. In a particular embodiment, the horizontal reach of each substantially horizontal well bore 92 is approximately fifteen hundred feet. Additionally, the lateral spacing between the parallel substantially horizontal well bores 92 is approximately eight hundred feet. In this particular embodiment, a drainage area of approximately two hundred and ninety acres would result. In an alternative embodiment where the horizontal reach of the substantially horizontal well bore 92 is approximately two thousand four hundred and forty feet, the drainage area would expand to approximately six hundred and forty acres. However, any other suitable configurations may be used. Furthermore, any other suitable drainage patterns may be used.
[0051] [0051]FIG. 13 illustrates a plurality of drainage patterns 90 in relationship to one another to maximize the drainage area of a subsurface formation covered by the drainage patterns 90 . Each drainage pattern 90 forms a roughly hexagonal drainage pattern. Accordingly, drainage patterns 90 may be aligned, as illustrated, so that the drainage patterns 90 form a roughly honeycomb-type alignment.
[0052] Although the present invention has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims. | A guide tube bundle includes two or more guide tubes. Each guide tube includes a first aperture at a first end and a second aperture at a second end. The longitudinal axis of the first aperture of each guide tube is offset from the longitudinal axis of the second aperture of the guide tube Furthermore, the guide tubes are configured longitudinally adjacent to each other and are twisted around one another. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Patent application Ser. No. 08/250,724 filed May 27, 1994, now abandoned.
TECHNICAL FIELD
The present invention relates to a hand access hole assembly for reinforcing the hand access hole in a tubular shaft. Numerous applications of tubular shafts, for example, utility poles such as those supporting street lights and traffic signals, require access into the interior of the shaft for installation and maintenance purposes. It is well known that creation of an access hole causes a loss of strength at and near the point where the hole is created. Reasons for loss of strength include elimination of material at the site of the hole and application of heat that can cause metallurgical changes. It is therefore desirable to reinforce the shaft at the point where an access hole has been created. The present invention provides a hand access hole assembly that restores the strength of the shaft to at least its level before the hole was made and is, moreover, inexpensive to fabricate and convenient to use.
BACKGROUND OF THE INVENTION
There are, of course, numerous devices and techniques known in the art for dealing with the consequences of providing access holes in tubular shafts. Recent natural disasters, including Hurricane Andrew, have brought about an increased public awareness of potential hazards and the damage that can occur due to failure of utility poles.
Various aspects of hand holes in tubular shafts are disclosed (or shown) in U.S. Pat. Nos. 3,364,952, 3,550,637, 3,624,269, and 4,914,258. Of the foregoing, only U.S. Pat. No. 3,550,637 deals with a device and method for strengthening the shaft after a hole has been made therein. In the latter patent a plate having a hole corresponding to the hole in the tubular shaft is welded to the inside surface of the shaft, and a cover is placed over the opening. The present invention differs from that patent, and all other prior art of which I am aware, in many significant respects which will be made apparent in the disclosure that follows.
SUMMARY OF THE INVENTION
The present invention is directed to a hand access hole assembly for use in a tubular shaft having an access hole, wherein the assembly strengthens the tubular shaft in the area of the access hole.
According to a preferred embodiment of the present invention the hand access hole assembly comprises first and second reinforcing units which are secured to one another. The first reinforcing unit has a central opening extending therethrough and a flange portion surrounding the opening for placement inside the shaft at the site of the shaft access hole. The flange portion has a first surface contacting the inner surface of the shaft and having a contour generally the same as the inner contour of the shaft. The first reinforcing unit further includes a plurality of tenons protruding outwardly from the surface, the tenons alternating with open spaces and the outer edges of the tenons defining a shape substantially corresponding to the shape of the access hole in the shaft. The second reinforcing unit also has a central opening extending therethrough and a flange portion surrounding the opening for placement on the outside of the shaft at the site of the shaft access hole. The flange portion has a first surface contacting the outer surface of the shaft and having a contour generally the same as the outer contour of the shaft. The second unit further includes a plurality of tenons protruding inwardly from the surface, the tenons alternating with open spaces and the outer edges of said tenons defining a shape substantially corresponding to the shape of the access hole in the shaft. The tenons and open spaces are positioned such that the tenons of the first unit mate with the spaces of the second unit and the tenons of the second unit mate with the spaces of the first unit forming a periphery that is substantially devoid of open spaces between the tenons.
In another preferred embodiment of the present invention, the hand access hole assembly comprises an outer and an inner reinforcing unit which are secured to one another in a manner which is slightly different from that described above. In this configuration, the outer reinforcing unit has a central opening extending therethrough and a flange portion surrounding the opening for placement inside the shaft at the site of the shaft access hole in a manner as described previously. In one aspect of this embodiment, the outer unit is split into two components for ease of insertion into the access hole of the shaft. However, rather than having a plurality of tenons which protrude outwardly from the surface, the outer unit has a plurality of tenons which protrude inwardly from an interior surface of the outer unit, the tenons configured to be in mating engagement with an equal number of mortises on the inner unit, this second inner unit also having a central opening extending therethrough.
BRIEF DESCRIPTION OF THE DRAWINGS
The structural features and functions of the present invention, as well as the advantages of the present invention, will become apparent from the subsequent detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a view which illustrates a tubular pole having a hand access hole which incorporates the hand access hole assembly according to the present invention;
FIG. 2 is a plan view of a first preferred embodiment of the invention;
FIG. 3 is a perspective view of the first side of one of the reinforcing units of the first preferred embodiment of the invention;
FIG. 4 is a perspective view of the reverse side of the reinforcing unit illustrated in FIG. 3;
FIG. 5 is an exploded vertical sectional view of a hand access hole assembly and a pole according to a second preferred embodiment of the present invention.
FIG. 6 is a plan view of a second preferred embodiment of the invention;
FIG. 7 is a perspective view of the first side of one of the reinforcing units of the second preferred embodiment;
FIG. 8 is a perspective view of the reverse side of the reinforcing unit illustrated in FIG. 7; and
FIG. 9 is a perspective view of the first side of one of the reinforcing units of the third preferred embodiment;
FIG. 10 is a plan view of the third preferred embodiment of an outer part of the reinforcing unit showing inwardly facing tenons;
FIG. 11 is a perspective view of the preferred embodiment of an inner part of the reinforcing unit showing outwardly facing mortises to mate with the tenons of the outer reinforcing unit of FIG. 10;
FIG. 12 is a plan view of another embodiment of the invention showing the outer part of the reinforcing unit with mortises;
FIG. 13 is a perspective view showing the inner part of the reinforcing unit showing outwardly facing tenons which mate with the mortises shown in FIG. 12;
FIG. 14 is a plan view of another embodiment of the invention showing the outer part of the reinforcing unit with at least one tenon and at least one mortise; and
FIG. 15 is a perspective view showing the inner part of the reinforcing unit showing at least one tenon and at least one mortise each of which will correspondingly mate with the appropriate mortise or tenon shown in FIG. 14.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to a reinforcement assembly for the hand access hole to a tubular shaft, and will be described in full below with reference to the drawings. The hand hole provides access to the interior of the tubular shaft for installation and maintenance, and the reinforcement assembly of this invention restores strength to the shaft that was lost by providing the hole therein.
FIG. 1 illustrates a tubular shaft, comprising a pole 1 which incorporates the hand access hole assembly 10 constructed according to the present invention. Pole 1 is mounted on the ground 2, and supporting a street light 3. A hand access hole 4 is provided in the pole at a point near the ground for easy access by workers.
The hand access hole assembly 10 comprises two reinforcing units that are joined to each other and to the tubular shaft 1 by fastening means typically comprising bolts and nuts. FIGS. 2-4 illustrate one embodiment of the invention wherein FIG. 2 is a plan view of the first side, FIG. 3 is a perspective view of the first side, and FIG. 4 is a perspective view of the reverse side of one of the reinforcing units, generally indicated by 11. Each unit 11 has holes 12 through which fastening means are inserted for attachment. Unit 11 has four tenons 13, 14, 15, and 16, and four spaces 17, 18, 19, and 20 for receiving the tenons. Each reinforcing unit 11 has a central opening 60 extending therethrough and a flange portion 62 surrounding opening 60. As shown in FIGS. 3 and 4, tenons 13, 14, 15, and 16 are flush with a surface 64 of flange portion 62, on a first side of unit 11, and protrude beyond a surface 66 of flange portion 62 on the reverse side of unit 11.
When installed in a hand access hole the assembly 10 comprises two identical units 11 (except when installed in a round shaft). The two units 11 are assembled with the tenons of one unit sliding into the spaces of the other. That is, tenons 13, 14, 15, and 16 of one unit slide into spaces 17, 18, 19, and 20, respectively, of the second unit. The outer edges 68, 70, 72, and 74 of tenons 13, 14, 15, and 16, respectively, define a shape substantially corresponding to the shape of access hole 4 in shaft 1. In the embodiment illustrated in FIGS. 2-4, surfaces 64 and 66 of flange portion 62 are preferably substantially flat and therefore have a contour which is generally the same as the mating planar surfaces of shaft 1. As shown in FIGS. 3 and 4, tenons 13, 14, 15, and 16 protrude inwardly from surface 64 of flange portion 62 and protrude outwardly, at substantially 90°, from surface 66 of flange portion 62. One unit of the assembly is placed inside the shaft and the other on the outside with the edges around the cut-out in the pole clamped between the two units. Bolts inserted through holes 12 and nuts apply pressure and act as a clamp on the edges around the cut-out, thus reinforcing the shaft 1. The tenons and spaces fit together in a snug but not tight manner. The two units 11 can be easily joined and separated so long as force is applied uniformly, and they are kept substantially parallel to each other. However, if force is applied at approximately 90° at any point around the periphery the tenons will hold the two units rigidly together. This characteristic increases the clamping action around the entire periphery of the cut-out when stress is applied to the shaft (for example, by wind or other external forces) and supplements the holding power of the bolts.
When the two units of the assembly are joined as described, they provide a smooth, uniform hand access hole through the assembly into the interior of the tubular shaft.
Although it does not constitute a part of the present invention, a cover will be provided over the assembly to prevent tampering and the entry of foreign materials.
FIGS. 5-8 illustrate a second embodiment of the hand access hole assembly of the present invention, indicated generally at 80. As shown in FIG. 5, which is an exploded sectional view of assembly 80, assembly 80 includes two reinforcing units 21 which are identical to one another and are designated as 21a and 21b for purposes of illustration in FIG. 5. FIG. 5 further illustrates the relationship of units 21a and 21b with a wall 51 of a tubular shaft or pole. Hole 52, which provides hand access, and holes 53, for insertion of fastening means, are provided in wall 51 of the shaft by any suitable means. Unit 21a is inserted through hole 52 into the interior of the tubular shaft and held in place while unit 21b is joined with it on the outside of the shaft, and units 21a and 21b are then attached by bolts 54 and nuts 55. FIG. 6 illustrates a plan view of unit a 21 and FIGS. 7 and 8 illustrate perspective views of opposing sides of the unit 21. The two identical units 21 can be fit together, or assembled, to form the assembly 80 by joining the tenons 22, 23, 24, 25, 26, and 27 of a first unit 21 with spaces 28, 29, 30, 31, 32, and 33, respectively, of a second unit 21 in the same manner as described with reference to units 11 illustrated in FIGS. 3 and 4. This embodiment differs from that shown in FIGS. 2-4 by having additional tenons surrounding the hand access hole, and, more significantly, by mount hole tenons surrounding holes 33a. Accordingly, completion of the assembly includes mating tenons 34, 35, 36, 40, 41, and 42 of a first unit with spaces 37, 38, 39, 43, 44, and 45 of a second unit, respectively.
Each unit 21 includes a central opening 76 extending through the unit 21, and a flange portion 78 surrounding the central opening 76. Tenons 22, 23, 24, 25, 26, and 27 protrude inwardly from surface 80 of flange portion 78, as shown in FIG. 7, and protrude outwardly from surface 82 of flange portion 78 as shown in FIG. 8. The tenons 22, 23, 24, 25, 26, and 27 protrude at substantially 90° from surfaces 80 and 82. Additionally, in a manner similar to that of the embodiment of the present invention illustrated in FIGS. 1-4, tenons 22, 23, 24, 25, 26, and 27 include outer edges 84, 86, 88, 90, 92, and 94, respectively, which define a shape substantially corresponding to the shape of access hole 52.
In another embodiment of this invention, shown in FIGS. 9-11, the hand access hole assembly is indicated generally at 100. As shown in FIG. 9, which is a perspective view of the assembly 100, the assembly includes an outer reinforcing unit 140 (shown by itself in FIG. 10) and an inner reinforcing unit 120 (shown by itself in FIG. 11). Hole 114 provides hand access into the tubular shaft, whereas holes 112 are for insertion of fastening means (not shown). As in the previously described embodiments, an outer lip portion 106 which substantially conforms to the opening with the tubular shaft, will serve to define groove 110 which facilitates anchoring within the shaft. In a more preferred embodiment, the outer reinforcing unit 140 is split into two components, a first half 102 and a second mating half 104 to facilitate the insertion of the outer reinforcing unit 140 into the shaft. The outer reinforcing unit 140 has a plurality of tenons 116,118 which protrude inwardly from the inner surface of the unit while the inner reinforcing unit 120 has a corresponding number of mating mortises 126,128 for engagement therewith the tenons.
As seen in FIG. 10, a plurality of tenons 116,118 are positioned about an inner periphery of the outer reinforcing unit 140 with open spaces 122,124 between the inwardly protruding tenons. The shape of the tenon is not critical, but may be tailored to meet the stress demands of the application. The tenon can be dove shaped as seen by tenon 116 or trapezoidal shaped as seen by tenons 118. Other geometric shapes are also envisioned within the scope of this invention, e.g., rectangular or square shaped. In a more preferred embodiment, the outer reinforcing unit 140 is split along 138 into two components, a first half 102 and a second half 104, the two halves being capable of independent insertion into an opening within a shaft and held together by a mating mortise 136 and tenon 134, although other equivalent mating means are additional envisioned to be applicable and yet remain within the bounds of this invention. As illustrated in FIG. 11, an inner reinforcing unit 120 is configured so as to matingly engage with the outer reinforcing unit 140. This unit will have a corresponding number of mortises 126,128 to the number of tenons present about the inner periphery of the outer reinforcing unit 140. While the mating mortise and tenons are shown to be six (6) in number in the figures, more or less are envisioned. It is envisioned that at few as two (2) would be effective in achieving the purposes of this invention. The upper limit is not a fixed number, but rather is a function of the size of the opening in the shaft. It is recognized that the units will fit together in a snug, but not tight manner with the tenons 116,118,134 mating with mortises 128,126,136 respectively and the open spaces 122,124 being adjacent to regions 132,130 respectively.
While the invention in this third embodiment has been described as having at least one tenon in the outer reinforcing member 140 and at least one mating mortise in the inner reinforcing member 120, there is no reason why the locations of the mortises and tenons could not be interposed as seen in FIGS. 12-13. In these figures, the tenons 162,164 are shown as being positioned within inner reinforcing member 160 while the mating mortises 154,152 are shown in the outer reinforcing member 150. As seen in these figures, open spaces 166,168 will be adjacent to regions 156,158 respectively in a manner described previously. All other reference numerals which describe aspects of the invention which have been previously described, are maintained for purposes of continuity.
In yet another variation of this embodiment of the invention, shown in FIGS. 14-15, the outer reinforcing member 170 is shown to contain at least one tenon 116,118 and at least one mortise 152,154 into which will be matingly inserted an inner reinforcing member 180 which also has at least one tenon 162,164 and at least one mortise 126,128. As seen in these figures, tenons 162,164 will matingly engage mortises 154,152 respectively while tenons 116,118 will matingly engage mortises 128,126 respectively.
While the invention is described and illustrated in the drawings as being installed in tubular shafts having at least one planar surface, it is also contemplated that it be installed in shafts having a substantially round cross section. The two units for use in an assembly installed in a round shaft would be curved at the radius to correspond to the shaft, and therefore could not be identical as in the case of those installed on a planar surface. However, the same principles would apply to the mating and joining of the tenons and spaces as have been described with respect to the assemblies used on a planar surface.
The units used in the hand access hole assemblies described herein can be fabricated from any suitable material. The preferred material, as now contemplated, is aluminum. Also, the units can be made using conventional molding techniques. The assemblies are suitable for numerous applications including poles supporting street lights, traffic signals, stadium lights, other electrical fixtures and other shafts in applications requiring hand access to the interior of the shaft.
The hand access hole assembly of the present invention may be advantageously used for strengthening a tubular shaft at and around the hand access hole in the shaft which is typically provided close to the ground for easy access by maintenance personnel. The hand access hole assembly of the present invention is inexpensive, easy to fabricate and convenient to use, and may be used with either new or existing tubular shafts, having either planar or curved surfaces mating with the reinforcing units of the hand access hole assembly. Further, it is noted that the hand access hole assembly of the present invention may be installed, at the point of use in the field, with simple hand tools. The addition of the hand access hole assembly of the present invention to a tubular shaft allows the shaft to carry increased loads such as those produced by wind acting on the tubular shaft.
While the foregoing description has set forth the preferred embodiments of the invention in particular detail, it must be understood that numerous modifications, substitutions and changes can be taken without departing from the true spirit and scope of the present invention as defined by the ensuing claims. The invention is therefore not limited to specific preferred embodiments as described, but is only limited by the following claims. | A reinforcement assembly for use in the hand access hole of a tubular shaft. In one embodiment, the assembly includes a pair of units placed opposing each other with one being inside the shaft and the other being outside the shaft. Each unit has a plurality of tenons that mate with open spaces of the opposing unit, and each has a flange surrounding the tenons that contact the shaft in the area immediately surrounding the hand hole. The two units are attached to each other and to the shaft by bolts or other suitable fastening devices. In another embodiment of this invention, the pair of units are positioned one inside the other with at least one mating mortise and tenon union for securely linking the units. A typical application of the assembly is reinforcement of the area surrounding the hand hole of a utility pole. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional application Ser. No. 60/899,912 filed on Feb. 6, 2007, U.S. provisional application Ser. No. 60/900,851 filed on Feb. 11, 2007, U.S. provisional application Ser. No. 60/921,584 filed on Apr. 1, 2007, and U.S. provisional application Ser. No. 60/961,963 filed on Jul. 24, 2007, each of which is incorporated herein by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0003] Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
[0004] A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. § 1.14.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] This invention pertains generally to water dispensers, and more particularly to water purification and cooling systems for pets.
[0007] 2. Description of Related Art
[0008] Animal or pet care has become an increasingly large industry. However, little has been done to remove pathogens and other contaminants from pet drinking water. Contaminants and/or pathogens may be inherent in the water supply, added to the water from airborne particles landing in the water, or introduced from one of the pets itself, e.g., from their oral cavity or contaminated or disease carrying hair from the pet falling into the water supply.
[0009] Most all sources of public or private water have an allowable amount of organisms that may become or already are pathogenic to humans or animals. Further, the air in an enclosed area such as a house often contains potential pathogens such as molds, mildew, bacteria and viruses and these airborne organisms tend to land on any horizon or vertical surface such as the water surface. Animals may also carry dry food from another bowl and deposit the dry food into the water supply, which can add pathogens to the water supply and also furnish a supply of nutrients for growing colonies of pathogens.
[0010] Viruses have been shown to remain active and potentially virulent for many hours or days after the virus was deposited on a surface and are capable of spreading into a body via the nose, eyes, mouth, lungs or a break in the skin. Once an organism enters the body, infection may occur, as well as damage to internal organs, particularly the kidneys, lungs and eyes. Viruses may also be a precursor to many lethal cancers. In cats, chronic or repeated exposure to certain pathogens has been linked to feline kidney failure. It has been shown that many breeds of cats have a genetic predisposition to kidney disease and accordingly, any reduction in biologic or inorganic materials is highly desirable.
[0011] The most common solution to provide a supply of drinking water to a pet generally comprises a simple bowl, pan, bucket or like device that can hold water, wherein the caretaker of the pet adds water to the container as needed. Other devices connect in fluid communication to a pressurized water supply, such as a spigot or garden hose, where the water is constantly running causing the container to frequently overflow. Some devices maintain a predetermined water level and open the water supply unit until the desired level is attained. Some devices allow a pet to perform an action that momentarily opens the pressurized water source so the pet can lick the water upon release of an actuator. Recently, various pet watering devices have been introduced that have an internal and submerged pump that lifts the water above the standing water level and allows the elevated water to flow back into the container so a fountain appearance is attained to give the illusion of a fresh and flowing water supply.
[0012] The above-described conventional animal watering devices have a number of drawbacks. First, none of the above-described devices effectively controls or minimizes the presence of contaminants/pathogens in the drinking water. Many of these devices provide stagnant or standing water, which is a perfect environment to promote the growth of any organism introduced into the water via the skin (including any hair or fur), respiratory tract, urinary system (e.g. spraying), ambient room air or from the oral cavity. As a result, these feeding devices often have problems with algae formation, mold, mildew, etc.
[0013] Another problem with existing products is the difficulty in maintaining cleanliness and/or cleaning surfaces used for retaining water. Inlets and outlets to these water-retaining receptacles often have surfaces that are difficult to reach for cleaning. In addition, the construction and/or materials (e.g. plastics) are not conducive for being washed or cleaned in water hot enough to kill pathogens without deforming or destroying the container, and/or are not dishwasher compatible.
[0014] The materials used for constructing existing device designs may also retain heat and therefore keep the water at a higher than desirable temperature. These higher temperatures reduce the desirability of an animal to drink. Animals generally should drink large amounts of water to keep their organ systems healthy. For example, water intake is helpful to allow the liver and kidney's to adequately flush and excrete undesirable metabolites, pathogens and other undesirable chemicals and compounds.
[0015] Furthermore, such materials may attract and retain substances that make the water undesirable to the animals and therefore reduce the amount of water that the animal might otherwise drink, or become etched and support bacterial or other growth. Because the water retaining portions of existing systems are contiguous with the body of the device, they tend to be constructed of lightweight materials that subject the device to spilling or being tipped over. In addition, water-retaining receptacles that are manufactured out of plastic may result are known to expel contaminants from both the plastic and colorants contained therein.
[0016] Where existing systems have filters, such filters are often hidden from plain site, thus making it difficult to determine or visualize when that filter is clogged and in need of exchange.
[0017] In existing systems employing pumps for circulation of water, such pumps are in free communication with the retained water, leaving the pumps susceptible to debris buildup and failure.
[0018] Therefore, an object of the present invention is to provide a source of drinking water is substantially free of toxins and pathogens and the resultant metabolic wastes that causes bothersome, expensive, and life threatening diseases.
[0019] Another object of the present invention is to provide a cool source of drinking water to encourage adequate hydration of the animal and inhibit growth of pathogens.
[0020] Another object of the present invention is to provide a source of drinking water that is dispensed in a fashion that attracts pets to drink from the source of water.
[0021] At least some of these objectives will be met in the description detailed below.
BRIEF SUMMARY OF THE INVENTION
[0022] The present invention relates generally to animal watering stations and more specifically to an aseptic watering station for pets that provides a source of drinking water substantially free of toxins, pathogens, resultant metabolic wastes, or other contaminants that may cause bothersome, expensive, and life threatening diseases. The present invention is also configured to keep the water at a cooler temperature to encourage adequate hydration of the animal.
[0023] An aspect of the invention is a pet watering station having a basin configured to hold a volume of drinking water, a pump in fluid communication with the basin via an intake, and a sterilization unit in fluid communication with the pump. The sterilization unit is configured to kill organisms in the water. The watering station also includes one or more filters coupled to the sterilization unit and pump to screen particles from the water, and an outlet disposed above the basin for directing the filtered and sterilized water into the basin. Silver ions, silver compounds or similar anti-bacterial agents may also be added to the charcoal in the filter to kill pathogens that are in the water. The antimicrobial substances may be included in the filtering substrate, such as silver inside the carbon matrix.
[0024] In one embodiment, the basin comprises a bowl-shaped receptacle having elevated sidewalls that cool the basin via surface-water evaporation. Preferably, the watering system also includes a base configured to house the basin, pump and sterilization unit. The basin is configured to be detachably removed from the base so that it may be readily cleaned or placed in a dishwasher for cleaning. In another embodiment, the sidewalls of the basin terminate at a lip formed around the circumference of the basin, so that the lip can rest above an opening in the base and be suspended within the base. The basin may also comprise an uninterrupted inner surface that facilitates cleaning and manufacturing.
[0025] In one embodiment, a series and/or system of materials may be inserted between the exterior bottom of the basin and extending to the floor, to provide additional cooling when the temperature of the floor is less than the ambient room temperature, e.g., to function as a heat-sink when the temperature of the floor is less than the ambient air temperature.
[0026] The watering system may also include an intake filter at or near the intake to screen the water from particulates prior to the water entering the pump. The intake filter not only serves to protect the pump from failure, but functions to keep the plastic or glass interface of the downstream UV sterilization unit clean to maintain the “kill rate” of the UV unit and also prevent particulate matter from shielding a pathogen from the UV light.
[0027] In a preferred embodiment, an elevated container is supported above the basin. The elevated container configured to retain a volume of water, wherein the outlet is directed into the elevated container to at least partially fill the elevated container with water. The container has a spout or nozzle located near the bottom surface of the elevated container and is configured to direct water into the basin according to the idiosyncrasies of the pet and/or pet owner.
[0028] In one embodiment, the elevated container comprises a porous material that absorbs water from an inside surface of the container to cool the container, thereby cooling the water.
[0029] In a preferred embodiment, the elevated container is configured to house the filter at a location toward the bottom surface of the container so that water entering from the outlet passes through the filter before exiting out the spout. The spout is adjustable to vary the direction and rate of water entering the basin. The container may also be configured to house or be coupled directly to a sterilization means, such as a UV sterilization unit.
[0030] In another preferred embodiment, the sterilizer comprises a UV lamp configured to direct UV light at water distributed from said pump. Other sterilization means, such as ozone, antimicrobial solutions, etc. may also be employed. In one embodiment, the basin comprises an inner surface coated with an antimicrobial solution that is configured to sterilize said water.
[0031] Another aspect is a method for providing drinking water to an animal or pet. The method includes the steps of dispensing a volume of water in a basin configured to retain the water, displacing at least a portion of the volume of water out of the pump via an intake line, sterilizing the water and redirecting the water into the basin.
[0032] Preferably, the method also includes filtering particulates from the water. Filtering may be performed at the intake and/or after said sterilization of the water.
[0033] In one embodiment, generating a negative pressure at the intake via a pump in communication with the intake displaces the water.
[0034] In another embodiment, the method further includes elevating the water to a container above the basin, filtering the water as it passes through the container, and directing the water into the basin via a spout in the container. The spout is preferably adjustable so that it can be manipulated to change the direction or flow of water into the basin, e.g. a jet or stream of water into the basin, or a drip or water into the basin, or to cause currents in the water so as to minimize “dead spots” in the bowl that may harbor deleterious organisms or particulate matter.
[0035] The method also includes the steps of cooling the volume of water retained in said basin. In a preferred embodiment, the water is cooled from evaporative cooling of the basin and/or elevated container.
[0036] Another aspect is a system for providing drinking water to animals having a basin configured to hold a volume of drinking water, a water treatment module configured to treat the volume of water for consumption and circulate said water in and out of said basin, and a base configured to house the water treatment module and basin, wherein said basin is detachably received on said base.
[0037] The water treatment module or unit preferably has a sterilization unit configured to kill organisms present in the volume of water, e.g., a UV lamp configured to direct UV light at water distributed from said pump. The water treatment module may also have a pump coupled to the sterilization unit to draw water in from an intake at the basin and circulate the water between the basin and the sterilization unit. The water treatment module may also include a filtration unit coupled to the pump and the sterilization unit to filter particulates from the volume of water. The filtration unit may include an intake filter at or near the intake that screens particulates from the water prior to entering the pump, and/or a filter following the sterilization unit, pump, or other location.
[0038] In one embodiment of the current aspect, an elevated container is supported above the basin. The elevated container configured to support a volume of water supplied from the water treatment module to at least partially fill the elevated container with water. A spout is located near the bottom surface of the elevated container to direct water into the basin.
[0039] Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0040] The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
[0041] FIG. 1 is a perspective view of a pet watering system in accordance with the present invention.
[0042] FIG. 2 is front perspective view of the watering system of FIG. 1 with the watering basin removed.
[0043] FIG. 3 is a section view of the watering system of FIG. 1 .
[0044] FIG. 4 is a side view of an alternative basin and filter configuration of the watering system of the present invention.
[0045] FIG. 5 is a side view of another alternative basin and filter configuration of the watering system of the present invention.
[0046] FIG. 6 is a side view of an alternative watering system of the present invention.
[0047] FIG. 7 is a side view of an alternative elevated container for the watering system of the present invention.
[0048] FIG. 8 is a side view of an alternative watering system of the present invention.
[0049] FIG. 9 is a top view of the watering system of FIG. 8 .
[0050] FIG. 10 is an alternative configuration of the watering system of FIG. 8 .
[0051] FIG. 11 illustrates a schematic diagram of a filter overflow setup in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0052] Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 11 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein.
[0053] FIGS. 1-3 illustrate a pet watering system 10 in accordance with the present invention. Watering system 10 comprises a base or cabinet 12 that is configured to support a basin 14 . The cabinet may be constructed of wood, plastic, or other polymer strong enough to support the weight of the basin 14 and water. As shown in FIG. 1 , the basin 14 is generally a bowl-shaped receptacle configured to retain a volume of water for consumption by an animal or pet. The basin 14 comprises a symmetric shape and large opening that facilitates cleaning and evaporative cooling.
[0054] Referring to FIG. 2 , the basin 14 is shaped to have fairly deep walls that terminate in a lip 40 that rests over a cutout 38 of the top surface 26 of cabinet 12 . In this configuration, the basin 14 may be readily removed from the cabinet 12 to allow access to the cavity 44 and the contents therein, or to allow the basin 14 to be separately cleaned. The cabinet 12 has an upper panel 26 that may be removed to add further access into the cavity 44 . The side panels of the cabinet 26 have cutouts 22 that serve as handles for moving the system 10 , and allow ventilation to keep the cavity 44 cool.
[0055] In a preferred embodiment, the cabinet walls are fairly high to allow the basin 14 to be suspended within cavity 44 . The generally deep sidewalls of the basin 14 not only provide for a larger volume of water, but also allow cooling of the water via evaporation.
[0056] Watering system 10 is preferably configured with sterilization and purification means to keep the water in basin 14 substantially free of contaminants, particulates and/or pathogens. Water is first extracted from basin 14 via intake tube 24 that draws the water to the other elements of the system (e.g. from negative pressure caused by a pump or differences in elevation relative to the water level of the bowl).
[0057] The distal end of intake tube 24 is preferably configured to have an intake filter 28 . Intake filter 28 may be any number of replaceable filters configured to screen particulates (e.g. hair, dust, debris) from the basin water that would be deleterious to the operation of downstream elements. In one configuration, the intake filter 28 comprises high-density cylindrical foam that is attached to intake tube 24 via a coupling 25 .
[0058] In one configuration, the intake filter 28 comprises a material and/or color that provides visual indication of the condition of the filter. For example, the filter 28 may comprise a white or light colored foam that darkens as particulates are screened from the water. When the filter 28 has turned dark grey or black, it serves as an indicator to the user that the filter 28 may need replacement.
[0059] As shown in FIG. 3 , the intake tube 24 is configured to pass up and over the basin 14 and into the cabinet 12 , or alternatively into a pump that is located in the structure 27 . This configuration allows the basin to be uninterrupted, which is preferred for ease of removing the basin 14 , and for cleaning the basin. The absence of a through hole in the basin 14 prevents the occurrence of surfaces that are difficult to reach and therefore inhibit bacterial growth or the like.
[0060] In an alternative embodiment shown in FIG. 4 , basin 14 may be configured with a through hole 70 so that intake tube 24 may pass through the bottom of the basin 14 . This configuration may be used where aesthetics are desired. A coupling 72 may be provided (e.g. a quick release, or threaded attachment) to allow the basin 14 to be separated from the remainder of the system.
[0061] In another alternative embodiment shown in FIG. 5 , the intake filter 28 may be positioned under the basin 14 in the cavity 44 of cabinet 12 . This configuration may be desirable for additional aesthetics, and for pets that tend to disturb the filter while visible in the basin 14 . Seal 74 may be provided around through-hole 70 to ensure water does not leak into the cabinet 12 . The placement of filter 28 inside cabinet may also be implemented similarly in the non-interrupted basin configuration shown in FIG. 4 .
[0062] Referring back to FIGS. 2 and 3 , intake line 24 is coupled to a pump 50 . Pump 50 is configured to be strong enough to draw water through the various elements and filters in the system, while being relatively quiet in operation so as to minimize annoyance to either pets or those in close vicinity to the system. The pump 50 may also be insulated to further dampen noise produced by its operation.
[0063] The pump 50 pushes water through connecting line 52 to a sterilization unit 56 . The sterilization unit 56 , described in further detail below, is configured to substantially eradicate living organisms that may be present in the water.
[0064] During transportation of the system 10 or replacement of filters or the basin, lines 24 and 60 may be provided with a shut-off valve or clamp to retain the water within the pump 50 and sterilization unit 56 . This allows the pump and sterilization unit to always maintain a level of water so that they are not subject to a dry start when started up.
[0065] As illustrated in FIG. 3 , a GFI protected electrical cord 64 delivers power to the various components such as the pump 50 , sterilizer 56 , lighting, optional cooling unit 80 or any other device that requires electricity. The cord 64 preferably has a switch 66 that allows the user to power the system 10 on and off.
[0066] The water than passes along outlet line 60 and up the cabinet 12 (under pressure provided by pump 50 ) to elevated container 16 . The elevated container 16 is configured to generate a stream of filtered and purified water back into the basin 14 . Container 16 is elevated above the basin 14 and retained by vertical support 27 that extends above the top surface 26 of the cabinet. A flexible band 32 with tightening means 34 may be used to stabilize and hold the elevated container 16 to the vertical support 27 , and is generally adjustable to lock in the canister when desired.
[0067] Container 16 has an opening 36 at its top and is configured to retain one or more filter elements 62 (e.g. charcoal or similar filtering means) and/or a filter containing an antimicrobial substance, and accepts water from outlet line 60 at the top of the container. Outlet line 60 may enter the container 16 through opening 68 , or may pass over the top of the container and pour into opening 36 . Although FIG. 3 shows output line 60 passing out of the rear panel of cabinet 12 and over support 27 to container 16 , it is appreciated that line 60 may be routed a number of different ways. For example, line 60 may be routed through support 27 or upper panel 26 and into container 16 .
[0068] The water exiting out of line 60 then drains into elevated container 16 to at least partially fill the container. As water fills the container 16 , gravity tends to push the water through the cylindrical (or other shape to generally match the shape of the container) filter 62 toward the bottom of the container.
[0069] Elevated slightly higher than the bottom surface of the container 16 is a port 18 having a nozzle or spout 20 protruding there through to direct water into the basin 14 . Nozzle 20 preferably comprises is a straight or curved elastic tube of plastic or other inert material that is configured to be pliable to bend to different angles to change the direction and/or flow characteristics of the water entering the basin. Nozzle 20 may also direct the stream of water to enhance, diminish or retard the noise and splashing from the water entering the bowl. The nozzle 20 may also have an additional filter 78 to collect dust and other particulate matter from the charcoal filter 62 and other sources.
[0070] If and when the filter 62 becomes clogged with debris, water will tend to drain out nozzle 20 at a slower rate than is input from output line 60 . This will generally cause the water level to rise. Overflow port 30 is located at the upper and frontal end of the container 16 and allows the water to drain into the basin in such case either filter 62 , 78 or nozzle 20 is clogged. Such occurrence will also serve to indicate to the user that a filter is occluded and in need of replacement.
[0071] FIG. 6 illustrates an alternative pet watering system 100 having a filter 112 directly following sterilization unit 110 within cabinet 102 . In system 100 , water from bowl 104 enters line 24 through intake filter 106 that is located at the bottom of the bowl. Pressure from pump 108 draws the water into the sterilization unit and through the filter 112 , and is then driven up tube 60 to outlet 116 where it streams back into the bowl 104 . Because the filter 112 is located within the cabinet 102 , no elevated container, as shown FIGS. 1-3 , is required. However, an elevated container may still be implemented via support 118 to provide additional cooling and/or water manipulation characteristics. FIG. 6 illustrates line 24 running through the bowl 104 prior to reaching pump 108 . However, it is appreciated that bowl 104 may be uninterrupted as well, with line 24 running up and over bowl and into cabinet 102 to meet up with the pumps intake. In addition, filter 106 may be positioned within cabinet 102 .
[0072] FIG. 7 illustrates another alternative embodiment of a watering system 100 showing an elevated container 132 with cap 136 . In this configuration, cap 136 is positioned on the upper end of container 132 to form a seal at 142 . Water enters the container 132 via output tube 140 , which passes through opening 138 in cap 136 . As water enters the container 132 , it travels downward through filter bag 144 to exit out spout 134 . A secondary filter 146 may be positioned at the entrance of spout 134 to filter any debris (e.g. charcoal) from the filter 144 . Spout 134 is preferably bendable to alter the angle of water entry into the basin.
[0073] The entry hole 138 in cap 136 may also be oversized such that water seeps through the hole and either drips or streams down the outside of container 132 to add additional water dispensing into the basin.
[0074] The cap 136 is configured to fit snugly into container 132 so as to resist a small amount of water pressure from water level 148 rising. However, if the water level 148 rises at a rapid rate so as to increase pressure, the cap 135 is configured to pop out of the container, indicating to the user that one of the filters 144 , 146 needs replacement.
[0075] The container 132 may also be composed of a clear substance, e.g., glass, that promotes visibility of the filter 144 , so that the user has indication of the filter's condition.
[0076] The all of the embodiments disclosed heretofore and below are configured to provide sterilization of the drinking water via one of, or a combination of, several different modalities. In a preferred embodiment, the sterilization unit ( 56 , 110 ) comprises a UV a lamp that emits ultra violet radiation in a spectrum that is germicidal. Preferably the lamp is not in direct contact with the water, e.g. the lamp is positioned inside of a highly clear tube, such as glass, that will allow the maximum amount of UV light to pass through the glass and sterilize the water that is circulating around the UV light-emitting source. Preferably, the sterilization unit ( 56 , 110 ) generates ultraviolet light in the range of approximately 100 nm to approximately 315 nm, which is generally lethal to most organisms within defined exposure times. The UV light kills organisms by destroying essential functions of the pathogen. There are no chemicals involved in the kill rate and there is no resistance potential to the light.
[0077] The UV sterilizer 56 be may configured to treat water that has been elevated above the UV sterilizer 56 , with the water entering the UV sterilizer 56 due to the influence of gravity.
[0078] The sterilization unit ( 56 , 110 ) may be located outside of the cabinet 12 or a UV lamp could be inside the cabinet 12 or container 16 , but preferably has some shielding to block the light so as not to be viewed by any animal or human. In one embodiment, the unit may have an indicator (not shown), such as a light or series of lights that indicate the status and operation of the UV unit. Such indicator would be visible to the user and would inform the user the status of the sterilization unit ( 56 , 110 ), e.g. whether the bulb is working or needs to be replaced.
[0079] The sterilization unit ( 56 , 110 ) may also comprise any one, or a combination of the following: ozone, nanofiltration, nanoheating, magnetic fields, electrolysis, chemical scavenging compounds, silver ions, or other ions that have an acceptable risk/benefit ratio, or filter capable of removing objects smaller than 0.2 microns. For example, the inside surface 42 of the basin 14 , or of container 16 , may be coated with an antimicrobial coating, e.g. micronized silver in an oil-based substrate. This coating may be used in lieu of, or in combination with, UV sterilization unit 56 .
[0080] The present invention is also configured to use one or more filters to remove foreign material and organisms from the flow of water. The filters may be located in between various components, such as upstream from the basin 14 , the pump 50 , and the sterilization unit 56 , and downstream from the sterilization unit 56 . The filters used in the present invention have various functions depending on the location of the filter, e.g. purifying water or as being protective of the pump and or sterilization unit 56 , or additional units such as a refrigerating unit.
[0081] One region having a particular need for filtration is between the outflow from the basin 14 and the pump 50 . A set of set of macro filters may be employed at this area to filter out any large objects such as pet hair that might damage the pump or reduce the efficiency of the pump. In a preferred embodiment, this intake filter needs is configured to be easily replaced while also being easily viewed to ascertain if the filter needs to be cleaned or replaced.
[0082] Another single filter or set of filters may be used between the pump 50 and the sterilization unit 56 to filter out micro objects (see also FIG. 8 below). This would have the tendency to improve the performance of the sterilization unit 56 , particularly the UV sterilizer, which is most effective when there are few objects to potentially block the UV light from a pathogen. Another filter may be provided prior to the water entering into the sterilizing unit 56 is a filter that prevents oxygen and perhaps other gases from entering the sterilizing unit 56 , as pathogens can be shielded from the UV light by a molecule of a gas in the solution being passed through the UV sterilizer.
[0083] Downstream from the sterilization unit 56 and before the water enters the basin 14 it may be desirable to have an additional filter, e.g. an ultra small filter such as a 0.2 micron filter to filter out debris from the destruction of organisms killed by the UV light as the UV light can explode the cell of an organism and the debris from the dead cells can be toxic or harmful to an animal.
[0084] The filter 62 in container 16 may also contain other filtering media, either natural or synthetic, and be in response to the different characteristics of the water in a particular geographic or geological location or also contain substances that can buffer or moderate the pH of the water before the water leaves the canister. The filter 62 could also contain a substance that is desired and would attract otherwise timid animals, such as catnip. The filter 62 may also contain beneficial water-soluble chemicals such as potassium should a veterinarian recommend.
[0085] One or more filters may also be added to remove any undesirable parts of the water that reduce its desirability such as objectionable smell or taste, lack of clarity or other characteristic of the water that causes the animal to reduce the optimal intake of water or even refuse to drink at all. For example, additional filters that may be added to neutralize or normalize the pH or other properties used, or to trap certain common impurities in water, e.g., carbon. A device may be implemented, as available in the art, to add oxygen into the stream of water downstream from the sterilizing unit to support the normal chemistry of the water supply such as in a buffering situation allowing the desirable physical properties of water to be present which will increase the amount of water needed and desired by an animal.
[0086] The present invention is further configured with one or more elements to provide cooling of the water available in the basin 14 . For example, the basin ( 14 , 104 ), the elevated container ( 16 , 132 ), or both may be shaped and composed of materials that facilitate cooling. For example, either the basin ( 14 , 104 ), the elevated container ( 16 , 132 ) may comprise a material such as porous clay or ceramic to cool the water contained in the watering area. The porous material may be used to cool the water that is enclosed by the material due to the water seeping through the porous material and then being evaporated, thereby cooling the water in the matrix of the material and in turn cooling the water inside the structure formed by the material. The temperature most often contours the amount of water that seeps through the material during the firing phase of manufacture of the water station container.
[0087] Furthermore, the walls of the basin 14 and elevated container 12 may be oversized and steep to add additional surface area, furthering evaporation and cooling effect. The basin 14 may also be made of a dense material that could be removed and put into a refrigerator or freezer so that the water temperature of the water within the well could be cooled for many hours, especially if two basins were available and periodically traded out. The porosity can also be controlled or isolated by coating a portion of a surface of a material such as an oil based product which effectively seals the material and prevents water from passing through the material, thus preventing the water from passing through and being available for evaporation. The porous material can be of a natural or synthetic clay source or a wood source or any number of products that will allow a small amount of water to pass through the material and thereby be available for evaporation and the positive and healthy benefits of cool water being made accessible for a pet or other animal to drink.
[0088] In some embodiments, a cooling unit 80 (see FIG. 3 ), such as a fan, refrigeration unit, or like device, may be placed in the cabinet 12 to cool the bowl 14 and water contained therein.
[0089] The tubing 24 , 52 , 60 , 220 , 250 provides for the movement of water without leaking or sweating and also provides for the movement of heat from the water inside the tube, thus promoting the transfer of unwanted heat to the ambient air. A material such as copper might be used if dissipation of heat from the tube to the room air is desired. The tubing will preferably not promote the growth of organisms and may be rigid or flexible as well as allowing for easy removal for cleaning or replacement. Where appropriate, the tubing can also be insulated to prevent heat from being released into the environment when the ambient room temperatures are below the desired temperatures for the water while also having the desired effect to provide heat to prevent freezing. The tubing may also contain or comprise various substances to inhibit the growth of pathogen, e.g. by coating both or either outside and inside surfaces of the tubing, or the material used to manufacture the tubing could have various chemicals to kill pathogens or limit growth of a pathogen and prevent the existence or growth of biofilms.
[0090] The bore size of the tubing (e.g. tubing 52 ) tubing 24 may also be varied to increase or decrease the flow rate and therefore the amount of time that the flow is exposed to the UV light by unit 56 .
[0091] FIGS. 8 and 9 illustrate an alternative pet watering system 200 . System 200 comprises a basin 210 configured for holding a volume of water for feeding an animal or pet. The basin 210 may comprise any number of materials and be configured for cooling as described in the embodiments above. Water in the basin is pumped out via intake tubing 220 to a water treatment unit 240 for sterilization and filtering. The treated water is then directed through outlet tubing 250 to a centrally located pedestal 216 where the water is fed vertically upward to drip or flow downward back into the basin 210 .
[0092] Water exits from pedestal 216 and travels down either two rectangular columns 212 or dome 214 . The dome 214 rests at the top of the pedestal 216 , and functions to offer different water dispersion forms configured to interest an animal to drink. Dome 214 comprises of two somewhat pie-shaped, curves surfaces that direct water coming out of the top of the pedestal 216 to flow down the dome 214 surfaces and generate a sheet of water that falls into the basin 210 . On either side of the pedestal are rectangular-shaped columns 212 that cause water deposited at the top of the pedestal 216 to flow down the columns 212 and provide drips of water, which may be preferable by some animals.
[0093] The opening from the pedestal 216 may be configured to allow water to exit to an elevation greater than the height of the dome 214 and columns 212 , creating a vertical or angled stream, from which an animal could drink directly. The shape of the dome 214 or columns 211 may be configured to provide several types of different amounts and types of falling water, and/or combinations of sheets of water or individual drops, depending on the preferences of a particular animal.
[0094] The pedestal 21 is shown in FIG. 8 as a tube embedded within column 212 . However, the pedestal 216 may be a standalone piece disposed between two separate column members 212 . In this configuration the columns may be removed or modifiable to change the drip or water distribution exiting the pedestal 216 . The columns 212 , when installed, may serve to support the pedestal and prevent an animal from knocking over the pedestal.
[0095] Vertical columns 212 may also comprise a cooling section 222 comprised of water absorbing material that functions to cool the water due to the cooling effect of evaporation. The pedestal 216 may be straight and vertical or coiled and raising vertically. The pedestal 216 is preferably made of a material that easily transmits and transfers the cooling effect of the water being evaporated from the water absorbing material that surrounds the columns 212 .
[0096] The pedestal 216 may keeps its position by virtue of being made of a heavy material, or may be attached to the basin 210 with glue or screws or other means to fasten without harming the purity of the water.
[0097] The treatment unit 240 comprises a pump 234 and sterilization unit 232 that distribute and purify water in the system 200 . A series macro and micro filters 230 may be provided so that the water that re-enters the basin 210 is free of any foreign or disease producing organism or substance, and may be located in between such components such as the basin 210 , the pump 230 , and the sterilization unit 232 and downstream from the sterilizer. The filters 230 are preferably configured to capture debris or organisms that are greater than 0.2 micron in size, and may also be employed and configured to remove some metals that are undesirable, such as mercury or lead.
[0098] The sterilization unit 232 preferably comprises a UV sterilizer as described above, but may also comprise any sterilizer described herein or available in the art.
[0099] The pump 234 may be separate from the basin 210 , or in the basin, and either totally or partially covered by the water in the basin.
[0100] As shown in FIGS. 8 and 9 , treatment unit 240 may be located outside of the basin 210 so as to not generate heat that would be transmitted into the water in the basin. Alternatively, treatment unit may be located inside a cabinet, as shown in FIGS. 1-3 , for aesthetics, or to minimize exposure. The tubing from intake line 220 generally rests below the water line within the basin 210 and extends to the first macro filter 230 of the treatment unit 240 . Beyond the macro filter 230 , water may than pass through a micro filter (not shown) that will filter out very small objects so as not to harm the pump 234 . Another micro filter 230 may be located downstream from the pump 234 . The UV sterilization unit 232 may be in fluid communication with filter 230 , or directly to the pump 234 . Another micro filter 230 may be used downstream from the sterilizer, so that any organisms that were killed in the sterilization unit, e.g. cellular debris, are removed. The sterile and ultra pure water leaving the last micro filter 230 can either enter the basin with a length of tubing that lies inside the basin or can be attached to the bottom of the pedestal 216 .
[0101] The basin 210 functions to hold water for an animal to drink from, as well as provide a base that is difficult to tip over or move in a way that causes spillage. The basin 210 may comprise a material that transfers heat from the water to the ambient room air, as described in the embodiments above. Inversely, the basin 210 may be insulated to keep the cool water contained in the basin from being heated from the ambient room air. The basin may have holes the walls or the bottom that would allow the passage of tubing (e.g. line 150 ) for the outflow or inflow of water from the pump and sterilizing and filtering units. The basin 210 may be of any shape that allows adequate water to be available an extended period of time. The basin 210 may be of a shape or depth that allows the component parts to be included within the basin.
[0102] The shape of the tubing or piping may be circular, elliptical, rectangular, or any other configuration to allow a greater surface area to accelerate the transport of heat or cooling factors via passive or mechanical means to attain a different temperature. Certain sections of the tubing or pipes could be made of a rigid material such as ceramic or other heat transferring material. The tubing may be made with plastic, wood, or any other material and may be one continuous piece or any number of pieces made with one or more different materials to retard or accelerate the dispersion of heat.
[0103] FIG. 10 illustrates yet another embodiment of a pet watering system 300 . In this embodiment, tubing 250 is directed from water treatment unit 240 (as shown in FIG. 9 ) into pedestal 312 , which is centrally located within basin 310 . Pedestal 312 is vertically oriented upward from the bottom of basin 310 and directs water in a fountain-like manner upward and outward into basin 310 . Cooling element 314 may also be coupled to pedestal 314 to facilitate cooling of the water.
[0104] FIG. 11 illustrates a filter overflow scheme that may be utilized with any of the filters used in the various embodiments of the present invention disclosed above. Incoming water from line 250 is directed into first filter 260 via junction 266 . Under normal operation, water passes through filter 260 and output to the pump or sterilization unit. If first filter 260 is obstructed or clogged, the water will bypass to filter 262 and will be directed back to the same output via another junction 266 at the output. A third filter 264 may also be set up in a similar fashion to bypass the first and second filters if obstructed.
[0105] It is appreciated that each of the elements of the multiple embodiments listed above may be used interchangeably, where appropriate, in different embodiments than where the element is illustrated in FIGS. 1-11 . Thus, no one embodiment shall be limited strictly to the elements described, but may be used in combination with other embodiments to meet the objectives of the present invention.
[0106] Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention.
[0107] Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.” | An aseptic watering system for pets is that has a unique filtration and sterilization system for providing a source of drinking water substantially free of toxins, pathogens, resultant metabolic wastes, or other contaminants that may cause bothersome and life threatening diseases. The system also includes means for cooling the drinking water to make it more desirable to a pet. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Application No. 60/375,821, filed Apr. 29, 2002, and titled “SYSTEM FOR LEVERAGING CONCURRENT AUTHENTICATION TO A SECURED SYSTEM,” which is incorporated by reference.
TECHNICAL FIELD
This description relates to leveraging the authentication used to enable access to client/server applications, and more particularly, to the timely determination of the availability of an authenticated session to be leveraged and cross-client leveraging of authentication using a standard web browser.
BACKGROUND
Client/server applications generally include a “client” that runs on an access device (e.g., a personal computer (PC) or a mobile phone) with which the user interacts, and a “server” that runs on a remote server computer. The client and the server typically communicate over a network, like the Internet, by sending messages back and forth to each other.
Client/server applications may or may not incorporate or otherwise leverage a browser. As such, client/server applications may be browser-type applications (e.g., www.aol.com) which generally include a web site accessed using a browser, or non-browser type applications (e.g., AOL Instant Messenger (AIM)) which generally include a desktop client.
Client/server applications may be supported by dedicated client software or they may be supported by client/server software capable of supporting multiple client/server applications. For example a web browser may support one client/server application (e.g., a browser-type application), or it may support multiple client/server applications (e.g., non-browser type applications).
Many client/server applications are designed to support one or more specific individual users such that they necessitate authentication of the particular person interacting with the client. The authentication may be managed by the client/server applications, enabling the users to authenticate themselves with site-specific credentials for each web site.
One common way for the client/server application to manage authentication of its users involves having the client request credentials (e.g., user name and password) from the users. The client then submits the credentials to the server, and the server validates the credentials (e.g., by verifying that the submitted credentials match previously-established credentials known to the server). A successful authentication establishes an application session for the user, which typically persists until terminated by the user (e.g., by logging out or closing the client software); terminated by the client (e.g., automatically after an idle period); or terminated by the server (e.g., the server crashes).
SUMMARY
An authenticated session can be leveraged to permit a user to access multiple client/server applications as a result of a single sign-on experience. Authentication leveraging can be implemented for browser and non-browser clients. For browser clients, authentication leveraging can be achieved using a standard browser, which facilitates integration of authentication leveraging.
When the web site of a secured system is accessed, it may be desirable to quickly determine whether to display an interface soliciting manual entry of user authentication criteria (i.e., whether leveraged authentication may be used to obtain access without manual entry of authentication criteria). Such an interface may be rendered unnecessary if user authentication can be automatically established by leveraging concurrent authentication with another secured system. However, the process of leveraging authentication information from one concurrently authenticated system to the next may result in a delay that may be particularly problematic when the process determines that leveraging is unavailable such that manual entry of user authentication criteria is required after the delay.
Techniques are provided for reducing the delays otherwise experienced by some users during execution of the automated authentication process, including non-authenticated users who will wait only to find that they must manually enter authentication information after they have experienced the delays associated with attempts at automating authentication. Thus, a preliminary and quick inquiry can be made to determine whether a user is likely to be concurrently authenticated into another client/server application (e.g., AIM) from which authentication can be inferred. If no concurrent authentication is likely to be available, an interface can be immediately provided to solicit manual entry of authentication information from the user. However, if concurrent authentication is likely to be available, the user can be instructed to wait while automatic authentication is attempted by, for example, presenting an hourglass icon.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram illustrating components of a system used to enable leveraging authenticated access to a client.
FIG. 2 is a flow chart illustrating initiation and use of leveraged authenticated access.
FIG. 3 is a flow diagram illustrating obtaining initial authenticated access to a non-browser client.
FIG. 4 is a flow diagram illustrating obtaining initial authenticated access to a web-based application through a standard browser.
FIG. 5 is a flow diagram illustrating obtaining authenticated access to a non-browser client after previously being authenticated.
FIGS. 6 and 7 are flow diagrams illustrating obtaining authenticated access to a web-based application after previously obtaining authenticated access to a non-browser client.
FIG. 8 is a flow diagram illustrating obtaining authenticated access to a web-based application after previously obtaining authenticated access to a web-based application using a browser client.
FIG. 9 is a flow chart illustrating a generalized process of obtaining initial authenticated access and leveraged authenticated access.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
Referring to FIG. 1 , a system 100 includes an access device 105 that may be, for example, a personal computer (PC) or a mobile phone. The access device runs an operating system 110 (e.g., DOS, Windows®, Windows® 95, Windows® 98, Windows® 2000, Windows® NT, Windows® Millennium Edition, Windows® XP, OS/2, Macintosh OS, and Linux) and is configured to run different types of client/server applications, such as browser clients accessible using a browser 115 (e.g., Netscape's Navigator and Microsoft's Internet Explorer) and non-browser clients 120 and 125 (e.g., AOL client, CompuServe client, AIM client, AOL TV client, and ISP client). Each of non-browser clients 120 and 125 is associated with a corresponding server 130 or 135 . Similarly, each browser client (or web site) 140 or 145 that is accessed using the browser 115 is defined as a collection of web pages supported by an associated web server 150 or 155 .
The access device 105 communicates with the servers 130 , 135 , 150 and 155 through a network 160 . The network 160 generally provides direct or indirect communication between the access device and the servers. Examples of a network 160 include the Internet, the World Wide Web, WANs (wide area networks), LANs (local area networks), analog or digital wired and wireless telephone networks (e.g., PSTN, ISDN, and XDSL), radio, television, cable, satellite, and/or any other delivery mechanism for carrying data. Connections to the network 160 may include, for example, wired, wireless, cable or satellite communication pathways.
The access device 105 also runs a common local authentication client (CLC) 165 that provides support for obtaining authenticated access to browser and non-browser clients. The CLC 165 is a shared, centralized component that facilitates leveraging of authenticated access to one client to obtain authenticated access to another client. Clients to which authenticated access may be obtained using the CLC 165 may be referred to as CLC-enabled clients. The CLC 165 runs on the access device 105 and interacts with a common authorization web server (CAW) 170 . The CLC 165 may be a standard component of the operating system 110 of the access device 105 , a component added to the operating system 110 , or separate from the operating system 110 . When the CLC 165 is to be added to the operating system but is not part of the operating system, a module that provides the CLC can be added to the operating system using, for example, a client running on the device 105 .
The access device 105 typically includes one or more hardware components and/or software components. As noted above, one example of an access device 105 is a general-purpose computer (i.e., a personal computer) capable of responding to and executing instructions in a defined manner. Other examples include a special-purpose computer, a workstation, a server, a device such as a mobile phone, a component, other physical or virtual equipment, or some combination of these devices capable of responding to and executing instructions.
Using the system 100 , a single sign-on experience can be provided in a client/server environment by leveraging authenticated access to a first CLC-enabled client to enable subsequent authenticated access to other CLC-enabled clients without requiring the user to provide credentials to obtain the subsequent access, and without the delays associated with entering such credentials.
CLC-enabled clients can be browser clients (e.g., web sites such as www.aol.com) and/or non-browser clients (e.g., AIM). Browser clients (i.e., web sites) are accessed using standard browsers (i.e., browsers that are commercially available such as Netscape Navigator or Microsoft Internet Explorer).
Web-based CLC-enabled clients may be accessed through use of a standard web browser. Thus, a standard browser can be used to leverage authenticated access to one CLC-enabled client so as to enable a user to obtain seamless authenticated access to other CLC-enabled clients that ordinarily and otherwise require manual or separate authentication of the user. To obtain leveraged authenticated access, the browser communicates with the CLC 165 , which acts as a common agent through which secure interactions are conducted.
These concepts may be particularly well-suited to enable cross-client authentication (e.g., between AOL's Screen Name Service (SNS) and Microsoft's Passport), to facilitate user access to client applications, and to reduce delays otherwise experienced during an authentication sharing process. Also, by using a standard browser client in the authentication sharing with other client applications, costs associated with supporting browser client modifications (e.g., development, testing, and maintenance of modifications for multiple versions of different browsers on multiple platforms) can be avoided.
In a general implementation, authentication sharing is enabled between multiple CLC-enabled clients, including browser and non-browser clients. To begin, a user initiates authentication into a client that may be a browser client (i.e., a web site such as www.aol.com) or a non-browser client (i.e., AIM). When successfully authenticated, the user can leverage the authentication to enable simplified access to other clients, which may be browser clients or non-browser clients, by leveraging the initial authentication. Interactions between clients are simplified, since each client only needs to support one authentication sharing interface. In particular, each CLC-enabled non-browser client can be updated with the interaction protocol of the CLC 165 . Thus, rather than having each non-browser client support an interface with each other non-browser client, the CLC 165 and the non-browser clients share a protocol. The CLC 165 also includes a mini-HTTP server to enable communication with the standard browser so as to support CLC-enabled browser clients.
For purposes of supporting access by CLC-enabled browser clients, the CLC 165 can register with the operating system 110 to handle a URL protocol that leverages the browser in launching the CLC 165 in response to receipt of a call to a URL corresponding to the CLC 165 (i.e., to initiate a CLC session when the CLC 165 is not already running). Access and communications with the CLC 165 can be made with a user-specific channel if the HTTP server of the CLC 165 is available to other users of the access device.
Referring to FIG. 2 , authenticated access to CLC-enabled clients may be obtained according to a procedure 200 . Initially, a CLC-enabled client is launched ( 205 ). Launching a CLC-enabled client may include clicking on a link corresponding to a web site 140 or 145 (i.e., a browser client) while using the browser 115 or simply selecting a non-browser client 120 or 125 directly using a non-browser interface at the access device 105 (e.g., selecting an icon having a link to the non-browser client). As discussed in detail below, the operations performed vary based on whether the CLC-enabled client is a browser client or a non-browser client.
When a CLC-enabled client is launched, an inquiry is made as to whether a CLC session is available ( 210 ). For both browser and non-browser applications, this inquiry involves polling the operating system 110 to determine whether the CLC 165 is running. If no CLC session is available, user credentials (e.g., user name and password) are requested from the user ( 215 ). The user credentials then are used to provide authenticated access to the CLC-enabled client ( 220 ). In addition, since no CLC session was previously detected, a CLC session is initiated ( 225 ). The CLC session generally remains available until all clients running in the session are terminated (e.g., by having the user actively sign off from the clients or by having access to the clients time out). In certain implementations, a user who signs off from a CLC-enabled client may be given the option of terminating the CLC session and/or termination of all CLC-enabled clients associated with the session in addition to just signing off from the client. Termination of the CLC session means that a subsequent attempt to access a CLC-enabled client will require the user to provide credentials. If the inquiry ( 210 ) indicates that the CLC session is available, authenticated access to the CLC-enabled client is provided based on the existence of the CLC session ( 230 ). Thus, the user is able to leverage a prior authenticated access to a CLC-enabled client to obtain authenticated access to a different CLC-enabled client, and is not required to enter credentials again to access the different client.
A more detailed discussion of obtaining authenticated access now is provided with reference to FIGS. 3-7 .
FIG. 3 illustrates how the access device 105 may be used to obtain initial authenticated access to a CLC-enabled non-browser client (e.g., non-browser client 120 ). Initially, a user 300 launches non-browser client 120 by, for example, double-clicking on an icon corresponding to the client 120 ( 305 ). The non-browser client 120 may correspond, for example, to the AIM client.
Upon being launched, the client 120 sends an inquiry to the operating system 110 to determine whether the CLC 165 is running and has an active authenticated session ( 310 ). As this is an initial authentication, the CLC 165 is not running and the operating system 110 responds by launching the CLC 165 ( 315 ). The CLC 165 then sends a reply indicating that an active authenticated session is not available ( 320 ). Upon receiving the reply from the CLC, the client 120 presents a login form to the user ( 325 ), and the user responds by entering his credentials ( 330 ), which may be, for example, a user name and a password. By checking whether the CLC 165 is running and has an active session, the process provides a very quick (e.g., on the order of milliseconds) determination of whether leveraged authentication is likely to be achieved. When the CLC does not have active authenticated session available, this determination lets the process quickly present the login form and thereby avoid delays in presenting the form that might occur in the event of a longer process for determining whether leveraged authentication is likely to be available.
The client 120 then submits the credentials and an application identification to the CLC 165 ( 335 ), which submits the credentials to the CAW 170 ( 340 ). The credentials are submitted along with an application identification (i.e., an identification that designates the client 120 ) that may include, for example, a version number.
The CAW 170 validates the user's credentials and the application identification ( 345 ). For example, the CAW 170 may check the application identification to determine whether the version of the application can be trusted. In other implementations, this validation may be performed by the CLC 165 .
The validation of the user's credentials may include consulting a table of credentials to obtain credential information specific to, for example, the user or the application. For the purposes of this example, it is assumed that the user has a common user name and password that may be used to access all CLC-enabled non-browser clients and browser clients (i.e., web sites) of interest. In actual implementations, the table may maintain multiple user name/password combinations to permit a single user to access different clients, as well as user name/password combinations for other users.
After the user's credentials and the application identification are validated, the CAW 170 generates a CLC master authentication token and an application token ( 350 ). The CAW 170 then passes these tokens to the CLC 165 ( 355 ). The CLC 165 stores the CLC master token ( 360 ) and sends the application token to the client 120 ( 365 ). The client 120 sends the application token to the server 130 that supports the client 120 ( 370 ). The server 130 decrypts the application token to decrypt and validate the credential information (i.e., the user authentication data) necessary to access the client 120 ( 375 ). The server 130 then establishes an authenticated session to permit the user to access the client 120 ( 380 ).
FIG. 4 illustrates an alternative situation in which the initial authenticated access is obtained to a CLC-enabled browser application (e.g., web site 140 hosted by web server 150 ) through the browser 115 . Initially, the user 300 uses the browser 115 to navigate to the web site 140 , which, in this example, is www.mynetscape.com ( 400 ). The browser 115 responds by requesting a web page from the server 150 ( 405 ). In response to the request, the server returns the web page, which includes a login button ( 410 ).
The user then clicks on the login button of the web site to sign into the web site ( 415 ), and the browser 115 sends a request for a login page to the CAW 170 ( 420 ). Since the web site 140 is a CLC-enabled client, the CAW 170 returns a pre-login page to the browser 115 to instruct the browser 115 to check whether leveraging a prior authenticated CLC session is possible ( 426 ), and the browser 115 sends a request to the CLC 165 to make such a check ( 428 ). In this case, the CLC is not running and leveraging a concurrent authentication session in a non-browser client is not possible. Accordingly, the CLC 165 is launched and responds that no session is available (or the CLC does not respond or the operating system 110 responds that the CLC is not running) ( 430 ).
Since no prior authenticated access is available for leveraging, the browser 115 requests a login form from the CAW 170 ( 432 ), the CAW provides a login form ( 434 ), and the browser renders the login form ( 440 ). The check for a CLC session lets the process quickly present the login form and thereby avoid delays in presenting the form that might occur in the event of a longer process for determining whether leveraged authentication is likely to be available. If an available CLC session had been available, the CLC session would have been used and the login page would not have been sent.
In response to the rendered login form, the user enters his login credentials ( 445 ), and the browser submits the credentials and the web site application identification to the CAW 170 for verification ( 450 ). After the CAW 170 validates the credentials and the web site application identification ( 455 ), the CAW 170 generates a master browser token and a web site browser token ( 460 ). The CAW 170 then passes the tokens to the browser 115 ( 465 ). The browser stores the browser master token ( 470 ) and forwards the web site application token to the server 150 supporting the selected web site 140 ( 475 ). The web server 150 decrypts the web site application token and extracts user authentication data ( 480 ). Finally, the web server 150 uses the user authentication data to establish an authenticated session in the web site ( 485 ).
FIG. 5 illustrates how a user obtains authenticated access to a CLC-enabled non-browser client after having previously initiated a CLC session by obtaining authenticated access to a CLC-enabled browser client or a CLC-enabled non-browser client during the same session. Initially, the user launches a CLC-enabled non-browser client, such as non-browser client 125 ( 505 ). The non-browser client 125 sends an inquiry to the operating system 110 to determine whether the CLC 165 is already running and has an active authenticated session available ( 510 ). Since the CLC 165 is running and an authenticated session is available (since the user has already obtained authenticated access to the non-browser client 120 ), the CLC sends a reply to this effect ( 515 ). (In the discussion of FIG. 3 , the CLC inquiry ( 310 ) was referred to as an inquiry to the operating system; the descriptions of the CLC inquiries ( 310 ) and ( 510 ) are both accurate descriptions of the same event. In both cases, a call is made to the CLC 165 . In particular, when the CLC is not running (as in the situation discussed with respect to FIG. 3 ), this call is processed by the operating system, which launches the CLC so that the CLC can reply. By contrast, when the CLC is running, the call is processed by the CLC.)
Non-browser client 125 passes its application identification to the CLC 165 and requests an application token ( 520 ). The CLC 165 submits the application identification and the CLC master authentication token to the CAW 170 and requests an application token from the CAW 170 ( 525 ). The CAW 170 verifies the CLC master authentication token and the application identification ( 530 ).
If the CLC master authentication token and the application identification are valid, the CAW 170 generates an encrypted application token ( 535 ) and passes the application token to the CLC 165 ( 540 ). The CLC 165 passes the encrypted application token to the non-browser client 125 ( 545 ). The non-browser client 125 passes the encrypted application token to its associated server 135 ( 550 ). The associated server 135 decrypts the application token to extract user authentication data ( 555 ), and uses this data to establish an authenticated session for the user ( 560 ). Thus, the session is established without requiring the user to enter credentials to establish the session.
FIG. 6 illustrates how a user obtains authenticated access to a CLC-enabled web-based client through a browser after previously obtaining authenticated access to a non-browser client during the same session. Initially, the user navigates to the web site 140 , which, in this example, is www.mynetscape.com ( 600 ). The browser 115 responds by requesting a web page from the server 150 ( 605 ). In response to the request, the server returns the web page, which includes a login button ( 610 ).
The user then clicks on the login button of the web site to sign into the web site ( 615 ), and the browser 115 sends a request for a login page to the CAW 170 ( 620 ). Since the web site 140 is a CLC-enabled client, the CAW 170 returns a pre-login page to the browser 115 to instruct the browser 115 to check whether leveraging a prior authenticated CLC session is possible ( 625 ), and the browser 115 sends a request to the CLC 165 to make such a check ( 630 ).
In this case, leveraging a concurrent authentication session is possible (i.e., an active CLC session is available). Accordingly, the CLC 165 responds by indicating that an available authenticated session exists ( 635 ).
The browser 115 then requests master and website browser tokens and sends a web site identification with the request ( 640 ). The CLC forwards the request and the web site identification to the CAW 170 along with the CLC master token ( 645 ).
The CAW 170 validates the CLC master authentication token and the web site identification ( 650 ). If the validation of the CLC master authentication token is successful, the CAW 170 generates an encrypted browser master authentication token and an encrypted web site application token ( 655 ) that the CAW 170 passes to the browser 115 ( 660 ).
The browser 115 stores the browser master authentication token as a cookie ( 670 ). The browser 115 also requests a web site login page from the server 150 and sends the web site browser token along with the request ( 675 ). The web server 150 decrypts and validates the web site browser token ( 680 ). Upon successful validation, the web server 150 establishes an authenticated session ( 685 ).
FIG. 7 illustrates an alternative to the approach of FIG. 6 to permitting a user to obtain authenticated access to a CLC-enabled web-based client through a browser after previously obtaining authenticated access to a non-browser client during the same session. Initially, the user navigates to the web site 140 ( 700 ). The browser 115 responds by requesting a web page from the server 150 ( 705 ). In response to the request, the server returns the web page, which includes a login button ( 710 ).
The user then clicks on the login button of the web site to sign into the web site ( 715 ), and the browser 115 sends a request for a login page to the CAW 170 ( 720 ). Since the web site 140 is a CLC-enabled client, the CAW 170 returns a pre-login page to the browser 115 to instruct the browser 115 to check whether leveraging a prior authenticated CLC session is possible ( 725 ), and the browser 115 sends a request to the CLC 165 to make such a check ( 730 ).
In this case, leveraging a concurrent authentication session is possible (i.e., an active CLC session is available). Accordingly, the CLC 165 responds by indicating that an available authenticated session exists ( 735 ).
The browser 115 then sends a request to the CAW 170 for a leveraged authentication login ( 740 ). The CAW 170 responds by generating a random number R and an encrypted cookie containing R ( 742 ) that the CAW 170 returns to the browser ( 744 ). The browser sends R to the CLC 165 using a local, user-specific protocol ( 746 ) and the CLC 165 temporarily stores R ( 748 ).
The browser 115 also requests a browser token and sends R using the HTTP protocol ( 750 ). The CLC 165 compares the two Rs to verify that the request for the browser token is from the local browser 115 ( 755 ).
Upon successfully verifying the request, the CLC 165 requests a browser token ( 760 ). In response, the CAW 170 generates ( 762 ) and returns ( 764 ) and encrypted browser token. The CLC 165 forwards the encrypted token to the browser 115 ( 766 ).
The browser 115 passes the web site application identification and the browser token to the CAW 170 ( 770 ). The CAW 170 checks the browser token, random number, and time stamp ( 772 ). If any of the checks fail, the CAW 170 responds with an error message and a login form with which the user can manually enter login credentials ( 774 ). The checks performed by the CAW 170 include reading and decrypting the cookies, comparing the passed values of the random number to ensure they match, and checking the timestamp in the browser token to ensure the token has not expired.
If the checks are successful, the CAW 170 extracts the CLC master authentication token from the browser token and validates the CLC master authentication token ( 780 ). If the validation of the CLC master authentication token is successful, the CAW 170 generates an encrypted master browser token and an encrypted web site browser token ( 782 ) that the CAW 170 passes to the browser 115 ( 784 ).
The browser 115 stores the browser master authentication token as a cookie ( 786 ). The browser 115 also requests a web site login page from the server 150 and sends the web site browser token along with the request ( 790 ). The web server 150 decrypts and validates the web site browser token ( 792 ). Upon successful validation, the web server 150 establishes an authenticated session ( 794 ). FIG. 8 illustrates how a user obtains authenticated access to a web-based client through the browser 115 after having previously obtained authenticated access to a web-based client during the same session (i.e., after the user has completed an initial authentication into a web application through a browser client as discussed above with respect to FIG. 3 or after the user has completed authentication into a web application through a browser client subsequent to an initial authentication into a non-browser client as discussed above with respect to FIGS. 6 and 7 ).
Initially, the user navigates to the web site 145 ( 800 ). The browser 115 responds by requesting a web page from the server 150 ( 805 ). In response to the request, the server returns the web page ( 810 ).
Since the web site 145 is a CLC-enabled browser client, and since the browser 115 has previously saved a master browser cookie in response to obtaining authenticated access to another CLC-enabled browser client, the browser requests a login page from the CAW 170 ( 815 ). The browser accompanies the request with the master browser cookie and a web site identification for the web site 145 .
The CAW 170 receives and verifies the browser master authentication token and the web site identification ( 820 ). If the browser master authentication token and the application identification are successfully validated, the CAW 170 generates ( 825 ) and returns to the browser 115 ( 830 ) an encrypted web site browser token.
The browser 115 requests a web site login page from the server 155 and sends the web site browser token along with the request ( 835 ). The web server 155 decrypts and validates the web site browser token ( 840 ). Upon successful validation, the web server 150 establishes an authenticated session ( 845 ).
FIG. 9 illustrates a generalized description of a process 900 of establishing an initial authenticated session or establishing an authenticated session by leveraging an established authenticated session. Initially, a user of an access device launches a client application ( 905 ). Launching a client application may include launching a non-browser client such as, for example, AIM. Launching a client application also may include using a browser to navigates to a web site such as, for example, www.aol.com or www.mynetscape.com.
The client checks whether a common agent (e.g., the common local authentication client (CLC)) is running ( 910 ). In general, the common agent is either (1) not running, (2) running with an available authenticated session, or (3) running without an available authenticated session.
If a common agent is not running with an available authentication session, the user is prompted for and enters login credentials ( 915 ). The login credentials and an application identification then are passed to the common agent web server (CAW) ( 920 ), which validates the login credentials and the application identification ( 925 ).
Upon successful validation, the CAW generates component tokens, such as a common agent master authentication token, a browser master token, and a client application token ( 930 ). The client application token is specific to the non-browser client or web-based client (i.e., the web site). The CAW then passes the client application token to the client, which passes the token on to its supporting server, and passes the common agent master authentication token and the browser master token to their respective components ( 935 ).
The server supporting the client decrypts the client application token and extracts user authentication data ( 940 ). The server then uses the authentication data to establish an authenticated session ( 945 ).
If a common agent is running ( 910 ), then there is a check for an available authenticated session ( 950 ). If an authenticated session is not available, then the situation is treated as above following on from where the user enters login credentials ( 915 ) to establish an authenticated session.
If an authenticated session is available, the CAW verifies component tokens ( 955 ). For instance, depending on the client to which authenticated access is being sought, the CAW may validate the common agent master authentication token or the browser master token. Upon successful validation, the CAW generates an encrypted client application token that is specific to the non-browser client or the web-based client being accessed ( 960 ). The CAW then sends this token to the server supporting the client ( 965 ). As discussed above, the server supporting the client decrypts the client application token and extracts user authentication data for use in establishing an authenticated session ( 940 and 945 ).
One specific example of an implementation uses SNS (“Screen Name Service”) as the secured system to which authentication is desired by a user device, and AIM as the secured system from which authentication is leveraged. However, these references are merely exemplary and should not be deemed limiting of the concepts described.
Initially, SNS determines whether a local server exists to facilitate automated authentication, and does so, for example, by sending a request to the user device. For example, SNS may make a request to a local server (e.g., CLC) at the user device by way of a browser of the user device.
If the user device responds that no local server exists for servicing the request, SNS aborts the automated authentication process and proceeds to request authentication information from the user manually. SNS may do so, for example, by sending a HTML interface to the browser. (In certain implementations, SNS may use a lack of a reply from the user device as evidence that no local server exists.) The process of determining whether a local server exists typically takes just milliseconds, and avoids delays that may otherwise be experienced by unauthenticated users.
If the user device responds with an indication that a local server exists, SNS proceeds to attempt automated authentication and to inform the user of potential delays caused by this process, if necessary. SNS may inform the user of potential delays through use, for example, of an hourglass icon.
In a specific implementation, a user uses the browser of the user device to enter the URL of a secured site that the user wants to access. The browser processes the URL in an attempt to access the secured site. The secured site, upon determining that the user is not authenticated, initiates a process to determine whether user authentication can be inferred. For example, the secured site may itself perform the following process steps, or it may communicate with a centralized authentication service (e.g., SNS or some other master authentication site/service) that will perform the negotiations. The latter is assumed for purposes of the following discussion.
SNS receives the request for access by the user to the secured system, and determines whether the local device includes a server that is available for leveraging user authentication with another secured system. This is accomplished by submitting a request (in the form of an image tag) to the local server, and determining whether the local server is available to attempt negotiations based on whether the local server responds to the request.
In response to a request for access by the user, SNS supplies an HTML page that includes an embedded image tag to the browser of the requesting user device for rendering. Conventional image tags typically specify a machine ID, a port, and a path, which collectively correspond to a location of information appropriate for loading a requested image. In this case, the machine ID specified by the image tag corresponds to the user device, and the port specified by the image tag corresponds to a standard port for local cooperative authentication servers running at that user device.
Specifically, IP address=127.0.0.1 is universally recognized as corresponding to local client devices. Therefore, if an HTML page to be rendered by a browser includes an embedded image tag with a machine ID corresponding to IP=127.0.0.1, the browser at the user computer will seek information for rendering the image locally.
The port specified by the image tag corresponds to a port being monitored by a server on the local user device. The server is typically an extension to an existing non-browser client, such as AIM, that has already authenticated the user. As such, the server is generally installed with the client, and is activated and deactivated with the client.
The path for the image tag indicates which (of presumably several) resources should be rendered in satisfaction of the request by the local server located at the designated device and port. A first standard path is typically used for initial checking for existence of the server, and one or more additional standard paths are typically used during actual authentication interactions.
The browser of the user device perceives the HTML page request from SNS, reads the image tag associated with an image request within the HTML page request, and identifies the port associated with the image tag.
The server at the user device is configured to monitor/service traffic over the specified port of the user device. This local server is generally configured to accept authentication related requests only from the local user device. The server therefore perceives the requested URL within the embedded tag, accesses a small image (e.g., a 10×10 pixel image) that is stored locally, for example, in anticipation of such a requested URL, and responds by sending the small image to be loaded by the browser into the HTML page.
The browser receives the information for loading the image tag, loads the image into the HTML page, and displays the image. However, as indicated, the image is small (e.g., a 10×10 pixel image) and may be otherwise discretely configured. Conventional browsers support such loading, and special extensions to existing web browser technology are not required to display the image-loaded page which, in this example, is a mere dot which quickly vanishes in steps that follow.
Javascript (JS) at the browser determines whether an image was received, which indicates whether the potential for leveraging authentication exists. In particular, the successful retrieval of the 10×10 image indicates the potential for leveraging authentication exists. Note that this support is also standard in all web browser's support of JS, and no browser extension is required.
The JS then conditionally either replaces the displayed page with a manual login page or with a page that will proceed to automatically interact with the local server to complete the authentication process. The replacement is accomplished either by directing the browser to contact the SNS server to acquire alternate content, or by selecting alternate content (e.g., content containing JS) that was loaded as part of the initial page. Again, no extension to standard web browser JS functionality is necessary for this process.
If the local server is deemed available for negotiating whether to leverage user authentication to another secured system, such negotiations are initiated and, if necessary, the user is informed of the potential for delays that will be experienced during the negotiation of authentication information. Otherwise, if the local server is not deemed available, the user is presented with a user interface that enables manual entry of authentication information without further delays related to leveraging of user authentication to alternative secured systems.
The process for deciding between automatic and manual authentication typically takes less than a second. As such, the SNS is quickly provided with information that enables a decision as to whether manual entry of authentication will likely be required of the user, thus necessitating the presentation of an interface HTML page soliciting that information. Alternatively, SNS will proceed with automated authentication and merely provide to the user, if necessary, an indication of this process (e.g., an hourglass) or of potential delays that may be experienced during this process.
In an example of automated authentication, the following process may be performed if an image is returned by a server at the local user device to the browser of that device in response to an image tag provided by SNS. Effectively, the following process enables user access to the desired secured site without manual entry of user authentication credentials.
SNS sends a request to the browser to load another HTML page. This HTML page also embeds an image tag, and the image tag again specifies the local machine (IP=127.0.0.1) and the port of the local server on that machine. In addition, this tag also specifies a path (e.g., a URL) that differs from the image tag originally sent (and described above).
The browser receives the requested HTML page and directs the image tag to the local server for loading. The local server perceives the image tag and looks for the particular path associated with the image tag. The local server is pre-configured to generate a consequential request in response to the path specified in this image tag. The request specifies the local server identity, and requests authentication credentials from the AIM host. The request is directed from the local server to another secured system (e.g., AIM) for leveraging of previous authenticated access to that system.
The AIM host server receives the request from the local server and provides encrypted credentials (e.g., a number that is understandable only to the AIM host). The local server receives the encrypted credentials from the AIM host, and responds to the image tag request from the browser by redirecting the browser to seek satisfaction of the image tag from SNS. The local server redirects the image to the URL at SNS as a matter of course, preventing the local server from being lured into leaking credential information to any site or service other than the true SNS server.
The browser then requests an image from SNS based on the image tag originally provided by SNS. In addition, because a number representing the encrypted (or encoded) credentials is embedded in the redirection instruction provided from the local server to the browser, they also are provided to SNS with the request. Note that the number may not be reflective of the credentials themselves, but may instead be used to enable a lookup of those credentials.
SNS recognizes the image tag based on the embedded path (e.g., the URL). Accordingly, SNS knows to look for the number representing encrypted credentials that is provided with the redirected image tag.
SNS locates the encrypted credentials within the image tag, and authenticates the user based on the existence of the number. However, because this process began with SNS requesting an HTML page that includes an image, the process includes a response by SNS to the redirected image tag with a cookie that is based on the encrypted credentials. The browser then builds the cookie into the HTML page that is returned to the SNS server to conclude the request. SNS may solicit additional information (e.g., a screen name) from the browser, and may process that information.
The shared authentication technique and protocol provide secure and accurate identification of the users of the system and prevent users from impersonating other users. To prevent impersonation through misuse of the shared authentication system, token forgery and tampering are prevented, user login names are protected, unauthorized web sites are prevented from obtaining authentication tokens, unauthorized replay of authentication tokens is prevented, and access to authentication tokens is restricted. To prevent token forgery and tampering with authentication tokens, where a hacker forges or modifies a token to impersonate another user, tokens may contain a checksum of their contents and may be encrypted with a secret key that is unknown to the hacker. As a result, hackers cannot modify existing tokens or forge new tokens undetected. To prevent third party applications from obtaining a user's login name (and potentially violating a user's privacy), the authentication token may be encrypted and may be validated on the server side. The client application may not have direct access to the token information and may be prevented from getting a user's login name directly.
Transmission of an authentication token from the CLC to the authenticated system's web server using a browser client prevents a hacker's web page from being able to request and obtain an authentication token from the common agent and thereafter pass the token to the hacker's web server. Rather, the token is passed from the common agent to the authenticated system's web server as query data on an authenticated system web server URL returned to the browser from the common agent in the form of an HTTP redirect in response to an image request. Even if a hacker is able to return a hacked web page containing the common agent token-request URL, the returned token is not exposed to JavaScript or otherwise available to the hacker's web page, and hence is not available to the hacker to send back to his server. Alternatively, network packet sniffers that capture tokens as the tokens come across the network are blocked from capturing authentication tokens by only communicating tokens across SSL connections.
Unauthorized token replay (i.e., unauthorized use of a token captured from another user) may be prevented by including a timestamp within the token to indicate when the token was generated. Servers that receive and process the tokens may reject tokens that are older than a configurable maximum age to restrict the amount of time during which a captured token can possibly be replayed. Also, the tokens may include a random number that must also be present in an encrypted cookie that is only readable and writable by the authentication system's web server on the user's browser. Once the cookie is stored on a user's browser, the cookie is not accessible to the hacker's web pages or web server.
Access to authentication tokens to the current, local user session may be restricted by stipulating that authentication tokens are sent to and from the common agent through browser interactions with a URL protocol handler registered to the common agent at the operating system level, and implementing the common agent's URL protocol handler in such a way that only requests from the current local user session are processed and other requests (e.g., requests from a remote user on the same system) are rejected.
A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, subsequent authentication may be into a non-browser client from a browser or subsequent authentication may occur in parallel or in a spoke-like manner, rather than serially (linearly), as described above. Accordingly, other implementations are within the scope of the following claims. | Leveraging an established authenticated session in obtaining authentication to a client application includes receiving a request for access to a client application requiring authentication of a requestor and determining whether there exist characteristics of leverageable authentications corresponding to established sessions having an authenticated state at a time of the determination. When the determination reveals characteristics of at least one leverageable authentication corresponding to an established session, and attempt is made to obtain access for the requester to the client application based on the at least one leverageable authentication, and the requestor is provided with a notification related to the attempt to obtain access for the requester to the client application. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Phase Entry of International Application No. PCT/IB2011/054974, filed on Nov. 8, 2011, which claims priority to French Patent Application Serial No. 1059335, filed on Nov. 12, 2010, both of which are incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to thermoreversibly cross-linked graft polymers. These polymers find an application in numerous fields, and for this reason the present invention also relates to the use of said graft polymers in coatings, paints, thermoplastics, glues, lubricants, fuels, inks, cements, construction materials, rubbers and bitumens. In particular, the invention relates to bitumen/polymer compositions based on bitumen and said graft polymers. Finally the invention relates to the processes for preparing the graft polymers and bitumen/polymer compositions based on bitumen and said graft polymers.
BACKGROUND
[0003] The graft polymers according to the invention are polymers capable of self-assembly, in order to form a supramolecular network via a system of thermoreversible cross-linking. The graft polymers according to the invention are not linked together via covalent bonds, bonds which once formed cannot be broken and which are therefore irreversible, but are linked together via thermoreversible bonds, i.e. which are present in a certain temperature range and disappear in other temperature ranges. This can be particularly advantageous in the technology of coatings in which there is a need for polymers having a low viscosity under high-spead shearing during their application and which become viscous again after their application. This is particularly true in the field of bitumens. To be capable of use, the bitumen must have certain mechanical properties and in particular elastic or cohesive properties. Since bitumen on its own is generally not sufficiently elastic or cohesive, polymers which can optionally be cross-linked, in particular with sulphur, are added. When these polymers are cross-linked, the cross-linking is irreversible. Once the cross-linking has been carried out, it is not possible to return to the initial state that existed before the cross-linking reaction. The cross-linked bitumen/polymer compositions therefore have good mechanical properties, but a very high viscosity. A need therefore exists for polymers having an association between polymer chains which is thermoreversible.
[0004] Some examples of associations between molecules which lead to supramolecular polymers exist in the literature. Patent EP0929597 describes supramolecular polymers based on units having ureido-pyrimidone groups. Patent EP1031589 describes supramolecular polymers obtained by reaction between molecules containing isocyanate functions and molecules containing hydroxy, amine or acid functions. Patent Application EP1136506 describes supramolecular polymers based on units with glutarimide functions. Patent EP1202951 describes supramolecular polymers obtained by reaction between an acid or acid chloride with an aromatic derivative substituted by hydroxyl and acid functions. Patent EP1465930 describes supramolecular polymers based on units having imidazolidinone groups. Patent application EP2069422 describes supramolecular polymers originating from the reaction between imidazolidinone derivatives and fatty acid derivatives.
[0005] The Applicant has itself developed the supramolecular polymers described in patent applications EP2178924, EP2178925 and EP2217648. The former are based on graft polymers with thiol functions and the latter are obtained by the reaction between mixtures of polymerized fatty acids and molecules comprising urea, amide, urethane or imidazolidinone units. In application EP0799252 by the Applicant, functionalized elastomers are described. These elastomers are functionalized by dithiol derivatives also comprising acid functions which induce cross-linking via hydrogen bonds. The addition of amines can also induce additional cross-linking of the ionomer type.
[0006] In patent applications EP2178924 and EP2178925, the process for the preparation of graft polymers involves a polymer and a thiol derivative comprising a long hydrocarbon chain of at least 18 carbon atoms. Although the grafting process works correctly with a thiol derivative of 18 carbon atoms, with the grafting yield ranging from 60% to 80%, the grafting processes involving longer thiol derivatives such as those comprising a long hydrocarbon chain of 40 carbon atoms or 70 carbon atoms are less satisfactory, as the grafting yields are only 20%. Moreover it is very difficult to separate the graft polymers with grafts of 40 carbon atoms or 70 carbon atoms from unreacted thiol derivatives, which can considerably modify the properties of the graft polymers obtained. It is therefore difficult to obtain graft polymers with very long paraffinic domains and this is what the Applicant has in particular sought to improve.
SUMMARY
[0007] In continuing its research, the Applicant has now developed novel graft polymers that can be obtained more easily, while retaining a graft having a paraffinic domain of very great length. Moreover the novel graft polymers have improved thermoreversibility properties due to the introduction of a novel function within these graft polymers. Thus, the novel graft polymers formed particularly effective gels, in particular in an organic solvent such as toluene and also in bitumen. The grafting yield is greater than those obtained previously, with an equivalent quantity of carbon atoms on the graft. The gel formed by the novel graft polymers is present in a certain temperature range and disappears when the temperature rises. The novel graft polymers according to the invention are therefore capable of inducing thermoreversible cross-linking.
[0008] Moreover, the Applicant has also developed novel bitumen/polymer compositions having, at the temperatures of use, the properties of the irreversibly cross-linked bitumen/polymer compositions, in particular as regards elasticity and/or cohesion, and having a reduced viscosity at implementation temperatures. Finally, another subject of the invention consists of providing bitumen/polymer compositions which are stable when stored and resistant to aging.
[0009] The novel graft polymers according to the invention are polymers GP comprising a main polymer chain P and at least one side graft G connected to the main polymer chain P, the graft G having general formula (1):
[0000] —S—R 1 —X—R 2 (1)
[0000] with:
R 1 and R 2 which represent independently of one another, linear or branched, unsaturated or saturated hydrocarbon groups, such that the total number of carbon atoms of the R 1 and R 2 groups is comprised between 2 and 110, X which represents an amide, amido-acid, ester, imide, urea or urethane function, said graft G being connected to the main polymer chain P via the sulphur atom.
[0012] The presence of the R 1 and R 2 groups allows thermoreversible cross-linking via crystallizable paraffinic domains. At low temperature the interactions of the crystalline zones of the R 1 and R 2 groups combine the polymer chains P, the graft polymer GP is then cross-linked. When the temperature increases, these crystalline zones melt and the cross-linking, the combination of the polymer chains P, disappears. When the temperature decreases again, the R 1 and R 2 groups recrystallize and the cross-linking reappears. The cross-linking is therefore thermoreversible.
[0013] Moreover the presence of the X function in the polymer GP makes it possible to reinforce the thermoreversible cross-linking via interactions of the hydrogen bond type or via polar interactions. At low temperature, these interactions make it possible to reinforce the combination, the cross-linking, of the polymer chains P. When the temperature increases, these interactions disappear, as does the cross-linking, the combination of the polymer chains P. When the temperature decreases again, these interactions reappear, as does the cross-linking. These two types of interactions induce a synergistic effect with respect to the cross-linking of the polymer GP.
[0014] Finally, as the thermoreversible cross-linking is promoted by R 1 and R 2 groups comprising a large number of carbon atoms, the novel graft polymers make it possible due to a two-step synthesis process, in which firstly the R 1 group is introduced then the R 2 group, to more easily obtain said graft polymers GP with grafts having very long chain lengths. It is in fact more difficult to synthesize a graft polymer GP comprising a single hydrocarbon group than two hydrocarbon groups, with an equal number of carbon atoms. The Applicant has also found that novel graft polymers with small-sized grafts, i.e. grafts comprising short chains, could be synthesized.
[0015] The invention relates to a graft polymer GP comprising a main polymer chain P and at least one side graft G connected to the main polymer chain P, the graft G having general formula (1):
[0000] —S—R 1 —X—R 2 (1)
[0000] with R 1 and R 2 which represent independently of one another, linear or branched, unsaturated or saturated hydrocarbon groups such that the total number of carbon atoms of the R 1 and R 2 groups is comprised between 2 and 110, X which represents an amide, amido-acid, ester, imide, urea or urethane function, said graft G being connected to the main polymer chain P via the sulphur atom.
[0016] Preferably, the total number of carbon atoms of the R 1 and R 2 groups is comprised between 4 and 90, preferably between 8 and 70, more preferentially between 12 and 50, even more preferentially between 16 and 40, even more preferentially between 18 and 30, even more preferentially between 20 and 24. Preferably, R 1 represents a linear, saturated hydrocarbon group, of formula C n H 2n and R 2 represents a linear, saturated hydrocarbon group of formula C m H 2m+1 with n and m being integers such that the sum n+m is comprised between 2 and 110. Preferably, n is comprised between 1 and 60, preferably between 2 and 50, more preferentially between 4 and 40, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12 and m is comprised between 1 and 50, preferably between 2 and 40, more preferentially between 4 and 30, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12.
[0017] Preferably, the main polymer chain P results from the copolymerization of conjugated diene units and monovinyl aromatic hydrocarbon units, in particular from the copolymerization of butadiene units and styrene units. Preferably, the content of 1-2 double bond units originating from the conjugated diene, in particular butadiene, is comprised between 5% and 70% by mass, with respect to the total mass of the conjugated diene units, in particular butadiene, preferably between 10% and 60%, more preferentially between 15% and 50%, even more preferentially between 18% and 40%, even more preferentially between 20% and 30%, even more preferentially between 22% and 25%. Preferably, X represents an amide function and the general formula (1) is as follows:
[0000]
[0018] The invention also relates to a process for the preparation of the graft polymer as defined above, in which the following are reacted, in a first step, at least one polymer P and at least one thiol derivative of general formula (2): HS—R 1 —Y, then in a second step at least one derivative of general formula (3): Z—R 2 , with R 1 and R 2 which represent independently of one another, linear or branched, unsaturated or saturated hydrocarbon groups such that the total number of carbon atoms of the R 1 and R 2 groups is comprised between 2 and 110, Y which represents an acid, alcohol or amine function, Z which represents an acid, alcohol, amine, anhydride or isocyanate function, it being understood that the reaction between the two functions Y and Z leads to the X function of general formula (1). The invention also relates to the use of the graft polymer GP as defined above in coatings, paints, thermoplastics, glues, lubricants, fuels, inks, cements, construction materials, rubbers or bitumens. The invention also relates to a bitumen/polymer composition comprising at least one bitumen and at least one graft polymer GP as defined above. Preferably, the bitumen/polymer composition comprises from 0.1 to 40% by mass of graft polymer GP, with respect to the mass of the bitumen/polymer composition, preferably from 0.5 to 30%, more preferentially from 1 to 20%, even more preferentially from 2 to 10%, even more preferentially from 3 to 5%.
[0019] The invention also relates to a process for the preparation of a bitumen/polymer composition in which at least one bitumen and at least one graft polymer GP as defined above, are mixed at a temperature comprised between 80° C. and 200° C., preferably between 100° C. and 180° C., more preferentially between 120° C. and 160° C., for a duration of 30 minutes to 4 hours, preferably 1 hour to 2 hours. The invention also relates to the use of the graft polymer GP as defined above in a bitumen/polymer composition for the thermoreversible cross-linking of said bitumen/polymer composition. The invention also relates to a bituminous mix comprising a bitumen/polymer composition as defined above and granules optionally comprising fines, sand, gravel. The invention also relates to the use of the graft polymer GP as defined above for reducing the coating, spreading and/or compacting temperatures during the production of a bituminous mix.
DETAILED DESCRIPTION
[0020] The invention relates to a graft polymer GP. By graft polymer GP is meant a polymer which comprises a main polymer chain P and side grafts G connected to this chain. The grafts G are connected directly to the main chain P of the polymer, in particular via a sulphur atom. The grafts G are grafted to the main polymer chain P, after polymerization of the latter, by chemical reaction, in one or more steps. The result is a covalent bond between the grafts G and the main chain P of the polymer. The graft polymers GP according to the invention are therefore obtained by polymerization, then grafting of the grafts G and not by polymerization of monomers already comprising grafts G.
[0021] The graft polymer GP according to the invention comprises a main polymer chain P and at least one side graft G connected to the main polymer chain P, the graft G having general formula (1):
[0000] —S—R 1 —X—R 2 (1)
[0000] in which:
the R 1 and R 2 groups represent independently of one another, linear or branched, unsaturated or saturated hydrocarbon groups. such that the total number of carbon atoms of the R 1 and R 2 groups is comprised between 2 and 110 and, the X group is chosen from the amide, amido-acid, ester, imide, urea or urethane functions. It should be noted that the graft G is connected to the main polymer chain P via the sulphur atom.
[0024] Preferably, the total number of carbon atoms in the R 1 and R 2 groups is comprised between 4 and 90, more preferentially between 8 and 70, even more preferentially between 12 and 50, even more preferentially between 16 and 40, even more preferentially between 18 and 30, even more preferentially between 20 and 24. The presence of these two R 1 and R 2 groups, via their significant number of carbons is indispensable for the crystallization, the reversible cross-linking of the graft polymer GP. Preferably, the number of carbon atoms of the R 1 group is comprised between 1 and 60, preferably between 2 and 50, more preferentially between 4 and 40, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12 and the number of carbon atoms of the R 2 group is comprised between 1 and 50, preferably between 2 and 40, more preferentially between 4 and 30, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12.
[0025] The R 1 and R 2 groups are preferably linear and saturated hydrocarbon groups, such that the total number of carbon atoms is comprised between 2 and 110, preferably between 4 and 90, more preferentially between 8 and 70, even more preferentially between 12 and 50, even more preferentially between 16 and 40, even more preferentially between 18 and 30, even more preferentially between 20 and 24. The R 1 and R 2 groups are then the C n H 2n and C m H 2m+1 groups respectively with n and m integers such that the sum n +m is comprised between 2 and 110, preferably between 4 and 90, more preferentially between 8 and 70, even more preferentially between 12 and 50, even more preferentially between 16 and 40, even more preferentially between 18 and 30, even more preferentially between 20 and 24. Preferably, n is comprised between 1 and 60, more preferentially between 2 and 50, even more preferentially between 4 and 40, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12 and m is comprised between 1 and 50, more preferentially between 2 and 40, even more preferentially between 4 and 30, even more preferentially between 6 and 25, even more preferentially between 8 and 20, even more preferentially between 9 and 15, even more preferentially between 10 and 12.
[0026] The graft polymer GP, in addition to the paraffinic parts defined by the R 1 and R 2 groups, also has a function denoted X. This additional function makes it possible to reinforce the interactions between polymer chains and therefore to reinforce the cross-linking of the graft polymer GP. This X function induces thermoreversible interactions of a polar nature and/or via hydrogen bonds.
[0027] The X function is chosen from the amide, amido-acid, ester, imide, urea and urethane functions. The amide, amido-acid, urea and urethane functions induce interactions via hydrogen bonds and polar interactions, while the imide and ester functions only induce polar interactions. According to a particular preferential embodiment, the X function is chosen from the amide, amido-acid, urea and urethane functions so as to induce interactions that are both polar and via hydrogen bonds.
[0028] According to the function chosen at the level of the X group, general formula (1) can be written in the following ways, with X an amide function in general formulae (1a) and (1b), X an amido-acid function in general formula (1c), X an ester function in general formulae (1d) and (1e), X an imide function in general formula (1f), X a urea function in general formula (1g) and X a urethane function in general formula (1h):
[0000]
[0029] When X is an amide function, it can be in two forms, either the carbonyl is linked to the R 1 group (Formula 1a), or it is linked to the R 2 group (Formula 1b). Similarly, when X is an ester function, either the carbonyl is linked to the R 1 group (Formula 1d), or it is linked to the R 2 group (Formula 1e). Preferably, the X group is an amide function as it can then induce two types of interactions, polar and via hydrogen bond.
[0030] The preferred graft polymer GP is such that n is equal to 14 and m is equal 18 and can be represented as: P—S—C 14 H 28 —CONH—C 18 H 37 , with P the main polymer chain connected via the sulphur atom with the graft which comprises an amide as X function, C 14 H 28 as the R 1 group and C 18 H 37 as the R 2 group. The graft polymer GP according to the invention comprises a main polymer chain P. This polymer chain P is obtained by polymerization of several monomers. In particular, this polymer chain P is obtained by polymerization of several monomers comprising double bonds. These double bonds are preferably conjugated double bonds.
[0031] Preferably, the polymer chain P is obtained by polymerization of conjugated diene units. The conjugated dienes which can be used according to the invention are chosen from those comprising 4 to 8 carbon atoms, such as 1-3 butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,2-hexadiene, chloroprene, carboxylated butadiene and/or carboxylated isoprene. Preferably, the polymer chain P is obtained by polymerization of butadiene units.
[0032] The polymer P can thus result from the homopolymerization only of diene units, preferably conjugated diene, preferably butadiene. In these polymers, along the polymer chain, several double bonds can be found resulting from the homopolymerization of the diene units, preferably conjugated diene, preferably butadiene. Such polymers are for example polybutadienes, polyisoprenes, polyisobutenes, polychloroprenes, but also butyl rubbers which are obtained by the concatenation of isobutene and isoprene copolymers. Copolymers or terpolymers obtained from diene units can also be found such as butadiene, isoprene, isobutene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, chloroprene units. In addition to these conjugated diene units, other units can be found.
[0033] Preferably, the polymer chain P is obtained by copolymerization of conjugated diene units and aromatic monovinyl hydrocarbon units. The aromatic monovinyl hydrocarbons which can be used according to the invention are chosen from styrene, o-methyl styrene, p-methyl styrene, p-tert-butylstyrene, 2,3 dimethyl-styrene, α-methyl styrene, vinyl naphthalene, vinyl toluene and/or vinyl xylene. Preferably, the polymer chain P is obtained by copolymerization of butadiene units and styrene units.
[0034] The polymers which can be used as starting material for forming the graft polymers GP according to the invention are therefore, preferably, chosen from the copolymers of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, linear or star, in diblock, triblock and/or multibranched form, optionally with or without a random hinge. Preferably the polymer which can be used as starting material for forming the graft polymers GP according to the invention is a diblock or triblock copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular a diblock or triblock copolymer of styrene and butadiene. The copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, advantageously has a content by weight of aromatic monovinyl hydrocarbon, in particular of styrene ranging from 5% to 50% by mass, with respect to the mass of copolymer, preferably from 10% to 40%, more preferentially from 15% to 35%, even more preferentially from 20% to 30%. The copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, advantageously has a content by weight of conjugated diene, in particular of butadiene ranging from 50% to 95% by mass, with respect to the mass of copolymer, preferably from 55% to 90%, more preferentially from 60% to 85%, even more preferentially from 65% to 80%.
[0035] These conjugated diene units include the units with 1-4 double bonds originating from the conjugated diene and the units with 1-2 double bonds originating from the conjugated diene. By units with 1-4 double bonds originating from the conjugated diene, is meant the units obtained via a 1,4 addition during polymerization of the conjugated diene. By units with 1-2 double bonds originating from the conjugated diene, is meant the units obtained via a 1,2 addition during polymerization of the conjugated diene. The result of this 1,2 addition is a so-called “pendant” vinylic double bond. During the preparation of the graft polymer GP, these are double bonds originating from the conjugated diene, in particular the butadiene units, which are reactive and available for grafting the grafts G. The grafting will take place on the units with 1-4 double bonds originating from the butadiene and the units with 1-2 double bonds originating from the butadiene, in particular on the units with 1-2 double bonds originating from the butadiene, which are a little more reactive.
[0036] Preferably, the copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, has a content in units with 1-2 double bonds originating from the conjugated diene, in particular originating from the butadiene, comprised between 5% and 70% by mass, with respect to the total mass of the conjugated diene units, in particular butadiene, preferably between 10% and 60%, more preferentially between 15% and 50%, even more preferentially between 18% and 40%, even more preferentially between 20% and 30%, even more preferentially between 22% and 25%. The copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, has a weight-average molecular weight M W comprised between 10,000 and 500,000 Daltons, preferably between 50,000 and 200,000, more preferentially between 80,000 and 150,000, even more preferentially between 100,000 and 130,000, even more preferentially between 110,000 and 120,000. The copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, has a number-average molecular weight M n comprised between 10,000 and 500,000 Daltons, preferably between 50,000 and 200,000, more preferentially between 80,000 and 150,000, even more preferentially between 100,000 and 130,000, even more preferentially between 110,000 and 120,000. The molecular masses of the copolymer are measured by gel permeation chromatography GPC with polystyrene standards according to standard ASTM D3536. The copolymer of aromatic monovinyl hydrocarbon and conjugated diene, in particular of styrene and butadiene, has a polydispersity index comprised between 1 and 4, preferably between 1.2 and 3, more preferably between 1.5 and 2, and even more preferably between 1.6 and 1.8.
[0037] The graft polymers GP according to the invention are prepared in two steps, allowing graft polymers GP with R 1 and R 2 groups comprising a large number of carbon atoms to be easily obtained. In a first step, a thiol derivative of formula (2): HS—R 1 —Y with R 1 having the definitions given above and Y a function chosen from the acid, alcohol or amine functions is grafted onto polymer P as defined above, in particular onto a copolymer of an aromatic monovinyl hydrocarbon and a conjugated diene, in particular onto a copolymer of styrene and butadiene.
[0038] This thiol derivative will react on the double bonds of polymer P, in particular on the double bonds originating from the conjugated diene units of polymer P, in particular on the double bonds originating from the butadiene units of polymer P. The thiol derivative will react on these double bonds via its thiol function, the other acid, alcohol or amine end being much less reactive.
[0039] This acid, alcohol or amine function will then be free on the polymer and available for a second reaction step. This first reaction step is therefore followed by a second reaction step in which the free acid, alcohol or amine functions react with derivatives of general formula (3): Z—R 2 with R 2 having the definitions given above and Z a function chosen from the acid, alcohol, amine, anhydride or isocyanate functions. The reaction between the Y and Z groups leads of course to the formation of the X function of general formula (1).
[0040] Thus, the graft polymer GP of general formula (1a) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —COOH with Y an acid function and a derivative of general formula (3) H 2 N—R 2 with Z an amine function, in order to form an X bond which is an amide bond. Of course these are irreversible covalent amide bonds. In order to promote the reaction between the acid Y function and the amine Z function, the acid Y function can be activated beforehand by compounds that are well known in organic chemistry.
[0041] Similarly, the graft polymer GP of general formula (1b) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —NH 2 with Y an amine function and a derivative of general formula (3) HOOC—R 2 with Z an acid function, in order to form a bond which is an irreversible covalent amide bond. In order to promote the reaction between the amine Y function and the acid Z function, the acid function can be activated beforehand by compounds that are well known in organic chemistry Thus, for example, the acid chloride ClCO—R 2 combined with the acid HOOC—R 2 can be reacted.
[0042] The graft polymer GP of general formula (1c) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —NH 2 with Y an amine function and a derivative of general formula (3) with Z a cyclic anhydride function in order to form an X bond which is an amido/acid bond:
[0000]
[0043] Starting from the graft polymer GP of general formula (1c), the graft polymer of general formula (1f) can be obtained. An internal cyclization reaction takes place under certain temperature conditions, in particular at high temperature. The graft polymer GP of general formula (1d) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —COOH with Y an acid function and a derivative of general formula (3) HO—R 2 with Z an alcohol function, in order to form an X bond which is an ester bond. The graft polymer GP of general formula (1e) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —OH with Y an alcohol function and a derivative of general formula (3) HOOC—R 2 with Z an acid function, in order to form an X bond which is an ester bond. In order to promote the formation of the ester bond, the acid chloride ClCO—R 2 combined with the acid HOOC—R 2 could also be reacted.
[0044] The graft polymer GP of general formula (1g) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —NH 2 with Y an amine function and a derivative of general formula (3) OCN—R 2 with Z an isocyanate function, in order to form an X bond which is a urea bond. The graft polymer GP of general formula (1h) is obtained by the reaction between a thiol derivative of formula (2) HS—R 1 —OH with Y an alcohol function and a derivative of general formula (3) OCN—R 2 with Z an isocyanate function, in order to form an X bond which is a urethane bond.
[0045] The first reaction step involves the polymer P as defined above and the thiol derivative of formula (2) as defined above. The polymer P and the thiol derivative of formula (2) are reacted at a temperature comprised between 20 and 200° C., preferably between 40 and 180° C., more preferentially between 60 and 140° C., even more preferentially between 80 and 120° C. The polymer P and the thiol derivative of formula (2) are reacted for a duration of from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours, more preferentially from 1 hour to 10 hours, even more preferentially from 2 hours to 4 hours. The mass ratio between the quantities of thiol derivative of formula (2) and of polymer P is comprised between 0.01 and 5, preferably between 0.05 and 4, more preferentially between 0.1 and 2, even more preferentially between 0.5 and 1.5, even more preferentially between 0.8 and 1. The molar ratio between the quantities of thiol derivative of formula (2) and of units originating from the conjugated diene of polymer P, preferably of 1-2 units originating from the conjugated diene of polymer P, is comprised between 0.01 and 5, preferably between 0.05 and 4, more preferentially between 0.1 and 2, even more preferentially between 0.5 and 1.5, even more preferentially between 0.8 and 1.
[0046] The reaction between the polymer P and the thiol derivative of formula (2) preferably takes place in a solvent such as toluene, but the mixing of these two reagents can also be carried out without organic solvent, the mixing of the two reagents taking place in polymer P heated to the temperatures mentioned above. In order to promote the reaction between polymer P and the thiol derivative of formula (2), a radical initiator can optionally be added. This radical initiator is preferably azobisisobutyronitrile (AIBN). By optimizing the temperature and duration conditions, the radical initiator can be omitted.
[0047] An inert atmosphere can also optionally be used for this first reaction step, such as an inert atmosphere of nitrogen or argon. The first reaction step can be carried out with or without mechanical stirring. The grafting of the thiol derivative of formula (2) can be improved by using any type of mechanical stirring.
[0048] The product of the reaction between polymer P and the thiol derivative of formula (2) can optionally be purified by precipitation from a solvent such as methanol. An anti-oxidant agent, such as 2,6-di-tert-butyl-4-methylphenol can optionally be added to the product of the reaction between polymer P and the thiol derivative of formula (2). This anti-oxidant agent can be added with solvent such as toluene, which solvent is then evaporated off.
[0049] During this first grafting reaction step, chain cleavage and/or chain branching can occur at the level of the polymer chain. This can result in irreversible covalent-type coupling, branching, partial cross-linking of the polymer chains, which would add to the reversible thermal cross-linking due to the R 1 , R 2 and/or X groups. This phenomenon is of minor importance, as the reversible thermal cross-linking is predominant.
[0050] The second reaction step involves the product of the reaction between polymer P and the derivative of formula (2), i.e. the reaction product of the first step, and a derivative of formula (3) as defined above. The product of the reaction of the first step and the derivative of formula (3) are reacted at a temperature comprised between 0 and 200° C., preferably between 10 and 180° C., more preferentially between 20 and 140° C., even more preferentially between 40 and 120° C., even more preferentially between 80 and 100° C. The product of the reaction of the first step and the derivative of formula (3) are reacted for a duration of from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours, more preferentially from 1 hour to 10 hours, even more preferentially from 2 hours to 4 hours. The reaction between the product of the reaction of the first step and the derivative of formula (3) preferably takes place in a solvent such as toluene.
[0051] In order to synthesize the graft polymer GP of general formula (1a), to activate the acid functions present on the reaction product of the first step, an activator is preferably added such as a mixture of N-hydroxysuccinimide and dicyclohexylcarbodiimide, any other standard activator used in peptide chemistry can be used. It is only after this activation, that the derivative of formula (3) is added in order to form the amide bond. An inert atmosphere can also optionally be used for this second reaction step, such as an inert atmosphere of nitrogen, or of argon.
[0052] The second reaction step can be carried out with or without mechanical stirring. The grafting of the derivative of formula (3) can be improved by using any type of mechanical stirring. The product of the second reaction step can optionally be purified by precipitation from a solvent such as methanol.
[0053] An anti-oxidant agent, such as 2,6-di-tert-butyl-4-methylphenol can optionally be added to the product of the second reaction step. This anti-oxidant agent can be added with solvent such as toluene, which solvent is then evaporated off.
[0054] The graft polymers GP according to the invention are of use in many fields, and in particular in additives for controlling and improving the viscosity and fluidity of formulations, additives for modifying the gel-like appearance of organic solutions, rheological and/or adhesion additives for coatings on different types of surface, additives to vary the fluidity of paints, additives in the formulation of non-modified bitumens and modified bitumens, additives in the formulation of cements or construction materials, additives in the formulation of rubber, anticorrosion additives, additives in the fields of textile, fabric and paper, additives for impact modification in polymers, additives for glues, adhesive formulations, additives for lubricants, additives in cosmetic formulations, additives in inks, additives in photographic materials, additives for materials for printed circuits. Therefore a subject of the invention is also bitumen/polymer compositions comprising the graft polymers GP according to the invention. The bitumen/polymer compositions comprise from 0.1 to 40% by mass of graft polymers GP, with respect to the mass of the bitumen/polymer compositions, preferably from 0.5 to 30%, more preferentially from 1 to 20%, even more preferentially from 2 to 10%, even more preferentially from 3 to 5%.
[0055] The bitumen which can be used according to the invention can be a bitumen of different origins. The bitumen which can be used according to the invention can be chosen from the bitumens of natural origin, such as those contained in deposits of natural bitumen, natural asphalt or bituminous sands. The bitumen which can be used according to the invention can also be a bitumen or a mixture of bitumens resulting from the refining of crude oil such as bitumens resulting from direct or reduced pressure distillation or also blown or semi-blown bitumens, propane or pentane de-asphalting residues, visbreaking residues, these different cuts being alone or in a mixture. The bitumens used can also be bitumens fluxed by the addition of volatile solvents, fluxes originating from oil, carbochemical fluxes and/or fluxes of vegetable origin. It is also possible to use synthetic bitumens also called clear, pigmentable or colourable bitumens. The bitumen can be a bitumen of naphthenic or paraffinic origin, or a mixture of these two bitumens. The bitumens of paraffinic origin are preferred.
[0056] The other polymers optionally present in the bitumen/polymer compositions are polymers which can be used in a standard fashion in the field of bitumen/polymer compositions, such as for example the triblock copolymers of an aromatic monovinyl hydrocarbon block and a conjugated diene block such as the styrene/butadiene/styrene SBS triblock copolymers, the multibranched copolymers of aromatic monovinyl hydrocarbon blocks and a conjugated diene block, such as the styrene/butadiene (SB) n X multibranched block copolymers, copolymers of an aromatic monovinyl hydrocarbon block and a “random” conjugated diene block such as the styrene/butadiene rubber SBR copolymers, polybutadienes, polyisoprenes, powdered rubbers originating from tyre recycling, butyl rubbers, polyacrylates, polymethacrylates, polychloroprenes, polynorbornenes, polybutenes, polyisobutenes, polyolefins such as polyethylenes, polypropylenes, copolymers of ethylene and vinyl acetate, copolymers of ethylene and methyl acrylate, copolymers of ethylene and butyl acrylate, copolymers of ethylene and maleic anhydride, copolymers of ethylene and glycidyl methacrylate, copolymers of ethylene and glycidyl acrylate, copolymers of ethylene and propylene, ethylene/propylene/diene (EPDM) terpolymers, acrylonitrile/butadiene/styrene (ABS) terpolymers, ethylene/alkyl acrylate or methacrylate/glycidyl acrylate or methacrylate terpolymers and in particular ethylene/methyl acrylate/glycidyl methacrylate terpolymers and ethylene/alkyl acrylate or alkyl methacrylate/maleic anhydride terpolymers and in particular ethylene/butyl acrylate/maleic anhydride terpolymers.
[0057] In addition to the bitumen and graft polymers, other optional ingredients commonly used in bitumens can be present. These ingredients can be fluxes such oils based on animal and/or vegetable fatty materials or on hydrocarbon oils of petroleum origin. The oils of animal and/or vegetable origin can be in the form of free fatty acids, triglycerides, diglycerides, monoglycerides, in esterified form, for example in the form of methyl ester.
[0058] These ingredients can be waxes of animal, vegetable or hydrocarbon origin, in particular long-chain hydrocarbon waxes, for example polyethylene waxes or Fischer-Tropsch waxes. The polyethylene waxes or Fischer-Tropsch waxes can optionally be oxidized. The fatty amide waxes such as ethylene bis-stearamide can also be added.
[0059] These ingredients can be resins of vegetable origin such as colophanes. These ingredients can be acids such as polyphosphoric acid or diacids, in particular fatty diacids. These ingredients can be adhesiveness dopes and/or surfactants. They are chosen from the derivatives of alkylamines, derivatives of alkyl-polyamines, derivatives of alkylamidopolyamines, derivatives of alkyl amidopolyamines and derivatives of quaternary ammonium salts, alone or in a mixture. The most used are tallow propylene-diamines, tallow amido-amines, quaternary ammoniums obtained by quaternization of tallow propylene-diamines, tallow propylene-polyamines.
[0060] The bitumen/polymer compositions are prepared by mixing the graft polymer GP and bitumen. Mixing takes place at a temperature comprised between 80° C. and 200° C., preferably between 100° C. and 180° C., more preferentially between 120° C. and 160° C., for a duration of 30 minutes to 4 hours, preferably from 1 hour to 2 hours, optionally under stirring. The graft polymers GP obtained according to the method described above can be used in the field of bitumens, in road making and/or in industry. The graft polymers GP make it possible to formulate bituminous compositions and in particular bitumen/polymer compositions that are cross-linked, preferably thermoreversibly.
[0061] The cross-linking of the bitumen/polymer compositions comprising said graft polymers can be demonstrated by subjecting these bitumen/polymer compositions to tensile testing according to standard NF EN 13587. The cross-linked bitumen/polymer compositions have higher tensile strength than the non-cross-linked bitumen/polymer compositions. A higher tensile strength is reflected in a high elongation at break or maximum elongation (ε max in %), a high breaking stress or stress at maximum elongation (σε max in MPa), a high conventional energy at 400% (E 400% in J/cm 2 ) and/or a high total energy (E total in J).
[0062] The cross-linked bitumen/polymer compositions have a maximum elongation, according to standard NF EN 13587, greater than or equal to 400%, preferably greater than or equal to 500%, more preferentially greater than or equal to 600%, and even more preferentially greater than or equal to 700%. The cross-linked bitumen/polymer compositions have a stress at maximum elongation, according to standard NF EN 13587, greater than or equal to 0.2 MPa, preferably greater than or equal to 0.4 MPa, more preferentially greater than or equal to 0.6 MPa, and even more preferentially greater than or equal to 1 MPa. The cross-linked bitumen/polymer compositions have a conventional energy at 400%, according to standard NF EN 13587, greater than or equal to 3 J/cm 2 , preferably greater than or equal to 5 J/cm 2 , more preferentially greater than or equal to 10 J/cm 2 , and even more preferentially greater than or equal to 15 J/cm 2 . The cross-linked bitumen/polymer compositions have a total energy, according to standard NF EN 13587, greater than or equal to 1 J, preferably greater than or equal to 2 J, more preferentially greater than or equal to 4 J, and even more preferentially greater than or equal to 5 J.
[0063] The bitumen/polymer compositions comprising the graft polymers can be intended for the manufacture of mixes, surface coatings (road making applications) or membranes, sealing coats (industrial applications). The bituminous mix comprises from 1 to 10% by mass of bitumen/polymer composition, with respect to the total weight of the mix, preferably from 4 to 8 by mass. The use of graft polymers GP in bitumen/polymer compositions, during manufacture of a mix, makes it possible to reduce the manufacturing or coating, spreading and compacting temperatures with respect to the temperatures normally used. In fact due to thermoreversible cross-linking, the bitumen/polymer compositions have both reduced viscosities in the ranges of manufacturing temperatures of a mix (implementation temperatures) due to the disappearance of the crystalline domains due to the R 1 and R 2 groups and interactions that are polar or via hydrogen bonds due to the X function of the polymer GP and at the same time the return of these crystalline domains and these interactions when the temperatures decrease and, as a result, good mechanical properties at the temperatures of use (consistency, elasticity for example).
EXAMPLES
Example 1
Preparation of a polymer P—S—C 14 H 28 —CONH—C 18 H 37 —6.5% molar
[0064] The graft polymer GP of type P—S—R 1 —X—R 2 according to the invention is prepared, having the general formula P—S—C 14 H 28 —CONH—C 18 H 37 , with P the polymer chain, R 1 representing the C 14 H 28 group, R 2 representing the C 18 H 37 group and X representing an amide function. This graft polymer is prepared from:
styrene/butadiene/styrene SBS triblock copolymer having a mass M w equal to 122,000 g.mol −1 , a mass M n equal to 115,000 g.mol −1 , a polydispersity index equal to 1.06, a quantity by mass of styrene of 30.4%, a quantity by mass of 1,2-butadiene of 26.6%, a quantity by mass of 1,4-butadiene of 43%, with respect to the mass of the copolymer. thiol derivative/acid of formula (2): HS—C 14 H 28 —COOH, amine derivative of formula (3): H 2 N—C 18 H 37 .
[0068] Preparation of the Graft Polymer GP According to the Invention
[0069] The graft polymer GP is synthesized in two steps. The first step corresponds to a radical addition of an alkanethiol comprising a carboxylic acid function (mercaptoalkanoic acid). The second step corresponds to the amidification of the acid functions with an amine derivative.
[0070] First Step
[0071] 110 ml of toluene and 4 g of SBS polymer described above are introduced into a reaction vessel maintained under nitrogen atmosphere and at ambient temperature. Then 2.6 g of thiol derivative/acid described above is introduced into the reaction vessel. The mixture is brought to 90° C. and 15 mg of AIBN (azobisisobutyronitrile) solubilized in 1 ml of degassed toluene is added. After 3 hours and 30 minutes at 90° C., under an inert atmosphere, the solution is cooled down to ambient temperature. The polymer is precipitated three times from methanol. The polymer is then solubilized in toluene and 2,6-di-tert-butyl-4-methylphenol is added (1 mg per 1 g of polymer). The solution is poured into a Teflon mould and the toluene is evaporated off. The polymer films are dried under vacuum for 24 hours and stored at 4° C.
[0072] The molar % of grafted thiol derivative/acid, with respect to the butadiene units is 12%. This molar % of grafted thiol derivative/acid is the number of moles of grafted thiol derivative/acid with respect to the number of moles of the butadiene units present on the starting polymer chain. The molar % of grafted thiol derivative/acid, with respect to the butadiene units and to the styrene units is 10%. This molar % of grafted thiol derivative/acid is the number of moles of grafted thiol derivative/acid with respect to the number of moles of the butadiene units and of the styrene units present in the starting polymer chain.
[0073] The % by mass of grafted thiol derivative/acid is 32%. This % by mass of grafted thiol derivative/acid is the mass of grafted thiol derivative/acid with respect to the total mass of graft polymer obtained in the first reaction step. The grafting yield of the first reaction step is 65%. By grafting yield is meant the quantity of grafted thiol derivative/acid with respect to the quantity of thiol derivative/acid introduced in this first step.
[0074] Second Step
[0075] 3 g of the polymer obtained during the first reaction step is solubilized in 90 ml of toluene at ambient temperature and under stirring. Then 0.8 g of N-hydroxysuccinimide is introduced. 0.46 g of dicyclohexylcarbodiimide is solubilized in 1 ml of toluene, which is then added dropwise to the reaction medium. The mixture is stirred at ambient temperature for 5 hours. Then 1.06 g of the amine derivative described above, previously solubilized in 1 ml of toluene, is introduced and left to react for 10 hours. The mixture is precipitated twice from methanol. The graft polymer GP obtained is then solubilized in toluene and 2,6-di-tert-butyl-4-methylphenol (1 mg per 1 g of polymer) is added. The solution is poured into a Teflon mould and the toluene is evaporated off. The polymer films are dried under vacuum for 24 hours and stored at 4° C.
[0076] The molar % of grafted thiol derivative/amide is 8.1% with respect to the butadiene units. This molar % of grafted thiol derivative/amide is the number of moles of grafted thiol derivative/amide with respect to the number of moles of the butadiene units present on the starting polymer chain. The molar % of grafted thiol derivative/amide, with respect to the butadiene units and the styrene units is 6.5%. This molar % of grafted thiol derivative/amide is the quantity of grafted thiol derivative/amide with respect to the number of moles of the butadiene units and of the styrene units present in the starting polymer chain.
[0077] The % by mass of grafted thiol derivative/amide is 32%. This % by mass of grafted thiol derivative/amide is the mass of grafted thiol derivative/amide with respect to the total mass of graft polymer obtained in the second reaction step. The grafting yield of the second reaction step is 65%. By grafting yield is meant the quantity of grafted amine derivative with respect to the quantity of amine derivative introduced in this second step.
[0078] Properties of the Graft Polymer GP
[0079] The viscoelastic properties of the graft polymer GP, and in particular the formation of a gel in a 10% by mass solution in toluene, were investigated by measuring the moduli G′ (storage modulus) and G″ (loss modulus) under cooling and heating (between 25° C. and −8° C. at 0.5° C./min under a frequency of 0.9 rad.s −1 and a deformation of 1%).
[0080] The results are shown in Table I below.
[0000]
TABLE I
Temperature
G′ (Pa)
G″ (Pa)
G′ (Pa)
G″ (Pa)
(° C.)
Cooling
Cooling
Heating
Heating
−8
54000
1240
54000
1240
−6
41500
990
52900
1180
−4
35400
830
50100
1100
−2
28600
660
48400
1020
0
21500
470
42800
840
2
14000
300
41100
810
4
6640
160
33600
630
7
590
20
26700
470
10
4
1
19000
310
11
0.3
0.4
18700
290
13
—
—
11100
170
16
—
—
4290
60
19
—
—
634
11
22
—
—
1.5
0.5
25
—
—
—
—
[0081] At ambient temperature (20-25° C.), the solution of polymer GP is very liquid. During cooling, starting from 10° C., the values of the moduli G′ and G″ increase very significantly with the values of modulus G′ much greater than those of modulus G″, which demonstrates the formation of a gel with a high elastic component. The graft polymer GP is therefore capable of forming a gel in solution. The gelling takes place around 10° C. during cooling. This gel disappears when heating is applied around 22° C., which demonstrates the thermoreversibility of the system.
[0082] The viscosities of the graft polymer GP (10% by mass in toluene) are also measured. Flow measurements cannot be carried out as a function of temperature because the gel formed by the graft polymer GP is so strong that there is a risk of fracturing it when putting it under stress in this way. For this reason, only oscillation measurements (measurements of moduli G′ and G″) are carried out as a function of temperature. These measurements give access to a complex viscosity η* (η*=G*/ω with G* the complex modulus).
[0083] The results are shown in Table II below.
[0000]
TABLE II
Temperature (° C.)
Viscosity (Pa · s)
25
0.098
20
0.415
15
0.752
10
501
5
1290
0
2200
−5
3140
−8
3950
−10
—
[0084] A sudden increase in the viscosity is noted starting from 10° C. These viscosity measurements are well correlated with the measurements of moduli G′ and G″ which demonstrate that the graft polymer GP is capable of forming a thermoreversible gel in toluene around 10° C.
Example 2
Preparation of a polymer P—S—C 14 H 28 —CONH—C 18 H 37 —1.5% molar
[0085] A graft polymer GP of type P—S—C 14 H 28 —CONH—C 18 H 37 according to the invention is synthesized according to an operating procedure identical to Example 1, with the exception of the quantities of the thiol derivative/acid of formula (2) and of the amine derivative of formula (3) as well as the quantities of AIBN, N-hydroxysuccinimide and dicyclohexylcarbodiimide adjusted so as to obtain a molar % of the grafted thiol derivative/amide with respect to the butadiene units and to the styrene units of 1.5%.
[0086] First Step
[0087] 0.64 g of the thiol derivative/acid of formula (2) and 3.85 mg of AIBN are used, the quantities of the other components remaining identical to Example 1. Then a molar % of grafted thiol derivative/acid is obtained, which with respect to the butadiene units is 2% and a molar % of grafted thiol derivative/acid, which with respect to the butadiene units and to the styrene units is 1.5%. The % by mass of grafted thiol derivative/acid is 6% and the grafting yield of the first reaction step is 40%.
[0088] Second Step
[0089] 83 mg of N-hydroxysuccinimide, 0.15 g of dicyclohexylcarbodiimide and 0.19 g of amine derivative of formula (3) are used, the quantities of the other components remaining identical to Example 1. The molar % of grafted thiol derivative/amide, with respect to the butadiene units is 2% and the molar % of grafted thiol derivative/amide, with respect to the butadiene units and to the styrene units is 1.5%. The % by mass of grafted thiol derivative/amide is 11%. The grafting yield of the second reaction step is 100%.
Example 3
Preparation of a Bitumen/Polymer Composition
[0090] Bitumen
[0091] The bitumen is a bitumen of penetrability 50 1/10 mm, the characteristics of which correspond to the standard NF EN 1426.
[0092] Bitumen/Polymer Composition C According to the Invention
[0093] A bitumen/polymer composition is prepared from the bitumen described above and the graft polymer GP of formula P—S—C 14 H 28 —CONH—C 18 H 37 of Example 2 at a concentration of 5% by mass. The bitumen described above is introduced into a reaction vessel maintained at 180° C. and equipped with a mechanical stirring system. The bitumen is heated at 180° C. and stirred for approximately 60 minutes. Then the graft polymer GP of formula P—S—C 14 H 28 —CONH—C 18 H 37 is added at 5% by mass. Mixing is carried out for a duration of 4 hours under stirring.
[0094] Control Bitumen/Polymer Composition T 1
[0095] A non-cross-linked control bitumen/polymer composition is prepared as follows: The bitumen described above is placed in a reaction vessel. The bitumen is heated at 180° C. and stirred for approximately 60 minutes. Then 5% by mass of the styrene/butadiene/styrene SBS triblock copolymer described in Example 1 is added. The mixture is stirred and heated at 180° C. for approximately 4 hours.
[0096] Control Bitumen/Polymer Composition T 2
[0097] An irreversibly cross-linked control bitumen/polymer composition is also prepared as follows: A control bitumen/polymer composition T 1 is prepared as described above, to which 0.13% by mass of sulphur is added. The mixture thus obtained is stirred and heated at 180° C. for 1 h30.
[0098] The following table shows the physical characteristics of compositions C, T 1 and T 2 .
[0099] Results
[0000]
C
T 1
T 2
Penetrability (0.1 mm) (1)
36
52
36
RBT (° C.) (2)
62.6
56.2
64.2
Viscosity at 80° C.
80.85
37.00
65.00
Viscosity at 100° C.
12.26
14.36
17.49
Viscosity at 120° C.
4.01
3.91
4.80
Viscosity at 140° C.
1.19
1.30
1.61
Viscosity at 160° C.
0.46
0.55
0.69
Viscosity at 180° C.
0.23
0.28
0.34
Viscosity at 200° C.
0.14
0.17
0.20
Max. elongation at 5° C. (%) (3)
700
95
700
Stress (daN/cm 2 ) (3)
16.34
/
12.01
(1) According to standard EN 1426
(2) Ring and Ball Temperature, according to standard EN1427
(3) Tensile test at 5° C., according to standard NF T 66-038, with a stretching rate of 100 mm/min.
[0100] The results of this table demonstrate that the bitumen/olymer composition according to the invention is less viscous starting from 100° C. than the non-cross-linked bitumen/polymer composition T 1 and composition T 2 cross-linked with sulphur. Moreover, it is noted that at the temperatures of use, the elastic and elongation properties of the bitumen/polymer composition according to the invention are improved with respect to a non-cross-linked bitumen/polymer composition T 1 and comparable to those of the bitumen/polymer composition T 2 cross-linked with sulphur. A thermoreversible effect is therefore observed. | A graft polymer PG includes a polymer backbone P and at least one side graft G linked to the polymer backbone, the graft G having the general formula (1): in which R 1 and R 2 represent, separately from one another, straight or branched, unsaturated or saturated hydrocarbon groups, such that the total number of carbon atoms in groups R 1 and R 2 is between 2 and 110; X represents an amide, amino-acid, urea or urethane function, the graft G being linked to the polymer backbone P via the sulphur atom. The graft polymer PG is a polymer that allows thermoreversible cross-linking and can be used in many fields such as coatings, paints, thermoplastics, adhesives, lubricants, fuels, inks, cements, construction materials, rubbers and bitumens. The graft polymer PG can be used in particular for thermoreversibly cross-linking bitumen/polymer compositions and thus for reducing coating, spreading and/or compaction temperatures during the production of bituminous coated materials. | 2 |
REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Patent Application No. 60/533,147, filed Dec. 31, 2003, whose disclosure is hereby incorporated by reference in its entirety into the present disclosure.
FIELD OF THE INVENTION
The present invention is directed to a passive optical sensor and more particularly to a passive optical sensor which operates by causing a wavelength-dependent change in the optical characteristics of a carbon nanotube material.
DESCRIPTION OF RELATED ART
Fiber optic networks are being developed by the US Air Force and the aerospace industry to control future aircraft in what has been termed the “Fly-by-Fiber” initiative. Essential to the operation of this passive fiber optic network are sensors that measure a variety of parameters required for flight control and other aircraft needs. These sensors must operate in a totally passive mode, where electrical power is not needed to be brought to the sensors. Furthermore, the sensors need to be compatible with the characteristics of wavelength division multiplexing, WDM, fiber optic networks. Lastly, but very importantly, the sensors need to be able to withstand very high levels of electromagnetic interference, EMI. These are a very challenging set of requirements that no other technology has been able to demonstrate a potential to meet.
The needs with respect to operability with WDM fiber optic networks are compounded by the additional requirements of operation in the harsh aircraft environment, field maintenance and service life. Sensors have to make a measurement of the physical parameter that they are intended to measure and place information regarding the value of that measurement onto the optical fiber in a manner that meets the WDM fiber optic network requirements just stated. In particular, information encoding methods that send information regarding the value that is being measured in the form of amplitude modulation of the light signal are not desired. This is mostly due to the fact that optical interconnections demonstrate dramatically variable amplitude losses. This gives rise to the need to recalibrate the system every time an optical connection is remade or when shock, vibration or strain changes the optical loss of a fiber optic connector. Such a recalibration requirement is unworkable in practice and is therefore unacceptable.
Simple sensors that work in a way that is light amplitude dependent would output an amount of light that is proportional to the value of the parameter being sensed. This light amplitude would be transmitted through the optical fiber and a detector would measure the light amplitude to obtain a signal that is representative of the parameter that was measured. This general technique has the problem that the light path through the optical network has to remain steady in that light losses cannot vary over time or through any other effects. This condition is almost never met in practical fiber optic networks, especially networks that operate on aircraft. For instance, typical fiber optic connectors can exhibit anywhere from a small fraction of a decibel loss to several decibels of loss, depending on the particular alignment, the buildup of dirt or grease and numerous other factors. This makes sensors that utilize light amplitude as their means of transmitting information not acceptable for this application.
In a different field of endeavor, carbon nanotubes are comprised of pure carbon that is in the form of a two dimensional sheet, termed graphene, that is rolled back upon itself to form a tubule or cylinder object with hemispherical end caps. The tubes are from about 0.3 nanometers to several nanometers in diameter, for the single walled variety, and up to approximately one millimeter in length. Tubes formed within tubes, termed multi-walled nanotubes, are also formed, and can have much greater diameters.
Carbon, the sixth element in the periodic table, is unique in nature and has many chemical forms and is the basis of life on earth. It forms covalent chemical bonds with itself and other elements that form into molecules, assemblages of atoms that have a definite size and shape. Most other elements in electronic or optical devices, such as silicon and metals, form ionic bonds that organize themselves into crystal structures that may grow to arbitrary size and shape, as they have no definite boundary as does a molecular structure.
The covalent bond that carbon forms in carbon nanotubes is what chemists call a hybrid orbital of the s orbital of one carbon atom and a p 2 orbital of another carbon atom, resulting in an sp 2 hybrid bond. This bond combines two carbon atoms at a 120 degree angle from one another and is flat, or two dimensional. Alternatively, carbon may combine with other carbon atoms in a sp 3 hybrid bond that is a three dimensional tetrahedral structure. Diamond is an example of this structure. Interestingly, the sp 2 hybrid bond in carbon nanotubes is stronger than the sp 3 hybrid bond of diamond.
When a two dimensional sheet of carbon atoms held together in the sp 2 hybrid bond form a tube, the normally flat bonds are stressed to accommodate the curvature of the tube. In nanotube literature, the nanotube is characterized in terms of its basis vectors, normally referred to by the indexes n, m that denote how far along each basis vector must be traveled to come back to the same point on the tube. Examples are 8,0 or 6,2 or 5,3 nanotubes. Although a complete discussion of the electronic band structure of nanotubes is rather complex, a simple intuitive view can be obtained by noting that the various amount of strain on the sp 2 hybrid bond produced by nanotubes of varying n,m indexes causes among other things the gap between the valence band and the conduction band, termed the bandgap, to vary. Reference 6 below gives a thorough review of carbon nanotube band structure. When n=m, the bandgap vanishes and the nanotube is a metal. When n−m is evenly divisible by three, the bandgap is finite, but smaller than room temperature thermal energy of about 25 milli-electron volts. Therefore electrons can easily hop across the band gap due to thermal energies and these nanotubes are termed either semi-metals or simply metallic as well. All other nanotubes are semiconductors; their band gaps vary considerably, and have been found to be roughly proportional to the inverse of the nanotube diameter.
The actual population of allowed levels by electrons within a nanotube is described by the density of states, or DOS, equation. The density of states exhibits large spikes termed van Hove singularities. Optical transitions can take place between a van Hove singularity in the valence band and a van Hove singularity in the conduction band. In the case of a transition between the first van Hove singularity in the valence band to the first van Hove singularity in the conduction band, the optical transition is termed a V 1 to C 1 , or sometimes an E 11 or sometimes an S 11 transition, depending on the author.
However, the properties of carbon nanotubes noted above have not yet been exploited in a passive optical sensor which can meet the above-noted requirements.
SUMMARY OF THE INVENTION
It will be seen that a need exists in the art to meet the requirements noted above for a passive optical sensor.
It is therefore an object of the invention to incorporate carbon nanotubes into a sensor so that the encoded information does not depend on the amplitude of the light.
It is another object of the invention to provide sensors which can provide completely passive optical operation of the entire network outside of a hardened central box where the computer processors, light sources and intelligent logic resides.
It is another object of the invention to provide sensors that need only enough light to be detected and yield an acceptable signal to noise ratio, but the specific light amplitude may vary considerably as long as this basic requirement is met and the information contained in the encoding technique will still give the correct measurement result.
To achieve the above and other objects, the present invention is directed to passive optical sensors which use carbon nanotubes to meet the requirements of “Fly-by-Fiber” WDM fiber optical networks as given above. These sensors are quite small and operate with no external supply of electrical power, and this is what is meant by a passive sensors. These sensors operate by means of light and thus are termed optical sensors, but they are intended to measure any physical parameter needed, such as voltage, current, magnetic field, temperature, pressure, oxygen or the presence of certain chemical or biological agents.
There are two related concepts that will be developed. Each concept provides the ability to transmit the information pertaining to the value of the parameter being measured without relying on the amplitude of the light signal going through the optical fiber.
The present invention senses a physical quantity by sensing a change in a wavelength-dependent optical characteristic (e.g., absorption or fluorescence) of carbon nanotubes caused by that physical quantity. The first technique utilizes a technique based on changing the exact wavelength at which a nanotube absorbs light as the technique to encode the information that is being sensed. The second technique compares light at two wavelengths (e.g., either absorption at those wavelengths or excitation and fluorescence).
With regard to the first technique mentioned above, it has been reviewed in the research literature that carbon nanotubes exhibit a phemonenon where their bandgap changes upon physical distortion, such as twisting or elongation or radial compression [References 7 through 10 ]. This effect is related to further stressing of the sp 2 hybrid bonds as described above, in a simplified view of the effect of the physical distortion on the nanotube band structure. It has been shown that, in the case of a compressive radial distortion that has the effect of flattening the nanotube, a radial compression of about 22% for certain nanotubes causes the bandgap to completely close. The nanotube has then undergone a semiconductor to metallic transition. It was then shown that further distortion opened up the bandgap again, making for a metallic to semiconducting transition.
When a nanotube demonstrates an optical transition between, for instance, the first van Hove singularity in the valence band to the first van Hove singularity in the conduction band, this manifests itself as a narrow bandwidth absorption resonance in the optical transmission spectrum of the nanotube. The present inventor was the first to recognize, to his knowledge, that changing the nanotube bandgap also changes the distance between these two van Hove singularities and consequently changes the wavelength of the optical absorption of the nanotube. When the bandgap changes, so does the distance between the two van Hove singularities and the wavelength at which the optical absorption resonance changes accordingly. The only reference that marginally suggests this effect is Reference 5 , where the optical spectra of nanotubes in micelles, or floating in surfactant solution was different from the optical spectra of nanotubes deposited onto a flat substrate. It was theorized by Axel Hagen and Tobias Hertel that the stresses on the nanotube were caused by imperfections in the substrate surface as the nanotube cling to the surface through van der Walls forces. This caused distortions in the nanotubes that may have altered the bandgap, but they did not actually say this in their research report [Reference 5 ]. Axel Hagen and Tobias Hertel estimated that this caused a blue shift in the nanotube spectra of about 65 nanometers and this seemed to be consistent with the published values of nanotube compressive modulus and the amount of strain that could reasonably be estimated from the surface imperfections.
The second technique is based on selective modulation of nanotube optical absorption. The Fermi level is the level to which electrons actually populate the allowed states in any given nanotube [Reference 6 ]. The Fermi level typically sits somewhere near the center of the bandgap in semiconducting nanotubes. Electrons can be either supplied to or taken away from the population of electrons in a nanotube by action of electric fields that are very near the nanotubes surface [References 2 through 4 ]. This has the effect of modulating the Fermi level in the nanotube. The phenomenon for this mechanism is called charge transfer doping and the electric field acts through what has been termed the “quantum capacitance” or sometimes the “chemical capacitance”. This is another remarkable feature of carbon nanotubes. Electric fields acting very near the surface have a dramatic effect on nanotubes, so much so that single molecule sensors have been proposed based on this phenomenon. On the other hand externally generated electric fields have almost no effect on nanotubes [References 1 - 2 ] up to hundreds of millions of volts per meter. This gives the nanotubes the essential property of immunity from large amounts of EMI, which is a critical need for the Air Force.
In order for an optical absorption transition to take place an electron has to be present on the ground or relaxed state in order to take in the energy of the optical photon and be elevated into the higher energy state. If the Fermi level is slightly lowered so that there are fewer electrons available in this ground state, then the strength of the optical absorption will be lowered. One such way to create an electric field near the surface of a nanotube is to use free charges in a solution, such as an electrolyte [References 3 and 4 ]. In this situation the free charge may be driven to the nanotube surface by an external electric field [Reference 3 ] to modify the Fermi level. Another means is to vary the strength of the electrolyte by using electrolytes of differing ph values [Reference 4 ].
A variation of the embodiment uses fluorescence of the nanotubes rather than absorption characteristics. That variation uses the fact that carbon nanotubes have been found to fluoresce brightly [Reference 11 ] undergoing a process termed direct bandgap fluorescence. In this process light is absorbed at the S 22 transition wavelength and the nanotube sheds the absorbed light energy by emitting a light photon at the S 11 wavelength. Since transitions between van Hove singularities are involved similar to the discussions above, this process is termed direct bandgap fluorescence and can be very efficient. More typically in conventional fluorescence, emission follows a complicated path to de-excitation that leads to the emission of a fluorescence photon with some degree of probability, and is therefore much less efficient. Since the ratio between light at the S 22 and S 11 wavelengths is measured, the variation is also amplitude independent.
It must be emphasized that in all of the sensors concepts to be disclosed in this patent disclosure based on carbon nanotubes, that carbon nanotubes have been found to be almost totally immune to even extremely high levels of electromagnetic interference, EMI, which is a major requirement of these sensors [References 1 and 2 ]. Carbon nanotubes, even the semiconducting types that are being employed in this disclosure, demonstrate the remarkable property that they completely shunt external sources of electric field. This has been found to be true for external sources of electric field up to hundreds and perhaps even thousands of millions of volts per meter. The Air Force has an EMI immunity requirement that devices need to withstand fields on the order of several million volts per meter, so nanotubes surpass this requirement by many orders of magnitude. This is a very important advantage for carbon nanotubes in this application, as no other technology is known that has this remarkable and critical property.
Throughout the present disclosure, the prior art is discussed with reference to the following references:
Reference 1 : L. Lou, P. Nordlander and R. E. Smalley “Fullerene nanotubes in electric fields”, Physical Review B , Volume 52, Number 3, 15 Jul. 1995, pages 1429-1432
Reference 2 : Alain Rochefort, Massimiliano Di Ventra, and Phadeon Avouris “Switching behavior of semiconducting carbon nanotubes under an external electric field”, Applied Physics Letters , Volume 78, Number 17, 23 Apr. 2001, pages 2521-2523
Reference 3 : Sami Rosenblatt, Yuval Yaish, Jiwoong Park, Jeff Gore, Vera Sazonova, and Paul L. McEuen, “High performance electrolyte-gated carbon nanotube transistors”, Nano Letters 2, 869 (2002)
Reference 4 : Wei Zhao, Chulho Song, and Pehr E. Pehrsson, “Water-Soluable and Optically pH-Sensitive Single-Walled Carbon Nanotubes from Surface Modification”, Journal of the American Chemical Society , Volume 124, Number 42, 2002, pages 12418-12419
Reference 5 : Axel Hagen and Tobias Hertel “Quantitative Analysis of Optical Spectra from Individual Single-Wall Carbon Nanotubes”, Nano Letters, 3, 383 (2003)
Reference 6 : M. S. Dresselhaus, G. Dresselhaus, and Ph. Avouris (Editors) “Carbon Nanotubes Synthesis, Structure, Properties and Applications” Topics in Applied Physics Volume 80, Springer-Verlag Berlin Heidelberg Germany 2001, ISBN 3-540-41086-4
Reference 7 : Shu Peng et. al. “Carbon Nanotube Chemical and Mechanical Sensors”, Conference Paper for the 3 rd International Workshop on Structural Health Monitoring
Reference 8 : C. Kilic et. al. “Variable and reversible quantum structures on a single carbon nanotube”, Condensed Matter 0011309 v1, 17 Nov. 2000
Reference 9 : O. Gulseren et. al. “Reversible Band Gap Engineering in Carbon Nanotubes by Radial Deformation”, Condensed Matter 0203226 v1, 11 Mar. 2002
Reference 10 : S. Peng and K. Cho “Nano Electro Mechanics of Semiconducting Carbon Nanotube”, Journal of Applied Mechanics , Volume 69, July 2002, pages 451-453
Reference 11 : Michael J. O'Connell et. al. “Band Gap Fluorescence from Individual Single-Walled Carbon Nanotubes”, Science Volume 297, 26 Jul. 2002, Pages 593-596.
BRIEF DESCRIPTION OF THE DRAWINGS
Two preferred embodiments of the present invention will be set forth in detail with reference to the drawings, in which:
FIG. 1 is a graph showing the optical absorption wavelength of a nanotube versus the degree of deformation;
FIG. 2 is a schematic diagram showing a sensor according to the first preferred embodiment, which exploits the phenomenon of FIG. 1 ;
FIG. 3 is a graph showing a density of states in nanotubes and in particular showing transitions between van Hove singularities;
FIG. 4 is a pair of graphs showing optical absorption modulation of nanotubes due to Fermi level modulation; and
FIG. 5 is a schematic diagram showing a sensor according to the second preferred embodiment, which exploits the phenomena of FIGS. 3 and 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Two preferred embodiments of the present invention will be set forth in detail with reference to the drawings, in which like reference numerals refer to like elements throughout.
A first preferred embodiment will now be set forth with reference to FIGS. 1 and 2 . FIG. 1 shows the optical absorption spectrum of a carbon nanotube as a function of the degree of deformation. The left column shows various states of deformation, from no deformation at all (top) to extreme deformation (bottom). The right column shows the absorption spectrum for each degree of deformation. The notch, indicating the optical absorption wavelength, moves to the left, indicating absorption at lower wavelengths, as the deformation decreases.
FIG. 2 shows a magnetic field sensor 200 based on this effect. The parameter to be measured is converted into a physical compression on a nanotube film 202 on an optical surface. In the case of the magnetic field sensor 200 , a magnetostrictive material 204 such as Terfenol-D is used to create this compressive force, represented in FIG. 2 as a strain vector V, as a function of the strength of the magnetic field. This compressive force flattens the nanotubes in the film 202 to a certain degree, and this in turn shifts the wavelength at which the nanotubes absorb light.
The nanotube film 202 is disposed between two optical elements 206 , 208 , which define a cavity 210 between them. In a transmissive embodiment, each of the optical elements 206 , 208 has a first optical face 212 facing the cavity 210 , a second optical face 214 not facing the cavity, and an internal, 45-degree reflector 216 . The second optical face 214 in each optical element 206 , 208 is an input or output port for input light L I or output light L O and can be connected to an optical fiber (not shown) or the like as needed. Within each optical element 206 , 208 , the reflector 216 defines an optical path between the first and second optical faces 212 , 214 .
Input light L I enters the first optical element 206 and is directed through the nanotube film 202 . The force applied by the magnetostrictive material 204 causes a shift in the optical absorption wavelength, as explained above and shown in FIG. 1 . Thus, a spectrum of the output light L O has a notch at the shifted optical absorption wavelength, caused by absorption of light at that wavelength by the nanotube film 202 . An analysis of the spectrum of the output light L O allows an easy determination of the location of the notch and thus of the shift in the optical absorption wavelength. That shift in turn allows a determination of the amount of force applied and thus the physical quantity to be sensed (in this case, the magnetic field).
For this sensor concept, we do not need anything close to total bandgap closure as discussed in the above research reports. We need only a very small, but measurable amount of shift in the nanotube optical absorption wavelength that falls within the wavelength bandwidth of a typical WDM channel. A change in the optical absorption wavelength on the order of nanometers or perhaps up to tens of nanometers would be sufficient. This amounts to a compression of the nanotubes by only on the order of one or two percent at most. It has been calculated based on the published compressive modulus of carbon nanotubes that this compressive force can easily be attained in practice.
This technique achieves light amplitude independence in the following way. The information regarding the parameter being measured resides in the point at which the nanotube absorbs light and this can be measured in a number of ways. As long as the logic making the determination of the measured parameter has enough light to detect and adequately determine the wavelength at which the nanotube is absorbing, then the measurement can be made. As the light amplitude gets larger or smaller the wavelength at which the nanotube absorbs does not change and the way to measure this can be done on an amplitude independent manner as is well known in the art.
Any parameter that can be converted into a compressive force on the nanotubes can be measured by this technique. Current can be measured by using the fact that a current gives rise to a magnetic field, as is often done in current measuring sensors, and then measuring the magnetic field as described above. Temperature can be measured by utilizing a material that changes dimensions with temperature, as many materials do to a large degree. This dimensional change is then used to affect a compressive force on the nanotubes. Voltage can be measured by utilizing a piezoelectric material to convert voltage into a dimensional change of a material and likewise affect a compressive force on the nanotubes.
A second preferred embodiment will now be set forth with reference to FIGS. 3-5 . The optical transition between the first pair of van Hove singularities, termed S 11 in FIG. 3 , may be strengthened or weakened by altering the Fermi level [Reference 4 ]. This is because the electrons in the ground state of this particular optical transition are very near the Fermi level to start with. If the Fermi level is changes, a greater number of electrons may be available, which strengthens the optical absorption, or a fewer number of electrons may be available, which weakens the optical absorption strength. This phenomenon is shown in FIG. 4 , which is excerpted from the work of Zhao in Reference 4 .
The interesting thing to note is that it is only the strength of the first optical transition, S 11 , that is modified by altering the Fermi level. The strength of the second optical transition, designated S 22 in FIG. 3 , is not affected at all, as can be seen in FIG. 4 . This is because the electrons in the ground state of transition S 22 are far away from the Fermi level and a modulation of the Fermi level does not alter the number of electrons available for this optical transition. The ratio of the strength of the S 11 to S 22 optical transitions as a function of the pH of the electrolyte is very linear.
A sensor based on this phenomenon is shown in FIG. 5 as 500 . The general approach is that the parameter to be measured causes the Fermi level to be changed. The sensor 500 of FIG. 5 , like the sensor 200 of FIG. 2 , has optical elements 206 and 208 and a nanotube film 202 . However, the optical elements 206 and 208 define between them a cavity 510 containing not only the nanotube film 202 , but also an electrolyte, semiconductor or other material 520 for creating a free charge, the material 520 being connected to a voltage 522 to be measured.
In the case of FIG. 5 , it is voltage 522 that is being measured that creates an electric field that drives charge either to or away from the nanotube surface, depending on the direction of the electric field and the sign of the free charge. The material 520 used to create the available free charge may be an electrolyte as in References 3 and 4 , or it may be a semiconductor material in close proximity or even coating the nanotube. The charge may be generated by a material near the nanotube through a very thin layer of dielectric material, such as the so called “high k” dielectric materials, where k stands for the dielectric constant of the material. High k, and even super-high k dielectric materials are being pursued in nanotube research because the electric field must be generated very near the nanotube surface to be effective. It has been found that normal dielectric materials break down when the very thin layers needed to get the charge near the nanotube surface are employed.
The sensor measurement technique that achieves light amplitude independence is to use the ratio of the received light signal at two wavelengths, where one wavelength is centered at the S 11 transition and the other is centered at the S 22 transition. As long as the ratio is used to compute the value of the parameter being measured, the optical losses through connectors and the like will be the same for both wavelengths, and the ratio will be unaffected by these losses. Thus, the detection is independent of light amplitude.
A variation of the sensor 500 uses the fact that carbon nanotubes have been found to fluoresce brightly [Reference 11 ] undergoing a process termed direct bandgap fluorescence. In this process light is absorbed at the S 22 transition wavelength and the nanotube sheds the absorbed light energy by emitting a light photon at the S 11 wavelength. Since transitions between van Hove singularities are involved similar to the discussions above, this process is termed direct bandgap fluorescence and can be very efficient. More typically in conventional fluorescence, emission follows a complicated path to de-excitation that leads to the emission of a fluorescence photon with some degree of probability, and is therefore much less efficient.
Therefore a variant of the above sensor design can be disclosed that utilizes fluorescence instead of absorption at the two bands, S 11 and S 22 . The sensor design utilizing fluorescence would be diagramed the same as the sensor 500 of FIG. 5 . In the first technique, two light sources are needed. One light source is centered at the wavelength of absorption band S 11 and the other is centered at the wavelength of absorption band S 22 . The ratio of the received light is indicative of the parameter being measured.
In this second approach using direct bandgap fluorescence, only one light source is needed, and this is the main advantage of this approach. This light source is centered at the wavelength of absorption band S 22 . At the receiver end of the fiber, light is still detected at both wavelengths corresponding to S 11 and S 22 . Now the light received at wavelength S 11 is due to fluorescence from the nanotubes, which act like light sources in effect. Determining the ratio of light power received at both wavelengths S 22 and S 11 still remains the basis for making a determination of the parameter being measured by the sensor. In this case the strength of the fluorescence will follow the amount of light power receive at the nanotubes at the S 22 wavelength, so the ratio of the light power received at the two wavelengths is still a light amplitude independent manner of making a measurement of a parameter. All optical losses downstream of the nanotube sensor will be in common with both S 22 and S 11 wavelengths as well, so that light amplitude independent operation is maintained.
While two preferred embodiments have been set forth in detail above, those skilled in the art who have reviewed the present disclosure will readily appreciate that other embodiments can be realized within the scope of the present invention. For example, any wavelength-dependent change in the absorption of the nanotubes can be detected and used in a sensor, which would still operate independently of light amplitude. Moreover, the sensor can be either transmissive or reflective; in the latter case, one of the optical elements is a mirror. Therefore, the present invention should be construed as limited only by the appended claims. | A passive optical sensor operates independently of light amplitude by using a semiconducting carbon nanotube material. The material has an optical property dependent on wavelength, e.g., wavelength of absorption, ratio of absorptions at two wavelengths, or fluorescence at one wavelength in response to light at another wavelength. The property is changed by compressing the material or exposing the material to a charge. Light is passed through the material so that the change in the property can be detected. | 1 |
This application is a continuation of international application number PCT/ES01/00365,filed on Oct. 2, 2001 (status, abandoned, pending, etc).
The invention refers to a faucet for filling tanks which is of the type known as silent and/or fast closing.
It essentially concerns a faucet that in general possesses a structural and functional base like the faucet for patent P-9400045, but with the incorporation of various improvements and new devices that imply a more efficient functioning in all senses, principally with regard to the advantage of functioning correctly under any pressure of the water network feeding that faucet, and with regard to the reduction of noise.
As it occurs with the faucet of patent P-9400045, the faucet of the invention can function as a normal faucet, in other words sealing by means of the thrust of the rubber piece when the float or float rises up in the absence of pressure in the water supply.
BACKGROUND OF THE INVENTION
Different types of fast closing or silent faucet are known for filling toilet tanks, and they all have a close functional relationship.
In principle, the water discharges into the tank and the sealing is achieved by the effect of the pressure exerted by the water network itself on the rubber seal. For this, the closing is instantaneous and fast, thereby eliminating progressive closing which causes noise.
So far, it can be asserted that this type of faucet presents important technical problems, especially due to the fact that it only works at very specific pressures, in such a way that when the values are high these conventional faucets very easily become blocked and unusable.
Others, which work with micrometric measurements for the passage of water, also very easily become blocked and of course cease to work.
On the other hand, present-day fast closing faucets for filling tanks do not function with water at high pressure.
A faucet is known that seems to function acceptably and overcomes the problems mentioned in the preceding paragraphs, though it is very large and costly to produce, and its functioning becomes irregular at high pressures.
Among the registers that are known and which have some of the drawbacks mentioned above can be mentioned patent P-9001516, utility model 244.814, utility model 246.739, etc.
As an antecedent of the feed faucet for tanks that uses a vertical tube for ducting the water to the bottom of the tank and eliminating noise mention can be made of: utility model 271.378, though it employs a mechanical sealing system by thrust of the arm associated with the float.
Patent P-9400045 refers to a faucet for filling tanks which possess a fast and silent closing during the filling of a toilet tank, at the same time as functioning with high and low pressures. This is a dual functioning faucet: on the one hand it acts as a fast closing and silent faucet, taking advantage of the actual pressure of the water in the network for carrying out the sealing, and on the other, in the absence of pressure, it functions as an ordinary faucet, in other words by means of the thrust that the rising of the water level exerts on the arm of the float or float.
DESCRIPTION OF THE INVENTION
The faucet for filling tanks which constitutes the object of the invention is characterised in that it functions efficiently at any pressure covering a wide range of values.
In principle, it includes a structural base like the faucet of patent P-9400045.
So, the new faucet consists of a casing with a water inlet duct and an outlet duct through which the liquid flows to the outside in order to be able to fill the tank. Coupled to this casing by means of the collaboration of a threaded locking ring is a tubular piece so that this and the casing together shape an internal cavity in which is housed a set of elements for controlling the sealing and release of the faucet.
Within the internal cavity there are two facing elastic rubber pieces, forward and rear, each being interposed between the casing and the tubular piece, and between the two rubber pieces there exists an intermediate chamber that links with the other rear chamber via an opening in the second rubber piece, this rear chamber presenting a constriction corresponding to the tubular piece, where an intermediate body is fitted provided with a longitudinal opening, at the same time as being in contact with a piston on which acts the rocker arm linked to the corresponding float or float.
The facing rubber pieces present a different structure from that presented by the rubber pieces of patent P-9400045, at the same time as being linked and associated in a way that is also different.
The opening of the rear rubber piece is over-dimensioned with the aim of helping to release the pressure in the chamber confined between the two rubber pieces during flushing.
The intermediate body presents a very different structure from that presenting by the moving body of patent P-9400045. Moreover, the new faucet incorporates a compensating spring located between the intermediate body and the rear rubber piece. This spring helps the recovery of the expansion undergone by the rear rubber piece during the sealing.
The intermediate chamber confined between the two facing rubber pieces is connected to the inlet duct of the water network via a narrow opening made in the forward rubber piece and in which comfortably fits a rod integral with a central piece provided with certain holes for allowing the passage of the fluid. Concentric with this inlet duct is another larger one that connects the first duct with the tank via the outlet pipe or duct, preferably vertical. Moreover, these two concentric ducts are related one with the other by means of the forward rubber piece which, depending on its position, will permit the passage of water from the inlet duct to the larger concentric duct and from here to the outlet pipe.
These two concentric ducts are separated by an annular partition, the free edge of which can be used for seating the forward rubber piece when the sealing takes place in order to prevent the passage of fluid. That free edge of the annular partition presents a curved-convex shape permitting a more effective seal when the forward rubber piece is seated on it.
When the tank is empty, the flow of liquid will pass through the inlet duct until it reaches the larger duct, passing from this to the tank by means of the outlet pipe. During this stage of filling, and thanks to the pressure of the water in the network, a tapping takes place of the fluid via the narrow opening made in the forward rubber piece, and the fluid floods the intermediate chamber and straight away crosses the opening of the rear rubber piece in order to flood the rear chamber as well. This rear chamber does not include a drainage duct as in the case of patent P-9400045. Instead, drainage has been provided via the thread where the locking ring of the tubular piece couples. In this way, excess pressure is released from the faucet during the filling of the tank.
When the tank reaches the proper level, the circulation of the fluid is automatically cut off by means of the float linked to the lever that will act on the piston, which then becomes axially displaced towards the interior, as it moves pulling along the intermediate body with the longitudinal opening which is sealed by that piston, that body covering the opening of the rear rubber piece. In that way, the circulation of the fluid is detained in the intermediate chamber where the pressure of the water will push the two rubber pieces in opposite directions in such a way that the forward rubber piece will prevent the passage of fluid from the inlet duct to the outlet duct.
When the tank is emptied, the piston returns to its initial position and with it all the other elements, thereby releasing the closing pressure generated in the intermediate chamber, with which the circulation of the water will commence again until the tank is filled once more.
This, piston incorporates at its internal end a rubber seal which is what closes the narrow longitudinal opening of the intermediate body.
The fine rod crossing the opening of the forward rubber piece regulates the passage of the fluid into the intermediate chamber. Similarly, the displacement of the forward rubber piece on the rod favours the continual cleaning of the small concentric passage that exists.
In addition to sealing the opening of the rear rubber piece when appropriate, the intermediate body which incorporates the longitudinal opening also receives the recoil thrust following the sealing. For this reason, provision has been made so that it is forced to stop on an intermediate step of the tubular piece housing the piston, in such a way that it retains the recoil pressure of the rear rubber piece and this is not excessively transmitted to the float via the piston; these latter two elements support solely the sealing pressure of the longitudinal opening of the intermediate piece.
The faucet of the invention also functions perfectly when the flow of water supplied by the network is minimal, in other words, when it is “drop by drop”.
The vertical outlet pipe is telescopic for being adapted to the depth of the tank in order to ensure that the outlet of the water is made below the minimum level of water left in the tank after flushing in order to thereby reduce the noise of the filling.
The float is able to include a small tank that will be filled with fluid, the weight of which will improve the descent of the float once the faucet has been actuated for flushing the tank.
In the outlet duct for the fluid there is a tapping where a small float has been provided by way of a non-return valve which also makes the faucet more silent so that during the filling of the tank this tapping is kept sealed, thus preventing the emission of sounds.
When that float ceases to float due to the absence of water once the faucet is sealed, it unblocks the opening located above it, releasing it for the purpose of permitting the entrance of air and thus avoiding the non-return effect.
In order to facilitate a better understanding of this descriptive report, some figures are included below in order to represent the object of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a sectioned elevation view of the assembly of the faucet for filling tanks, forming the object of the invention. It includes a side inlet for water.
FIG. 2 shows an enlarged view of part of the faucet of the invention.
FIG. 3 shows an elevation view of the faucet.
FIG. 4 shows a view of an intermediate body and a piston forming part of the assembly of the faucet of the invention.
FIG. 5 shows a view of a float of the faucet including a lower cover provided with an air chamber.
FIG. 6 shows a perspective view of a faucet including a lower entrance for water provided in a vertical direction.
FIG. 7 shows a view of part of the faucet of the preceding figure.
FIG. 8 shows a perspective view of a float different from that shown in the preceding figures.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Described below is an example of an embodiment of the invention following the numbering adopted in the figures.
The faucet consists of a casing 1 that includes in principle an inlet pipe or duct 2 and an outlet duct or pipe 3 .
Coupled to the casing 1 , with the aid of an external threaded locking or fastening ring 4 , is a tubular piece 5 in such a way that between it and the casing 1 there is an internal cavity defined in which are housed a series of elements controlling the sealing and passage of the fluid.
Inside the internal cavity there exists a wider zone housing two facing rubber pieces made of an elastic material: one forward 6 and the other rear 7 , with these two being interposed between the casing 1 and the tubular piece 5 . The two elastic rubber pieces 6 and 7 are actuated by means of a union ring 8 of double conicity, which forms the core or frame of the perimeters of the rubber pieces, particularly during the action of tightening the unit. In this way we can exert greater pressure on the perimeters of those rubber pieces without deforming them, and thereby ensure the absence of leaks, even with very high water pressures.
Between these two elastic rubber pieces 6 and 7 there exists an intermediate chamber 9 which is connected in one direction with a rear chamber 10 via an over-dimensioned opening 11 of the rear rubber piece 7 . The purpose of this opening is to produce a faster release of the pressure existing in the intermediate expansion chamber 9 at the moment of proceeding to flush the tank, with which the immediate unsealing of the faucet will take place.
Other conventional faucets have always used rubber pieces with capillary openings which were difficult to unseal properly, which meant that the release of pressure was poorer than in the method we have stated above.
The rear chamber 10 of the tubular piece 5 includes a constriction 12 where an intermediate body 13 is fitted provided with a longitudinal drainage hole 14 . The sealing surface of the end of that longitudinal drainage hole 14 must be minimal, and in this case the seating has been rounded so that the elastic stub 15 makes a closure with the minimum contact surface. At the same time it makes contact with an elastic stub 15 inserted frontwise onto a piston 16 on which will act a lever 17 associated with a vertical shaft 18 which threads into part of a float 19 , in order to therefore be able to regulate the height of the float so as to vary the volume of water in the tank.
The intermediate body 13 consists of an upper section 20 of tubular structure in which certain longitudinal ribs 21 are made, and a lower section 22 of conical shape facing the opening of the hole 11 of the rear rubber piece 7 . The tubular section 20 of the intermediate body 13 is guided against the lower part of the constriction 12 of the tubular piece 5 , at the same time as the lower part of the piston 16 is in turn housed within the tubular section 20 of the intermediate body 13 causing the closure of its conical section 22 on the over-dimensioned opening of the rubber piece 7 , and of the elastic stub 15 of the piston 16 on the longitudinal opening 14 .
The constriction 12 of the tubular piece 5 possess an upper step 23 where an annular ledge 24 integral with the piston 16 acts as a stop in order to limit the axial travel of the piston 16 towards the outside. This annular ledge 24 , in collaboration with the upper step 23 , ensures a correct closure in order to prevent the escape of fluid in the vertical direction during the unsealing. There is normally a small escape that is expelled which does not have any great importance.
The upper chamber 10 contains a compensating spring 25 which acts as a stop against the rear rubber piece 7 and against the tubular piece 5 . This spring 25 favours the return of the rear rubber piece 7 to its original position during unsealing, quickly compensating for the expansion undergone by the rear rubber piece 7 during the sealing.
When the water reaches as far as the rear chamber 10 , it also floods the interstices existing between the longitudinal ribs 21 of the intermediate body 13 and the tubular piece 5 . That rear chamber 10 possesses an outlet drainage via the thread 26 existing between the threaded locking or fastening ring 4 and the casing 1 , and for this the said thread has at least one smooth longitudinal narrow zone interrupting that thread. In this way, the fluid inside the rear chamber 10 is discharged to the outside via that smooth zone. The tubular piece 5 includes some radial openings 27 for facilitating the passage of the water from the rear chamber 10 as far as the smooth zone for drainage made in the thread 26 .
The lever 17 links two lateral stubs 28 integral with the tubular piece 5 , at the same time as the end of the lever 17 includes a short transverse shaft 29 that fits into a recess 30 of a swinging piece 31 which, by means of another short shaft 32 , links to a complementary slot 33 of the tubular piece 5 . Finally, this swinging piece 31 fits into a central recess or undercut 34 of the piston 16 via a short central shaft 35 with the aim of vertically displacing the piston 16 . This set of pieces that act on the piston 16 multiply the thrusting force of the float 19 , an increased thrust that becomes necessary when working with high pressures.
The recess 34 collaborates in keeping the pieces 16 and 13 fitted even when the faucet is dismantled. The retaining means for those pieces 16 and 13 are materialised by means of the undercuts 60 of the tubular section 20 , and the stops or undercuts 61 provided in the piston 16 prevent the accidental separation of these pieces following the opening or removal of the faucet due to dissociation of the pieces 1 and 5 , and they also remain joined to the lever 31 thanks to the recess 34 . We thus manage to maintain all these pieces connected to the body 5 and the threaded ring 4 , preventing their desegregation.
It can be pointed out that when the flushing of the tank takes place, the float 19 descends and raises up the piston 16 providing a clear route for the pressure that is generating the sealing and so the filling of the tank commences again.
The compensating spring 25 acts as a stop against the tubular piece 5 at the same time as fitting into an annular channel 36 of that tubular piece 5 .
The closure of the over-dimensioned opening 11 of the rear rubber piece 7 is done by means of the conical surface of the lower section 22 of the intermediate body 13 . This conical body permits proper sealing no matter what the incoming pressure might be, since its conical surface allows the sealing zone to be progressive as the pressure increases.
The intermediate chamber 9 confined between the two elastic rubber pieces 6 and 7 , connects with the rear chamber 10 by means of the opening 11 and also connects in the other direction with the inlet duct or pipe 2 of the water network via a narrow opening 37 where a rod 38 comfortably fits integral with a central piece 39 provided with some gaps for permitting the passage of the fluid. Concentric with this inlet duct 2 there exists another larger duct 40 which is connected to the tank via two telescopic pipes 41 and 42 in such a way that the larger diameter one 41 is connected to the outlet duct 3 . Both pipes are preferably associated with each other with the aid of a friction rubber piece 43 in order to prevent undesired noises and vibrations.
This telescopic pipe 42 is adapted to the depth of the tank in order to ensure that the outlet for the water is made below the minimum water level in order to thereby reduce as much as possible the noise of the filling.
The two concentric ducts 2 and 40 are connected by means of the forward rubber piece 6 in such a way that, depending on its position, it will permit the passage of water from the inlet duct 2 to the larger concentric duct 40 and from there to the outlet duct 3 connected to the two telescopic pipes 41 and 42 .
The two concentric pipes 2 and 40 are separated by an annular partition 44 , the free edge 45 of which is suitable for pressing on the forward rubber piece 6 when the closure of the faucet takes place, with which the entrance of water into the tank will be cut off. That free edge of the annular partition 44 is given a rounded finish so that the sealing in this zone can be more efficient.
In addition, it can be stated that the rounded edge 45 of the annular partition 44 lies below the seating plane of the forward rubber piece 6 in order to ensure the passage of water at any pressure no matter how low it might be.
When the tank is empty, the flow of liquid will pass through the inlet duct 2 as far as reaching the larger duct 40 , passing from this to the tank by means of the outlet pipe 3 . During this stage of filling and thanks to the pressure of the water in the network, a tapping takes place of the fluid via the narrowing opening 37 made in the forward rubber piece 6 , and this fluid floods the intermediate chamber 9 and straight away crosses the over-dimensioned opening 11 of the rear rubber piece 7 , also flooding the rear chamber 10 , which includes drainage as mentioned earlier which, in collaboration with the longitudinal opening 14 of the intermediate body 13 , advantageously prevents any pressure increase in the chamber 9 during the filling process, which would lead to anomalous functioning.
When the tank reaches the proper level, the circulation of the fluid is automatically cut off by the float linked to the lever 17 , which will act on the piston 16 , displacing the latter axially towards the interior, as it moves pulling along the intermediate body 13 provided with the longitudinal opening 14 , said intermediate body 13 covering in its conical section 22 the over-dimensioned opening of the rear rubber piece 7 . In this way, the circulation of the fluid is detained in the intermediate chamber 9 where the pressure of the water will push the two rubber pieces 6 and 7 in opposite directions in such a way that the forward rubber piece 6 will prevent the passage of fluid from the inlet duct 2 to the outlet duct 40 while the rear rubber piece 7 produces a thrust on the intermediate body 13 , which is sealed by the rubber piece 15 of the piston 16 . Until the complete sealing of the faucet assembly is carried out, the piston 16 receives the thrust of the piece 13 which is in turn pushed by the rear rubber piece 7 which has been displaced against the action of the lever 17 . Therefore, even the float experiences this thrust which translates into a slight sinking. With this sinking we apply an additional thrust which increases the thrust of the piston 16 on the intermediate piece 13 , ensuring the closure of the longitudinal opening with any type of pressure. In this manner, a closed set of forces is established, where the float thrusts in the opposite direction to the thrust produced by the rear rubber piece 7 . Nevertheless, the piston 16 finally only supports the pressure of the internal fluid of the intermediate chamber 9 transmitted via the duct 14 and the intermediate body 13 .
When the tank is emptied, the piston 16 returns to its initial position. In this way, the longitudinal opening 14 of the intermediate body 13 is opened and allows the pressure accumulated in the intermediate chamber 9 to escape, with which all the elements return to their original position and the circulation of the water is re-established again until the tank is filled once more.
The fine rod 38 crossing the opening 37 of the forward rubber piece 6 regulates the passage of the fluid into the intermediate chamber 9 , in such a way that it is not necessary to make an opening of very small dimensions, which would easily become blocked, and which is in any case technically very difficult to carry out owing to the material characteristics of the rubber. Similarly, the small displacement of the forward rubber piece 6 on the rod 37 favours the continual cleaning of the small concentric passage that exists.
In addition to sealing the over-dimensioned opening 11 of the rear rubber piece 7 when appropriate, the intermediate body 13 which incorporates the longitudinal opening 14 also receives the recoil thrust of the rubber piece 7 following the sealing. The spring 25 ensures the original position of the rubber piece 7 and maintains the travel of the pieces 13 , 16 and 19 , necessary for carrying out the closure correctly.
The central piece 39 supporting the rod 38 and which is located in the inlet duct 2 can be independent, in other words, inserted in its location, or it can form an integral part of the actual casing 1 .
Moreover, we will describe the second functioning option of this new faucet that is produced when the supply network fails to provide enough pressure, or when there is minimal flow, in other words, “drop by drop” flow of fluid. It is then that the faucet demonstrates its versatility, mechanically (without the intervention of fluid pressures) carrying out the sealing. The float or float thrusts the piston 16 towards the interior as the level of the water rises in the tank, this thrust being transmitted to the intermediate body 13 which eventually makes contact with the rear rubber piece 7 and this in turn bends towards the interior and produces central contact with the forward rubber piece 6 which is pushed against the closure zone of the inlet duct 2 , producing the cutting off of the passage of fluid towards the outlet duct 3 .
In terms of the forward rubber piece 6 , it receives the entrance of fluid under pressure through the opening 37 , as we have said earlier; nevertheless, this capture of fluid needs to be made before the flow loses pressure when it passes to the outlet duct 3 . To achieve this, the said rubber piece 6 is provided with a central ledge 46 introduced inside the inlet duct 2 very close to the central piece 39 . In this way, the intake of fluid is done at full pressure, which favours the correct functioning of the faucet. That central ledge 46 possesses an exterior corner 47 , rounded in shape in order to facilitate the circulation of fluid in that zone, thus preventing undesired whistles, noises and vibrations during the closing.
Delving further in the silent characteristics of the new faucet, it can be pointed out that this quality is appreciably favoured to the degree that there does not exist any reduction in the passage of water in the outlet 3 and it is even possible for this outlet duct 3 to present a greater rate of flow; in both cases, the whistling of the flow of liquid becomes noticeably less since there is no narrowing, which favours the silent operation of the faucet.
The outlet duct 3 contains a tapping 48 where a small float 49 has been inserted by way of a non-return valve in order to make the faucet more silent if possible, in such a manner that during the filling of the tank, this tapping 48 is kept sealed, thus preventing the outlet of possible hums or noises, while, once the tank is full, the tapping is kept open in order to ensure the non-return effect.
The float 19 can incorporate a small partition or rail 50 in its upper base which gives rise to a small tank of low height which can be filled with water, thus generating an additional weight which is very useful for improving the descent once the flushing mechanism has been pressed.
Optionally, the float 19 could be enclosed via its lower base by means of a cover 51 , which would prevent noises caused by the bubbling of water generated if it were open, and which is produced when the air inside the float exits as the float sinks. This cover 51 can also perform the role of an additional tank for water in a manner similar to that provided for in the preceding paragraph. In this case, the float 19 will include two small holes 52 and 53 at the desired height for permitting the entrance of water and the exit of air, respectively. As the tank fills up, the water becomes introduced through the holes 52 and 53 within the actual float 19 up to a certain level, finally forming an upper air chamber within that float 19 . When flushing takes place, the water found inside the float 19 generates an additional weight that is very useful for improving the descent once the flushing has been performed. This additional weight will start to have an effect when the water level of the tank descends to below the small holes 52 and 53 of the float 19 .
Moreover, FIG. 5 shows a cover 51 ′ which possesses at least one auxiliary air cavity 54 for improving the additional thrust of the float 19 during its flotation, particularly when the sealing of the faucet takes place. In that moment, the interior air tank does not act since the pressures have become equalised.
As has been stated above, the interior water tank of the float 19 will not start to act until the level of liquid in the tank descends to below the holes 52 and 53 of the float 19 .
The larger duct 40 , concentrically provided with an inlet duct 2 , possesses a narrow tubular extension for drainage 55 .
On its exterior face the forward rubber piece 6 possesses an annular channel of curved section 56 for improving its flexing.
The piston 16 possesses a longitudinal rib 57 which fits into and is guided in a complementary groove 58 made in the tubular piece 5 . In this manner, the positioning of the piston 16 is ensured, at the same time as preventing any unwanted rotation of it.
The tubular section 20 of the intermediate body 13 consists of various radial fins 59 , the upper ends of which are finished in some small internal flanges 60 complemented with a slight annular step 61 of the piston 16 . In addition, this tubular section 20 includes some wide longitudinal recesses 62 permitting the passage of the fluid.
On the other hand, the lower conical-shaped section 22 includes a central extension 63 that is projected upwards the inside of the tubular section 20 , in such a way that said extension 63 of the drainage hole 14 acts as a seal against the elastic stub 15 of the piston 16 .
As it occurs with patent P-9400045, the faucet of the invention is applicable to different formats of water inlet, both a side inlet 2 as has been represented in FIGS. 1 and 3, and a lower inlet 2 ′ telescopic in the vertical direction, as has been essentially represented in FIG. 6, or even a fixed vertical inlet.
The float 19 possesses two linking mechanisms for the coupling of the threaded vertical shaft 18 : one preferably exterior 64 , 64 ′, and the other interior 65 applicable when the water inlet is lower 2 ′ and the outlet pipe 41 is displaced with respect to the vertical of the entrance pipe (FIG. 6 ). In this way, it is merely necessary to manufacture a single float 19 which will be able to be adapted both to the faucet with side water inlet 2 and to the faucet with lower inlet 2 ′ in the vertical direction, whether fixed or telescopic.
In the case of the lower water inlet 2 ′, the telescopic coupling 41 and 42 for the water outlet will be arranged in a vertical direction close to and parallel with the other vertical direction where the lower inlet pipes and ducts 2 ′ are to be found. Therefore, in this second case it is necessary to couple the threaded vertical shaft 18 on the interior recess 65 of the float 19 . Moreover, in this second case of the lower inlet 2 ′, this inlet is arranged in the same vertical as the set of elements of the faucet that carry out the sealing of it.
In the second embodiment of the faucet where the water inlet 2 ′ is lower, the outlet duct 41 is integral with the moving telescopic section of the inlet 2 ′. In this case (FIG. 7 ), provision has been made for the upper pipe 66 of the telescopic inlet assembly 2 ′ to have a side duct 67 ending in a double cavity 68 and 69 for facilitating the coupling of the anti-noise device 3 , 48 and 49 . Coupled to the lap formed by the double cavity 68 and 69 will be the telescopic outlet pipes 41 and 42 which constitute the guide for the float 19 . The side duct 67 is not closed, which means that we can manufacture the upper pipe 66 in a single block. Located in the upper part of that upper pipe 66 are two distinct elements for providing the closure of the faucet. The side outlet duct 67 will be closed by means of a plug 70 for the guiding of the water towards the outlet pipes 41 and 42 .
The upper pipe 66 fitted with the outlet 67 will be able to be coupled to any water outlet element, whether this be the pipes 41 and 42 or any other analogous device.
The interior mechanism 65 simply consists of a threaded recess where the thread of the vertical shaft 18 will couple, being able to regulate the height of the float 19 .
On the other hand, the exterior mechanism 64 ′ is defined on the basis of a tilting tubular piece 71 which is articulated by means of two facing stubs 72 to two complementary holes 73 made in certain parallel arms 74 integral with the float 19 , in such a way that the direction of the facing stubs 72 of the tilting piece 71 , and therefore of the articulation, is perpendicular to the threaded vertical shaft 18 , which in principle will be coupled to an interior thread 75 of the tilting tubular piece 71 .
Moreover, it can be stated that although the association of the vertical shaft 18 to the respective linkage mechanism of the float 19 is done by means of threading, this could also be achieved by any other means.
As an alternative embodiment, provision is also made for a float 19 ′ in which the connection to the vertical shaft 18 is made by means of an arm 76 fitted with two connection means 64 , 64 ′, with that vertical shaft 18 .
In this way, the force is transmitted on the float in the zone closest to its sliding vertical, with which we avoid any swinging or even blocking of the displacement, all this according to the degree of sliding of the material used, which is a determining factor for establishing the optimum relative movement between the different pieces.
Moreover, provision is also made for the use in either of the variants of the float described 19 , 19 ′, of the simple exterior mechanism 64 ′ for improving the connections of the rod or vertical shaft 18 with those floats.
With this simple mechanism 64 ′ we take away rigidity from the connection points, granting them a greater degree of articulation and generating tolerances that are very suitable for the transmission of forces between the different pieces.
In this sense, in FIG. 6 we see an example of application of this detail on the float 19 , defining the exterior coupling mechanism 64 ′ in replacement of the exterior coupling mechanism 64 materialised simply by means of a tubular recess.
Finally, it can be stated that, although the association of the vertical shaft 18 to the respective linkage mechanism of the float 19 is done by means of a thread, this could also be achieved by any other means. | The invention relates to a faucet for filling tanks known as silent and/or fast-closing faucets. The faucet comprises a basic structure and functionalities such as those disclosed in Patent 9400095. The device assembly controlling opening and closing of the faucet has important improvements in comparison with other conventional faucets and in comparison with the above-mentioned patent. The faucet also includes a lever system connecting the float and the piston acting upon the opening and closing device. In additional, improvement deals with the telescopic structure of the fluid outlet tubes to the tank in order to regulate the height thereof depending on the depth of the tank so that the fluid is always discharged into the water with the aim of preventing noises. | 5 |
TECHNICAL FIELD
[0001] The invention relates to an arrangement for storing and launching payloads, in particular an arrangement for storing and launching counter-measures, such as flares and chaff.
BACKGROUND ART
[0002] Arrangements for storing and launching payloads, such as counter-measures, being designed to be mounted on vehicles, such as an aircraft of the aeroplane type, are previously known. According to the state of the art, such arrangements comprise an elongate body provided with at least one launch opening. Such arrangements are mounted with the longitudinal direction of the elongate body essentially coinciding with the flight direction of the aircraft. The counter-measures being connected to a firing control unit for feeding firing signals to the counter-measures. The counter-measures can consist of passive means, such as chaff foil, but can also consist of flares, for example IR flares, or other active measures.
[0003] One problem is that unfavourable acoustic phenomenon, such as extremely high air induced noise and vibration levels, are generated due to the openings of the compartments, after firing of the counter-measures. The relative wind, due to the speed of the vehicle, interacts with the open, remaining cartridges of the compartments in which the counter-measures have been accommodated. The open compartments can act as barrels which oscillate at its inherent frequency. The acoustic phenomenon could be localised by target-seeking missiles and may also cause damage on the equipment, such as electric components, due to strong vibrations created.
[0004] The longitudinal extension and the number of openings of the compartments in the elongated body can be rather large. The protective effect of previously known vortex generators arranged in front of the compartments decreases with increasing length of the openings of the compartments.
[0005] Another problem is that previously known sound absorbing means, in arrangements according to the state of the art, generates turbulent flows that are difficult to control and results in high energy losses. The previously known sound absorbing means also contributes to an increased extension of the design of the arrangement in the longitudinal extension of the vehicle.
[0006] Yet another problem with the arrangements according to the prior art is the sensitivity for influence of the air flow that is affected by the speed and position of the vehicle.
[0007] An example of a previously known arrangement described as a dispenser which is used for launching counter-measures and provided with compartments, is described in document WO-A1-0059782. An elongated body of the dispenser is provided with fixed means, described as a spoiler, in front of the compartments for acting on the air stream and for creating a low dynamic pressure across the compartment openings.
[0008] From document U.S. Pat. No. 4,696,442 it is known to provide the exterior surface of an aircraft with a pair of vortex generators arranged right in front of an inlet opening in order to increase the mass airflow into the inlet.
SUMMARY OF THE INVENTION
[0009] One object of the present invention is to at least partially eliminate the drawbacks associated with the solutions known in the prior art.
[0010] Another object is to minimise the occurrence of acoustic phenomenon which are caused by the openings in compartments which have been emptied of payloads, such as counter-measures.
[0011] Yet another object is to prevent the occurrence of vibration disturbances which are primarily caused by inherent oscillations in compartments which have been emptied of payloads.
[0012] A further object is to provide an arrangement that is independent of the longitudinal extension and the number of openings of the compartments in the elongated body. Moreover, it is an object with the present invention to provide a solution that has a compact design, that not contributes to high energy losses, and that is insensitive to the position and speed of the vehicle.
[0013] The objects of the invention are achieved by means of an arrangement according to claim 1 .
[0014] Thus, air deflecting means are arranged on the side of the compartments, directing the air flow obliquely and crosswise over the openings, such that a stable laminar flow is provided over the openings. A layer of air is created that covers the openings. The aeroacoustic phenomenon and vibration disturbances are decreased or essentially eliminated.
[0015] By generating a laminar air flow over and across the openings, creating an air covering layer, a favourable low drag contribution is obtained. The creation of an air covering layer over and across the compartment openings has been shown to effectively counteract oscillations caused by the inherent frequencies of the compartments, since the laminar air flow near the openings of the compartments means low drag contribution and low energy.
[0016] By the arrangement of the air deflecting means according to the present invention, a compact design is reached, and which works independently of the longitudinal extension of the openings and the position of the vehicle, such as an attack or sideslip angle of the aircraft.
[0017] According to an embodiment, the elongate body is provided with at least two deflection means arranged in a row in the longitudinal direction of the elongate body. According to yet an embodiment, the elongated body is provided with at least two deflection means, arranged in parallel and in pairs, one on each side of one opening. At least one deflection means can be arranged adjacent and obliquely in front of the most forward opening. The elongated body can be provided with at least one deflection means along the longitudinal side adjacent each opening.
[0018] When at least two deflection means are arranged in parallel and in pairs, one on each side of one opening, first deflection means are arranged along one side of the launch opening, for redirecting an air flow to create a first air covering layer over and across the openings of the compartments. Then, second deflection means are arranged along another opposite side of the launch opening, for redirecting an air flow to create a second air covering layer over and across the openings.
[0019] The deflection means can be made movable. However, according to a preferred embodiment, the deflection means are fixed to the elongated body. In a further embodiment, a surface area of the deflection means, which surface area is facing the air flow in the direction of motion, can be altered. The rear side of the deflection means can be provided with a protrusion. An air redirecting surface of the deflection means is preferably arranged above the surface of the dispenser.
[0020] Further embodiments and advantages are described below with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will be described in greater detail below by way of illustration of embodiments and with reference to the attached drawings, in which:
[0022] FIG. 1 shows a side view of an aeroplane provided with an arrangement according to an embodiment of the invention for storing and launching counter-measures,
[0023] FIG. 2 shows, in the upper picture, a schematic side view of an arrangement according to an embodiment of the invention for storing and launching counter-measures, and in the lower picture a schematic top view of the same arrangement as in the upper picture,
[0024] FIG. 3A shows another schematic top view of an arrangement according to a further embodiment of the invention, and in FIG. 3B is shown a schematic top view of yet another embodiment of the arrangement,
[0025] FIG. 4 shows a schematic cross section view of the arrangement according to FIG. 2 , lower picture, along line A-A, and
[0026] FIG. 5A-C schematically shows various arrangements of air deflectors according to embodiments of the present invention.
DETAILED DESCRIPTION
[0027] An aeroplane 1 shown in FIG. 1 is provided with an arrangement 2 for storing and launching payloads, hereinafter described as counter-measures 5 . The arrangement 2 is hereinafter referred to as the dispenser 2 . The dispenser 2 has its longitudinal direction essentially coinciding with the longitudinal direction of the aeroplane 1 . An arrow 3 designates the direction of launching from the dispenser 2 . The character a designates the launch angle relative to the direction of movement of the aeroplane 1 when the counter-measures 5 are launched obliquely forwards and downwards. The trajectory 4 for a launched flare 5 is indicated by a broken line. During the time from when a flare 5 is activated for launch to when it reaches the position shown in FIG. 1 , sufficient time has elapsed for the flare 5 to have become a fully active decoy target in close proximity to the aeroplane 1 . According to FIG. 1 , the dispenser 2 is placed under a wing 6 near its attachment to the main body 7 of the aeroplane 1 . In this context, it should be noted that the dispenser 2 can also be placed further out on the wing 6 or directly on the main body 7 of the aeroplane 1 such as in a dispenser 2 ′ (a suitable position is only indicated by the arrow in FIG. 1 ) on top of the airplane.
[0028] The dispenser 2 is described in more detail with reference to FIGS. 2-3 . The dispenser 2 is designed as an elongate body 8 , partially shown in FIG. 2 , provided with at least one launch opening 10 used for storing the counter-measures 5 in compartments 11 . 1 , 11 . 2 , . . . , 11 . n . The counter-measures 5 being connected to a firing control unit (not shown) for feeding firing signals to the counter-measures. The compartments 11 . 1 , 11 . 2 , . . . , 11 . n are provided with openings 12 . 1 , 12 . 2 , . . . , 12 . n . The counter-measures 5 are preferably accommodated in cartridges 14 which can be of a type known in this field and will therefore not be discussed in detail here. The compartments 11 . 1 , 11 . 2 , . . . 11 . n can be of the same size or of different sizes and can accommodate identical or different types of counter-measures 5 . According to the embodiment disclosed in FIGS. 2-3 , the compartments 11 . 1 , 11 . 2 , . . . 11 . n are arranged side by side in rows creating a matrix pattern. According to the embodiment disclosed in FIGS. 2-3 , the compartments 11 . 1 , 11 . 2 , . . . 11 . n are designed to slope forwards 30° to 60° and preferably about 45° relative to the aeroplane 1 , which is depicted in FIG. 2 , upper picture. However, the cartridges can be arranged to lie with the opening side essentially perpendicular relative to the openings of the compartments. In principle, all geometrically possible positions can be considered for acting on the direction of launching and may be used.
[0029] The elongate body 8 is provided with deflection means. According to the embodiment shown in FIG. 2 , there are first deflection means 15 . 1 , a second deflection means 15 . 2 and a number of additional deflection means 15 . n placed on each longitudinal side of the launch opening, for acting on the air stream and for permanently creating an air covering layer 16 across and over the compartment openings 12 . 1 , 12 . 2 , . . . , 12 . n . The created air covering layer 16 , forms an air shield that decreases the acoustic effect/phenomena in the emptied compartments 11 . 1 , 11 . 2 , . . . , 11 . n when the counter-measures 5 have been launched.
[0030] FIG. 2 , upper picture, shows the dispenser 2 with the air covering layer 16 on an upper side S 1 . As described above, the dispenser can be placed under the wing, and consequently this upper side will be positioned on the lower side S 2 of the dispenser as illustrated in FIG. 1 .
[0031] The deflection means 15 . 1 , 15 . 2 . . . 15 . n , respectively, hereinafter also denoted as air deflector(s) can be in the form of a nozzle, a wing, a channel, a fin or the similar. According to an embodiment, a respective deflector can be designed to be non-rigid, such that it could collapse when subjected to a high air drag. Each deflector 15 . 1 , 15 . 2 . . . 15 . n may also be designed to be foldable and unfoldable. Hence, the deflector(s) 15 . 1 , 15 . 2 . . . 15 . n can be movable, such that they can be retracted, unfolded, tilted and/or displaced in any direction, by active control means or automatically due to the air drag.
[0032] According to another preferred embodiment, each air deflector 15 . 1 , 15 . 2 . . . 15 . n is fixed to the elongated body 8 , with a fixed inclined angle towards the flight direction F.
[0033] FIG. 3A shows an arrangement according to a further embodiment of the invention. According to this embodiment, at least two deflectors 15 . 1 , 15 . 2 . . . 15 . n are arranged in a row, along a first longitudinal side L 1 of the launch opening 10 . Consequently, the other opposite longitudinal side L 2 of the launch opening 10 is lacking any deflectors. By redirection of the air flow 13 of the deflectors, one air covering layer is created over the compartments 11 . 1 , 11 . 2 , . . . , 11 . n . Since only deflectors are arranged along one longitudinal side in a row, there is an advantage with respect to the total air resistance over other solutions having more deflectors that are not in a row.
[0034] In FIG. 3B is shown a yet another embodiment of the arrangement. According to this embodiment, at least two deflectors 15 . 1 , 15 . 2 . . . 15 . n are arranged in a row, along each longitudinal side L 1 , L 2 of the launch opening 10 . By redirection of the air flow of the deflectors, on the respective side of the launch opening 10 , two air covering layers can be created over the compartments 11 . 1 , 11 . 2 , . . . , 11 . n . A redirected air flow 13 from a deflector should not interfere with another redirected airflow 13 ′ from an opposite deflector.
[0035] As illustrated in FIG. 4 , showing a cross sectional view of FIG. 2 , lower picture, the deflectors 15 . 1 , 15 . 2 . . . 15 . n guide the air flow 13 in a direction over and above the compartments, such that one or more stable, laminar air covering layer(s) 16 , also called air boundary layer(s), are formed over the compartments 11 . 1 , 11 . 2 , . . . , 11 . n . Air flow caused by relative wind, due to the speed of the airplane, meets a front surface of a first deflector 15 . 1 and is redirected by the design of a front surface of the deflector 15 . 1 in a direction towards the compartments 11 . 1 , 11 . 2 , . . . , 11 . n , obliquely to the horizontal plane H and obliquely to the longitudinal direction L of the dispenser 2 (see FIG. 2 , lower picture). The redirection angle β of the air flow 13 in the horizontal plane by the first deflector 15 . 1 , i.e. the deflector positioned closest to the front end of the elongate body 8 as seen in the flight direction F, is in the range between 45° to 180°.
[0036] According to the above mentioned embodiments in FIG. 2 and FIG. 3B , the elongated body 8 is provided with at least two deflectors 15 . 1 , arranged in parallel and in pairs, one at each side of one opening 12 . 1 , 12 . 2 , . . . , 12 . n . In that respect, the deflectors on one longitudinal side, along a row, are preferably arranged at a first distance from the surface S 1 . The opposite deflectors of the other side of the launch opening 10 , along a row, are arranged at a second distance from the surface S 1 , apart from the first distance.
[0037] A first deflector 15 . 1 can be arranged adjacent and obliquely in front of the most forward opening 12 . 1 , on one or on each side of the opening 12 . 1 .
[0038] According to another embodiment, the elongated body 8 is provided with at least a pair of deflectors 15 . 1 , 15 . 2 , . . . 15 . n adjacent each opening 12 . 1 , 12 . 2 , . . . , 12 . n . In that respect, the deflectors are arranged such that one air flow that is directed by the first deflectors 15 . 1 , respectively, cross-wise over and across openings 12 . 1 , 12 . 2 , . . . , 12 . n of the compartments 11 . 1 , 11 . 2 , . . . , 11 . n , is not directed directly towards another deflector too not interfere with second deflectors 15 . 2 , of the compartments 11 . 1 , 11 . 2 , . . . , 11 . n.
[0039] The deflectors 15 . 1 , 15 . 2 , . . . 15 . n are preferably arranged such that the air covering layer 16 is created slightly above the compartments 11 . 1 , 11 . 2 , . . . , 11 . n , suitably above the surface S of the elongate body 8 , in order to eliminate any possible occurrence of a turbulent flow at the surface. This can be accomplished by arranging an air redirecting surface 18 of the deflector above the surface of the dispenser, as evident from FIG. 5A . The rear side R of the deflector can be provided with a protrusion P to redirect air flow that sticks and follows the back side of the deflector, such that this air flow is not directed over the compartments 11 . 1 , 11 . 2 . . . 11 . n where it can interfere with the created air covering layer 16 , which is shown in FIG. 5B .
[0040] The surface area, the width and the vertical extension, of each deflector facing the flight direction, are designed in order to reach the desired airflow boundary layer thickness over the compartments. The deflectors 15 . 1 , 15 . 2 , . . . 15 . n may be designed with various shapes such as convex, inclined surfaces, or the like.
[0041] As mentioned above, a redirected air flow should not interfere with another redirected airflow, since energy is lost due to a decreased air speed and any air covering layer could not be created, or alternatively would be poor. A redirected air flow from one longitudinal side should not interfere with a redirected air flow from the opposite longitudinal side. According to one embodiment of the present invention as evident from FIG. 5C , the problem has been overcome by arranging a first row of deflectors 15 . n 1 along one longitudinal side of the launch opening 10 at a first distance D 1 from the surface of the elongate body 8 . A second row of deflectors 15 . n 2 are arranged along another longitudinal side of the launch opening 10 at a second distance D 2 from the surface of the elongate body 8 . A redirected air flow from the first row of deflectors 15 . n 1 creates a first air covering layer L 1 . A redirected air flow from the second row of deflectors 15 . n 2 creates a second air covering layer L 2 . In that respect, the design is insensitive to different positions of the airplane in operation. It is possible to add further air covering layers by arranging additional deflectors such that an additional air covering layer is created. | An arrangement for storing and launching payloads. An elongate body includes at least one launch opening. The elongate body is configured to store the payloads in compartments. The compartments include openings. The arrangement is configured to be mounted on a vehicle with a longitudinal direction of the elongate body essentially coinciding with a direction of motion of the vehicle. The elongate body includes deflectors configured to act on an air stream and to permanently create an air covering layer across and over the compartment openings during use. | 5 |
This application is a continuation-in-part of application Ser. No. 752,609, filed Dec. 20, 1976, now U.S. Pat. No 4,104,508.
BACKGROUND OF THE INVENTION
This invention relates to apparatus and a method for supporting, without marring an article such as an opthalmic frame, which softens while being heated and which is subject to being marred while being heated.
The heating device this subject matter is concerned with, is radiant type heating or convectional hot air heating or both.
Particularly in radiant type heating are we concerned with the distance the object or article is from the radiation source. Since the temperature varies inversely to the square of the distance we want to be at a certain place relatively to the infrared generator so as not to be too cool or get too hot. Too close might mean scorching at a certain temperature setting of the machine while too far away would mean slower heating. Small variations in position when heating by convection makes little temperature difference and is not critical.
In radiant heating to keep the article close also means that physical contact with the heater parts is likely. This can mean heat dents, scratching and marring of the article, thus damaging it to some degree. The operator then tends to keep the article too far away or he sets the machine to a low setting thus taking longer to heat and at times underheating the article.
The present invention can accomplish the close positioning of the article to the radiator in the heater and at the same time eliminate any marring or damage to the article.
A prime object is to support a heat softened article while being exposed to heat without deformation or marring of its surface.
Another object is to provide tens of thousands of upwardly projecting but resilient filaments in carpet like arrangement which individually in supporting never press upwardly hard enough to impress their shape into the soft article and yet in their multitude effort are able to support the whole article.
Another important object is to provide a support which is transparent to infrared rays to allow their transmission past and through the support to the article.
Still another object is to take advantage of the phenomenon of fiber optics to transmit infrared rays to the article being supported through the carpet itself.
A further object is to provide a grid structure which allows free flow of air while serving as a support.
Another object is to support an article at a fixed distance from its radiant heat source to establish uniformity of heating of subsequent articles placed there, with the machine heating at a particular heat setting.
SUMMARY
This invention relates to carpet supports for articles composed of heat softening material whose surfaces are easily subject to deformation or other deleterious effects by reason of the weight of the article bearing down upon the supports when the article reaches its softening temperature. Fine filaments of glass fibers, vertically set, on end, in line with the direction of radiation and air flow serve to support an article set upon them. These pliant upstanding fibers in great multitude adapt to whatever conformity is needed to bear the object or article, each bearing upwardly with a pressure insufficient to indent its own form into the soft surface of the article while at the same time being greatly transparent to infrared rays but also transmitting the infrared rays from their bottom end to their top end, to the article by fiber optics effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan of an article heater showing a pair of eyeglass frames in dotted lines, being heated.
FIG. 2 is a front elevation of FIG. 1.
FIG. 3 is a vertical sectional view taken along line 3--3 in FIG. 1.
FIG. 4 is another vertical sectional view taken at 90° to FIG. 3 along line 4--4 in FIG. 1.
FIG. 5 is a greatly enlarged fragmentary section of the article support similar to FIG. 3.
FIG. 6 is a fragmentary vertical cross section of a modified form of the invention.
FIG. 7 is a vertical section of another modified form.
FIG. 8 is a plan view of a form jig.
FIG. 9 is a side elevation of FIG. 8.
FIG. 10 is a vertical section on line 10--10 of FIG. 8.
FIG. 11 is a vertical section of impregnated tapes.
FIG. 12 is another vertical section of a tape.
FIG. 13 is still another vertical section of a fused tape.
DETAILED DESCRIPTION
A heater housing 10 is shown in FIGS. 1 and 2 as having a flat top 11 provided with an opening 12 and is fastened upon a heater housing 13 by screws 14.
The housing contains regulated heating means 20 which may be electrical or otherwise, operable through a switch 21 to turn it on or off and controlled in temperature by a setting lever 22 rotable over a dial 23 to read the setting.
Legs 24 lift the housing 10 above the surface it is placed upon for entrance of air into the housing interior 25 through an opening (not shown) in its bottom 15. Air pressurizing means (not shown) is provided in the housing to cause an out flow of heated air past and through the heating means 20. The arrows 27 indicate this out flow of heated air as shown in FIG. 3 and 4 as well as the direction of infrared radiation, which may be supplied by the heating means 20. The heater and housing may be of hot air type shown in U.S. Pat. No. 2,789,200 or of the radiant type shown in U.S. Pat. No. 3,816,705.
A frame member 30 is held to the top 11 by screws 31 and has an opening 32 which is larger than the opening 12 in the top 11. This frame member 30 provides a holding means for a grid carpet generally indicated at 40.
The grid 40 is the foundation for the subject matter of this application and in this form comprises a glass fiber fabric 41 having the usual woof yarns 42 interwoven with the warp yarns 43. The lower portion as seen in FIG. 5 has the woof and warp yarns impregnated with a thermosetting or other suitable resin or cementitious binder 45 thus fixing this lower portion in a rigid monolithic structure. Another form of bonding the woof and warp yarns into a rigid monolithic structure is shown in FIG. 13, wherein the lower portion 460 is a homogenous mass of glass with the woof yarns 142 and warp yarns 143 fused to the lower portion 460. The upper warp yarns 43 are removed as seen in FIG. 5 to provide the woof yarns 42 with an individual freedom characteristic of the hairs of a tuft of a camel hair brush and is indicated as 46.
Since an individual glass fiber has an outside diameter of about 0.0005" (five ten thousandths of an inch) it has great tensile strength, resiliency, great softness and is a carrier of infrared radiation.
A successful carpet support illustrated and described herewith was made, starting with a two inch wide fiberglass tape doubled upon itself to be one inch wide. The warp yarns numbered eighteen to the inch while the woof yarns numbered thirty four to the inch. Each of the warp and woof strands were comprised of three twisted threads and each thread was comprised of approximately one hundred fifty continuous monofilaments, thus giving each strand about four hundred fifty individual fibers fiber ten thousandths of an inch in diameter.
After manufacture and assembly into the grid 40 the rigid bound portion equalled three eights of an inch high and the tuft portion equalled three eights of an inch, giving a total of three quarters of an inch finished height. In making such a carpet support the density or number of vertically disposed fibers per square inch determine its support capability, thus it can be designed for supporting heavier or lighter articles.
As seen in FIG. 1 this grid 40 is the form of many lateral bars 50 across the narrow span of the frame 30 and opening 12. These bars 50 meet and join at their ends to a perimeter band 51 totally surrounding all of the bar ends. A cross section through the perimeter band would look just like that in FIG. 5.
FIG. 3 shows the perimeter band 51 fitting inside the opening 32 of the frame member 30 while the bars 50 cross over and span the opening 12 in the top 11 of the housing 10. In FIG. 4 it is clearly seen how a lateral bar 50 spans across the opening 12. These bars 50 provide the rigid support necessary to carry an opthalmic frame F shown in dotted lines in FIG. 1 and FIG. 2.
The grid 40 is fitted into the opening 32 of the frame 30 in any suitable way, is possibly cemented in place or the frame 30 might be molded around and with the grid 40.
It will be seen in FIG. 1 that the frame assembly 30 with grid 40 with the bars 50 and perimeter 51 are held in place by the screws 31.
The manner in which the just described grid was made will now be described.
METHOD OF MANUFACTURE
In FIG. 8 can be seen a form jig 300 which essentially comprises a base 301 and a plurality of dowels or pegs 302. These dowels might be placed in various locations and spacing other than those shown to get many other contours or grid configurations.
Shown in FIGS. 8 and 10 are a tape 41 wound about the jig 300 in the following manner. Starting at 310 the tape 41 is wound downwardly and around the lowermost dowel 302a and up and around dowel 302b, then down to 302c around and up and down over the pegs 302 as the dotted, arrowed, lines 350 illustrate until the dowel 302d in the lower right hand corner is reached. The tape 41 is then wrapped up and around dowel 302e and then over to the left, around dowel 302b and down to 302a, then over to the right to dowel 302d and then up to 302e where it is fastened to hold its end in place.
In FIG. 8 the up and down lines 350 would represent the lateral bars 50 while the dotted lines 351 represent the perimeter band 51 previously described.
The windings may be made of tapes of heavy or light, double or single, whatever density is required to support these particular articles, the carpet is to be used for.
The completely wound tape 41 on the form 300 is now inverted and dipped, as shown in FIG. 10 into an impregnating and hardening liquid 345. Of course instead of being dipped the liquid 345 could be painted on. This liquid may be an epoxy resin, other thermosetting compound or other cementitious material which will impregnate the fibers to bind them together mechanically. This liquid may also be of a thermoplastic material such as a form of glass which when in a melted state, is a liquid. The form 300 with the wound and impregnated tape 41 is now removed from the liquid and the cement is allowed to harden or set. A rigid grid 40 has now been formed and it can be removed from the form 300 because it now is self supporting.
A cross section of a portion of the grid 40 is shown in FIG. 11 and would be typical of the locale of the section line 10--10 in FIG. 8. A section through the perimeter 51 and a looped portion of one of the bars 50 would look like FIG. 4, the loop portion now being joined to the perimeter 51 by the cement to make all of the runs 50 and 51 integral.
The lower edges 349, FIG. 11, of the grid 40 are next ground off and polished to form the optically receptive faces 47, shown in FIG. 5 and the upper ends of the woof strands 42 are cut at 348, FIG. 11, to form the upper terminal ends 46, in FIG. 5. These ends 46 may be trimmed flush with each other or may be cut to give a textured surface.
Upper warp strands 43 are now stripped off from their inter-weaving with the woof strands 43, down to the upper limit of the cemented and impregnated portion 45, FIG. 5.
Since the lower ends of all of the individual fibers are ground and polished they are now receptive to receiving of infrared radiation from the heating means 20 and will readily transmit these rays to their upper tips 46 contacting the article such as the frames F to deliver the energy rays to the article by the principles of fiber optics.
The arrows 60 in FIG. 6 indicate the entrance and exit of rays transmitted through the fibers 42 and 142.
A modified form of the invention is disclosed in FIG. 6 wherein the vertical fiber strands 142 are set on end and then have their lower ends impregnated with a suitable binding agent 145 such as an epoxy resin and with a slight change in procedure the just described steps of manufacture are used to make this form of the invention. Again a form jig 300 and a woven tape 41 are used. The tape 41 is wound on the jig as previously described to form the runs 350, 351 in FIG. 8 with the tape end then fastened in place. The extending edges 349 of the tape are cut at the selvage through the bends of the woof strands 142 at 449, FIG. 12. Several weaves of warp strands 143 are then stripped off to expose the woof strands 142 alone. This stripped portion is then impregnated with a hardening cement and left until hardened. Again an integral grid 40 has been made, the bars 50 being integral with the perimeter 51. The upper selvage bends of the woof strands 142 are now cut and the warp strands 143, see FIG. 12, that remain are removed to leave just woof strands 142 bound together at 145 and as shown in FIG. 6. The bottom 147 is then ground and polished and the top 146 may be trimmed or textured. Thus the warp strands 143 that are removed completely have served to position and hold the woof strands 142 in position until formed as described in the grid 40.
Another modified form is illustrated in FIG. 7 wherein the vertically disposed strands 242 are gripped in a channel member 245 which is then fabricated into a suitable grid.
The vertical sectional view FIG. 13 illustrates a grid carpet 40 manufactured in the same steps and order as previously described with the substitution of molten glass 460 in place of the liquid epoxy resin 345.
Upon dipping of the fiberglass tape 41 mounted on the form 300 into a puddle of molten glass 460, glass is picked up by capillary action of the woof strands 142 and the warp strands 143, all fusing together. After withdrawal from the puddle the glass 460 solidifies forming a rigid integrated homogenious bound portion 460. The molten glass 460 might have a slightly lower melting temperature than the glass fibers of the carpet 40 to assure a pick up of the molten glass 460 by the fibers.
An alternate manner to fuse the lower ends 449 of the tape 41 on the form 300 could be by application of heat or of a flame directed to lower ends 449 until fusing of the woof strands 142 and the warp strands 143 takes place, to thus form a grid carpet.
Carpets formed in this manner will withstand much higher temperatures than epoxy resin bound grids.
From the foregoing it can be realized that even with careless handling of an article on the carpet support, the article will not be marred. Also, that it is now possible to lay the article on the carpet while being heated instead of hand holding it and that the article will not be harmed even when softened. This carpet will also aid in heating the article since it is transparent to the infrared rays, even transmits the rays and allows for convectional air heating at the same time.
Also it has been demonstrated in what manner a carpet of this type and use can be easily and economically produced and varied in texture to be adapted to fit a product need.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in that use of such terms and expressions of excluding any equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible within the scope of the invention claimed. | A soft non marring carpet type support for articles while being heated into a softened condition consisting of either an intermittent or a continuous line of fine fiberglass fibers to accommodate either a flat or uneven surface in contact with the flexible tips, the support being so gentle and so distributed so as not to leave any impression on the articles softened surface. The support transmits a minimum of heat or cold by conduction, is transparent to infrared radiation across its thickness and also at the same time transmits infrared radiation through the length of its opticle fibers. | 3 |
TECHNICAL FIELD
[0001] The present disclosure relates generally to developing a system that uses raw machine data to classify operations of a machine, such as a bulldozer, loader, excavator, etc.
BACKGROUND
[0002] It is useful to know what operations a machine is performing for many reasons, including scheduling preventive maintenance, providing operator training, and suggesting supplemental equipment purchases, to name a few. However, short of asking an operator to specifically log every operation, which is impractical, machines used for construction, mining, logging, and others functions, do not report their activities, only the state of the machine.
[0003] U.S. Publication 2102041910 (the '910 publication) discloses a method of establishing a process decision support system that combines expert analysis and operational data to be determined if a given process is good or bad. The '910 publication fails to teach developing an operation classifier that determines a current operation of a machine based on expected operations of the machine and associated machine states.
SUMMARY
[0004] In an aspect of the disclosure, a method of developing a machine operation classifier includes i) identifying, via a user interface of a computer, an operation of a machine, ii) compiling, at the computer, a list of conditions that are associated with the operation of the machine, and repeating, at the computer, steps i and ii for one or more operations that the machine is expected to perform. The method may also include generating, via the computer, a classifier algorithm, wherein the classifier algorithm outputs the operation of the machine selected from the identified operations of the machine in response to identification of conditions in the associated list of conditions when the classifier algorithm is executed on a processor of the machine. The operation of the machine may includes the operation of one of a construction machine, a mining machine, or an earthmoving machine.
[0005] In another aspect of the disclosure, a method of creating an operation classification algorithm for a machine may include developing a catalog of operations performed by the machine, cataloging events associated with each of the operations, wherein the events include tool events, direction events, gear events, and load/power events and for each event, document one or more machine conditions associated with the event. The method may include, for each machine condition, developing a calculation used to determine the one or more conditions from one of a current machine state or a combination of current and previous machine states. The method may continue by generating a classification algorithm that monitors the one or more machine conditions and outputs a current operation of the machine using the one or more conditions to identity events associated with the operation.
[0006] In yet another aspect of the disclosure, a computer for creating a classification algorithm for a machine may include a processor, a user interface coupled to the processor, and a memory storing instructions for execution on the processor. When the instructions are executed on the processor, the computer may receive, via the user interface, information about the machine. The information may include a catalog of operations performed by the machine, one or more events associated with each of the operations, and information for determining when each of the one or more of events has occurred. Further instructions may be executed by the processor that cause the computer to generate the classification algorithm that determines when one or more events has occurred in the machine and matches the one or more events to an operation from the catalog of operations.
[0007] These and other benefits will become apparent from the specification, the drawings and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an illustration of a first off-road machine;
[0009] FIG. 2 is an illustration of a second off-road machine;
[0010] FIG. 3 is an illustration of a third off-road machine;
[0011] FIG. 4 is a block diagram of an exemplary controller for an off-road machine;
[0012] FIG. 5 is a block diagram of an exemplary computer adapted to generate machine operation classifier algorithms;
[0013] FIG. 6 illustrates an exemplary input chart for identification of events and operations; and
[0014] FIG. 7 is a flow chart of an exemplary method of generating machine operation classifier algorithms for a particular machine.
DESCRIPTION
[0015] A machine operation classifier observes characteristics of the operation of a machine and decides what operation is being performed. The classifier then logs the operations for later use in analyzing performance, operator training, maintenance scheduling, and more. However, the development of the operation classifier is complicated. Dozens of measurements are available from the machine, from direct measurements such as engine RPM and hydraulic cylinder pressures, to indirect measurements such as drawbar pull or tool position.
[0016] FIGS. 1-3 illustrate different machines with exemplary operations that each perform and some of the characteristics that may be observed to determine an operation.
[0017] FIG. 1 is an illustration of an off-road machine, specifically, an excavator 100 . The excavator 100 may have an engine 102 , tracks 104 or wheels for propulsion, and an implement 106 for use in performing a work function, in this case digging. The implement 106 may include a boom 108 and a boom cylinder 110 used to raise and lower the boom 108 . The implement 106 may also include a stick 112 that extends and retracts using a stick cylinder 114 and may further include a tool, such as a bucket 116 , the that rotates using a bucket cylinder 118 . In operation, the excavator 100 may use combinations of cylinder positions to engage the bucket 116 into a dig site to remove material and then to maneuver the bucket 116 to dump the material away from the dig site or into a dump truck or the like.
[0018] At a high level, the basic operations of the excavator 100 may include ‘travel’ using the tracks 104 , ‘dig,’ and ‘dump.’ At a lower level, the excavator 100 may also perform functions including boom raise and lower, stick reach and pull, as well as bucket rotate in and bucket rotate out. Each of these operations may be accomplished by one or a combination of events, including tool events, direction events, gear events, and power events. The identification of events may include “raw channel” information, such as tool commands, ground speed, gear settings, engine speed, fuel burn rate, or tool position. This raw channel information may be supplemented by “derived channel” information such as developing power (e.g. drawbar pull) using, for example, a gear setting and engine speed. Derived channel information may also be used when certain raw channel information is not available such as tool position. For example, tool position may be derived by integrating raw tool commands over time and incorporating upper and lower limits for tool position. That is, a boom up command can be integrated over time to follow movement of the boom. However, because the boom up command may be held beyond the time the boom 108 reaches its maximum height, a saturation limit must be applied so that the calculated position does not track beyond the actual position.
[0019] Information from the raw channel or derived channel data may be used to determine certain true/false events, such as whether the tool is active or inactive or whether a tool is engaged or disengaged. To determine if a particular operation is being carried out, several true/false events such as “stick extended=true” and “tool active =true” may be evaluated in combination.
[0020] Each event may have its own condition and tolerances. For example, to determine whether a tool active event is true or false a current tool command may be compared against a predetermined active value in view of a tolerance for the tool command.
[0021] Other events can be developed using information such as cylinder position for the various hydraulic cylinders, cylinder pressures can be used to determine whether a tool is loaded or unloaded, and groundspeed calculations using engine revolutions per minute (RPM) and corresponding transmission or torque converter settings may be used to determine power events. Other observable conditions may be associated with these true/false events such as change of engine RPM, change in hydraulic cylinder position, change in cylinder pressure, etc.
[0022] Exemplary operations and events are illustrated in Table 1 and Table 2 below.
[0023] For example, when the excavator 100 is performing a traveling operation the associated conditions may include: the boom 108 up, the stick 112 in, implement controls 107 neutral, and the transmission in a high gear, such as gear 3 or above. In another example, when the excavator 100 is performing a dig operation a more complex set of conditions may be evaluated to automatically determine the dig operation. Several true/false events may be defined for the operation. For example, “tool active =true,” “tool engaged =true,” and “high load/power =true” may be sufficient to infer that a dig operation is occurring. Negative events, such as “direction forward =false” may also be used to infer operations.
[0024] In order to define an event as being true or false, a value for a condition may be defined, with a given tolerance for the condition. The tolerance may provide for some hysteresis so that the state changes are damped and so that when alternate conditions, such as tool engaged and tool disengaged, are both true, the machine operation classifier algorithm may be able to infer that the machine is in a transition state. For example, a tool active event may be identified when the boom 108 may be down more than 20% from its fully up position with a 5% tolerance, the stick 112 may be out more than 40% from its fully in position with a 5% tolerance, and the bucket 116 may be rotated more than 40% from its fully in position with a 10% tolerance. Once some defined set of initial conditions are met, subsequent changes in conditions may be evaluated to see if the boom 108 is adjusted up or down (i.e., tool active), the stick 112 is drawn in, or the bucket 116 is rotated in, that is, using a derivative of respective cylinder positions. Hydraulic pressures for the stick cylinder 114 and the bucket cylinder 118 may be monitored to watch for pressure increases associated with engaging a work surface 119 .
[0025] Once instantaneous conditions for an operation are developed for a machine, such as the excavator 100 , a computer programmed for the special function of developing a classification algorithm may be operated to generate the classification algorithm for a particular machine that classifies operations of the machine by evaluating the instantaneous conditions or the time series of conditions associated with that operation. The computer program that generates the algorithm is discussed in more detail below. One goal of the process is to select the minimum set of conditions and/or events required to identify an operation.
[0026] FIG. 2 illustrates a grader 120 having a motor 122 , a steering wheel 124 , blade control 126 , a blade 130 , a blade angle cylinder 132 and a height cylinder 134 . The grader 120 may include steerable wheels 136 . The grader 120 is configured to scrape and level a worksite 138 using the blade 130 .
[0027] As with the excavator 100 above, the grader 120 may operate in several modes including a transport mode and a grading mode. The transport mode may be identified by conditions including groundspeed being above a certain threshold and the position of the height cylinder 134 being retracted beyond a threshold position. The grading mode may be identified by characteristics including blade position and drawbar pull, for example measured by strain gauges on the drawbar 140 .
[0028] FIG. 3 illustrates a wheel loader 150 with a motor 152 , operator control 154 , a boom 156 , boom cylinder 158 , and bucket 160 . The bucket 160 may be rotated between a load position and dump position via a bucket arm 162 and a corresponding bucket cylinder 164 .
[0029] Operations of the wheel loader 150 may include moving to a load point, loading, moving to a dump point, dumping and scraping. Each may be characterized by events associated with that operation. For example, loading may be characterized by lowering the boom 156 beyond a percentage of full height, such as 50 %, rotating the bucket 160 back within a percentage of fully up (or racked), such as 40 %, and being engaged in forward motion. When this action is followed by retracting the bucket 160 to fully up and raising the boom 156 , the load operation may be confirmed.
[0030] Dumping may also have a sequence of events that characterize the operation, such as raising the boom 156 and fully dumping the bucket 160 , either at once or in stages. The ability to measure the bucket load improves the ability to identify operations in that a bucket full of material is indicative of having completed a load operation and an empty bucket is indicative of having completed a dump operation. Bucket load may be directly determined from a raw condition of the loader 150 , such as a mass sensor (not depicted) on the boom 156 . Alternatively, the bucket load determination may use a derived condition from other measurements such as boom cylinder pressure and bucket cylinder pressure.
[0031] One scraping operation may involve fully lowering the bucket 160 and lowering the boom 156 so that the bottom edge of the bucket 160 is nearly vertical to the work surface and then moving backward to level the work surface. By recognizing these conditions, the scraping operation may be identified.
[0032] FIG. 4 illustrates a controller 200 that may be used in a machine, such as excavator 100 or any of the other machines discussed above, to execute a classification algorithm that identifies a machine operation based on observed conditions in the machine 100 . Controller 200 may include a processor 202 coupled to a memory 204 via a data bus 206 . Also connected to the data bus 206 may be a number of sensor inputs, that may include but is not limited to, a torque or drawbar pull sensor 208 , a groundspeed sensor 210 , a track speed sensor 212 , a slope sensor 214 , or a gear sensor 216 . Also connected to the data bus 206 may be outputs such as a driver to provide information to an operator display 218 or an interface 220 to provide log data to an local device, such as a memory card, or via a network connection (not depicted) to an external device.
[0033] The memory 204 may be any of a number of physical hardware memories including separately or in combination hard disk drive, a solid-state memory, flash memory, removable storage media, or the like, but does not include propagated media such as carrier waves. The memory 204 may include an operating system 222 and associated utilities 224 used, for example, for set up and diagnostics. The memory 204 may also include the classification algorithm 226 that is executed by the processor 202 to collect data from the various inputs and generate a log of operations. The classification algorithm 226 may include performance calculations 228 such as those discussed above to identify certain events based on characteristics of the machine 100 . The classification algorithm 226 may also include, among other routines, operating data and/or lookup tables 230 used to store available operations, events associated with each of the operations, and conditions associated with the various events.
[0034] FIG. 5 illustrates a computer 250 that may include a processor 252 and a memory 254 coupled by a data bus 256 . The computer 250 may include a variety of user interface elements including, but not limited to, a display or touch screen 258 , a keyboard and/or mouse 260 , a microphone 262 , a camera 264 , and speakers 266 . The computer 250 may also include a network interface 268 used to communicate via a local or wide area network (not depicted). As above, the memory 254 may be any of a number of physical hardware memories including separately or in combination hard disk drive, a solid-state memory, flash memory, removable storage media, or the like, but does not include propagated media such as carrier waves.
[0035] The memory 254 may include an operating system 272 and utilities 274 . The memory may also include an algorithm program 276 that receives input about operations of a machine as well as various events and associated conditions. The operation of the algorithm program 276 as discussed in more detail with respect to FIG. 6 . Briefly, while the algorithm program 276 is executed by the processor 252 various inputs are received including a catalog of operations 278 , a catalog of events 280 and their associated conditions, and a corresponding classification algorithm 282 is output in stored for use in a particular machine, such as machine 100 . The algorithm program 276 may be used to generate multiple classification algorithms for various machines as illustrated by a second operations catalog 284 , a second event catalog 286 , and a second classification algorithm 288 .
[0036] FIG. 6 illustrates an exemplary input chart 300 for identification of events and operations. The chart 300 illustrates how a user may interface with the algorithm program 276 to identify characteristics associated with various operations so that the algorithm can generate the code necessary to identify and log the operations of interest. The chart 300 shows exemplary data collected over time for a bulldozer displayed in vertically arranged set. Other data sets may be used depending on the piece of equipment and the exact operations being characterized.
[0037] FIG. 6 shows four representative data series: ground speed, power (i.e., drawbar pull), blade raise (i.e., blade tool active), and blade angle (i.e., blade angle active).
[0038] A user may create a drop down list of the possible operations/segments for the particular machine, in this case, Load, Carry, Spread, and Reverse. Other machines may have different lists of possible operations. Next, the user may select one of the operations in the drop down list to let the system know which operation logic will be created. The user may then specify whether the parameter that is being specified should be a minimum or a maximum. Finally, the user may move the cursor over one of the time series plots and sees a dynamic horizontal line, e.g., line 302 for ground speed, line 304 for power, line 306 for blade raise, and line 308 for blade position. Each line 302 , 304 , 306 , 308 may be separately selected and adjusted by dragging with a cursor. When the user has decided on the threshold value for a given channel, the user may click an input button to accept the location. The system may then record, for example, “Carry if PWR_alg>0.4” assuming minimum was previously selected. More interface options allow selection of “and” or “or” criteria to compose multiple logic conditions.
[0039] The user may also add labels 310 and 312 via the user interface that allow correlation of operations to the data series for ease of identification. Sample pseudo-code output associated with the completed process are shown below.
INDUSTRIAL APPLICABILITY
[0040] The ability to generate classification algorithms for various machines by capturing the operations the machine performs and events associated with each operation reduces the time and effort required to create classification algorithms and may also improve the quality of the classification algorithms by generating consistent code from a human readable set of inputs.
[0041] FIG. 7 is a flow chart of an exemplary method 330 of generating machine operation classified algorithms for a particular machine 100 . At block 332 an operation performed by the machine 100 may be identified. A list of exemplary operations is depicted in Table 1 below. For example, dig, carry, and spread are typical of bulldozer operations where the blade digs material, carries the material to a point at the worksite, and spreads the material at the new location.
[0042] At block 334 , events associated with the operation may be identified. The events may include tool events, direction events, gear events and load or power events. As discussed above, events may be true/false evaluations related to conditions in the machine 100 . At block 336 , for each event one or more conditions associated with that event may be identified. The condition may be defined as a function of raw data (see, e.g. Table 4 below) or may be a function of derived information, an example of which is shown in Table 3 below. Derived information may be calculated using one or more raw data elements.
[0043] At block 338 for each condition a calculation is developed that evaluates conditions in the machine for current and/or past machine conditions, whether raw or derived, and generates an output corresponding to the inferred operation being performed. In one embodiment, the calculation may be an actual calculation or may be a programmatic device such as case statements known in some programming languages.
[0044] For example, forward travel may be described in pseudo-code as
[0000]
blade_tool_active == 0
AND
PWR < 0.2 OR steer_avg > 0.2
AND
ground_speed_mps > 0
[0045] where PWR is drawbar pull, steer_avg is steering average displacement, and groundspeed is in meters per second.
[0046] Similarly, the load operation of a bulldozer may be expressed in pseudo-code as:
[0000]
ALWAYS (the following must always be true for the operation)
gear > 0 AND steer < 0.3 AND 0 < ground_speed_mps < 1.5
BEGIN IF (the following triggers the operation to start):
PWR_deriv > 0.02 OR eng_spd_deriv < −25
AND
PWR > 0.1 AND
blade_lower_flag > 0 AND
blade_tool_active == 1 AND
gear > 0 AND
steer_avg < 0.3
END IF (the following triggers the operation to stop)
PWR_deriv > 0.075
[0047] where steer is the steering angle and PWR_deriv is the first derivative of drawbar pull.
[0048] If additional operations are available to be included in the classification algorithm execution returned to block 332 and the process is repeated for the additional operation. If no more operations are to be included in the classification algorithm, execution may continue at block 340 where the classification algorithm 226 used for installation into the controller 200 of the machine 100 may be generated. The classification algorithm 226 may be stored in memory 254 of the computer 250 and transmitted to the machine 100 via the network interface 268 or may be transferred using a known removable memory, such as a flash drive.
[0049] Tables 1-4 illustrate representative values. The actual values for a particular machine may be less than shown or may have values not specifically illustrated here.
[0000]
TABLE 1
Operations
Idle
Travel
Reverse
Dig/Load
Carry/Haul
Dump/Spread
Compact
Grade
Ditch
[0000]
TABLE 2
Direction
Tool Events
Events
Gear Events
Load/Power Events
Tool Active
Forward
High Gear
Low Load/Power
Tool Inactive
Stopped
Low Gear
High Load/Power
Tool Engaged
Reverse
Forward Gear
High Fuel Burn
Tool Disengaged
Reverse Gear
Low Fuel Burn
Specific Tool
Neutral
Position
Tool High Pressure
Tool Low Pressure
Note:
Events are True or False
[0000]
TABLE 3
Derived
Integrated Tool Command Gives Tool/Cyl
Position
Derivative of Cylinder Position
Derivative of Motor Position
Frequency of Tool Command
Drawbar-Pull
Pull-Weight Ratio
Normalized Drawbar-Pull
Normalized Tool Command (−1 to 1)
Machine Power
Tool Force
[0000]
TABLE 4
Raw
Cylinder Position
Motor Position
Tool Position
Tool Positve Command
Tool Negative Command
Tool Signed Command
Fuel Burn Rate
Tool Pressure
Signed Ground Speed
Ground Speed
Engine Speed
Transmission Input Speed
Gear
Transmission Gear Ratios
Fixed Drivetrain Ratios
[0050] In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A process for developing machine classification systems includes using human experts to associate expected operations with various machine states including drawbar pull, tool position, tool commands, gear, and ground speed, among others, to create a classification system that can be used in a particular machine. The classification system operates in real time to infer operations such as dig, dump, travel, and push from machine state inputs and logs the operations for use in operational analysis and maintenance of the machine. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to the feeding of envelopes to a printing press, and more particularly to a novel method and envelope feeder which, although it is independent of the printing press, delivers envelopes to the printing press at a rate determined by the rate of operation of the printing press.
Envelope feeders of the prior art are characterized by a construction which requires positive coupling to the drive mechanism of the printing press in order to synchronize the rate of delivery of envelopes to the press to the rate of movement of envelopes through the press. This requires significant structural variations in the feeder to accommodate use with various types and models of printing presses of diverse manufacture. This requirement contributes to excessive cost of manufacture of the feeders and to excessive cost of print production due to the time required to couple and uncouple the feeder and printing press.
SUMMARY OF THE INVENTION
The method and envelope feeder of this invention operates to maintain a vertical stack of envelopes at the infeed end of a printing press for acceptance by the printing press by independent operation of the infeed mechanism of the press.
It is the principal objective of this invention to provide a method and apparatus which overcome the aforementioned disadvantages and limitations of prior envelope feeders and methods.
Another objective of this invention is the provision of an envelope feeder of the class described which assures the maintenance of a vertical stack of envelopes available to the infeed mechanism of a printing press.
A further objective of this invention is to provide an envelope feeder of the class described which produces a vertical stack of envelopes by building the stack from the bottom by underlapping each succeeding envelope to the stack, thereby enabling the envelopes in the stack to be infed to a printing press sequentially from the top of the stack.
Still another objective of this invention is to provide an envelope feeder of the class described which is usable with a wide range of types and models of printing presses.
A still further object of this invention is the provision of an envelope feeder of the class described which is of simplified construction for economical manufacture, maintenance and repair and is operable with precision to make envelopes available to a printing press in accordance with the speed of operation of the press.
The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an envelope feeder embodying the features of this invention.
FIG. 2 is a longitudinal sectional view taken on the line 2--2 in FIG. 1.
FIG. 3 is a fragmentary side elevation of the left hand portion of FIG. 1 as viewed from the bottom in FIG. 1 and showing a portable, vertically adjustable support for the envelope feeder.
FIG. 4 is a fragmentary sectional view taken on the line 4--4 in FIG. 1.
FIG. 5 is a fragmentary plan view of the envelope feed roll assembly, on an enlarged scale as compared with FIG. 1.
FIG. 6 is a fragmentary vertical elevation, on an enlarged scale, of a resilient support for the feed roll assembly.
FIG. 7 is a fragmentary side elevation of an adjustable envelope feed control associated with the driven feed roll assembly component of the envelope feeder, parts being broken away to disclose structural details.
FIG. 8 is a fragmentary vertical elevation, on an enlarged scale, of means for securing the hold down assembly in retracted position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The illustrated embodiment of an envelope feeder of this invention includes a frame formed of laterally spaced side walls 10 and 12 secured together by the horizontal base plate 14.
It is an important feature of this invention that the envelope feeder is completely separate from and independent of operation of a printing press with which it is to be associated. To this end, the frame is secured to a supporting yoke 16 (FIG. 3) carried at the upper end of a telescoping post 18 provided with a plurality of vertically spaced openings 20. The post 18 telescope within a cooperating hollow post 22 which is provided with a transverse opening for the reception of a connecting bolt 24 configured for removable reception through a selected one of the vertically spaced openings 20. It is by this means that the frame of the envelope feeder is adjusted vertically to conform to the elevated position of the envelope infeed mechanism of a printing press. The bottom end of the hollow post 22 is mounted on the support platform 26 which is rendered mobile by the underlying wheels 28 and rear pads 30 which are vertically adjustable by the nuts 32 on the threaded rods 34 to allow for uneven floor support.
The frame supports an electric drive motor 36 (FIG. 2) which is mounted upon a base 38 extending between the side walls 10 and 12 of the frame. The output shaft of the drive motor mounts an output sprocket 40 which is coupled through drive chain 42 to a sprocket 44 on the main power shaft 46. This shaft extends transversely between the side walls of the frame and is supported in end bearings for axial rotation.
The main power shaft mounts a support roll 48 for the rearward end of an envelope delivery conveyor belt 50 the forward end of which is supported by the front roll 52 mounted for rotation with idler shaft 54. This shaft also extends between the side walls 10 and 12 of the frame and is journaled in end bearings.
An envelope storage tray 56 is supported between the side walls of the frame adjacent the rearward end of the frame. In the preferred embodiment illustrated, the storage tray is mounted removably in the frame in a forwardly declining disposition, by means of the rearward support rod 58 and the forward stone-mounting shaft 60 described more fully hereinafter. A pair of laterally spaced arcuate hook members 62 (FIG. 7) on the forward portion of the underside of the tray engage the stone-mounting shaft 60, to secure the tray against upward and forward displacement. A stop bracket 64 (FIG. 2) on the bottom side of the storage tray is arranged to abut the forward side of the rearward support rod 58 prevent rearward displacement of the tray. The tray thus is secured in proper position relative to the conveyor belt 50.
Laterally spaced envelope guide rails 66 are secured in the storage tray for properly positioning a stack of envelopes E to be fed through the feeder. In the embodiment illustrated, the guide rails are mounted on the storage tray 56 for lateral adjustment to different spacings, whereby to accommodate a range of envelope sizes. For this purpose (FIGS. 1 and 4) a laterally elongated bar 68 extends downward from each guide rail into a laterally extending slot 70 in the tray, and a threaded stud 72 on the bar receives a nut 74 to engage the underside of the tray, to clamp the guide rails in desired position on the tray.
An envelope hold down wire 76 (FIG. 1) is mounted frictionally on one of the guide rails 66 in position to retractably overlie a stack of envelopes E on the tray to restrict their downward movement.
The stack of envelopes in the storage tray are fed one at a time to the conveyor belt 50 by means of a driven feed roll assembly. This assembly includes a front main feed roll 78 secured releasably to a drive shaft 80 by a set screw 82 (FIG. 5) extended through a lateral extension 84 on one end of the roll 78. The drive shaft 80 extends transversely of the frame and is journaled for rotation in support bearings on the frame side walls. One end of the shaft extends through an opening in the side wall 12 and mounts a gear 86 which couples with the gear 88 secured to the main shaft 46. Thus, the front feed roll 78 is coupled through the main shaft to the electric drive motor 36 for simultaneous rotation with the delivery conveyor 50.
Supported by the feed roll drive shaft 80 for pivotal movement relative thereto are a pair of laterally spaced side plates 90 on opposite sides of the front feed roll 78. These side plates extend rearwardly of the front feed roll and mount between them a middle feed roll 92 supported for rotation about a fixed hollow shaft 94 and secured releasably between the side plates by bolt 96 extended through the hollow shaft and provided with knurled nut 98 to facilitate hand turning.
A second pair of side plates 100 are joined at their forward ends pivotally to the rearward ends of the first pair of side plates 90 by the bolt 96 and nut 98. For this purpose the joined ends of the side plates are reduced in thickness and lapped, as illustrated, to maintain uniform the spacing between the pairs of side plates 90 and 100.
The side plates 100 support between them a rear fed roll 102 mounted for rotation about a shaft 104 secured between the side plates by screws 106.
The middle feed roll 92 is driven by a belt 108 which couples a sprocket 110 on the middle feed roll to a sprocket 112 on the front feed roll 78. Similarly, the rear feed roll 102 is driven by belt 114 which couples a sprocket 116 on the rear feed roll to a sprocket 118 on the middle feed roll 92.
It is to be noted that the assembly of middle feed roll 92 and rear feed roll 102 may be pivoted upward away from the storage tray to facilitate removal of the tray and also to facilitate the insertion of a stack of envelopes on the tray. Also, the rear reed roll 102 may be pivoted upward relative to the middle feed roll 92 by pivoting the rearward pair of side plates 100 about the axis of the bolt 96 and nut 98. The rear feed roll is secured in this upward position by frictionally clamping together the lapped ends of the side plates by tightening the nut 98. This elevated position of rear feed roll 102 is desirable when short envelopes are being fed to the conveyor 50 and when the stack of envelopes on the tray is thicker than usual.
The feed roll assembly also is supported resiliently by a spring 120 (FIG. 6) attached at one end to a bar 122 secured transversely between the side plates 90 by screws 124. The opposite end of the spring is attached to the lower end of a threaded rod 126 extended upward through an opening in a bar 128 secured transversely between the side walls 10 and 12 by screws. A knurled nut 130 on the upper end of the rod 126 serves to adjust the rod vertically to vary the tension of spring 120 and thus the resilient support of the feed roll assembly. It is by this means that the pressure of the feed rolls 92 and 102 on the tray 56 may be relieved when no more envelopes E are in the tray. This avoids undesirable wear of the feed rolls.
Associated with the front feed roll 78 is spacer means by which to adjust the spacing under the front feed roll through which to control the number of envelopes that may be moved forwardly at the same time. In the embodiment illustrated, the spacer means is provided in the form of a pinch stone 132 secured to the mounting shaft 62 previously mentioned. The shaft is journaled in end bearings between the side walls 10 and 12 of the frame. A worm wheel 134 on the shaft 62 meshes with a worm 136 secured to the lower end of a shaft 138 which is mounted for rotation in a support block 140. A control knob 142 at the upper end of the shaft 138 facilitates rotation of the latter.
It is to be noted particularly in FIG. 7 of the drawings that the pinch stone 132 is mounted eccentrically on the shaft 62, so that rotation of the shaft operates to move the surface of the pinch stone toward and away from the front feed roll 78 and thereby vary the spacing therebetween. An access slot 144 in the storage tray 56 registers with the pinch stone to accommodate the foregoing adjustment of the stone relative to the front feed roll.
In the preferred mode of operation of the envelope feeder, the pinch stone 132 is adjusted to restrict the spacing between it and the front feed roll 78 so as to allow only two envelopes E to move between them at the same time. Thus, upon energization of the drive motor 36 and consequent rotation of the delivery conveyor 50 and the feed roll assembly, the uppermost envelope in the storage tray is fed forward under the feed rolls and onto the delivery conveyor. The next underlying envelope also is moved forward with the overlying envelope, but when it engages the pinch stone the latter provides sufficient friction to resist slightly the forward movement of the engaging envelope, even though that envelope is being driven forwardly by the middle feed roll 92. It is by this means that the uppermost pair of envelopes are spaced apart longitudinally with the rearward end portion of the upper envelope overlapping the forward portion of the next succeeding envelope.
When the uppermost envelope passes forwardly of the front feed roll 78, the next succeeding envelope then becomes the uppermost envelope, and the third envelope in the stack is driven forwardly by the rear feed roll 102, becoming paired with the second envelope to pass through the space between the pinch stone 132 and the front feed roll 78. The foregoing sequence of operation is repeated to produce a continuously forwardly moving train of envelopes, with the trailing end of each preceding envelope overlapping the leading end of the next succeeding envelope.
The train of lapped envelopes are moved forwardly by operation of the delivery conveyor 50 the working stretch of which overlies the base plate 14 of the frame (FIG. 2). The train of envelopes on the delivery conveyor are held down against the conveyor by a hold down assembly. This assembly includes an elongated support bar 146 which is positioned above the delivery conveyor and extends longitudinally parallel thereto. The support bar mounts a rear carriage 148 which is adjustable along the bar and is secured in desired position by a set screw 150. The rear carriage pivotally mounts a pair of hold down arms 152 the lower ends of which support hold down rolls 154 arranged to bear upon the upper surfaces of envelopes moving forwardly on the delivery conveyor.
The support bar 146 also mounts a front carriage 156 which is adjustable along the bar and secured in desired position by set screw 158. The front carriage mounts an arm 160 which declines angularly forward therefrom and mounts pivotally at its lower end a roll-mounting bar 162. Mounted at the forward and rearward ends of the mounting bar 162 are a pair of transverse axles 164 each of which rotatably mounts a pair of hold down rolls 166. Like rolls 154, the rolls 166 also are arranged to bear downwardly upon the upper surfaces of envelopes moving forward on the delivery conveyor.
The above described hold down assembly is provided with resilient downward pressure for insuring continuous pressure contact with envelopes moving forward on the delivery conveyor. In the embodiment illustrated, this is provided by a transverse pressure bar 168 journaled for rotation in bearings mounted on the side walls 10 and 12 of the frame. The square cross section of the pressure bar is received in a notch 170 in the rearward end of the support bar 146 and is retained in the notch by means of the overlying removable clamp screw 172. A lever arm 174 is secured intermediate its end to the pressure bar 168, and its lower end secures one end of a spring 176. The opposite end of the spring is secured to the side wall 10 by means of an anchor screw 178.
The hold down assembly is adjustable between the operative position illustrated and an inoperative position elevated above the conveyor 50. This is afforded by a latch pin 180 (FIG. 8) which is mounted for movement in a bore 182 in the lever arm 174 between a latching position extending into an opening 184 in the side wall 10 when the lever arm and hold down assembly are rotated counterclockwise about the pressure bar 168, and an unlatching position retracted from the opening 184. A stop pin 186 in the lever arm 174 extends across the bore 182 and through a notch 188 in the latch pin 180 to limit movement of the latter between said latching and unlatching positions.
The front end of the frame base 14 constitutes an envelope delivery end and is adapted to be positioned adjacent the infeed of a printing press P. This envelope delivery end of the frame forms an envelope stacking station which is defined by a pair of laterally spaced stack guides 190. These guides are mounted upon hangers 192 which are supported on a transverse rod 194 extending between the side walls 10 and 12 of the frame. Set screws 196 in the top ends of the hangers releasably engage the support rod 194 to secure the guides 190 in desired lateral spacing, to accommodate between them a stack of envelopes E of desired size.
As the envelopes are delivered forwardly to the stacking station, the forward ends of the envelopes are brought into abutment with a stop 198. Although this stop is illustrated in the drawings as being supported by the printing press, it will be understood that the stop may alternatively be mounted on the frame of the envelope feeder.
It is to be noted that as the envelopes are delivered forwardly to the stacking station between the guides 190, they move forwardly over a pair of laterally spaced wedge shaped elevating members 200 positioned adjacent the rearward end of the stacking station on opposite sides of the delivery conveyor 44. In the preferred embodiment, these wedge shaped members are each provided with a threaded stud 202 which extends downwardly through a longitudinally elongated slot 204 in the base plate 14 for adjustment along the slot. A nut 206 on the threaded stud under the base plate serves to releasably secure the wedge 200 in adjusted position. A plurality of pairs of slots spaced apart laterally on opposite sides of the conveyor 50 at different spacings accommodate lateral adjustment of the pair of wedges for envelopes of various widths.
Alternatively, the wedge shaped members may be formed from or include therein a piece of permanent magnet. Thus, by making the base plate 14 of the frame of magnetically susceptible material, such as steel, the wedge members may be secured to the base plate magnetically in any of a variety of positions to accommodate envelopes of different sizes.
The wedge members are positioned on the base plate so that when the envelopes in the stacking station are in abutment with the stop 198, the trailing and portion of the bottommost envelope projects rearwardly of the wedge members 200 and a spaced distance above the base plate 14. This elevated position of the trailing end of the bottommost envelope in the stacking station allows the next succeeding envelope to underlap the bottommost envelope in the stack. The stack of envelopes thus is built up from the bottom.
This elevated position of the rearward portion of the bottommost envelope in the stack also insures that the next succeeding envelope will properly underlap the bottommost envelope in the stack, even though there may have been an interruption in the progression of envelopes from the storage tray. That is to say, if all of the envelopes in the train of envelopes are properly overlapped as illustrated in the drawings, then each succeeding envelope will automatically enter the stacking station under the next preceding envelope. However, if an interruption in the train of envelopes occurs so that there is a gap between a leading envelope and the next trailing envelope, then the trailing envelope might jam against the leading envelope unless the trailing end of the leading envelope is elevated by the wedge members 200, to provide a space thereunder for entrance of the next succeeding envelope. The wedge members provide this spacing to insure that the envelopes are delivered to the stacking station in properly underlapped condition.
It is another important feature of this invention that a supply of envelopes be made available to the envelope infeed mechanism of a printing press P at all times even though the envelope feeder is not synchronized to the operation of the printing press, in the manner required heretofore. This is achieved in the present invention by maintaining in the stacking station a plurality of vertically stacked envelopes sufficient to supply the operational speed of the printing press. This is achieved by insuring that the delivery of envelopes from the storage tray to the stacking station exceeds the rate of processing of the envelopes through the printing press.
In the embodiment illustrated, an electric stacker switch 208 is mounted on the frame adjacent the stacking station. An electrical conductor cable 210 connects the switch in the electric circuit of the electric drive motor 36 to control the operation of the latter. The switch is provided with an elongated actuator feeler arm 212 which overlies the stacking station in position to intercept and thus be contacted by the uppermost envelope in a stack of envelopes in the stacking station. The switch is carried by an elongated support rod 214 which extends laterally across the top of the frame wall 10. A mounting block 216 is supported on the upper edge of the frame wall 10 for adjustment along the latter. A set screw 218 in the mounting block is arranged for releasable engagement with the frame side wall 10 to secure the mounting block in desired position of adjustment. A second set screw 220 in the mounting block is arranged to releasably engage the support rod 214 to secure the latter in desired position of lateral adjustment relative to the mounting block and also rotational adjustment relative to the mounting block. It is by this means that the horizontal and vertical positions of the switch feeler arm 212 may be adjusted to 50 and feed rolls thus are once again returned to operation to resume delivery of envelopes from the storage tray to the stacking station.
Since the delivery of envelopes from the storage tray to the stacking station exceeds the rate at which the envelopes are removed from the stacking station to the printing press, the foregoing sequence of starting and stopping the drive motor continues intermittently, always insuring an adequate supply of envelopes at the stacking station to meet the requirements of the printing press.
It will be apparent to those skilled in the art that various changes may be made in the size, shape, type, number and arrangement of parts described hereinbefore without departing from the spirit of this invention and the scope of the appended claims. | A vertical stack of envelopes is produced adjacent the infeed end of a printing press, for removal one at a time by envelope infeed mechanism of the printing press, the stack being maintained by adding envelopes one at a time to the bottom end of the stack when the height of the stack or number of envelopes in the stack is reduced to a predetermined magnitude, the rear end of the stack being elevated to facilitate insertion of added envelopes to the bottom of the stack. The envelopes are removed one at a time by operation of the envelope infeed mechanism of the printing press. The addition of envelopes to the stack is stopped when the height of the stack or number of envelopes in the stack is increased to a predetermined magnitude. | 1 |
TECHNICAL FIELD
The present invention relates to pulsation attenuators of the type utilized to smooth the operation of a refrigerant compressor and, more particularly, to an attenuator for dampening pressure and sound energy pulses in a piston-type compressor commonly used in a vehicle air conditioning system.
BACKGROUND OF THE INVENTION
A variety of refrigerant compressors for use in vehicle air conditioning systems are currently available. Two of the more popular vehicle compressor designs are the variable capacity axial type and the radial type, both of which use a series of pistons operating in an array of cylinders to compress the refrigerant gas.
In a wobble plate axial type compressor, the cylinders are equally, angularly spaced about and equally radially spaced from the axis of a central drive shaft. A piston is mounted for reciprocal sliding motion in each of the cylinders. Each piston is connected to a non-rotary swash plate or wobble plate received about and operatively connected to the drive shaft through a rotary drive plate.
During operation of the compressor, rotation of the drive shaft and drive plate imparts a wave-like reciprocating motion to the wobble plate. This driving of the wobble plate in a nutating path serves to impart a linear reciprocating motion to the pistons. By varying the angle of the wobble plate and drive plate relative to the drive shaft, the displacement or capacity of the compressor may be varied to effect the desired level of compressing action. The discharge from the cylinders is mixed in a discharge chamber in the housing, and to some extent pressure/sound energy pulsations are attenuated by the mixing action. An axial compressor of this type is disclosed in, for example, U.S. Pat. No. 4,428,718 to Skinner, entitled "Variable Displacement Compressor Control Valve Arrangement", issued Jan. 31, 1984, and assigned to the assignee of the present invention.
In a radial type compressor, a cylinder block is provided having an array of radially arranged cylinders. Each cylinder defines a piston receiving bore that is closed by a discharge valve assembly. A piston is positioned for reciprocation in each bore and driven by a crank shaft operatively connected to the engine of the vehicle. This compressor includes an annular discharge chamber defined between the periphery of the cylinder block and an outer cylindrical shell, which also tends to smooth out the inherent pulsations.
The radial type compressor is relatively compact and lightweight when compared to the wobble plate axial type compressor. This is because the radially extending pistons allow the compressor to be made with a minimal axial length. Accordingly, the compressor housing may be both smaller in size and lighter in weight. This makes the radial compressor particularly suited for utilization in compact vehicles. A radial compressor of the type described is disclosed in, for example, U.S. patent application Ser. No. 07/751,370 filed Aug. 28, 1991, entitled "Radial Compressor with Discharge Chamber Dams" and assigned to the assignee of the present invention.
While these piston type compressors provide a very effective way to compress and circulate the refrigerant fluid in a vehicle air conditioning system, an adverse side effect concerns delivery of the compressed gas in high pressure and noisy pulsations coincident with the discharge strokes of the pistons, rather than in a reasonably constant pressure and quiet condition. This shortcoming has to some extent been alleviated by the mixing chamber concept, but it has not been entirely solved. In addition to creating a rougher and noisier operating system, these discharge energy pulsations tend to lead to premature fatigue and failure of component parts throughout the air conditioning system, thereby diminishing its reliability.
Various attempts, other than providing mixing chambers, have been made to further reduce the effect of these energy pulsations in order to provide the desired smoother, quieter and more reliable compressor. One of the more successful approaches to date is disclosed in pending U.S. patent application Ser. No. 07/787,180 filed Nov. 4, 1991, entitled "Variable Discharge Flow Attenuation for Compressor" and assigned to the assignee of the present invention. In this approach, a rotary valve is positioned adjacent the discharge port of the discharge chamber in a wobble plate axial type compressor. This valve alternately covers and uncovers the discharge port of the compressor. The spaced variable flow orifices of the valve serve to attenuate the pulsations that occur during the operating cycle. Each flow orifice is preferably pear-shaped, and positioned with the necessary circumferential spacing for synchronization with the pumping stroke of the pistons within the compressor cylinders.
While the disclosed rotary valve is particularly effective in further attenuating pressure pulsations and thereby smoothing the operation and extending the service life of the compressor, this approach has a shortcoming. It is only readily integratable into a compressor of the axial type. Relatively extensive modifications are needed in a compressor of radial design in order to effectively utilize this concept.
Additionally, it must be noted that the already oversized axial-type compressor must actually be further enlarged to accommodate the rotary valve and the special nozzles that form the porting required. Accordingly, space limitations in a vehicle could even prevent the incorporation of an axial-type compressor modified to include this attenuator. Further, it should be noted that the rotary valve concept is not able to be easily retrofitted to previously designed and manufactured compressors. Similarly, the spaced dam attenuation concept in the discharge chamber of a radial compressor, described and claimed in the prior application Ser. No. 07/751,370 referenced above, is generally limited to incorporation in new radial compressors. Also, sound energy attenuation is limited since metal components are required. In view of this, it should be appreciated that a need exists for an alternative approach to provide attenuation of pressure/ sound energy pulses of the refrigerant gas being discharged from the compressor of a vehicle air conditioning system.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide an apparatus of relatively simple and inexpensive design for pressure/sound energy pulse attenuation that is substantially universal in its application and may be incorporated into piston-type compressors of new designs, or retrofitted into old designs.
It is another and related objective to provide an attenuator that can be easily installed by a simple connection into the discharge line adjacent the discharge port of any piston-type compressor, in order to provide efficient primary or secondary attenuation of pressure/sound energy pulsations.
Another object of the present invention is to provide an apparatus that more efficiently attenuates energy pulsations so as to achieve smoother, quieter operation and a longer air conditioning system service life. Accordingly, customer satisfaction is significantly enhanced.
Still another object of the present invention is to provide an apparatus for attenuating energy pulsations in the refrigerant gas being discharged from the discharge chamber of a piston-type compressor wherein a variable geometry profile is provided to the flow passage by a series of hydraulically or pneumatically formed dampening chambers. The constantly changing chambers function to modulate pressure and reduce sound energy peaks in the passage and thereby progressively flatten or deaden the same.
Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved pressure/sound energy pulsation attenuator is provided for use with a piston-type compressor of substantially any design. The apparatus includes an elastomeric body in the form of an elongated tube. This body is separated by annular dividers forming the chambers that are filled with damping fluid. Either liquid or pressurized gas is selected depending upon the operating characteristics, including the compressibility factor required to provide optimum damping performance for the particular compressor in question. The fluid-filled chambers are concentrically disposed about and define a sectionalized flow passage for the refrigerant gas.
As described in detail below, the attenuator is preferably mounted in the discharge line adjacent the discharge port of the compressor. In accordance with the present invention, reliable passive damping and smoothing of the pressure pulses and reducing the sound energy level is provided. This is accomplished through the provision of what is effectively a constantly changing flow passage that absorbs the pressure/sound pulsations to maintain a more constant and quieter downstream refrigerant gas flow in the discharge line. The chambers are positioned in series and the sections of flow passage are separated by central flow orifices of a constant area in the annular dividers. Together the sections/orifices serve to generate counteracting flow oscillations that propagate in a wave-like manner to efficiently cancel some of the absorbed peak energy, and thereby smooth the operation of the air conditioning system.
In the preferred embodiment, the annular dividers partition the fluid-filled body into three individual chambers and three passage sections. An array of damping tracks extending through the dividers provide fluid communication between the chambers. Preferably, the damping tracks restrict the fluid flow and enhance the damping effect of the constantly changing passage profile generated by the fluid chambers.
During compressor operation, the pressure/sound energy pulses of the refrigerant gas being discharged from the compressor normally fluctuate during a single operational cycle in a predictable and periodic fashion. More particularly, each pressure pulse is at a maximum or peak at the completion of each discharge stroke, and at a minimum between each discharge stroke. Upon reaching the first section of the flow passage of the attenuation apparatus of the present invention, each pulse at its peak strikes and momentarily compresses the internally bulging wall of the elastomeric body associated with the first in-line chamber. Accordingly, some damping fluid within the first chamber is forced through the damping track in the adjacent divider, and enters the second chamber, causing that chamber to expand. By positioning the fluid filled body within a rigid tubular housing that forms the exterior wall of the body, the resulting expansion in the chamber is forced inwardly. In passing through the damping tracks, some of the peak energy is absorbed and released as heat, so that vibration and noise is attenuated.
However, conservation of the energy of the pressurized gas is desirable, so that fluid pressure energy transfer, rather than energy loss, is important. This occurs in the downstream or second section of the passage that is now constricted. Preferably, at peak expansion, the cross-sectional area of the flow passage is closed by approximately 50%. For example, in a typical attenuator, the flow passage defined by the inward expansion of the second in-line chamber is reduced from substantially 0.5 square inch to 0.25 square inch. This constriction serves to retard and counteract the peak flow of refrigerant gas as it arrives in this downstream section of the passage, thus filling in the trough or valley in the pressure cycle.
Also, sound energy waves are absorbed by the elastomeric walls. The residual pressure/sound energy pulses bounce off the curved walls at random angles causing a high incidence of cancellation by interference from oppositely directed pulsations. In effect, this multifaceted action causes a substantial flattening or smoothing of the high energy pulses.
As the passage defined by the second in-line chamber restricts the flow, the refrigerant gas tends to push back against the interior wall of the second chamber, thus causing a compression of that chamber. This causes damping liquid within the second chamber to flow from the second chamber in opposite directions through the damping tracks in the dividers into both the first and third chambers. This results in the further modulation by absorption and transfer of additional energy of the pulsing flow. The expansion of the first and third dampening chambers squeezes the gas in between tending to force more mixing of the gas molecules of the high and low pressure segments, further adding to the smoothing action.
As the now significantly reduced pulse continues to move downstream, it must pass through the third in-line passage section, now formed by the expanded interior wall of the third chamber. As a result of the lowered pressure and deadened sound energy pulses striking and pressing against the bulging wall, the final dissipation of energy takes place. There is flow back through the damping tracks in the second annular divider, pressure and sound wave cancellation by intermixing and interference action and sound energy absorption by the elastomeric walls, thus resulting in nearly complete attenuation of the pulsation energy at this point. The first chamber is now ready to effectively begin attenuation of the next refrigerant gas discharge pulse, and the attenuation cycle repeats itself.
It should be appreciated that the discharge pulses occur at set intervals with the discharge of each piston from the compressor, and the spacing between the dividers is tuned to provide the best damping action. It is expected that in any given compressor, a predictable rhythm can be established by tuning that propagates a highly efficient wave-like motion for maximum attenuation, but with minimum refrigerant gas pressure energy loss. This occurs as the gas passes through the constantly changing profile passage defined by the series of first, second and third fluid-filled chambers.
As the damping fluid flows through the damping tracks back and forth to the adjoining chambers, a high dynamic rate dampening takes place and ideally serves to modulate the undesirable peaks of pressure energy. The fixed diameter flow orifices of the dividers help to produce the reverberating sound waves in the gas flow that tend to cancel each other and dissipate some of the sound energy. Each flow orifice of the dividers is preferably substantially equal to the cross-sectional area of the refrigerant gas discharge line. Accordingly, no unyielding restriction is provided relative to the discharge line that could cause back pressure and degrade compressor efficiency and performance. The orifices are lined with the molded elastomeric walls of the chambers to maximize the energy attenuation from the refrigerant gas pulsations without causing significant blocking action.
Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWING
The accompanying drawing incorporated in and forming a part of the specification, illustrates several aspects of the present invention and together with the description serves to explain the principles of the invention. In the drawing:
FIG. 1 is a longitudinal cross-sectional view of the apparatus of the present invention showing the in-line chambers forming a flow passage to attenuate gas pulses from the compressor of a vehicle air conditioning system;
FIG. 2 is a cross-sectional view along line 2--2 of FIG. 1;
FIG. 3a is a cross-sectional view of the apparatus of the present invention showing a refrigerant gas pressure pulse being received in the first section of the flow passage and sound energy pulses in the second section;
FIG. 3b is a view similar to FIG. 3a showing that pressure pulse positioned in the downstream or second section of the flow passage defined by the second chamber and sound energy pulses reflected to the first and third sections; and
FIG. 3c is a view similar to FIGS. 3a and 3b showing the pressure pulse now dissipated in the flow passage formed by the third chamber, the sound energy pulses also now dissipated, and a second pressure pulse just entering the flow passage and defining the start of the next operational cycle.
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing.
DETAILED DESCRIPTION OF THE INVENTION
Reference is now made to FIGS. 1 and 2 showing the attenuator 10 of the present invention for attenuating pressure/sound pulsations such as are commonly produced in refrigerant gas discharged from a piston-type compressor of a vehicle air conditioning system. As shown, the attenuator 10 is positioned in a discharge line L adjacent the discharge port of the compressor (not shown) that leads to the other components of the vehicle air conditioning system.
The attenuator 10 includes an elastomeric body 12. The body 12 may be produced in any appropriate manner from an elastomeric material, such as forming polychloroneoprene or NBR about an appropriately shaped mandrel. The elastomeric body 12 is generally annular and tubular in shape, and includes a sealed cavity filled with a damping fluid. Any known damping fluid may be utilized. This includes either a liquid or a gas. The fluid selected is a function of the required compressibility and other physical properties to provide the desired damping action. If a liquid is utilized, a common anti-freeze mixture is selected.
The body 12 also includes a central flow passage 14 for the refrigerant gas that extends along the longitudinal axis thereof. This passage 14 is connected in fluid communication with the discharge line L and defines the refrigerant gas flow path. The direction of flow of the refrigerant gas is shown by action arrows A.
As further shown in FIG. 1, the body 12 is molded to or adhesively connected to a pair of spaced, annular dividers formed from a rigid material, such as a suitable aluminum or other metal alloy. The dividers 16 are spaced so as to partition the cavity C into three chambers 18, 20, 22. These chambers 18, 20, 22 are serially aligned along and concentrically disposed about the refrigerant gas flow passage 14 so as to progressively attenuate pressure pulsations, in a manner described above and in greater detail below.
As also shown in FIGS. 1 and 2, an array of damping tracks 24 extend through the dividers 16. The damping tracks 24 provide fluid communication between the second chamber 20, and the first chamber 18 and the third chamber 22. Accordingly, as described in greater detail below, when one of the chambers 18, 20, 22 is compressed, damping fluid is forced from that chamber through the damping tracks 24 into the adjoining chamber or chambers. This causes the adjoining chamber(s) to expand. Since the elastomeric body 12 is confined within a rigid tubular housing or sleeve 25 (which is also preferably a metal alloy), the expansion is forced to assume an inward direction. Accordingly the inner annular wall of the expanded chamber(s) of the body 12 partially closes, and the corresponding section of the refrigerant gas flow passage 14 is constricted.
Operation of the apparatus 10 of the present invention will now be described in detail with reference to FIGS. 3a-3c.
As shown in FIG. 3a, as a first peak pressure pulsation P1 moves through the discharge line L into the first section of the passage 14, yieldingly restricted by the first or inlet chamber 18, an outwardly directed force is exerted (note pressure action arrows) that causes said first chamber to compress. As this compression occurs, some pressure energy from the pulsation P1 is absorbed in the bulging walls of the elastomeric body 12 and the damping fluid. The compression of the chamber 18 also results in some damping fluid being forced through the damping tracks 24 formed in the outer margins of the first in-line divider 16; i.e. fluid flows from the first chamber 18 into the second or downstream chamber 20 (see flow action arrows B). In order to accommodate the additional damping fluid received from the first chamber 18, the second chamber 20 expands inwardly constricting the refrigerant gas flow passage 14. As shown in the figure, the passage 14 is actually restricted approximately 50%. In a preferred embodiment for a conventional compressor of the type described, this can be from a cross-sectional area of one-half square inch to a cross-sectional area of one-fourth square inch at its points of maximum expansion. Simultaneously with the pressure pulse attenuation, sound energy pulses S 1 and S 2 are partially absorbed and reflected, as shown by the dashed line arrows.
Following the refrigerant gas pulsation P1 as it flows through the passage 14, it now passes from the first chamber into the area of the second chamber (see FIG. 3b) through flow orifice 26. Preferably, the cross-sectional area of the orifice 26 is substantially the same as the cross-sectional area of the discharge line L. Accordingly, there is no unyielding restriction of refrigerant gas flow. By avoiding the provision of an unyielding restriction, any significant build-up in back pressure of the refrigerant gas is avoided, and the desired operating efficiency of the compressor is maintained.
In the second section of the passage 14, the pulsation P1 engages the inwardly expanded wall of the second chamber 20, thereby further retarding the peak flow of the refrigerant gas. Further, the pulsation P1 exerts an outwardly directed force against the yielding inner wall of the second chamber 20 causing the chamber to begin compressing (note pressure action arrows). As the second chamber 20 compresses, some additional energy from the pulsation P1 is absorbed and damping fluid is forced through the damping tracks 24 in both the dividers 16 into the first or inlet chamber 18 and third or outlet chamber 22 (see flow action arrows C). As the damping fluid flows through the tracks 24, significant dissipation of the pulsation energy occurs.
Of course, the chambers 18, 22 are simultaneously caused to expand inwardly in order to accommodate the flow of damping fluid. As a result, the pulsation P1 in this second section of the passage 14 is squeezed to promote mixing and swirling of the high pressure and low pressure segments of the flow that smooths the pulsation energy without significant energy loss. At the same time, the sound energy pulses S 1 , S 2 undergo further attenuation. More particularly, some of the sound energy is absorbed by the inwardly expanding elastomeric walls of the first and third chambers 18, 22. Further, the residual energy of the pulses S 1 , S 2 is reflected from these curved walls at random angles (note dashed line arrows). This causes a high incidence of collisions between the sound energy pulses and thus, cancellation by interference of oppositely directed pulses. Accordingly, a further substantial flattening or smoothing is achieved.
Next, the pulsation P1 passes through the flow orifice 26 of the second divider 16 and enters the third section of the passage 14 restricted by the bulging annular wall of the third chamber 22 (see FIG. 3c). There, the already significantly attenuated pressure pulsation P1 and sound wave pulses S 1 , S 2 are again attenuated, and substantially all of the residual pulsation energy is now dampened to minimize noise and smooth compressor operation. More particularly, the final stage of the pressure and sound wave attenuation and cancellation takes place by flow of fluid through the tracks 24 (note flow action arrows D) and intermixing and interference action, as well as sound energy absorption by the elastomeric walls. At about the same time, another pressure pulsation P 2 and attendant sound wave pulses are entering the first section of the flow passage 14, and the beneficial attenuation process repeats itself. As indicated above, this description provides the best understanding of the various damping forces and actions as understood at the present time. There are variations expected dependent on the many parameters of the particular compressor and refrigerant flow involved, and the tuning of the attenuator 10 to best accommodate the same. However, the basic structure and operation, as set forth in the claims, remain the same.
In summary, numerous benefits result from employing the concepts of the present invention. The attenuator 10 provides serially aligned damping chambers 18, 20, 22 that are concentrically disposed about the refrigerant gas flow passage 14. Pressure and sound wave pulsations P 1 , P 2 , S 1 , S 2 are effectively dampened so as to not only smooth, but quiet the operation of the air conditioning system. The in-line flow sections defined by the chambers 18, 20, 22 and the connecting flow orifices 26 function to propagate a reverberating wave pattern that adds significantly to the smoothing action. As will be realized, this is advantageously done in a passive system requiring no monitoring, and no mechanical or electrical controls. Additionally, it should be appreciated that the attenuator 10 is relatively inexpensive to fabricate and, advantageously, simple to install. It may also be retrofitted onto vehicles and provides a relatively simple and inexpensive means for smoothing compressor operation and suppressing noise, as either a primary or secondary attenuator.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as is suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with breadth to which they are fairly, legally and equitably entitled. | An attenuator for pressure and sound energy pulsations, such as are commonly produced in refrigerant gas discharged from a piston-type refrigerant compressor, is provided. The attenuator includes an annular elastomeric body supported by a rigid tubular housing. The body forms a cavity filled with a damping fluid and annular dividers define multiple chambers that are concentrically disposed about a central refrigerant gas flow passage. Damping tracks are provided in the dividers to allow fluid flow between the chambers. As refrigerant gas flows through the passage, the pressure/sound pulsations are flattened and smoothed. The resilient walls of the body are designed to bulge inwardly for a maximum 50% restriction. Gas flow orifices of the dividers have substantially the same cross-sectional area as the refrigerant line. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and apparatus for applying to the skin, in a controlled manner, a radio frequency generated plasma in order to heat and selectively damage thin superficial layers of the skin, thereby inducing a renewal process of the epidermis.
[0003] 2. Description of the Related Art
[0004] It is well known in the skin treatment art that in order to renew the epidermis layer, induced damage of the skin is required. One such method uses laser radiation that is incident on the skin and that generates several effects on the skin, depending on the wavelength of the laser radiation, the pulse duration of the laser energy applied to the skin, and the radiation energy provided to the skin.
[0005] The most commonly used method is CO 2 laser radiation for generating a superficial heating of the skin. When laser light reaches the skin, its intensity decreases exponentially as it progresses down into lower layers of the skin. This means that the thermal energy that is delivered is higher in the first layer and decreases exponentially as its progresses down to lower layers of the skin. Moreover, the first corneum stratus of the skin has a higher absorption than other layers. Such an energy profile is not suitable for a uniform heating of a volume of skin due to the fact that in the superficial (upper) layers, the reached temperature is too high and in the lower layers the reached temperature is not high enough to trigger the desired skin treatment process.
SUMMARY OF THE INVENTION
[0006] The present invention utilizes a method and apparatus of heating a superficial portion of skin using a combined action of radio frequency and a plasma generated by the same radio frequency.
[0007] Two principles are used in the present invention. First, radio frequency currents are localized in the external layer of the skin due to the skin effect, and thus the heating is localized in a thin (upper) layer of skin.
[0008] It is well known that an alternating voltage applied to a conductor generates a current on the external layer of the conductor and the depth depends on the frequency and the resistance of the conductor (so-called skin effect).
[0009] Second, the plasma generated at the contact of the skin, due to the radio frequency and a high vacuum generated by a suitable pump, is composed of high energy gas ions that strike the surface of the skin, thereby generating heat in the superficial layer of the skin.
[0010] The interaction with the skin has some similarities to the interaction described in the patent application entitled “Method and Apparatus For Skin Brown Spot Removal”, patent application Ser. No. 09/361,407, which is incorporated in its entirety herein by reference.
[0011] One advantage of such an approach is by not having electrodes in contact with the skin, a more even distribution of the radio frequency current in the skin is achieved. Also, there is achieved a combined action from the striking gas ions and a more accurate control of the power applied to the skin surface, due to the higher impedance of the plasma that controls the current independently from the electrical conductivity value of the skin.
[0012] The present invention relates to an apparatus and a method for skin resurfacing treatment, which provides induced thermal damage of the skin by radio frequency heating and by ion bombardment of the skin.
[0013] This dual effect may be achieved by using a pulsed radio frequency generator connected to a probe for coupling to the skin. The probe is preferably made of a non-conductive material (such as glass or plastic), and enables the application of a high vacuum to the skin surface (e.g., 5-10 millibars) over a predetermined (e.g., round) portion of the skin, by using a non-conductive pipe connected to a vacuum pump. At a suitable distance (around 10 millimeters) from the surface of the skin, an electrode (that is housed within the probe) is used to generate a radio frequency field between the electrode itself and the surface of the skin. After reaching a sufficient vacuum (e.g., 5-10 millibars of atmospheric pressure), a high voltage radio frequency electric field is applied between the electrode and the surface of the skin, due to a radio frequency pulse applied to the electrode. Such a radio frequency field triggers a glow discharge inside the probe between the electrode and the skin. A radio frequency current, due to the low impedance of the glow discharge, flows evenly on the surface of the skin, and, due to the skin effect, is limited to the glow discharge area in a depth of about 300 microns. In the surrounding tissues, the current density decreases by the square of the distance from the area covered by the glow discharge within a depth of 300 microns. Moreover, the high energy ions of the glow discharge strike the surface of the skin, thereby providing a plasma skin resurfacing that can be used to remove spider veins, skin brown spots, or port wine stains, for example.
[0014] The present invention provides a controlled heating of a selected portion of the skin to a depth of about 300 microns. As a result, it is possible to reach a desired temperature of 70 degrees C or more, which triggers controlled damage to the skin cells to achieve a desired effect. The temperature reached in the described volume of the skin depends primarily on the selected pulse length and the power of the radio frequency generator. Preferably, a temperature reached in the described volume of the skin is a temperature in the range of from 75 degrees C to 95 degrees C.
[0015] To achieve a substantially uniform heating of a volume of the skin, a method according to the invention includes:
[0016] 1) Application of a probe to the skin, where the probe is held against an open area on the skin of about one square centimeter, where the probe includes an electrode at a distance of 10 millimeters (plus or minus a few millimeters) from the skin surface, and where a vacuum suction pipe is connected to the probe.
[0017] 2) Generation of a high vacuum inside the probe and at the surface of the skin by connection of the probe to a high vacuum pump, by way of the vacuum suction pipe.
[0018] 3) Application of high voltage at a frequency of 21 MHz in the probe between the electrode and the skin, by way of a pulsed radio frequency generator connected to the probe by way of a conductive cable.
[0019] 4) Generation of a glow discharge for a time less than 1 second sustained by a power less than 500 W.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings with like reference numerals indicating corresponding parts throughout, and wherein:
[0021] [0021]FIG. 1 shows a probe that may be utilized to treat a skin surface in order to provide relatively uniform skin heating, in accordance with a first embodiment of the invention;
[0022] [0022]FIG. 2 shows a system that may be utilized to treat a skin surface to provide relatively uniform skin heating, in accordance with the first embodiment of the invention; and
[0023] [0023]FIG. 3 shows a probe that may be utilized to treat a skin surface, in accordance with a second embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Preferred embodiments of the present invention will be described in detail hereinbelow, with reference to the drawings.
[0025] According to the present invention, a probe is put in contact with the skin to be treated (e.g., so as to remove spider veins or brown spots or port wine stains from the skin surface, for example).
[0026] In a first embodiment of the invention, as seen in FIG. 1, the probe 100 is V-shaped and is preferably made from polycarbonate. However, other types of plastic materials or glass or suitable insulating material may be used for the probe 100 . Referring now to FIGS. 1 and 2, a first upper end of the V-shaped probe 100 is connected to a vacuum suction pipe 210 , and a second upper end of the V-shaped probe 100 is connected to a coaxial cable 220 . The coupling of the vacuum suction pipe 210 to the first upper end of the probe 100 and the coupling of the coaxial cable 220 to the second upper end of the probe 100 are air-tight couplings. That way, a vacuum can be formed within the probe 100 . The bottom end of the V-shaped probe 100 has an opening that is to be placed in direct contact with a portion of the skin to be treated (shown as cross-hatched area 107 in FIG. 1), to provide an air-tight coupling of the opening against the skin surface.
[0027] The opening of the probe 100 preferably has a smooth round edge in order to assure a tight coupling with the skin and to avoid vacuum leakage. The opening is preferably round in shape, but any other shape can be used. In the first embodiment, the opening has a diameter of 8 millimeters, but other sizes may be utilized while remaining within the scope of the invention. For example, a larger diameter opening may be used by increasing the stroke of the vacuum pump 230 , the diameter of the suction pipe and the power of the radio frequency generator 240 . The power of the radio frequency generator 240 should be increased linearly with the increase of the surface covered by the glow discharge, in order to obtain substantially the same temperature on the skin.
[0028] The first upper end of the V-shaped probe 100 is connected to the coaxial cable 220 by way of a glass insulator 180 fed through to the probe 100 . The glass insulator 180 covers one end of the coaxial cable 220 that is coupled to the probe 100 . A copper wire 152 is incased within the glass insulator 180 , and is preferably welded to a terminal end of an inner wire of the coaxial cable 220 .
[0029] In case of feeding of gas, as in the second embodiment to be described later, the upper part of the probe is modified in order to enable a flow of gas between the copper wire and the glass insulator. Glass is used instead of plastic for the wire insulator within the probe, due to the high temperature that the electrode reaches during the operation of the probe for treating a patient's skin. Other materials, such as ceramic, could be used as well. A suitable glue 133 is used in order to assure that the vacuum is tight and that no leaks occur between the copper wire 152 and the glass insulator 180 (at the top portion of the probe 100 in the view of FIG. 1).
[0030] In the first embodiment, an electrode 170 is formed at a distal end of the copper wire 152 , where the copper wire is wound by several turns with a diameter of about 1 millimeter for each of the turns, thereby forming the electrode 170 . For example, five turns are used in the first embodiment, but other numbers of turns, as well as turn diameters, may be used while keeping within the scope of the invention. A glow discharge emanates from the electrode 170 when subject to pulsed radio frequency energy. The electrode 170 is disposed within the probe 100 in such as manner as to not be in contact with either the walls of the probe 100 or the surface of the skin. As explained above, the copper wire 152 is fitted inside the glass insulator 180 and is connected with an inner conductor (wire) of the coaxial cable 220 , so as to receive radio frequency energy from the radio frequency pulse generator 240 by way of the coaxial cable 220 .
[0031] The distance between the last turn of the electrode 170 (that is furthest from the coaxial cable 220 ) and the bottom opening of the V-shaped probe 100 is preferably 10 millimeters. That range may be varied (e.g., 5-20 mm range, for example) to provide a desired temperature to the skin. The positioning of the turns of the electrode 170 and the copper wire 152 is such that the turns are orthogonal to the surface of the opening, in order to have an even distribution of the electric field as it impinges on the surface of the skin.
[0032] The first upper end of the V-shaped probe 100 is connected through the suction (or vacuum) pipe 210 to the high vacuum pump 230 . In the first embodiment, an oil rotary pump is used which can provide up to a 5 millibar vacuum.
[0033] In the first embodiment, the coaxial cable 220 has a length of 2.3 meters, and is used as an impedance transformer from the low impedance output of the radio frequency generator 240 (52 ohm) to the probe 100 , to provide for a glow discharge at a desired (e.g., 21 MHz) frequency. Other cable length are suitable at different frequencies and with other types of radio frequency generators, as well as high voltage radio frequency transformers.
[0034] The radio frequency generator 240 used in the present invention may be a conventional power generator having a pulse duration that is selectable, and having an output power capability of up to 500 W. The triggering of a pulse may be done by a footswitch 290 , for example, or by other ways (e.g., toggle switch on the housing of the radio frequency generator 240 ). A preferred pulse duration is a value of between 1 milliseconds and 1000 milliseconds. An output power of the radio frequency generator 240 may be between 1 and 500 W, depending on the desired temperature to which the skin surface is to be heated. Also, the output radio frequency may be a value within the range of between 2 MHz and 52 MHz. Upon selecting a different frequency, the depth of the heated volume of the skin by the radio frequency current vary, i.e., the higher the frequency, the less the depth. The cable length of the coaxial cable 220 is chosen in order to match the high impedance of the glow discharge with the low impedance of the radio frequency pulse generator 240 , and is approximately one-fourth of the wavelength of the radio frequency traveling inside the coaxial cable 220 .
[0035] When the probe 100 is placed in contact with a desired area of a patient's skin to be treated, the vacuum pump 230 is activated. Upon reaching a vacuum pressure of 10 millibars or less, the footswitch 290 is then activated, thereby enabling the generation of the radio frequency voltage. The radio frequency voltage travels along the coaxial cable 220 to the electrode 170 , whereby a glow discharge is generated due to the vacuum within the probe 100 . The glow discharge within the probe 100 is shown as the gas-like region 141 in FIG. 1. As seen in FIG. 2, the patient is preferably grounded, to enhance the attraction of the gas ions within the glow discharge to the patient's skin.
[0036] Radio frequency current as well gas ions are applied to the surface of the skin under the opening of the probe 100 . Gas ions of the glow discharge act as a conductor, enabling the flow of current. When the gas ions strike the surface of the skin at high speed, they penetrate inside and they lose their charge, thus enabling the flow of current.
[0037] The frequency generator 240 is switched off after the preselected pulse width of radio frequency energy has been applied to the probe 100 . This enables the reaching of a desired superficial temperature of the skin, so as to generate a desired amount of heat damage of the skin cells under the probe 100 (so as to remove port wine stains or spider veins or skin brown spots, for example).
[0038] In a second embodiment of the invention, as shown in FIG. 3, a supply of low pressure gas, such as Helium, is provided to a third input port of the probe 100 ′ in order to maintain a gas of controlled composition at a desired vacuum pressure (e.g., 10-50 millibars) over the skin. This low pressure gas is provided by a gas source (e.g., external canister of gas) that feeds the gas through an additional (third) input port of the probe 100 ′. As in the first embodiment, the first input port of the V-shaped probe 100 ′ is connected to the radio frequency pulse generator 240 by way of a coaxial cable 220 , and the second input port of the V-shaped probe 100 ′ is connected to the vacuum source 230 by way of the vacuum pipe 210 , to thereby provide a vacuum or near-vacuum condition within the probe 100 ′. In the second embodiment, the glass insulator 180 ′ has an opening to expose a portion of the copper wire 152 to the flow of helium gas supplied from the third input port of the probe 100 ′. This enables a flow of gas between the copper wire 152 and the glass insulator 180 ′, to provide a more stable glow discharge within the probe 100 ′.
[0039] In this second embodiment, the low pressure gas is supplied at a pressure of between 10-50 millibars, in order to stabilize the glow discharge and to selectively inject ions in the skin. Other gases besides Helium may be utilized while remaining within the scope of the invention, for example, Nitrogen or Oxygen or mixtures of gas including Helium may be used instead of Helium only.
[0040] While the present invention has been described with respect to the preferred embodiments, other types of configurations may be possible, while remaining within the spirit and scope of the present invention, as exemplified by the claims. | A radio frequency generated plasma is provided to a skin surface in a controlled manner, in order to heat and selectively damage a thin superficial layer, thereby inducing a renewal process of the epidermis. The plasma is generated by providing a vacuum to the probe, and also providing an rf pulse to an electrode within the probe, thereby creating a glow discharge that includes gas ions that contact the skin and cause the skin to heat up. | 0 |
FIELD OF THE INVENTION
The invention relates to semiconductor amplifier circuits and, more particularly, to a differential amplifier circuit with an unlocking device.
BACKGROUND OF THE INVENTION
Differential amplifiers are widely used in the telecommunications field. They allow for processing of weak signals conveying voice signals, and, more generally, data. A differential structure is particularly preferred in data transfer networks of wired networks (Wide Area Network) found in Asynchronous Transfer Mode-type (ATM) networks or Asynchronous Digital Subscriber Line-type (ADSL) networks as well as their principal derivatives HDSL (commonly designated by the generic term XDSL).
Generally, a differential structure has the effective advantage of eliminating harmonics and second-order non-linearities in distortion noise. Furthermore, a differential structure ensures greater immunity to common mode interference, such as the interference that power supply circuits of electronic circuits experience. Differential amplifier circuits, particularly those using complementary-type MOS type transistors, which are used in bi-CMOS technology, frequently use power supply sources. Such power supply sources often experience difficult start-up transients and blocking phenomena preventing the amplifier from operating.
Circuits for overcoming this problem and avoiding power supply source blocking in a semiconductor circuit are known. French patent application No. 2,767,976 entitled “Dispositif d'aide au démarrage pour une pluralité de sources de courant” discloses such a start-assisting device. The start-assisting device which, though not specifically adapted to an amplifier structure, is useful to supply devices for microprocessors and electronic apparatus. This device comprises a start-assisting device, which provides power supply sources with a start current for a transient period, until a steady state can be established. A complementary inhibiting device is thereafter required for steady-state operation.
Although differential amplifiers are especially important in integrated circuits used in telecommunications, it is still desirable to design start-assisting devices that are particularly adapted to their structure and can be easily and cost-effectively manufactured without requiring the addition of new circuits. However, a differential amplifier structure that directly and easily incorporates a suitable unlocking circuit is not yet available.
SUMMARY OF THE INVENTION
The invention is aimed at providing a differential amplifier structure having an efficient, simple unlocking device, which only requires the addition of a very limited number of other components.
Another object of the invention is to provide an unlocking device which is adapted to the architecture of a differential amplifier to be integrated into an integrated circuit, and, in particular, that uses CMOS-type components of bi-CMOS technology.
Another object of the invention provides a differential amplifier structure, which is adapted to telecommunication network requirements and, particularly, ADSL or HDSL-type links.
The invention achieves these objects through a differential amplifier structure having a first stage including first and second transistors of identical polarity, such as NMOS-type transistors, which are assembled to provide a differential amplifier. The first and second transistors are fed by first and second mirror current sources respectively, which are controlled by a control circuit supporting common mode. The common mode control circuit has two inputs receiving a reference voltage V CM and a voltage representative of the common mode voltage of the amplifier.
A second Miller stage comprises third and fourth transistors of an opposite-type from the former transistor, for example PMOS. The inputs of the third and fourth transistors receive output signals from the first stage, which are used to increase the open loop gain of the amplifier circuit and to set the gain-bandwidth product of the amplifier. An additional unlocking circuit is inserted between the common mode voltage and the Miller stage inputs. The additional unlocking circuit causes controlled conduction of the third and fourth PMOS-type transistors until the common mode voltage reaches a value which is significantly close to the reference value.
Thus, it is ensured that the Miller stage is set for conducting and, hence, the first and second current sources are set for conducting, which ensures the amplifier operation. Once the common mode voltage rises back up to a normal operational value, the unlocking circuit locks and re-establishes impedance between the Miller stage output and the common mode voltage, thereby enabling the amplifier to operate in a linear mode.
Preferably, the unlocking circuit is provided by two MOS-type transistors causing short-circuiting between the common mode voltage and the Miller stage inputs. The drain terminal of each NMOS transistor (which can also be NPN transistors) or unlocking transistor is connected to a corresponding gate of one of the third and fourth transistors. Furthermore, both unlocking transistors have a source connected to the terminal representative of the common mode voltage. The gates of the unlocking transistors are connected to a reference voltage V CM and cause the Miller stage transistors to conduct when the true value of the common mode is significantly smaller than the reference value V CM .
In a particular embodiment, the amplifier may comprise a cascade stage comprising, for instance, bipolar transistors. More particularly, the differential amplifier may comprise a first stage comprising a first and a second NMOS-type transistor (which can also be NPN-type transistors) assembled as a differential pair. The gates of the first and second NMOS-type transistors may receive input signals via feedback resistors from a common source connected to a third current source.
The differential amplifier may further comprise a second Miller gain stage comprising third and fourth PMOS-type transistors, for example. The third and a fourth PMOS-type transistors may be assembled as a common source, each associated with a current source and a capacitor. The second Miller gain stage output may be connected to output terminals and having one input.
The differential amplifier may further comprise fifth and sixth PMOS-type transistors, for instance. The fifth and sixth PMOS-type transistors provide the first and second current sources, respectively, feeding the first and the second NMOS-type transistors, which form the differential pair of transistors. The fifth and sixth transistors may be assembled as a common source and each having a drain. The drains of the fifth and sixth transistors are connected to corresponding drains of the first and second transistors in the differential pair, as well as a gate controlled by the common mode supporting circuit.
The differential amplifier may further comprise an unlocking circuit comprising seventh and eighth NMOS-type transistors, for example, having gates that receive a reference value V CM . The unlocking circuit may short-circuit the common mode voltage and the gates of the third and fourth transistors, which form the Miller stage when the common mode voltage goes below the reference value V CM .
The invention is especially adapted to designing wide-band amplifiers used in wired telecommunications networks, and, more particularly, to wired telecommunication networks found in the Asynchronous Digital Line Subscriber-type networks and their derivatives.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary differential amplifier circuit comprising a Miller gain stage, which may be advantageously provided with an unlocking circuit, according to the present invention;
FIG. 2 illustrates a differential amplifier structure shown in FIG. 1 including the unlocking circuit, according to the present invention;
FIG. 3 illustrates a second embodiment of the differential amplifier shown in FIG. 2 including an additional cascade circuit, according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates an example of a differential amplifier comprising a Miller gain stage and which can be advantageously provided with the unlocking circuit described below. The differential amplifier comprises a pair of NMOS-type transistors 10 and 20 . Although the preferred embodiment will describe the use of NMOS-type transistors to form the differential pair, it is clear that those skilled in the art will readily adapt the structure to an architecture in which the differential pair will be based on PMOS-type transistors. The amplifier is fed by a power supply source supplying a voltage V dd .
The source electrodes of NMOS transistors 10 and 20 are connected to a current source 1 (I 3 ) which, in turn, is connected to ground or other reference voltage. Each transistor of the differential pair 10 and 20 is fed through its drain by a current source based respectively on a PMOS transistor 11 and a mirroring PMOS transistor 21 . The source and drain terminals of transistor 11 are connected to supply terminal V dd and to the drain terminal of transistor 10 , respectively. The source and drain terminals of transistor 11 are connected to supply terminal V dd and to the drain terminal of transistor 20 respectively.
Transistors 11 and 21 are mounted in a current mirror configuration cooperating with a common mode supporting stage, which comprises a second differential pair associated with a current source 2 (I 4 ) and a PMOS-type transistor 5 . More particularly, the second differential pair comprises two transistors 3 and 4 , sources of which are connected to a current source 2 (I 4 ) which, in turn, is connected to ground. The drain electrodes of transistors 3 and 4 are connected to the drain of transistor 5 and supply terminal V dd , respectively.
The gate of transistor 3 is connected to the midpoint of a resistive bridge, comprising two resistors 17 and 27 generally of equal values, the ends of which are connected to output terminals O 1 and O 2 of the differential amplifier. The bridge resistors 17 and 27 are used to obtain, at the midpoint, a potential representative of the common mode value of the differential amplifier outputs O 1 and O 2 . The gate of transistor 4 receives a reference voltage, V CM , which is used to set the common mode stage bias level and which is generally set to V dd /2 to obtain a maximum dispersion output signal at terminals O 1 and O 2 .
The gates of transistors 5 , 11 and 21 are all connected together. The gate and drain of transistor 5 are connected to each other, thus ensuring it operates within the square zone of its characteristic I (V GS ). Thus, the transistors are mounted in current mirror configuration and a same drain current flows through them because, as they are substantially identical, they undergo the same variations of gate-source voltage V GS .
The differential pair formed by transistors 10 and 20 is used as a first stage for a second Miller gain stage, which is comprised of a pair of PMOS-type transistors 12 and 22 assembled as a common source. More precisely, transistor 10 has its drain connected to the gate of transistor 12 , the source of which is connected to supply terminal V dd . Similarly, transistor 20 has its drain connected to the gate of transistor 22 , the source of which is connected to supply terminal V dd . Transistor 12 has its drain connected to a current source 14 connected in turn, at the other end, to ground. Similarly, transistor 22 has its drain connected to a current source 24 connected in turn, at the other end, to ground. The transistor 12 has its drain also connected to the output terminal O 2 of the differential amplifier. Similarly, the transistor 22 has its drain also connected to the output terminal O 1 of the differential amplifier.
A pair of capacitors 13 and 23 complete the Miller structure. The capacitor 13 is connected between the drain and source of transistor 12 . Similarly, the capacitor 23 is connected between the drain and source of transistor 22 . The capacitors are calibrated to set the gain-bandwidth product of the corresponding Miller stage. It is to be noted that the latter is designed to operate in class A, current sources 14 and 24 will therefore be calibrated accordingly to discharge the current in the amplifier load.
Associating the differential pair of transistors 10 and 20 and the Miller gain stage transistors 12 and 22 ensures a particularly high open loop gain for all of the amplifier and further helps to set its gain-bandwidth product. Feedback resistors 15 (R 1 ), 16 (R 2 ), 25 (R 3 ) and 26 (R 4 ) set the open loop gain to the desired value which is R 1 /R 2 =R 3 /R 4 . More precisely, as is shown in FIG. 1, resistors 15 and 16 together form a resistor bridge, the ends of which are connected to output terminal O 1 and input terminal E 1 of the differential amplifier, respectively. The midpoint of the resistor bridge is connected to the gate of transistor 10 . Similarly, resistors 25 and 26 define a bridge, the ends of which are connected to output terminal O 2 and input terminal E 2 respectively, and the midpoint of which is connected to the gate of transistor 20 .
As shown in FIG. 1, the common mode supporting circuit allows setting common mode voltages about the reference value, that is to say V CM =V dd /2. Indeed, it can be seen that should the potential of one of the outputs increase for any reason, for instance a circuit temperature rise, the increase would affect the midpoint of the resistive bridge 17 and 27 , causing a corresponding voltage increase in the gate of transistor 3 . A flow of current would then flow through transistor 3 because the additional gate voltage of transistor 4 would still be set to the unchanged value of reference V CM . Currents in transistors 11 and 21 would then be modified to cause the output voltage to go back to the reference value.
It is noted that, at start-up, such a circuit can stay locked because of blockage of the current sources embodied by transistors 11 and 21 . As a matter of fact, at start-up, voltages at terminals E 1 , E 2 , O 1 and O 2 are all set to ground, which corresponds to a constant load. In such a case, current I 4 delivered by source 2 is entirely derived only by transistor 4 and no current flows through transistor 3 . All other transistors 5 , 11 , 21 are then blocked and the amplifier cannot operate. Similarly, source 1 stays blocked.
Even when the voltages at terminals E 1 and E 2 reach a suitable value, for example V dd /2, because of the amplifier preceding stage receiving a steady load, for instance, transistor pair 10 and 20 may become blocked. This can be the case with some configurations of feedback resistor values R 1 , R 2 and R 3 , R 4 , in particular, when the amplifier is used as a voltage attenuator. Therefore, having a common mode potential on both input terminals E 1 and E 2 may not be enough to ensure conduction of transistors 3 , 5 , 11 and 21 and allow the amplifier to operate in a linear mode.
To avoid a current source I 1 blockage, which would impede the overall operation of the amplifier, a very simple and efficient unblocking device is incorporated which will now be described with reference to FIG. 2 . For the sake of clarity, elements with common numerals from FIG. 1, will keep the same numerals in FIG. 2 . The amplifier again comprises a differential pair of transistors 10 and 20 , common mode supporting stage 3 and 4 , and a Miller gain stage including transistors 12 and 22 .
To ensure conduction of transistors 12 and 22 , the circuit has an additional pair of NMOS-type transistors connected between the midpoint of the resistive bridges 17 and 27 to follow the level of output potentials O 1 and O 2 in common mode and, the transistor gates of the Miller gain stage. As a consequence, at start-up, the transistor gates enable conduction of the Miller stage. For that purpose, as shown in FIG. 2, a first NMOS-type transistor 18 is provided, the drain of which is connected to the gate of transistor 12 , the source of which is connected to the midpoint of bridge resistors 17 and 27 tapping the common mode voltage.
A second NMOS-type transistor 28 having a drain connected to the gate of transistor 22 and a source connected to the midpoint of bridge resistors 17 and 27 , measuring the common mode value, is also provided. The gates of both transistors 18 and 28 are common and receive the reference voltage V CM . So when potentials of output terminals O 1 and O 2 are abnormally low, which is the case during start-up, NMOS-type transistors 18 and 28 are conductive and thus set corresponding Miller stage transistors 12 and 22 respectively to conduction. Therefore, a rise of the common mode potential is ensured. Consequently, a start-up current for transistor 5 and current mirrors formed by transistors 11 and 21 and finally in the differential pair of transistors 10 and 20 , is also achieved.
The disclosed unlocking circuit is found to be particularly efficient and, as is shown in FIG. 2, only needs two additional components. As a consequence, it can readily be incorporated in a semiconductor circuit. Further, it is noted that unlocking transistors 18 and 28 can be very small-sized transistors as a resistance amount of a few ohms is enough to ensure the Miller stage unlocking. Every differential amplifier can thus be provided easily and at a low cost with such a device, which automatically and simply self-inhibits as soon as a steady-state linear load is established. This represents an advantage over known unlocking systems.
Indeed it is noted that once the common mode potential reaches the reference value V CM , both transistors 18 and 28 are blocked thus allowing the amplifier to operate in linear mode. Here, no additional inhibiting circuit such as those in known systems is necessary. This unlocking device is especially adapted to the realisation of differential amplifiers and to incorporation thereof in integrated circuits.
FIG. 3 shows another embodiment for a differential amplifier structure further comprising a cascade circuit forming an impedance adapter between a differential pair of transistors 10 and 20 and a Miller gain stage. In this embodiment, the transistor 10 drain electrode is not connected directly to the transistor 11 drain electrode. Rather, an NPN-type bipolar transistor 19 is interposed between transistors 10 and 11 . More precisely, the transmitter and collector terminals of the NPN-type bipolar transistor 19 are connected to the transistor 10 drain terminal and the transistor 11 drain terminal, respectively.
Similarly, a bipolar transistor 29 , also of NPN-type, is interposed between transistor 20 and transistor 21 . More precisely, the transmitter and collector terminals of transistor 29 are connected to the transistor 20 drain terminal and the transistor 21 drain terminal, respectively. The bases of both transistors are connected to a resistor 7 dropping back to supply voltage V dd and to a current source 8 , the opposite end of which is connected to a ground.
As will be apparent to people qualified in the art, the advantage of the cascade circuit is to provide large impedance at the first stage comprised of the pair of transistors 10 and 20 to further increase the amplifier's open loop gain. As can be seen, this disclosed amplifier circuit is perfectly adapted to bi-CMOS technology. Furthermore, note that any person qualified in the art could very easily adapt the structure in FIG. 3 to a cascade circuit comprised of NMOS-type transistors instead of bipolar transistors. | A differential amplifier may include a first stage including a first transistor and a second transistor having the same polarity and assembled to constitute a differential amplifier. The first stage may be supplied by first and second mirror current sources. The differential amplifier may further include a common mode control circuit, which may include two inputs receiving a reference voltage VCM and a common mode voltage controlling the first and second mirror current sources, respectively. The differential amplifier may further include a Miller gain stage having inputs and for a setting gain-band product. The differential amplifier may further include an unlocking circuit, inserted between the common mode voltage and the Miller gain stage inputs, to cause the Miller gain stage to conduct on circuit start-up. | 7 |
FIELD OF THE INVENTION
This invention is directed to a method for minimizing damage to downhole equipment which is utilized during controlled pulse or high energy fracturing ("CPF"). More specifically, it is directed to the use of a shear thickening tamp which thickens and minimizes movement of said equipment.
BACKGROUND OF THE INVENTION
Stimulation of wells through mechanical fracturing can be accomplished by a method known as controlled pulse fracturing or high energy gas fracturing. A good description of this method appears in an article by Cuderman, J. F., entitled "High Energy Gas Fracturing Development," Sandia National Laboratories, SAND 83-2137, October 1983. Using this method enables the multiple fracturing of a formation or reservoir in a radial manner which increases the possibility of contacting a natural fracture. In the practice of this method, a housing means for containing a propellant is suspended into a wellbore. This housing means is placed downhole next to the oil or hydrocarbonaceous fluid productive interval.
The propellant in the housing means or molded body can belong to the modified nitrocellulose or the modified and unmodified nitroamine propellant class. Suitable solid propellants capable of being utilized include a double-based propellant known as M-5. It contains nitroglycerine and nitrocellulose. Another suitable propellant is a composite propellant which contains ammonium perchlorate in a rubberized binder. The composite propellant is known as HXP-100 and is purchasable from the Holex Corporation of Hollister, Calif. M-5 and HXP-100 propellants are disclosed in U.S. Pat. No. 4,039,030 issued to Godfrey et al. which is hereby incorporated by reference.
After placing the propellant means for creating multiple fractures into a housing means and suspending it downhole near all the oil or hydrocarbonaceous fluid productive interval, it is ignited. Ignition of the propellant means for creating the multiple fractures causes the generation of heat and gas pressure. To contain the generated propellant energy within the wellbore and formation, an aggregate stem, generally composed of cement, is placed above the housing means containing the propellant thereby sealing the wellbore. The suspended housing means and ignition means passes through the aggregate stem.
After ignition of the propellant means it is difficult to remove the aggregate stem, which often has to be drilled out. When removing the aggregate stem, the suspension means, generally a cable, and the ignition means, along with remnants of the housing means which previously contained the propellant, frequently fall into the wellbore. This debris may interfere with production of hydrocarbonaceous fluids from the formation. Drilling out the aggregate often damages the wellbore and formation.
Therefore, what is needed is a method to reduce the pressure forces on downhole equipment used during a CPF operation so as to avoid damaging said equipment and formation.
SUMMARY OF THE INVENTION
This invention is directed to a method for limiting upward movement of a housing means containing a propellant which is suspended from a wireline along with an igniting means during a controlled pulse fracturing operation. In the practice of this invention, a housing means containing a propellant is suspended into a shear thickening fluid within a wellbore near a formation's productive interval. The height of the fluid is sufficient to contain energy released from said propellant. The fluid contains an additive in an amount sufficient to cause it to shear thicken when moved upwardly by the pressure of the expanding gases resultant from ignition of the propellant.
After suspending the housing means into the fluid, the propellant is ignited thereby causing the generation of energy and pressure sufficient to initiate more than two radial fractures which are extended. The sudden movement of the fluid following propellant ignition causes the fluid to thicken thereby restricting movement of the wireline upwardly, thereby minimizing tool movement and lessening tool damage. After ignition, and when conditions in the wellbore and formation have reached the desired level of stability, said fluid can be removed.
It is therefore an object of this invention to minimize equipment damage following a CPF treatment through use of a shear thickening fluid tamp which reduces movement of the CPF tool and wireline.
It is another object of this invention to use a shear thickening fluid to slow or stop upward movement of a propellant housing means so as to minimize downhole equipment damage.
It is yet another object of this invention to use a shear thickening fluid to cause a high resistance to upwardly flowing gases eminating from an ignited propellant.
It is a still further object of this invention to provide for a shear thickening fluid which will be easy to place and remove from a well production string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphic representation of a tamp fluid and housing means containing the propellant before ignition.
FIG. 2 is a graphic representation of a tamp fluid and housing means containing the propellant after ignition.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the practice of this invention, referring to FIG. 1, a housing means 16 or molded tool body containing a propellant is placed into a wellbore 12 which penetrates a hydrocarbonaceous fluid producing formation 10 near the formation's productive interval. Wellbore 12 contains perforations 28 which communicate with the formation's productive interval. Housing means 16 is suspended into wellbore 12 in close proximity to the productive interval via a retrieval means, which generally will be a cable 18. A fluid 22 is directed into wellbore 12 thereby immersing housing means 16 for some vertical distance above housing means 16. Fluid 22 in wellbore 12 is of a height sufficient to balance the pressure in formation 10. Generally, this height will be at least about 500 feet above the housing means 16. Wellbore 12 is thereby filled with fluid 22 above the housing means. When filled in this manner, fluid 22 serves as a tamp for the propellant contained in housing means or canister 16. In order to ignite the propellant contained in the housing means or canister 16, a means for igniting the propellant is connected to housing means 16. The other end of the means for ignition is connected or affixed to a location at or above ground level above wellbore 12. Said means for ignition will generally be a conduit 20 containing an electrical wire which wire can be used to generate an electrical spark within canister 16 containing the propellant. Both retrieval means, 18 and ignition means 20 proceed to the surface and through the cap (not shown) on wellbore 12.
Upon ignition of the propellant, heat and gas are released within wellbore 12. The sudden movement of fluid 22 following the ignition of the propellant tends to drive cable 18 and the remnant of housing means or canister 16 upwards by gas expansion. However, the characteristics of the fluid are such that the movement caused by the rapidly expanding gas makes the fluid thicken. While not desiring to be bound by any particular theory, it is believed that shear thickening occurs because the frictional forces between suspended compound particles increase greatly as the velocity of the suspending medium increases, thus causing a high resistance to flow. Thus, the fluid becomes substantially more viscous and more resistant to flow up the production string or tubing when fluid velocities increase under the force generated by the ignited propellant. The shear thickening fluid slows or stops the upward movement of the wireline and housing means which minimizes damage to the wireline and housing means. Since substantially less movement is experienced by cable 18 and canister 16, damage to this equipment is lessened.
Fluids that can be utilized for shear thickening purposes include an aqueous mixture of compounds selected from a member of the group consisting of titanium oxide, cornstarch, polyvinyl alcohol-sodium borate mixtures, aqueous solutions of polymethacrylates and poly (alkyl methacrylates), gum arabic and borate ions, and guar gum and borate ions. Some of these shear thickening fluids are discussed in U.S. Pat. Nos. 3,378,073 and 3,400,796 which issued to Savins and Savins et al. respectively. These patents are hereby incorporated by reference herein in their entireties. The concentration of the thickening compounds utilized should be sufficient to impart the desired shear thickening qualitites and effect.
Concentrations of polyvinyl alcohol and borate ions which can be used herein are discussed in U.S. Pat. No. 3,378,073. Concentrations of polymethacrylates and poly (alkyl methacrylates) are discussed in U.S. Pat. No. 3,400,796. Other useful shear thickening materials, and concentrations therefor may be found in the literature which materials also include the category of dilant materials. U.S. Pat. No. 4,751,966 mentions the use of a prempable gel for use in increasing the vertical drag. This patent is hereby incorporated by reference herein. The concentration of compound utilized should be adjusted so as to obtain the maximum shear thickening effect for flow conditions anticipated in a specific CPF application.
As will be understood by those skilled in the art, the concentration of compound will depend upon the composition of the compound utilized. Any concentration of compound used should impart a shear thickening effect along the fluid/solid interfaces in a well flow system where CPF downhole equipment is utilized.
Once ignited, as is shown in FIG. 2, the heat, gas and pressure created by the propellant causes a total or partial disintegration of housing means or canister 26 which contained the propellant. However, as is shown in FIG. 2, cable 18 and ignition line 20 remain intact having sustained minimum damage. Once the pressure on wellbore 12 has dissipated, retrieval cable 18, and ignition line 20, along with remnants of housing means or canister 26 are removed from the wellbore.
Fluid 22, after ignition, flows into wellbore 12 where it can be removed by any suitable physical means such as pumping to the surface. After any debris and viscous fluid have been removed from the wellbore, hydrocarbonaceous fluids can be produced from a formation when the created fractures intersect a natural hydrocarbonaceous fluid containing fracture.
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of this invention as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims. | A method for minimizing damage to downhole equipment utilized during controlled pulse fracturing ("CPF") where a shear thickening fluid is used as a tamp. A shear thickening aqueous fluid having particles therein overlies a CPF device thereby creating a tamp. Movement of the fluid by pressure forces resultant from the ignited propellant causes the fluid to thicken. This thickened fluid prevents and device and wireline from moving upwardly which minimizes damage thereto. | 4 |
This is a continuation-in-part of U.S. Ser. No. 08/062,515 filed May 14, 1993, now abandoned.
BACKGROUND OF INVENTION
This invention relates to chemical compounds having pharmacological activity, to pharmaceutical compositions which include these compounds, and to a pharmaceutical method of treatment. More particularly, this invention concerns certain N-acyl sulfamic acid esters (or thioesters), N-acyl sulfonamides, and N-sulfonyl carbamic acid esters (or thioesters) which inhibit the enzyme, acyl-coenzyme A:cholesterol acyltransferase (ACAT), pharmaceutical compositions containing these compounds, and a method of treating hypercholesterolemia and atherosclerosis.
The compounds of the instant invention show increased chemical stability over those of U.S. Pat. No. 5,245,068.
In recent years the role which elevated blood plasma levels of cholesterol plays in pathological conditions in man has received much attention. Deposits of cholesterol in the vascular system have been indicated as causative of a variety of pathological conditions including coronary heart disease.
Initially, studies of this problem were directed toward finding therapeutic agents which would be effective in lowering total serum cholesterol levels. It is now known that cholesterol is transported in the blood in the form of complex particles consisting of a core of cholesteryl esters plus triglycerides and a variety of types of protein which are recognized by specific receptors. For example, cholesterol is carried to the sites of deposit in blood vessels in the form of low density lipoprotein cholesterol (LDL cholesterol) and away from such sites of deposit by high density lipoprotein cholesterol (HDL cholesterol).
Following these discoveries, the search for therapeutic agents which control serum cholesterol turned to finding compounds which are more selective in their action; that is, agents which are effective in elevating the blood serum levels of HDL cholesterol and/or lowering the levels of LDL cholesterol. While such agents are effective in moderating the levels of serum cholesterol, they have little or no effect on controlling the initial absorption of dietary cholesterol in the body through the intestinal wall.
In intestinal mucosal cells, dietary cholesterol is absorbed as free cholesterol which must be esterified by the action of the enzyme, acyl-CoA:cholesterol acyltransferase (ACAT) before it can be packaged into the chylomicrons which are then released into the blood stream. Thus, therapeutic agents which effectively inhibit the action of ACAT prevent the intestinal absorption of dietary cholesterol into the blood stream or the reabsorption of cholesterol which has been previously released into the intestine through the body's own regulatory action.
SUMMARY OF THE INVENTION
The present invention is directed to compounds of Formula I below, methods for using the compounds of Formula I, pharmaceutical compositions thereof, and processes for preparing the compounds.
The first aspect of the invention is a compound of Formula I ##STR2## or a pharmaceutically acceptable salt thereof wherein: X and Y are selected from oxygen, sulfur and (CR'R") n , wherein n is an integer of from 1 to 4 and R' and R" are each independently hydrogen, alkyl, alkoxy, halogen, hydroxy, acyloxy, cycloalkyl, phenyl optionally substituted or R' and R" together form a spirocycloalkyl or a carbonyl; with the proviso at least one of X and Y is --(CR'R") n -- and with the further proviso when X and Y are both (CR'R") n and R' and R" are hydrogen and n is one, R 1 and R 2 are aryl;
R is hydrogen, a straight or branched alkyl of from 1 to 8 carbon atoms or benzyl;
R 1 and R 2 are each independently selected from
(a) phenyl or phenoxy each of which is unsubstituted or is substituted with 1 to 5 substituents selected from
phenyl,
an alkyl group having from 1 to 6 carbon atoms and which is straight or branched,
an alkoxy group having from 1 to 6 carbon atoms and which is straight or branched;
phenoxy,
hydroxy,
fluorine,
chlorine,
bromine,
nitro,
trifluoromethyl,
--COOH,
--COOalkyl wherein alkyl has from 1 to 4 carbon atoms and is straight or branched,
--(C 2 ) p NR 3 R 4 wherein p is zero or one, and each of R 3 and R 4 is selected from hydrogen or a straight or branched alkyl group having 1 to 4 carbon atoms;
(b) 1- or 2-naphthyl unsubstituted or substituted with from 1 to 3 substituents selected from
phenyl,
an alkyl group having from 1 to 6 carbon atoms and which is straight or branched,
an alkoxy group having from 1 to 6 carbon atoms and which is straight or branched;
hydroxy,
phenoxy,
fluorine,
chlorine,
bromine,
nitro,
trifluoromethyl,
--COOH,
--COOalkyl wherein alkyl has from 1 to 4 carbon atoms and is straight or branched,
--(CH 2 ) p NR 3 R 4 wherein p, R 3 and R 4 have the meanings defined above;
(c) arylalkyl;
(d) a straight or branched alkyl chain having from 1 to 20 carbon atoms and which is saturated or contains from 1 to 3 double bonds; or
(e) adamantyl or a cycloalkyl group wherein the cycloalkyl moiety has from 3 to 6 carbon atoms; with the provisos:
(i) where X is (CH 2 ) n , Y is oxygen, and R 1 is a substituted phenyl, then R 2 is a substituted phenyl;
(ii) where Y is oxygen X is (CH 2 ) n , R 2 is phenyl or naphthyl, then R 1 is not a straight or branched alkyl chain; and
(iii) the following compounds are excluded:
______________________________________X Y R R.sub.1 R.sub.2______________________________________CH.sub.2 O H (CH.sub.2).sub.2 CH.sub.3 PhCH.sub.2 O H CH.sub.3 PhCH.sub.2 O H ##STR3## i-Pr.______________________________________
Preferred compounds of the instant invention are those of Formula I:
wherein R 1 is phenyl or is phenyl disubstituted in the 2,6-positions,
wherein R 2 is phenyl or is phenyl disubstituted in the 2,6-positions,
wherein each of R 1 and R 2 is phenyl,
wherein each phenyl is disubstituted in the 2,6-position,
wherein R 1 is phenyl disubstituted in the 2,6-positions and R 2 is phenyl trisubstituted in the 2,4,6-positions,
wherein R 1 is 2,6-bis(1-methylethyl)phenyl and R 2 is 2,6-bis(1-methylethyl)phenyl or 2,4,6-tris(1-methylethyl)phenyl,
wherein one of R 1 and R 2 is the group ##STR4## wherein t is zero or 1 to 4; w is zero or 1 to 4 with the proviso that the sum of t and w is not greater than 5; R 5 and R 6 are each independently selected from hydrogen or alkyl having from 1 to 6 carbon atoms, or when R 5 is hydrogen, R 6 can be selected from the groups defined for R 7 ; and R 7 is phenyl or phenyl substituted with from 1 to 3 substituents selected from a straight or branched alkyl group having from 1 to 6 carbon atoms, straight or branched alkoxy group having from 1 to 6 carbon atoms, phenoxy, hydroxy, fluorine, chlorine, bromine, nitro, trifluoromethyl, --COOH, COOalkyl wherein alkyl has from 1 to 4 carbon atoms, or --(CH 2 ) p NR 3 R 4 wherein P, R 3 and R 4 have the meanings defined above.
Also preferred compounds of the instant invention are those of Formula I wherein
X is oxygen, sulfur or (CR'R") n ;
Y is oxygen, sulfur or (CR'R") n , with the proviso that at least one of X or Y is (CR'R") n wherein n is an integer of from 1 to 4 and R' and R" are each independently hydrogen, straight or branched alkyl of from 1 to 6 carbons, optionally substituted phenyl, halogen, hydroxy, alkoxy, acyloxy, cycloalkyl, or R' and R" taken together form a carbonyl or a spirocycloalkyl group of from 3 to 10 carbons;
R is hydrogen;
R 1 is phenyl optionally substituted, straight or branched alkyl of from 1 to 10 carbon atoms, cycloalkyl of from 3 to 10 carbon atoms;
R 2 is phenyl optionally substituted, straight or branched alkyl of from 1 to 10 carbon atoms, cycloalkyl of from 3 to 8 carbon atoms, phenoxy optionally substituted with the proviso that only if X is (CR'R") n can R 1 be optionally substituted phenoxy and only if Y is (CR'R") n can R 2 be optionally substituted phenoxy, and with the further proviso that at least one of R 1 and R 2 is optionally substituted phenyl or phenoxy.
More preferred compounds of the instant invention are those of Formula I wherein
X is oxygen;
Y is (CR'R") n wherein n is an integer of from 1 to 2;
R is hydrogen;
R 1 is optionally substituted phenyl;
R 2 is optionally substituted phenyl or phenoxy, straight or branched alkyl of from 1 to 10 carbons, or cycloalkyl of from 3 to 10 carbons; and
R' and R" are each independently hydrogen, straight or branched alkyl of from 1 to 6 carbons, optionally substituted phenyl, halogen, hydroxy, alkoxy, acyloxy, cycloalkyl, or R' and R" taken together form a carbonyl or a spirocycloalkyl.
The present invention also provides a pharmaceutical composition for regulating plasma cholesterol concentrations comprising a therapeutically effective amount of one or more compounds of Formula I. It further provides a method of treating hypercholesterolemia and for treating atherosclerosis comprising administering to a patient an effective amount of one or more compounds of Formula I with a pharmaceutically acceptable carrier.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the present invention provide a novel class of N-acyl sulfamic acid esters (or thioesters), N-acyl sulfonamides, and N-sulfonyl carbamic acid esters (or thioesters) which are ACAT inhibitors, rendering them useful in treating hypercholesterolemia and atherosclerosis.
In Formula I above, illustrative examples of straight or branched saturated hydrocarbon chains having from 1 to 20 carbon atoms include methyl, ethyl, n-propropyl, isopropyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-undecyl, n-dodecyl, n-hexadecyl, 2,2-dimethyldodecyl, 2-tetradecyl, and n-octadecyl groups.
Illustrative examples of straight or branched hydrocarbon chains having from 1 to 20 carbon atoms and having from 1 to 3 double bonds include ethenyl, 2-propenyl, 2-butenyl, 3-pentenyl, 2-octenyl, 5-nonenyl, 4-undecenyl, 5-heptadecenyl, 3-octadecenyl, 9-octadecenyl, 2,2-dimethyl-11-eicosenyl, 9,12-octadecadienyl, and hexadecenyl.
Straight or branched alkoxy groups having from 1 to 6 carbon atoms include, for example, methoxy, ethoxy, n-propoxy, t-butoxy, and pentyloxy.
Illustrative examples of straight or branched alkyl groups having from 1 to 6 carbon atoms as used in Formula I include methyl, ethyl, n-propyl, isopropyl, n-pentyl, n-butyl, and tert-butyl.
Illustrative examples of cycloalkyl groups, as used in Formula I, include cyclopentyl, cyclohexyl, cyclooctyl, tetrahydronaphthyl, and 1- or 2-adamantyl.
Spirocycloalkyl groups are, for example, spirocyclopropyl, spirocyclobutyl, spirocyclopentyl, and spirocyclohexyl.
Illustrative examples of arylalkyl groups are: benzyl, phenethyl, 3-phenylpropyl, 2-phenylpropyl, 4-phenylbutyl, 2-phenylbutyl, 3-phenylbutyl, benzhydryl, 2,2-diphenylethyl, and 3,3-diphenylpropyl.
Pharmaceutically acceptable salts of the compounds of Formula I are also included as a part of the present invention.
The base salts may be generated from compounds of Formula I by reaction of the latter with one equivalent of a suitable nontoxic, pharmaceutically acceptable base followed by evaporation of the solvent employed for the reaction and recrystallization of the salt, if required. The compounds of Formula I may be recovered from the base salt by reaction of the salt with an aqueous solution of a suitable acid such as hydrobromic, hydrochloric, or acetic acid.
Suitable bases for forming base salts of the compounds of this invention include amines such as triethylamine or dibutylamine, or alkali metal bases and alkaline earth metal bases. Preferred alkali metal hydroxides and alkaline earth metal hydroxides as salt formers are the hydroxides of lithium, sodium, potassium, magnesium, or calcium. The class of bases suitable for the formation of nontoxic, pharmaceutically acceptable salts is well known to practitioners of the pharmaceutical formulation arts. See, for example, Berge SN, et al, J Pharm Sci 1977;66:1-19.
Suitable acids for forming acid salts of the compounds of this invention containing a basic group include, but are not necessarily limited to acetic, benzoic, benzenesulfonic, tartaric, hydrobromic, hydrochloric, citric, fumaric, gluconic, glucuronic, glutamic, lactic, malic, maleic, methanesulfonic, pamoic, salicylic, stearic, succinic, sulfuric, and tartaric acids. The acid addition salts are formed by procedures well known in the art.
The compounds of the present invention may also exist in different stereoisomeric forms by virtue of the presence of asymmetric centers in the compound. The present invention contemplates all stereoisomeric forms of the compounds as well as mixtures thereof, including racemic mixtures.
Further, the compounds of this invention may exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol and the like. In general, the solvated forms are considered equivalent to the unsolvated forms for the purposes of this invention.
Preferred compounds of the present invention are those wherein one of R 1 and R 2 is phenyl, and more preferably wherein one of R 1 and R 2 is substituted phenyl, and still more preferably wherein one of R 1 and R 2 is phenyl disubstituted in the 2,6-positions.
In one preferred embodiment both R 1 and R 2 are phenyl disubstituted in the 2,6-positions. In another preferred embodiment R 1 is phenyl disubstituted in the 2,6-position and R 2 is trisubstituted in the 2,4,6 -positions.
In another preferred embodiment of the present invention, R 1 is 2,6-bis(1-methylethyl)phenyl; and R 2 is 2,6-bis(1-methylethyl)phenyl or 2,4,6-tris(1-methylethyl)phenyl.
Preferred compounds of Formula I include, but are not limited to the following:
Sulfamic acid (phenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [[2,4,6-tris(1-methylethyl)phenyl]acetyl-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [[2,4,6-tris(1-methylethyl)phenyl]acetyl-2,4,6-tris(1-methylethyl)phenyl ester,
Sulfamic acid [[2,6-bis(1-methylethyl)phenyl]acetyl]-2,4,6-tris(1-methylethyl)phenyl ester,
Sulfamic acid[adamantaneacetyl]-2,6-bis[1-methylethyl)phenyl ester
Sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester-sodium salt,
Sulfamic acid[[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester-sodium salt,
Sulfamic acid (decanoyl)-2,6-bis-(1-methylethyl)phenyl ester,
Sulfamic acid (dodecanoyl)-2,6-bis-(1-methylethyl)phenyl ester,
2,6-Bis(1-methylethyl)-N-[[[2,4,6-tris(1-methylethyl)phenyl]methyl]sulfonyl]benzeneacetamide,
2,6-Bis(1-methylethyl)-N-[[[2,4,6-tris(1-methylethyl)phenyl]methyl]sulfonyl]benzeneacetamide-sodium salt,
2,6-Bis(1-methylethyl)phenyl[[[2,4,6-tris(1-methylethyl)phenyl]methyl]sulfonyl]carbamate,
2,6-Bis(1-methylethyl)phenyl[[[2,4,6-tris(1-methylethyl)phenyl]methyl]sulfonyl]carbamate-sodium salt,
Sulfamic acid (1-oxo-3,3-diphenylpropyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2,6-dichlorophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2,6-dichlorophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid trans-[(2-phenylcyclopropyl)-carbonyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2,5-dimethoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2,4,6-trimethoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2,4,6-trimethylphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2-thiophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [3-thiophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2-methoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (oxophenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [2-trifluoromethylphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (1-oxo-2-phenylpropyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (cyclopentylphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (cyclohexylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (diphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (triphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [(1-phenylcyclopentyl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (3-methyl-1-oxo-2-phenylpentyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (1-oxo-2-phenylbutyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (cyclohexylphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (1-oxo-2,2-diphenylpropyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [(9H-fluoren-9-yl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (1-oxo-3-phenylpropyl)-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [1-oxo-3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [1-oxo-3-[2,4,6-tris(1-methylethyl)phenyl]propyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [(acetyloxy)[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [hydroxy[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [fluoro[2,4,6-tris(1methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid (3-methyl-1-oxo-2-phenylpentyl)-2,6-bis(1-methylethyl)phenyl ester sodium salt,
Sulfamic acid [[2,4,6-tris(1-methylethyl)phenoxy]acetyl]-2,6-bis(1-methylethyl)phenyl ester,
Sulfamic acid [[2,6-bis(1-methylethyl)phenoxy]acetyl]-2,6-bis(1-methylethyl)phenyl ester, and
Sulfamic acid [[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(phenyl)phenyl ester.
As shown by the data presented below in Table 1, the compounds of the present invention are inhibitors of the enzyme acyl-CoA:cholesterol acyltransferase (ACAT), and are thus effective in inhibiting the esterification and transport of cholesterol across the intestinal cell wall. The compounds of the present invention are thus useful in pharmaceutical formulations for the treatment of hypercholesterolemia or atherosclerosis.
The ability of representative compounds of the present invention to inhibit ACAT was measured using an in vitro test more fully described in Field FJ, Salone RG, Biochemica et Biophysica, 1982;712:557-570. The test assesses the ability of a test compound to inhibit the acylation of cholesterol by oleic acid by measuring the amount of radiolabeled cholesterol oleate formed from radiolabeled oleic acid in a tissue preparation containing rat liver microsomes.
The data appear in Table 1 where they are expressed in IC 50 values; i.e., the concentration of test compound required to inhibit the activity of the enzyme by 50%.
TABLE 1______________________________________ LAI Example IC.sub.50 (μM)______________________________________ 1 9.7 2 12 3 11 4 13 5 12 6 12 7 47 8 21 10 >5 11 >10 13 25 14 33 15 34 16 36 17 >50 18 22 19 >50 20 >50 21 55 22 50 23 12 24 26 25 7.2 26 28 27 12 28 6 29 15 30 4.1 31 3.3 32 8.9 33 9.3 34 7.7 35 8.9 36 22 37 16 38 31 39 32 40 32 41 28 42 7 43 31 44 9.4 45 5.6 46 34 47 38 48 8.3______________________________________
In one in vivo screen designated APCC, male Sprague-Dawley rats (200 to 225 g) were randomly divided into treatment groups and dosed at 4 PM with either vehicle (CMC/Tween) or suspensions of compounds in vehicle. The normal chow diet was then replaced with a high fat, high cholesterol diet (designated PCC) containing 0.5% cholic acid. The rats consumed this diet ad libitum during the night and were sacrificed at 8 AM to obtain blood samples for cholesterol analysis using standard procedures. Statistical differences between mean cholesterol values for the same vehicle were determined using analysis of variance followed by Fisher's least significant test. The results of this trial for representative compounds of the present invention appear in Table 2.
TABLE 2______________________________________Compound of % ChangeExample (mg/dl)______________________________________ 1 -63 2 -62 3 -79 4 -47 5 -73 6 -75 7 -17 8 -6610 -2611 -812 -513 -3114 -1215 -1416 +1017 -4018 -4719 -2020 -1921 -1622 -2323 -1924 -2425 -7126 -2627 -7228 -3029 -930 -4031 -3032 -4833 -6334 -6735 -936 -637 -5038 -1639 +540 -5441 -7342 -2543 -4544 -7445 -6346 -5747 -4648 -73______________________________________
In therapeutic use as agents for treating hypercholesterolemia or atherosclerosis, the compounds of Formulas I or II or pharmaceutically acceptable salts thereof are administered to the patient at dosage levels of from 250 to 3000 mg per day. For a normal human adult of approximately 70 kg of body weight, this translates into a dosage of from 5 to 40 mg/kg of body weight per day. The specific dosages employed, however, may be varied depending upon the requirements of the patient, the severity of the condition being treated, and the activity of the compound being employed. The determination of optimum dosages for a particular situation is within the skill of the art.
For preparing the pharmaceutical compositions from the compounds of this invention, inert, pharmaceutically acceptable carriers can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, and cachets.
A solid carrier can be one or more substances which may also act as diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, or tablet disintegrating agents; it can also be an encapsulating material.
In powders, the carrier is a finely divided solid which is in a mixture with the finely divided active component. In tablets, the active component is mixed with the carrier having the necessary binding properties in suitable proportions and compacted in the shape and size desired.
Powders and tablets preferably contain between about 5% to about 70% by weight of the active ingredient. Suitable carriers are magnesium dicarbonate, magnesium stearate, talc, lactose, sugar, pectin, dextrin, starch, tragacanth, methyl cellulose, sodium carboxymethyl cellulose, a low-melting wax, cocoa butter, and the like.
The term "preparation" is intended to include the formulation of the active compound with encapsulating material as a carrier providing a capsule in which the active component (with or without other carriers) is surrounded by a carrier, which is thus in association with it. In a similar manner cachets or transdermal systems are also included.
Tablets, powders, cachets, and capsules can be used as solid dosage forms suitable for oral administration.
Liquid form preparations include solutions, suspensions, or emulsions suitable for oral administration. Aqueous solutions for oral administration can be prepared by dissolving the active compound in water and adding suitable flavorants, coloring agents, stabilizers, and thickening agents as desired. Aqueous suspensions for oral use can be made by dispersing the finely divided active component in water together with a viscous material such as natural or synthetic gums, resins, methyl cellulose, sodium carboxymethylcellulose, and other suspending agents known to the pharmaceutical formulation art.
Preferably, the pharmaceutical preparation is in unit dosage form. In such form, the preparation is divided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation containing discrete quantities of the preparation, for example, packeted tablets, capsules, and powders in vials or ampoules. The unit dosage form can also be a capsule, cachet, or tablet itself, or it can be the appropriate number of these packaged forms.
Some of the preferred compounds of the present invention are prepared as set forth in Chart I hereof wherein R, R 1 and R 2 have the meanings defined in Formula I; and Z represents a halogen.
In Route 1, a solution of a halide of the Formula R 2 Z in ether is added to a suspension of Li powder in ether heated under reflux. The solution is cooled to 0° C. The resulting lithium compound is then poured into the liquid ethylene oxide precooled to -78° C. The mixture is allowed to warm up to room temperature. After work-up with saturated NH 4 Cl, the product (3) is extracted with ethyl acetate. The alcohol (3) is oxidized to the acid (4) by Jones reagent (K 2 Cr 2 O 7 /H 2 SO 4 ) in acetone at 0° C.
Alternatively, the acid (4) can be arrived at using a method similar to Org. Syn, Coll., 3:557 in which a substituted benzene is chloromethylated followed by replacement of the chlorine with nitrile and subsequent hydrolysis of the nitrile to the acid (4).
The acid (4) is then allowed to react with oxalyl chloride in toluene at room temperature to give acyl chloride (5). Meanwhile, alcohol (6) is treated with chlorosulfonyl isocyanate in refluxing toluene to give Compound 7, which is then hydrolysed with water to give Compound 8. Compounds 5 and 8 are then mixed in THF in the presence of Et 3 N at room temperature to give Compound 9. In Route 1A, Compound 9 is also obtained by reacting Compound 7 with R 2 CH 2 MgZ (15) (commercially available or easily prepared through methods generally known in the art) in THF under reflux. Compound 28 is obtained by subsequently treating Compound 9 (as arrived at by either Route 1 or 1A) with base and then RZ.
Other compounds of the present invention are prepared as set forth in Chart II (Routes 2 and 3), hereof wherein R, R 1 and R 2 have the meanings defined in Formula I; and Z represents a halogen.
In Route 2, a solution of halide (R 1 CH 2 Z) (14) and thiourea (Compound 24) in absolute ethanol was heated under reflux to give an isothiourea (R 1 CH 2 --S--C(NH)NH 2 ) (25). Chlorine gas was bubbled through a suspended solution of the isothiourea in H 2 O at 0° C., followed by NH 3 (g) to give the sulfonamide (R 1 CH 2 SO 2 NH 2 ) (18). Condensation between the sulfonamide (18) and an acyl chloride (R 2 CH 2 COCl) (5) in THF under N 2 in the presence of Et 3 N gives an N-acyl sulfonamide (Compound 21). Compound 18 is also allowed to react with Compound 22 (see Route 3 for preparation of Compound 22) in THF in the presence of Et3N at room temperature to give Compound 23. Compound 28 is obtained by subsequently treating Compounds 21 or 23 (as arrived at by Routes 2 or 3, respectively) with a base and then RZ.
The halides RZ, R 2 Z, and R 1 Z used in preparing the compounds of this invention are known in the art or prepared by procedures generally known in the art.
Whereas the preferred compounds of the present invention are prepared as set forth in Charts I and II, it should be understood that the compounds of the present invention can be prepared as set forth generally as follows.
N-acyl sulfamic acid esters (or thioesters) having the formula of Compound 9 in Chart I Route 1 can be prepared by reacting an acyl chloride and a sulfamate having the formula of Compounds 5 and 8, respectively, in Route 1. The resulting ester (or thioester) can optionally be reacted with a base, followed by an aryl halide.
Alternatively, N-acyl sulfamic acid esters (or thioesters) having the formula of Compound 9 in Chart I Route 1A can be prepared by reacting an oxysulfonyl isocyanate and a grignard agent having the formula of Compounds 7 and 15, respectively, in Route 1A. The resulting ester (or thioester) can optionally be reacted with a base, followed by an aryl halide.
N-acyl sulfonamides having the formula of Compound 21 in Chart II Route 2 can be prepared by reacting an acid chloride and a sulfonamide having the formula of Compounds 5 and 18, respectively, in Route 2. The resulting sulfonamide can optionally be reacted with a base, followed by an aryl halide.
N-sulfonyl carbamic acid esters (or thioesters) having the formula of Compound 23 in Chart II Route 3 can be prepared by reacting a sulfonamide and a chloroformate having the formula of Compounds 18 and 22, respectively, in Route 3. The resulting ester (Or thioester) can optionally be reacted with a base, followed by an aryl halide.
EXAMPLES
The following examples illustrate techniques discovered by the inventors for the preparation of the compounds of the present invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent laboratory techniques discovered bythe inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for this practice. Those of skill in the art should, however, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments whichare disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention. In other words, the following examples are given to illustrate particular compositions and methods within the scope of the present invention and are not intended to limit the scope of the present invention.
EXAMPLE 1
Synthesis of sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
(a) 2,6-Diisopropylphenylethanol
2,6 diisopropylbromobenzene (see J. Org. Chem., 42(14):2426-2431 (1977) forpreparation) (30 g, 124.4 mmol) was added to a suspension of Li powder (1.9g, 273.6 mmol) in ether (100 mL) heated under reflux, the heating was continued for another 4 hours, cooled, and the mixture was poured into ethylene oxide which was precooled to -78° C. The mixture was warmed slowly to room temperature, saturated NH 4 Cl solution was added slowly with caution, the ether layer was separated and washed with brine, dried over MgSO 4 , filtered, and the solvent was evaporated to dryness. After column chromatography (3:1 hexane:ethyl acetate) pure 2,6-diisopropylphenylethanol was obtained (17 g, 6.3%); NMR (CDCl 3 ): δ 1.2-1.3 (m, 12H) , 3.05 (t, 2H), 3.15-3.35 (m, 2H), 3.7-3.8 (t, 2H), 7.1-7.3 (m, 3H) ppm.
(b) 2,6-Diisopropylacetic Acid
Jones reagent (94 mL, 2 M, 188 mmol) was added to a solution of 2,6-diisopropylphenylethanol (19.2 g, 93.05 mmol) in acetone (600 mL) at 0° C. over 2 hours. The mixture was stirred for another 0.5 hour. The reaction mixture was poured into ether (1 L) , washed with brine, and the product was extracted by 1N NaOH. The basic extract was acidified withconcentrated HCl, the liberated acid was removed by ether extraction (200 mL×5). The combined ether extract was dried over MgSO 4 , filtered, and then evaporated. The residue was used for the next step without further purification (18.47 g, 90%); NMR (CDCl 3 ): δ 1.15-1.35 (m, 12H), 3.05-3.25 (m, 2H), 3.85 (s, 2H), 7.1-7.35 (m, 3H) ppm.
(c) Sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
2,6-Diisopropylacetic acid (200 mg, 0.91 mmol) and oxalyl chloride (253.9 mg, 2 mmol) were mixed together in 20 mL of toluene at room temperature under N 2 with a few drops of DMF as catalyst. The mixture was stirredfor 16 hours, the solvent and the excess oxalyl chloride were then removed in vacuo, and the acyl chloride was redissolved in 20 mL of dry THF. 2,6-Diisopropylphenyl sulfamate (257 mg, 1 mmol, see Phos. and Sulf., 19:167 (1984) for preparation) and Et 3 N (139 μL, 1 mmol) were added to the solution under N 2 and the mixture was stirred at room temperature for 3 hours. The solvent was removed and the residue was distributed between ethyl acetate and 1N HCl. The organic layer was dried over MgSO 4 , filtered, and evaporated, and the pure product was isolated by column chromatography (1:1 hexane:EtOAc, 300 mg, 72%), mp 166°-168° C.
EXAMPLE 2
Synthesis of sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester sodium salt
The sodium salt of the title compound of Example 1 was prepared by dissolving the title compound of Example 1 (1 g, 2.18 mmol) in THF (10 mL), and one equivalent of NaH (87 mg, 2.18 mmol) was added to the solution and this was then stirred for 0.5 hour. The solvent was evaporated and product was obtained by trituration with hexane (0.63 g, 60%), mp 242°-244° C.
EXAMPLE 3
Synthesis of sulfamic acid[[2,6-bis(1-methylethyl)phenyl]acetyl]-2,4,6-tris(1-methylethyl)phenylester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisoproplyphenyl sulfamate was replaced with 2,4,6-triisoproplyphenyl sulfamate, mp 152°-155° C.
EXAMPLE 4
Synthesis of sulfamic acid[adamantaneacetyl]-2,6-bis[1-methylethyl]phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetyl chloride was replaced with adamantaneacetyl chloride; 1 H NMR(CDCl 3 ): 1.21 (d, 12H), 1.6-2.0 (m, 15H), 2.15 (s, 2H), 3.4 (m, 2H), 7.15-7.25 (m, 3H) ppm.
EXAMPLE 5
Synthesis of Sulfamic acid[[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenylester
(a) 2,4,6-Triisopropylbenzyl alcohol
A solution of commercially available 2,4,6-triisopropylbenzoyl chloride (35g, 131.2 mmol) in 400 mL ether was added slowly to a suspension of lithium aluminum hydride (LAH) (4.89 g, 131.2 mmol) in ether (300 mL) at -15° C. The mixture was slowly warmed to room temperature over 18 hours. Saturated Na 2 SO 4 solution was added slowly and the etherlayer was separated, dried over MgSO 4 , and evaporated to dryness. The compound was used in the next step without further purification; NMR (CDCl 3 ): δ 1.2-1.4 (m, 18H), 2.8-3.0 (m, 1H), 3.3-3.5 (m, 2H), 4.8 (s, 2H), 7.1 (s, 2H) ppm.
(b) 2,4,6-Triisopropylbenzyl bromide
A solution of PBr 3 (2.7 g, 10 mmol) in ether (10 mL) was added slowly to a solution of 2,4,6-triisopropylbenzyl alcohol (4.68 g, 20 mmol) in 20 mL of ether at room temperature. The mixture was stirred for 1 hour, 5 mL of absolute EtOH was added, and stirring was continued for another 0.5 hour. The solvent was removed and the residue distributed between EtOAc and saturated Na 2 CO 3 . The EtOAc layer was separated, washed with brine, and dried over MgSO 4 . The solvent was evaporated and the pure product was isolated by column chromatography (100% CH 2 Cl 2 , 3.5 g, 59%); NMR (CDCl 3 ): δ 1.2-1.4 (m, 18H), 2.8-3.0(m, 1H), 3.2-3.45 (m, 2H), 4.7 (s, 2H), 7.04 (s, 2H) ppm.
(c) Sulfamic acid [2,4,6-tris(1-methylethyl)phenyl]acetyl]2,6-bis(1-methylethyl)phenyl ester
A solution of 2,4,6 - triisopropylbenzyl bromide (12 g, 40.4 mmol) in dry THF (160 mL) was added to a suspension of Mg powder (1.96 g, 80.8 mmol) (4hours) in THF (20 mL) heated under reflux. 2,6-Diisopropylphenoxysulfonyl isocyanate (ROSO 2 NCO) (see Phos. and Sulf., 19:167 (1984) for preparation) (11.45 g, 40.4 mmol) was added neat, and after the addition was completed, the reflux was continued for another 2 hours. The reaction was stirred at room temperature for 16 hours. Saturated NH 4 Cl and EtOAc were added. The EtOAc layer was separated, dried over MgSO 4 , filtered, and evaporated to dryness. After purification by column chromatography (4:1 hexane:EtOAc), the compound was isolated as white solid (13.5 g, 67%), mp 178°-180° C.
EXAMPLE 6
Synthesis of sulfamic acid[[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenylester sodium salt
This compound was prepared in the same manner as for the title compound of Example 2, except that the title compound of Example 1 was replaced with the title compound of Example 5, mp 250°-252° C.
EXAMPLE 7
Synthesis of sulfamic acid(phenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as the title compound of Example 5, except that 2,4,6-triisopropylbenzyl magnesium bromide was replaced with benzylmagnesium chloride (commercially available), mp 150°-152° C.
EXAMPLE 8
Synthesis of sulfamic acid[[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,4,6-tris(1-methylethyl)phenyl ester
This compound was prepared in the same manner as the title compound of Example 5, except that 2,6-diisopropylphenoxy sulfonyl isocyanate was replaced with 2,4,6-triisopropylphenoxy sulfonyl isocyanate, mp 178°-180° C.
EXAMPLE 9
Synthesis of 2,6-Bis(1-methylethyl)-N-[[[2,4,6-tris(1-methylethyl)phenyl]methyl]sulfonyl]benzeneacetamide
(a) S-2,4,6-Triisopropylbenzyliosthiourea
A mixture of 2,4,6-triisopropylbenzyl bromide (6.0 g, 20 mmol) and thiourea(1.536 g, 20.1 mmol) in 180 mL of absolute EtOH was heated under reflux for3 hours. The reaction was cooled and evaporated. The white powder (7.1 g, 95%) was used for next step without further purification, mp 200°-205° C.
(b) 2,4,6-Triisopropylbenzylsulfonamide
Chlorine gas was bubbled through a suspension of S-2,4,6-triisopropylbenzylisothiourea hydrobromide (2.5 g, 8.56 mmol) in H 2 O (100 mL) at 0° C. for 1 hour. The solid was extracted into EtOAc (50 mL) and NH 3 (g) was bubbled through the EtOAc solution at 0° C. for 0.5 hour and the solution was further stirred at room temperature for 2 hours. 2,4,6-Triisopropylbenzylsulfonamide was isolated as white powder (100 mg) by column chromatography (4:1 hexane:EtOAc); NMR (CDCl 3 ): δ 1.2-1.6 (m, 18H), 2.8-3.0 (m, 2H), 3.25-3.4 (m, 2H),4.75 (s, 2H), 7.0 (s, 2H), ppm.
(c) 2,6-Bis(1-methylethyl)-N-[[[2,4,6-tris(1-methylethyl)-phenyl]methyl]sulfonyl]benzeneacetamide
A solution of 2,4,6-triisopropylbenzylsulfonamide (100 mg, 0.33 mmol), 2,6-diisopropylphenylacetyl chloride (75 mg, 0.34 mmol), and Et 3 N (47 μL, 0.34 mmol) in 10 mL THF was stirred at room temperature overnight. The solvent was evaporated and the residue was distributed between ethyl acetate and 0.1N HCl, the organic layer was washed with brine, dried, and evaporated. The pure product (20 mg, 12%) was isolated by column chromatography (4:1 hexane:EtOAc), m/e=499; NMR (CDCl 3 ): δ 7.05-7.4 (m, 5H), 4.25 (s, 2H), 3.95 (s, 2H), 3.45-3.6 (m, 1H), 3.0-3.15 (m, 2H), 2.85-3.0 (m, 2H), 1.05-1.4 (m, 30H) ppm.
EXAMPLE 10
Synthesis of sulfamic acid (decanoyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetyl chloride was replaced with decanoyl chloride, mp 92°-94° C.
EXAMPLE
Synthesis of sulfamic acid(dodecanoyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetyl chloride was replaced with dodecanoyl chloride; 1 H NMR (DMSO-26): δ 7.09 (s, 3H), 3.65 (heptet, 2H), 2.05 (t, 2H), 1.48-1.15 (m, 18H); 1.10 (d, 6H), 0.86 (t, 3H) ppm.
EXAMPLE 12
Synthesis of sulfamic acid[1-adamantyl(carbonyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 1-adamantecarboxylic acid, mp 165°-167° C.
EXAMPLE 13
Synthesis of sulfamic acid(1-oxo-3,3-diphenylpropyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 3,3-diphenylpropionic acid, mp 149°-152° C.
EXAMPLE 14
Synthesis of sulfamic acid[2,6-dichlorophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2,6-dichlorophenylacetic acid, mp 203°-205° C.
EXAMPLE 15
Synthesis of sulfamic acid trans-[(2-phenylcyclopropyl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with trans-2-phenylcyclopropylcarboxylic acid, mp 166°-168° C.
EXAMPLE 16
Synthesis of sulfamic acid[2,5-dimethoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetyl chloride was replaced with 2,5-dimethoxyphenylacetyl chloride, mp 150°-152° C.
EXAMPLE 17
Synthesis of sulfamic acid[2,4,6-trimethoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2,4,6-trimethoxyphenylacetic acid, mp 159°-163° C.
EXAMPLE 18
Synthesis of sulfamic acid[2,4,6-trimethylphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2,4,6-trimethylphenylacetic acid, mp 159°-161° C.
EXAMPLE 19
Synthesis of sulfamic acid[2-thiophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2-thiopheneacetic acid, mp 133°-136° C.
EXAMPLE 20
Synthesis of sulfamic acid[3-thiophenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 3-thiopheneacetic acid, mp 136°-138° C.
EXAMPLE 21
Synthesis of sulfamic acid[2-methoxyphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2-methoxyphenylacetic acid, mp 159°-161° C.
EXAMPLE 22
Synthesis of sulfamic acid(oxophenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with benzoylformic acid, mp 106°-109° C.
EXAMPLE 23
Synthesis of sulfamic acid[2-trifluoromethylphenyl(acetyl)]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2-trifluoromethylphenylacetic acid, mp 144°-149° C.
EXAMPLE 24
Synthesis of sulfamic acid(1-oxo-2-phenylpropyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2-phenylpropionic acid, mp 142°-144° C.
EXAMPLE 25
Synthesis of sulfamic acid(cyclopentylphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with α-phenylcyclopentanecarboxylic acid, mp 142°-143° C.
EXAMPLE 26
Synthesis of sulfamic acid(cyclohexylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with cyclohexylacetic acid; 1 H NMR (CDCl 3 ): δ 8.35 (s, 1H), 7.1-7.3 (m, 3H), 3.3-3.45 (m, 2H), 2.35 (d, 2H), 1.55-1.95 (m, 8H), 1.22 (d, 12H) , 0.9-1.1 (m, 2H), ppm.
EXAMPLE 27
Synthesis of sulfamic acid(diphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with diphenylacetic acid, mp 164°-166° C.
EXAMPLE 28
Synthesis of sulfamic acid(triphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with triphenylacetic acid, mp 142°-144° C.
EXAMPLE 29
Synthesis of sulfamic acid[(1,2,3,4-tetrahydro-2-naphthyl)carbonyl]-2,6-bis(1-methylethyl)phenylester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 1,2,3,4-tetrahydro-2-naphthoic acid, mp 137°-139° C.
EXAMPLE 30
Synthesis of sulfamic acid[(1-phenylcyclopentyl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 1-phenyl-1-cyclopentanecarboxylic acid, mp 149°-152° C.
EXAMPLE 31
Synthesis of sulfamic acid(3-methyl-1-oxo-2-phenylpentyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 3-methyl-2-phenylvaleric acid; 1 H NMR (CDCl 3 ): δ 8.65 (bs, 1H), 7.36-7.11 (m, 8H), 3.35-3.21 (m, 3H), 2.18 (bs, 1H), 1.73-0.69 (m, 20H), ppm.
EXAMPLE 32
Synthesis of sulfamic acid(1-oxo-2-phenylbutyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetyl chloride was replaced with 2-phenylbutyryl chloride, mp 142°-145° C.
EXAMPLE 33
Synthesis of sulfamic acid(cyclohexylphenylacetyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with α-phenylcyclohexanecarboxylic acid, mp 127°-137° C.
EXAMPLE 34
Synthesis of sulfamic acid(1-oxo-2,2-diphenylpropyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 2,2-diphenylpropionic acid, mp 140°-145° C.
EXAMPLE 35
Synthesis of sulfamic acid[bis-(4-chlorophenyl)acetyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with bis(4-chlorophenyl)acetic acid, mp 175°-176° C.
EXAMPLE 36
Synthesis of sulfamic acid[(9H-xanthen-9-yl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with xanthene-9-carboxylic acid, mp 180°-181° C.
EXAMPLE 37
Synthesis of sulfamic acid[(9H-fluoren-9yl)carbonyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 9-fluorenecarboxylic acid, mp 146°-147° C.
EXAMPLE 38
Synthesis of sulfamic acid(1-oxo-3-phenylpropyl)-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with hydrocinnamic acid, mp 121°-124° C.
EXAMPLE 39
Synthesis of sulfamic acid[bromo(phenyl)acetyl]-2,6l-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with α-bromophenylacetic acid, mp 155°-159° C.
EXAMPLE 40
Synthesis of sulfamic acid[1-oxo-3-[2,4,6-tris-(1-methylethyl)phenyl]-2-propenyl]-2,6-bis-(1-methylethyl)phenyl ester
(a) 3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid, methyl ester
A mixture of methyl acrylate (15.9 mL, 176 mmol) and bis(triphenylphosphine)palladium (II) chloride (0.99 g, 1.4 mmol) in 125 mL dimethylformamide and 125 mL triethylamine was heated to reflux for 1 hour and then 2,4,6-triisopropylbromobenzene (10.0 g, 35 mmol) was added. Reflux was continued for 6 hours and then stirred at room temperature for 16 hours. Partitioned the reaction between water and diethyl ether. The ether layer was dried with MgSO 4 , filtered, and concentrated to give a brown oil. Chromatography (SiO 2 , eluant=5% ethyl acetate in hexanes) gave 3.80 g of 3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid, methyl ester as an off-white solid, mp 61°-63° C.
(b) 3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid
Sodium hydroxide (0.23 g, 5.7 mmol) was added to a solution of 3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid, methyl ester (1.5 g, 5.2 mmol) in 100 mL methanol and 10 mL water. Stirred at room temperature for 48 hours and concentrated to dryness. Partitioned theresidue between water and diethyl ether. The aqueous layer was acidified with concentrated HCl and extracted with dichloromethane. The organic extract was dried over MgSO 4 , filtered, and concentrated to give 1.33g of 3-[2,4,6-tris-(1-methylethyl)phenyl]-2-propenyl carboxylic acid as a white solid, mp 201°-203° C.
(c) Sulfamic acid[1-oxo-3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid, mp 144°-148° C.
EXAMPLE 41
Synthesis of sulfamic acid[1-oxo-3-[2,4,6-tris(1-methylethyl)phenyl]propyl]-2,6-bis(1-methylethyl)phenyl ester
(a) 3-[2,4,6-tris(1-methylethyl)phenyl]propionic acid, methyl ester
3-[2,4,6-tris(1-methylethyl)phenyl]-2-propenyl carboxylic acid, methyl ester (2.20 g, 7.6 mmol, from Example 40 (a)) was dissolved in 100 mL methanol. 0.5 g of 20% palladium on carbon was added and the mixture was charged with 50 psi of hydrogen gas. After 5 hours at room temperature, the reaction was filtered and concentrated to give 2.37 g of 3-[2,4,6-tris(1-methylethyl)phenyl]propionic acid, methyl ester as an off-white solid, mp 45°-47° C.
(b) 3-[2,4,6-tris(1-methylethyl)phenyl]propionic acid
3-[2,4,6-Tris(1-methylethyl)phenyl]propionic acid, methyl ester (2.12 g, 7.3 mmol) was dissolved in 100 mL methanol and 10 mL water. Sodium hydroxide (0.32 g, 8.0 mmol) was added and the resulting solution was stirred at room temperature for 4 hours. Concentrated in vacuo and partitioned the residue between water and diethyl ether. The aqueous layerwas acidified with concentrated HCl and extracted with dichloromethane. Theorganic extract was dried over MgSO 4 , filtered, and concentrated to give 1.87 g of 3-[2,4,6-tris(1-methylethyl)phenyl]propionic acid as a white solid, mp 194°-196° C.
(c) Sulfamic acid[1-oxo-3-[2,4,6-tris(1-methylethyl)phenyl]propyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with 3-[2,4,6-tris(1-methylethyl)phenyl]propionic acid, mp 138°-141° C.
EXAMPLE 42
Synthesis of sulfamic acid[(acetyloxy)[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
(a) Acetyloxy[2,4,6-tris(1-methylethyl)phenyl]acetic acid
Glyoxylic acid (1.99 g, 27 mmol) and 1,3,5-triisopropylbenzene (5.0 g, 24.5mmol) were mixed in 30 mL glacial acetic acid and 2 mL concentrated sulfuric acid. The resulting solution was heated to reflux for 5 hours andthen stirred at room temperature for 16 hours. The reaction mixture was poured into 100 g ice and the resulting mixture was extracted with diethylether. The organic layer was dried over MgSO 4 , filtered, and concentrated to give an oily solid which was recrystallized from hexanes to give 3.29 g of acetyloxy[2,4,6-tris(1-methylethyl)phenyl]acetic acid, mp 166°-169° C.
(b) [(Acetyloxy)[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with acetyloxy[2,4,6-tris(1-methylethyl)phenyl]acetic acid, mp 140°-146° C.
EXAMPLE 43
Synthesis of sulfamic acid[hydroxy[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
[(Acetyloxy)[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester (1.50 g, 2.7 mmol) was dissolved in 75 mL methanol and 25 mL water. Sodium hydroxide (0.22 g, 5.5 mmol) was added and the resulting solution was stirred at room temperature for 16 hours. Concentrated in vacuo, redissolved the residue in water, acidified to pH 4.0 with concentrated HCl and extracted with diethyl ether. The organic extract wasdried over MgSO 4 , filtered, and concentrated to give an oil. Triturated with hexanes to give 0.56 g of sulfamic acid [hydroxy[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester, mp 96°-101° C.
EXAMPLE 44
Synthesis of sulfamic acid[fluoro[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester
[Hydroxy[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester (0.73 g, 1.4 mmol) was dissolved in 20 mL dichloromethane and added dropwise to a solution of diethylaminosulfur trifluoride (0.19 mL, 1.4 mmol) in 10 mL dichloromethane at -8° C. Gradually warmed to room temperature and stirred for 16 hours. Concentrated in vacuo and partitioned the residue between water and ethyl acetate. The organic extract was dried over MgSO 4 , filtered, and concentrated to give a yellow oil. Triturated with hexanes to give 0.39 g of sulfamic acid [fluoro[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(1-methylethyl)phenyl ester, mp 130°-132° C.
EXAMPLE 45
Synthesis of sulfamic acid(3-methyl-1-oxo-2-phenylpentyl)-2,6-bis(1-methylethyl)phenyl ester sodium salt
This compound was prepared in the same manner as for the title compound of Example 2, except that the title compound of Example 1 was replaced with the title compound of Example 31, mp 275°-277° C.
EXAMPLE 46
Synthesis of sulfamic acid[[2,4,6-tris(1-methylethyl)phenoxy]acetyl]-2,6-bis(1-methylethyl)phenyl ester
(a) [2,4,6-tris(1-methylethyl)phenoxylacetic acid
A solution of 2,4,6-triisopropylphenol (4.0 g, 18 mmol) in 50 mL tetrahydrofuran was added dropwise to a suspension of sodium hydride (1.52g, 38 mmol) in 25 mL tetrahydrofuran. The resulting pale green suspension was stirred for 30 minutes before a solution of bromoacetic acid (2.52 g, 18 mmol) in 50 mL tetrahydrofuran was added dropwise. The resulting thick suspension was stirred for 16 hours and then concentrated in vacuo. The residue was partitioned between 1N HCl and dichloromethane, the organic extract was dried over MgSO 4 , filtered, and concentrated to give a yellow solid. Recrystallized from hexanes to give 3.1 g of [2,4,6-tris(1-methylethyl)phenoxy]acetic acid, mp 105°-108° C.
(b) Sulfamic acid[[2,4,6-tris(1-methylethyl)phenoxy]acetyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenylacetic acid was replaced with [2,4,6-tris(1-methylethyl)phenoxy]acetic acid, mp 126°-128° C.
EXAMPLE 47
Synthesis of sulfamic acid[[2,6-bis(1-methylethyl)phenoxy]acetyl]-2,6-bis(1-methylethyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 46, except that 2,4,6-triisopropylphenol was replaced with 2,6-diisopropylphenol, mp 108°-110° C.
EXAMPLE 48
Synthesis of sulfamic acid[[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(phenyl)phenyl ester
(a) 2,6-Bis(phenyl)phenyl sulfamate
A solution of chlorosulfonyl isocyanate (5.57 mL, 64 mmol) in 50 mL toluenewas added dropwise to a solution of 2,6-diphenylphenol (15.0 g, 61 mmol) in200 mL toluene at 50° C. The resulting white suspension was heated to reflux for 16 hours. Concentrated in vacuo and carefully partitioned the residue between water and diethyl ether. The ether layer was dried over MgSO 4 , filtered, and concentrated to give an off-white solid. Recrystallized from hexanes to give 2,6-bis(phenyll)phenyl sulfamate as a white solid, mp 145°-147° C.
(b) Sulfamic acid [[2,4,6-tris(1-methylethyl)phenyl]acetyl]-2,6-bis(phenyl)phenyl ester
This compound was prepared in the same manner as for the title compound of Example 1, except that 2,6-diisopropylphenyl sulfamate was replaced with 2,6-bis(phenyl)phenyl sulfamate, mp 129°-132° C. ##STR5## | The present invention is directed to compounds useful for the regulation of cholesterol of Formula I, methods for using them and pharmaceutical compositions thereof, ##STR1## wherein X and Y are oxygen, sulfur, or (CR'R") n wherein n is 1 to 4; R is hydrogen, alkyl, or benzyl; R 1 and R 2 are phenyl, substituted phenyl, naphthyl, substituted naphthyl, an aralkyl group, an alkyl chain, adamantyl, or a cycloalkyl group. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to wet strength resin compositions and a method for making them.
2. Description of the Related Art
Polyamine-epichlorohydrin resins have been used as wet strength resins for paper since the early 1950's. These resins are cationic by virtue of the fact that they contain quaternary ammonium functionalities and are, therefore, substantive to negatively charged cellulose pulp fibers. These resins are particularly useful because they are formaldehyde-free and develop wet strength at neutral or alkaline pH values. The polyamine-epichlorohydrin resins are normally made by reacting epichlorohydrin and a polyamine such as ethylenediamine, triethylenetetramine, bishexamethylenetriamine, and amine still bottoms which is a mixture of polyamines containing from about 35% to about 70% by weight bishexamethylenetriamine. While the reaction is usually carried out in water, U.S. Pat. Nos. 3,894,944; 3,894,945; Re. No. 28, 807; 3,894,946, 3,894,947, disclose that a water soluble alcohol may be used in place of part of the water. However, these patents also disclose that it is generally preferred to use water alone for economic reasons. U.S. Pat. No. 2,595,935 discloses the use of a water miscible solvent such as ethanol. The use of simple alcohols such as methanol and ethanol as cosolvents has been found to be unacceptable when polyamine-epichlorohydrin resin solutions are used as wet strength resin compositions because these alcohols have low flash points and they remain in the final product. It would be desirable, therefore, to use an alcohol that has a flash point high enough for use in commercial paper making operations and one that is not a health and safety hazard to those who handle it or those who use products produced by wet strength formulations containing it.
SUMMARY OF THE INVENTION
The present invention provides a wet strength resin composition comprising from about 48 weight % to about 89 weight % water, from about 1.0 weight % to about 7.0 weight % of at least one polyol, and from about 10 weight % to about 45 weight % of a polyamine-epichlorohydrin resin.
The present invention also provides a method of making a polyamine-epichlorohydrin resin comprising the steps of: (a) providing a water-polyol-polyamine solution; (b) adding to said solution epichlorohhydrin at a rate sufficient to maintain the temperature of said solution in a range of from about 5° C. to about 15° C. to form a reaction mixture having an E/N ratio of from about 1.0 to about 1.4; (c) maintaining the temperature of said reaction mixture in a range of from about 50° C. to about 80° C. until a 35% solids solution of said reaction mixture has a viscosity of at least about 70 cps; and (d) adjusting the pH of said reaction mixture to from about 2 to about 3 with an aqueous acid solution.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One aspect of the present invention provides a wet strength resin composition for increasing the wet strength of cellulosic webs comprising from about 48 weight % to about 89 weight % water, from about 1.0 weight % to about 7.0 weight % of at least one polyol, and from about 10 weight % to about 45 weight % of a polyamine-epichlorohydrin resin.
The wet strength resin composition of the present invention is made by the process disclosed herein where an amine-epichlorohydrin resin is made by reacting a polyamine and epichlorohydrin in an aqueous polyol solution. A polyamine is any amine that has at least two amine functionalities such as a simple diamine as ethylene diamine or more than two amine functionalities such as diethylene triamine, triethylenetetramine, and bishexamethylenetriamine and the like. Preferably, the polyamine is a mixture of polyamines known as amine still bottoms which is a mixture of polyamines containing from about 35% by weight to about 70% by weight bishexamethylenetriamine. It has been found that at least one polyol is a necessary component of the reaction because it performs the dual function of a cosolvent and a moderator of the cross-linking reaction. The polyol component of the wet strength composition can be any aliphatic compound having 2 or more hydroxyl functionalities that is miscible with water or combinations thereof. Examples of such polyols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1,6-hexylene glycol, glycerol, monosaccharides such as glucose or fructose, disaccharides such as sucrose, and polyvinyl alcohol. The preferred polyols are 1,2-propylene glycol and dipropylene glycol because they are generally recognized as safe, have flash points >200° C., and are good cosolvents for the amine-epichlorohydrin reaction. A preferred wet strength resin composition contains about 60.2% by weight water, about 4.8% by weight of 1,2-propylene glycol, and about 35% by weight of a polyamine-epichlorohydrin resin.
Another aspect of the present invention provides a process for making a polyamine-epichlorohydrin resin comprising the steps of: (a) providing a water-polyol-polyamine solution; (b) adding to said solution epichlorohhydrin at a rate sufficient to maintain the temperature of said solution in a range of from about 5° C. to about 15° C. to form a reaction mixture having an E/N ratio of from about 1.0 to about 1.4; (c) maintaining the temperature of said reaction mixture in a range of from about 50° C. to about 80° C. until a 35% solids solution of said reaction mixture has a viscosity of at least about 70 cps; and (d) adjusting the pH of said reaction mixture to from about 2 to about 3 with an aqueous acid solution. The process of the present invention is generally carried out by first preparing a water-polyol-polyamine solution containing from about 41 weight % to about 59 weight % water, from about 10 weight % to about 16 weight % of at least one polyol, from about 31 weight % to about 43 weight % polyamine. It is preferred that the polyamine be an aqueous solution containing about 50% by weight polyamine and having a total alkalinity of from about 33% to about 43%. The resulting water-polyol-polyamine solution is then mixed while cooling to 5° C. until it is a single phase. The epichlorohydrin is then added at a rate sufficient to maintain the temperature of the solution in a range of from about 5° C. to about 15° C., preferably 5° C. to about 10° C. to form a reaction mixture having an E/N ratio of from about 1.0 to about 1.4. The E/N ratio is defined as ##EQU1## The total alkalinity is the number of equivalents of HCl required to neutralize 1.0 gram of polyamine. The E/N ratio can vary from about 1.0 to about 1.4 and is preferably 1.15 to 1.4. The absolute amount of amine+epichlorohydrin can be from about 52% by weight to about 64% by weight of the reaction mixture with about 56%-59% by weight being the preferred amount. The reaction is allowed to proceed in a temperature range of from about 50° C. to about 80° C., preferably from about 60° C. to about 70° C., until a 35% solids solution has a viscosity of at least 70 cps (Brookfield, spindle #2 @ 160 r.p.m., 25° C.). The 35% solids solution is formed by diluting the reaction mixture with water until the non-volatile solids reaches about 35% by weight. The reaction is then quenched by adding water to bring the total solids to about 35% and the pH is adjusted to about 2-3 by addition of aqueous acid preferably 31.5% aqueous HCl.
In a preferred embodiment, a water-polyol-polyamine solution is prepared containing about 141.9 grams of a 51.5% solids amine bottoms solution having a total alkalinity of 36.08%, 32.4 grams of water and 23.8 grams of 1,2-propylene glycol. The Water-polyol-polyamine solution is placed in a reactor, mixed until uniform, and cooled to 5° C. A total of 99.7 grams of epichlorohydrin is then added at a rate sufficient to maintain the reaction temperature between 5°-15° C. The E/N ratio is 1.18. After all the epichlorohydrin is added, the reaction mass is allowed to exotherm freely to 55° C. and held there until the viscosity at 35% solids solution reaches about 82 cps (Brookfield, spindle #2 @ 160 r.p.m., 25° C.). The reaction mass is then quenched by adding water and 31.5% aq. HCl. The pH and the solids of the reaction mass is then adjusted to 3.1 and 35% respectively. The composition has a flash point (PMCC) of >200° F.
The following examples will serve to illustrate but not limit the invention.
EXAMPLE 1
Preparation of polyamine-epichlorohydrin resin-Water-Propylene Glycol Solvent
Added to a suitable reactor was 141.9 parts of an amine bottoms solution having a total alkalinity of 36.08% and a solids content of 51.5%. Also charged were 32.4 parts of water and 23.8 parts of propylene glycol. The contents of the reactor were mixed until uniform, cooled to 5° C., at which time the epichlorohydrin was added over a 12 hour period. The temperature was controlled between 5°- 15° C. during the addition of 81.8 parts of epichlorohydrin. During the last 18 minutes of the epichlorohydrin feed, the cooling was shut-off and 17.9 parts of epichlorohydrin was added. The reaction mass was allowed to exotherm freely to 55° C. The reaction mass was held at 55° C. until the viscosity at 35% solids was 82.5 cps. The reaction mass was quenched by adding water and 31.5% aq. HCl. The pH and the solids of the reaction mass was adjusted to 3.1 and 35% respectively. The flash point (PMCC) of the resin was >200° F.
EXAMPLE 2
Preparation of Polyamine-Epichlorohydrin Resin-Water-Propylene Glycol Solvent
Added to a suitable reactor was 141.9 parts of an amine bottoms solution having a total alkalinity of 34.84% and a solids content of 47.05%. Also charged were 29.9 parts of water and 24.7 parts of propylene glycol. The contents of the reactor were mixed until uniform. The contents of the reactor were cooled to 5° C. at which time the epichlorohdyrin was added over a 12 hour period. The temperature was controlled between 5°-15° C. during the addition of 92.25 parts of epichlorohydrin. During the last 18 minutes of the epichlorohydrin feed, the cooling was shut-off and 20.25 parts of epichlorohydrin was added. The reaction mass was allowed to exotherm freely to 60° C. The reaction mass was held at 60°-65° C. until the viscosity at 35% solids was 85 cps. The reaction mass was quenched by adding water and 31.5 aq. HCl. The pH and the solids of the reaction mass was adjusted to 2.9 and 37% respectively. The flash point (PMCC) of the resin was >200° F.
EXAMPLE 3
Preparation of Polyamine-Epichlorohydrin Resin-Water-Ethylene Glycol Solvent
Added to a reactor was 121.7 parts of an amine bottoms solution having a total alkalinity of 35.62% and a solids contents of 45.1%. Also charged were 10.6 parts of water and 23.4 parts of ethylene glycol. The contents of the reactor were mixed until uniform while cooling to 6.5° C. 84.3 parts of epichlorohydrin was added over 55 minutes while maintaining the temperature between 5°-15° C. Once all the epichlorohydrin was added, the reaction mass was allowed to exotherm to 80° C. The reaction mass was held at 80° C. until the viscosity at 35% solids reached 105 cps. The reaction mass was quenched by adding water and 31.5% aq. HCl. The pH and the solids of the reaction mass was adjusted to 3.0 and 37.6% respectively.
EXAMPLE 4
Preparation of Polyamine-Epichlorohydrin Resin-Water-Hexylene Glycol Solvent
Added to a reactor was 116 parts of an amine bottoms solution having a total alkalinity of 35.62% and a solids content of 50.7%. Also charged were 23.1 parts of water and 20.5 parts of hexylene glycol. The contents of the reactor were mixed until uniform while cooling to 5° C. 80.4 parts of epichlorohydrin was added over 75 minutes while maintaining the temperature between 5°-15° C. Once all the epichlorohydrin was added, the reaction mass was allowed to exotherm to 80° C. The reaction mass was held at 80° C. until the viscosity at 35% solids reached 78 cps. The reaction mass was quenched with water and 31.5% aq HCl. The pH and the solids of the reaction mass was adjusted to 3.0 and 33.5% respectively.
COMPARATIVE EXAMPLE A
This example shows that without the aid of a glycol cosolvent, the reaction mass reacts uncontrollably to yield a water insoluble cross-linked gel.
Preparation of Polyamine-Epichlorohydrin Resin-Water Solvent
Added to a suitable reactor were 80 parts of amine bottoms concentrate and 119 parts of water. The contents of the reactor were mixed together. The % solids and % total alkalinity of the solution was determined as 34.1 and 29.2 respectively. The reaction mass was cooled at 2° C., at which time the epichlorohydrin feed was started. 113 parts of epichlorohydrin was added over a 8.25 hour period while maintaining a temperature of 2°-15° C. Once the epichlorohydrin addition was complete, the cooling was shut-off and the reaction mass freely exothermed to 70° at which point the reaction mass instantly gelled in the reactor.
COMPARATIVE EXAMPLE B
This example shows that a wet strength resin composition comparable to those of Examples 1 and 2 but which contains methanol in place of a glycol has an unacceptable flash point.
Preparation of Polyamine-Epichlorohydrin Resin-Water-Methanol Solvent
Added to a suitable reactor were 80 parts of amine bottoms concentrate, 114.5 parts of water and 33.5 parts of methanol. The contents of the reactor were mixed to form a uniform solution. The % solids and % total alkalinity of the solution was determined as 34.7 and 28.5 respectively. The reaction mass was cooled at 0° C., at which time the epichlorohydrin feed was started. 126 parts of epichlorohydrin was added over a 7.5 hour period while maintaining a temperature of 0°-15° C. Once the epichlorohydrin addition was complete, the cooling was shut-off and the reaction mass freely exothermed to 70°. The reaction mass was held at 70° C. until the viscosity at 35% solids reached 118 cps. The reaction mass was quenched by adding water and concentrated HCl. The pH and solids of the reaction mass was adjusted to 2.8 and 35% respectively. The flash point (PMCC) of the resin was 150° F. | An amine-epichlorohydrin resin is prepared in a water-polyol solvent in order to facilitate the polymerization and crosslinking reactions. The reaction product is useful as a wet strength resin composition which has a flash point high enough to be used in commercial paper making operations. | 3 |
FIELD OF THE INVENTION
[0001] The present disclosure pertains to surface profilometers, and more particularly to a portable optical surface profilometer device, system and method.
BACKGROUND
[0002] Surface roughness is considered to be the statistical measure of a surface's deviation from a perfectly flat plane. While all surface roughness measures go back to this definition, the exact value of the measure can vary heavily based upon the methodology used to calculate it. The direct calculation of all surface roughness measures requires the use of a height map of the sample surface. Height maps of any particular sample can be gathered through the use of a profilometer tool.
[0003] The most common numerical measure of roughness is R a , and it is defined as the average value of the deviation from a linear profile along the sample surface. A similar approach to calculate a roughness value is the S a statistic, which is defined as the average value of the deviation from a flat plane along the sample surface. Other roughness statistics known in the art may also be computed. While roughness statistics most often directly use the height deviation from a perfectly flat sample, there exist other calculations which focus more on the geometric features of the sample. Roughness factor is calculated as the area of the actual sample surface divided by the area of the perfectly flat sample surface.
[0004] Many advanced manufacturing processes require the operator to know the surface roughness statistics of the final product, the manufacturing equipment, or both. The success of the plastic injection molding process, for example, can depend on the quality of mold surfaces that come out of the Computer Numerical Control (CNC) milling process. Surface quality of the mold surfaces is generally characterized in terms of a low surface roughness. It has also been demonstrated that surface roughness heavily affects the results of the alumina coating process used extensively in the gas turbine industry. Surface roughness affects these two processes, and many more, due to the effects that roughness has on many physical characteristics of solids such as, but not limited to: wetting, adhesion, contact mechanics, and friction.
[0005] There exists a need for a profilometer capable of gathering roughness statistics in industrial and other field environments (i.e. non-laboratory environments). Various types of profilometer tools are available on the market. The most commonly employed type of profilometer is the stylus profilometer. The stylus profilometer measures the surface of a sample by running a mechanical tip along the surface. The vertical displacement of this tip is converted into an electric signal which corresponds to some specific height value. Despite the fact that this stylus profilometer is easy to use, it has several distinct disadvantages. The first disadvantage is the directional dependence of the device, as it only measures profile along a single direction. This can lead to an improper skew of the data when looking for results that are representative of the entire surface. Another disadvantage of the stylus profilometer is that, during measurements, the movement of the stylus along the sample surface can cause damage to the sample surface. Not only is sample damage generally unacceptable, especially for industrial processes, but the damage itself reflects poorly on the accuracy of the measurements. Due to the slow nature of taking stylus profilometer measurements, this technique would not work well for in-process measurements.
[0006] Optical techniques to measure topographical features of a sample surface offer many advantages over mechanical measures of a sample surface. An optical technique does not involve contact between the instrument and the sample surface, which reduces the chance of sample damage. Optical techniques also possess the ability to gather areal data. Therefore, using an optical technique, one can eliminate the directional dependence of the data gathered from a mechanical profilometry tool.
[0007] In various embodiments, the present disclosure considers a specifically developed focus metric, one which gives a qualitative assessment of roughness so that two images of the same subject can be compared to see which one was more in-focus. The focus metric is further a semi-quantitative measure of focus with some resilience to a given image subject. Aspects of the present disclosure also limit the computational time necessary to build the composite image in order to make the device suitable for in situ work.
[0008] In some embodiments, the device and methods in the present disclosure use a focus metric that applies a Laplacian filter, for example, and then quantifies the effect of the filter rather than quantifying the resulting filtered image itself. The effect of the filter may be quantified by taking the absolute difference between the original and unfiltered image at every point, and then dividing all of these differences by the value of the original image at each particular location. These fractional measures of change may then be converted into percentages to generate more comfortable values to work with, and then the percentages are averaged. The average percent change of each point in the filtered image is an example of the focus metric employed herein.
[0009] Due to the fact that this filtering process has a larger effect upon an in-focus image than an out-of-focus image, the focus metric increases with increasing focus in an area. The focus metric employed in embodiments disclosed herein can also use the unsharp masking method to filter the image, which sharpens in-focus images more than out-of-focus images. This focus metric obtains its resilience against an image subject due to the fact that it measures the change against the original image. Other focus metrics, by using the results of the shift rather than the shift itself, provide far less robust metrics.
[0010] In some embodiments of the present disclosure, the focus metric may be calculated over an image patch, as opposed to over a single pixel. While pixel-based focus can be established, such a process is often too computationally intensive given the goal of making the presently disclosed device and related methods suitable for in situ work.
Depth from Defocus
[0011] Depth from defocus (DfD) is a method that involves taking a series of optical images of a sample surface from varying heights, and then stitching together the in-focus regions of these images to generate a composite image and height map. This method creates an artificial, but high, depth-of-focus for the composite image, meaning that the composite image appears to be acceptably in-focus in all regions. By knowing which image in a given series is the most in-focus and at what vertical position that image was located, one can generate a height map to correspond with the composite image. Microscope manufacturers have employed certain similar techniques in some limited applications, but none as part of a portable device (e.g., handheld) configured for in situ work in a wide range of environments and operating orientation angles, as disclosed herein. As used herein, “handheld” can mean that which can be conveniently placed and moved with only one hand, and can be considered portable.
[0012] The profilometer device disclosed in some embodiments herein operates on the DfD principal, stitching together multiple, largely unfocused images into one, entirely focused image. Using these same images, it is capable of returning roughness statistics (e.g., R a , R z , S a , etc.) from a surface. In various embodiments, the device is completely portable, making it viable for in situ use.
SUMMARY
[0013] In some embodiments, a portable optical surface profilometer device is provided that includes a mechanism for capturing at least one image comprising an objective lens, wherein the objective lens has a focal plane that is movable along a z-axis substantially perpendicular to a surface to be measured. The device may also include a mechanism for incrementally moving the focal plane of the objective lens along the z-axis, a communications interface for receiving commands for movement of the focal plane of the objective lens and the at least one image captured by the image capturing mechanism, a power supply, and a housing with a handle. In some embodiments, the image capturing mechanism may include a charge coupled device. The profilometer device may also include a light for illuminating the surface to be measured. Such a light may, in some embodiments, include a ring light that is coupled to the objective lens.
[0014] The mechanism for incrementally moving the focal plane of the objective lens may take one of at least two forms. In some embodiments, the mechanism may include a motor, a motor controller, a driver, an actuator coupled to the motor and objective lens for moving the objective lens along the z-axis, and an encoder for determining incremental movements of the objective lens along the z-axis. Such embodiments may also include a spine, wherein the image capturing mechanism, the objective lens, the motor, the motor controller, the driver, and the encoder are coupled to the spine and are enclosed substantially within the housing. The focal plane may be movable over a range of at least 10 mm.
[0015] In certain other embodiments, the mechanism for incrementally moving the focal plane of the objective lens may include an adaptive lens for varying the position of the focal plane along the z-axis relative to a voltage applied to the adaptive lens. These embodiments may similarly include a spine, wherein the image capturing mechanism, the objective lens, and the adaptive lens are coupled to the spine and are enclosed substantially within the housing. The adaptive lens may have a curvature range for moving the focal plane of the objective lens over a range of at least 10 mm.
[0016] The communications interface of the device may be configured to communicate with a computer. The computer may provide commands for movement of the focal plane of the objective lens, and the at least one image captured by the image capturing mechanism may be processed by the computer to calculate one or more roughness statistics. The computer may be internal or external to the housing. The device may also include a user interface and/or display for receiving commands from a user and/or presenting information to a user.
[0017] Other features of the device may include the ability of the image capturing mechanism and mechanism for incrementally moving the focal plane of the objective lens to operate at any orientation angle. The housing may also include features allowing for use of the device in a wide range of temperature, humidity, and other environmentally diverse conditions. Accordingly, the presently disclosed profilometer is readily field deployable for use outside the confines of a laboratory.
[0018] In certain other embodiments, the present disclosure is directed to a method of optically measuring topographical features of a sample surface for computing one or more roughness statistics of the sample surface. The method may include the steps of providing a portable optical surface profilometer device that includes a mechanism for capturing at least one image having an objective lens wherein the objective lens has a focal plane that is movable along a z-axis substantially perpendicular to a surface to be measured, a mechanism for incrementally moving the focal plane of the objective lens along the z-axis, and a communications interface for receiving commands for movement of the focal plane of the objective lens, and the at least one image captured by the image capturing mechanism. Next, a series of images of a region of the sample surface may be captured at incremental distances along the z-axis, and a height may be recorded at which each image is taken. The images may then be divided into a grid of substantially equally sized patches, wherein each patch is associated with a grid location in an XY-plane, the XY-plane being substantially parallel to the sample surface. The patches associated with each grid location in the XY-plane may then be stacked according to height. A focus metric may then be calculated for each patch to determine which patch in each stack is most in focus. A height map may then be generated of the imaged region based on the height associated with the most in focus patch in each stack. The height map may then be used to calculate a roughness statistic for the sample. The roughness statistic may include one or more of R a , S a , R RMS , Rz, and R q .
[0019] The focus metric may be one or more of a Laplacian filter or unsharp masking method that is applied to each patch to quantify the effect of the filter and/or masking method on each patch to determine relative focus.
[0020] In some embodiments, where the mechanism for incrementally moving the focal plane of the objective lens includes an adaptive lens for varying the position of the focal plane along the z-axis relative to a voltage applied to the adaptive lens, an additional step of performing a digital zoom on the series of images to compensate for magnification effects of the adaptive lens, and subsequently cropping out any parts of the images that do not have a correlating section in all other images in the stack, may be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIGS. 1-2 are exemplary sample images of a sample surface divided into four quadrants or patches, with different degrees of focus in each sample image.
[0022] FIG. 3 is a composite image of the image in FIG. 1 and the image in FIG. 2 .
[0023] FIG. 4 is an illustrative wavelength image showing quantum efficiency of a compact and lightweight industrial camera.
[0024] FIG. 5 is an illustrative schematic of some embodiments of the presently disclosed profilometer.
[0025] FIG. 6 shows an exemplary power supply circuit for use in connection with some embodiments of the presently disclosed profilometer.
[0026] FIG. 7A is a cutaway view and FIG. 7B is an encased view, respectively, of an exemplary embodiment of the presently disclosed profilometer.
[0027] FIG. 8 is a schematic diagram of the interaction of the various components of certain embodiments of the presently disclosed profilometer, including a power supply.
[0028] FIG. 9 is an illustrative diagram of an embodiment of the presently disclosed profilometer employing liquid lens technology.
DETAILED DESCRIPTION
[0029] As shown in the exemplary embodiment of FIGS. 5 and 7 A- 7 B, a profilometer 10 is provided having a handle portion 12 and a body portion 14 . The body portion 14 may comprise a spine 20 , to which various hardware elements are secured, including a controller 22 , a driver 24 , an encoder 26 , a motor 28 , an actuator 30 , an image capturing mechanism or camera 32 , and an objective lens 34 .
[0030] Referring now to FIG. 5 and FIGS. 7A and 7B , in some embodiments, the spine 20 includes a top portion 81 and a bottom portion 82 , and the controller 22 may be mounted to a first side 83 of the spine 20 , and the actuator 30 , imaging mechanism (e.g., camera 32 ), and objective lens 34 may be mounted to a second side 84 of the spine 20 . At or near the top portion 81 of the spine 20 , the driver 24 , motor 28 , and encoder 26 may be mounted. As shown in FIG. 5 , for example, the motor 28 and encoder 26 are mounted so as to extend beyond the height and/or the top portion 81 of the spine 20 . A light 35 may be provided at or about an end of the objective lens 34 for illuminating the surface to be measured. A housing 14 having a handle 12 may also be included around the various components (e.g., spine 20 , actuator 30 , imaging mechanism 32 , lens 34 , driver 24 , motor 28 and encode 26 ) of embodiments of the profilometer device 10 for providing environmental protection to the components housed therein. The handle 12 may also provide efficient means for a user to manipulate and/or transport the device when in use In various embodiments, the arrangement of the internal components of the device 10 and encapsulation of those components by the housing 14 facilitates the portability, environmental ruggedness and operability of the device.
[0031] In operation, the controller 22 and driver 24 may provide operational voltages to the motor 28 . The motor 28 in turn acts on the actuator which moves the imaging mechanism (e.g., camera 32 ) and objective lens 34 along the z-axis. The encoder 26 is also coupled to the actuator such that it can determine with great precision the displacement of the objective lens 34 along the z-axis.
[0032] The proper selection and integration of linear actuators, complimentary metal-oxide-semiconductor (CMOS) cameras, and microscope objective lenses of appropriate size, weight, ability and interoperability are critical for the desired precise operation of the device as a whole. For a suitable camera or other image capturing device, one with small pixel dimensions, USB 3.0 data transfer and small size can be employed. In one embodiment, the EO USB 3.0 monochrome camera available from Edmund Optics of Barrington, New Jersey can be employed. The Edmund Optics CMOS camera has dimensions of 29 mm 3 and its mass, 43 g, is quite low. Such camera also has pixel dimensions of 2.2 μm 2 and a sensor which is manufactured by Aptina Imaging Corporation of San Jose, Calif. Small pixel size permits use of a lower-powered magnification objective lens while still gathering a desired level of spatial resolution. Also, even with 2560×1920 pixels, the sensor area is only 5.6×4.2 mm, meaning that the camera as a whole can be kept to a small size. In various embodiments, the camera employed can be controlled by suitable software to capture up to 15 frames per second, meaning that the camera will not be the limiting factor in the speed with which images can be gathered and processed. As the camera can be provided with USB 3.0 (SuperSpeed) connectivity, various integratable features can be employed. For example, this connectivity can assist with powering and controlling the camera, actuator and light setups from one cable to a computer (e.g., laptop). Images can be transferred to the host device (e.g., laptop) for processing via the USB 3.0 or other available interface.
[0033] With regard to the linear actuator 30 , it is desirable to be able to move the camera 32 in precise increments corresponding to differing focal planes. An electric linear actuator 30 provides a small size and precise, controllable, incremental movement. In some embodiments, a linear actuator 30 in the form of BG15 stage from Specialty Motions, Inc. of Corona, Calif. can be employed, as providing suitable balance between step size, unit size and the required peripherals (e.g., drivers, controllers, etc.). The BG15 stage can be used with, for example, a Nema 17 motor mount, Oriental Motor CRK-544 stepper motor with an encoder and an SCX10 controller. Of course, other comparable components may be employed instead. Exemplary functions of each component within the linear actuator system are outlined below.
[0034] The BG15 stage, for example, provides high precision construction (±1 μm positioning repeatability) and suitable travel, e.g., 75 mm. For most surfaces, a 50 μm measurement range would be sufficient, but the greater travel is useful when finding the first plane of focus. The Nema 17 motor mount is necessary in some embodiments to house the drive motor, as outlined below.
[0035] The Oriental Motor CRK-544, for example, provides a suitable degree of precision. Its 0.36° step angle provides for stage steps of just under 3 μm, allowed in part by a very finely threaded rod along which the stage travels. The encoder 26 which can be provided with the chosen motor 28 allows for up to 1000 data points per revolution. This means that the device of the present disclosure can, in some embodiments, indicate exactly where in its rotation the motor is at every instant, and by association, exactly where in its range the stage is located. Knowing exactly where the stage is at all times is critical, as the computer program can compensate for differences in step size, but not for inaccurate relative position.
[0036] The SCX controller (an exemplary controller 22 ) also preferably has small dimensions to allow it to be integrated into the handheld system disclosed herein rather than into a larger external box. In various embodiments, the SCX controller offers a variety of data transfer connectors (e.g., USB 2.0, RS-232 and CANopen). In some embodiments, USB 2.0 can be employed, as it offers the ability for easy interconnectivity with a laptop control unit, for example. The controller 22 can also be provided with its own software package which can be integrated into software adapted for operating the profilometer.
[0037] In some embodiments, the housing ( 12 , 14 ) for the portable optical profilometer can be designed for both protection of the internal components and for user-friendliness in the field. While aluminum can be employed as the housing material, molded plastic and other materials can also be employed. In various embodiments, an aluminum U-channel extrusion can be employed as a base platform because of its easy machinability and high strength-to-weight ratio. For example, two pieces of such an extrusion can be oriented in a clamshell configuration, with necessary accommodations for fastening the components to the two parts which compose the shell. The overall dimensions may be dictated by the size of the internal components, and by the travel limitations of the linear actuator/camera/lens assembly, for example.
[0038] In operation, the hardware may acquire a series of optical images of the sample surface. This series of images is of the same general region on the sample surface, but is taken at varying heights which are recorded alongside the image, By taking the images at varying heights, different regions of the sample appear in focus for each picture. After acquiring the images, each image is broken down into a series of 100×100 pixel squares and stacked with the other 100×100 sections of the same region. Each square in a given stack is then given a focus metric based variation of the image when a sharpening filter is applied. If an image is in better focus, the sharpening filter can change it by a greater degree. Thus, a higher focus metric represents a more in-focus image. One can use this knowledge to then select the most in-focus square of each region. Because optical imaging theory dictates that depth-of-field is a limited region which corresponds to a particular range of distances between the image capture device and the imaged object, the most in-focus square of a region gives height information about that region. By using this technique, a height map of the specimen can be generated from which one can compute a variety of roughness statistics. Appropriate software instructions may be provided in one or more memories operable by one or more processors for carrying out the stated functions.
[0039] In various aspects, the DfD algorithm employed in accordance with embodiments of the present disclosure begins by taking a series of images of the same region in space and records the height value at which each image was taken. In regards to surface metrology, this region in space will be a sample surface. Consistent with the above description, all of the images are broken down into a series of separate, rectangular patches which are then stacked with the corresponding patches from the other images. A simple exemplary version of this process is illustrated in FIGS. 1-3 . In FIG. 1 , a first image 100 in the stack of the sample surface is shown divided into four patches. In FIG. 2 , a second image 200 in the stack of the sample surface is shown, divided into four patches that correspond to the patches in the first image 100 shown in FIG. 1 .
[0040] Once all of the patches have been stacked, the algorithm goes through each patch separately and finds the patch that is most in-focus of that stack, as described above. The most in-focus patch is the patch that yields the highest focus metric. Once the most in-focus patch has been selected, the software algorithm assigns that patch to the final, composite image and takes the height value associated with the image that the most in-focus patch came from and assigns that height value to a height map. The height value's position on this map and the patch's place in the final, composite image is determined by the patch's position in the XY plane in its original image. This process of finding the most in-focus patch and assigning it to the final, composite image and its height value to the final height map is repeated for every separate stack. As used herein, the “XY plane” refers to the horizontal plane which runs parallel to a perfectly flat sample surface. The “Z axis” refers to the vertical axis which runs perpendicular to a perfectly flat sample surface. Working distance is the distance along the Z axis between the focal plane and the final aperture of a given microscopy arrangement. This final aperture coincides with the end of the objective lens 34 .
[0041] After the algorithm processes each individual stack, the final, composite image shows an entirely in-focus image of the sample surface. FIG. 3 shows an exemplary composite image 300 based on the exemplary images 100 , 200 shown in FIG. 1 and FIG. 2 . The height map should have a height value for each region of the sample surface, with the size of each region determined by the size of the patches employed. As shown in FIG. 3 , the best patches from the other images are compiled here for a fully in-focus image. The top-right and top-left patches came from the first image 100 ( FIG. 1 ) and the bottom-right and bottom-left patches came from the second image 200 ( FIG. 2 ).
[0042] It will be appreciated that the DfD process assists in operation due, in part, to the amount of data that can be extracted from knowledge of the depth of field. Depth of field describes how far from the absolute focal plane of an optical imaging device one can move along the Z axis and still have the image appear acceptably in focus. If movements along the Z axis exceed the depth of field for a given microscopy arrangement, then the images taken at these different Z axis positions will yield different focus metrics. In various embodiments, the working distance of the arrangement remains constant throughout all Z axis positions of the camera and optics, so the only Z axis factor that changes the focus quality is the Z axis position of the camera. This relationship enables one to know the relative heights.
[0043] In various embodiments, the DfD algorithm can employ rectangular patches that are 100×100 pixels. This patch size allows for 192 separate patches to be examined over the full images gathered from the device, which are 1600×1200 pixels.
[0044] In various embodiments, the patch size can be selected as 100×100 pixels for a given initial image size of 1600×1200 pixels. Other patch sizes and shapes, such as 10×10 pixels, 20×20 pixels, and 200×200 pixels, for example, can be employed. To the extent threading of the camera is incompatible, an appropriate adapter can be employed. For example, the RMS-1″-32 adapter from ThorLabs Inc. of Newton, New Jersey can be used.
[0045] The objective lens 34 in the portable optical profilometer 10 of the present disclosure offers a shallow enough depth of focus that the software program can detect changes in focus levels while still offering a large enough field of view that a meaningful area of the surface under investigation can be inspected. Additionally, an objective lens with infinity correction can be employed, such that no additional lensing is necessary to project the desired image onto the camera sensor. Further, size and weight can be considered with regard to the objective lens, as the vertical orientation of the linear actuator meant that the force of gravity would be working against the motor. In some embodiments, the LMPLFLN50xBD from Olympus Corporation of Center Valley, PA can be employed. Its features can be found in Table 1 below.
[0000]
TABLE 1
Optical characteristics of the Olympus LMPLFLN50xBD
Olympus LMPLFLN50xBD
Numerical Aperture
0.50
Working Distance (mm)
10.6
Focal Distance (mm)
3.6
Depth of Focus (μm)
2.5
Weight (g)
85
[0046] As the linear actuator can offer a large travel range, it will be appreciated that the profilometer of the present disclosure is not limited to the use of only the above lens. Should another lens be used, differences in physical length and working distance can be adjusted for by use of the linear actuator and associated software.
[0047] In order to provide uniform illumination on the surface under investigation, a lighting setup for the imaging system can be employed. For example, a ring light arrangement 35 ( FIG. 7 ) can take maximum advantage of the long working distance of the objective lens, depending upon the lens employed. In various embodiments, the angle of incidence of six LEDs in the system can be, for example, 17.5° above horizontal. The wavelength of the LED (e.g., 470 nm) can be chosen based upon the characteristics of the imaging mechanism employed. A representative wavelength is shown in chart 40 shown in FIG. 4 . In various embodiments, the LEDs of the ring light 35 can be wired in parallel, and connected directly to the power supply circuit. This allows the ring light 35 to not only illuminate the sample, but also to act as a visual indicator as to whether the device has been properly powered.
[0048] In some embodiments, the spine can be created using 3D printing technology and may include an acrylonitrile butadiene styrene (ABS) plastic material. This material is lightweight and durable. Also, a tripod foot system 44 can be employed to assist in setting the device down in appropriate position when not in use, for example. Further, a single power supply circuit can be employed to provide suitable power to the components of the device. Table 2 illustrates exemplary power requirements, and FIG. 6 illustrates a suitable exemplary power supply circuit 600 diagram. Additionally, FIG. 8 shows an exemplary schematic diagram 800 illustrating the connectivity arrangement of the power supply with various components of the device in various embodiments of the present disclosure. Once designed in software (such as with a CAD program, for example), the circuit can be transferred to a printed circuit board (PCB) by means of an etching process, and the necessary components may be soldered into place.
[0000]
TABLE 2
Power requirements for various exemplary electrical components
Component
Electrical Requirements
Controller
24 V -- 260 mA
Driver
24 V -- 700 mA
Ring light
5 V -- 120 mA
Camera
Power over USB 2.0 (5 V - 500 mA
max)
[0049] One of several advantages of various embodiments of the profilometer in the present disclosure is its portability and ruggedness. For example, the presently disclosed profilometer is distinguishable from some existing systems, in part, because it is operable at any orientation angle, thereby providing for the measurement of roughness statistics in the field in surfaces oriented in any direction. The ability to take measurements at any orientation angle provides a distinct advantage over the prior art. Additionally, the presently disclosed profilometer includes a housing and an arrangement of component parts that allows for operation in a wide range of varying environmental conditions (e.g. wide ranges of temperature, humidity, weather related elements, etc.). Both of these characteristics make the presently disclosed profilometer readily field deployable, having the advantage of operating outside the limitations imposed by a laboratory, for example.
[0050] It will be appreciated by those skilled in the art that the hardware platform of the presently disclosed device can be provided in alternative arrangements to that disclosed above. For example, instead of employing a stepper motor and physically moving the camera in order to change the location of the focal plane along the Z axis, one could feasibly use liquid lens technology to move the focal plane along the Z axis. Liquid lens technology enables an adaptive lens, whose curvature can be changed by applying varying levels of voltage to the lens itself. An exemplary embodiment of such a profilometer device 900 employing liquid lens technology is shown in FIG. 9 . The changes in curvature move the focal plane along the Z axis, though at the cost of modifying magnification along the way. However, changes in magnification can be corrected with additional computer algorithms, maintaining the feasibility of this proposal.
[0051] In addition, the optical profilometer of the present disclosure can be used to gather cleanliness data as well as height data. Surface cleanliness, usually judged by the presence or absence of contaminant, is a parameter of interest to many manufacturing companies. Additional computer algorithms could be constructed to analyze the stack of images and composite image in order to detect potential contaminant(s).
[0052] In employing liquid lens technology, the presently disclosed device may still employ the same focus metric described above, with DfD, but instead can use a liquid lens to mimic the effect of the stepper motor. This version of the device is also highly portable, if not more portable, than the device described above. Its design also incorporates less moving parts, which makes it even more resilient to the conditions present in in situ work and various operating angles of orientation.
[0053] Several hardware modifications can be employed with the liquid lens technology. Because of the lower power requirements in the liquid lens-enabled device, the device is able to be completely powered and controlled via a USB 3.0 interface, for example. In employing the liquid lens, the previously used motor-driven linear actuator is replaced a variable-focus liquid lens, which can be obtained commercially, for example, from Optotune AG of Switzerland. In this lens, a flexible membrane is filled with a fluid with an n-value greater than unity. A piezoelectric ring around the circumference of the membrane deflects as a voltage is applied, forcing the curvature of the membrane to change; this, in turn, changes the focal length of the lens. By placing the liquid lens in series with a 20×, infinity-corrected objective lens, for example, the system is able to focus through a height of approximately 80 μm. Changes in image magnification can be corrected through software, for example.
[0054] The imaging mechanism (e.g., camera 32 ) can be the same as that employed in previously described embodiments above. A darkfield illumination setup, similar to that described above, can also be employed in the liquid lens-based device, using an LED-based ring light 35 , for example. Such a ring light 35 can be fabricated using a 3D printer, for example.
[0055] In order to integrate the liquid lens successfully, several modifications to the software are required. While the same image processing algorithms can be used to sort through the images, the liquid lens subtly changes magnification when moving through the various focal lengths. The software corrects for this by performing a digital zoom. After the zoom, the software crops out any parts of an image that do not have a correlating section in all of the other images of the stack. Further, control of the liquid lens is managed through the software itself. Much like with the stepper motor, the liquid lens can be controlled directly through a serial port interface due to the USB 3.0 interface.
[0056] In addition to hardware modifications to accommodate any heating issues of the assembly, the software can also account for temperature problems. The lens has commands which can make certain necessary adjustments to address certain heating concerns.
[0057] To further increase portability of the entire platform, and not just of the optical microscopy component, it will be appreciated that a smaller form-factor computer may also be employed. Due to the simple focus algorithms and liquid lens commands, the exemplary laptop based computing system discussed above could feasibly be replaced with a smaller computing system such as, for example, the Raspberry Pi or the Beagle Bone Black. These computing systems are only the size of a credit card, but still have the computing power necessary to run the required programs. In such embodiments, a user interface and/or display for communicating roughness statistics and other related information to the user may be provided. The user interface and/or display may be used in place of functions provided by, for example, an external laptop. Those having skill in the art will appreciate that the user interface and/or display may be of any convenient form or design, including for example, touch screen user interfaces, buttons, switches, LCD displays, digital numerical displays, and the like, and may be secured to the housing 14 or provided externally from the device 10 .
[0058] Once data is collected as described, surface roughness analysis can proceed. There are a wide variety of roughness statistics available that can be calculated from a single profile. The average roughness, R a , is the most common and a robust general measurement of the characteristic surface roughness and is used widely in industry. Other roughness statistics include the root mean squared roughness, R q , which is more sensitive to outlying features and is often utilized when deep peaks or valleys are of greater concern, and the ten point height, R z , which captures the average distance between the highest and lowest features of the profile. It is important to note than when using a single numerical representation of surface roughness a great deal of information can be lost, as many surfaces with widely disparate topologies can often share the same roughness value. These variations range from the shape, height, and density of features, to directional textures. Most applications envisioned for a portable, non-contact profilometer, such as control of wide area processes such as grit blasting, can be expected to impart an isotropic texture with a controlled morphology. Depending on the roughness statistics or scales desired, modifications to the lens magnification and depth from defocus algorithm (notably smaller patch sizes) may be required.
[0059] One complication associated with the use of the average roughness statistic, R a , is that it relies on deviations from an expected mean value. The simplest evaluation of the mean for a 1D profile is to apply a line of best fit. This, however, introduces an undesirable sampling interval dependence on the R a statistic, which is ideally invariant to the sample length. The solution to this interval size problem is the application of a weighted average instead of a line of best fit. While the exact weighting function can be altered to suit a particular situation, there is a comprehensive NIST standard protocol available that is utilized in commercially available mechanical profilometers. This protocol introduces a cutoff parameter, λ c , and is the equivalent to the application of a low band pass filter to the 1D profile; allowing for the profile to be separated into a “waviness” macro-roughness profile, and a “roughness” micro-roughness profile. Following standardized protocol (ISO 4288:1996) a non-periodic profile with a R a between 2 and 10 μm requires a cutoff value of 2.5 mm.
[0060] The equivalent to the 1 D profile R a measurement in a 2D height profile is referred to as S a . The switch in nomenclature is often ignored as these two statistics are estimators of the same surface property. S a is invariant to orientation and will always capture the highest features in a region, which 1D R a measurements may miss, so it does behave differently than R a as a statistical quantity and deserves a separate designation. S a values are often measured by fitting a plane of best fit, or a polynomial surface of best fit, to a profile due to computational simplicity. A Gaussian weighted average can be applied in two dimensions to match the 1D NIST standard methodology but computation times increase proportional to the number of height values squared, or the patch size pixel length to the fourth power. Consequentially, rigorously computing S a using weighted averages on a 1600×1200 pixel profile can take a single processer several months.
[0061] In carrying out the above described inventive aspects, it will be appreciated that embodiments of the presently disclosed system may include a computer-based system, where the components can be implemented in hardware, software, firmware, or combinations thereof. Users may access the system using client computing devices, such as terminals, desktop computers, laptop computers and mobile communications devices (MCDs), for example, as described above. It will be appreciated that the presently disclosed system can incorporate necessary processing power and memory for storing data and programming that can be employed by the processor(s) to carry out the functions and communications necessary to facilitate the processes and functionalities described herein. Each client computing device may also be configured to communicate with one or more application servers. Appropriate encryption and other security methodologies can also be employed by the system, as will be understood to one of ordinary skill in the art.
[0062] Unless otherwise stated, devices or components of the present disclosure that are in communication with each other do not need to be in continuous communication with each other. Further, devices or components in communication with other devices or components can communicate directly or indirectly through one or more intermediate devices, components or other intermediaries. Further, descriptions of embodiments of the present disclosure wherein several devices and/or components are described as being in communication with one another do not imply that all such components are required, or that each of the disclosed components must communicate with every other component. In addition, while algorithms, process steps and/or method steps may be described in a sequential order, such approaches can be configured to work in different orders. In other words, any ordering of steps described herein does not, standing alone, dictate that the steps be performed in that order. The steps associated with methods and/or processes as described herein can be performed in any order practical. Additionally, some steps can be performed simultaneously or substantially simultaneously despite being described or implied as occurring non-simultaneously.
[0063] It will be appreciated that algorithms, method steps and process steps described herein can be implemented by appropriately programmed general purpose computers and computing devices, for example. In this regard, a processor (e.g., a microprocessor or controller device) receives instructions from a memory or like storage device that contains and/or stores the instructions, and the processor executes those instructions, thereby performing a process defined by those instructions. Further, programs that implement such methods and algorithms can be stored and transmitted using a variety of known media.
[0064] Common forms of computer-readable media that may be used in the performance of the present disclosure include, but are not limited to, floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic medium, CD-ROMs, DVDs, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, RAM, PROM, EPROM, FLASH-EEPROM, any other memory chip or cartridge, or any other medium from which a computer can read. The term “computer-readable medium” when used in the present disclosure can refer to any medium that participates in providing data (e.g., instructions) that may be read by a computer, a processor or a like device. Such a medium can exist in many forms, including, for example, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks and other persistent memory. Volatile media can include dynamic random access memory (DRAM), which typically constitutes the main memory. Transmission media may include coaxial cables, copper wire and fiber optics, including the wires or other pathways that comprise a system bus coupled to the processor. Transmission media may include or convey acoustic waves, light waves and electromagnetic emissions, such as those generated during radio frequency (RF) and infrared (IR) data communications.
[0065] Various forms of computer readable media may be involved in carrying sequences of instructions to a processor. For example, sequences of instruction can be delivered from RAM to a processor, carried over a wireless transmission medium, and/or formatted according to numerous formats, standards or protocols, such as Transmission Control Protocol/Internet Protocol (TCP/IP), Wi-Fi, Bluetooth, GSM, CDMA, EDGE and EVDO.
[0066] Where databases are described in the present disclosure, it will be appreciated that alternative database structures to those described, as well as other memory structures besides databases may be readily employed. The drawing figure representations and accompanying descriptions of any exemplary databases presented herein are illustrative and not restrictive arrangements for stored representations of data. Further, any exemplary entries of tables and parameter data represent example information only, and, despite any depiction of the databases as tables, other formats (including relational databases, object-based models and/or distributed databases) can be used to store, process and otherwise manipulate the data types described herein. Electronic storage can be local or remote storage, as will be understood to those skilled in the art.
[0067] It will be apparent to one skilled in the art that any computer system that includes suitable programming means for operating in accordance with the disclosed methods also falls well within the scope of the present disclosure. Suitable programming means include any means for directing a computer system to execute the steps of the system and method of the disclosure, including for example, systems comprised of processing units and arithmetic-logic circuits coupled to computer memory, which systems have the capability of storing in computer memory, which computer memory includes electronic circuits configured to store data and program instructions, with programmed steps of the method for execution by a processing unit. Aspects of the present disclosure may be embodied in a computer program product, such as a diskette or other recording medium, for use with any suitable data processing system. The present disclosure can further run on a variety of platforms, including Microsoft Windows™, Linux™ Sun Solaris™, HP/UX™, IBM AIX™ and Java compliant platforms, for example. Appropriate hardware, software and programming for carrying out computer instructions between the different elements and components of the present disclosure are provided.
[0068] The present disclosure describes numerous embodiments, and these embodiments are presented for illustrative purposes only. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosed device and methods, and it will be appreciated that other embodiments may be employed and that structural, logical, software, electrical and other changes may be made without departing from the scope or spirit of the present disclosure. Accordingly, those skilled in the art will recognize that the present disclosure may be practiced with various modifications and alterations. Although particular features of the present disclosure can be described with reference to one or more particular embodiments or figures that form a part of the present disclosure, and in which are shown, by way of illustration, specific embodiments of the disclosure, it will be appreciated that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described. The present disclosure is thus neither a literal description of all embodiments of the disclosure nor a listing of features of the disclosure that must be present in all embodiments. | A hand-portable optical surface profilometer device can employ depth from defocus techniques to measure surface roughness in wide-area industrial processes. | 6 |
The subject matter herein claims benefit of prior filed U.S. patent application Ser. No. 60/307,760, filed on Jul. 25, 2001 and entitled “Spring Assembly”; the disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The instant invention relates to a spring assembly for use in a parking brake system in order to maintain a minimum load or tension in a parking brake cable.
BACKGROUND OF THE INVENTION
Spring accumulators can be employed in parking brake systems. An example of a conventional spring accumulator is disclosed in U.S. Pat. No. 5,232,207 (issued Aug. 3, 1993); hereby incorporated by reference.
Parking brake systems can be employed at any suitable location on a vehicle. Examples of such locations comprise drive lines or shafts, wheel brakes, drum brakes, servo actuated brakes, among other types and locations. Parking brake systems typically include a parking brake cable that is either electrically or manually actuated by applying a tensile force to a cable strand (which also applies a compressive force to the surrounding cable conduit). This force is in turn applied to the parking brake system that causes a frictional material (e.g., brake pad) to engage thereby maintaining the vehicle in a predetermined position. The angle and orientation (i.e., up or down hill) at which a vehicle is parked as well as the overall weight of the vehicle (including any payload) can affect operation of the parking brake system. There is a need in this art for a parking brake system having a preloaded force or minimum tension in the parking brake cable in order to minimize such affects on the parking brake system.
SUMMARY OF THE INVENTION
The instant invention relates to a spring assembly for use in a parking brake system that solves minimum force problems associated with conventional parking brake systems. The inventive assembly imparts a minimum force (e.g., tensile force) onto the parking brake cable of the parking brake system when the parking brake is applied. This minimum force improves the effectiveness of the parking brake system (e.g., when the vehicle is parked at an angle or carrying relatively large loads). This minimum force can be used for 1 ) reducing, if any eliminating, any vehicle roll-forward or backward, 2 ) increasing the force applied to the parking brake cable, 3 ) maintaining a force within a parking brake cable, 4 ) maintaining the minimum force required in the brake without requiring excessive force, among other benefits.
The inventive spring assembly can be employed upon a wide range of vehicles. Examples of such vehicles comprises DOT Class 5-7. In the case of DOT Class 5-7 vehicles, the inventive spring assembly is normally employed in conjunction with a drive line parking brake system.
The inventive spring assembly comprises a sliding collar, a wire ring located about the exterior diameter of the sliding collar, a locking collar, a spring and a sleeve for receiving the aforementioned components. The size of these components depends upon the size and function of the vehicle, and type and size of a parking brake cable (or strand) and parking brake system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-D show the inventive spring assembly in an assembled configuration.
FIGS. 2A-B show the sleeve component of the assembly illustrated in FIGS. 1A-1D .
FIGS. 3A-3C show the locking collar component of the assembly illustrated in FIGS. 1A-1D .
FIGS. 4A-4C show the sliding collar component of the assembly illustrated in FIGS. 1A-1D .
FIG. 5 shows the spring assembly illustrated in FIGS. 1A-1D in an installed configuration including a cable.
All dimensions show on the drawings are for purposes of illustration only, and such components can vary in size and exact configuration depending upon the parking brake system in which they are employed.
DETAILED DESCRIPTION
The instant invention relates to a spring assembly that applies a minimum tensile load or force upon a cable or strand. The spring assembly comprises a sleeve that is dimensioned for receiving a first (e.g., sliding) and a second (e.g., locking) collar. A spring is maintained between the collars. A cable or strand extends into and through the sleeve. A wire ring around the sliding collar prevents the sliding collar from disengaging a bracket that determines the location of the spring assembly (e.g., the sliding collar is inserted through an opening in the bracket such that the bracket is maintained between the wire and sliding collar). When an end portion of the cable or strand that extends through the spring assembly is affixed to an apparatus for operating the cable (e.g., foot pedal or over center lever), the spring applies a force against the locking collar and in direction opposite from the cable operating apparatus thereby increasing the tensile load in the cable or strand.
Certain aspects of the inventive assembly are illustrated by reference to the Drawings. Referring now to the Drawings, FIGS. 1A-1D illustrate the inventive spring assembly in an assembled configuration. FIGS. 1A-1D illustrate the sliding collar (with its wire ring), spring and locking collar all located about the exterior surface and along the longitudinal axis of the sleeve. The spring is at least partially compressed between the sliding collar and the locking collar. The maximum travel position of the sliding collar and spring along the length of the sleeve are defined by edges on the sleeve. The travel position of the sliding collar relative to the locking collar also defines the degree to which the spring is compressed, and in turn the force that is available for application to the parking brake cable of the parking brake system.
FIGS. 1A through 1D illustrate one aspect of the inventive spring assembly in an assembled configuration. A sleeve 1 defining an opening or bore 2 extending along the longitudinal axis of sleeve 1 . Sliding collar 3 and locking collar 4 are received about sleeve 1 . A spring 5 is maintained between collars 3 and 4 in a compressed state. A wire 6 affixes sliding collar 3 to a mounting bracket (not shown).
The spring (and associated or related components) can be of any suitable size and application force. The application force can range from about 100 to at least about 1,000 pounds (e.g., 150 to 500 pounds). The specific size will vary depending upon the vehicle and mounting brackets associated with the spring assembly.
FIGS. 2A-B show the sleeve component of the assembly illustrated in FIGS. 1A-1D . The sleeve defines edges for determining the maximum travel distance of the sliding collar and provide mating surfaces for engaging the collars. The enlarged exterior diameter and edge illustrated on the left hand side of FIGS. 2A-B are associated with the sliding collar. The sliding collar (and its wire ring) are installed by being slid from the right hand side of the sleeve along the length of sleeve until engaging the enlarged exterior diameter. The spring is then installed in a similar manner. If desired, the sliding collar can be connected to the sleeve by employing an e-clip, among other retainers.
FIGS. 2A and 2B illustrate the sleeve 1 shown in FIGS. 1A through 1D . Sleeve 1 defines a circular edge or shoulder area 10 about the circumference of sleeve 1 . Edge 10 is dimensioned to provide a mating surface to engage sliding collar 3 thereby preventing sliding collar 3 from passing over area 10 . Sleeve 1 also defines a circular recessed slot or groove 11 about the exterior of sleeve 1 . Groove 11 defines an edge 12 that provides a mating surface for engaging locking collar 4 . The exterior diameter of sleeve 1 is greater than the smaller of the two openings defined on locking collar 4 thereby prevent locking collar 4 from traveling past edge 12 . Sleeve 1 defines area 13 that is dimensioned to mate with and receive a conduit end fitting of a cable or strand assembly (not shown). The portion of area 13 having the greatest diameter contacts the conduit end fitting and the portion of area 13 having the smallest diameter can be engaging for seating a seal. The conduit end fitting surrounds an end portion of the cable or strand. The conduit end fitting cannot travel beyond area 13 whereas the cable or strand extends along bore 2 and exits sleeve 1 .
FIGS. 3A-3C show the locking collar component of the assembly illustrated in FIGS. 1A-1D . The locking collar defines an annular exterior surface for receiving the spring. The locking collar defines overlapping openings for receiving the sleeve. The first and larger opening permits the locking collar to slide over the exterior dimension of the sleeve shown on the right hand side of FIGS. 2A-2B . As the locking collar travels along the longitudinal axis of the sleeve, the spring is compressed between the locking collar and the previously installed sliding collar. When the locking collar has compressed the spring to the extent desired, the locking collar is moved perpendicularly such that the second and smaller opening defined in the locking collar engages the sleeve. This engagement positions the locking collar about the sleeve and maintains the spring in an at least partially compressed state. The spring can be compressed further by applying the parking brake cable of the parking brake system. The sleeve is dimensioned to receive a locking collar. The locking collar has two openings. One is large enough to permit the locking collar to receive the exterior diameter of the sleeve shown on the right hand side of FIGS. 2A-B . The second opening defined in the locking collar receives the reduced exterior diameter of the sleeve adjacent to the exterior diameter of the sleeve shown on the right hand side of FIGS. 2A-B . The exterior dimensions of the sleeve compliment the interior dimensions of the openings defined in the locking collar (shown in FIGS. 1A-1D and described in greater detail in connection with FIGS. 3A-3C infra). The interior dimension of the right hand side of the sleeve is configured so as to receive a conduit end fitting of a parking brake cable. The strand of the parking brake cable extends from the conduit end fitting and passes through the sleeve within an interior channel or a groove defined within the sleeve (described in greater detail in connection with FIG. 5 infra). In an alternative aspect of the invention, the sleeve and locking collar comprise an integral component. Further, if desired, the locking collar can be connected to the sleeve by employing an e-clip, among other retainers.
FIGS. 3A through 3C illustrate locking collar 4 having first and second openings 20 and 21 . The diameter of opening 20 is larger than and not concentric with opening 21 . Opening 21 engages groove 11 and edge 12 of sleeve 1 . Locking collar 4 defines includes an annular or a circular surface 22 for engaging spring 5 .
FIGS. 4A-4C show the sliding collar component of the assembly illustrated in FIGS. 1A-1D . The interior surface of the sliding collar defines an opening for receiving the sleeve and permitting the sliding collar to move along the length of the sleeve. The sliding collar component includes an annular ring about the exterior diameter of the collar. The right hand side of the annular ring contacts the spring in a manner sufficient to compress the spring between the sliding collar and the previously described locking collar. The left hand side of the annular ring contacts a mounting bracket or plate for the inventive spring assembly. The exterior surface of the sliding collar also defines two grooves or channels for receiving a wire ring (the wire ring is typically a discontinuous loop), snap ring, e-clip, among other retainers. The wire ring can be moved between the two grooves. The placement of the wire ring within the two channels depends upon whether the inventive spring assembly has been installed in or against its mounting bracket. The mounting bracket or plate is positioned between the wire ring and the previously described left hand side of the annular ring. When the spring assembly is connected to the mounting bracket or plate, the wire ring is displaced from the groove having the larger diameter to the groove having the smaller diameter. As a result, the spring assembly wire ring functions to attach the spring assembly to the mounting bracket.
FIGS. 4A through 4C illustrate sliding collar 3 having an opening 30 for receiving sleeve 1 . Sliding collar 3 defines mating surface 31 for engaging edge 10 of sleeve 1 . Sliding collar 3 also defines mating surface 32 for engaging spring 5 (thereby positioning spring 5 between the locking and sliding collars). Circular grooves 33 and 34 are defined about an exterior surface of collar 3 . These grooves are employed for retaining wire 6 in its engaged and disengaged positions. Circular groove 33 retains the wire 6 in its disengage position whereas groove 34 retains the wire in its engaged position (i.e., for connecting sliding collar 3 to a mounting bracket).
FIG. 5 shows the spring assembly illustrated in FIGS. 1A-1D in an installed configuration including a cable. The parking brake cable shown can be of any suitable length and size depending upon the dimensions and weight of the vehicle. The cable comprises an exterior conduit and an interior strand. The cable includes a conduit end fitting that is received within the interior opening defined on the right hand side of the previously described sleeve. The strand within the conduit extends beyond the conduit end fitting and travels along the length of the sleeve and exits the sleeve on the left hand side of the sleeve. If desired, the parking brake cable can include one or more additional fittings for mounting the cable onto the vehicle (e.g., refer to item 48 in FIG. 5 ). The strand can also include a button (e.g., a zinc die-cast member) that defines the terminal end of the strand. This button also functionally engages either a member for applying a load (e.g., manual or electrically applied parking brake lever), or the parking brake system. Applying or releasing tensile forces in the cable causes the strand to move within the conduit thereby engaging or disengaging the parking brake system (e.g. drive line brake).
FIG. 5 illustrates spring assembly of FIG. 1 associated with a cable or strand assembly 40 . Assembly 40 comprises conduit 41 , protective straps 42 (that can be contacted by clamps, not shown, when installing the assembly), snap fitting 43 (e.g., such as illustrated in U.S. Pat. No. 4,131,379; hereby incorporated by reference), polyethylene sheath 44 , radius or end button 45 , strand 46 , and threaded end fitting 47 . End button 45 is received within a conventional parking brake apparatus (not shown) wherein operation of assembly 40 causes displacement of button 45 and in turn causes a brake apparatus to engage or release. The threaded end fitting 47 is connected to either another cable or directly to a system (e.g., foot pedal, over center lever, etc.) for operating assembly 40 . Assembly 40 is positioned at a predetermined location upon a vehicle and supported by bracket 48 . Bracket 48 can have any suitable configuration so long as it defines an opening, depression, cavity or other configuration for receiving the spring assembly.
The components of the inventive spring assembly can be fabricated by using any suitable methods. One example comprises employing conventional screw machine techniques. The components can be fabricated from conventional materials such as 12L14 steel, spring steel, among other materials.
While the above Description places particular emphasis on a spring assembly for usage in a vehicular parking brake system, the inventive spring assembly can be employed in a wide range of applications wherein it is desirable to preload or maintain a minimum force in a mechanical system. | The disclosure relates to a spring assembly for use in a parking brake system that solves problems associated with conventional parking brake systems. The disclosed spring assembly imparts a minimum force (e.g., tensile force) onto the parking brake cable of the parking brake system when the parking brake is applied. The spring assembly comprises a sliding collar, a wire ring located about the exterior diameter of the sliding collar, a locking collar, a spring and a sleeve for receiving the aforementioned components. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a surgical saw blade and corresponding clamp.
Orthopaedic procedures often require the use of powered bone saws. Commonly used is the oscillating saw which rapidly moves a flat, plate-like blade through an arc in front of the saw body. These powered saws operate at high speed and with large blade loads. Therefore, it is important that the blade be coupled to the saw in such a way as to eliminate, as far as possible, relative motion between the blade and the saw since such motion results in vibration, wear, heat and power loss.
SUMMARY OF THE INVENTION
The blade and clamp of this invention provide a motion free coupling while at the same time providing for easy placement and removal of the blade in and from the clamp.
The clamp has a first clamping face mounted within a housing and a second clamping face mounted within the housing parallel to the first clamping face. The two clamping faces define a space for receiving the blade. The second clamping face includes a plurality of lugs projecting toward the first clamping face. Each lug comprises a rectangular base portion adjacent the second clamping face and end walls and converging side walls extending away from the second clamping face. The rectangular base portion of each lug has a base axis parallel to the side walls. The lugs are located with their base axes in a radial pattern about an axis perpendicular to the first and second clamping faces.
The blade comprises a plate-like body having relatively broad parallel side surfaces and a relatively narrow edge extending around the body. The blade has an end portion for engaging the clamp assembly, the end portion having a primary U-shaped through slot between the side surfaces and opening to the edge of the blade. The blade further includes a plurality of radial U-shaped through slots. Each radial slot has a longitudinal axis projecting radially from a common axis which is perpendicular to the side surfaces and each radial slot opens to the primary U-shaped slot.
When the blade is positioned within the clamp and one of the clamping faces is moved to reduce the space between the clamp faces, the lugs engage the radial U-shaped through slots. As the lugs increasingly engage the radial slots, the converging side walls abut the radial slots and cause the blade to seat tightly onto the angled sides of the lugs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view of the clamp of the present invention.
FIG. 2 is top view of the second clamping face of the clamp of FIG. 1.
FIG. 3 is a side section view of the blade of the present invention.
FIG. 4 is a top view of the blade of FIG. 3.
FIG. 5 is an alternative embodiment of the blade of FIG. 4.
FIG. 6 is a top view of the blade of FIG. 3 seated on the second clamping face of FIG. 1.
FIG. 7 is a sectional view of the blade and second clamping face of FIG. 6.
FIG. 8 is a top view similar to FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a clamp assembly 1 for holding a plate-like blade in a powered bone saw includes a housing 2 and first 3 and second 4 clamping faces mounted within the housing and parallel to one another thereby defining a space between them.
The first clamping face 3 is rotatably mounted within the housing 2 by way of bearings 5 and a plunger 6. The plunger 6 is also capable of axial translation within the bearings 5 to increase and decrease the space between the clamping faces. A spring 7 biases the first clamping face 3 toward the second clamping face 4. A lever 8 is rotatably mounted on the housing 2 in axial alignment with the plunger 6. The lever 8 carries a pin 10. The plunger 6 contains an inclined slot 11 (shown in hidden lines) which engages the pin 10. When the lever 8 is rotated, the pin 10 rotates with it. As the pin 10 rotates, it moves within the inclined slot 11. However, the pin 10 is constrained within a horizontal plane so that as the pin 10 moves within the inclined slot 11 the plunger 6 moves upward thus moving the first clamping face 3 away from the second clamping face 4 and compressing the spring 7. The inclined slot 11 and the lever 8 together provide a mechanical advantage which magnifies a relatively low torsional force on the lever 8 into a relatively high compression force on the spring 7 so that high modulus springs can be used to provide high compression on the blade.
The second clamping face 4 is rotatably mounted within the housing 2 by way of bearings 13. A yoke 15 connects the second clamping face 4 to an input shaft 16. The input shaft 16 has an offset end 17 with an offset bearing 18. Rotation of the input shaft 16 causes the offset end 17 and offset bearing 18 to circumscribe a circular path. The yoke 15 follows the offset bearing 18 causing the second clamping face 4 to oscillate. The clamp faces 3 and 4 are locked to move together by use of an interlocking ball 12. The ball 12 is moveable in a groove 50 in the clamp extension 51 and held in place in a depression in the plunger 6.
Referring to FIG. 2, the second clamping face 4 includes a blade ring 19. The blade ring 19 comprises a plurality of connected lugs 20. The lugs 20 project away from the second clamping face 4 and toward the first clamping face 3. Each lug comprises an elongate base 21 portion adjacent the second clamping face 4. The base is preferably an elongate rectangular shape. End walls 22 and side walls 23 extend away from the second clamping face with the side walls 23 converging to form a truncated wedge. The elongate base portion 21 has a base axis 24 parallel to the side walls. The lugs 20 are located with their base axes 24 in a radial pattern about an axis 25 perpendicular to the first and second clamping faces.
Referring to FIGS. 3 and 4, a blade for use with the above described clamp comprises a plate-like body having relatively broad parallel side surfaces 30 and a relatively narrow edge 31 extending around the body. An end portion 32 is adapted for engaging the clamp assembly. The end portion 32 has a primary U-shaped through slot 33 between the side surfaces and opening to the edge of the blade 34. The end portion 32 further includes a plurality of radial U-shaped through slots 35 arranged about an axis 36 which is perpendicular to the side surfaces 30. The radial slots 35 open to the primary U-shaped slot 33.
FIG. 5 depicts an alternative embodiment of the blade of FIGS. 3 and 4 in which each radial U-shaped slot 37 has a width dimension 38 corresponding to the narrowest dimension perpendicular to its longitudinal axis 39 and parallel to the side surfaces 30. Each radial slot 37 further has a closed end 40 spaced from the primary U-shaped slot 33. The closed end 40 having a dimension wider than the width dimension 38 of the U-shaped slot. For example, the closed end 40 preferably forms a circular opening with a diameter larger than the width dimension 38 as shown. The alternative blade of FIG. 5 is useful where it is desired that the blade fit into the novel clamp of this invention as well as another clamp having circular pins for engaging the blade.
In use, the radial slots 35 of the blade engage the lugs 20 of the second clamping face 4 as shown in FIGS. 6 and 7. The first clamping face 3 presses against the top side surface 41 of the blade causing the radial slots 35 to engage the side walls 23 of the lugs 20. The radial slots 35 will engage the widening lugs 20 until the radial slots 35 are filled. Therefore, the clamp can accommodate blades with variations in slot dimensions and still grip such varying blades tightly. As the radial slots 35 engage the lugs 20, the lugs impart reaction forces 60 along the radial slots 35 directed normal to the longitudinal axes 39 of the radial slots 35 as depicted in FIG. 8. In the embodiment shown which has seven radial slots, the reaction forces are directed in the eight directions normal to the longitudinal axes of the radial slots. These reaction forces are represented as point loads shown as double headed arrows in FIG. 8, but are actually distributed along the bottom edge 70 of the radial slots 35. Because the reaction forces are directed in several directions, the blade is very stable in the clamp and the blade and clamp resist relative motion imposed by blade loads from any direction. In other words, pulling, pushing, and side loads on the blade are met by a supporting lug face and are countered in each instance by the diverging lug pattern. Also, because of the accommodating lug taper and radial lug pattern, blade loads are distributed evenly among the lugs.
A further advantage of this invention is increased safety. All of the moving parts of the clamp are contained within the housing. In use, the blade extends from the narrow slot in the front of the housing and the blade is the only exposed moving part. This lessens the likelihood of the saw operator being injured.
It will be understood by those skilled in the art that the foregoing has described a preferred embodiment of the present invention and that variations in design and construction may be made to the preferred embodiment without departing from the spirit and scope of the invention defined by the appended claims. | A blade and clamp obtain a motion free coupling while remaining easily operable. The clamp comprises first and second clamping faces. The second clamping face includes a plurality of tapered lugs arranged in a radial pattern. The blade comprises a plate-like body having a primary U-shaped slot and a plurality of radial U-shaped slots which engage the tapered lugs of the clamp to produce a tight motion free coupling between the blade and clamp. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to an optical servo-positioning system for positioning the read-out beam of an optical read-out system which reads out pre-recorded digital information from a recording medium such as a disc.
There has been a trend toward the development of digital recording and playback techniques. Video and audio signals previously recorded only in an analogue form, such as in conventional audio records or video tapes, are now being recorded in digital form on discs. Digital recording systems convert analogue information, such as, for example, an audio signal into digital information and then record that digital information onto a disc as "pits" forming a circular or spiral track of recorded information. The recorded information is read from a previously recorded disc by irradiating the spiral track with a read-out beam of convergent light, such as from a laser and then detecting the variation of a beam reflected from the disc.
In such optical digital information recording and read-out systems, it is an absolute necessity that the read-out beam be always accurately positioned over the data track being read so as to accurately sense the information recorded on the disc. This is sometimes referred to as maintaining the registration of the read-out beam.
Deviation of the incident read-out beam from the center of the track may cause the output of the reflected beam to be distorted or at too low an intensity to be sensed. As a result, the previously recorded information may not accurately read out. To prevent deviation or misregistration of the read-out beam, optical information read-out systems are usually provided with an optical servo-positioning system for positioning the spot of incidence of the read-out beam on the data track of the disc.
U.S. Pat. No. 4,118,735--Wilkinson--discloses a known optical servo-positioning system for positioning a read-out beam on a spiral data track. The system includes an articulated mirror for controlling the position of the light beam spot on the disc. An oscillator, which generates a low-frequency signal, drives the articulated mirror to wobble (dither) the spot so as to traverse the data track from one side of the track to the other with a very small lateral excursion. A photocell is positioned so as to detect a beam of light reflected from the data track. An output signal of the photocell includes error magnitude and direction information for the read-out beam. This magnitude and direction information is determined as a function of the phase relationship between the reflected light beam and the drive signal to the articulate mirror. If the beam is accurately centered, the intensity signal from the photocell is at a minimum. If the reflected beam is to the right of center of the data track, the intensity signal from the photocell increases, and, when multiplied by the driving signal, produces a product that has, for example, a positive value. However, if the reflected beam is to the left, the product of the intensity signal from the photocell and the driving signal has an opposite or negative value. Therefore, the direction of correction required is represented by the polarity of the multiplied signal while the amount of correction is represented by the articulate mirror.
However, known systems such as the Wilkinson system, discussed above, have the following problem. The wobbling frequency must be selected so as not to interfere with the information recorded on the disc. If the information recorded on the disc is a video signal which has the frequency spectrum of 1 to 5 MHz, the wobbling frequency of the servo-positioning system can be selected so as to be out of the video signal frequency spectrum band that is recorded, for example several 10 kHz. However, when the digital information recorded on the disc has an extended frequency spectrum range, such as from zero to several MHz, it is difficult to separate the wobbling signal from the pre-recorded signal so that they do not interfere with one another. Various modulation schemes such as NRZ (Non-Return to Zero), MFM (Modified Frequency Modulation), PM (Phase Modulation) and others are employed to convert an analogue signal into digital form for recording on a disc. These modulation systems have spectrum components in the low frequency band. Using known servo-positioning arrangements, a wobbling signal will interfere with these low frequency components. To prevent such interference, it would be necessary to degrade system performance by eliminating the low frequency components of the modulated digital data recorded on the disc.
SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to provide an improved optical servo-positioning system for a digital information read-out system which can separate the wobbling signal component from the digital information read from the data track of a disc and accurately position the read-out beam on the center of the data track being read from the disc.
In accordance with a preferred embodiment of the invention, there is provided an optical servo-positioning system for an optical read-out system which reads digital information from a previously recorded track of a recording medium comprising a light source; an irradiating means for irradiating a light beam from the light source on the recording medium to read out the digital information recorded on the recording medium; an oscillator for oscillating a certain frequency signal; a wobbling means for wobbling the light beam to traverse an information track by the oscillated signal; a photo detecting means for detecting the light beam reflected from the recording medium and producing electric signal; a waveform arranging means for arranging the output of the photo-detecting means in a pulse signal with a constant amplitude; an extracting means for extracting a clock signal component from the output of the waveform arranging means, said clock signal being a basic signal to modulate the information; a latch circuit for latching the output of the waveform arranging means synchronizing with the output signal of the extracting means; a subtracting circuit for subtracting the output of the latch circuit from the output of the photo-detecting means; a detecting circuit for detecting the output of the subtracting circuit; and an adding means for adding the output of the detecting circuit and the output of the oscillator.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following description taken in connection with the accompanying drawings, in which:
FIG. 1 schematically illustrates an optical digital information read-out system with an optical servo-positioning system according to the invention;
FIG. 2 shows an enlarged fragmentary perspective view of the disc track, illustrating information pits to be scanned by the light beam;
FIG. 3 shows the locus of the beam with respect to the track;
FIG. 4 shows an exemplary circuit of the pulse edge detection circuit shown in FIG. 1;
FIG. 5, consisting of 5A-5H, shows a graphical representation of voltage wave forms as they appear under certain conditions of operation of the subject invention;
FIG. 6 shows a graphical representation of voltage waveforms as they appear under certain conditions of operation of the present invention; and
FIG. 7 shows a relation between the change of amplitude of the read-out signal and the voltage of the control signal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals represent identical or corresponding parts throughout the several views, and more particularly to FIG. 1, there is shown a block diagram of an optical digital information read-out system according to the present invention. The system is intended to read information from an information disc 20 rotated at a constant speed by a motor 22. The surface of disc 20 has, arranged in substantially circular or spiral tracks in which digital information representing, for example, an audio signal has been pre-recorded in form of a series of pits 110 as shown in FIG. 2.
The pre-recorded information is read out by directing a light beam 24 along an optical path from a light source 26, such as a laser, through a beam splitter 28 and a quarter-wavelength (λ/4) plate 30 for polarizing the light beam, into a movable beam-deflecting mirror 32 driven by a tracking transducer 34. From mirror 32, light beam 24 is directed to an object lens 36 and onto an information track of disc 20 consisting of a series of pits 110 in the surface of the disc as shown in FIG. 2.
Light beam 24 is wobbled so as to traverse the data track in response to an oscillating signal which is applied to transducer 34. The moving track is scanned by wobbling beam spot 112 as shown in FIG. 3. Light reflected from the surface of disc 20, at the point where the spot of beam 24 is incident, is gathered by objective lens 36 which returns the beam towards beam splitter 28 via beam-deflecting mirror 32 and quarter-wavelength (λ/4) plate 30.
Beam splitter 28 directs reflected light beam 38 towards a photocell 40 such as a photodiode. Reflected light beam 38 from information disc 20 includes the information recorded as pits on disc 20 in the form of an intensity modulation of light. Reflected beam 38 also includes a wobbling signal. Since the information is in the form of intensity modulation, it can be read out by detecting the intensity of the reflected light beam with photocell 40 to form electrical signals. An output signal 42 of photocell 40 is delivered to a data processing circuit 44 through an optional high pass filter 46. Data processing circuit 44 processes the signal 42 from photocell 40 to obtain an analogue audio signal 48 defined by the digital data pre-recorded on the disc in the form of pits 110.
The signal output of the high pass filter 46 is also delivered to a comparator 50 which detects whether or not the voltage level of the output from high pass filter 46 is higher than a predetermined threshold voltage level and generates a fixed amplitude pulse each time the threshold level is exceeded. This converts the signal output of high pass filter 46 into the pulse signal comprising a plurality of pulses of constant amplitude.
The output signal of comparator 50 is coupled to a pulse edges detection circuit 52. Pulse edges detection circuit 52 is used to detect the leading and the trailing edges of the output pulse signal from comparator 50 so as to obtain a clock signal component from the read-out information. The clock signal corresponds to a basic signal used to modulate the information. An output of pulse edges detection circuit 52 is delivered to a phase locked loop (PLL) circuit 54. PLL circuit 54 produces an output signal that is phase locked to the pulse signal from pulse edges detection circuit 52 so as to eliminate any jitter and to fill in any missing pulses. The output of PLL circuit 54 is delivered to a latch circuit 56. Latch circuit 56 comprises D-type flip-flop and latches the output signal from comparator 50 by the output of PLL circuit 54 as a timing clock. It is necessary that the output of PLL circuit 26 be delayed a certain period of time with respect to the output of comparator 50 to insure latching the output of comparator 50. PLL circuit 54 includes a delay circuit to produce a delayed output.
An output of latch circuit 56, which is the pure information not including wobbling signal component, is delivered to a variable gain amplifier 58 which adjusts the amplitude of the output of latch circuit 56. An output 60 of variable gain amplifier 58 is delivered to one input terminal of a subtraction circuit 62. Output 42 of photocell 40 is delivered to the other input terminal of subtraction circuit 62. Subtraction circuit 62 subtracts the output 60 of variable gain amplifier 58 from output 42 of photocell 40. Output 60 of variable gain amplifier 58 includes pure information without any wobbling signal component. Output 42 of photocell 40 includes the information and wobbling signal component. Therefore, an output of subtraction circuit 62 is the pure wobbling signal component.
In FIG. 1, a level comparator 76 may be employed. This level comparator 76 compares the outputs level of photocell 40 and variable gain amplifier 58 and then generates a gain control signal for controlling the gain of variable gain amplifier 58 to make the output level of variable gain amplifier 58 equal to the output level of photocell 40.
Also shown in FIG. 1, an automatic gain control (hereafter AGC) circuit may be employed, which controls to make the output level of variable gain amplifier 58 equal to the output level of photocell 40. The AGC circuit includes a level comparator 76 which compares the output level of photocell 40 and variable gain amplifier 58 and delivers its output as a gain control signal to variable gain amplifier 58.
According to the AGC circuit, the output level of variable gain amplifier 58 and photocell 40 may always coincide even if the output level of photocell 60 changes because of a different kind of disc.
Referring now to FIG. 4, the pulse edges detection circuit 52 comprises a differential circuit 400 for differentiating the pulse to detect the leading edges thereof, a differential circuit 402 for differentiating the pulse inverted by an inverter 404 to detect the trailing edges thereof, an OR gate 406 for getting positive pulses, for example, from the output of the differential circuits 400 and 402, and a mono-multivibrator 408 which may be triggered by the outputs of differential circuits 400 and 402.
FIGS. 5A to 5H show waveforms for explaining the signal processing that occurs from comparator circuit 50 to subtraction circuit 62 of FIG. 1. FIG. 5A represents the basic clock pulses used in recording the information onto disc 20. The FIG. 5B waveform represents digital information which is generated synchronously with the clock pulse shown in FIG. 5A and recorded on the disc 20. The FIG. 5C waveform represents the output of photocell 40 as the digital information is read out by the wobbling light beam. The signal includes not only the digital information, but also a wobbling signal envelope.
The output of photocell 40 is delivered, via optional high pass filter 46, to comparator 50. Comparator 50 detects whether or not the voltage level of the output from photocell 40 is higher than the predetermined threshold voltage level and produces the pulse signal with a constant amplitude as shown in FIG. 5D. In essence, comparator 50 eliminates the wobbling envelope, leaving only the digital information signal. The output of comparator 50 is delivered to pulse edges detection circuit 52. Pulse edges detection circuit 52 produces a narrow pulse, as shown in FIG. 5E, whenever it detects a pulse edges of the output signal of comparator 50. The output of pulse edges detection circuit 52, which includes jitter and may not include a pulse corresponding to every original clock pulse, is delivered to PLL circuit 54. PLL circuit 54 eliminates the jitter and supplies missing pulses. As a result, the output of PLL circuit 54, as shown in FIG. 5F, is a stable clock signal without any jitter and with all clock pulses. The output of PLL circuit 54 is delivered to latch circuit 56.
Latch circuit 56 latches the output of comparator 50 responsive to the clock pulses from PLL circuit 54. As a result, the output of latch circuit 56 is a pure digital information signal having constant amplitude without any jitter and without any wobbling signal component. The output of latch circuit 56 is delivered to subtraction circuit 62 through variable gain controlled amplifier 58. Subtraction circuit 62 subtracts the gain adjusted output of latch circuit 56 shown in FIG. 5G from the output of photodiode 40 (see FIG. 5C). Therefore, the output of subtraction circuit 62 represents only pure wobbling signal component as shown in FIG. 5H.
In this manner, the wobbling signal component in its pure form is extracted from the output of photocell 40. This pure wobbling signal can be used to accurately position the read-out beam over the data track being read.
Referring again to FIG. 1, the output of subtraction circuit 62 is delivered to a synchronous detection circuit 64. Synchronous detection circuit 64 detects the output of subtraction circuit 62 in accordance with an output signal from an oscillator 68 which provides an oscillating signal for wobbling the beam-deflection mirror 32. An output of synchronous detection circuit 64 is delivered to an adder circuit 74 through a low pass filter 70 and an amplifier 72. Adder circuit 74 adds the output of amplifier 72 and the output 66 of oscillator 68, and then delivers the added signal to transducer 34. This signal, applied to transducer 34 includes the wobbling signal generated by oscillator 68 and an error signal component for correcting misregistration, the error component being generated by synchronous detection circuit 64, low pass filter 70 and amplifier 72.
Referring now to FIG. 6, a curve 600 represents the output of photocell 40 when the light beam is at various positions in the vicinity of the center 402 of the data track. When the beam is positioned directly over center line 602, the voltage produced therein is a maximum; but, as it moves either to the right or left of center line 602, the voltage produced therein is reduced. Therefore, when the center of the beam wobble 604 is positioned over center line 602, the output of subtraction circuit 62 is a waveform with small change of the amplitude shown by curve 606. But when the center of the beam wobble 604 is positioned either over the right or left of center line 602, the output of subtraction circuit 62 is a waveform with large change of the amplitude shown by curve 608 or 610. In addition, the output waveform 608 is phase inverted to the output waveform 610.
Therefore, a correction (error) signal for correcting the beam position is produced by detecting the output of subtraction circuit 62 shown in FIG. 7. The correction signal, combined with the oscillation output, is applied to the transducer 34 which drives the mirror 32, the latter being operable to deflect the light beam 24 in accordance with the correction signal. Thus, the beam position is always automatically adjusted to position over the center of the information track being read out.
As above-mentioned, according to the invention, only the wobbling signal component is accurately separated from the photocell signal which includes digital information and the wobbling signal component. By accurately separating the wobbling component, tracking control is very steady and the digital information is read out accurately.
Many changes and modifications in the above described embodiments, can, of course, be carried out without departing from the scope of the present invention, that invention intended to be limited only by the scope of the appended claims. | A servo-positioning system for controlling the positioning of a read-out light beam in an optical system which reads out digital information from a pre-recorded disc including a wobbling means for wobbling a read-out beam to traverse an information track of the disc, a photo detecting means for detecting the read-out beam reflected from the disc, a waveform arranging means for arranging the output of photo detecting means, an extracting means for extracting a clock signal component from the output of the waveform arranging means, a latch circuit for latching the output of the waveform arranging means synchronized with the output signal of the extracting means, a subtracting means for subtracting the output of the latch circuit from the output of the photo detecting means, to isolate the wobbling signal component from the output of the composite photo detecting means including an information component and a wobbling component. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part application of application, U.S. patent application Ser. No. 09/836,514, filed on Apr. 17, 2001. The co-pending parent application is hereby incorporated by reference herein and is made a part hereof, including but not limited to those portions which specifically appear hereinafter.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to gas generation and, more particularly, to devices and methods for inflating an inflatable device such as an inflatable vehicle occupant restraint of a respective inflatable restraint system.
[0003] It is well known to protect a vehicle occupant using a cushion or bag, e.g., an “airbag cushion,” that is inflated or expanded with gas such as when the vehicle encounters sudden deceleration, such as in the event of a collision. In such systems, the airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, the cushion begins to be inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as an “inflator.”
[0004] Many types of inflator devices have been disclosed in the art for the inflating of one or more inflatable restraint system airbag cushions. Prior art inflator devices include compressed stored gas inflators, pyrotechnic inflators and hybrid inflators. Unfortunately, each of these types of inflator devices has been subject to certain disadvantages such as one or more of having a greater than desired weight, requiring more than desired space or volume, producing undesired or nonpreferred combustion products in greater than desired amounts, and producing or emitting gases at a greater than desired temperature, for example. Further, in those inflator devices that rely upon the reaction of a gas generant material or fuel to produce or provide inflation gas, the cost of producing or supplying such gas generant material or fuel and associated inflator device may be greater than would otherwise be desired.
[0005] Thus, there remains a need and a demand for a gas generating device, particularly for application in an apparatus for inflating an inflatable device, and methods of inflation that more freely permit the use of lower cost reactant materials.
[0006] There has been and continues to be significant interest in gas generant compositions incorporation and use of ammonium nitrate. In particular, ammonium nitrate is a relatively low cost, readily available and generally high gas yield component material for inclusion in such compositions.
[0007] Unfortunately, the general incorporation and use of ammonium nitrate in pyrotechnic gas generant formulations have generally been subject to certain difficulties. For example, ammonium nitrate-containing pyrotechnic gas generant formulations have commonly been subject to phase or other changes in crystalline structure such as may be associated with volumetric expansion such as may occur during temperature cycling over the normally expected or anticipated range of storage conditions, e.g., temperatures of about −40° C. to about 110° C. Such changes of form or structure may result in physical degradation of such gas generant formulation forms such as when such a gas generant formulation has been shaped or formed into tablets, wafers or other selected shape or form. Further, such changes, even when relatively minute, can strongly influence the physical properties of a corresponding gas generant material and, in turn, strongly affect the burn rate of the generant material. Unless checked, such changes in ammonium nitrate structure may result in such performance variations in the gas generant materials incorporating such ammonium nitrate as to render such gas generant materials unacceptable for typical inflatable restraint system applications.
[0008] In view of the above, there is a need and a demand for a gas generating device, an apparatus for inflating an inflatable device and a method for inflation that enhance the likelihood of greater or more widespread use of reactant materials such as ammonium nitrate.
SUMMARY OF THE INVENTION
[0009] A general object of the invention is to provide an improved gas generation or inflation device and method for inflating an inflatable safety device.
[0010] A more specific objective of the invention is to overcome one or more of the problems described above.
[0011] The general object of the invention can be attained, at least in part, through an apparatus for inflating an inflatable safety restraint cushion and which apparatus includes a first container containing a supply of elemental carbon. The apparatus also includes a first chamber having contents including a supply of oxidant source material, wherein the oxidant source material comprises a supply of nitrous oxide. The apparatus further includes a container opener, an initiator device and a diffuser assembly. The chamber opener is effective upon actuation to open the first container and place at least a portion of the supply of elemental carbon in reaction communication with at least a portion the first chamber contents. The initiator device is effective to initiate reaction between at least a portion of the supply of elemental carbon and at least a portion the first chamber contents to form a gaseous inflation medium. The diffuser assembly includes at least one outlet opening for directing gaseous inflation medium discharged from the first chamber to the inflatable device.
[0012] The prior art has generally failed to provide an inflator device and inflation method that permits and facilitates the use of low cost fuel materials, such as elemental carbon, in gas generation or production and, in particular, for gas generation or production for use in the inflation of inflatable restraint system airbag cushions. The prior art also has generally failed to provide an inflator device and inflation method that may desirably facilitate or otherwise more easily permit the advantageous use of compounds such as ammonium nitrate without incurring undesired complications such as described above relating to form and structure on the ammonium nitrate and the resulting performance characteristics thereof.
[0013] The invention further comprehends an apparatus for inflating an inflatable safety restraint cushion. In accordance with one preferred embodiment of the invention, such an apparatus includes a first container having contents including a supply of elemental carbon, a supply of ammonium nitrate and a supply of boron potassium nitrate. The apparatus also includes a first chamber having contents including a supply of nitrous oxide and a supply of carbon dioxide; wherein the first chamber contents are contained therewithin in a static state in an at least partially liquified form. The apparatus further includes a container opener effective upon actuation to open the first container and place at least a portion of the supply of elemental carbon in reaction communication with at least a portion the first chamber contents. Also, the apparatus includes an initiator device effective to initiate reaction between at least a portion of the supply of elemental carbon and at least a portion the first chamber contents to form a gaseous inflation medium and a diffuser assembly including at least one outlet opening for directing gaseous inflation medium discharged from the first chamber to the inflatable device.
[0014] The invention still further comprehends a method of or for inflating an inflatable safety restraint cushion. In accordance with one such preferred embodiment of the invention, such method involves reacting elemental carbon with an oxidant within an inflator device to form a gaseous inflation medium and then directing at least a portion of the gaseous inflation medium flowing through at least one outlet opening out of the inflator device.
[0015] As used herein, the references to “elemental carbon” are to be understood to refer to generally refer to carbon in an uncombined form. It will be appreciated that elemental carbon in accordance with the invention may contain or include small or minor amounts of impurities, such as are known or commonly associated with carbon.
[0016] Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a simplified, partially in section, schematic drawing of an airbag inflator assembly in accordance with one embodiment of the invention.
[0018] [0018]FIGS. 2 and 3 are graphical depictions of tank pressure and internal pressure, each as a function of time, realized for the test inflator of Example 1.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention may be embodied in a variety of different structures. As representative, FIG. 1 illustrates the present invention as embodied in a gas generating device, generally designated by the reference numeral 10 . While such gas generating devices may find various uses, the invention is believed to have particular utility for generating gas such as may be used in the inflation of an inflatable vehicle occupant restraint, e.g., an inflatable airbag cushion, not shown. As is known and upon proper actuation, such inflatable vehicle occupant restraints are typically inflated by a flow of an inflation fluid, e.g., gas, from an inflator assembly to restrain movement of an occupant of the vehicle. In practice, it is common that the inflatable vehicle occupant restraints be designed to inflate into a location within the vehicle between the occupant and certain parts of the vehicle interior, such as the doors, steering wheel, instrument panel or the like, to prevent or avoid the occupant from forcibly striking such parts of the vehicle interior. As identified above, such gas generating devices are commonly referred to as inflator.
[0020] As will be described in greater detail below, inflator devices in accordance with the invention desirably generate inflation gas via the reaction of at least a portion of a supply of elemental carbon stored, contained or otherwise provided therein. Further, while the invention is described hereinafter with particular reference to an inflator for an airbag assembly such as for use in various automotive vehicles including vans, pick-up trucks, and particularly automobiles, it is to be understood that the invention also has applicability not only with various types or kinds of airbag module assemblies for automotive vehicles including driver side, passenger side, side impact, curtain and carpet airbag assemblies, for example, but also with other types of vehicles including, for example, airplanes, as well as possibly other inflation applications.
[0021] Returning to the FIG. 1, the inflator 10 is an assembly that comprises a pressure vessel 12 . The inflator assembly 10 includes an initiator device 14 , a first container 16 , a first chamber 20 , and a diffuser assembly 22 . The inflator 10 has a first end wall 24 that has an opening 26 therein. In the inflator assembly 10 , the initiator device 14 is desirably attached through the opening 26 in sealing relation, such as via a weld, crimp or other suitable hermetic seal.
[0022] In such an assembly, the initiator device can include any suitable type of initiator means including: bridgewire, spark-discharge, heated or exploding wire or foil, through bulkhead (e.g., an initiator that discharges through a bulkhead such as in the form of a metal hermetic seal), for example, and may, if desired, optionally contain a desired load of a pyrotechnic charge. As will be appreciated, in certain preferred embodiments of the invention, the exclusion or minimization of such pyrotechnic material may be desired or required in certain application such as so minimize or avoid particulate formation or introduction into the inflation fluid of the inflator device. As will be described in greater detail below, the inclusion or presence of such pyrotechnic material may, however, be desired in certain alternative preferred embodiments of the invention such as to more easily or readily provide a large heat input for associated reaction processing. In view thereof, as pyrotechnic charge-containing initiators can typically more easily produce such relatively large heat inputs from a relatively small sized initiator device, the practice of the invention with such initiators can be particularly advantageous. An initiator may provide such a large heat input through the inclusion therewith or therein of an additional quantity of pyrotechnic, i.e., a “booster charge,” such as boron potassium nitrate (BKNO 3 ), for example.
[0023] The first container 16 is generally situated adjacent the initiator device 14 in discharge communication therewith. In the illustrated static, at rest or “normal” condition or state, the first container 16 is closed and has contents, designated by the reference numeral 30 . The first container contents 30 include, in accordance with a preferred embodiment of the invention and as described in greater detail below, a quantity or supply of fuel material in the form of elemental carbon.
[0024] While practice of the invention in its simpler forms does not require that the first container contain or include materials other than elemental carbon, in accordance with certain preferred embodiments of the invention, the first container will desirably contain or include additional materials such as may assist or contribute to improving or facilitating performance of the inflator. Thus, in accordance with one preferred embodiment, the first container contents 30 may additionally include a quantity of ammonium nitrate, as detailed below. Alternatively or in addition, the first container 16 may, if desired, additionally contain or include an energetic or booster material such as composed of boron potassium nitrate (BKNO 3 ), for example. As will be appreciated, the presence or inclusion of an energetic or booster material such as composed of BKNO 3 may be desired where, for example, the initiator device 14 does not itself provide sufficient energy or heat to drive the desired reaction(s), such as described in greater detail below, to the degree desired. Thus, in accordance with certain preferred embodiments of the invention, the first container contents 30 include carbon and ammonium nitrate in the following mass basis percentages: generally 10-100% C and 0-90% ammonium nitrate; preferably 30-80% C and 20-70% ammonium nitrate and, more preferably, 40-50% C and 50-60% ammonium nitrate. Where the first container contents include a booster (e.g., BKNO 3 ), the first container contents 30 can desirably include carbon and ammonium nitrate mixture, as described above, and booster material in the following mass basis percentages: generally 20-100% carbon/ammonium nitrate and 0-80% booster; preferably 50-90% carbon/ammonium nitrate and 10-50% booster and, more preferably, 60-80% carbon/ammonium nitrate and 20-40% booster.
[0025] In accordance with certain preferred embodiments of the invention, the first container 16 may additionally contain a supply of powdered metal such as magnesium or aluminum, for example, or a metal hydride or the like, such as to increase therewithin contained and such as may serve to increase or improve reaction of such contents upon release and contact with the contents of the first chamber 20 .
[0026] In the illustrated static or at rest condition for the inflator 10 , the first chamber 20 is closed and has contents, designated by the reference numeral 34 , therein contained. The first chamber contents 34 desirably include a quantity of pressurized stored gas including a supply of oxidant source material composed, at least in part, by a supply of nitrous oxide. As detailed below, oxidant material derived from the oxidant source material may appropriately react with at least a portion of the elemental carbon fuel material to form or produce a supply of gaseous products such as may be used in the inflation of an associated inflatable airbag cushion.
[0027] In accordance with certain preferred embodiments of the invention, the first chamber contents 34 may desirably be composed a single oxidant source material, i.e., nitrous oxide, or be composed of nitrous oxide combined or mix with one or more other oxidant or oxidant source material and/or one or more materials that are typically inert under the conditions of interest. For example, suitable additional oxidant materials for inclusion in the first chamber contents 34 may include oxygen, for example. Further, the first chamber contents 34 may, if desired, additionally contain or include one or more inert materials such as argon, carbon dioxide or helium, for example. The first chamber contents 34 , in accordance with one preferred embodiment of the invention, consist essentially of an at least partially gaseous mixture of nitrous oxide and carbon dioxide.
[0028] Those skilled in the art and guided by the teachings herein provided will further appreciate that such pressurized or compressed contents can appropriately be stored or contained in the first chamber 20 in a gaseous, liquid or multi-phase form (i.e., partially gaseous and partially liquid mixture). As will be appreciated, the premium on size generally placed on modem vehicle design, generally results in a preference for smaller sized airbag inflators. In view thereof and the fact that the densities for such materials are significantly greater when in a liquid, rather than gaseous form, storage of such oxidant compressed gas materials at least partially in a liquid form may be preferred.
[0029] Thus, in accordance with one preferred embodiment of the invention, the first chamber contents 34 contain an at least partially liquified mixture of nitrous oxide (N 2 O) and carbon dioxide (CO 2 ). In particular, those inflator embodiments wherein the first chamber contents 34 include 5 to 95% N 2 O with the balance being CO 2 are generally preferred; those inflator embodiments wherein the first chamber contents 34 include 15 to 85% N 2 O with the balance being CO 2 are generally more preferred; and those inflator embodiments wherein the first chamber contents 34 include 20 to 60% N 2 O with the balance being CO 2 are generally even more preferred, where the percentages are in terms of molar percent.
[0030] Further, a leak trace material such as helium (He) can be added if necessary or desired for example for leak detection purposes, as is known in the art. In general, in those embodiments wherein helium is added it is generally preferred that such helium content be added or present in a relative amount of about 10 to 15 molar percent of the entire mixture or chamber contents.
[0031] In those inflator embodiments wherein the first chamber contents 34 include N 2 O, CO 2 and He, generally preferred content ranges for use in the practice of the invention include 5 to 85% N 2 O, 5 to 85% CO 2 and 10-15% He; more preferably, 15 to 75% N 2 O, 15 to 75% CO 2 and 10-15% He; and, even more preferably 20 to 60% N 2 O, 30 to 70% CO 2 and 10-15% He, with such percentages being on a molar basis.
[0032] The first chamber 16 is closed and the contents 34 thereof appropriately held therewithin from fluid communication with the diffuser assembly 20 by means of a closure 40 such as composed of a wall 42 with a burst or rupture disk 44 . Those skilled in the art and guided by the teachings herein provided will appreciate that closures of other suitable types or forms can desirably be used in the practice of the invention and the broader practice of the invention is not necessarily limited to particular or specific types or forms of closures.
[0033] The diffuser assembly 20 defines a diffuser chamber 46 and includes a plurality of diffuser orifices or outlet openings 50 for dispensing inflation gas from the inflator 10 into an associated inflatable airbag cushion (not shown).
[0034] While the broader practice of the invention is not necessarily limited to the specific or particular form of elemental carbon contained within the subject inflator device, the use of a finely powdered form of elemental carbon may assist in improving the reactability of the carbon and is thus currently believed preferred. In general, the invention can desirably be practiced employing elemental carbon in allotropic forms, e.g., graphite, and in amorphous (e.g., non-crystalline) forms such as charcoal or coal, for example. It is known to form activated carbon via various processing techniques and such as may serve to remove various impurities from the carbon. In general, activated carbon is a preferred material for use in the practice of the invention.
[0035] In accordance with one preferred embodiment of the invention, carbon may be oxidized directly in a nitrous oxide-based system according to the following reaction:
C+2N 2 O CO 2 +2N 2 (1)
[0036] Thus, the invention in one of its simpler forms relies on the reaction of elemental carbon with nitrous oxide to form or produce inflation gas such as may be used in the inflation of an associated inflatable device.
[0037] Elemental carbon, however, also reacts with water via the following relatively high gas producing reaction:
C+H 2 O CO+H 2 (2)
[0038] Both carbon monoxide and molecular hydrogen are potential fuels to be oxidized by or with nitrous oxide.
[0039] As identified in the above-identified parent patent application, Ser. No. 09/836,514, filed on Apr. 17, 2001, ammonium nitrate, in addition to having a relatively low cost, ready availability and high gas yield, will at high temperatures, e.g., temperatures of about 212° C. or more, decompose to produce water and additional nitrous oxide in accordance with the following idealized reaction:
NH 4 NO 3 N 2 O+2H 2 O (3)
[0040] As will be appreciated, such reaction has a relatively high molar ratio of products to reactants (3:1). Further, in such application as in the subject invention, the phase stability of an included ammonium nitrate is generally of no import as the ammonium nitrate is simply being decomposed.
[0041] Further, carbon monoxide, such as formed upon reaction of carbon with water, may react vigorously with nitrous oxide, in accordance with the following reaction:
CO+N 2 O CO 2 +N 2 (4)
[0042] In view of the above reactions (1) through (4), it can be seen that an elemental carbon-based system, particularly in combination with nitrous oxide and especially in further combination with ammonium nitrate, can be particularly attractive in inflatable restraint system inflator device applications.
[0043] Further, those skilled in the art and guided by the teachings herein provided will appreciate that inflator performance parameters such as rise rate, internal pressure and peak output pressure, for example, can desirably be controlled, at least in part, via design parameters such as particle size and load of elemental carbon therein contained, as well as the specific carbon containment method used and the presence or inclusion as well as amount and form of any booster material and ammonium nitrate, for example.
[0044] In operation such as upon the sensing of the occurrence of a collision, an electrical signal is sent to the initiator device 14 . The initiator device 14 functions and when it is a pyrotechnic-containing initiator, discharges high temperature combustion products into the first container 16 and, more specifically, the contents 30 thereof and such as to cause the rupture or otherwise opening of the container 16 such as to place the container contents 30 in communication with the chamber contents 34 .
[0045] At least a portion of the elemental carbon originally contained within the first container 16 will react with nitrous oxide originally contained within the first chamber 20 or otherwise react to form or produce gaseous inflation products. Additional gaseous inflation products may be formed or produced via the inclusion or presence of ammonium nitrate, water, and carbon dioxide, for example, such as may be supplied, formed or produced within certain preferred embodiments of inflator devices in accordance with the invention, as described above.
[0046] When the gas pressure within the first chamber 20 exceeds the structural capability of the burst disk 44 , the disk ruptures of otherwise permits the passage of the inflation gas into the diffuser chamber 46 and thus allows this gaseous inflation medium to exit through the diffuser orifices or outlet openings 50 into an associated airbag assembly.
[0047] The present invention is described in further detail in connection with the following examples which illustrate or simulate various aspects involved in the practice of the invention. It is to be understood that all changes that come within the spirit of the invention are desired to be protected and thus the invention is not to be construed as limited by these examples.
EXAMPLE
[0048] In this Example, a test inflator similar in design to the inflator 10 , as shown in FIG. 1, and sized for a passenger inflatable restraint device was used.
[0049] The test inflator had an internal volume of 266.3 cc and contained a 150 gram load of a 60/40 (molar) nitrous oxide and carbon dioxide combination. The initiator contained 460 mg of titanium hydride potassium perchlorate (THPP). The container “16” contained: 1.0 gram of carbon (average particle size of about 290 μm diameter), 6.7 grams of ammonium nitrate (average particle size of about 1000 μm diameter) and 3.0 grams of BKNO 3 (average particle size of about 50 μm diameter). The container contents has an approximate bulk density of 0.59 g/cc. The container “16” was hermetically sealed and about 70% filled with material (e.g., the container had about 30% void space). The test inflator has a total outlet opening area of 0.582 cm 2 .
[0050] The test inflator was fired into a test tank having an internal volume of 100 liters.
[0051] The test inflator produced about 4 moles of gas output. FIGS. 2 and 3 are graphical depictions of tank pressure and internal pressure, each as a function of time, realized for the test inflator of Example 1.
[0052] Results
[0053] The tank pressure and internal pressure, each as a function of time, shown in FIGS. 2 and 3 are indicative of an inflator employed for passenger applications. These results indicate that even though certain design parameters such as elemental carbon particle size, chamber and container content compositions and loads may not yet be fully optimized, the invention has wide potential application and utility.
[0054] Thus, the invention provides an inflator device and inflation method that permits and facilitates the use of low cost fuel materials, such as elemental carbon, in gas generation or production and, in particular, for gas generation or production for use in the inflation of inflatable restraint system airbag cushions. The invention also provides an inflator device and inflation method that desirably facilitates or otherwise more easily permits the advantageous use of compounds such as ammonium nitrate without incurring undesired complications such as described above relating to form and structure on the ammonium nitrate and the resulting performance characteristics thereof.
[0055] The invention illustratively disclosed herein suitably may be practiced in the absence of any element, part, step, component, or ingredient which is not specifically disclosed herein.
[0056] While in the foregoing detailed description this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purposes of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention. | Inflation apparatuses and methods are provided which utilize elemental carbon and nitrous oxide in the gas generation or formation process. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of verifying the reliability of the controlled end effector pose in robots, especially with regard to the minimal back-up configuration required to assure a statistically acceptable level of reliability of the robot pose.
BACKGROUND OF THE INVENTION
[0002] Robotic systems have been recently entered the medical arena for enhancing the surgeons' ability to precisely and minimally invasively position surgical tools. In particular, they have been used for remote manipulation (e.g. the daVinci® system supplied by Intuitive Surgical Inc., of Sunnyvale, Calif.), as semi active devices for brain biopsies applications (the NeuroMate™ system, supplied by Integrated Surgical Systems Inc., of Davis, Calif.) and as an active robot for hip and knee replacement (e.g. the ROBODOC® system, supplied by Integrated Surgical Systems Inc., of Davis, Calif.).
[0003] Failure of a positional control component could have serious repercussions in such hazardous tasks. In order to increase system reliability, prior art surgical robots have often been equipped with a double set of encoders or position sensors, these being the components that measure joint motions and provide the inputs for the control algorithms that determine the surgical tool position and orientation, i.e. the robot pose, and hence the motion path. The double set of sensors serve as a backup in case of an encoder failure. A discrepancy between the reading on the control encoder and its parallel back-up encoder immediately points to the failed sensor.
[0004] In serial type robots, where the links and joints are connected in series, each joint actuator affects the end-effector location serially and there is generally no internal position sensor that measures the end-effector location. Hence each encoder needs to be backed up by a second encoder on the same axis.
[0005] In a parallel type robot, on the other hand, and also in hybrid parallel-serial robots, it is possible to directly measure the end-effector location relative to the base and hence to locate a second set of back-up sensors not necessarily at the joints themselves but rather between the base and the output end-effector.
[0006] In the PCT application entitled “Precision Robot with Parallel Kinematics and a Redundant Sensor System” to M. Wapler, published as International Publication No. WO 01/19272, it is suggested that for a parallel robot with six degrees of freedom, it is possible to provide an acceptably safe backup for sensor failure using a minimum of three additional sensors disposed between the base and the moving platform.
[0007] However, since the cost of each position sensor and its associated control circuitry, is not insignificant, and even more importantly, since the space available in such miniature robots is at a premium, it would be desirable to devise a simpler method of providing back-up information for such robots, yet still providing an adequate safety margin.
[0008] The disclosures of each of the publications mentioned in this section and in other sections of the specification, are hereby incorporated by reference, each in its entirety.
SUMMARY OF THE INVENTION
[0009] The present invention seeks to provide a new apparatus and method for assuring effective backup for sensor failure in robots, by utilizing only a single extra sensor attached between the end actuator and the base. The use of such a single extra sensor provides effective back up that may be considered statistically significant for common applications, for any sensor/encoder failure occurring anywhere in the system, whether in one of the sensors associated with the actuating links or hinges of the robot, or in the extra sensor itself.
[0010] The use of a single additional sensor effectively provides the robotic system with one redundant information input to the robot control algorithm, which can be used in order to determine whether any of the other control sensors, or even the additional sensor itself, has failed and is delivering an erroneous reading, and hence to warn the operator of the failure. Furthermore, the use of a single additional sensor is able to provide useful warning of the simultaneous failure of two sensors or more, given that the likelihood that two sensors or more fail simultaneously in a mode that makes the failures undetectable, is so small that it can be regarded as statistically insignificant, and hence, within the safety requirements of such robots, even for use in surgical procedures. The method and apparatus of the present invention may be applied for use in robots having any number of degrees of freedom, and the additional sensor generally provides one redundant measurement over and above that provided by the number of sensors necessary for the degrees of freedom of the particular robot. Furthermore, the sensors utilized in the present invention, whether for determining the status of the actuating links or hinges of the robot, or whether the additional sensor itself, may be either length sensors, or angular sensors, or a combination thereof. If a length sensor, then the status of the actuator link determined is its length; if an angular sensor, then the status determined is the angular orientation of the associated link or hinge.
[0011] Throughout the present application, the terms encoder and sensor are often used interchangeably, even though more formally, the sensor is any device used to ascertain a link length or a joint angle, and an encoder is a device for providing a digital output signal according to the length or angle detected by the device. However, it is to be understood that when these different terms are used in this application, it is generally for the convenience of functional differentiation, and that the terms are understood to be equivalent and interchangeable in practice, and are thuswise claimed.
[0012] There is thus provided in accordance with a preferred embodiment of the present invention, a robot comprising a base member, a moving platform operative as the end effector of the robot, a plurality of adjustable links connecting the base member to the moving platform, the status of each of the adjustable links being known by means of a sensor associated with each of the links, and a single additional sensor connected between the base member and the moving platform. At least one of the adjustable links of the robot may preferably be a linear extensible link, in which case the sensor associated therewith is a length sensor. Alternatively and preferably, at least one of the adjustable links may be an angular rotational hinge, in which case the sensor associated therewith is an angular sensor. In the above mentioned robot, the single additional sensor may preferably be either a length sensor or an angular sensor.
[0013] There is further provided in accordance with yet another preferred embodiment of the present invention, a robot as described above, and also comprising a controller which verifies at least one of the position and orientation of the moving platform as determined by the sensors associated with each of the plurality of links, by means of the output of the single additional sensor. The controller then preferably provides an absolute verification of at least one of the position and orientation of the moving platform in the event that any one sensor is providing an erroneous output.
[0014] Additionally and preferably, the controller may provide a verification having a statistically insignificant probability of falsehood, of at least one of the position and orientation of the moving platform, in the event that two or more sensors simultaneously provide erroneous outputs. In the latter case, the maximum value of that statistically insignificant probability is the product of the square of the probability that one sensor is providing an erroneous output divided by the number of incremental positions in that one of the sensors having the least resolution.
[0015] In accordance with still another preferred embodiment of the present invention, in any of the above-mentioned robots, the plurality of extensible links may preferably be six links, and the single additional sensor a seventh sensor, or the plurality of links may preferably be four links, and the single additional sensor a fifth sensor, or even more generally, the single additional sensor is one sensor more than the number of degrees of freedom of the robot.
[0016] There is further provided in accordance with still other preferred embodiments of the present invention, a robot as described above, and wherein the robot is either a parallel robot, or a hybrid series-parallel robot.
[0017] In accordance with a further preferred embodiment of the present invention, there is also provided a method of verifying the positional reliability of a robot, comprising the steps of providing a robot comprising a base member, a moving platform operative as the end effector of the robot, and a plurality of adjustable links connecting the base member to the moving platform, the status of each of the adjustable links being known by means of a sensor associated with each of the links, and connecting a single additional sensor between the base member and the moving platform between predetermined points thereon.
[0018] There is also provided in accordance with yet a further preferred embodiment of the present invention, the method as described above, and also comprising the step of verifying by means of a controller that at least one of the position and orientation of the moving platform determined by the sensors associated with each of the plurality of links, is consistent with the corresponding relative position or orientation of the predetermined points as determined by the single additional sensor.
[0019] In either of the above mentioned methods, at least one of the adjustable links may preferably be a linear extensible link, in which case the sensor associated with the linear extensible link is a length sensor. Alternatively and preferably, at least one of the adjustable links may be an angular rotational hinge, in which case the sensor associated therewith is an angular sensor. In any of the above mentioned methods, the single additional sensor may preferably be either a length sensor or an angular sensor.
[0020] In the above described methods involving use of the controller for the verification step, the controller preferably provides an absolute verification of at least one of the position and orientation of the moving platform in the event that any one sensor is providing an erroneous output.
[0021] Additionally and preferably, the controller may provide a verification having a statistically insignificant probability of falsehood, of at least one of the position and orientation of the moving platform, in the event that two or more sensors simultaneously provide erroneous outputs. In the latter case, the maximum value of that statistically insignificant probability is the product of the square of the probability that one sensor is providing an erroneous output divided by the number of incremental positions in that one of the sensors having the least resolution
[0022] In accordance with still another preferred embodiment of the present invention, in any of the above-mentioned methods, the plurality of extensible links may preferably be six links, and the single additional sensor a seventh sensor, or the plurality of links may preferably be four links, and the single additional sensor a fifth sensor, or even more generally, the single additional sensor is one sensor more than the number of degrees of freedom of the robot.
[0023] There is further provided in accordance with still other preferred embodiments of the present invention, a method as described above, and wherein the robot is either a parallel robot, or a hybrid series-parallel robot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:
[0025] FIG. 1 shows a schematic illustration of an exemplary prior art parallel robot with six extensible links, and a length sensor on each link;
[0026] FIG. 2 illustrates schematically the parallel robot shown in FIG. 1 , but adapted according to a preferred embodiment of the present invention, by the addition of one extra sensor attached between the moving platform and the base platform;
[0027] FIG. 3 shows schematically two links and the 7 th sensor of a six-link parallel robot of the type shown in the embodiment of FIG. 2 , in a situation when two sensors provide erroneous output readings;
[0028] FIG. 4 illustrates schematically the application of the methods of the present invention to a further preferred type of parallel robot with four extensible links, and having one extra sensor attached between the base member and the end effector, and
[0029] FIG. 5 is a perspective view of the kinematic configuration of a further robot type, having a hybrid series-parallel configuration, showing the application of the methods of the present invention to such a robot.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] Reference is now made to FIG. 1 , which illustrates schematically a prior art exemplary parallel robot, with six extensible links 10 . Each of the six extensible links is connected between the base platform 12 and the moving end-effector platform 14 , preferably by means of a spherical joint at one end of the link and a U-joint at the other. In addition, each link length is measured by means of a position or length sensor 16 that moves with the link, and which provides a feedback signal to the robot control system indicating the length of the link, and hence, in combination with the information from the other link sensors, the position and orientation (pose) of the moving platform 14 . The prior art methods of ensuring the reliability of the robot position are either to double-up each sensor 16 with a back-up sensor fixed adjacent to the primary sensor on each link, the sole purpose being to provide a one-to-one back-up for each sensor, or, according to the methods described in the above mentioned International Publication No. WO 01/19272, to add three or more sensors connected between the base platform 12 and the moving platform 14 . Either of these solutions is expensive in terms of available space and cost.
[0031] Reference is now made to FIG. 2 , which illustrates schematically the parallel robot shown in FIG. 1 , but adapted according to a preferred embodiment of the present invention, by the addition of one extra sensor, the 7 th sensor, 20 , attached between the moving and the base platform, preferably in their central regions, such that it measures the distance between the attachment points on the moving and the base platforms. This extra sensor enables absolute verification of the moving platform location if one sensor fails, and statistically reliable verification of the moving platform if two or more sensors fail.
[0032] Changing the lengths of the extensible links generally changes the distance between the platform centers, and this change is detected by the 7 th sensor. The data from this 7 th sensor is passed, preferably through a connector in the base to the robot control system 22 , together with all of the encoder outputs from the six extensible links, and the data is compared for compatibility. Since the moving platform to which the 7 th sensor is connected is a rigid body, the length of the 7 th sensor is uniquely determined by the known length of the six links and hence provides backup information in the case of incorrect platform position. If as a result of a sensor failure, the moving platform is sent to a position other than that defined by the six sensor readings, then the 7 th sensor will provide an inconsistent readout, and the controller 22 thus provides warning of a sensor failure. Likewise, failure of the redundant 7 th sensor will cause it to provide a readout inconsistent with the output information provided by the other six sensors. Though a length sensor is a particularly convenient configuration for the 7 th sensor, and such a length sensor is used to illustrate the various preferred embodiments of the present invention, it is to be understood that the invention is not meant to be limited to use of a length sensor as the additional sensor, and that it is also implementable using an angular sensor as the additional sensor.
[0033] There are a number of situations where a single additional sensor will not detect any unwanted platform motion in the event of a link sensor failure. One such situation arises if all of the six link sensors fail and all provide false readings off by amounts such that the moving platform changes its rotational orientation about an axis through its center, while keeping its center fixed, and hence the 7 th sensor will provide an unchanged and correct length readout.
[0034] Similarly, if three of the sensors fail, and the other three fail symmetrically by an equal amount but in the opposite sense, then the moving platform might perform a pure rotation about its diametric axis, which will not be detected by the 7 th sensor, if the 7 th sensor is a length sensor, but may be detected if the seventh sensor is an angular sensor, depending on the type of angular sensor.
[0035] The use of a 7 th sensor, according to the preferred embodiments of the present invention, is only a practical back-up system for sensor failure, if it can be shown that the likelihood of the occurrence of combinations of sensor and sensor failures that are not detected by the 7 th sensor is so low as to be statistically insignificant.
[0036] In order to ascertain this likelihood, a number of failure scenarios are now analyzed. Firstly, the case of a single link sensor failure is investigated. In this situation, when the actuator moves, changing its associated link length, the control loop is closed with an erroneous position signal generated by the faulty sensor. The cases in which such an error is not detected by the 7 th sensor are now analyzed.
[0037] In order to identify these problematic cases, the moving platform trajectories that maintain the 7 th sensor reading constant should be calculated. When this is done, it is determined that there may be some situations in which the robot has one or more points of singularity. Such singular configurations, as they are known in the art, arise either when the robot cannot physically get to a commanded point, in which case the robot is said to have lost one degree of freedom, or when the robot loses control of the moving platform, which can undergo a displacement even while all the actuators maintain their length, in which case the robot is said to have gained one extra degree of freedom. Most practically used robots, including the 6-link parallel robot used to describe this preferred embodiment of the present invention, are designed in such a way that all of the possible singular configurations are outside of the robot work envelope.
[0038] However, when one sensor or sensor fails, there are still six known measured distances between the platforms, namely five link-length sensors and the 7 th sensor. This constitutes a “new” robot where the six link lengths are measured at different locations at the platforms in relation to the locations of the six links in the original robot. If this “new” robot contains singular configurations within the original robot work volume, the moving platform is able to move without being detected by the 7 th sensor, and the backup system is therefore useless.
[0039] If, however, no singular configurations exists within the “new” robot work volume, then any unplanned platform motion generated by an erroneous link-length sensor, is positively detected by the 7 th sensor. This is true since otherwise, there would be two different distinct solutions for the link lengths for the same position and orientation of the moving platform, as determined up to a single assembly mode by the inverse kinematics from the 5 link-length sensors and the 7 th sensor. The robot can switch assembly modes only when it passes through a singular configuration, which has been defined above as being out of the working envelope.
[0040] In order to determine what the singular configurations of the “new” robot are, it is necessary either to conduct an analytical analysis, such as by one of the methods described, for instance, in the article “Singular configurations of parallel manipulators and Grassmann geometry” by J -P. Merlet, published in Int. J. of Robotics Research , Vol. 8(5), pp. 45-56, October 1989, or in the article “Determination of the presence of singularities in a workspace volume of a parallel manipulator” by J -P. Merlet, published in “ NATO - ASI, Computational methods in mechanisms” edited by Sts. Konstantin and Elena Resort, 16-28 Jun., 1997, or in the article “Singularity analysis of closed-loop kinematic chains” by C. Gosselin and J. Angeles, published in IEEE Transactions on Robotics and Automation, Vol. 6, No. 3, June 1990, or in the Ph.D. Thesis on “Design Parameters of Parallel Manipulators” by R. Ben-Horin, The Technion, Israel, 1998, or alternatively, to conduct a search of the entire workspace of the manipulator.
[0041] If it is found that such singular configurations do not exist within the robot workspace, it can be concluded that there is no possible motion of the robot that can go undetected by the 7 th sensor if only one sensor fails.
[0042] The situation is now considered in which two sensors or sensors fail simultaneously. The likelihood of such an occurrence is very low. Moreover, even if two sensors fail at the same time and give erroneous readings, this is also detected by the 7 th sensor, unless the values given by the two failed sensors are in such a proportion that they just happen to match a valid displacement of the moving platform as determined by the other sensors and the 7 th sensor.
[0043] This situation is illustrated schematically in FIG. 3 , which shows two links 30 , 32 , and the 7 th sensor 34 of a six-link parallel robot of the type shown in the embodiment of FIG. 2 . The “correct” position of the moving platform 14 is shown as a full line. Due to the incorrect output reading of the sensor of the right hand link 30 , the control system is provided with a signal from this sensor that makes the control system believe that the moving platform is in the tilted position 14 ′, as indicated by the dotted lines, while the 7 th sensor 34 outputs correctly that its length has not changed, as the moving platform has performed a tilt about the point of attachment of the 7 th sensor. However, such an incorrect position of the moving platform would be detected by the sensor of the left hand link 32 , since its position would be inconsistent with the output of the left hand link sensor, which expects to detect the platform in the dotted position 14 ′, but actually finds it in the “correct” full line position 14 . The failure of the right hand link sensor is thus detected, unless the sensor of the left hand link 32 also fails, and in such a manner that it outputs a reading which exactly simulates that which would be obtained from the moving platform in its apparently tilted dotted position 14 ′.
[0044] In particular, when the location of the moving platform is defined by only 5 distance readings (4 link-lengths and the 7 th sensor), then it is not fully defined and the platform might move freely and have an infinite number of locations. Now whatever the reading of one failed sensor, it incorrectly defines the position of the moving platform, since the situation is effectively the same as the previous case with only one failed sensor. Whatever the first failing sensor reading is, there are now six other readings, the five correctly reading sensors and the seventh one. This uniquely determines the location of the platform (up to assembly mode) and hence we are at the same point as the analysis of one sensor failing, and can continue from that point by noting that for one sensor failing there is no way it can go undetected. This means that there is only one combination within the current assembly mode, of the two failed sensors that match the remaining five correctly operating sensors.
[0045] Based on the above analysis, the probability that the platform undergoes a movement without being detected by the 7 th sensor when either one or two sensors fail simultaneously may be calculated by the following procedure:
[0000] (i) It should be ensured that there are no singular points of operation within the entire robot workspace, in a robot composed of 5 link-length sensors and the 7 th sensor.
(ii) If this is confirmed, the probability that one sensor may fail is determined.
(iii) The probability that two sensors fail simultaneously is then the square of the probability that one may fail.
(iv) The probability that two sensors fail simultaneously and give a valid reading is the square of the probability of one failing times the reciprocal of the number of increments in one sensor, since there is a probability of one out of that number of increments that the incorrect failed reading will, by chance, be equal to the expected “correct” reading. The above calculation applies when all of the sensors have the same resolution, i.e. number of increments. If different sensors of the robot have different resolutions, then the highest probability of obtaining a valid reading when two sensors fail simultaneously, is given by the square of the probability of one failing times the reciprocal of the number of increments in the sensor with the lowest resolution.
[0046] In order to provide an estimate of the order of such a probability, an exemplary calculation is made for the SpineAssist miniature surgical robot, supplied by Mazor Surgical Technology Ltd., of Caesarea, Israel. For this robot, the encoder/sensor life time is given as 10,000 hours. The probability of one encoder/sensor failing during an operation that lasts for one hour is thus 10 −4 . The sensor resolution is 12 bit, i.e. 4096 incremental steps. Hence the probability, p, that an incorrect motion remains undetected by the 7 th sensor, as a result of two failed sensors is given by:
[0000] p= 10 −4 ×10 −4 ×4096 −1 =2.44×10 −12
[0000] The planned lifetime of each robot is 500 hours; hence the probability of an undetected platform motion arising from the simultaneous failure of two sensors, during the entire robot lifetime is p=1.22×10 −9 .
[0047] The above calculation is based on the expected lifetime of the encoder/sensors only. Taking into consideration that the encoder/sensor reading is also affected by other factors, such as the A/D converter, the encoder card and the power supply, the probability for a single sensor error reading during a one hour surgical procedure might be reduced by as much as an order of magnitude, to 10 −3 . Hence the probability for an incorrect motion remaining undetected by the 7 th sensor due to two failed sensors is then given as:
[0000] p= 10 −3 ×10 −3 ×4096 −1 =2.44×10 −10
[0000] During the robot lifetime of 500 hours, the probability is p=1.22×10 −7 . Noting that during these 500 hours, 500 surgical procedures will be performed by the robot, the probability of such an undetected failure in a single operation is 2.44×10 −10 . This is equivalent to the probability that if the robot is used for performing such a one hour surgical procedure on every one of the earth's current population, then using the 7 th sensor back-up system of the present invention, only one undetected failure arising from a double sensor failure will be statistically expected.
[0048] The probability that three or more sensors fail without being detected by the use of the 7 th sensor, is, of course, even smaller than the probability that two sensors fail without this being detected.
[0049] Reference is now made to FIG. 4 , which illustrates schematically the application of the methods of the present invention to a further preferred type of parallel robot, similar to that described in U.S. Pat. No. 6,837,892 for “Miniature Bone-mounted Surgical Robot” to the inventor of the present application. The parallel robot shown in FIG. 4 has a base member 40 , to which are flexibly connected four extensible links 42 , each with their own length sensor installed, and which provide controlled motion to the end effector, which is preferably shown in FIG. 4 as a guide tube 44 supported by two ring joints 46 whose position is moved by extension of the links 42 . A tool can be inserted through the guide tube 44 and maneuvered to the desired position. A fifth sensor 48 is attached between a known point on the base member 40 and a known point on the end effector 46 , and the output of this 5 th sensor is utilized, in the same way as is described hereinabove with respect to the 7 th sensor in the six-link robot of FIG. 2 , to provide back-up information to verify the position of the end effector provided by the four extensible link sensors.
[0050] Reference is now made to FIG. 5 , which is a perspective view of the kinematic configuration of a further robot type, having a hybrid series-parallel configuration. FIG. 5 illustrates schematically the application of the methods of the present invention to such a hybrid robot configuration. The robot is similar in mechanical structure to that described in the article entitled “Kinematic Structure of a Parallel Robot for MEMS Fabrication” by H. Bamberger and the inventor of the present application, and published in Advances in Robot Kinematics, ARK, Italy, 2004, and which has three linear motors, and also to that described in a paper by the same authors entitled “A New Configuration of a Six Degrees-of-Freedom Parallel Robot for MEMS Fabrication” presented at the IEEE International Conference on Robotics and Automation, (ICRA 2004), New Orleans, La., USA, and which has six linear motors. However, the preferred robot configuration shown in FIG. 5 differs from the first above-mentioned robot in that, besides the three linear motors located at the base of the robot, it also comprises an angular actuator in each of its jointed arms, such that the moving platform is endowed with a total of six degrees of freedom.
[0051] In the preferred embodiment of FIG. 5 , the fixed robot base 52 , is connected to the moving platform 54 , by means of three articulated legs. Each leg preferably has three arms, each arm including one linear motor and one rotational motor. Thus, leg A 1 , B 1 , C 1 , P 1 , is attached to the base at point A 1 , which is moved in the plane of the base by means of a linear motor, has an angular rotational motor, preferably at revolute hinge B 1 , a passive revolute hinge at C 1 , and is connected to the moving platform 54 at point P 1 . Such a robotic structure is not a pure parallel configuration, because of the action of the additional links and joints connected in each loop, whose effect is serial to the motion imparted to each leg by the linear motors at the base. In such a hybrid configuration, the combination of the sensors on the parallel linear motors and on the serial angular actuators together define a unique position of the moving platform end effector. According to this preferred embodiment of the present invention, the robot shown in FIG. 5 includes an additional redundant sensor 50 , connected between a point O in the central region of the base, and a point P on the central region of the moving platform. This 7 th sensor is operative to provide verification information about the expected moving platform position. Failure of one or more motor encoders/sensors, whether linear or rotational, will be detected by the additional redundant sensor, in a similar manner to that described above for the pure parallel robot configurations.
[0052] It is to be understood that the robotic configuration shown in FIG. 5 is only one preferred embodiment of a hybrid robot to which the methods of the present invention can be successfully applied, and other hybrid robot configurations can also use a single redundant sensor to detect sensor failure. One common preferred configuration of such a different type could have a linear motor as the serial actuator within the link, rather than the angular actuator in the preferred embodiment shown in FIG. 5 .
[0053] It is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art. | An apparatus and method for assuring effective backup for sensor failure in robots, by utilizing a single extra sensor attached between the end actuator and the base. The single extra sensor provides absolute back-up for any single encoder failure that may occur in the system, and statistically significant back-up for any double encoder failure. A single additional sensor effectively provides the robotic system with one redundant information input to the robot control algorithm, which can be used in order to determine whether any of the other control sensors, or even the additional sensor itself, has failed and is delivering an erroneous reading, and hence to warn the operator of the failure. A single additional sensor also provides useful warning of the simultaneous failure of two sensors, since the likelihood that two sensors fail simultaneously in a mode that makes the failures undetectable, can be regarded as statistically insignificant. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 60/740,771, “A Third-Axis Leveling Block for a Bow Sight,” which was filed on Nov. 29, 2005, and which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to sights for archery bows and, more particularly, to devices for leveling sights for archery bows.
BACKGROUND OF THE INVENTION
Archery sights have long been available for use when the bow is held vertically and when the archer and the target are on the same level. As an example of a modern archery sight, please see U.S. Pat. RE 36,266 (“Bow Sight”).
However, these conditions are not always met in the field. First, while archers have long been told to hold their bows in a vertical plane, this orientation is not entirely natural to the human arm. Holding the bow in this vertical position places some rotational stress on the arm. “Canting” the bow, that is, holding it at a slight angle from the vertical plane, feels more natural and reduces the stresses acting on the archer and on the bow thus leading to more accurate shots.
Second, and relatedly, archers in some situations tend to change the cant at which they hold their bow. This change is noticeable when the archer and the target are not on the same level. While hunting in rough terrain, for example, the archer's best (or only) shot often presents itself when the target is either above or below the archer's level. When moving the bow to aim at a target above or below the archer's own position, the archer tends to change the cant of the bow. When using a traditional archery sight, this unconscious change in cant results in shots hitting to the right or left of the target.
For these and other reasons, there is a need for an archery sight that compensates for conditions beyond the idealized conditions of the archery range.
BRIEF SUMMARY OF THE INVENTION
In view of the foregoing, the present invention provides a “third-axis” leveling block for use with an archery sight. The third-axis leveling block holds an archery sighting device (e.g., a scope or a pin sight) as know in the art. The leveling block adjusts the position of the sight in two axes by means of cams. By moving the cams, the archer adjusts the sight to the archer's natural cant and helps the archer to maintain a consistent cant when shooting at targets at any elevation, above, below, or on the same level as the archer.
In some embodiments, the leveling block attaches to an elevation block (possibly by a dovetail connector) of a traditional bow-sight structure. The leveling block in turn holds a traditional sighting device. The leveling block includes two cams to allow adjustments on two generally perpendicular axes. One of the cams adjusts the sighting device to the archer's preferred cant. The other cam adjusts the angle of the sighting device with respect to the bow to keep the archer's cant consistent when the bow is raised or lowered.
In some embodiments, part of the leveling block is made of one piece with the elevation block. In some embodiments, an additional cam (or two additional cams) is (are) added on an axis (axes) parallel to one (both) of the first two cams to allow linear adjustments of the sight.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
FIG. 1 is a perspective view of a typical archery bow equipped with a bow sight;
FIGS. 2 a and 2 b are perspective views of a bow sight incorporating a third-axis leveling block according to the present invention;
FIG. 3 is an exploded assembly view of a third-axis leveling block;
FIGS. 4 a , 4 b , and 4 c are views of a cam usable with a third-axis leveling block;
FIGS. 5 a , 5 b , and 5 c are views showing the effects on a bow sight of a first cam adjustment of a third-axis leveling block; and
FIGS. 6 a , 6 b , and 6 c are views showing the effects on a bow sight of a second cam adjustment of a third-axis leveling block.
DETAILED DESCRIPTION OF THE INVENTION
Turning to the drawings, wherein like reference numerals refer to like elements, the present invention is illustrated as being implemented in a suitable environment. The following description is based on embodiments of the invention and should not be taken as limiting the invention with regard to alternative embodiments that are not explicitly described herein.
A third-axis leveling block according to the present invention can be incorporated into the archery bow arrangement 100 shown in FIG. 1 . Releasably attached to an archery bow 102 and extending outwardly from the archery bow 102 in the general direction of a target, is an elongated support bar 104 . Attached to the end of the elongated support bar 104 is a sighting frame 106 which often takes the form of a vertical C-shaped yoke. The sighting frame 106 can support various adjustment mechanisms, including the third-axis leveling block of the present invention (see FIGS. 2 a and 2 b ), that vary the spatial relationship between the archery bow 102 and the bow-sighting device 108 . Generally, an archer uses these adjustment mechanisms to compensate for various conditions, such as a distance from the archer to the target, wind, elevation of the target relative to the archer, and the archer's natural cant of the bow. For details of a possible archery bow arrangement 100 , please see U.S. Pat. RE 36,266 (“Bow Sight”), which is incorporated herein by reference in its entirety. While the archery bow arrangement 100 shown in FIG. 1 is quite sophisticated, other arrangements are known in the art, and the present invention is not limited to any specific structural context.
FIGS. 2 a and 2 b are different views of a complete archery sight mechanism 200 that incorporates a third-axis leveling block according to the present invention. An attachment mechanism 202 releasably attaches the elongated support bar 104 to the archery bow 102 . (For clarity's sake, the archery bow 102 itself is not shown in these figures.) In the archery sight mechanism 200 shown in FIGS. 2 a and 2 b , the sighting frame 106 attached to the end of the elongated support bar 104 holds a rotatable lead screw 204 . The lead screw 204 holds an elevation block 206 (more easily seen in FIG. 2 b ). When either elevation adjustment knob 208 , located at either end of the lead screw 204 , is turned, the elevation block 206 is raised or lowered to adjust for a distance from the archer to a target. U.S. Pat. RE 36,266 presents the details of one possible elevation block arrangement.
In some embodiments, the elevation block 206 supports a windage block 210 ( FIGS. 2 b ) on a rotatable lead screw (not shown). When the windage adjustment knob 212 is turned, the rotatable lead screw turns, and the windage block 210 moves horizontally, perpendicular to the possible movement of the elevation block 206 . The archer uses the windage block 210 to adjust for prevailing wind conditions. U.S. Pat. RE 36,266 presents the details of one possible windage block arrangement.
In the arrangement of FIGS. 2 a and 2 b , the windage block 210 supports a third-axis leveling block 214 according to the present invention. In one embodiment, the third-axis leveling block 214 includes two adjustment cams and, for each adjustment cam, a pivot. FIG. 2 a shows a first adjust cam 216 and its pivot 218 , while FIG. 2 b shows a second adjustment cam 220 and its pivot 222 . The structure of a possible embodiment of the third-axis leveling block 214 and its attachment mechanisms are shown in greater detail in FIGS. 3 , 4 a , 4 b , and 4 c.
The third-axis leveling block 214 of FIGS. 2 a and 2 b clamps a tube 224 ( FIG. 2 a ) that holds a rod 226 of a bow-sighting device 108 . Preferably, the tube 224 has a hexagonal outer cross section to prevent it from rotating within the clamps of the third-axis leveling block 214 .
FIG. 3 shows an exploded assembly of an embodiment of the third-axis leveling block 214 . In some embodiments, a mounting block 300 of the third-axis leveling block 214 includes a V-shaped notch 302 . This notch 302 forms a half-dovetail connector that attaches to a complementary half-dovetail connector in the windage block 210 (see FIG. 2 b ). The two half-dovetail connectors are wedged tightly together when a screw (not shown) is tightened. This type of connector, described in U.S. Pat. RE 36,266, is preferred because it allows the mounting block 300 of the third-axis leveling block 214 to be tightly and precisely clamped to the windage block 210 via a single screw without putting excessive strain on that screw. In other embodiments, the mounting block 300 of the third-axis leveling block 214 is formed in one piece with the windage block 210 . In that case, a dovetail connector is preferred to connect the third-axis leveling block 214 /windage block 210 to the elevation block 206 .
Attached to the mounting block 300 is a top-hat block 304 . (A possible mechanism for connecting these two pieces is discussed below.) A clamp assembly 306 , shown in FIG. 3 as consisting of two clamps, is in turn attached to the top-hat block 304 . (The present invention is not limited to the details of the specific clamp assembly 306 as shown in FIG. 3 .) The clamp assembly 306 clamps the tube 224 (discussed above with reference to FIG. 2 a ) which in its turn holds a rod of a bow-sighting device 108 (not shown in FIG. 3 ).
The top-hat block 304 is mounted in such a manner that it can pivot relative to the mounting block 300 . The first pivot 218 is shown in FIG. 3 as a screw that passes through a hole in the top-hat block 304 and screws into a first threaded hole in the mounting block 300 . In some embodiments, the first pivot 218 includes a friction-reducing element (such as a Teflon washer). A second screw 308 passes through an elongated hole in the top-hat block 304 , passes through a hole in the first cam 216 , and screws into a second threaded hole in the mounting block 300 . Again, a friction-reducing element 310 can be used. The first cam 216 includes a circular boss (shown in FIGS. 4 a , 4 b , and 4 c ) that fits into a countersunk portion of the second hole in the mounting block 300 . When the first cam 216 is rotated about that boss as it sits in the countersunk portion of the second hole in the mounting block 300 , the first cam 216 pushes on a countersunk area on the top-hat block 304 which causes the top-hat block 304 to pivot around the first pivot screw 218 . The elongated hole in the top-hat block 304 allows the top-hat block 304 to move relative to the second screw 308 and also limits the amount of such movement.
In some embodiments, the clamp assembly 306 is pivotably mounted to the top-hat block 304 in a manner similar to the mounting of the top-hat block 304 to the mounting block 300 . In the embodiment of FIG. 3 , the second pivot 222 is a screw that passes through a hole in the top-hat block 304 and screws into a first threaded hole in the clamp assembly 306 . A second screw 312 passes through an elongated hole in the top-hat block 304 , passes through a hole in the second cam 220 , and screws into a second threaded hole in the clamp assembly 306 . The second cam 220 includes a circular boss (shown in FIGS. 4 a , 4 b , and 4 c ) that fits into a countersunk portion of the second hole in the clamp assembly 306 . When the second cam 220 is rotated about that boss as it sits in the countersunk portion of the second hole in the clamp assembly 306 , the second cam 220 pushes on a countersunk area on the top-hat block 304 which causes the clamp assembly 306 to pivot around the second pivot screw 222 . The elongated hole in the top-hat block 304 allows the clamp assembly 306 to move relative to the screw 312 and also limits the amount of such movement.
In a preferred embodiment, the axes of the pivot screws 218 and 222 are perpendicular to one another. This allows the bow-sighting device 108 (shown in FIGS. 2 a and 2 b ) to be pivoted independently on two axes with respect to the mounting block 300 .
In an embodiment not shown in FIG. 3 , two additional cams are added that pivot around the screws 218 and 222 . This arrangement allows the top-hat block 304 to be linearly shifted with respect to the mounting block 300 by simultaneously shifting two parallel cams, the cam 216 around the screw 308 and the new cam around the screw 218 . In this arrangement, if one of a pair of parallel cams is held in place, then the other cam in the pair serves to pivot the top-hat block 304 as described above in the two-cam embodiment. Similarly, the cams 220 around the screw 312 and the new cam around the screw 222 allow the clamp assembly 306 to be moved linearly with respect to the top-hat block 304 .
FIGS. 4 a , 4 b , and 4 c are different views of a cam 216 , 220 that can be used with the third-axis leveling block 214 . The circular boss 400 that fits into the countersunk portions of the holes in the mounting block 300 and in the clamp assembly 306 is clearly shown in all three figures. The dimensions are given in inches and are appropriate for one embodiment. Other embodiments may require other dimensions. The diameter of the hole through the cam 216 , 220 should be large enough that the cam 216 , 220 does not bind on the screw 308 , 312 that passes through it. The offset of the hole to the center of the cam surface (0.62 inches in FIG. 4 b ) and the outer diameter of the cam surface (0.265 inches in FIG. 4 b ) determine how much movement is caused when the cam 216 , 220 pivots. To ease the manufacture of the third-axis leveling block 214 , it is preferred that the two cams 216 , 220 are identical.
FIGS. 5 a , 5 b , and 5 c show how pivoting the first cam 216 adjusts the position of the bow-sighting device 108 . In FIG. 5 a , the first cam 216 is centered, and the bow-sighting device 108 is held horizontal. In FIG. 5 b , the first cam 216 is rotated counterclockwise from the center position which lifts the bow-sighting device 108 relative to the archery bow 102 (not shown), while in FIG. 5 c , the first cam 216 is rotated clockwise from the center position which lowers the bow-sighting device 108 . This adjustment allows the archer to keep the rod 226 of the bow-sighting device 108 parallel to the ground and the sighting spot 500 of the bow-sighting device 108 directly above the future flight path of an arrow even though the archery bow 102 is held at a cant. By consulting the level 502 , the archer can maintain a consistent cant when pointing the archery bow 102 uphill or downhill.
FIGS. 6 a , 6 b , and 6 c show how pivoting the second cam 220 adjusts the position of the bow-sighting device 108 . In FIG. 6 a , the bow-sighting device 108 is at a median distance from the archer. In FIG. 6 b , the second cam 220 is rotated counterclockwise which pivots the bow-sighting device 108 away from the archer, while in FIG. 6 c , the second cam 220 is rotated clockwise which pulls the bow-sighting device 108 toward the archer. This adjustment keeps the bow-sighting device 108 aligned with the flight of an arrow even as the bow 102 twists under full draw.
In view of the many possible embodiments to which the principles of the present invention may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the invention. Those of skill in the art will recognize that some implementation details, such as the attachments to the windage block and to the bow-sighting device, are determined by specific situations. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof. | The present invention provides a “third-axis” leveling block for use with an archery sight. The third-axis leveling block holds an archery sighting device (e.g., a scope or a pin sight) as know in the art. The leveling block adjusts the position of the sight in two axes by means of cams. One of the cams adjusts the sighting device to the archer's preferred cant. The other cam adjusts the angle of the sighting device with respect to the bow to keep the archer's cant consistent when the bow is raised or lowered for shooting at targets at any elevation, above, below, or on the same level as the archer. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my copending application Ser. No. 404,938 filed Aug. 3, 1982, now abandoned.
This invention relates to a flash suppressor for firearms. More particularly, this invention relates to a flash suppressor for use by attachment to the muzzle end of a variety of rifles of different calibers, as well as larger weapons including cannons and the like and pistols as well.
BACKGROUND AND OBJECTS OF THE INVENTION
In the prior art, many different types of devices have been proposed for attachment to the end of the barrels of firearms for accomplishing various purposes. Most notably, such attachments have been for the purpose of silencing the noise produced by the firing of the gun or for reducing the recoil of the gun. Some such attachments have been proposed for stabilizing the flight of the projectile. A few such attachments have been proposed for reducing the flash emitted from the end of the barrel when the gun is fired.
For example, U.S. Pat. Nos. 587,802 to Durnford; 323,303 to Fosberry; and 37,193 to Alsop disclose attachments for shotgun type barrels for stabilizing a signal projectile with such guns.
So-called silencers are well known, and usually comprise an attachment having a series of baffles which are designed to reduce the noise.
U.S. Pat. No. 32,685 to DeBrame discloses a gun barrel design which utilizes a so-called "skeleton barrel" whereby the barrel has a number of longitudinally extending slots formed therein. The slots are either straight, in the case of unrifled barrels, or spiraled in the case of a rifled barrel. The purpose of these slots is to reduce the amount of metal which can contact the projectile in order to reduce the friction on the projectile and thereby improve the ballistic characteristics of the projectile, namely the force and distance of the projectile.
However, these prior art patents are primarily intended for use with firearms using black powder, rather than modern smokeless powder, and the difference in the type of powder used is significant, and well known. Black powder produces an "explosion" and produces a high amount of smoke upon firing the gun, and additionally leaves a significant residue on the barrel of the gun, and has a much lower pressure exerted on the projectile, resulting in quite different ballistic characteristics.
Moreover, due to the explosive "burn" of black powder, the gas pressure and the projectile velocity reach a maximum at a point ahead of the muzzle end of the barrel, while the gas pressure which results from smokeless powder produces an increasing velocity of the projectile as it travels through the barrel until it leaves the barrel. As a result, with black powder, the projectile tends to be coasting before it leaves the barrel, and any reduction in friction in the barrel would increase the muzzle velocity, but simply by reducing the drag on the projectile. However, increased barrel lengths produce greater accuracy, and thus there must be a compromise between accuracy and projectile velocity (or force) in the case of black powder firearms.
The increasing velocity of projectiles which are fired from smokeless powder, however, is a result of the controlled burn of the powder resulting in steadily increasing gas pressure (and velocity) until the projectile leaves the gun barrel. Thus, the use of smokeless powder produces both greater velocity and greater accuracy, since longer barrels may be used without sacrificing accuracy for force.
However, as a result of this controlled burning, there usually exists some powder still burning at the point when the projectile leaves the barrel, and the burning of this powder outside the muzzle end of the barrel produces a flash of light shortly beyond the end of the barrel. This flash of light is undesirable in some circumstances, and gives rise to the need for a flash suppressor or flash hider for use in firearms using modern, smokeless powder.
A flash suppressor is, however, by its very nature rather different from a noise suppressor or silencer. An attachment for reducing noise is similar in nature to a muffler which has baffles and chambers to reduce the noise of gasses passing through the device. When such noise suppressors are used on rifles, however, they greatly reduce the velocity of the bullet emerging from the barrel and also the accuracy of the gun to which they are attached. Thus such silencers are unsuited for use on rifles and the like for longer range shooting where accuracy becomes more critical.
Flash suppressors, however, must be capable of use on rifles used for long range shooting without hampering the accuracy of the gun.
Accordingly, a primary object of the present invention is to provide an improved flash suppressor for use with rifled gun barrels.
Another object of the present invention is to provide a flash hider for gun barrels which does not deleteriously affect the accuracy of the firearm.
A further object of this invention is to provide a flash suppressor capable of reducing the visibility of the muzzle flash of a firearm on the order of 40-50% and more over conventional flash suppressors in use.
Still another object of the invention is to provide a flash suppressor which actually improves the ballistic characteristics of the projectile after it leaves the muzzle end of the gun while still providing the greatly enhanced suppression of the muzzle flash.
Yet a further object of the present invention is to provide a flash suppressor which may be used with a variety of different calibers of firearms with similarly improved results.
Yet another object of this invention is to provide an improved flash suppressor which improves the muzzle velocity and the accuracy of the gun while still significantly reducing the muzzle flash.
These and other objects of the invention will become apparent when considered in light of the following specification and claims, when taken together with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of one embodiment of a flash suppressor according to the present invention;
FIG. 2 is a longitudinal cross sectional view along lines 2--2 of FIG. 1 and viewed in the direction of the arrows;
FIG. 3 is a side elevation view of another embodiment of a flash suppressor of the present invention;
FIG. 4 is a longitudinal cross sectional view along lines 4--4 of FIG. 3 and viewed in the direction of the arrows;
FIG. 5 is a sectional view taken along lines V--V of FIG. 3 and viewed in the direction of the arrows;
FIG. 6 is a sectional view taken along lines VI--VI of FIG. 4 and viewed in the direction of the arrows;
FIG. 7 is a longitudinal sectional view of another embodiment of a flash suppressor according to the present invention; and
FIG. 8 is a sectional view taken along lines 8--8 of FIG. 7 and viewed in the direction of the arrows.
FIG. 9 is an enlarged cross sectional schematic of a gun barrel.
BRIEF DESCRIPTION OF THE INVENTION
The flash suppressor of the present invention is adapted for attachment to a conventional rifled gun barrel of standard calibers. Such gun barrels are often provided on their muzzle ends with threaded ends for attachment of flash suppressors, silencers, sights, and the like, and the suppresors of this invention are provided with a correspondingly threaded portion to facilitate such attachment.
The flash suppressor comprises a cylindrical body having a first portion immediately adjacent the end of the rifled barrel, and a second portion extending from the first portion to the discharge end of the suppressor.
The first portion consists of a length of a smooth bore (i.e., not rifled) of a specified constant internal diameter. The diameter of the smooth bore portion is a function of the caliber of the gun, as will be described shortly. The second portion is of a greater internal diameter than the first portion, and is also provided with a plurality of longitudinal extending, radially directed vents openings to the outside of the body from the internal bore.
In a conventional rifled barrel, the barrel has a bore diameter of a given dimension, and has rifling grooves formed therein to a depth such that a circle passing through the bottom of the rifling grooves is slightly greater in diameter than the bore diameter. For example, the bore diameter of a .223 caliber rifle barrel is 0.2190 inch, while the depth of the grooves is such that the diameter of a circle passing the bottom of the grooves would be 0.2240 inch. In other words, the grooves have a depth of 0.0025 inch, i.e. one half of the difference between the bore diameter and the groove diameter.
For such a rifle, the bullet has an initial diameter of 0.2240 inch, and thus as the bullet passes through the barrel it is reduced slightly in diameter in the area of the bore and it is elongated slightly as it passes through the barrel.
According to the present invention, the first portion of the suppressor body, i.e. the smooth bore passage, has an internal diameter slightly less than the groove diameter of the rifling grooves, and preferably between that of the bore diameter of the barrel and the groove diameter. The effect of this is to further elongate the bullet and squeeze it down and also to provide a further burn time, and thus greater acceleration time for the bullet.
The second portion of the suppressor body is of an inside diameter significantly greater than the smooth bore (or first) portion so that the bullet can not contact the inside of this second portion. The enlarged inside diameter of this second portion permits an expansion of the gasses, and the vents provided in the second portion of the cylindrical body permit the escape of unburned gasses without ignition thereof or with reduced ignition or "flash."
Preferably the first portion, i.e. the smooth bore portion of the suppressor has a diameter of 0.0006 to 0.0008 inch less than the diameter of a circle passing through the bottom of the rifling grooves, as this has been found to provide the optimum effect and to allow for improved thermal expansion of the bullet. The length of the smooth bore portion of the suppressor body is not particularly critical, and is more a function of the additional length permissible for a given rifle. However, generally it has been found that each one inch length of this first, or smooth bore, portion of the body provides an increase of 25-35 feet per second (fps) in the muzzle velocity, up to the limit of the amount of powder in the cartridge.
In the case of the .223 caliber example above, the optimum length of the smooth bore portion of the suppressor has been found to be 1.687 inch, allowing for a significant increase in the velocity of the bullet, a more complete burn of the powder, and by virtue of the more complete burn of the powder and gasses a reduced possibility for flash at the muzzle end due to ignition of unburned gasses.
The second portion of the body of the suppressor, as indicated above, is provided with a plurality of radially directed, longitudinally extending vents. The vents are formed in a portion of the cylindrical body in which the internal diameter is significantly greater than the internal diameter of the first portion, so that the bullet cannot contact the inside wall of this second portion, while the outside diameter is substantially the same as the outside diameter of the first portion. In the case of the same example of a .223 caliber gun, the inside diameter of the slotted portion of the suppressor would be about one-half inch.
The vents are in the nature of slots cut into the body through the wall thereof. The inside wall of the second portion terminates in an outwardly flared end permitting still further expansion of the gas prior to complete release.
The vents also form a series of longitudinally extending ribs or flutes between the vent openings. In one embodiment, these ribs extend longitudinally a distance greater than the length of the vent opening, and thereby extend toward the gun barrel over a portion of the smooth bore section formed on the inside of the body. In this manner, the ribs may act as fins to dissipate heat from the suppressor body.
The number of vents (and thus the number of fins) is a function of the caliber of the gun upon which the suppressor is to be used, and thus the diameter of the body of the suppressor, since larger caliber guns (having larger diameter barrels) will permit use of more vents (and fins.) Generally speaking, the vent slots and the fins should each have thicknesses of about three-sixteenths inch to about one-eighth inch.
The body of the suppressor may also be provided with means for facilitating the threaded attachment of the body to the barrel, such as flats for engagement by a wrench of blind holes for use with a suitable spanner-type wrench. In addition, means may be provided for securing the suppressor body onto the end of the barrel, such as a pin passing chordally through the threaded portion of the barrel/suppressor junction, or by means of set screws passing radially through the body of the suppressor and engaging the threaded extending portion of the barrel.
The foregoing dimensions are set forth merely by way of example with respect to a particular caliber of gun, and the invention is not limited to this caliber. The principles of the invention are equally applicable to other calibers by following the principles and teachings set forth herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to the embodiment of FIGS. 1 and 2 there is seen a flash suppressor generally designated 10 removed from a gun barrel 12. The barrel 12 is provided with an externally threaded end portion 14.
The flash suppressor 10 comprises a generally cylindrical body 16 having a first portion with an internal smooth bore 18 and a second portion provided with longitudinally extending, radially directed vent slots 20 separated by vanes 22. The inside diameter of the counterbore 24 of the body in the area of the vent slots 20 is significantly greater than the diameter of the smooth bore portion 18, on the order of twice the diameter of the smooth bore portion 18.
The body 16 is provided with an internally threaded portion 26 corresponding to the threaded portion 14 of the barrel 12, in order that the suppressor may be threaded onto the barrel. To facilitate tightening of the suppressor 10, a pair of diametrically opposed flats 28 may be provided on the body 16, so that a wrench may be used to tighten the suppressor on the barrel.
The end of the smooth bore 18, adjacent the threaded portion 26, may be slightly chamfered to facilitate entry of the projectile into the bore 18. Because of the dimensions involved, this chamfering is very slight, and not able to be seen in the drawing.
The external surface of the body 16 may also be provided with a ring 30 for mounting a blank firing device, and a bayonet mounting ring 32 for the addition of suitable attachments such as sighting devices or bayonets in a conventional manner.
The vanes 22 are formed in the body 16 by cutting slots 34 therein in such a manner as to provide the desired number of slots 20 and vanes 22. The slots and the vanes should be of a width on the order of one-eighth inch to three-sixteenths inch, and following this dimension, the number of slots (and vanes) will be determined according to the external diameter of the body 16. For a .223 caliber rifle, eight vents and eight flutes have been found to be the preferred number of slots and flutes.
The bore 24 preferably terminates in an outwardly flared portion 36 at the distal end of the body 16.
As depicted in FIG. 9, a gun barrel 12 has an internal bore A and is provided on its inside surface with a plurality of spirally arranged rifling grooves B. The diameter of the bore A is thus given by "a". The bottoms of the grooves B lie on a circle whose diameter is given by "b". Accordingly, the inside diameter "SB" of the smooth bore 18 of the flash suppressor 10 is thus given by the expression b>SB, and preferably b>SB>a.
In the preferred instance, the diameter of the smooth bore portion 18 of the suppressor would be given by the expressions SB=b-(0.0006 inch to 0.0008 inch) and SB>a.
When these relationships are met, the projectile will be squeezed down in diameter and elongated when it passes into the smooth bore portion 18, and the continued burn of the powder and gasses will result in increased acceleration as the bullet passes through the bore 18.
When the bullet enters the bore 24, it will be free of contact with the barrel or the flash suppressor. When the bullet exits the bore 18, the gasses behind it are free to expand in the area of the counterbore 24 and escape through the vent slots 20. Since the gasses have been allowed to expand, and thus cool slightly, there is less opportunity for the gasses to ignite upon release.
FIGS. 3 through 6 show another slightly different embodiment of the invention. Here, the body 40 also has a threaded internal bore 42 at one end for attachment to a rifled barrel B. The threaded bore 42 leads to a smooth bore portion 44. A pair of radially directed, threaded holes 46 as provided and pass into the bore 42. The holes 46 are adapted to receive set screws which may be tightened against the barrel B in order to secure the flash suppressor on the end of the barrel.
A plurality of blind holes 48 are also provided in the outside surface of the body 40 for engagement by a suitable spanner wrench (not shown) in order to tighten the suppressor onto the barrel B.
As in the previous embodiment, the smooth bore 44 opens into a counterbore 50 of greater diameter. The counterbore area of the suppressor is provided with a plurality of vent openings 52 which are separated by vanes or fins 54.
And its distal end, the counterbore 50 has an outwardly flared end portion 56.
Again, the diameter of the smooth bore portion 44 must be greater than the diameter of the bore of the rifle barrel B, but less than the diameter of a circle passing through the bottom of the rifling grooves, as in the previous embodiment.
FIGS. 7 and 8 show another embodiment of a flash suppressor according to the present invention, again where the body 60 of the suppressor is provided with an internally threaded portion 62 at one end for threaded engagement with the end of a rifle barrel 64. A smooth bore passage 66 extends longitudinally through the body 60 and opens into a counterbore 68 of significantly greater diameter.
The counterbore 68 is provided with a plurality of vent openings 70, and a flared distal end portion 72.
In order to secure the flash suppressor 60 onto the barrel 64, a chordally arranged hole 72 is drilled so as to pass through the junction of the threads on the barrel 64 and on the suppressor 60. A tapered pin 74 may then be driven into the hole 72, thus securing the two parts against rotation such as would disassemble the suppressor and the barrel.
Visual observation of the flash produced by an M16Al rifle of .223 caliber, firing 5.56 mm A071 ball ammunition gives the impression that the flash is much less than that produced by the same rifle with a standard suppressor. To confirm this observation, the muzzle flash was recorded photographically, and the results were analyzed with a densitometer.
The results of the densitometer readings were adjusted such that pure black would register 100 density units (du) and pure white would register 0 du. The following table shows a comparison of the flash obtained from the foregoing rifle using a standard flash suppressor and the improved suppressor according to the present invention.
TABLE______________________________________ Standard Invention Difference______________________________________Actual Muzzle 44 du 88 du 44 duTop Vane 61 95 34Middle Vane 48 95 47Bottom Vane 63 93 30Top Flare NA 94-92 NAMiddle Flare NA 92-90 NABottom Flare NA 94-89 NAMuzzle FlashAverage 86.6 73.2 13.4______________________________________
In density unit measurement, 30 du represents a difference of 50% in density. Thus, the average vane flash reduction produced by the present invention was 38.5 du, or better than a 50% reduction in vane flash. Further, while the muzzle flash appears to have increased, the flash produced by the suppressor of the present invention was reddish in color compared to the yellow flash of the standard suppressor, and thus is far less visible to the eye. In addition, the flash of the rifle using the suppressor according to the present invention was 60% smaller than the flash emitted by the standard suppressor.
The overall reduction in the flash of the suppressor of this invention compared to the prior art was 41-46%.
Thus, the flash suppressor of this invention is highly effective in reducing vane and muzzle flash.
Other tests have been conducted to compare the velocity and accuracy of ammunition fired using both a prior art type flash suppressor and a suppressor according to the present invention. One such test used a standard M-16 top receiver, .223 caliber rifle, with ammunition loaded with M-193 Winchester bullets and Winchester ball powder at 55 grains.
The barrel of the rifle had a 1 in 12" twist and open sights. The rifle was fired at a target at 50' distance, with instrument distances of 5' and 10'.
Using the prior art flash suppressor, a 10 shot test showed recorded velocities ranging from 3,053 feet per second (fps) to 3,196 fps, with an average velocity of 3,109 fps and a standard deviation of 46. The shots produced a group of 21/4 inch by 13/4 inch.
With the flash suppressor according to FIGS. 1 and 2 of this application, using the same rifle and the same ammunition, fired by the same tester and the same test instrument, the measured velocities for a 10 shot test ranged from a low of 3,153 fps to a high of 3,203 fps and an average of 3,173 with a standard deviation of 14. The 10 shot group measured 11/4 inch by 1 inch.
A similar test was conducted using a .308 caliber Winchester rifle. With the prior art flash suppressor, the bullet velocity ranged from a low of 2,742 fps to a high of 2,811 fps and an average velocity of 2778 fps and a standard deviation of 34. The ten shots produced a group measuring 33/4 inch by 31/4 inch.
After switching to a flash suppressor according to the present invention, the 10 shots ranged in velocity from a low of 2,868 fps to a high of 2,885 fps with an average of 2,878 fps and a standard deviation of 7. The ten shots were in a group measuring 21/2 inch by 2 inch.
Thus, the flash suppressor according to the present invention produced markedly superior results in comparison to the prior art flash suppressor.
While this invention has been described as having certain preferred features and embodiments, it will be apparent that it is capable of still further modification, and this application is intended to cover all modifications, variations and adaptations of the invention which fall within the spirit of the invention and the scope of the appended claims. | A flash suppressor for use on a rifled barrel of a firearm comprising a generally tubular body member having a first portion adapted to receive a projectile from the barrel and a second portion adapted to receive a projectile from the first portion, the first portion having a longitudinal smoothbore passage therethrough, through which a projectile discharged from the barrel passes, the barrel and the first and second portions being coaxial, and the smoothbore passage having a diameter less than the diameter of a circle passing through the bottom of the rifling grooves in the barrel, the second portion having an inside diameter significantly greater than the diameter of the smoothbore passage, and a plurality of radially directed vent openings formed in the second portion of the body member. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Serial No. 60/194,568 filed Apr. 3, 2000. The disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to an electromagnetically or hydraulic actuated pulse driven two position ratchet mechanism for valve deactivation in push rod and overhead camshaft internal combustion engines. This pulse system can be adapted to a push rod configuration, or at a rocker location of an overhead camshaft valve drive. For improved fuel economy strategic cylinders would be deactivated by inducing a break in the valve drive linkage using a time sensitive switching device activated by an energy conserving pulse versus the continuous power on versions.
DESCRIPTION OF RELATED ART
[0003] Traditionally, valve deactivation devices are complex designs employing a remote located solenoid using a drive linkage which is held to the on position by a continuous energy draw to a solenoid coil, or continuous hydraulic pressure. Valve deactivation systems (VDS) date back to the early 1970s. The first successful system was a latchable fulcrum for pushrod rocker arms on Cadillac V8 engines in 1981. Further present day valve deactivation system examples are those of INA Motor Enelment uses a 3 lobe camshaft, dual bucket configuration for overhead camshaft engines wherein a high lift/no lift event is achieved by driving the outer bucket with the higher profile peripheral camshaft lobes for high lift, and driving the central camshaft lobe and bucket for no lift. This system employs a sliding hydraulic operating pin, which switches to connect outer bucket to inner bucket to generate, timed lift event. Another INA design uses a two-piece valve rocker where the primary rocker section driven by the camshaft is connected or disconnected to a secondary rocker activating the valve by a sliding pin. It should be appreciated that all valve deactivation systems need a power supply, and a driven switching engagement element such as a pin, which is very critical to operation. The reason for this preciseness is you only have the rest time, or camshaft base circle time when the valvetrain rockers and pushrods are not in motion for insertion of a locking pin or switching element. It also should be noted that the switching sequence time decreases, as engine RPM becomes higher. Therefore, it is an advantage to use a time compatible geometry for switching element.
SUMMARY OF THE INVENTION
[0004] The present invention provides a compact concentrically located solenoid drawing a short energy pulse to drive a ratcheted geometric switching key to join or detach adjacent moving valvetrain elements. A significant feature of this design is its fast, direct solenoid reaction time, and specialized rotative locking key which moves at the same velocity as the retaining member it is locked to for valve deactivation.
[0005] It is therefore a primary object of this invention to provide a specialized locking key which, unlike a pin or latch, when driven will provide superior performance within camshaft base circle diameter time window.
[0006] It is another object of this invention to locate the driving armature close to the locking key to lower the mass of the connecting members needed to switch the locking key for faster operation.
[0007] It is yet another object of this invention to design a solenoid concentrically to delete remote connecting members, simplify design, and lower drive members for fast reaction time.
[0008] It is still another object of this invention to drive the locking key to an engaged position with one energy pulse.
[0009] It is yet another object of this invention to combine the solenoid locking system and tappet in one compact assembly for push rod application.
[0010] It is a further object of this invention to be adaptable for location high in a cylinder head for easy service.
[0011] It is still a further object of this invention to adapt the solenoid and locking key assembly to a primary and secondary rocker for valve deactivation on overhead camshaft engines.
[0012] To achieve the foregoing objects, the present invention provides an electromagnetically pulse driven two-position specialized ratchet mechanism for valve deactivation. One advantage of the present invention is a low mass special key for faster response is used operating in camshaft base circle diameter time window.
[0013] Another advantage of the present invention is that the driving armature can be located very close to the switching key for fast activation.
[0014] A further advantage of the present invention is that the solenoid is designed concentrically creating a compact unit deleting the need for remote connecting elements.
[0015] A further advantage of the present invention is that the locking key is driven to the engaged position by one pulse, thus conserving the energy needed to activate versus continuously applied versions.
[0016] Still another advantage of the present invention is that the activation unit can be adapted to both push rod and overhead camshaft engines.
[0017] Yet still another advantage of the present invention is that the electro solenoid system does not contend with the low RPM oil pressure, and oil pump energy draw of hydraulic systems.
[0018] Another advantage of the present invention is that the locking key has more latitude in build tolerancing.
[0019] Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood after reading the subsequent description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0021] [0021]FIG. 1 is a cross section of a pulse drive valve deactivator, according to the principles of the present invention;
[0022] [0022]FIG. 2 is a cross section of the pulse drive valve deactivator showing the solenoid armature in a locking mode;
[0023] [0023]FIG. 3 is a cross section of the pulse drive valve deactivator showing the energy flow in the locked mode;
[0024] [0024]FIG. 4 is a cross section of the pulse drive deactivator showing the tappet in a high lift position working in the unlocked mode;
[0025] [0025]FIG. 5 is a cut-away perspective view illustrating the locking key in unlocked mode;
[0026] [0026]FIG. 6 is a cut-away perspective view illustrating the locking key in locked mode; and
[0027] [0027]FIG. 7 is a side view of the pulse drive valve deactivator adapted to be used with a roller finger follower type overhead camshaft system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0029] With reference to FIG. 1, the pulse drive valve deactivator 1 of the present invention is shown as a compact unit mounting over tappet 2 . The pulse drive valve deactivator can be utilized for present production engines or integrated into a tappet for new engine applications. The valve deactivator 1 is illustrated to be mounted in position by fastener 3 abutting the key drive retainer 4 adjacent the tappet 2 at surface 5 . As the camshaft (not shown) rotates, tappet 2 moves in the direction of arrow “ 6 ” driving the key drive retainer 4 which compresses lost motion spring 7 against surface 8 of push rod retaining socket 9 .
[0030] Push rod retaining socket 9 is held immobile by push rod 13 . The valve spring (not shown) acting upon the push rod 13 has a higher spring constant than the spring constant of lost motion spring 7 . As key drive retainer 4 moves in an unlocked mode, channel 10 slides along lugs 11 of stationary positioned locking key 12 . Locking key 12 is loaded against key driver 14 by spring 15 and pivot ball 15 A which are received in a central bore 9 A of the push rod retaining socket 9 . Key driver 14 is joined to armature 16 at opening 17 which receives a head portion 14 A of the key driver 14 . Armature 16 is held against a stop 18 extending from an internal wall 19 A of solenoid frame 19 by a wave spring 20 .
[0031] Key drive retainer 4 employs fingered projections 21 working through windows 22 provided in the armature 16 for connection to the tappet 2 . It should be appreciated that in an unlocked mode only tappet 2 and key drive retainer 4 compressing lost motion spring 7 against surface 8 of push rod retaining socket 9 are moving as the camshaft (not shown) turns. Tappet 2 needs a diameter lift distance “ 23 ” (best shown in FIG. 1) to work in. Referring to FIG. 2, push rod 13 is activated during the time cycle at the beginning of the compression stroke, and the end of the power stroke when the valves are closed, and the valvetrain is at rest. During this period, coil 24 is energized from a power supply creating a magnetic field attracting the armature 16 toward the core 25 at surface 26 . Movement of the armature 16 drives the key driver 14 , thus propelling the locking key 12 along the channel 10 and thereby compressing spring 15 (shown compressed in FIG. 2). As the locking key 12 is propelled toward the surface 27 of push rod retaining socket 9 , locking key 12 is joined to key drive retainer 4 at the connecting juncture position 28 . The locking key 12 drives the push rod retaining socket 9 driving the push rod 13 activating the valve (not shown). It should be noted that when push rod 13 is driven in the direction of arrow “ 6 ,” the locking key 12 is compressed between surface 27 and connecting juncture 28 holding that locked position. When the valve spring thrusts the rocker (not shown) and push rod 13 in the direction of arrow “ 29 ,” the inertia of the locking key 12 and spring 15 are working in conjunction to keep the locking key 12 at a connection juncture 28 until the camshaft base circle time zone is reached wherein only spring 15 keeps locking key 12 seated.
[0032] During the camshaft base circle time period the solenoid is energized driving the locking key 12 to compress spring 15 and index the locking key 12 to the unlocked mode.
[0033] It should be appreciated that during this event, the locking key 12 moves rotatively at the same velocity as key drive retainer 4 .
[0034] Referring to FIG. 3, the pulse drive valve deactivator 1 is shown functioning in a locked mode driving push rod 13 . Wave spring 20 returns the armature 16 to a rest position against stop 18 of the solenoid frame 19 . Tappet 2 is shown in a high lift position driving the key drive retainer 4 which is joined to the locking key 12 at connecting juncture 28 thereby activating push rod retaining socket 9 . As the push rod retaining socket 9 is activated, push rod 13 is moved. (Energy flow is illustrated by arrow “ 39 .”) It should be appreciated that during the locked mode, the lost motion spring 7 is not compressed and the key drive retainer 4 slides along the key driver 14 along channel 10 . Referring to FIG. 4, the pulse drive valve deactivator 1 is shown functioning in an unlocked mode with tappet 2 in a high lift position driving the key drive retainer 4 and compressing lost motion spring 7 . It should be noted that the only parts in motion are the tappet 2 and key drive retainer 4 moving along fixed locking key 12 and key driver 14 at channel 10 .
[0035] [0035]FIG. 5 provides a detailed illustration of the locking event. Locking key 12 is shown in an unloaded mode wherein key drive retainer 4 slides along locking key 12 along grooves 30 . When the system is to be locked, the armature 16 moves the driver 14 in an upward direction which drives the locking key 12 along grooves 30 . As spring 15 is compressed, torsional energy is stored promoting the locking key 12 to rotate because of the interface of slope 31 and space 32 . This misalignment exists until locking key 12 is high enough wherein point 33 of locking key 12 is even with point “ 34 ” of key retainer 4 . At this time, the locking key 12 is free of groove 30 and will start to index in the direction of arrow “ 35 ” because of the spring load, slope 31 , and filling misalignment space 32 will excite locking key 12 to rotate to the locked position as shown in FIG. 6. It should be noted that the energy pulse applied by the armature 16 could also be supplied by other pulse energy activating devices including hydraulic, pneumatic, or mechanical actuator systems that can replace or be substituted for the armature and coil system. It is important to note that because of the torsional energy stored by spring 15 , it is only an energy pulse that is required to engage the locking key.
[0036] Referring to FIG. 6, the locking event is a two-stage event because the timed solenoid energy pulse drives the locking key 12 out of groove 30 to begin rotation but energized spring 15 completes the locking/seating event, as the solenoid charge decays, forcing the locking key 12 to continue to rotate as point “ 39 ” of locking key 12 aligns with point “ 36 ” of the key drive retainer 4 completing rotation of the locking key 12 to a locked seated position as shown at position 37 and 38 . It should be appreciated that when in the locked mode, spring 15 always loads the locking key 12 to the locked position 37 and 38 during camshaft base circle time duration.
[0037] To unlock the system, armature 16 strokes in the direction of arrow “ 6 ” driving the key driver 14 into the locking key 12 and compressing spring 15 . At this time, misalignment at slope 31 and space 32 lifts and rotates the locking key 12 in the direction of arrow “ 35 ” over positions 37 and 38 propelling the locking key 12 down grooves 30 to the unlocked mode as shown in FIG. 5.
[0038] [0038]FIG. 7 is a side view showing a roller finger follower (or end pivot rocker arm), pulse drive deactivator combination lash adjuster adapted to an overhead camshaft engine. The pulse drive deactivator 1 (shown in phantom) positions a lash adjuster 40 at a location 41 for a deactivated mode where rocker arm 42 rotates and compresses lost motion spring element 43 . When valve 44 is to be activated, the pulse drive deactivator 1 cycles an energy pulse activating the locking key 12 moving the lash adjuster 40 to the valve drive location 45 wherein rocker arm 42 rotates to migrate valve 44 compressing valve spring 46 (shown in phantom).
[0039] The present invention has been described by text and images conveying a combination of conceptual ideas based on primary designs. It is to be understood that many evolutionary modifications and variations of the present invention are possible in light of the above description. | A valve deactivator is provided that is capable of being activated and deactivated by a pulse energy input. The valve deactivator includes an input member and an output member which are movable relative to one another in the deactivated mode and which are engaged for simultaneous movement in an activated mode. A coil and armature, or other pulse energy input means, are provided to engage and disengage a locking system to activate and deactivate the valve actuator. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
The present application claims priority to Korean Patent Application No. 10-2015-0028346, filed Feb. 27, 2015, the entire contents of which is incorporated herein for all purposes by this reference.
BACKGROUND OF THE INVENTION
1 . Field of the Invention
The present invention generally relates to a height-adjustable table. More particularly, the present invention relates to a height-adjustable table configured such that a height adjustment member rotates in response to an operation of an actuation unit, thereby being released from a locked state, and when an upper plate of the table is vertically lifted to a desired level, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes the optimal space utility and a simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing user convenience.
2 . Description of the Related Art
Generally, a table is manufactured in various sizes and shapes according to its intended use. When manufacturing a table for children, the table is small and light, but when manufacturing a table for a home or an office, the table requires durable and robust for its use, and thus it is big and heavy.
The table is typically made up of an upper plate and a plurality of support legs, and when used, the table is used with the support legs spread, but when unused, the table is stored with the support legs folded.
However, the conventional table has a problem in that when the support legs of the table are spread from the upper plate, the table is fixed to a single predetermined height for use, and it is impossible to adjust the height of the upper plate, thus the utility of the table is low.
To address the issue, a table constructed in a folding manner to be conveniently used is on the market. When the upper plate of the folding table is lifted, the folded upper plate is lifted up diagonally while describing a parabola. Accordingly, the folding table has a problem in that it requires a larger space for use, and thus space utility is low.
In recent years, to solve the problem, a table height-adjustment device has been proposed as disclosed in Korean Patent No. 10-0330661.
The invention of the related art includes: first longitudinal guide holes provided at two opposite sides of an upper plate of a table; second longitudinal guide holes provided at sides of supporting plates securely placed inside supporting poles; folding links movably combined with the first and second longitudinal guide holes; a moving unit connected with lower pins to stretch the folding links; a threaded shaft moving the moving unit forward and backward within the range of the second longitudinal guide holes; and rotating means to rotate the threaded shaft. Accordingly, the table of the related art can adjust the height of the table unlike the existing tables, and thus it can be used conveniently and comfortably.
However, in the invention of the related art, if a decelerating motor or a handle is rotated to adjust the height of the table, the threaded shaft rotates to close or open the folding links, thereby lifting or lowering the upper plate. Accordingly, since the inner structure of the table of the related art is complex, the table is difficult to fabricate, thereby increasing manufacturing cost and often causing malfunctions.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.
3 . Documents of Related Art
(Patent Document 1) Korean Patent No. 10-0330661.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and the present invention is intended to propose a height-adjustable table configured in such a manner that a height adjustment member rotates in response to the operation of an actuation unit, thereby being released from a locked state, and when an upper plate is vertically lifted to a desired height, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes the optimal space utility and simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing user convenience.
In order to achieve the above object, according to one aspect of the present invention, there is provided a height-adjustable table including:
an upper plate;
a leg unit mounted to a lower surface of the upper plate and having a lifting unit provided in such a manner that when an actuation unit is operated, the lifting unit is lifted or lowered while a locking protrusion of the lifting unit is locked in one of a plurality of height adjustment holes of a height adjustment member;
the actuation unit including:
an actuation lever rotatably combined with a fixed mount to rotate based on a shaft pin, the fixed mount being fixed to the lower surface of the upper plate; and a pressure member pressurizing a height adjustment unit while the actuation lever is operated, wherein when the actuation lever is operated, the locking protrusion of the leg unit is released from or locked in one of the height adjustment holes of the height adjustment member while the pressure member applies a pressure to the height adjustment member or removes the pressure therefrom; and
the height adjustment unit provided in such a manner that while the actuation unit is operated, the locking protrusion is released from or locked in one of the height adjustment holes to progressively adjust the height of the leg unit while the height adjustment member rotates based on a shaft thereof, the height adjustment unit being combined with an inner side of an upper bracket of the leg unit.
The present invention has an advantage in that the height adjustment member rotates in response to the operation of the actuation unit of the present invention, thereby being released from a locked state, and when the upper plate is vertically lifted to a desired height, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Accordingly, the present invention realizes optimal space utility and a simple inner structure of the height-adjustable table, thereby reducing manufacturing cost and increasing users' convenience.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a front sectional view of the present invention;
FIG. 2 is a side sectional view of the present invention;
FIGS. 3 to 7 are views showing the operation of the present invention; and
FIGS. 8 and 9 are views showing the use of a table put in a table receiving space.
DETAILED DESCRIPTION OF THE INVENTION
Hereinbelow, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. Throughout the drawings, the same reference numerals will refer to the same or like parts.
The height-adjustable table 100 of the present invention includes: an upper plate 110 ; a leg unit 120 mounted to a lower surface of the upper plate 110 and having a lifting unit 122 provided in such a manner that when an actuation unit 130 is operated, the lifting unit 122 is lifted or lowered while a locking protrusion 122 b ′ of the lifting unit 122 is engaged with one of a plurality of height adjustment holes 142 c of a height adjustment member 142 ; the actuation unit 130 including: an actuation lever 131 rotatably combined with a fixed mount 131 a to rotate based on a shaft pin 131 b , the fixed mount 131 a being fixed to the lower surface of the upper plate 110 ; and a pressure member 132 pressurizing a height adjustment unit 140 while the actuation lever 131 is operated, wherein when the actuation lever 131 is operated, the locking protrusion 122 b ′ of the leg unit 120 is released from or engaged with one of the height adjustment holes 142 c of the height adjustment member 142 while the pressure member 132 applies a pressure to the height adjustment member 142 or removes the pressure therefrom; and the height adjustment unit 140 provided in such a manner that while the actuation unit 130 is operated, the locking protrusion 122 b ′ is released from or locked in one of the height adjustment holes 142 c to progressively adjust the height of the leg unit 120 while the height adjustment member 142 rotates based on a shaft 142 a ′ thereof, the height adjustment unit 140 being combined with an inner side of an upper bracket 121 of the leg unit 120 . The above description will be described in more detail.
In the height-adjustable table 100 , the leg unit 120 includes: upper and lower brackets 121 and 121 ′ each having a longitudinal guide hole 121 a with which the lifting unit 122 is combined, the upper and lower brackets 121 and 121 ′ being fixed at locations under the upper plate 110 ; the lifting unit 122 including a plurality of lifting members mounted to the upper and lower brackets 121 and 121 ′ in a scissor type, wherein a first end of each of the lifting members is held by a rotation guide shaft 122 a , and a second end thereof is combined with a guide roller 122 b to guide a movement of the lifting member along the longitudinal guide hole 121 a , the guide roller 122 b having the locking protrusion 122 b ′ protruding therefrom; and an elastic member 123 provided between the lifting members, thereby preventing the lifting unit 122 from being lowered too rapidly.
The elastic member 123 includes two springs having different diameters.
The leg unit 120 further includes: an auxiliary spring 124 provided to elastically lift or lower the lifting unit 122 , the auxiliary spring 124 being combined with the rotation guide shaft 122 a of the lifting unit 122 .
The height adjustment unit 140 includes: a fixed member 141 fixed to the inner side of the upper bracket 121 of the leg unit 120 ; the height adjustment member 142 combined with the fixed member 141 and adjusting the height of the leg unit 120 while rotating based on the shaft 142 a ′ thereof when the actuation unit 130 is operated; and a restoration member 143 provided between the fixed member 141 and the height adjustment member 142 , and restoring the height adjustment member 142 to the initial position thereof.
The height adjustment member 142 includes: a height adjustment body 142 a rotated based on the shaft 142 a ′ of the height adjustment member 142 by the operation of the actuation unit 130 ; a pressure protrusion 142 b provided on an upper part of the height adjustment body 142 a; and the plurality of height adjustment holes 142 c which are engaged with or released from the locking protrusion 122 b ′ of the leg unit 120 , the height adjustment holes 142 c being provided on a lower part of the height adjustment body 142 a.
The height-adjustable table 100 further includes: a cooperation unit 150 provided between and combined with the height adjustment units 140 placed at opposite sides of the table and configured such that the height adjustment units 140 are operated simultaneously while the cooperation unit 150 cooperates with the pressure of the pressure member 132 .
The cooperation unit 150 includes: a cooperation guide member 152 rotating based on a central shaft 152 ′ thereof; and cooperation members 151 connected with two opposite ends of the cooperation guide member 152 , respectively, the cooperation members 151 cooperating with the cooperation guide member while rotating based on the cooperation guide member 152 when the actuation unit 130 is operated, the cooperation members 151 having respective combination notches 151 ′ combined with the pressure protrusions 142 b provided in the height adjustment units 140 .
The fabrication process of the exemplary embodiment of the present invention constructed above will be described in detail below.
First, the upper plate 110 made of wood and formed to be flat as illustrated in FIGS. 1 and 2 is turned over so that the lower surface of the upper plate 110 faces upward.
After the upper brackets 121 are arranged at opposite positions spaced at a predetermined distance on the lower surface of the upper plate 110 and are mounted thereto, while the fixed mount 131 a is fixed to be adjacent to the outside of each of the upper brackets 121 , the actuation lever 131 is combined with the fixed mount 131 a by using the shaft pin 131 b so that the actuation lever 131 can rotate.
The pressure member 132 pressurizing the height adjustment member 142 is mounted to be in close contact with the inner surface of the actuation lever 131 .
In addition, the fixed member 141 of each of the height adjustment units 140 is fixed to the inner side of each of the upper brackets 121 , and the height adjustment member 142 having the height adjustment holes 142 c is located between the upper bracket 121 and the fixed member 141 , and then the shaft 142 a ′ of the height adjustment member 142 is combined with the height adjustment member 142 toward the side of the height adjustment member 142 from the outside of the fixed member 141 so that the height adjustment member 142 can rotate.
In this case, the pressure member 132 of the actuation unit 130 is in close contact with the pressure protrusion 142 b of the height adjustment member 142 so that when the pressure member 132 is pressurized, the height adjustment member 142 can rotate.
The restoration member 143 is mounted between the fixed member 141 and the height adjustment member 142 , wherein the first end of the restoration member 143 is mounted to one side of the height adjustment member 142 and the second end thereof is mounted to the inner surface of the fixed member 141 .
As described above, when the fabrication of the height adjustment units 140 is completed, the cooperation unit 150 simultaneously operating the height adjustment units 140 during the operation of the actuation unit 130 is provided between and combined with the height adjustment units 140 . After the combination notches 151 ′ formed on the cooperation members 151 of the cooperation unit 150 are combined with the pressure protrusions 142 b of the height adjustment members 142 , opposing ends of the cooperation members 151 are connected with respective opposite ends of the cooperation guide member 152 .
The cooperation guide member 152 is mounted to rotate based on the central shaft 152 ′ thereof located between the height adjustment units 140 .
Additionally, a first end of each of the lifting members provided in a scissor type is held to the upper and lower brackets 121 and 121 ′ by the rotation guide shaft 122 a so that the lifting members can rotate, and the guide roller 122 b is mounted to a second end of each of the lifting members to be guided in rolling contact with the inner surfaces of the upper and lower brackets 121 and 121 ′. The locking protrusion 122 b ′ of the guide roller 122 b is provided protruding toward the side of the longitudinal guide hole 121 a to be combined with one of the height adjustment holes 142 c of the height adjustment members 142 .
The elastic member 123 including a spring provided under the upper plate 110 and between the lifting members is connected with the lifting members to prevent the lifting unit 122 from being lowered too rapidly and to lift the lifting unit 122 elastically when the lifting members are lifted.
In the elastic member 123 , the spring is a double spring in which a small diameter spring is inserted into a large diameter spring, and the elastic member 123 prevents the lifting unit 122 from being lifted and lowered too rapidly.
Furthermore, the auxiliary spring 124 is mounted to the rotation guide shaft 122 a of the lifting unit 122 to help the lifting or lowering motion of the lifting unit 122 .
The operation of the exemplary embodiment of the present invention constructed as described above will be described in detail below.
First, as illustrated FIGS. 3 to 7 , when it is required to lift a folded table to a predetermined height by closing the leg units 120 , a user holds and presses at least one of the actuation levers 131 of the actuation units 130 .
If the actuation lever 131 rotates based on the shaft pin 131 b thereof, the pressure member 132 positioned at one end of the actuation lever 131 pressurizes one surface of the pressure protrusion 142 b of the height adjustment member 142 .
Then, the height adjustment member 142 is rotated based on the shaft 142 a ′, and the cooperation members 151 of the cooperation unit 150 combined with the pressure protrusions 142 b of the two height adjustment units 140 provided at opposite sides of the table rotate based on the cooperation guide member 152 to simultaneously rotate the height adjustment members 142 .
In this case, the locking protrusion 122 b ′ of the lifting unit 122 locked in one of the height adjustment holes 142 c is released therefrom.
When the locking protrusion 122 b ′ is released from the height adjustment hole 142 c of the height adjustment member 142 as described above, the user vertically lifts the upper plate 110 to the predetermined height while holding the actuation lever 131 of the actuation unit 130 .
When the upper plate 110 is lifted, the lifting members of the lifting unit 122 rotate based on a rotation shaft 122 ′, and the guide rollers 122 b move in rolling contact with the upper and lower brackets 121 and 121 ′. During the movement of the rollers 122 b , the locking protrusions 122 b ′ of the guide rollers 122 b are simultaneously guided along the longitudinal guide holes 121 a.
In this case, the movement of the locking protrusion 122 b ′ is not interrupted from the height adjustment hole 142 c of the height adjustment member 142 .
When the upper plate 110 reaches a desired height, the user removes the pressure from the actuation lever 131 .
When the pressure of the actuation lever 131 is removed, the height adjustment member 142 rotates based on the shaft 142 a ′ by the elasticity of the restoration member 143 mounted between the height adjustment member 142 and the fixed member 141 , thereby restoring the position of the height adjustment member 142 to the initial position thereof. At the same time, the locking protrusion 122 b ′ of the lifting unit 122 is locked in one of the height adjustment holes 142 c of the height adjustment member 142 , thereby realizing adjustment of the height of the leg unit 120 .
In this case, when the height adjustment member 142 rotates, the pressure member 132 pressurizing the pressure protrusion 142 b is moved toward the actuation lever 131 by the restoring force of the height adjustment member 142 , thereby rotating the actuation lever 131 to the initial position thereof.
In addition, the cooperation members 151 combined with the pressure protrusions 142 b of the height adjustment members 142 provided at the opposite sides of the table rotate based on the central shaft 152 ′ of the cooperation guide member 152 , thereby restoring the position of the cooperation member 151 to the initial position thereof.
To lift the height of the upper plate 110 higher after adjusting the height of the upper plate 110 as described above, the same process described above may be applied to adjust the height of the upper plate 110 .
Accordingly, as described above, the upper plate 110 is vertically lifted to progressively adjust the height thereof.
In addition, as illustrated in FIGS. 8 and 9 , the height-adjustable table 100 having the above-mentioned construction may be used while being put in a table 100 ′ having a receiving space A.
Here, the height of the upper surface of the height-adjustable table 100 is equal to the height of the table 100 ′ having the receiving space A, so the height-adjustable table 100 put in the table 100 ′ may be used as a normal table. When it is required to lift the upper plate 110 of the height-adjustable table 100 to a predetermined level, the upper plate 110 may be lifted to the desired height by operating the actuation unit 130 in the same manner as described above.
All terms or words used in the specification and claims have the same meaning as commonly understood by one of ordinary skill in the art to which inventive concepts belong. 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.
Although a preferred embodiment of the present invention has been described 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. | Provided is a height-adjustable table configured such that a height adjustment member rotates in response to an operation of an actuation unit, thereby being released from a locked state, and when an upper plate of the table is vertically lifted to a desired level, the operation of the actuation unit is stopped, and the height of the upper plate is adjusted step by step. Optimal space utility and a simple inner structure of the height-adjustable table can be accomplished, thereby reducing manufacturing cost and increasing user convenience. | 0 |
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
This invention relates to an apparatus and method of anchoring uprights in the ground and, more particularly, to a removable screw-type, in-ground anchor device that provides a secure foundation for uprights in any type of soil without using concrete.
2. Description of Related Art
At present, most uprights such as fence posts and sign posts are anchored in the earth by digging or drilling a hole in the ground, pouring concrete in the hole, and securing the base of the upright in the concrete until it dries. The process is tedious, labor intensive, and causes additional delays due to the drying and curing time of the concrete. Additionally, the uprights are extremely difficult or impossible to remove if the fence or sign post needs to be taken down or repositioned at a future date.
Past attempts to improve the foundation and anchoring of uprights have met with only limited success. A typical attempt is described in U.S. Pat. No. 5,295,766 to Tiikkainen. Tiikkainen discloses a foundation for uprights that includes a tubular drive-shaft that is equipped with a large helical auger at the base. In operation, a conical section above the auger serves to compact a soil layer softened by the rotation of the helical auger. However, the diameter of the auger is much greater than the widest diameter of the conical section and the outside diameter of the tubular drive-shaft. Therefore, the auger softens the soil surrounding the drive-shaft for a considerable distance beyond the outside diameter of the shaft. The conical section is then unable to compact the soil sufficiently to provide a secure foundation for the upright. Additional steps such as pouring concrete must be taken to reinforce the foundation. Thus, the soil conditions in which Tiikkainen can operate are limited, and Tiikkainen does not teach or suggest a screw-type, in-ground anchor device that provides a secure foundation for uprights without the use of reinforcing concrete.
In order to overcome the disadvantage of existing solutions, it would be advantageous to have a removable screw-type, in-ground anchor device that provides a secure foundation for uprights such as fence posts, sign posts, and street lights in any type of soil without using concrete. The present invention provides such a device.
SUMMARY OF THE INVENTION
In one aspect, the present invention is a removable screw-type, in-ground anchor device that provides a secure foundation for uprights such as fence posts, sign posts, and street lights in any type of soil without the necessity of using concrete. The anchor device includes a generally cylindrical drive shaft with a set of screw threads (flightings) mounted near the lower end. The drive shaft includes a cylindrical housing portion of a first diameter at an upper end of the drive shaft for supporting the above-ground upright. A shallow-sloped conical portion connects the housing portion to a tip portion that has a second diameter substantially less than the first diameter. The conical portion has a surface with a diameter that decreases from the first diameter to the second diameter over a longitudinal distance that provides a slope to the surface of less than 20 degrees, and preferably in the range of 5-10 degrees. The flightings are attached to the tip portion and have a third diameter that is approximately equal to the first diameter. The flightings operate in soil to screw the anchor device into the ground when the device is rotated.
In another aspect, the present invention is a screw-type, in-ground anchor device for anchoring an above-ground upright in all types of soil. The anchor device includes a cylindrical upper housing portion with a diameter sized to accept the above-ground upright. A set of flightings are mounted near a bottom end of the anchor device, and impart downward force on the anchor device when the anchor device is rotated. The flightings having a diameter approximately equal to or less than the diameter of the housing portion. The flightings disrupt the soil in their wake, and a conical portion having a slope of less than 20 degrees, and preferably in the range of 5-10 degrees, outwardly compresses the soil in the wake of the flightings. The outward compression of the soil creates a tightly compressed soil shaft having the same diameter as the housing portion.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawings, in conjunction with the accompanying specification, in which:
FIG. 1 is an elevational view of the preferred embodiment of the screw-type, in-ground anchor device of the present invention;
FIG. 2 is a perspective view of the top of the upper housing portion of the anchor device and a T-handle manual insertion tool;
FIG. 3 is a perspective view of the top of the upper housing portion of the anchor device in an alternative embodiment and an X-handle manual insertion tool;
FIG. 4 is a top plan view of a first embodiment of a manual insertion wheel for use with the anchor device;
FIG. 5 is a top plan view of a second embodiment of a manual insertion wheel for use with the anchor device; and
FIG. 6 is a perspective view of an adapter configured for use with a core drill chuck to mount a T-handle on a core drill for machine insertion of the anchor device into the ground.
DETAILED DESCRIPTION OF EMBODIMENTS
FIG. 1 is an elevational view of the preferred embodiment of the anchor device 10 of the present invention. The present invention is a screw-type, in-ground anchor device for receiving above ground uprights such as vertical posts, poles, or tubing. The device comprises a tip portion 11 , flightings 12 , a shallow-sloped conical portion 13 , and a cylindrical upper housing portion 14 for receiving the above ground upright. The flightings have a diameter that is approximately equal to, but preferably slightly less than, the diameter of the upper housing portion. For example, in one embodiment designed for supporting fence posts, the outside diameter of the upper housing portion is 2⅞ inches and the diameter of the flightings is 2⅝ inches.
The flightings have a 1-inch spacing (i.e., 1-inch pitch) which causes the device to move ½ inch into the ground for each revolution. In the fence post embodiment, the flightings extend over a longitudinal distance of approximately 4-inches. The flightings are welded to the tip portion 11 and partially up the conical portion 13 . The weld overlaps the tip of the conical portion to provide a stronger weld.
As the device is screwed into the ground, the conical portion 13 works as a packing device. The flightings 12 disrupt the soil only within the diameter of the upper housing portion 14 , and the conical portion then outwardly compacts the soil to form a tightly packed soil shaft that tightly encloses the device 10 and holds it solidly in place. The conical portion has a shallow slope of less than 20 degrees, and preferably in the range of 5-10 degrees from the vertical. The shallow slope causes the soil to be compacted slowly as the device moves into the ground. Some looser soils may be compacted with conical slopes up to 20 degrees, but for denser soils, slopes of 5-10 degrees are preferable. Since the soil is being gradually compacted, less downward force must be generated by the flightings, thereby enabling the smaller flightings of the present invention to be utilized.
If the slope of the conical portion is steeper, as in some prior art devices, the flightings must generate more downward force in order to move the device through the ground and outwardly compact the soil in a shorter distance. Under these conditions, the smaller flightings utilized in the present invention would strip out the soil and spin uselessly in the hole. Prior art devices made the mistake of overcoming this problem by making the flightings larger so that they could produce more force. Prior art designers also had the mistaken belief that large flightings would provide a stable base for the device. However as noted above, large flightings have the detrimental effect of disrupting the soil in a large area surrounding the device as it moves into the ground, producing a less stable anchor. Therefore, reducing the diameter of the flightings to a diameter less than the outside diameter of the upper housing portion, and decreasing the slope of the conical section to less than 20 degrees produces the unexpected result of a more stable anchor.
Thus, the present invention provides the dual features of (1) disrupting the soil only within the diameter of the device itself, and (2) gradually compacting the disrupted soil outwardly as the device is pulled into the ground by the rotating flightings. In combination, these features result in a tightly packed soil shaft the exact diameter of the upper housing portion of the device.
The overall length of the device 10 is determined by the diameter and length of the vertical upright to be mounted in it, and the type of soil. For stability, the housing portion 14 should be long enough to accept about 25-30% of the length of the vertical upright. The length of the conical portion 13 is derived from the outside diameter of the upper housing portion (variable), the diameter of the tip portion (¾ inches), and the 5-10 degree slope of the cone. For the fence post embodiment, the conical portion is approximately 9 inches from the bottom of the housing portion 14 to the top of the tip portion 11 .
The preferred embodiment of the present invention utilizes the tip portion 11 to provide vertical stability when the anchoring device is first started into the ground. In an alternative embodiment, the tip portion may be omitted, and the flightings attached to the lower part of the conical portion 13 . However, without the tip portion, it is more difficult to keep the device plumb. The tip portion may be constructed by machining a point on a ¾-inch steel rod. In addition, one or two opposing vertical notches 15 are placed in the tip at the leading end to initially disrupt the soil in dense soil conditions, and to enable the tip to break up small rocks or dislodge them as the device penetrates the soil. Experimentation has shown that if the tip has a plain point, any impediment in the soil, such as a small rock, tends to deflect the anchoring device from the vertical as it is being inserted. When the tip is notched, however, the rock is either broken away or pushed to the side. If the tip hits the rough edge of a rock, the notch chips the rock, and the device remains plumb. Smooth rocks are pushed aside. As the device continues into the ground, the rock is pushed to the side by the conical portion, and does not affect the proper orientation of the device.
Additionally, if a plain tip hits an impediment such as a gas line, PVC water pipe, or electrical line, even though the object is smooth and rounded, the tip is likely to damage the pipe or line. However, when the notched tip hits a smooth rounded object such as a pipe or line, experimentation has shown that the tip pushes the pipe or line to the side and does not damage it.
In the fence post embodiment, the length of the rod making up the tip portion 11 is 5½ inches from the tip of the conical portion 13 to the leading end. The part of the tip portion that extends beyond the flightings is about 2½ inches. This configuration is for a tighter soil such as clay or black dirt. Sand, sandy loam, or gravel require different configurations with a longer tip. The longer tip provides more stability in looser soils.
Longer tip portions may also be used for anchor devices being inserted into lake bottoms or river beds. Uprights that go into a lake bottom or river bed currently have to be pile-driven into the soil under the lake or river. For most lake or river beds, there is a clay layer of the soil that actually holds the water, and the local water table is some distance below the clay layer. Accurate information about the depth of the water table is often not available, therefore, the distance from the bottom of the lake to the water table is not known. Pile driven poles driven into the bottom of a small pond may actually penetrate the clay layer, causing the pond to drain into the water table below.
The present invention, however, can be screwed into the lake bottom much quicker, and forms a plug in the underlying clay layer, thereby preventing the pond from being inadvertently drained. A coupling such as that described later in FIG. 6 may be utilized to attach the present invention to a drill. For different water depths, additional pipe sections may be added as required, much like drill stem pipe on an oil rig. For anchor devices designed for lake bottoms or river beds, the tip portion 11 may be as long as 12 or 13 inches. When the tip portion starts to penetrate the clay layer, the rotating flightings 12 screw into the clay soil, and the conical portion 13 tightly compacts the clay around the device. This creates a tight plug, providing a solid anchor for an upright while preventing the draining of the pond.
The diameter of the anchoring device may vary in order to support uprights of various diameters. For different diameters, the dimensions of the device are scaled up or down so that the anchor device retains approximately the same proportions. For example, while the conical portion of the fence post embodiment has a maximum outside diameter of 2⅞ inches and a length of 9 inches, a slightly larger version may have a maximum outside diameter of 3⅛ inches, and a conical portion 11 inches long, thus maintaining the slope of the conical portion at approximately 5-10 degrees. Known applications may vary from 2⅜ inches (inside diameter) for a fence post to 8 inches (inside diameter) for a street light or telephone pole. For highway signs, the inside diameter of the housing is approximately 4 inches.
For larger diameters such as 8 inches, it may be necessary to pre-drill a central bore hole due to the amount of soil to outwardly compact. The central bore hole may be as large as 6 inches in diameter and 24 inches deep. The depth of the central hole is less than the length of the device since the flightings 12 have to be screwed into the soil at the bottom of the bore hole in order to cause the compacting by the conical portion 13 .
Uprights such as street lights commonly mount on a base plate. For uprights mounting on a base plate, the base plate is mounted on the top of the upper housing portion, and the street light, instead of being inserted into the housing, is mounted on the base plate.
The preferred embodiment of the anchoring device 10 is made of ¼-inch rolled steel, although the thickness and composition may vary according to the soil conditions and the size of the upright. The device may also be constructed of a hard polymer or a polymer/steel-strand mixture that can be formed in an injection mold. The preferred embodiment is hollow from the top of the upper housing portion 14 to the bottom tip of the conical portion 13 . Alternatively, the conical portion may be solid, but it makes the device heavier and more expensive. In fact, for uses where a mounting plate is used on the top to mount uprights such as a light pole, the entire device may be solid, but once again, it makes the device heavier and more expensive.
The anchoring device can be inserted manually with an insertion tool or by machine. FIG. 2 is a perspective view of the top of the upper housing portion 14 of the anchor device, showing the void 20 formed inside the housing portion 14 , and a T-handle manual insertion tool 21 . The manual insertion tool may be a piece of pipe or steel rod that can be used as a T-handle when placed in the insertion slots 22 on the top of the housing. One or more people then rotate the device with the T-handle. A level indicator 23 may be mounted on the T-handle to ensure the anchoring device remains plumb.
FIG. 3 is a perspective view of the top of the upper housing portion 14 of the anchor device in an alternative embodiment and an X-handle manual insertion tool 31 . In this embodiment, the anchoring device 10 is provided with four insertion slots 22 on the top of the housing at 90-degree spacing. The X-handle is equipped with a leveling device which may be, for example, a circular bubble-level 32 mounted in the center of the X-handle. Alternatively, two opposing slots can be cut to a depth twice the diameter of the pipe, so that one T-handle can be placed in the deeper slots, and a second T-handle can be used in the shallow slots in a perpendicular orientation.
FIG. 4 is a top plan view of a first embodiment of a manual insertion wheel 41 . In this embodiment, a loop 42 is mounted at the ends of a plurality of radiating spokes 43 to create a manual insertion handle similar to a steering wheel. Here again, a circular bubble-level 32 may be mounted in the center of the wheel to keep the anchoring device plumb as the device is inserted into the ground.
FIG. 5 is a top plan view of a second embodiment of a manual insertion wheel 51 . In this embodiment, a loop 52 is mounted near the ends of a plurality of radiating spokes 53 to create a manual insertion handle similar to a ship's wheel. Here again, a circular bubble-level 32 may be mounted in the center of the wheel to keep the anchoring device plumb as the device is inserted into the ground.
FIG. 6 is a perspective view of an adapter 61 configured for use with a core drill chuck 65 to mount a T-handle similar to the T-handle 21 on a core drill 66 for machine insertion of the anchor device into the ground. For insertion by a machine, a hand-held or crane-mounted core drill 66 may be utilized to rapidly insert the device into the ground while reducing human labor. The adapter 61 includes a shank 62 which is inserted into the core drill chuck 65 . The shank is mounted to a cylindrical body 63 with mounting brackets 64 . The cylindrical body of the adapter has an outside diameter that is equal to the inside diameter of the upper housing portion 14 of the anchor device 10 . In operation, the cylindrical body 63 is inserted into the upper housing portion 14 , and the T-handle 21 is inserted into the insertion slots 22 . The core drill is then used to insert the anchor device into the ground. Generally, a hand-held core drill may be used to insert anchoring devices up to approximately 3 inches in diameter. The crane-mounted core drill is preferable for larger diameters. A power takeoff (PTO) auger on a tractor can also be used to insert anchoring devices up to approximately 5 inches in diameter.
The anchoring device is reusable, and can be easily extracted from the ground and reinserted in a new location. This makes the device useful for temporary signage, fencing, or utility poles, etc. Reversing the direction of rotation causes the flightings 12 to back out until they reach the void created by the previous position of the conical portion 13 . The device can then be simply lifted out of the hole.
It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. While the apparatus shown and described has been characterized as being preferred, it will be readily apparent that various changes and modifications could be made therein without departing from the scope of the invention as defined in the following claims. | A screw-type, in-ground anchor device for anchoring an above-ground upright. A generally cylindrical drive shaft includes an upper cylindrical housing portion constructed of ¼-inch rolled steel with an inside diameter sized to match the outside diameter of the upright. A conical portion connects the upper housing portion to a lower tip portion. The surface of the conical portion has a slope of less than 20 degrees, and preferably in the range of 5-10 degrees. A set of screw threads (flightings) are attached to the tip portion and have a diameter that is approximately equal to or less than the diameter of the upper housing portion. The flightings operate in soil to screw the anchor device into the ground when the device is rotated. The conical portion outwardly compresses the soil that is disrupted in the wake of the flightings. Since the flightings have a diameter approximately equal to or less than the diameter of the upper housing portion, soil surrounding the drive shaft is not disrupted. Therefore, the outward compression of the soil creates a tightly compressed soil shaft having the same diameter as the housing portion. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to a protective cover for the work area of a machine tool comprising a plurality of frame-like segments disposed so as to be limitedly shiftable within each other and respectively provided with a sealing strip on at least one edge and connecting elements formed as slidable lattice grates connecting the frame-like segments, the respective link pins of the slidable lattice grates being fixed to a rear segment of a respective segment.
[0003] 2. Background
[0004] Protective covers of this type generally comprise a plurality of frames arranged so as to be relatively shiftable within each other, the outermost one of the frames being fixedly connected to a component of the machine tool and the innermost frame being attached to a machine slide or a spindle housing movable in at least one coordinate axis. An example of such a protective cover is shown in EP 0 673 712. The frames are formed of a resistant sheet metal and comprise a broad front bridge or segment which forms the effective part of the protective cover and is provided with a sealing strip at its edge section, a transverse bridge and a shorter rear segment extending parallel to the front segment. The broad front segments of the adjacent segments overlap each other so that all of the bridges together form a virtually continuous protective wall. The inner frames or frame-like segments are shiftably disposed in the respective outer frames having the same shape and greater dimensions and connected to each other by connecting elements formed as slidable lattice grates, the respective link pins of the slidable lattice grates being permanently fixed to a rear segment of a respective segment. In practice, work-related problems have occurred when maintenance and repair work had to be carried out and the protective cover had to be totally or partially removed for this purpose. In such cases not only the frame-like segments but also the slidable lattice grates, including the respective guiding and attachment elements of the protective cover and therefore the whole protective cover, had to be removed, which entailed a significant amount of work.
SUMMARY OF THE INVENTION
[0005] According to the invention the desired reduction of the mounting operations on a machine tool is accomplished by detachably fixing slidable lattice grates to the frame-like segments. By releasing the connecting means between the respective slidable lattice grate or its link pins and the associated frame-like segment, one or more of the frame-like segments may be removed while the slidable lattice grates, including their attachment and guiding elements, remain on the machine.
[0006] An embodiment of the releasable attachment means which is, on the one hand, stable, and, on the other hand, easily movable, is characterised in that the link pins attached to the narrower rear segments of the frame-like segments are surrounded by a flange sleeve on which the two crossed arms of the slidable lattice grate are non-detachably supported, the flange sleeve being detachably connected to the associated link pin. Efficiently the flange sleeve contacts a distance shim fixedly connected to the respective segment with its flange and is detachably connected to the respective link pin through a disk as well as by a screw. The largely dimensioned support of the flange sleeve on the distance shim by means of its flange ensures a tilting-free positioning of the flange sleeve, and the end side screw connection provides a safe, bilateral fixation of the two arms of the slidable lattice grate which are pivotable with respect to each other.
[0007] A particularly efficient further development of the invention is characterised in that the frame-like segments are, at least partly, particularly in their lower segments, held in tight mutual contact by a resilient pressure. With the resilient pressure acting on the frame-like segments a tight contact of their wide front side segments is achieved so that gaps between the two front bridges or segments of adjacent frame-like segments, through which flushing liquid or chips might enter the space behind the protective cover, are avoided. The resilient pressure forces acting on the individual segments should be finely adjustable so that the ready movability of the frames is not affected during their relative movements. The elastic abutment should, however, be sufficiently large to ensure a sufficiently tight contact of the edge side sealing strips of one segment to the wider front segments of the adjacent segment so that a wiper effect is accomplished during the shifting movements of the frame-like segments. An effective resilient pressure acting on two frame-like segments may be achieved in a technically simple manner by rendering at least some link pins of the slidable lattice grates spring-biased and having them disposed axially movable within their flange sleeves. To maintain the spring bias a pressure spring acting on the link pin may be provided in a jack surrounding the end portion of a link pin.
BRIEF DESCRIPTION OF THE DRAWING
[0008] The objects, features, and advantages of the invention will be more clearly perceived from the following detailed description, when read in conjunction with the accompanying drawing, in which:
[0009] FIG. 1 is a schematic front view of an embodiment of the protective cover of the invention for the work area of a machine tool;
[0010] FIG. 2 is a cross sectional view of a plurality of the frame-like segments of the protective cover shown in FIG. 1 fully inserted into each other, together with their connection means; and
[0011] FIG. 3 is a cross sectional view of a plurality of the frame-like segments of the protective cover shown in FIG. 1 fully inserted into each other, together with their spring-biased connection means.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] With reference to the drawing, and more particularly to FIGS. 1 and 2 , a protective cover in accordance with the invention is shown which comprises rectangular, rigid outer frame 1 having a broad front segment 2 covered by profiled sheet metal 3 . The front segment rests on sealing strip 4 at its edge. Angle section 5 is connected to broad plane segment 2 , the angle section being fixed to the vertical bridge of angular beam 7 by means of angle profile 6 , using screws 8 , for example. In the inner space covered by outer frame 1 are provided three respectively frame-like segments 9 , 10 , 11 , each comprising an upper sheet metal strip, these frame-like segments 9 , 10 , 11 being slid into each other in the illustrated embodiment. On the right edge ( FIG. 2 ) of each sheet metal strip of segments 9 , 10 , 11 , respective sealing strip 4 is fixed to the upper side. The width of the sheet metal strips of segments 9 , 10 , 11 is chosen so that sealing strips 4 are overlapping with a slight lateral displacement in the illustrated, fully inserted operating state. As can be seen in FIG. 2 , the left edge of the sheet metal strip of the segment 9 is connected to an L-shaped, rigid profile sheet, narrower lower segment 13 of which is bent to the outside and carries reinforcing beam 12 in the angle area. The sheet metal strips of frame-like segments 10 , 11 are also fixedly connected to L-shaped, rigid sheet metal profiles on their left edge, horizontal segments 14 , 15 of these sheet metal profiles pointing inward. Under frame-like segment 11 a flat frame 17 is provided which comprises a plane metal sheet 18 and a support plate 19 attached to its bottom side. Right-angle bend 20 provided on its right edge, the height of which approximately corresponds to the height of the segment package. Right-angle bend 20 is fixed to a machine part (for example, a spindle head) movable in two coordinate axes.
[0013] On the bottom side of horizontal segment 8 of beam 7 is link pin 24 permanently attached to segment 8 . Two arms 25 , 26 of a slidable lattice grate are pivotably supported on link pin 24 . Locating disk 27 is detachably fixed to the end of link pin 24 by means of bolt 28 .
[0014] On rear horizontal segments 13 , 14 , 15 of frame-like segments 9 , 10 , 11 further link pins 30 are permanently attached via spacers 31 of different thicknesses. On each link pin 30 is provided detachable flange sleeve 32 . This flange contacts a large area of the respective spacer 31 . On each flange sleeve 32 the respectively two arms 33 , 34 of one of the four slidable lattice grates A, B, C, D (shown in dashed lines in FIG. 1 ) are supported in roller bearings shown in FIG. 2 . Cheaper plain bearings, or other operative bearings could also be used. On the free end portion of each flange sleeve 32 is spacer ring 35 . On spacer ring 35 is annular or ring-shaped disk 36 which is in engagement with the end portion of flange sleeve 32 by means of a collar-shaped extension. This engagement may be by means of a threaded connection. Disk 37 is pressed against the outer surface of disk 36 by suitable means such as stud bolt 38 screwed into the face of the narrow end portion of link pin 30 . After the removal of stud bolt 38 and the detachment of pressure disk 37 it is possible to obtain axial release movement between respective link pin 30 and the assembly comprising flange sleeve 32 , arms 33 , 34 of the slidable lattice grate supported on the flange sleeve, spacer ring 35 , and ring-shaped disk 36 .
[0015] On the support sheet 19 of lowest, plane, frame-like segment 18 , support arm fastening 40 is directly and permanently fixed. The two ends of the inner arms 33 , 34 of the slidable lattice grate are supported on the narrower pivoting pins 41 of support arm fastening 40 . An end side safety disk 43 attached to pivoting pin 41 , typically by means of stud bolt 44 , prevents an axial displacement of arms 33 , 34 on pin 41 .
[0016] The protective cover shown in a partial cross section in FIG. 3 corresponds to the embodiment according to FIG. 2 to a large extent so that components corresponding to each other are indicated by the same numerals. In this case also the frame-like segments are in their fully inserted state, that is, the spindle head possibly built into right-angle bend 20 of lower, plane segment 18 is in the right end position. The three connecting means between the three frame-like segments 9 , 10 , 11 and the slidable lattice grates differ from those of the embodiment shown in FIG. 2 . The connecting means also comprise link pins 30 on which flange sleeves 32 are supported in roller or plain bearings. Instead of the pressure or spacer ring shown in FIG. 2 , bowl-shaped support 50 may be screwed into the inner space of flange sleeve 32 via a collar-shaped extension is used in this FIG. 3 embodiment. The narrower end portion of link pin 30 to which disk 52 is fixed by means of screws protrudes into bowl-shaped support 50 . The bowl-shaped support is closed to the outside by termination disk 54 , preferably detachably fixed by means of screws. Between termination disk 54 and disk 52 , and fixed on link pin 30 , is mounted pressure spring 55 . This pressure spring is supported by termination disk 54 and exerts an axial force on link pin 30 . That force is transmitted to the frame-like segment which is pushed against the adjacent frame-like segment with its sealing strip 4 in this way whereby a sufficiently tight contact is achieved and therefore a leakage and an entry of chips are prevented even during mutual displacement movements of the segments. The pressing forces generated by the various pressure springs 55 are finely adjustable so that, on the one hand, a sufficiently tight contact of the sealing strips 4 is achieved and, on the other hand, the frame-like segments remain readily movable during their shifting movements.
[0017] In case of the connecting means shown in FIG. 3 , the individual segments may also be separated from the bearings of the arms of the slidable lattice grates in an easy manner to remove the frame-like segments without having to detach the slidable lattice grates. Instead of springs 55 other suitable pressure elements may be used which generate corresponding pressure forces due their resilient deformability. | A protective cover for the work area of a machine tool having a plurality of frame-like segments disposed so as to be limitedly shiftable within each other and respectively provided with a sealing strip on at least one edge. A plurality of connecting elements formed as slidable lattice grates connect the frame-like segments, the respective link pins of the slidable lattice grates being fixed to a respective rear segment of a segment. For simplified assembly and removal of the protective cover the slidable lattice grates are detachably fixed to the frame-like segments. | 8 |
FIELD OF THE INVENTION
[0001] The invention is in the field of manufacture of tubular metal workpieces and relates to forming tools, especially piercing plugs, forging mandrels and rolling mandrels with improved stability.
STATE OF THE ART
[0002] Seamless steel tubes are generally made in three forming stages on respective rolling mills by hot forming. In a first stage, on a so-called cross-roll piercing mill a solid steel block heated to about 1200° C. is pierced by means of an internal tool, the piercing plug, into the hollow bloom. Here, the block is driven by means of inclined rolls over the piercing plug. In the second forming stage, in a longitudinal rolling process the hollow bloom is reduced over the inner tool, a rolling mandrel, in diameter and wall thickness and stretched in the longitudinal direction. In the third forming stage, the rolling stock is converted to the required dimensions in diameter and wall thickness, where usually no internal tool is used.
[0003] The inner tools in the first two forming stages are exposed in the production to high temperatures and mechanical pressures. In most cases, the inner tools are made of heat resisting steel. In the production, especially with larger rolling times a successive heating of the internal tool is often unavoidable. Due to heating the strength of the tool decreases and the tool can no longer withstand the mechanical stresses. The tool deforms and breaks.
[0004] To achieve a long service life, piercing plugs are provided with natural scale layers. These scale layers inhibit the flow of heat from the workpiece to be shaped into the tool and protect the tool from rapid heating and rapid loss of strength. When forming higher alloyed materials, the scale layer is removed, however, quickly and the thermal protection fails.
[0005] In rolling mandrels scaled tools or tools provided with a chromium layer are used depending on the forming process course. Corresponding piercing plugs are known from German Patent Application DE10 2008 056 988 A1 (SMS MEER). A disadvantage, however, is that the thermal insulation against the heat flow from the workpiece to be shaped into the tool is low. Thus, particularly with internal tools, which are used at reduced speed and length of contact, heating of the inner tool and its failure due to deformation and fracture occur.
[0006] The tool life could be improved if the thickness of the oxide layer could be enlarged. Then, the thermal insulation is better and during abrasive wear the protective layer would remain preserved longer.
[0007] The protective layer is formed naturally from the base material by conversion to iron oxides, but does not have high stability. It is brittle and porous and therefore can be easily destroyed by mechanical and thermal stress. Therefore, these protective layers are limited in thickness. The limit of the layer is about 0.8 mm. The protective effect of such a layer is therefore limited accordingly. Heat penetrates therefore into the main body of the tool and reduces its strength, whereby it then comes to premature failure of the tool. With high-alloyed work-pieces abrasion leads relatively quickly, i.e. by a small length of the rolled material to the removal of the protective layer.
[0008] From the international patent application WO2011 107214 A1 (SMS MEER) piercing plugs or rolling mandrels are known for the production of seamless tubes or forging mandrels for hot forging of tubular workpieces of metal which have a surface profiling, in which the oxide layer is applied. In this way, better adhesion and longer service life to be achieved.
[0009] Similar tools, in which the coating consists of molybdenum, are known from EP0385439A1 (NKK CORP.).
[0010] Subject of the European patent application EP 2404680 A1 (SUMITOMO) is the manufacture of steel tubes according to the Mannesmann process. Claimed is a piercing plug the feature of which is, that it inhibits a channel, through which a lubricant is lead during piercing. According to [0053] the piercing plug can be coated by iron. For this an iron wire is lead to a spraying device where it is molten. The molted iron is then sprayed onto the piercing plug, i.e. a continuous coating is developing.
[0011] In practice, the preparation of such profiled tools, however, proves to be expensive since the profiles have to be individually cut into the piercing plugs, and also lead to material losses. The manufacturing cost of a profile disproportionately increase with the size of the introduced grooves. An economic and feasibility limit is reached at just a few millimeters. Another disadvantage of the profile cut into the base body is the limitation of the material on good oxidizable steels. These have in particular a low chromium content and thus low hardness.
[0012] The object of the present invention has therefore been to provide hot forming tools with improved stability, which are free from the above-stated disadvantages. In particular, these tools should have an oxide layer having a higher strength compared to the prior art, which can be also applied easily and without loss of material.
DESCRIPTION OF THE INVENTION
[0013] A first aspect of the invention relates to a hot forming tool comprising a tool body having at least pro rata surface coating, which can be obtained, by that the basic body is provided with a raised metallic relief, which is subsequently completely or partially oxidized and converted into a protective layer.
[0014] Under ‘raised’ has to be understood, that the relief is raising related to the surface of the tool (‘hill structure’) and thus is contradictory to a profiling where profile grooves are carved into the surface (‘valley structure’).
[0015] Another aspect of the invention includes a method for producing a hot forming tool comprising a tool body having at least pro rata surface coating, in which
(a) the body is provided with a raised metallic relief, and (b) successively the metallic relief is completely or partially oxidized and converted into a protective layer.
[0018] The application of raised reliefs is the reverse case to a profiling of the tool. For the purposes of the invention, therefore, material is added and not removed. Surprisingly, it was found that the relief formation is in contrast to the profiling not only much easier to realize, but by complete or partial conversion of the relief material, even a considerably harder and thus more stable oxide film is obtained, which leads to a significant improvement in tool life. The invention also provides the possibility of selecting the relief material to vary the quality of surface protection and adjust the process conditions.
[0019] The economic benefit of the invention is obvious and is in particular in the reduction of tool costs during the production of steel products, as well as the extension of the rolling time, which is usually associated with larger lengths of the rolling stock and reduced material waste.
[0020] Tools
[0021] Hot forming tools of the present invention are preferably a piercing plug or a forging mandrel, which are typically made of steel. The invention includes under this preamble, however, in principle, any other metallic workpiece, in which the body is to be protected against heat influx. The term metal is not limited to iron and steel, but also includes other metallic materials including metal-composite materials that are to be supplied to a hot forming.
[0022] But not only in piercing plugs, the inner tools in piercing by cross rolling, with the other inner tools that are used in the production of seamless steel tubes, the surface coating of the invention may be advantageously employed. In the rolling mandrels, the inner tools in the rolling mills with several successively arranged roll stands in the second forming stage is particularly important to ensure that the friction between tool and rolling stock is low. Therefore, the surface layer of the invention has to be grinded and polished for this application. Also, an additional layer can be applied, made of chrome on the protective layer according to the invention.
[0023] The raised relief, which is applied to the base body can be pronounced quite differently, the alternative embodiments are all suitable in principle to fulfill the task in full.
[0024] In a first embodiment, it may be simply a wrapping of the body with a wire, preferably a steel wire at the raised relief.
[0025] In a second embodiment, the raised relief can represent a metal fabric or metal mesh, which is applied to the base body.
[0026] The metallic bodies applied to the surface of the tool are preferably made from a steel mesh, for example with a steel wire thickness of about 1 to about 5 mm and preferably about 1.5 mm and a mesh spacing of about 1 to 5 mm and in particular about 2.5 mm. Under the mesh spacing the distance of the center lines of two adjacent fabric elements is to be understood.
[0027] In a third embodiment the raised relief may be an irregular coating, as is achieved by chemical or physical deposition of metal from the vapor phase.
[0028] Relief Formation
[0029] The application of the raised reliefs can by very different—simple and complex—procedures, which yet solve all the object of the invention to the full extent.
[0030] In a first embodiment, the base body is simply wrapped with a wire, preferably a metal wire.
[0031] In a second alternative embodiment, a metal fabric or a metal mesh is used instead of the wire. This may be preformed, for example by forming the shape of the tool and then mounted on the base body. In order to increase the strength, it is advisable to weld the wire coil or the metal fabric to the base body.
[0032] In a third alternative embodiment, it is possible to produce the relief on the surface of the base body by chemical or physical vapor deposition (Chemical/Physical Vapor Phase Deposition, CVD/PVD).
[0033] The term chemical vapor deposition is a group of coating methods which are used inter alia in the manufacture of microelectronic components and optical waveguides. At the heated surface of a substrate, a solid component is separated due to a chemical reaction from the gas phase. A prerequisite is that volatile compounds of the component layers exist, the entrained solid layer at a given reaction temperature. The method of the chemical vapor deposition is characterized by at least one reaction on the surface of the workpiece to be coated. This reaction must be at least a gaseous starting compound (starting material) and at least two reaction products—to be involved—of which at least one in the solid phase. To over competing vapor phase reactions to promote those reactions at the surface and thus to avoid the formation of solid particles, the process is preferably carried out at reduced pressure.
[0034] Unlike the CVD, the starting material is converted into the gas phase using the preferred PVD. The gaseous material is then led to the substrate to be coated, where it condenses and forms the target layer. Examples are classical evaporation processes, such as thermal evaporation, electron beam (electron beam evaporation) or laser beam evaporation (pulsed laser deposition). For the purposes of the present invention, preferred is sputtering in which the starting material is sputtered by ion bombardment and transferred into the gas phase from which it can then be deposited on the basic body. All these processes have in common that the material to be deposited is in solid form in the mostly evacuated coating chamber. By bombardment with laser beams, magnetically deflected ions or electrons as well as by arc discharge, the target is evaporated. The proportion of atoms, ions or larger clusters in the vapor varies from procedure to procedure. The vaporized material moves either ballistically or performed by electric fields through the chamber and impinges on the parts to be coated, where it comes to the layer formation.
[0035] For achieving that the vapor particles reach the components, and are not lost by scattering at the gas particles, the work must be done in vacuum. Typical operating pressures are in the range of 10 −4 Pa to 10 Pa. Since the vapor particles propagate straight, areas that are not visible seen from the steam source, are coated with a lower deposition rate. In order to produce a relief and no homogeneous coating a rotation of the substrate will be omitted different from the usual procedure.
[0036] A fourth alternative embodiment of the relief formation comprises the so-called thermal spraying. Here additional materials, the so-called spray additives are melted off, at or on inside or outside a spray burner, accelerated in a gas stream in the form of spray particles and thrown on the surface of the component to be coated. The component surface in this case (in contrast to the cladding) is not melted and thermally loaded only slightly. A layer formation takes place, as the spray particles are flattening more or less depending on process and material when impinging on the component surface, stick primarily by mechanical bonding and layer by layer to build the spray layer. Quality characteristics of spray coatings are low porosity, easy bonding to the component, avoidance of cracks and homogeneous microstructure. The layer properties obtained are significantly influenced by the temperature and the speed of the spray particles at the time of incidence to the surface to be coated. The surface state (purity, activation temperature) also exerts a significant influence on quality characteristics such as adhesion.
[0037] As energy carrier for the melting of the spray additive material are used electric arc (arc spraying), plasma jet (plasma spraying), fuel-oxygen flame or fuel-oxygen high-speed flame (conventional and high-velocity flame spraying), fast, preheated gas (cold gas spraying) and laser beam (laser beam spraying). According to EN 657 DIN standard spray methods are classified according to these criteria.
[0038] Using this method, the base body may be coated not only with metals but also oxide-ceramic materials and carbide materials (or in general composites). Preferably in this embodiment the coating takes place with a steel/ceramic mixture.
[0039] While the base body is preferably made of steel, it is valid for the material forming the raised relief, the requirement that it is at least capable rata for forming an oxide layer. Preferably, this is iron or steel so that a layer of iron oxide, preferably scale is generated. It can be used as said, a mixture of iron/steel and ceramics for example in a weight ratio of about 20:80 to about 80:20.
[0040] It is understood that the relief may have different forms, ranging from regular (round, square, etc.) to any freeform. It can also be used composite materials, i.e. for example, a molybdenum fabric that is applied to the steel body. The fabric element can also consist of a composite of hard chrome steel (inside) and well oxidizable steel (outside). As the spacer, also combustible materials may be employed. It is also possible, for better heat insulation to embed ceramic.
[0041] Oxidation
[0042] The complete or partial conversion of the metallic reliefs in an oxidic protective layer may be produced by known methods of the prior art, for example by flame spraying, plasma spraying, or is carried out by a thermochemical process.
[0043] In the oxidation of the tool with the metallic body applied on its surface, for example a steel fabric, a part of the surface of the tool base body and a part of the relief deposited on the surface is converted into oxide. At the same time, an additional oxide layer is formed on all surfaces, typically to about 3000 microns, and especially about 1.500 to about 2,500 microns. Thus, also oxide is formed in the spaces between the bodies, for example, between the tool body and the applied steel fabric and within the meshes of the steel fabric. The result is a particularly thick protection layer which is reinforced by means of an internal body. In particular, the layer thickness is different than in the production of grooves not limited to a few millimeters. Layer thicknesses of 10 mm and more can be produced without difficulty and at low cost.
INDUSTRIAL APPLICABILITY
[0044] Another object of the invention relates to the use of the new tool described in detail above, especially as a piercing plug, forging mandrel or rolling mandrel for the production of seamless tubes or hot-forging tubular workpieces of metal.
EXAMPLES
Example 1
[0045] On the surface of a piercing plug a mesh preformed by forming the shape of the base steel was laid on with a steel wire thickness of 1.5 mm and a mesh width of 2.5 mm and welded. Successively, the composite has been exposed to a thermo-chemical oxidation. A coherent continuous oxide layer of 2500 microns thickness has been obtained.
[0046] FIG. 1 shows a hot forming tool in the form of a piercing plug in a side view. The tool 1 has a tool body 2 having a work area 3 , which extends in the direction of an axis A over a certain length. In the work area 3 , the tool is provided with a coating 4 which protects the tool 1 against thermal and mechanical stress.
[0047] FIGS. 2 and 3 show the detail “Z” in the horizontal section through the tool according to FIG. 1 once for the material body with raised relief before and after the production of the oxide protective layer (“scaling”).
[0048] In FIG. 2 a one recognizes the saw-shaped relief which is formed according to Example 1 by applying a wire mesh. In this case, the base body is characterized by the reference numeral 6 , the mesh by the numeral 7 . In FIG. 2 b it is seen that a part of the surface of the relief has been converted to oxide, but also between the loops of the mesh, the surface of the base body has been oxidized (hatching with reference numeral 8 ).
[0049] The FIGS. 3 a and 3 b are analogue, however, the relief here has no square, but a round cross section. Again, one can see that the oxide layer (hatching) is developing in equal proportions above and beneath the original surface of the ferrous body. | Disclosed is a hot forming tool ( 1 ) which consists of a main tool member ( 2 ) having an at least partial surface coating ( 4 ) and which can be obtained by providing the main tool member with a raised metal relief that is then entirely or partly oxidized and converted into a protective layer. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a signal transmission and reception device which performs communications by using impulse UWB (Ultra Wide Band) signals.
[0003] 2. Description of the Related Art
[0004] In spread spectrum communications, in order to obtain a large variety of correlation characteristics, it is proposed to convert Pseudorandom Noise (PN) codes used in DSSS (Direct Sequence Spread Spectrum) to Return-to-Zero (RZ) codes, and multiply the RZ codes by data. For example, Japanese Laid-Open Patent Application No. 4-347943 (referred to as “reference 1” hereinafter) discloses a technique in this field. Since each PN code can have a positive or a negative value, by converting the PN codes to the RZ codes, output data becomes zero in a certain time period of the PN code, thus, each RZ code can have three types of values, that is, a positive, zero, or a negative value.
[0005] On the other hand, a UWB-IR (UWB-Impulse Radio) communication system is attracting attention since the UWB-IR system is capable of large capacity data transmission and is able to accommodate a large number of users. Since impulses shorter than 1 ns are used in the UWB-IR system, and the corresponding frequency band is at a few GHz, conventional radio communications are not interfered with; thus the frequency band can be shared.
[0006] For example, it is proposed that a signal transmission device supporting the UWB-IR communications performs spread modulation and RZ conversion of the PN codes on data carried by the carrier, and converts the resulting data to impulse radio signals. Further, a signal reception device for receiving the impulse radio signals has been developed. For example, Japanese Laid-Open Patent Application No. 2006-114980 (referred to as “reference 2” hereinafter) discloses a technique in this field.
[0007] In addition to the capability of large capacity data transmission, when the UWB-IR communication system is used in data transmission, it is possible for the transmitter to measure positions with high precision. Further, when a receiver supporting the UWB-IR communications is used together with the transmitter, it is possible to measure distances with high precision.
SUMMARY OF THE INVENTION
[0008] It is a general object of the present invention to make some novel improvements.
[0009] One specific object of the present invention is to provide a compact signal transmission and reception device having a one-chip impulse receiver and a one-chip impulse transmitter, having low power consumption and capable of position and distance measurements, and data communications.
[0010] According to a first aspect of the present invention, there is provided a signal transmission and reception device, comprising:
[0011] a transmission unit that converts transmission data spread by spread codes to a RZ signal, multiplies a code of an impulse series by the RZ signal to convert the RZ signal to an impulse radio signal, and transmits the impulse radio signal, said transmission unit being integrated into one chip; and
[0012] a reception unit that receives and demodulates the impulse radio signal, said reception unit being integrated into one chip.
[0013] As an embodiment, a special position of the signal transmission and reception device may be determined when the signal transmission and reception device receives the impulse radio signal transmitted by the signal transmission and reception device itself.
[0014] As an embodiment, the signal transmission and reception device further comprises:
[0015] a distance measurement unit that measures a distance between the signal transmission and reception device and an object based on a time difference between an impulse radio signal transmitted by the transmission unit toward the object and an impulse radio signal reflected by the object and received by the reception unit.
[0016] As an embodiment, the signal transmission and reception device further comprises:
[0017] a filtering unit that passes through the impulse radio signal transmitted by the transmission unit and the impulse radio signal received by the reception unit,
[0018] wherein
[0019] the filtering unit includes
a first pass band for passing through an impulse radio signal for use of Ultra Wide Band communications, a second pass band different from the first pass band and for passing through an impulse radio signal for measuring the distance to the object, and
[0022] the filtering unit is able to switch the first pass band and the second pass band.
[0023] As an embodiment, the signal transmission and reception device further comprises:
[0024] an adjustment terminal that connects an adjustment device for adjusting electric power of the impulse radio signal transmitted by the transmission unit.
[0025] As an embodiment, the signal transmission and reception device further comprises:
[0026] a detection terminal that connects a detection device for detecting a level of the impulse radio signal received by the reception unit.
[0027] As an embodiment, in the signal transmission and reception device, a common clock signal is supplied to the transmission unit and the reception unit.
[0028] As an embodiment, in the signal transmission and reception device each of the transmission unit and the reception unit is formed of a CMOS or a silicon-germanium semiconductor.
[0029] As an embodiment, the signal transmission and reception device further comprises:
[0030] a switching unit that connects one of the transmission unit and the reception unit to a transmission and reception antenna; and
[0031] a controller that controls the switching unit.
[0032] As an embodiment, the signal transmission and reception device further comprises:
[0033] a sensor terminal that connects an external sensor; and
[0034] a converter that converts detection signals from the external sensor into digital signals.
[0035] According to the present invention, it is possible to provide a compact signal transmission and reception device having a one-chip impulse reception unit and a one-chip impulse transmission unit, having low power consumption and capable of position and distance measurements, and data communications.
[0036] These and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments given with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a block diagram illustrating a configuration of a signal transmission and reception device according to an embodiment of the present invention;
[0038] FIG. 2 is a flowchart illustrating switching a signal transmission procedure and a signal reception procedure in the signal transmission and reception device 1 of the present embodiment; and
[0039] FIG. 3 is a flowchart illustrating a procedure of distance measurement performed by the signal transmission and reception device 1 of the present embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Below, preferred embodiments of the present invention are explained with reference to the accompanying drawings.
[0041] FIG. 1 is a block diagram illustrating a configuration of a signal transmission and reception device according to an embodiment of the present invention.
[0042] As illustrated in FIG. 1 , a signal transmission and reception device 1 includes a transmitter 10 , a receiver 20 , a controller 30 , a switch 40 , an antenna 50 , and a power supplier 60 . Each of the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 is integrated into one chip by using CMOS (Complementary Metal Oxide Semiconductor).
[0043] The transmitter 10 includes a transmission base band processing unit 11 , an impulse converter 12 , an amplifier 13 , and a transmission filter 14 .
[0044] The receiver 20 includes a reception filter 21 , a low-noise amplifier (LNA) 22 , a detector (DET) 23 , and a reception base band processing unit 24 .
[0045] Each of the transmission filter 14 and the reception filter 21 includes a first pass band for passing through impulse radio signals used for Ultra Wide Band communication, and a second pass band for passing through impulse radio signals for distance measurement (as described below), and each of the transmission filter 14 and the reception filter 21 is able to switch the first pass band and the second pass band. For example, the first pass band is set at 4.5 GHz for Ultra Wide Band communications, and the second pass band is set at 1 GHz.
[0046] A common clock signal is supplied to the transmission base band processing unit 11 and the reception base band processing unit 24 . For example, as shown in FIG. 1 , a clock signal input to the transmission base band processing unit 11 via a clock terminal 15 is also input to the reception base band processing unit 24 .
[0047] The amplifier 13 is connected to an adjustment terminal 16 , which connects the amplifier 13 to an adjustment device for adjusting, from the outside, the electric power of the impulse radio signals to be transmitted.
[0048] The detector (DET) 23 is connected to a detection terminal 25 , which outputs a signal indicating strength of received impulse radio signals. This signal is referred to as a “RSSI (Received Signal Strength Indicator) signal” below, where necessary.
[0049] For example, the controller 30 includes a CPU (Central Processing Unit). The controller 30 is connected to an interface (I/F) 31 , a pulse input terminal 32 , an analog signal input terminal 33 (AIN), an Analog-Digital-Converter (A/D) 34 , and a flash memory terminal 35 .
[0050] For example, the interface (I/F) 31 is a serial peripheral interface (SPI). For example, when a USB (Universal serial Bus) memory is connected to the interface 31 , various kinds of data to be transmitted can be input to the signal transmission and reception device 1 .
[0051] For example, the pulse input terminal 32 is for inputting pulse signals used for distance measurement (as described below).
[0052] The analog signal input terminal 33 (AIN) is connected to an acceleration meter (not illustrated). An analog signal input from the acceleration meter through the analog signal input terminal 33 is converted into a digital signal, and is input to the transmitter 10 via the controller 30 .
[0053] The flash memory terminal 35 , for example, similar to the interface (I/F) 31 , also supports the serial peripheral interface (SPI). While the interface 31 is used for inputting transmission data, the flash memory terminal 35 is primarily used for inputting identification signals to the controller 30 . For example, the identification signals include identifiers for individual identification.
[0054] The controller 30 performs calculations for measuring the distance to an object based on a time difference between a transmitted wave and a received wave (namely, the delay time of the received wave relative to the transmitted wave).
[0055] The switch 40 , which is used for switching transmitted and received signals, is connected to an output terminal 10 A of the transmitter 10 , and an input terminal 20 A of the receiver 20 . Additionally, the switch 40 is connected to the antenna 50 , which is used for transmitting or receiving signals.
[0056] A power terminal 61 is provided on the signal transmission and reception device 1 for supplying power from the outside to the power supplier 60 .
[0057] Below, operations of the signal transmission and reception device 1 are described.
[0058] First, explanations are made when the signal transmission and reception device 1 is used in a position measurement system for measuring the special position of the signal transmission and reception device 1 .
[0059] For example, the position measurement system includes a calculation device, which performs position measurement processing for measuring the special position of the signal transmission and reception device 1 , and plural signal transmission and reception devices connected to the calculation device. Below, the plural signal transmission and reception devices are referred to as “nodes”. These nodes are arranged at positions allowing UWB communications with the signal transmission and reception device 1 . The signal transmission and reception device 1 is used as a tag, and is arranged in a space which is to be measured. Each of these nodes can be the same as the signal transmission and reception device 1 , and this allows radio communications between the nodes.
[0060] In the position measurement system, when impulse radio signals transmitted from the signal transmission and reception device 1 , which is used as a tag, are received by one of the nodes, the calculation device performs position measurement processing based on the position of the node which receives the impulse radio signals and the time of receiving the impulse radio signals by the node, and by this position measurement processing, the special position of the signal transmission and reception device 1 can be determined with high precision.
[0061] Specifically, when the controller 30 directs to turn the transmitter 10 ON, the transmission base band processing unit 11 encodes and compresses digital data used for position measurement by known appropriate methods, and outputs the encoded and compressed data to the impulse converter 12 . The impulse converter 12 modulates the compressed data from the transmission base band processing unit 11 , for example, by phase modulation or others, and then, the modulated data are further modulated by spread modulation by using the PN (Pseudorandom Noise) codes. Further, the impulse converter 12 converts the data modulated by spread modulation to RZ signals, and the RZ signals are converted into impulse radio signals. At this stage, since the transmitter 10 and the antenna 50 are connected through the switch 40 controlled by the controller 30 , the output signals from the impulse converter 12 are amplified by the amplifier 13 to a certain level, and are transmitted from the antenna 50 through the transmission filter 14 .
[0062] When the impulse radio signals transmitted from the antenna 50 of the signal transmission and reception device 1 are received by one of the nodes of the position measurement system, and the above position measurement processing is executed, the special position of the signal transmission and reception device 1 can be determined with high precision.
[0063] When the controller 30 directs to turn the receiver 20 ON, the switch 40 is switched to the receiver 20 side, and the signal transmission and reception device 1 is ready for receiving data from the node.
[0064] When the receiver 20 receives the impulse radio signals from the node, the signal transmission and reception device 1 determines whether the received impulse radio signals are those sent to itself.
[0065] FIG. 2 is a flowchart illustrating switching of a signal transmission procedure and a signal reception procedure in the signal transmission and reception device 1 of the present embodiment.
[0066] Note that the procedure shown in FIG. 2 can be executed by the transmitter 10 , the receiver 20 , and the controller 30 .
[0067] As shown in FIG. 2 , in step S 20 , the controller 30 switches the switch 40 in each specified time period to determine whether the impulse radio signals are received.
[0068] In this way, impulse radio signals involved in the determination by the controller 30 are signals transmitted from a node of the position measurement system. When the receiver 20 receives the impulse radio signals, the receiver 20 demodulates the received impulse radio signals, and transmits the demodulated data to the controller 30 .
[0069] When it is determined that the impulse radio signals are not received, the procedure proceeds to step S 21 .
[0070] In step S 21 , the switch 40 is switched to the transmitter 10 side.
[0071] In step S 22 , the transmitter 10 encodes and compresses the transmission data by appropriate coding methods. In this step, the base band is modulated by the transmission base band processing unit 11 .
[0072] In step S 23 , the transmitter 10 performs spread modulation and RZ conversion by using the PN (Pseudorandom Noise) codes, and the RZ signals are converted into impulse radio signals. In this way, the impulse radio signals are produced.
[0073] In step S 24 , the impulse radio signals are transmitted from the antenna 50 .
[0074] In step S 25 , when it is determined by the controller 30 in step S 20 that the impulse radio signals are received, base band demodulation is performed on the received impulse radio signals.
[0075] In step S 26 , the controller 30 confirms the identifier included in the demodulated signals.
[0076] In step S 27 , when the controller 30 determines that the identifier included in the demodulated signals is the same as the identifier of the signal transmission and reception device 1 , the controller 30 reads in the received data, and performs processing according to the received data.
[0077] Concerning the impulse radio signals transmitted from the position measurement system and received by the receiver 20 , for example, when plural signal transmission and reception devices 1 are present in a certain space, the impulse radio signals may be signals including data for ranking the signal transmission and reception devices 1 . Due to this, since plural signal transmission and reception devices 1 can be ranked in the position measurement system to perform data communications sequentially, data for performing calling out and standby can be transmitted to the signal transmission and reception devices 1 .
[0078] Signals indicating data requested by the signal transmission and reception device 1 can be transmitted from the position measurement system to the signal transmission and reception device 1 . Due to this, when the signal transmission and reception device 1 is used in the position measurement system, it is possible to construct a network system.
[0079] If an acceleration meter is connected to the analog signal input terminal 33 of the signal transmission and reception device 1 , and acceleration data detected by the acceleration meter are sent to the position measurement system, the position measurement system is able to determine the position of the signal transmission and reception device 1 . Furthermore, the position measurement system can receive acceleration data detected by the acceleration meter connected to the signal transmission and reception device 1 .
[0080] FIG. 3 is a flowchart illustrating a procedure of distance measurement performed by the signal transmission and reception device 1 of the present embodiment.
[0081] As described above, the signal transmission and reception device 1 is able to transmit or receive the impulse radio signals. If the signal transmission and reception device 1 is configured to receive impulse radio signals transmitted by itself toward a specified target, the distance from the signal transmission and reception device 1 to the target can be measured. For example, the controller 30 performs calculations and processing required for the distance measurement.
[0082] As shown in FIG. 3 , in step S 30 , the controller 30 switches the switch 40 to the transmitter side.
[0083] In step S 31 , the transmitter 10 generates impulse radio signals based on pulse signals from the controller 30 . For example, the pulse signals are input from a pulse generator (not illustrated) connected to the pulse input terminal 32 and are used for distance measurement. At the stage, the pass band of the transmission filter 14 may be switched to the second pass band to transmit impulse radio signals at 1 GHz.
[0084] In step S 32 , the controller 30 switches the switch 40 to the side of the receiver 20 .
[0085] In step S 33 , the receiver 20 demodulates the received impulse radio signals.
[0086] In step S 34 , it is determined whether the transmitted impulse radio signals and the received impulse radio signals are sufficiently strongly correlated to each other. For example, this determination can be executed by sliding correlation.
[0087] In step S 35 , when it is determined that sufficiently strong correlation exists, the controller 30 calculates the time delay between the transmitted impulse radio signals and the received impulse radio signals.
[0088] In step S 36 , the controller 30 calculates the distance to the target based on obtained time delay.
[0089] When it is determined that sufficiently strong correlation does not exist, the controller 30 returns to step S 30 .
[0090] In this way, the distance to the target can be obtained by the signal transmission and reception device 1 of the present embodiment.
[0091] If the signal transmission and reception device 1 is used outside, it can be used in a radar device to realize various applications. That is, the place for using the signal transmission and reception device 1 is not limited to the above mentioned desired space where the position measurement system is installed.
[0092] According to the present embodiment, it is possible to provide a compact signal transmission and reception device formed from a one-chip impulse receiver 20 and a one-chip impulse transmitter 10 , having low power consumption and capable of position and distance measurements, and data communications.
[0093] While the invention is described above with reference to specific embodiments chosen for purpose of illustration, it should be apparent that the invention is not limited to these embodiments, but numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
[0094] For example, it is described above that each of the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 is integrated into one chip by using CMOS (Complementary Metal Oxide Semiconductor), but the present invention is not limited to this. Instead of CMOS, the transmitter 10 , the receiver 20 , the controller 30 , the switch 40 , and the power supplier 60 can be integrated into one chip by using silicon-germanium semiconductor.
[0095] It is described above that the transmitter 10 and the receiver 20 have built-in transmission filter 14 and reception filter 21 , respectively, but the present invention is not limited to this. The transmission filter 14 and reception filter 21 can be provided outside the signal transmission and reception device 1 .
[0096] It is described above that the switch 40 switches the connection between the transmitter 10 and the receiver 20 with the antenna 50 , but the present invention is not limited to this. For example, the transmitter 10 and the receiver 20 may have their own antennae, respectively. In this case, the switch 40 can be omitted.
[0097] It is described above that the first pass band of the transmission filter 14 and reception filter 21 is set at 4.5 GHz, but the present invention is not limited to this. The first pass band can be set to be any value in a range from 3.1 to 10.6 GHz as long as the first pass band is a band allowing Ultra Wide Band communications.
[0098] In addition, when the signal transmission and reception device 1 does not measure the distance but only performs Ultra Wide Band communications, the transmission filter 14 and reception filter 21 may be omitted.
[0099] It is described above that the switch 40 is installed in the signal transmission and reception device 1 , but the present invention is not limited to this. The switch 40 may be provided outside the signal transmission and reception device 1 .
[0100] It is described above that an acceleration meter is connected to the analog signal input terminal 33 , but the present invention is not limited to this. Various sensors can be connected to the analog signal input terminal 33 , for example, when a sensor for detecting vital signs like blood pressure and pulsation, the vital data of the owner of the signal transmission and reception device 1 can be transmitted.
[0101] This patent application is based on Japanese Priority Patent Application No. 2007-051827 filed on Mar. 1, 2007, the entire contents of which are hereby incorporated by reference. | A signal transmission and reception device is disclosed that can be made compact and has wide-band band-pass characteristics. The signal transmission and reception device includes a first filtering unit that is composed of a distributed constant circuit and is capable of eliminating a first frequency component or a second frequency component. The second frequency is higher than the first frequency, and a second filtering unit that attenuates components of frequencies lower than the first frequency or components of frequencies higher than the second frequency. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority from Japanese patent application 325529/2001, filed in Japan on Oct. 23, 2001.
FIELD OF THE INVENTION
This invention relates to a plastic movable guide for a power transmission in which an endless chain transmits power from a driving sprocket to a driven sprocket or an endless belt transmits power from a driving pulley to a driven pulley. The guide may be used, for example, as a fixed guide, or as a pivotally mounted tensioner lever.
BACKGROUND OF THE INVENTION
Many engines, and other machines in which mechanical power is transmitted from one shaft to another, include a circulating transmission device, comprising a chain, a belt, or the like as shown in FIG. 10. A movable guide Ga, on which the transmission medium C slides, may be used, in cooperation with a tensioner T, to impart appropriate tension to the transmission medium, and also to prevent vibration in the plane of circulation of the transmission medium and also transverse vibration. The movable guide Ga is ordinarily attached to a frame E of the engine or other machine by a supporting shaft P, which may be a mounting bolt, a pin, or the like. In FIG. 10, an endless, circulating transmission medium is engaged with a driving sprocket S 1 , driven sprockets S 2 , and a fixed guide Gb for guiding, and limiting the traveling path of, the circulating transmitting medium C.
FIGS. 8 and 9 show a plastic movable guide 300 , used as a tensioner lever in a transmission device utilizing a chain, as described in present inventors' previously filed Japanese Patent Application No. 2000-382798.
In this plastic movable guide 300 , a guide body 301 includes a shoe 302 . A transmitting medium C, such as a traveling chain, belt or the like, is in sliding contact with a surface of the shoe. A plate-receiving portion 303 , provided on the back of the shoe 302 , and extending along the longitudinal direction of the guide, is molded of synthetic resin as a unit with the shoe. A reinforcing plate 308 , composed of a rigid material which reinforces the guide body 301 , fits into a slot 307 , which opens in an edge of the plate-receiving portion 303 along the longitudinal direction of the guide, and faces in a direction opposite to the direction in which the chain-engaging surface of the shoe faces. A mounting hole 305 , for mounting on the frame of an engine, or other machine, is provided at a fixed end of the plate-receiving portion 303 . A through hole 308 A is also provided at one end of the reinforcing plate 308 . The through hole is positioned and fastened, together with the mounting hole 305 in the guide body 301 , on a shaft such as a mounting bolt or the like, with the reinforcing plate 308 fitting into the slot 307 .
In the above-described plastic movable guide 300 , the shoe 302 and the plate-receiving portion 303 are integrally molded as a unit from a synthetic resin. The guide body 301 itself performs a sliding function, and it is not necessary to provide a separate shoe member. Therefore, the number of the parts and the number of production steps is minimized. Furthermore, since a slot 307 opens at an edge of the plate-receiving portion 303 in the guide body 301 along the longitudinal direction of the guide, and the reinforcing plate 308 fits into the slot 307 , the strength of the plastic movable guide in the pivoting direction is increased, and its bending rigidity, toughness, strength are significantly improved.
A mounting hole, for mounting the guide on a frame of an engine, a drive, or the like, is provided adjacent a fixed end of the guide body, and a through hole, which is positioned in register with the mounting hole of guide body, is provided adjacent one end of the reinforcing plate, so that the guide body and reinforcing plate can be fastened together on a supporting shaft, such as a mounting bolt, pin, or the like, which extends through both holes. Thus, both the guide body and the reinforcing plate can be pivotally rotated about a mounting axis while cooperating with each other without the reinforcing plate becoming disassembled from the guide body. Furthermore, since the reinforcing plate is only connected to the guide body by the supporting shaft adjacent one end of the reinforcing plate, and fits into the slot of the guide body, even if there is a difference between the coefficients of thermal expansion of the guide body and the reinforcing plate, the reinforcing plate and guide body are free to move relative to each other in the longitudinal direction of the guide, and thermal shape deformation and resulting breakage are avoided.
In the conventional plastic movable guide 300 , the relationships between the respective sizes and shapes of the mounting hole 305 bored in the guide body 301 and the through hole 308 A bored in the reinforcing plate 308 , are not considered, and the diameter of the mounting hole 305 is set to be the same as that of the through hole 308 A by design. However, a variation in working accuracy in production, and a difference between the coefficients of thermal expansion of the materials made the diameter of the hole 308 A in the reinforcing plate smaller than the diameter of the hole 305 in the guide body, causing the edge of the through hole 308 A to protrude inward past the inner periphery of the hole 305 .
When the conventional plastic movable guide is attached to the frame of an engine and used as a tensioner lever, objectionable metallic noise and transverse vibration are generated, both exceeding the noise and vibration generated when a plastic movable guide composed only of resin was used. A solution to these problems is desirable in view of requirements for reduced engine noise.
Furthermore, in the conventional plastic movable guide, the reinforcing plate can seize on its supporting shaft due to friction. Friction between the reinforcing plate and its supporting shaft can also cause wear, generating metal powder, the presence of which inside an engine can lead to engine failure. Thus, it has been necessary to subject the reinforcing plate to a preliminary strengthening process such as heat treatment in order to enhance its wear resistance. The necessity of preliminary treatment results in an increase in production cost. Furthermore, subjecting the reinforcing plate to a strengthening process such as heat treatment or the like, causes distortion of the reinforcing plate, impairing the ability of the reinforcing plate to fit easily into the slot of the guide body, and potentially reducing assembly efficiency. Thus, improvements are also desirable to avoid seizing, wear, increased production cost and reduced efficiency of assembly.
The inventors have studied and analyzed the causes of metallic noise generation, transverse vibration, wear of the reinforcing plate and seizing of the plate on its supporting shaft. As a result of their studies, the inventors have unexpectedly found that these problems do not occur in all plastic movable guides, but occur only where the diameter of the through hole bored in the reinforcing plate is smaller than that of the mounting hole bored in the guide body, or in where a part of the inner periphery of the through hole in the reinforcing plate protrudes inwardly past the inner periphery of the mounting hole in the guide body. Thus, the inventors have determined that the above-mentioned problems result from direct contact between the support shaft, that is the mounting bolt, pin, or the like, and the inner periphery of the through hole bored in the reinforcing plate.
Accordingly, the objects of the invention are to solve the above-mentioned problems encountered in the production and use of prior art plastic movable guides, and to provide a plastic movable guide having excellent quietness, improved assembly efficiency, and reduced production cost.
SUMMARY OF THE INVENTION
The guide in accordance with the invention comprises an elongated guide body composed of an elongated shoe having a front surface for sliding contact with a power transmission medium and a back side. A plate-receiving portion extends longitudinally along the back side of the shoe and has a longitudinally extending slot open in a direction opposite to the direction in which the front surface of the shoe faces. The shoe and plate-receiving portion are integrally molded as a unit from a synthetic resin. A reinforcing plate fits into the slot.
The guide body has a mounting hole adjacent one end thereof, and the reinforcing plate has a through hole adjacent one of its ends. When the reinforcing plate is seated in the slot, the elongated mounting hole and the through hole are substantially coaxial with each other so that an attachment means, inserted through the mounting and through holes, can support the guide body and reinforcing plate on a frame of an engine. The structure is characterized by the fact that the diameter of the through hole in the reinforcing plate is greater than the diameter of the mounting hole in the guide body.
In a preferred embodiment, a locking means is provided for positioning and locking the through hole and the mounting hole in coaxial relationship.
The resin material forming the guide body is not especially limited. However, since the contact sliding surface of the guide body with a chain, a belt, or the like functions as a shoe, the material is preferably a so-called “engineering plastic,” such as a polyamide type resin having high wear resistance and good lubricating properties. A fiber-reinforced resin may be used for the entire guide body, or may be used concurrently another plastic material. The material of the reinforcing plate is also not especially limited, but the reinforcing plate must have sufficient bending rigidity and strength to function effectively as a reinforcement for the plastic movable guide. Iron-based metals such as cast iron, stainless steel and the like, nonferrous metals such as aluminum, magnesium, titanium and the like, engineering plastics such as polyamide type resin and the like, and fiber reinforced plastics are preferably used as materials for the reinforcing plate.
The plastic movable transmission guide according to the invention, having the above-described configuration, exhibits the following unique effects.
First, because the diameter of the through hole bored in the reinforcing plate is larger than that of the mounting hole of the guide body, the through hole and the mounting hole may be fastened together on a shaft such as a mounting bolt or the like. When the guide is mounted on the shaft, the shaft is engaged with the inner surfaces of a pair of opposed parts of the mounting hole of the guide body, but does not contact the inner periphery of the through hole bored in the reinforcing plate. Therefore, the occurrence of objectionable metallic noise and wear of the reinforcing plate are avoided. Further, since the shaft support means is supported by the inner walls of parts of the mounting hole on both sides of the reinforcing plate, transverse vibration is significantly reduced.
If the through hole bored in the reinforcing plate and the mounting hole bored in the guide body are positioned and locked so that they are on the same axis, even if the guide is subjected to excessive vibration, deformation of the reinforcing plate is prevented, and contact of the inner periphery of the through hole with the supporting shaft can be reliably avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a movable guide, in accordance with a first embodiment of the invention;
FIG. 2 is a bottom plan view of the guide body shown in FIG. 1;
FIG. 3 is an exploded cross-sectional view taken on surface III—III in FIG. 1;
FIG. 4 is a cross-sectional view taken on surface III—III in FIG. 1, showing the guide body and reinforcing plate in an assembled condition;
FIG. 5 is a cross-sectional view taken on surface V—V in FIG. 1;
FIG. 6 is an exploded view of a movable guide, in accordance with a second embodiment of the invention;
FIG. 7 ( a ) is a cross-sectional view taken on plane VII—VII in FIG. 6;
FIG. 7 ( b ) is an enlarged view of a portion designated “VII B ” in FIG. 7 ( a );
FIG. 8 is an exploded view of a conventional movable guide;
FIG. 9 is a bottom plan view of the conventional movable guide in FIG. 8; and
FIG. 10 is a schematic view showing the guide as used in the timing transmission of an engine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the invention will be described with reference to FIGS. 1 to 5 . As shown in FIG. 1, a movable guide 100 is formed by incorporating a reinforcing plate 108 into a guide body 101 in the direction of the arrow.
The guide body 100 is a plastic body integrally molded as a unit from a synthetic resin, and comprises a shoe 102 having, on one side, a surface for sliding contact with a chain, and having, on its opposite side, a plate-receiving portion 103 extending longitudinally along the length of the guide. A flange 104 is formed at an edge of the plate-receiving portion 103 along the longitudinal direction of the guide, and a boss portion 106 is formed adjacent one end of the guide. The boss has a mounting hole 105 for pivotally mounting the guide on a frame of an engine, drive mechanism or the like by means of a supporting shaft such as a mounting bolt or the like.
A truss-shaped arrangement of reinforcing ribs 103 ′ is formed on a side portion of the plate-receiving portion 103 . A slot 107 extends along the longitudinal direction of the guide. The opening of the slot is in flange 104 and faces in the direction opposite to the direction in which the chain-contacting surface of the shoe faces, as can be seen from FIGS. 3 to 5 . To reinforce the guide body 101 , a reinforcing plate 108 , made of a rigid material, is fitted into the slot 107 from the side opposite the side on which the shoe 102 is formed.
As shown in FIG. 1 and FIG. 3, a through hole 108 A, having a diameter d 1 larger than diameter d 2 of the mounting hole 105 , is bored in the reinforcing plate 108 at a position such that, when the plate is inserted into the slot 107 , the center axis of the through hole 108 A coincides with the center axis of the mounting hole 105 of the guide body 101 .
The diameter d 1 of the through hole may exceed the diameter d 2 of the mounting hole to any degree provided that the through hole 108 A can be reliably supported by the inner wall of the mounting hole 105 without contact between the shaft support means 109 and the inner periphery of the through hole 108 A. In this example, the through hole and the mounting hole each have a circular shape. However, so long as the inner periphery of the through hole does not extend inward past the edge of the mounting hole, that is, so long as an axial projection of the mounting hole is entirely within the boundary of the through hole in the reinforcing plate when the guide body and the reinforcing plate are in the assembled condition, the shape of the through hole 108 A may be varied. For example, an elongated hole, or an oval hole having different lengths in the vertical and horizontal directions, may be used. For optimum efficiency in the assembly of the guide in which the through hole in the reinforcing plate is an elongated or oval hole, it is desirable to bore the through hole so its long dimension extends in the direction of insertion of the reinforcing plate, as shown in FIG. 1 . The shorter dimension of the elongated or oval hole must, of course, be greater than the diameter of the mounting hole in guide body.
The plastic movable guide, into which the reinforcing plate 108 is inserted, may be mounted on a frame of an engine, a drive mechanism or the like, by means of a shoulder bolt 109 , having a pivot support portion 109 A as shown in FIG. 3, or a mounting pin provided on the frame. The guide body 101 and the reinforcing plate 108 are penetrated by the bolt or pin, and fastened together with each other.
In this case, since the through hole 108 A is on the same center axis with the mounting hole 105 of the guide body 101 , and the reinforcing plate 108 is fastened and supported by a shaft support means 109 such as a mounting bolt, mounting pin, or the like, even if there is a difference between the coefficients of thermal expansion of the guide body 101 and the reinforcing plate 108 , both the guide body 101 and the reinforcing plate 108 are free to expand and contract relative to each other in the longitudinal direction of the guide. Thus, shape deformation due to thermal expansion or the like is avoided, and no breakage occurs.
A locking means (not shown in FIGS. 3 and 4) for positioning and locking the through hole 108 A and the mounting hole 105 together on the same center axis, is provided, near the boss portion 106 , on a plane where the reinforcing plate 108 and the guide body 101 are opposed to each other. By way of example, the locking means comprise mutually engageable projections and depressions, or may comprise a hole and a hook, or the like. An example of a locking means is illustrated, and described below, in connection with a second embodiment of the invention.
When the reinforcing plate is inserted and fitted into the slot 107 of the guide body 101 , the provision of such a locking means allows the through hole 108 A and the mounting hole 105 to be positioned on the same center axis. Even when extreme vibration is applied to the guide body 101 and the reinforcing plate 108 during use, the locking means reliably prevents contact between the supporting shaft and the inner periphery of the through hole 108 A for a long period of time, so that the center axes of the through hole 108 A and the mounting hole 105 do not shift relative to each other.
A second-embodiment of the invention will be described with reference to FIGS. 6, 7 ( a ) and 7 ( b ). As shown in FIG. 6, a plastic movable guide 200 is formed by inserting a reinforcing plate 208 into a guide body 201 in the direction of the arrow.
Reinforcing ribs 203 ′ are provided on the exterior of a plate-receiving portion 203 so that they extend in a substantially perpendicular direction with respect to a shoe 202 . However, the shapes of the reinforcing ribs may be appropriately selected in consideration of requirements of strength and moldability. To reduce the overall weight of the guide, through holes 208 B are punched in the reinforcing plate 208 .
In the example shown in FIGS. 6, 7 ( a ) and 7 ( b ), the through hole is elongated or oval in shape, having its long dimension d 3 in the direction in which the reinforcing plate is inserted into the slot in the guide body. Dimension d 3 is longer than the dimension d 5 in the direction of elongation of the guide. With this dimensional relationship, positioning of the reinforcing plate 208 in the guide body 201 becomes easy, resulting in improved assembly efficiency.
As shown in FIGS. 7 ( a ) and 7 ( b ), a projection 208 C is formed on a face of reinforcing plate 208 adjacent the through hole. This projection fits into a depression 207 A formed on one of the inner walls of the slot adjacent the mounting hole in the plate-receiving portion 203 of the guide body 201 . The projection 208 C snaps into the depression 207 A when the reinforcing plate is inserted into the slot of the guide body. The depression is provided at a position such that, when the projection and depression are engaged with each other, the center axis of the through hole and the center axis of the mounting hole coincide. In this way, the through hole of the guide is properly positioned in relation to the mounting hole of the guide body so that the inner periphery of the through hole cannot contact the mounting bolt. Various alternative locking schemes can be used. For example one or more projections can be formed on the inner wall of the slot for engagement with depressions formed in the reinforcing plate. Another example of a locking device is a hook (not shown) formed on, and projecting from the end of the reinforcing plate, for engagement with a hole formed in an end wall of the slot, the hook engaging the hole by a slight clockwise rotation of the reinforcing plate as it is inserted into the slot in the direction of the arrow of FIG. 6 .
The more important advantages of the invention may be summarized as follows.
Since the diameter of the through hole bored in the reinforcing plate is larger than that of the mounting hole in the guide body, when the reinforcing plate is situated in the slot of the guide body and guide is supported on a shaft extending through the holes of both parts, the shaft is not contacted by the inner periphery of the reinforcing plate. Consequently objectionable metallic noise is avoided, and the noise due to the pivoting motion of the guide is remarkably reduced. Furthermore, wear in the through hole portion of the reinforcing plate is avoided, so that it is not necessary to subject the reinforcing plate to a strengthening process such as heat treatment or the like. Consequently, the production cost of the guide can be reduced. Additionally, distortion due to heat treatment and the like is also avoided and efficient insertion of the reinforcing plate into the slot of the movable guide in the assembly process is also improved. Since the shaft supports the inner walls of the two parts of the mounting hole, transverse vibration due to pivoting of the movable guide can also be significantly reduced.
When locking means are provided, the through hole bored in the reinforcing plate and the mounting hole bored in the guide body can be easily positioned so that they are on the same center axis. Thus, the assembly efficiency of the guide body and the reinforcing plate may be further enhanced, and the through hole and the mounting hole can be reliably locked in the proper position. Accordingly, even if excessive vibration has been applied to the movable guide, deformation of the reinforcing plate inserted into the guide body is prevented and the contact between the inner wall of the through hole in the reinforcing plate and the support shaft can be reliably avoided over a long period of time. | A plastic movable guide for a chain or other traveling transmission medium, comprises a guide body composed of a shoe and a slotted plate-receiving portion integrally molded as a unit from a resin, and a reinforcing plate inserted into the slot. A mounting hole adjacent one end of the guide body is aligned with a hole adjacent one end of the reinforcing plate. The diameter of the hole in the reinforcing plate is larger than the diameter of the mounting hole in the guide body, so that the inner periphery of the hole in the reinforcing plate does not extend inward past the edge of the mounting hole. The guide so configured exhibits excellent quietness and assembly efficiency and can be produced at a relatively low cost. | 5 |
FIELD OF INVENTION
The present invention relates to 2-indolinone derivatives which are capable of inhibiting protein kinases and histone deacetylases. The compounds of this invention are therefore useful in treating diseases associated with abnormal protein kinase activities or abnormal histone deacetylase activities. Pharmaceutical compositions comprising these compounds, methods of treating diseases utilizing pharmaceutical compositions comprising these compounds, and methods of preparing these compounds are also disclosed.
BACKGROUND OF THE INVENTION
The favorite metaphor for cancer drug developers has long been target therapy, wherein a drug is designed to hit tumor cells at one specific target, knocking them out while leaving normal cells undamaged. Cancer cells, however, can use multiple biological triggers and pathways to grow and spread throughout the body. Hitting cancer cells at one target will allow them to regroup and redeploy along new growth paths. This realization has led to the development of combination target therapies, which are becoming the new paradigm for cancer treatment.
Several multi-target kinase inhibitors are now in development, two, (Sorafenib and Suten) are already approved in the United States. Sorafenib, developed by Bayer Pharmaceuticals, is the first drug targeting both the RAF/MEK/ERK pathway (involved in cell proliferation) and the VEGFR2/PDGFRβ signaling cascade (involved in angiogenesis). Sorafenib was first approved in December 2005 for advanced kidney cancer, a disease that is believed to be highly dependent on angiogenesis. Although some of these target therapies have been found to be effective against solid tumors, they remain far from satisfactory in terms of achieving better efficacy and minimizing treatment side-effects. Thus, the search for target therapies continues. One option is develop agents that inhibit protein kinsases as well as histone deacetylases.
Protein kinases are a family of enzymes that catalyze the phosphorylation of proteins, in particular the hydroxy group of specific tyrosine, serine and threonine residues in proteins. Protein kinases play a critical role in the regulation of a wide variety of cellular processes, including metabolism, cell proliferation, cell differentiation, cell survival, environment-host reactions, immune responses, and angiogenesis. Many diseases are associated with abnormal cellular responses triggered by protein kinase—mediated events. These diseases include inflammatory diseases, autoimmune diseases, cancer, neurological and neurodegenerative diseases, cardiovascular diseases, allergies and asthma or hormone-related disease (Tan, S-L., 2006, J. Immunol., 176: 2872-2879; Healy, A. ea al., 2006, J. Immunol., 177: 1886-1893; Salek-Ardakani, S. et al., 2005, J. Immunol., 175: 7635-7641; Kim, J. et al., 2004, J. Clin. Invest., 114: 823-827). Therefore, considerable effort has been made to identify protein kinase inhibitors that are effective as therapeutic agents against these diseases.
The protein kinases can be conventionally divided into two classes, the protein tyrosine kinases (PTKs) and the serine-threonine kinases (STKs).
The protein tyrosine kinases (PTKs) are divided into two classes: the non-transmembrane tyrosine kinases and transmembrane growth factor receptor tyrosine kinases (RTKs). At present, at least nineteen distinct subfamilies of RTKs have been identified, such as the epidermal growth factor receptor (EGFR), the vascular endothelial growth factor receptor (VEGFR), the platelet derived growth factor receptor growth factor receptor (PDGFR), and the fibroblast growth factor receptor (FGFR).
The epidermal growth factor receptor (EGFR) family comprises four transmembrane tyrosine kinase growth factor receptors: HER1, HER2, HER3 and HER4. Binding of a specific set of ligands to the receptor promotes EGFR dimerization and results in the receptors autophosphorylation on tyrosine residues (Arteaga, C-L., 2001, Curr. Opin. Oncol., 6: 491-498). Upon autophosphorylation of the receptor several signal transduction pathways downstream of EGFR become activated. The EGFR signal transduction pathways have been implicated in the regulation of various neoplastic processes, including cell cycle progression, inhibition of apoptosis, tumor cell motility, invasion and metastasis. EGFR activation also stimulates vascular endothelial growth factor (VEGF), which is the primary inducer of angiogenesis (Petit, A-M. et al., 1997, Am. J. Pathol., 151: 1523-1530). In experimental models, deregulation of the EGFR-mediated signal transduction pathways is associated with oncogenesis (Wikstrand, C-J. et al., 1998, J Natl Cancer Inst., 90: 799-800). Mutations leading to continuous activation of amplification and over expression of EGFR proteins are seen in many human tumors, including tumors of breast, lung, ovaries and kidney. These mutations are a determinant of tumor aggressiveness (Wikstrand, C-J. et al., 1998, J Natl Cancer Inst., 90: 799-800). EGFR over expression is frequently seen in non-small cell lung cancer (NSCLC). Activity of EGFR can be inhibited either by blocking the extracellular ligand binding domain with the use of anti-EGFR antibodies or by the use of small molecules that inhibit the EGFR tyrosine kinase, thus resulting in inhibition of downstream components of the EGFR pathway (Mendelsohn, J., 1997, Clin. Can. Res., 3: 2707-2707).
The vascular endothelial growth factor (VEGF) is secreted by almost all solid tumors and tumor associated stroma in response to hypoxia. It is highly specific for vascular endothelium and regulates both vascular proliferation and permeability. Excessive expression of VEGF levels correlate with increased microvascular density, cancer recurrence and decreased survival (Parikh, A-A., 2004;, Hematol. Oncol. Clin. N. Am., 18:951-971). There are 6 different ligands for the VEGF receptor, VEGF-A through -E and placenta growth factor. Ligands bind to specific receptors on endothelial cells, mostly VEGFR-2. The binding of VEGF-A to VEGFR-1 induces endothelial cell migration. Binding to VEGFR-2 induces endothelial cell proliferation, permeability and survival. VEGFR-3 is thought to mediate lymphangiogenesis. The binding of VEGF to VEGFR-2 receptors results in activation and autophosphorylation of intracellular tyrosine kinase domains which further triggers other intracellular signaling cascades (Parikh, A-A., 2004, Hematol. Oncol. Clin. N. Am., 18:951-971).
The serine-threonine kinases (STKs) are predominantly intracellular although there are a few receptor kinases of the STK type. STKs are the most common forms of the cytosolic kinases that perform their function in the part of the cytoplasm other than the cytoplasmic organelles and cytoskelton.
Glycogen synthase kinase-3 (GSK-3) is a serine-threonine protein kinase comprised of α and β isoforms that are each encoded by distinct genes. GSK-3 has been found to phosphorylate and modulate the activity of a number of regulatory proteins. GSK-3 has been implicated in various diseases including diabetes, Alzheimer's disease, CNS disorders such as manic depressive disorder and neurodegenerative diseases, and cardiomyocyte hypertrophy (Haq, et al., 2000, J. Cell Biol., 151: 117).
Aurora-2 is a serine-threonine protein kinase that has been implicated in human cancer, such as colon, breast, and other solid tumors. This kinase is believed to be involved in protein phosphorylation events that regulate cell cycle. Specifically, Aurora-2 may play a role in controlling the accurate segregation of chromosomes during mitosis. Misregulation of the cell cycle can lead to cellular proliferation and other abnormalities. In human colon cancer tissue, the Aurora-2 protein has been found to be over expressed (Schumacher, et al., 1998, J. Cell Biol., 143: 1635-1646; Kimura et al., 1997, J. Biol. Chem., 272: 13766-13771).
The cyclin-dependent kinases (CDKs) are serine-threonine protein kinase that regulate mammalian cell division. CDKs play a key role in regulating cell machinery. To date, nine kinase subunits (CDK 1-9) have been identified. Each kinase associates with a specific regulatory partner which together make up the active catalytic moiety. Uncontrolled proliferation is a hallmark of cancer cells, and misregulation of CDK function occurs with high frequency in many important solid tumors. CDK2 and CDK4 are of particular interest because their activities are frequently misregulated in a wide variety of human cancers.
Raf kinase, a downstream effector of ras oncoprotein, is a key mediator of signal-transduction pathways from cell surface to the cell nucleus. Inhibition of raf kinase has been correlated in vitro and in vivo with inhibition of the growth of variety of human tumor types (Monia et al., 1996, Nat. Med., 2: 668-675).
Other serine-threonine protein kinases include the protein kinase A, B and C. These kinases, known as PKA, PKB and PKC, play key roles in signal transduction pathways.
Many attempts have been made to identify small molecules which act as protein kinase inhibitors useful in the treatment of diseases associated with abnormal protein kinase activities. For example, cyclic compounds (U.S. Pat. No. 7,151,096), bicyclic compounds (U.S. Pat. No. 7,189,721), tricyclic compounds (U.S. Pat. No. 7,132,533), (2-oxindol-3-ylidenyl) acetic acid derivatives (U.S. Pat. No. 7,214,700), 3-(4-amidopyrrol-2-ylmethlidene)-2-indolinone derivatives (U.S. Pat. No. 7,179,910), fused pyrazole derivatives (U.S. Pat. No. 7,166,597), aminofurazan compounds (U.S. Pat. No. 7,157,476), pyrrole substituted 2-indolinone compounds (U.S. Pat. No. 7,125,905), triazole compounds (U.S. Pat. No. 7,115,739), pyrazolylamine substituted quinazoline compounds (U.S. Pat. No. 7,098,330) and indazole compounds (U.S. Pat. No. 7,041,687) have all been described as protein kinase inhibitors. Several protein kinase inhibitors such as Glivec, Suten, and Sorafenib have been successfully approved by the FDA as anti-cancer therapies. Their clinical use demonstrated clear advantages over existing chemotherapeutical treatments, fueling continuing interest in the innovation of mechanism-based treatments using new compounds with chemical scaffold improvements with excellent oral bioavailability, significant anti-tumor activity, and lower toxicity at well-tolerated dose.
Histone deacetylase (HDAC) proteins play a critical role in regulating gene expression in vivo by altering the accessibility of genomic DNA to transcription factors. Specifically, HDAC proteins remove the acetyl group of acetyl-lysine residues on histones, which can result in nucleosomal remodelling (Grunstein, M., 1997, Nature, 389: 349-352). Due to their governing role in gene expression, HDAC proteins are associated with a variety of cellular events, including cell cycle regulation, cell proliferation, differentiation, reprogramming of gene expression, and cancer development (Ruijter, A-J-M., 2003, Biochem. J., 370: 737-749; Grignani, F., 1998, Nature, 391: 815-818; Lin, R-J., 1998, 391: 811-814; Marks, P-A., 2001, Nature Reviews Cancer, 1: 194). In fact, HDAC inhibitors have been demonstrated to reduce tumor growth in various human tissues and in animal studies, including lung, stomach, breast, and prostrate (Dokmanovic, M., 2005, J. Cell Biochenm., 96: 293-304).
Mammalian HDACs can be divided into three classes according to sequence homology. Class I consists of the yeast Rpd3-like proteins (HDAC 1, 2, 3, 8 and 11). Class II consists of the yeast HDA1-like proteins (HDAC 4, 5, 6, 7, 9 and 10). Class III consists of the yeast SIR2-like proteins (SIRT 1, 2, 3, 4, 5, 6 and 7).
The activity of HDAC1 has been linked to cell proliferation, a hallmark of cancer. Particularly, mammalian cells with knock down of HDAC1 expression using siRNA were antiproliferative (Glaser, K-B., 2003, Biochem. Biophys. Res. Comm., 310: 529-536). While the knock out mouse of HDAC1 was embryonic lethal, the resulting stem cells displayed altered cell growth (Lagger, G., 2002, EMBO J., 21: 2672-2681). Mouse cells overexpressing HDAC1 demonstrated a lengthening of G 2 and M phases and reduced growth rate (Bartl. S., 1997, Mol. Cell Biol., 17: 5033-5043). Therefore, the reported data implicate HDAC1 in cell cycle regulation and cell proliferation.
HDAC2 regulates expression of many fetal cardiac isoforms. HDAC2 deficiency or chemical inhibition of histone deacetylase prevented the re-expression of fetal genes and attenuated cardiac hypertrophy in hearts exposed to hypertrophic stimuli. Resistance to hypertrophy was associated with increased expression of the gene encoding inositol polyphosphate-5-phosphatase f (Inpp5f) resulting in constitutive activation of glycogen synthase kinase 3β (Gsk3β) via inactivation of thymoma viral proto-oncogene (Akt) and 3-phosphoinositide-dependent protein kinase-1 (Pdk1). In contrast, HDAC2 transgenic mice had augmented hypertrophy associated with inactivated Gsk3β. Chemical inhibition of activated Gsk3β allowed HDAC2-deficient adults to become sensitive to hypertrophic stimulation. These results suggest that HDAC2 is an important molecular target of HDAC inhibitors in the heart and that HDAC2 and Gsk3β are components of a regulatory pathway providing an attractive therapeutic target for the treatment of cardiac hypertrophy and heart failure (Trivedi, C-M., 2007, Nat. Med. 13: 324-331).
HDAC3 are maximally expressed in proliferating crypt cells in normal intestine. Silencing of HDAC3 expression in colon cancer cell lines resulted in growth inhibition, a decrease in cell survival, and increased apoptosis. Similar effects were observed for HDAC2 and, to a lesser extent, for HDAC1. HDAC3 gene silencing also selectively induced expression of alkaline phosphatase, a marker of colon cell maturation. Concurrent with its effect on cell growth, overexpression of HDAC3 inhibited basal and butyrate-induced p21 transcription in a Sp1/Sp3-dependent manner, whereas silencing of HDAC3 stimulated p21 promoter activity and expression. These findings identify HDAC3 as a gene deregulated in human colon cancer and as a novel regulator of colon cell maturation and p21 expression (Wilson, A-J., 2006, J. Biol. Chem., 281: 13548-13558).
HDAC6 is a subtype of the HDAC family that deacetylates alpha-tubulin and increases cell motility. Using quantitative real-time reverse transcription polymerase chain reaction and Western blots on nine oral squamous cell carcinoma (OSCC)-derived cell lines and normal oral keratinocytes (NOKs), HDAC6 mRNA and protein expression were commonly up-regulated in all cell lines compared with the NOKs. Immunofluorescence analysis detected HDAC6 protein in the cytoplasm of OSCC cell lines. Similar to OSCC cell lines, high frequencies of HDAC6 up-regulation were evident in both mRNA (74%) and protein (51%) levels of primary human OSCC tumors. Among the clinical variables analyzed, the clinical tumor stage was found to be associated with the HDAC6 expression states. The analysis indicated a significant difference in the HDAC6 expression level between the early stage (stage I and II) and advanced-stage (stage III and IV) tumors (P=0.014). These results suggest that HDAC6 expression may be correlated with tumor aggressiveness and offer clues to the planning of new treatments (Sakuma, T., 2006, Int. J. Oncol., 29: 117-124).
Epigenetic silencing of functional chromosomes by HDAC is one of the major mechanisms that occurrs in pathological processes in which functionally critical genes are repressed or reprogrammed by HDAC activities leading to the loss of phenotypes in terminal differentiation, maturation and growth control, and the loss of functionality of tissues. For example, tumor suppressor genes are often silenced during development of cancer and chemical inhibitors of HDAC can derepress the expression of these tumor suppressor genes, leading to growth arrest and differentiation (Glaros S et al., 2007, Oncogene June 4 Epub ahead of print; Mai, A, et al., 2007, Int J. Biochem Cell Bio., April 4, Epub ahead of print; Vincent A. et al., 2007, Oncogene, April 30, Epub ahead of print; our unpublished results). Repression of structural genes such as FXN in Friedreich's ataxia and SMN in spinal muscular atrophy can be reversed by HDAC inhibitors, leading to re-expression and resumption of FXN and SMN gene function in tissues (Herman D et al., 2006, Nature Chemical Biology, 2(10):551-8; Avila AM et al., 2007, J Clinic Investigation, 117(3)659-71; de Bore J, 2006, Tissue Eng. 12(10):2927-37); Induction of the entire MHC II family gene expression through reprogramming of HDAC “hot spot” in chromosome 6p21-22 by HDAC inhibitors further extends epigenetic modulation of immune recognition and immune response (Gialitakis M et al., 2007, Nucleic Acids Res., 34(1);765-72).
Several classes of HDAC inhibitors have been identified, including (1) short-chain fatty acids, e.g. butyrate and phenylbutyrate; (2) organic hydroxamic acids, e.g. suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA); (3) cyclic tetrapeptides containing a 2-amino-8-oxo 9,10-expoxydecanoyl (AOE) moiety, e.g. trapoxin and HC-toxin; (4) cyclic peptides without the AOE moiety, e.g. apicidin and FK228; and (5) benzamides, e.g. MS-275 (EP0847992A1, US2002/0103192A1, W002/26696A1, WO01/70675A2, WO01/18171A2). HDAC represents a very promising drug target especially in the context of epigenic biology; for example, in terms of preferential apoptosis-induction in malignant cells but not normal cells, differentiation of epithelia in cancer cells, anti-inflammatory and immunomodulation, and cell cycle arrest.
The use of HDAC inhibitors can be considered as “neo-chemotherapy” having a much improved toxicity profile over existing chemotherapy options. The success of SAHA from Merck is currently only limited to the treatment of cutaneous T cell lymphoma. No reports exist indicating that SAHA treatment is effective against major solid tumors or for any other indications. Therefore, there is still a need to discover new compounds with improved profiles, such as stronger HDAC inhibitory activity and anti-cancer activity, more selective inhibition on different HDAC subtypes, and lower toxicity; There is a continuing need to identify novel HDAC inhibitors that can be used to treat potential new indications such as neurological and neurodegenerative disorders, cardiovascular disease, metabolic disease, and inflammatory and immunological diseases.
SUMMARY OF THE INVENTION
The present invention is directed to certain 2-indolinone derivatives which are capable of selectively inhibiting protein kinases and histone deacetylases and are therefore useful in treating diseases associated with abnormal protein kinase activities and abnormal histone deacetylase activities. In particular, the compounds are highly effective against hematological malignancy and solid carcinomas.
DETAILED DESCRIPTION OF THE INVENTION
Various publications are cited throughout the present application. The contents of these publications and contents of documents cited in these publications are incorporated herein by reference.
Provided herein are new chemical compounds that combine anti-angiogenesis and anti-proliferation activities of RTK's together with differentiation-inducing, immune modulation, cell cycle arrest and apoptosis-induction activities of more selective HDACi, to reach a better efficacy against solid tumors while overcoming side effects such as hypertension, QT prolongation, thyroid gland regression, skin rash and discoloration, and pains associated with currently marketed RTK inhibitors.
Particularly, the present invention provides a compound having the structure represented by formula (I), or its stereoisomer, enantiomer, diastereomer, hydrate, or pharmaceutically acceptable salts thereof:
wherein
X is ═CH— or ═N—N═CH—; R 1 , R 2 , R 3 and R 4 are independently hydrogen, halo, alkyl alkoxy, nitro or trifluoromethyl; R 5 , R 6 , R 7 and R 8 are independently hydrogen, halo, alkyl alkoxy or trifluoromethyl; n is an integer ranging from 2 to 6.
In the above structural formula (I) and throughout the present specification, the following terms have the indicated meaning:
The term “halo” as used herein means fluorine, chlorine, bromine or iodine.
The term “alkyl” as used herein includes methyl, ethyl, n-propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert-butyl and the like.
The term “alkoxy” as used herein includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy and the like.
In one embodiment of a compound of formula (I), X is ═CH—; R 1 , R 2 , R 3 and R 4 are independently hydrogen, halo, alkyl alkoxy, nitro or trifluoromethyl; R 5 , R 6 , R 7 and R 8 are independently hydrogen, halo, alkyl alkoxy or trifluoromethyl; and n is an integer ranging from 2 to 4.
In another embodiment, X is ═CH—; R 1 , R 2 , R 3 and R 4 are independently hydrogen, halo, alkyl alkoxy, nitro or trifluoromethyl; R 5 , R 6 , R 7 and R 8 are independently H or F;and n is an integer ranging from 2 to 4.
In another embodiment, X is ═N—N═CH—; R 1 , R 2 , R 3 and R 4 are independently hydrogen, halo, alkyl alkoxy, nitro or trifluoromethyl; R 5 , R 6 , R 7 and R 8 are independently hydrogen, halo, alkyl alkoxy or trifluoromethyl; and n is an integer ranging from 2 to 4.
In another embodiment, X is ═N—N═CH—; R 1 , R 2 R 3 and R 4 are independently hydrogen, halo, alkyl alkoxy, nitro or trifluoromethyl; R 5 , R 6 , R 7 and R 8 are independently H or F; and n is an integer ranging from 2 to 4.
The compounds of this invention are prepared as described below:
(a) 6-Chloronicotinic acid is condensed with compound 1 to give compound 2;
(b) Compound 2 is condensed with compound 3 to give compound 4;
(c) Compound 4 is condensed with compound 5 to give compound 6.
Condensation reactions (a) and (c) are conducted by using a peptide condensing agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), dicyclohexylcarbodiimide (DCC), N,N′-carbonyldiimidazole (CDI), etc. The reaction may be conducted at 0 to 80° C. for 4 to 72 hours. Solvents which may be used are normal solvents such as benzene, toluene, tetrahydrofuran, dioxane, dichloromethane, chloroform, N,N-dimethylformamide, etc. If necessary, a base such as sodium hydroxide, triethylamine and pyridine may be added to the reaction system.
Condensation reaction (b) is conducted at 40 to 120° C. for 1 to 24 hours. Solvents which may be used are normal solvents such as benzene, toluene, tetrahydrofuran, dioxane, dichloromethane, chloroform, N,N-dimethylformamide, etc. If necessary, a base such as sodium hydroxide, triethylamine and pyridine may be added to the reaction system.
The compounds represented by formula (I) and the intermediate (2) and (4) may be purified or isolated by the conventional separation methods such as extraction, recrystallization, column chromatography and the like.
The compounds represented by formula (I) are capable of inhibiting protein kinases and histone deacetylases and are therefore useful in treating diseases associated with abnormal protein kinase activities and abnormal histone deacetylase activities. In particular, they are highly effective against hematological malignancy and solid carcinomas.
The compounds represented by formula (I) useful as a drug may be used in the form of a general pharmaceutical composition. The pharmaceutical composition may be in the forms normally employed, such as tablets, capsules, powders, syrups, solutions, suspensions, aerosols, and the like, may contain flavorants, sweeteners etc. in suitable solids or liquid carriers or diluents, or in suitable sterile media to form injectable solutions or suspensions. Such composition typically contains from 0.5 to 70%, preferably 1 to 20% by weight of active compound, the remainder of the composition being pharmaceutically acceptable carriers, diluents or solvents or salt solutions.
The compounds represented by formula (I) are clinically administered to mammals, including man and animals, via oral, nasal, transdermal, pulmonary, or parenteral routes. Administration by the oral route is preferred, being more convenient and avoiding the possible pain and irritation of injection. By either route, the dosage is in the range of about 0.0001 to 200 mg/kg body weight per day administered singly or as a divided dose. However, the optimal dosage for the individual subject being treated will be determined by the person responsible for treatment, generally smaller dose being administered initially and thereafter increments made to determine the most suitable dosage.
Representative compounds of the present invention are shown in Table 1 below. The compound numbers correspond to the “Example numbers” in the Examples section. That is, the synthesis of compound 3 as shown in the Table 1 is described in “Example 3” and the synthesis of compound 51 as shown in the Table 1 is described in “Example 51”. The compounds presented in the Table 1 are exemplary only and are not to be construed as limiting the scope of this invention in any manner.
TABLE 1
Example
Structure
Name
3
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((5-fluoro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)-nicotinamide
4
N-(2-Aminophenyl)-6-(2-(2-(((5- fluoro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)nicotinamide
6
(Z)-N-(2-Aminophenyl)-6-(3-(2- ((5-fluoro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- propylamino)-nicotinamide
7
N-(2-Aminophenyl)-6-(3-(2-(((5- fluoro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- propylamino)nicotinamide
9
(Z)-N-(2-Aminophenyl)-6-(4-(2- ((5-fluoro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)-butylamino)-nicotinamide
10
N-(2-Aminophenyl)-6-(4-(2-(((5- fluoro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- butylamino)nicotinamide
13
(Z)-N-(2-Amino-4-fluorophenyl)- 6-(2-(2-((5-fluoro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)nicotinamide
14
N-(2-Amino-4-fluorophenyl)-6-(2- (2-(((5-fluoro-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
16
(Z)-N-(2-Amino-4-fluorophenyl)- 6-(3-(2-((5-fluoro-2-oxoindolin- 3-ylidene)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- propyl-amino)nicotinamide
17
N-(2-Amino-4-fluorophenyl)-6-(3- (2-(((5-fluoro-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)propylamino)- nicotinamide
19
(Z)-N-(2-Amino-4-fluorophenyl)- 6-(4-(2-((5-fluoro-2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl-1H- pyrrole-4-carboxamido)butyl- amino)nicotinamide
20
N-(2-Amino-4-fluorophenyl)-6-(4- (2-(((5-fluoro-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)butylamino)- nicotinamide
23
(Z)-N-(2-Amino-4-chlorophenyl)- 6-(2-(2-((5-fluoro-2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl-1H- pyrrole-4-carboxamido)ethyl- amino)nicotinamide
24
N-(2-Amino-4-chlorophenyl)-6- (2-(2-(((5-fluoro-2-oxoindolin- 3-ylidene)hydrazono)methyl)- 3,5-dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
27
(Z)-N-(2-Amino-4-methylphenyl)- 6-(2-(2-((5-fluoro-2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl-1H- pyrrole-4-carboxamido)ethyl- amino)nicotinamide
28
N-(2-Amino-4-methylphenyl)-6- (2-(2-(((5-fluoro-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
31
(Z)-N-(2-Amino- 4-methoxyphenyl)-6-(2- (2-((5-fluoro-2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl-1H- pyrrole-4-carboxamido)ethyl- amino)nicotinamide
32
N-(2-Amino-4-methylphenyl)-6- (2-(2-(((5-fluoro-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
35
(Z)-N- (2-Amino-4-trifluoromethyl- phenyl)-6-(2-(2-((5-fluoro- 2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)-nicotinamide
36
N-(2-Amino-4-trifluoromethyl-phenyl)-6-(2-(2-(((5-fluoro-2- oxoindolin-3-ylidene)hydrazono)- methyl)-3,5-dimethyl-1H-pyrrole- 4-carboxamido)ethylamino)- nicotinamide
37
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((2-oxoindolin-3-ylidene)methyl)- 3,5-dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
38
N-(2-Aminophenyl)-6-(2-(2-(((2- oxoindolin-3-ylidene)hydrazono)- methyl)-3,5-dimethyl-1H-pyrrole- 4-carboxamido)ethylamino)- nicotinamide
39
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((5-chloro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)-nicotinamide
40
N-(2-Aminophenyl)-6-(2-(2-(((5- chloro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)ethyl- amino)nicotinamide
41
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((4-methyl-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethylamino)-nicotinamide
42
N-(2-Aminophenyl)-6-(2-(2-(((4- methyl-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)ethyl- amino)nicotinamide
43
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((5-nitro-2-oxoindolin-3-ylidene)- methyl)-3,5-dimethyl-1H-pyrrole- 4-carboxamido)ethylamino)- nicotinamide
44
N-(2-Aminophenyl)-6-(2-(2-(((5- nitro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)ethyl- amino)nicotinamide
45
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((6-methoxy-2-oxoindolin-3- ylidene)methyl)-3,5-dimethyl-1H- pyrrole-4-carboxamido)ethyl- amino)nicotinamide
46
N-(2-Aminophenyl)-6-(2-(2-(((6- methoxy-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)ethyl- amino)nicotinamide
47
(Z)-N-(2-Aminophenyl)-6-(2-(2- ((6-trifluoromethyl-2-oxoindolin- 3-ylidene)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- ethyl-amino)nicotinamide
48
N-(2-Aminophenyl)-6-(2-(2-(((6- trifluoromethyl-2-oxoindolin-3- ylidene)hydrazono)methyl)-3,5- dimethyl-1H-pyrrole-4- carboxamido)ethylamino)- nicotinamide
50
(Z)-N-(2-Aminophenyl)-6-(6-(2- ((5-fluoro-2-oxoindolin-3- ylidene)-methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)- hexylamino)-nicotinamide
51
N-(2-Aminophenyl)-6-(6-(2-(((5- fluoro-2-oxoindolin-3-ylidene)- hydrazono)methyl)-3,5-dimethyl- 1H-pyrrole-4-carboxamido)hexyl- amino)nicotinamid
Further, all parts and percentages in the examples, as well as in the remainder of the specification, are by weight unless otherwise specified. Any range of numbers recited in the specification or paragraphs hereinafter describing or claiming various aspects of the invention, such as that representing a particular set of properties, units of measure, conditions, physical states or percentages, is intended to literally incorporate expressly herein by reference or otherwise, any number falling within such range, including any subset of numbers or ranges subsumed within any range so recited. The term “about” when used as a modifier for, or in conjunction with, a variable, is intended to convey that the numbers and ranges disclosed herein are flexible and that practice of the present invention by those skilled in the art using temperatures, concentrations, amounts, contents, carbon numbers, and properties that are outside of the range or different from a single value, will achieve the desired result.
EXAMPLE 1
Preparation of N-(2-aminophenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and o-phenylenediamine (216 mg, 2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (138 mg, 56% yield) as a brown solid. LC-MS (m/z) 248 (M+1).
EXAMPLE 2
Preparation of N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Aminophenyl)-6-chloronicotinamide (248 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (150 mg, 55% yield) as a brown solid. LC-MS (m/z) 272 (M+1).
EXAMPLE 3
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (493 mg, 89%) as a yellow solid. 1 H NMR (DMSO-d 6 )δ2.41 (s, 3H, pyrrole-CH 3 ), 2.43 (s, 3H, pyrrole-CH 3 ), 3.43 (m, 2H, CH 2 ), 3.48 (m, 2H, CH 2 ), 4.86 (s, 2H, benzene-NH 2 ), 6.56 (m, 2H), 6.76 (d, J=8.0 Hz, 1H), 6.84 (m, 1H), 6.92 (m, 2H), 7.12 (d, J=8.0 Hz, 1H), 7.26 (s 1H), 7.71˜7.77 (m, 3H), 7.94 (d,J=8.0 Hz, 1H), 8.65 (s, 1H), 9.38 (s, 1H, benzene-NH), 10.90 (s, 1H, indolinone-NH), 13.69 (s, 1H, pyrrole-NH). LC-MS (m/z) 554 (M+1).
EXAMPLE 4
Preparation of N-(2-aminophenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (425 mg, 73%) as a red solid. 1 H NMR (DMSO-d 6 )δ2.35 (s, 3H, pyrrole-CH 3 ), 2.44 (s, 3H, pyrrole-CH 3 ), 3.42 (m, 2H, CH 2 ), 3.48 (m, 2H, CH 2 ), 4.85 (s, 2H, benzene-NH 2 ), 6.56 (m, 2H), 6.76 (d, J=8.0 Hz, 1H), 6.85 (m, 1H), 6.92 (m, 1H), 7.12 (d, J=8.0 Hz, 1H), 7.20˜7.25 (m, 2H), 7.71 (s, 1H), 7.93 (d, J=8.0 Hz, 1H), 8.33 (d, J=8.0 Hz, 1H), 8.64 (s, 2H), 9.38 (s, 1H, benzene-NH), 10.73 (s, 1H, indolinone-NH), 11.84 (s, 1H, pyrrole-NH). LC-MS (m/z) 582 (M+1).
EXAMPLE 5
Preparation of N-(2-aminophenyl)-6-(3-aminopropylamino)nicotinamide
N-(2-Aminophenyl)-6-chloronicotinamide (248 mg, 1 mmol) and 6 ml of 1,3-propanediamine were heated to 80° C. for 3 hours. The excess 1,3-propanediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (168 mg, 59% yield) as a brown solid. LC-MS (m/z) 286 (M+1).
EXAMPLE 6
Preparation of (Z)-N-(2-aminophenyl)-6-(3-(2-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)propylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(3-aminopropylamino)nicotinamide (299 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (465 mg, 82%) as a yellow solid. 1 H NMR (DMSO-d 6 )δ1.79 (m, 2H, CH2), 2.42 (s, 3H, pyrrole-CH 3 ), 2.44 (s, 3H, pyrrole-CH 3 ), 3.30 (m, 2H, CH2), 3.38 (m, 2H, CH2), 4.85 (s, 2H, benzene-NH 2 ), 6.51 (m, 1H), 6.58 (m, 1H), 6.75 (d, J=8.0 Hz, 1H), 6.83 (t, J=8.0 Hz, 1H), 6.92 (m, 2H), 7.12 (d, J=8.0 Hz, 1H), 7.19 (s, 1H), 7.71˜7.77 (m, 3H), 7.91 (d, J=8.0 Hz, 1H), 8.64 (s, 1H), 9.37(s, 1H, benzene-NH), 10.90 (s, 1H, indolinone-NH), 13.68 (s, 1H, pyrrole-NH). LC-MS (m/z) 568 (M+1).
EXAMPLE 7
Preparation of N-(2-aminophenyl)-6-(3-(2-(((5-fluoro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)propylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(3-aminopropylamino)nicotinamide (299 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (452 mg, 76%) as a red solid. 1 H NMR (DMSO-d 6 )δ1.78 (m, 2H, CH 2 ), 2.36 (s, 3H, pyrrole-CH 3 ), 2.45 (s, 3H, pyrrole-CH 3 ), 3.30 (m, 2H, CH 2 ), 3.38 (m, 2H, CH 2 ), 4.85 (s, 2H, benzene-NH 2 ), 6.51 (m, 1H), 6.57 (m, 1H), 6.75 (d, J=8.0 Hz, 1H), 6.85 (m, 1H), 6.93 (m, 1H), 7.12 (d, J=8.0 Hz, 1H), 7.20 (m, 2H), 7.71 (s, 1H), 7.92 (d, J=8.0 Hz, 1H), 8.34 (d, J=8.0 Hz, 1H), 8.64 (s, 2H), 9.37 (s, 1H, benzene-NH), 10.74 (s, 1H, indolinone-NH), 11.85 (s, 1H, pyrrole-NH). LC-MS (m/z) 596 (M+1).
EXAMPLE 8
Preparation of N-(2-aminophenyl)-6-(4-aminobutylamino)nicotinamide
N-(2-Aminophenyl)-6-chloronicotinamide (248 mg, 1 mmol) and 7 ml of 1,4-butanediamine were heated to 80° C. for 3 hours. The excess 1,4-butanediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (158 mg, 53% yield) as a brown solid. LC-MS (m/z) 300 (M+1).
EXAMPLE 9
Preparation of (Z)-N-(2-aminophenyl)-6-(4-(2-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)butylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(4-aminobutylamino)nicotinamide (314 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (447 mg, 77%) as a yellow solid. 1 H NMR (DMSO-d 6 )δ1.59 (m, 4H, CH 2 CH 2 ), 2.39 (s, 3H, pyrrole-CH 3 ), 2.41 (s, 3H, pyrrole-CH 3 ), 3.25 (m, 4H, 2×CH 2 ), 4.85 (s, 2H, benzene-NH 2 ), 6.49 (m, 1H), 6.57 (m, 1H), 6.75 (d, J=8.0 Hz, 1H), 6.83 (m, 1H), 6.91 (m, 2H), 7.12 (d, J=8.0 Hz, 1H), 7.18 (s, 1H), 7.67˜7.76 (m, 3H), 7.90 (d, J=8.0 Hz, 1H), 8.63 (s, 1H), 9.35 (s, 1H, benzene-NH), 10.88 (s, 1H, indolinone-NH), 13.66 (s, 1H, pyrrole-NH). LC-MS (m/z) 582 (M+1).
EXAMPLE 10
Preparation of N-(2-aminophenyl)-6-(4-(2-(((5-fluoro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)butylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(4-aminobutylamino)nicotinamide (314 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (444 mg, 73%) as a red solid. 1 H NMR (DMSO-d 6 )δ1.59 (m, 4H, CH 2 CH 2 ), 2.32 (s, 3H, pyrrole-CH 3 ), 2.43 (s, 3H, pyrrole-CH 3 ), 3.24 (m, 4H, 2×CH 2 ), 4.85 (s, 2H, benzene-NH 2 ), 6.49 (m, 1H), 6.57 (m, 1H), 6.76 (d, J=8.0 Hz, 1H), 6.85 (m, 1H), 6.93 (m, 1H), 7.12 (d, J=8.0 Hz, 1H), 7.20 (m, 2H), 7.67 (s, 1H), 7.89 (d, J=8.0 Hz, 1H), 8.33 (d, J=8.0 Hz, 1H), 8.63 (s, 2H), 9.35 (s, 1H, benzene-NH), 10.70 (s, 1H, indolinone-NH), 11.82 (s, 1H, pyrrole-NH). LC-MS (m/z) 610 (M+1).
EXAMPLE 11
Preparation of N-(2-amino-4-fluorophenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and 4-fluoro-o-phenylenediamine (151 mg, 1.2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (193 mg, 73% yield) as a brown solid. LC-MS (m/z) 266 (M+1).
EXAMPLE 12
Preparation of N-(2-amino-4-fluorophenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Amino-4-fluorophenyl)-6-chloronicotinamide (266 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (176 mg, 61% yield) as a brown solid. LC-MS (m/z) 290 (M+1).
EXAMPLE 13
Preparation of (Z)-N-(2-amino-4-fluorophenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(2-aminoethylamino)nicotinamide (303 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (457 mg, 80%) as a yellow solid. 1 H NMR (DMSO-d 6 )δ2.41 (s, 3H, pyrrole-CH 3 ), 2.43 (s, 3H, pyrrole-CH 3 ), 3.43 (m, 2H, CH 2 ), 3.48 (m, 2H, CH 2 ), 5.18 (s, 2H, benzene-NH 2 ), 6.33 (m, 1H), 6.53 (m, 2H), 6.84 (m, 1H), 6.91 (m, 1H), 7.07 (m, 1H), 7.25 (s, 1H), 7.71 (m, 3H), 7.92 (d, J=8.0 Hz, 1H), 8.64 (s, 1H), 9.31 (s, 1H, benzene-NH), 10.89 (s, 1H, indolinone-NH), 13.68 (s, 1H, pyrrole-NH). LC-MS (m/z) 572 (M+1).
EXAMPLE 14
Preparation of N-(2-amino-4-fluorophenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(2-aminoethylamino)nicotinamide (303 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (407 mg, 68%) as a red solid. 1 H NMR (DMSO-d 6 )δ2.35 (s, 3H, pyrrole-CH 3 ), 2.44 (s, 3H, pyrrole-CH 3 ), 3.42 (m, 2H, CH 2 ), 3.47 (m, 2H, CH 2 ), 5.18 (s, 2H, benzene-NH 2 ), 6.33 (m, 1H), 6.53 (m, 2H), 6.85 (m, 1H), 7.06 (m, 1H), 7.21˜7.25 (m, 2H), 7.71 (s, 1H), 7.93 (d, J=8.0 Hz, 1H), 8.33 (d, J=8.0 Hz, 1H), 8.64 (s, 2H) 9.31 (s, 1H, benzene-NH), 10.73 (s, 1H, indolinone-NH), 11.84 (s, 1H, pyrrole-NH). LC-MS (m/z) 600 (M+1).
EXAMPLE 15
Preparation of N-(2-amino-4-fluorophenyl)-6-(3-aminopropylamino)nicotinamide
N-(2-amino-4-fluorophenyl)-6-chloronicotinamide (266 mg, 1 mmol) and 6 ml of 1,3-propanediamine were heated to 80° C. for 3 hours. The excess 1,3-propanediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (158 mg, 52% yield) as a brown solid. LC-MS (m/z) 304 (M+1).
EXAMPLE 16
Preparation of (Z)-N-(2-amino-4-fluorophenyl)-6-(3-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)propylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(3-aminopropylamino)nicotinamide (318 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (456 mg, 78%) as a yellow solid. 1 H NMR (DMSO-d 6 )δ 1.78 (m, 2H, CH 2 ), 2.42 (s, 3H, pyrrole-CH 3 ), 2.44 (s, 3H, pyrrole-CH 3 ), 3.30 (m, 2H, CH 2 ), 3.38 (m, 2H, CH 2 ), 5.18 (s, 2H, benzene-NH 2 ), 6.33 (m, 1H), 6.51 (m, 2H), 6.84 (m, 1H), 6.90 (m, 1H), 7.06 (t, J=8.0 Hz, 1H), 7.20 (s, 1H), 7.71˜7.76 (m, 3H), 7.91 (d, J=8.0 Hz, 1H), 8.63 (s, 1H), 9.30 (s, 1H, benzene-NH), 10.90 (s, 1H, indolinone-NH), 13.68 (s, 1H, pyrrole-NH). LC-MS (m/z) 586 (M+1).
EXAMPLE 17
Preparation of N-(2-amino-4-fluorophenyl)-6-(3-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)propylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(3-aminopropylamino)nicotinamide (318 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (441 mg, 72%) as a red solid. 1 H NMR (DMSO-d 6 )δ1.77 (m, 2H, CH 2 ), 2.36 (s, 3H, pyrrole-CH 3 ), 2.45 (s, 3H, pyrrole-CH 3 ), 3.29 (m, 2H, CH 2 ), 3.38 (m, 2H, CH 2 ), 5.18 (s, 2H, benzene-NH 2 ), 6.32 (m, 1H), 6.51 (m, 2H), 6.85 (m, 1H), 7.06 (m, 1H), 7.20 (m, 2H), 7.71 (s, 1H), 7.90 (d, J=8.0 Hz, 1H), 8.33 (d, J=8.0 Hz, 1H), 8.64 (s, 2H), 9.29 (s, 1H, benzene-NH), 10.73 (s, 1H, indolinone-NH), 11.84 (s, 1H, pyrrole-NH). LC-MS (m/z) 614 (M+1).
EXAMPLE 18
Preparation of N-(2-amino-4-fluorophenyl)-6-(4-aminobutylamino)nicotinamide
N-(2-Amino-4-fluorophenyl)-6-chloronicotinamide (266 mg, 1 mmol) and 7 ml of 1,4-butanediamine were heated to 80° C. for 3 hours. The excess 1,4-butanediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (149 mg, 47% yield) as a brown solid. LC-MS (m/z) 318 (M+1).
EXAMPLE 19
Preparation of (Z)-N-(2-amino-4-fluorophenyl)-6-(4-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)butylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(4-aminobutylamino)nicotinamide (333 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (485 mg, 81%) as a yellow solid.
1 H NMR (DMSO-d 6 )δ 1.59 (m, 4H, CH 2 CH 2 ), 2.39 (s, 3H, pyrrole-CH 3 ), 2.41 (s, 3H, pyrrole-CH 3 ), 3.24 (m, 2H, CH 2 ), 3.34 (m, 2H, CH 2 ), 5.17 (s, 2H, benzene-NH 2 ), 6.33 (m, 1H), 6.50 (m, 2H), 6.83 (m, 1H), 6.91 (m, 1H), 7.06 (t, J=8.0 Hz, 1H), 7.18 (s, 1H), 7.67˜7.76 (m, 3H), 7.89 (d, J=8.0 Hz, 1H), 8.63 (s, 1H), 9.28 (s, 1H, benzene-NH), 10.89 (s, 1H, indolinone-NH), 13.67 (s, 1H, pyrrole-NH). LC-MS (m/z) 600 (M+1).
EXAMPLE 20
Preparation of N-(2-amino-4-fluorophenyl)-6-(4-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)butylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-fluorophenyl)-6-(4-aminobutylamino)nicotinamide (333 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (433 mg, 69%) as a red solid. 1 H NMR (DMSO-d 6 )δ1.58 (m, 4H, CH 2 CH 2 ), 2.32 (s, 3H, pyrrole-CH 3 ), 2.42 (s, 3H, pyrrole-CH 3 ), 3.24 (m, 2H, CH 2 ), 3.35 (m, 2H, CH 2 ), 5.18 (s, 2H, benzene-NH 2 ), 6.33 (m, 1H), 6.50 (m, 2H), 6.85 (m, 1H), 7.06 (m, 1H), 7.20 (m, 2H), 7.67 (s, 1H), 7.89 (d, J=8.0 Hz, 1H), 8.33 (d, J=8.0 Hz, 1H), 8.63 (s, 2H), 9.29 (s, 1H, benzene-NH), 10.74 (s, 1H, indolinone-NH), 11.83 (s, 1H, pyrrole-NH). LC-MS (m/z) 628 (M+1).
EXAMPLE 21
Preparation of N-(2-amino-4-chlorophenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and 4-chloro-o-phenylenediamine (171 mg, 1.2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (135 mg, 48% yield) as a brown solid. LC-MS (m/z) 282 (M+1).
EXAMPLE 22
Preparation of N-(2-amino-4-chlorophenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Amino-4-chlorophenyl)-6-chloronicotinamide (282 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (180 mg, 59% yield) as a brown solid. LC-MS (m/z) 306 (M+1).
EXAMPLE 23
Preparation of (Z)-N-(2-amino-4-chlorophenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-chlorophenyl)-6-(2-aminoethylamino)nicotinamide (321 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (446 mg, 76%) as a yellow solid. LC-MS (m/z) 588 (M+1).
EXAMPLE 24
Preparation of N-(2-amino-4-chlorophenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-chlorophenyl)-6-(2-aminoethylamino)nicotinamide (321 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (406 mg, 66%) as a red solid. LC-MS (m/z) 616 (M+1).
EXAMPLE 25
Preparation of N-(2-amin-4-methylophenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and 4-methyl-o-phenylenediamine (146 mg, 1.2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (164 mg, 63% yield) as a brown solid. LC-MS (m/z) 262 (M+1).
EXAMPLE 26
Preparation of N-(2-amino-4-methylphenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Amino-4-methyl-phenyl)-6-chloronicotinamide (261 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (145 mg, 51% yield) as a brown solid. LC-MS (m/z) 286 (M+1).
EXAMPLE 27
Preparation of (Z)-N-(2-amino-4-methylphenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-methylphenyl)-6-(2-aminoethylamino)nicotinamide (299 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (420 mg, 74%) as a yellow solid. LC-MS (m/z) 568 (M+1).
EXAMPLE 28
Preparation of N-(2-amino-4-methylphenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-methylphenyl)-6-(2-aminoethylamino)nicotinamide (299 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (363 mg, 61%) as a red solid. LC-MS (m/z) 596 (M+1).
EXAMPLE 29
Preparation of N-(2-amino-4-methoxyphenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and 4-methoxy-o-phenylenediamine (166 mg, 1.2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (144 mg, 52% yield) as a brown solid. LC-MS (m/z) 278 (M+1).
EXAMPLE 30
Preparation of N-(2-amino-4-methoxyphenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Amino-4-methoxyphenyl)-6-chloronicotinamide (277 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (144 mg, 48% yield) as a brown solid. LC-MS (m/z) 302 (M+1).
EXAMPLE 31
Preparation of (Z)-N-(2-amino-4-methoxyphenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-fFuoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-methoxyphenyl)-6-(2-aminoethylamino)nicotinamide (316 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (478 mg, 82%) as a yellow solid. LC-MS (m/z) 584 (M+1).
EXAMPLE 32
Preparation of N-(2-amino-4-methoxyphenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-methoxyphenyl)-6-(2-aminoethylamino)nicotinamide (316 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (397 mg, 65%) as a red solid. LC-MS (m/z) 612 (M+1).
EXAMPLE 33
Preparation of N-(2-amino-4-trifluoromethylphenyl)-6-chloronicotinamide
6-Chloronicotinic acid (157.5 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and 4-trifluoromethyl-o-phenylenediamine (211 mg, 1.2 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine and extracted with 200 ml of ethyl acetate. The ethyl acetate was removed under vacuum. To the residue was added 5 ml of absolute ethanol. The solids were collected by vacuum filtration, washed with absolute ethanol and dried under vacuum to give the title compound (418 mg, 42% yield) as a brown solid. LC-MS (m/z) 316 (M+1).
EXAMPLE 34
Preparation of N-(2-amino-4-trifluoromethylphenyl)-6-(2-aminoethylamino)nicotinamide
N-(2-Amino-4-trifluoromethylphenyl)-6-chloronicotinamide (316 mg, 1 mmol) and 5 ml of ethylenediamine were heated to 80° C. for 3 hours. The excess ethylenediamine was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (159 mg, 47% yield) as a brown solid. LC-MS (m/z) 340 (M+1).
EXAMPLE 35
Preparation of (Z)-N-(2-amino-4-trifluoromethylphenyl)-6-(2-(2-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Fluoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-trifluoromethylphenyl)-6-(2-aminoethylamino)nicotinamide (356 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (422 mg, 68%) as a yellow solid. LC-MS (m/z) 622 (M+1).
EXAMPLE 36
Preparation of N-(2-amino-4-trifluoromethylphenyl)-6-(2-(2-(((5-fluoro-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-amino-4-trifluorophenyl)-6-(2-aminoethylamino)nicotinamide (356 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (350 mg, 54%) as a red solid. LC-MS (m/z) 650 (M+1).
EXAMPLE 37
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(2-Oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (282 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (460 mg, 86%) as a yellow solid. LC-MS (m/z) 536 (M+1).
EXAMPLE 38
Preparation of N-(2-aminophenyl)-6-(2-(2-(((2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((2-Oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (310 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (394 mg, 70%) as a red solid. LC-MS (m/z) 564 (M+1).
EXAMPLE 39
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((5-chloro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Chloro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (316 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (444 mg, 77%) as a yellow solid. LC-MS (m/z) 570 (M+1).
EXAMPLE 40
Preparation of N-(2-aminophenyl)-6-(2-(2-(((5-chloro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Chloro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (344 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (376 mg, 63%) as a red solid. LC-MS (m/z) 598 (M+1).
EXAMPLE 41
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((4-methyl-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(4-Methyl-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (296 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (445 mg, 81%) as a yellow solid. LC-MS (m/z) 550 (M+1).
EXAMPLE 42
Preparation of N-(2-aminophenyl)-6-(2-(2-(((4-methyl-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((4-Methyl-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (324 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (438 mg, 76%) as a red solid. LC-MS (m/z) 578 (M+1).
EXAMPLE 43
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((5-nitro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(5-Nitro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (327 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (383 mg, 66%) as a yellow solid. LC-MS (m/z) 581 (M+1).
EXAMPLE 44
Preparation of N-(2-aminophenyl)-6-(2-(2-(((5-nitro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((5-Nitro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (355 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (450 mg, 74%) as a red solid. LC-MS (m/z) 609 (M+1).
EXAMPLE 45
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((6-methoxy-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(6-Methoxy-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (312 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (463 mg, 82%) as a yellow solid. LC-MS (m/z) 566 (M+1).
EXAMPLE 46
Preparation of N-(2-aminophenyl)-6-(2-(2-(((6-methoxy-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((6-Methoxy-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (340 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (397 mg, 67%) as a red solid. LC-MS (m/z) 594 (M+1).
EXAMPLE 47
Preparation of (Z)-N-(2-aminophenyl)-6-(2-(2-((6-trifluoromethyl-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
5-(6-Trifluoromethyl-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (350 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (356 mg, 59%) as a yellow solid. LC-MS (m/z) 604 (M+1).
EXAMPLE 48
Preparation of N-(2-aminophenyl)-6-(2-(2-(((6-trifluoromethyl-2-oxoindolin-3-ylidene)-hydrazono)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)ethylamino)nicotinamide
2-(((6-Trifluoromethyl-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (378 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(2-aminoethylamino)nicotinamide (284 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (341 mg, 54%) as a red solid. LC-MS (m/z) 632 (M+1).
EXAMPLE 49
Preparation of N-(2-aminophenyl)-6-(6-aminohexylamino)nicotinamide
N-(2-Aminophenyl)-6-chloronicotinamide (248 mg, 1 mmol) and 1,6-diaminohexane (5.80 g, 50 mmol) were heated to 80° C. for 3 hours. The excess 1,6-diaminohexane was removed under vacuum. To the residue was added 5 ml of 0.20 M NaOH. The mixture was extracted with 100 ml of ethyl acetate. The ethyl acetate was removed under vacuum to give the title compound (219 mg, 67% yield) as a brown solid. LC-MS (m/z) 328 (M+1).
EXAMPLE 50
Preparation of (Z)-N-(2-aminophenyl)-6-(6-(2-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)hexylamino)nicotinamide
5-(5-Fuoro-2-oxo-1,2-dihydro-indol-(3Z)-ylidenemethyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (300 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(6-aminohexylamino)nicotinamide (343 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (487 mg, 80%) as a yellow solid. LC-MS (m/z) 610 (M+1).
EXAMPLE 51
Preparation of N-(2-aminophenyl)-6-(6-(2-(((5-fluoro-2-oxoindolin-3-ylidene)hydrazono)-methyl)-3,5-dimethyl-1H-pyrrole-4-carboxamido)hexylamino)nicotinamide
2-(((5-Fluoro-2-oxoindolin-3-ylidene)hydrazono)methyl)-2,4-dimethyl-1H-pyrrole-4-carboxylic acid (328 mg, 1 mmol) and 8 ml of DMF were stirred at room temperature while 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (384 mg, 2 mmol), hydroxybenzotriazole (162 mg, 1.2 mmol), triethylamine (404 mg, 4 mmol) and N-(2-aminophenyl)-6-(6-aminohexylamino)nicotinamide (343 mg, 1.05 mmol) were added. The mixture was stirred for 20 hours at room temperature. The mixture was diluted with 400 mL of brine. The solids were collected by vacuum filtration, washed with water and dried under vacuum to give the title compound (427 mg, 67%) as a red solid. LC-MS (m/z) 638 (M+1).
EXAMPLE 52
In Vivo Inhibition of Receptor Tyrosine Kinase Activity Via Ligand-Dependent Cell Proliferation Assay by Compounds from Formula (I)
GI 50 nM GI 50 nM GI 50 nM (c-Kit (PDGF (VEGF Example ligand-dependent ligand-dependent ligand-dependent (compound) cell proliferation) cell proliferation) cell proliferation) 3 126 >1000 <1 4 >1000 >1000 1 6 46 >1000 9 7 >1000 >1000 387 9 32 105 12 10 >1000 >1000 568 13 151 >1000 7 14 >1000 >1000 201 16 105 >1000 39 17 >1000 >1000 460 19 42 >1000 81 20 >1000 >1000 330
Measurement of in vivo inhibition on receptor ligand-dependent cell proliferation:
PDGF dependent cell proliferation:
NIH-3T3 mouse fibroblasts cell line engineered to stably express human PDGFRβ was constructed and used to evaluate PDGF dependent cell proliferation. PDGFRβ NIH-3T3 cells were plated into 96-well plates at 5,000 per well and incubated with serum-free medium for 24 hours. Compounds and PDGF BB (50 ng/ml) were added and incubated for 72 hours in serum-free medium. The effects on proliferation were determined by addition of MTS reagent (Promega) according to the instruction, incubation for 2 hours at 37° C. in CO 2 incubator, and record the absorbance at 490 nm using an ELISA plate reader.
VEGF dependent cell proliferation:
HUVEC cells were plated into 96-well plates at 6,000 per well and incubated with serum-free medium for 2 hours. Compounds and VEGF 165 (50 ng/ml) were added and incubated for 72 hours in serum-free medium. The effects on proliferation were determined by addition of MTS reagent (Promega) according to the instruction, incubation for 2 hours at 37° C. in CO 2 incubator, and record the absorbance at 490 nm using an ELISA plate reader.
SCF dependent cell proliferation:
Mo7e cells (SCF dependent) were plated into 96-well plates at 15000 per well and incubated in 1640 medium with 10% FBS and SCF (50 ng/ml) for 24 hours. Compounds were added and incubated for 72 hours at 37° C. in CO 2 incubator. The effects on proliferation were determined by addition of MTS reagent (Promega) according to the instruction, incubation for 2 hours at 37° C. in CO 2 incubator, and record the absorbance at 490 nm using an ELISA plate reader.
EXAMPLE 53
In Vitro Inhibition of Enzyme Activities on 4 Different Receptor Tyrosine Kinases by Compounds from Formula (I)
Example IC 50 nM IC 50 nM IC 50 nM IC 50 nM (compound) (c-Kit) (PDGFβ) (VEGFR2) (Flt3) 3 157 780 11 76 4 >1000 >1000 12 870 6 76 >1000 45 132 7 >1000 >1000 634 451 9 23 276 35 25 10 >1000 >1000 >1000 >1000 13 534 468 43 63 14 >1000 >1000 324 432 16 242 >1000 72 623 17 >1000 >1000 >1000 >1000 19 65 >1000 157 21 20 >1000 >1000 >1000 >1000
Measurement of in vitro inhibition on enzyme activity of receptor tyrosine kinase:
PDGFRα Bioassay:
This assay is used to measure in vitro kinase activity of PDGFRα in an ELISA assay.
Materials and Reagent:
1. Streptavidin coated-96-well-white plate
2. Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100) (Cell Signaling)
3. HRP-labeled anti-mouse IgG (Upstate)
4. HTScan™ Tyrosine Kinase Buffer (4×)
5. DTT (1000×. 1.25 M)
6. ATP (10 mM)
7. FLT3 (Tyr589) Biotinylated Peptide Substrate (Cell Signaling)
8. PDGF Receptor α Kinase (Cell Signaling)
9. Wash Buffer: 1× PBS, 0.05% Tween-20 (PBS/T)
10. Bovine Serum Albumin (BSA)
11. Stop Buffer: 50 mM EDTA, pH 8
12. Enhanced chemiluminescence (ECL) (Amersham)
Procedure for performing the assay in 96-well plate:
1. Add 10 μl 10 mM ATP to 1.25 ml 6 μM substrate peptide. Dilute the mixture with dH 2 0 to 2.5 ml to make 2× ATP/substrate cocktail ([ATP]=400 μM, [substrate]=3 μm).
2. Immediately transfer enzyme from −80° C. to ice. Allow enzyme to thaw on ice.
3. Microcentrifuge briefly at 4° C. to bring liquid to the bottom of the vial. Return immediately to ice.
4. Add 10 μl of DTT (1.25 M) to 2.5 ml of 4× HTScan™ Tyrosine Kinase Buffer (240 mM HEPES pH 7.5, 20 mM MgCl 2 , 20 mM MnCl 2 , 12 μM Na 3 VO 4 ) to make DTT/Kinase buffer.
5. Transfer 1.25 ml of DTT/Kinase buffer to enzyme tube to make 4× reaction cocktail ([enzyme]=4 ng/μL in 4× reaction cocktail).
6. Incubate 12.5 μl of the 4× reaction cocktail with 12.5 μl/well of prediluted compound of interest (usually around 10 μM) for 5 minutes at room temperature.
7. Add 25 μl of 2× ATP/substrate cocktail to 25 μl/well preincubated reaction cocktail/compound. Final Assay Conditions for a 50 μl Reaction:
60 mM HEPES pH 7.5 5 mM MgCl 2 5 mM MnCl 2 3 μM Na 3 VO 4 1.25 mM DTT 200 μM ATP 1.5 μM peptide 50 ng PDGF Receptor Kinase
1. Incubate reaction plate at room temperature for 30 minutes.
2. Add 50 μl/well Stop Buffer (50 mM EDTA, pH 8) to stop the reaction.
3. Transfer 25 μl of each reaction and 75 μl dH 2 O/well to a 96-well streptavidin-coated plate and incubate at room temperature for 60 minutes.
11. Wash three times with 200 μl/well PBS/T
12. Dilute primary antibody, Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100), 1:1000 in PBS/T with 1% BSA. Add 100 μl/well of primary antibody.
13. Incubate at room temperature for 60 minutes.
14. Wash three times with 200 μl/well PBS/T
15. Dilute HRP labeled anti-mouse IgG 1:500 in PBS/T with 1% BSA. Add 100 μl/well diluted antibody.
16. Incubate at room temperature for 30 minutes.
17. Wash five times with 200 μl/well PBS/T.
18. Add 100 μl/well ECL Solution.
19. Detect luminescence with appropriate Plate Reader.
VEGFR1 Bioassay
This assay is used to measure in vitro kinase activity of VEGFR1 in an ELISA assay.
Materials and Reagent:
1. Streptavidin coated, 96-well, white plate
2. Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100) (Cell Signaling)
3. HRP-labeled anti-mouse IgG (Upstate)
4. HTScan™ Tyrosine Kinase Buffer (4×)
5. DTT (1000×. 1.25 M)
6. ATP (10 mM)
7. Gastrin Precursor (Tyr87) Biotinylated Peptide Substrate (Cell Signaling)
8. VEGF Receptor 1 Kinase (recombinant, human) (Cell Signaling)
9. Wash Buffer: 1× PBS, 0.05% Tween-20 (PBS/T)
10. Bovine Serum Albumin (BSA)
11. Stop Buffer: 50 mM EDTA pH 8
12. Enhanced chemiluminescence (ECL) (Amersham)
Procedure for performing the assay in 96-well plate:
1. Add 10 μl 10 mM ATP to 1.25 ml 6 μM substrate peptide. Dilute the mixture with dH 2 0 to 2.5 ml to make 2× ATP/substrate cocktail ([ATP]=400 μM, [substrate]=3 μm).
2. Immediately transfer enzyme from −80° C. to ice. Allow enzyme to thaw on ice.
3. Microcentrifuge briefly at 4° C. to bring liquid to the bottom of the vial. Return immediately to ice.
4. Add 10 μl of DTT (1.25 M) to 2.5 ml of 4× HTScan™ Tyrosine Kinase Buffer (240 mM HEPES pH 7.5, 20 mM MgCl 2 , 20 mM MnCl 2 , 12 μM Na 3 VO 4 ) to make DTT/Kinase buffer.
5. Transfer 1.25 ml of DTT/Kinase buffer to enzyme tube to make 4× reaction cocktail ([enzyme]=4 ng/μL in 4× reaction cocktail).
6. Incubate 12.5 μl of the 4× reaction cocktail with 12.5 μl/well of prediluted compound of interest (usually around 10 μM) for 5 minutes at room temperature.
7. Add 25 μl of 2× ATP/substrate cocktail to 25 μl/well preincubated reaction cocktail/compound. Final Assay Conditions for a 50 μl Reaction:
60 mM HEPES pH 7.5 5 mM MgCl 2 5 mM MnCl 2 3 μM Na 3 VO 4 1.25 mM DTT 200 μM ATP 1.5 μM peptide 100 ng VEGFR1 Kinase
8. Incubate reaction plate at room temperature for 30 minutes.
9. Add 50 μl/well Stop Buffer (50 mM EDTA, pH 8) to stop the reaction.
10. Transfer 25 μl of each reaction and 75 μl dH 2 O/well to a 96-well streptavidincoated plate and incubate at room temperature for 60 minutes.
11. Wash three times with 200 μl/well PBS/T
12. Dilute primary antibody, Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100), 1:1000 in PBS/T with 1% BSA. Add 100 μl/well of primary antibody.
13. Incubate at room temperature for 60 minutes.
14. Wash three times with 200 μl/well PBS/T
15. Dilute HRP labeled anti-mouse IgG 1:500 in PBS/T with 1% BSA. Add 100 μl/well diluted antibody.
16. Incubate at room temperature for 30 minutes.
17. Wash five times with 200 μl/well PBS/T.
18. Add 100 μl/well ECL Solution.
19. Detect luminescence with appropriate Plate Reader.
c-KIT Bioassay
This assay is used to measure in vitro kinase activity of c-KIT in an ELISA assay.
Materials and Reagent:
1. Streptavidin coated, 96-well, white plate
2. Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100) (Cell Signaling)
3. HRP-labeled anti-mouse IgG (Upstate)
4. HTScan™ Tyrosine Kinase Buffer (4×)
5. DTT (1000×. 1.25 M)
6. ATP (10 mM)
7. KDR (Tyr996) Biotinylated Peptide Substrate (Cell Signaling)
8. c-KIT Kinase (recombinant, human) (Cell Signaling)
9. Wash Buffer: 1× PBS, 0.05% Tween-20 (PBS/T)
10. Bovine Serum Albumin (BSA)
11. Stop Buffer: 50 mM EDTA pH 8
12. Enhanced chemiluminescence (ECL) (Amersham)
Procedure for performing the assay in 96-well plate:
1. Add 10 μl 10 mM ATP to 1.25 ml 6 μM substrate peptide. Dilute the mixture with dH 2 0 to 2.5 ml to make 2× ATP/substrate cocktail ([ATP]=40 μM, [substrate]=3 μm).
2. Immediately transfer enzyme from −80° C. to ice. Allow enzyme to thaw on ice.
3. Microcentrifuge briefly at 4° C. to bring liquid to the bottom of the vial. Return immediately to ice.
4. Add 10 μl of DTT (1.25 M) to 2.5 ml of 4× HTScan™ Tyrosine Kinase Buffer (240 mM HEPES pH 7.5, 20 mM MgCl 2 , 20 mM MnCl 2 , 12 μM Na 3 VO 4 ) to make DTT/Kinase buffer.
5. Transfer 1.25 ml of DTT/Kinase buffer to enzyme tube to make 4× reaction cocktail ([enzyme]=4 ng/μL in 4× reaction cocktail).
6. Incubate 12.5 μl of the 4× reaction cocktail with 12.5 μl/well of prediluted compound of interest (usually around 10 μM) for 5 minutes at room temperature.
7. Add 25 μl of 2× ATP/substrate cocktail to 25 μl/well preincubated reaction cocktail/compound. Final Assay Conditions for a 50 μl Reaction:
60 mM HEPES pH 7.5 5 mM MgCl 2 5 mM MnCl 2 3 μM Na 3 VO 4 1.25 mM DTT 20 μM ATP 1.5 μM peptide 100 ng c-KIT Kinase
8. Incubate reaction plate at room temperature for 30 minutes.
9. Add 50 μl/well Stop Buffer (50 mM EDTA, pH 8) to stop the reaction.
10. Transfer 25 μl of each reaction and 75 μl dH 2 O/well to a 96-well streptavidincoated plate and incubate at room temperature for 60 minutes.
11. Wash three times with 200 μl/well PBS/T
12. Dilute primary antibody, Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100), 1:1000 in PBS/T with 1% BSA. Add 100 μl/well of primary antibody.
13. Incubate at room temperature for 60 minutes.
14. Wash three times with 200 μl/well PBS/T
15. Dilute HRP labeled anti-mouse IgG 1:500 in PBS/T with 1% BSA. Add 100 μl/well diluted antibody.
16. Incubate at room temperature for 30 minutes.
17. Wash five times with 200 μl/well PBS/T.
18. Add 100 μl/well ECL Solution.
19. Detect luminescence with appropriate Plate Reader.
Flt3 Bioassay
This assay is used to measure in vitro kinase activity of Flt3 in an ELISA assay.
Materials and Reagent:
1. Streptavidin coated, 96-well, white plate
2. Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100) (Cell Signaling)
3. HRP-labeled anti-mouse IgG (Upstate)
4. HTScan™ Tyrosine Kinase Buffer (4×)
5. DTT (1000×. 1.25 M)
6. ATP (10 mM)
7. KDR (Tyr996) Biotinylated Peptide Substrate (Cell Signaling)
8. Flt3 Kinase (recombinant, human) (Cell Signaling)
9. Wash Buffer: 1× PBS, 0.05% Tween-20 (PBS/T)
10. Bovine Serum Albumin (BSA)
11. Stop Buffer: 50 mM EDTA pH 8
12. Enhanced chemiluminescence (ECL) (Amersham)
Procedure for performing the assay in 96-well plate:
1. Add 10 μl 10 mM ATP to 1.25 ml 6 μM substrate peptide. Dilute the mixture with dH 2 0 to 2.5 ml to make 2× ATP/substrate cocktail ([ATP]=400 μM, [substrate]=3 μm).
2. Immediately transfer enzyme from −80° C. to ice. Allow enzyme to thaw on ice.
3. Microcentrifuge briefly at 4° C. to bring liquid to the bottom of the vial. Return immediately to ice.
4. Add 10 μl of DTT (1.25 M) to 2.5 ml of 4× HTScan™ Tyrosine Kinase Buffer (240 mM HEPES pH 7.5, 20 mM MgCl 2 , 20 mM MnCl 2 , 12 μM Na 3 VO 4 ) to make DTT/Kinase buffer.
5. Transfer 1.25 ml of DTT/Kinase buffer to enzyme tube to make 4× reaction cocktail ([enzyme]=4 ng/μL in 4× reaction cocktail).
6. Incubate 12.5 μl of the 4× reaction cocktail with 12.5 μl/well of prediluted compound of interest (usually around 10 μM) for 5 minutes at room temperature.
7. Add 25 μl of 2× ATP/substrate cocktail to 25 μl/well preincubated reaction cocktail/compound. Final Assay Conditions for a 50 μl Reaction:
60 mM HEPES pH 7.5 5 mM MgCl 2 5 mM MnCl 2 3 μM Na 3 VO 4 1.25 mM DTT 200 μM ATP 1.5 μM peptide 10 units Flt3 Kinase
8. Incubate reaction plate at room temperature for 30 minutes.
9. Add 50 μl/well Stop Buffer (50 mM EDTA, pH 8) to stop the reaction.
10. Transfer 50 μl of each reaction and 50 μl dH 2 O/well to a 96-well streptavidincoated plate and incubate at room temperature for 60 minutes.
11. Wash three times with 200 μl/well PBS/T
12. Dilute primary antibody, Phospho-Tyrosine Monoclonal Antibody (P-Tyr-100), 1:1000 in PBS/T with 1% BSA. Add 100 μl/well of primary antibody.
13. Incubate at room temperature for 60 minutes.
14. Wash three times with 200 μl/well PBS/T
15. Dilute HRP labeled anti-mouse IgG 1:500 in PBS/T with 1% BSA. Add 100 μl/well diluted antibody.
16. Incubate at room temperature for 30 minutes.
17. Wash five times with 200 μl/well PBS/T.
18. Add 100 μl/well ECL Solution.
19. Detect luminescence with appropriate Plate Reader.
The assays to measure enzyme activity of all other receptor tyrosine kinases are essentially identical to that as exemplified in the case of VEGF, PDGF, c-Kit or Flt3 receptor tyrosine kinase assay except specific receptor tyrosine kinase reagent may be used in a given receptor tyrosine kinase context.
EXAMPLE 54
In Vitro Inhibition of Total HDAC Enzyme Activity and In Vivo Inhibition of HDAC Subtype Activity by Compounds from Formula (I)
Class I HDAC3 HDAC4/5 HDAC (GDF11 (MEF2 HDAC7 % inhibition (P21 reporter reporter reporter (Nur77 reporter of total assay) assay) assay) assay) HDAC % Max % Max % Max % Max enzyme Resp of Resp of Resp of Resp of Example activity at EC 50 CS055 EC 50 CS055 EC 50 CS055 EC 50 CS055 (compound) 30 μM μM at 3 μM μM at 3 μM μM at 3 μM μM at 3 μM CS055 46.2 3.5 100.0 3.2 100.0 15.1 100.0 6.8 100.0 SAHA 95.7 0.5 304.1 0.8 317.9 1.2 427.3 3.0 514.9 3 9.20 2.3 131.7 1.9 106.2 2.2 83.2 2.9 113.5 4 6.90 nd 3.3 nd 2.4 nd 4.9 nd 3.9 6 12.50 2.5 74.6 1.0 75.6 1.0 44.2 2.5 88.1 7 7.80 nd 6.2 nd 6.3 nd 2.6 nd 12.4 9 6.30 13.4 89.1 15.5 81.4 20.0 53.6 13.2 88.7 10 6.10 nd 7.3 nd 8.3 nd 12.8 nd 13.2 13 −2.60 nd 2.1 nd 1.8 nd 0.5 nd 6.4 14 1.00 nd 2.1 nd 2.0 nd 2.4 nd 4.5 16 6.70 nd 2.5 nd 1.8 nd −0.2 nd 6.5 17 4.00 nd 3.4 nd 3.8 nd 10.8 nd 3.5 19 7.30 nd 2.3 nd 2.0 nd 1.9 nd 6.0 20 3.50 nd 2.8 nd 4.1 nd 16.3 nd 1.0 nd*: not determined CS055: Chidamide is a HDACi currently in clinic development against cancers with good efficacy and toxicity profile from Chipscreen Biosciences
Measurement of in vitro inhibition of total HDAC enzyme activity:
The in vitro inhibition of total HDAC enzyme was determined by HDAC Fluorimetric Assay/Drug Discovery Kit (BIOMOL) according to manufacture's instruction.
1. Add Assay buffer, diluted trichostatin A or test inhibitor to appropriate wells of the microtiter plate. Following table lists examples of various assay types and the additions required for each test.
Fluor
HeLa Extract
Inhibitor
de Lys ™
Sample
Assay Buffer
(Dilution)
(5x)
Substrate (2x)
Blank
25
μl
0
0
25 μl
(No Enzyme)
Control
10
μl
15
μl
0
25 μl
Trichostatin A
0
15
μl
10
μl
25 μl
Test Sample
0
15
μl
10
μl
25 μl
2. Add diluted HeLa extract or other HDAC sample to all wells except those that are to be “No Enzyme Controls” (Blank).
3. Allow diluted Fluor de Lys™ Substrate and the samples in the microtiter plate to equilibrate to assay temperature (25° C.).
4. Initiate HDAC reactions by adding diluted substrate (25 μl) to each well and mixing thoroughly.
5. Allow HDAC reactions to proceed for desired length of time and then stop them by addition of Fluor de Lys™ Developer (50 μl). Incubate plate at room temperature (25° C.) for 10-15 min.
6. Read samples in a microtiter-plate reading fluorimeter capable of excitation at a wavelength in the range 350-380 nm and detection of emitted light in the range 440-460 nm.
Measurement of in vivo inhibition of HDAC subtype activity:
HDAC subtype selectivity inhibition assay of tested compounds was carried out by several reporter gene assays experiments. Briefly, HeLa cells were seeded in 96-well plates the day before transfection to give a confluence of 50-80%. Cells were transfected with one of reporter gene plasmid containing a promoter sequence or response element upstream of a luciferase gene construct using FuGene6 transfection reagent according to the manufacturer's instruction (Roche). The promoters or response elements including p21-promoter, gdf11-promoter, MEF-binding element (MEF2), Nur77-promoter were fused upstream to the luciferase gene reporter construct. For normalizing the transfection efficiency, a GFP expression plasmid was cotransfected. Cells were allowed to express protein for 24 hours followed by addition of individual compounds or the vehicle (DMSO). 24 hours later the cells were harvested, and the luciferase assay and GFP assay were performed using corresponding assay kits according to the manufacturer's instructions (Promega).
EXAMPLE 55
In Vivo Anti-Proliferation by Compounds from Formula (I)
GI 50 GI 50 μM GI 50 GI 50 GI 50 GI 50 μM in GI 50 GI 50 GI 50 GI 50 GI 50 GI 50 in μM μM in μM Example μM in Hut- μM in μM in μM in μM in μM in μM in Bel- in MDA-M in (compound) HL60 78 Raji Jurkat U937 Ramos A549 HeLa 7402 MCF7 B-231 HCT-8 3 4.15 1.77 3.45 >60 >60 >60 >60 >60 >60 >60 >60 >60 4 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 6 >60 >60 3.45 >60 >60 >60 >60 >60 >60 >60 >60 >60 7 7.91 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 9 1.27 1.67 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 10 6.28 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 13 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 14 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 16 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 17 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 19 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 20 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 >60 CS055 1.00 1.69 9.29 3.79 2.50 >60 13.75 21.29 28.06 >60 36.15 >60 Sorafinib 1.28 12.54 4.15 16.91 4.06 1.51 13.75 30.77 9.73 9.51 4.25 5.35 Sutent 1.73 4.06 5.47 7.05 8.28 11.97 14.73 9.29 13.13 7.55 4.66 12.25 Note: Chidamide is a HDAC inhibitor currently in clinic development against cancers with preference against class I HDAC enzyme; Suten and Sorafinib are two marketed RTK and Ser/Thr kinase inhibitors with broad activity against many different receptor tyrosine or ser/thr kinases
Measurement of in vivo cell proliferation:
Tumor cells were trypsinized and plated into 96-well plates at 3,000 per well and incubated in complete medium with 10% FBS for 24 hours. Compounds were added over a final concentration range of 100 μmol/L to 100 nmol/L in 0.1% DMSO and incubated for 72 hours in complete medium. The effects on proliferation were determined by addition of MTS reagent (Promega) according to the instruction, incubation for 2 hours at 37° C. in CO 2 incubator, and record the absorbance at 490 nm using an ELISA plate reader.
Human Cell lines are listed below:
HL-60:
Acute promyelocytic leukemia
Hut-78:
Cutaneous T cell lymphoma
Raji:
Burkitt's lymphoma
Jurkat:
T cell leukemia
U937:
Histiocytic lymphoma
Ramos:
Burkitt's lymphoma
A549:
Non small cell lung carcinoma
HeLa:
Cervix adenocarcinoma
Bel-7402:
Hepatocellular carcinoma
MCF-7:
Mammary gland adenocarcinoma
MDA-MB-231:
Mammary gland adenocarcinoma
HCT-8:
Ileocecal colorectal adenocarcinoma | The present invention relates to 2-indolinone derivatives which are capable of inhibiting protein kinases and histone deacetylases. The compounds of this invention are therefore useful in treating diseases associated with abnormal protein kinase activities or abnormal histone deacetylase activities. Pharmaceutical compositions comprising these compounds, methods of treating diseases utilizing pharmaceutical compositions comprising these compounds, and methods of preparing these compounds are also disclosed. | 2 |
BACKGROUND OF THE INVENTION
There is a significant industrial interest in the production of the compound eritadenine, particularly for but not limited to, its potential use as a blood cholesterol reducing therapeutic agent for humans. The fungus Lentinus edodes , more commonly known as the shiitake mushroom, is known to produce eritadenine when the fungus forms the fruit body of the mushroom. In prior art it was discussed that eritadenine could only be formed in significant amounts by causing the formation of the fruit body. This is a problem since the cost of raising shiitake solely for extraction of the eritadenine is prohibitive. In order to produce the eritadenine as a therapeutic agent there is a need to be able to produce it in fermentive culture.
SUMMARY OF THE INVENTION
The present invention provides a solution to the problem of producing eritadenine in liquid phase fermentation of Lentinus edodes without formation of the fruit body. In particular, the present invention provides a solution to the problem above by exposing the fungus to shear during its cultivation, it not only produces eritadenine, but also secretes it extracellularly into the fermentation medium. Thus, the new method disclosed in the present invention makes liquid phase fermentation a viable method for industrial eritiadenine production.
The invention discloses a method for producing eritadenine in liquid phase fermentation of Lentinus edodes herein the Lentinus edodes is exposed to shear during its cultivation.
Further example is the method above wherein Lentinus edodes also secretes eritadenine extracellularly into the fermentation medium.
The shear is in the order of a stirring rate of about at least 25 rpm.
The pH is in the range of about 3.0-6.0, preferably 4.0-5.0.
It is important to maintain a filamentous structure and not allow the organism to form a pellet structure. The shear accomplishes this.
Analogous, mutated variants thereof and derivate of Lentinus edodes could be used and is within the scope of the present invention.
The shiitake mushroom ( Lentinus edodes ) is traditionally used in East Asia, but ever since the last decades it is cultivated and consumed worldwide. In addition to being a popular edible fungus, it is well established as a medicinal mushroom since it contains several substances promoting health. Among other things, the ability to reduce blood cholesterol in both animals and humans has been ascribed to this mushroom (1-4). The agent responsible for the plasma cholesterol reducing effect is an adenine derivative designated as eritadenine (Eritadenine was designated as lentinacin or lentysine by the research groups initially isolating it, before given its trivial name.), 2(R),3(R)-dihydroxy-4-(9-adenyl)-butyric acid (5, 6), and its hypocholesterolemic effects has been shown in several studies on rats (5, 7-15). The hypocholesterolemic action of eritadenine has been investigated in several studies on rats, but the mechanism by which eritadenine bring about its hypocholesterolemic effect is not fully elucidated. Eritadenine is suggested to accelerate the removal of blood cholesterol either by stimulated tissue uptake or by inhibited tissue release; there are no indications of this compound inhibiting the biosynthesis of cholesterol (15) and the hepatic cholesterol levels in rats are not lowered by eritadenine (8, 15). Further, it has been shown that plasma cholesterol levels are significantly decreased in rats fed 0.005% of eritadenine in their diets (5, 9, 13, 14) and that the hypocholesterolemic action is caused by a decrease of the phosphatidylcholine (PC)/phophatidylethanolamine (PE) ratio (9-13). Eritadenine is a very potent inhibitor of the enzyme S-adenosyl-L-homocysteine hydrolase in rat liver cells (16) hereby causing an increase in the S-adenosylhomocysteine concentration (17). The increase in S-adenosylhomocysteine concentration in turn inhibits the PE N-methylation, thus increasing the PE content in liver microsomes (12). Further studies on rats suggest that eritadenine may increase the uptake of plasma lipoprotein cholesterol by the liver and thus reduce the plasma cholesterol (13). There is a possibility that the change in composition of the membrane phospholipids may activate lipoprotein receptors in liver cell membranes, thus regulating the uptake of plasma lipoprotein lipids (9).
The amounts of eritadenine in the fruit bodies of shiitake, as determined by column chromatography fractionation or GC, were found to be in the range 0.5-0.7 and 0.3-0.4 mg/g dried caps and stems, respectively (18, 19). Later studies pertaining to HPLC analysis of extracts from different fruit bodies of shiitake have shown eritadenine amounts in the range 3.17-6.33 mg/g mushrooms (20). The mycelia of shiitake have also been found to contain eritadenine; the amount determined by GC analysis was 0.737 mg/g dried biomass (21). Although fruit bodies seem to contain significantly higher amounts of eritadenine, growing fruit bodies of shiitake is a fairly demanding and time consuming process. Hence, in search for a source of eritadenine, mycelia could be an alternative to the fruit bodies.
The use of fungi for their biochemical activities is not a new phenomenon and in the later decades submerged cultivations of fungi for production of commercially important products have increased. Filamentous fungi, like shiitake, are morphologically complex organisms and exhibit different hyphal morphologies in submerged culture and thus differences in metabolism and production of secondary metabolites, such as eritadenine. The morphology of filamentous fungi in liquid culture is a result of the organism used and the chemical and physical culturing conditions, and it can range from freely dispersed filaments to densely interwoven aggregates. There is no generally preferred mycelial structure; which morphology is desirable for maximal yield depends on the product in question. The reason why shiitake mushrooms synthesize eritadenine is yet not clarified; i.e. the purpose this compound serves for the mushroom as well as the circumstances for its production is not elucidated. Therefore it is of great interest to investigate shiitake mycelia for eritadenine production; submerged cultivation of mycelia offers a convenient way to change the conditions in order to improve eritadenine yield and productivity. Hence, stirring rate and pH, two major factors influencing the morphology and probably eritadenine production, were investigated in the present invention.
Further, no data investing the broth from liquid cultures of shiitake mycelia for eritadenine content has been found in the literature. Eritadenine produced by submerged cultivation of shiitake mycelia could be an efficient process and if the compound of interest is excreted to the medium its availability increases and thus the convenience of harvesting. Therefore, the goal of the present invention was to evaluate if submerged cultivation of shiitake mycelia could be a conceivable way of producing eritadenine. The mycelia were cultivated under different conditions and both the biomass and culture broth were investigated for its eritadenine content.
DETAILED DESCRIPTION OF THE INVENTION
Results and Discussion
In search for a potential source of the blood cholesterol lowering compound eritadenine, as an alternative to fruit bodies of shiitake, its mycelia were investigated. Filamentous fungi, like shiitake, exhibit different hyphal morphologies in submerged cultures, depending on the cultivation conditions. The metabolism and production of secondary metabolites, such as eritadenine, might in turn be affected by the morphology of the mycelia. For this reason, the mycelia were cultivated in different conditions in order to investigate the effect of pH and stirring rate on production of eritadenine. The reason and circumstances for shiitake to produce eritadenine is not known, and there exists no data in the literature on its content in the broth from submerged cultivation. Therefore, not only the mycelia but also the resulting broths were analyzed for eritadenine content. In this study eritadenine was found in both the mycelia and the surrounding media, see table 1. In the shake flask cultures the lowest eritadenine content was detected. In this case there is no impeller and hence the mycelia form macroscopic aggregates, pellets. The mycelial morphology in the bioreactor cultivations were freely dispersed filaments, and the eritadenine content were higher than in the shake flasks. In all cases the initial pH was 5.8, but during growth the pH dropped to 3.0 in the shake flasks. This low final pH indicates acid production. Further, in the cases where pH was uncontrolled, the final pH in the bio-reactors was 4.2 and 5.0 at 250 and 50 rpm, respectively. Clearly, the mycelia change their metabolism and acid production, depending on the physical culture conditions. According to previous studies (25) optimum pH for growth of shiitake mycelia is 3.0-3.5, while for production of antibacterial substances the optimum pH was 4.5. The low final pH in shake flasks combined with the relatively low amount of eritadenine indicate that for eritadenine production, a pH higher than 3.0 is preferable. Further, the results from the bioreactor cultivations indicate that lower pH than 5.7 favour eritadenine production, at the same stirring rate. When comparing the biomass produced, the higher agitation speed (250 rpm) runs resulted in about double the mycelial biomass than runs at lower (50 rpm) agitation speed, whereas eritadenine production was higher in the latter case. Taken together, the results from this study show that eritadenine is produced by shiitake mycelia and the major part of it is excreted to the surrounding medium. The results also indicate that the optimal conditions for mycelial biomass production and eritadenine production not necessarily coincide.
The following examples provided in table 1 are intended only to further illustrate the invention and are not intended to limit the scope of the invention. Thus, stirring rates or agitation speeds are only intended as examples. The stirring rates could vary from at least 25 to as high as is possible in order to producing eritadenine in liquid phase fermentation. The stirring rates depends on the size of the impeller. Thus, the skilled person in the field could optimize the method depending on the available equipment. Examples of stirring rates could then be; 25, 50, 100, 250, 500, 1000, 1500, 2000, 3000, 4000, 5000, 6000, and 7000. The preferred pH interval is in the order of 3.0 to 6.0. Other examples of intervals are 3.0-5.7, 3.5-5.7, 3.5-5,0, 4.0-5.0, etc.
One example of exposing Lentinus edodes to shear during its cultivation is stirring but other agitation techniques could be used. Any type of equipment such as a bioreactor could be used.
TABLE 1
Eritadenine content measured in the shiitake mycelia and culture
broth from various submerged cultivations by HPLC analysis.
Eritadenine amounts
In broth
Total amount
In biomass
(mg/g
(mg/g
Cultivation conditions
(mg/g mycelia)
mycelia)
mycelia)
Shake flask, 150 rpm, 23° C.,
0.64
5.91
6.55
no pH control
Bioreactor, 250 rpm, 25° C.,
1.40
24.60
26.00
pH 5.7
Bioreactor, 250 rpm, 25° C.,
0.2
32.41
32.61
no pH control
Bioreactor, 50 rpm, 25° C.,
0.36
33.46
33.82
pH 5.7
Bioreactor, 50 rpm, 25° C.,
0.10
39.43
39.53
no pH control
EXAMPLES
Material and Methods
Fungal material. The shiitake strain used was Lentinus edodes -2 (Le-2). Mycelia of this strain were kindly supplied by Dr. Gary L. Mills, Diversified Natural Products, Inc., Scottville, Mich., USA. The mycelia were cultivated on malt yeast agar (MYA) plates composed of (w/v) 2% malt extract, 0.2% yeast extract and 2% microbial agar, for 10 days at 23° C.
Shake flask cultures. Mycelia from MYA plates were homogenised in a 0.05 mM phosphate buffer, pH 5.8, and transferred to 200 mL of malt-yeast medium composed of (w/v) 2% malt extract and 0.2% yeast extract, with 2% glucose added. The submerged cultivation took place in 500 mL shake flasks at 150 rpm for 20 days at 23° C. Following cultivation, the mycelia were harvested by filtering the culture through Whatman OOH filter paper and washed with distilled water. The biomass was then dried over night and the dry weight determined. The filtrated broth was collected for further analysis.
Bioreactor cultivation. Mycelia from MYA plates were homogenised in a 0.05 mM phosphate buffer, pH 5.8, and transferred to 700 mL malt-yeast medium composed of (w/v) 2% malt extract, 0.2% yeast extract, with 2% glucose added. The submerged cultivation took place in 1 L bioreactors (Biobundle 1 L, Applikon Biotechnology, the Netherlands) with a stirring rate of either 50 or 250 rpm, a temperature of 25° C., a dissolved oxygen flowrate of 1/vol/vol, and a pH either controlled at 5.7 or uncontrolled. After 20 days of cultivation the mycelia were harvested by filtering the culture through Whatman OOH filter paper and washed with distilled water. The biomass was then dried over night and the dry weight determined. The filtrated broth was collected for further analysis.
Preparation of eritadenine standard. Eritadenine was synthesized according to the following procedure. In the first step, methyl 2,3-O-Isopropylidene-β-D-ribofuranoside was synthesized (22). This product was further processed to give the compound methyl 2,3-O-isopropylidene-5-O-p-toluenesulfonyl-β-D-ribofuranoside (23). The third step was a reaction of sodium salt of adenine with methyl 2,3-O-Isopropylidene-5-O-p-toluenesulfonyl-β-D-ribofuranoside. This reaction gave the product methyl 5-(6-Aminopurin-9H-9-yl)-2,3-O-isopropylidene-5-deoxy-β-D-ribofuranoside. Hydrolysis of this product resulted in 5-(6-Aminopurin-9H-9-yl)-5-deoxy-D-ribofuranose. The final step was an air oxidation of the previous compound to get the product; 2(R),3(R)-dihydroxy-4-(9-adenyl)-butyric acid, i.e. d-eritadenine (24). All chemicals were of analytical grade. In order to verify the correct product and its purity, NMR analysis was conducted for each step of the synthesis and compared with the literature. An LC/MS run further confirmed the final product. A stock solution (1.98 mg/mL) of the standard was prepared by dissolving synthesized eritadenine in distilled water.
Extraction of eritadenine from mycelia. The mycelial biomass was extracted with 80% (v/v) methanol for about 3 hours under reflux, with a solid-liquid ratio of 1:20. The fungal extract was then filtered through Whatman No. 5 filter paper and washed with distilled water. The resulting filtrate was concentrated in vacuo at 50-60° C. and analyzed.
Ion exchange purification of culture medium. The broth was concentrated in vacuo and the pH adjusted to 5.8 and applied to a column of Amberlite IR-120 (H + ) ion exchange resin. The substance was eluted with 2% ammonia, showing high absorbance at 260 nm. The volume collected was evaporated to dryness in vacuo at 50-60° C., diluted in 50 mL distilled water and applied to an Amberlite IRA-67 (OH − ) ion exchange resin. The substance was eluted with 0.1 M acetic acid and fractions showing high absorbance at 260 nm were collected. After evaporation to dryness in vacuo at 50-60° C. the mushroom sample was dissolved in distilled water and analyzed.
HPLC analysis. The eritadenine concentrations in shiitake mycelia and culture broth were analyzed by HPLC (Series 200 Quaternary LC pump and UV-VIS detector, TotalChrom software, PerkinElmer) and separated over a C18 column (RESTEK ultra aqueous, 5 μm, 4.6 mm×150 mm). Prior to analysis the samples were diluted twice with the initial mobile phase and filtered through a 0.2 μm syringe filter. The HPLC analysis was conducted at 23° C., with a flow rate of 1 mL/min and UV detection at 260 nm. The initial mobile phase was 0.05% TFA in aqueous solution: 0.05% TFA in MeCN, in the proportions 98:2 followed by a linear change to 40:60 over 10 min, and then returned to the initial condition for 15 min. All data were collected and processed using PerkinElmer's TotalChrom analytical software. Peak areas from the chromatograms were evaluated on the basis of a reference curve prepared from standard samples of eritadenine diluted in the initial mobile phase to concentrations in the range 0.0124-0.198 mg/mL.
REFERENCES
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4. Suzuki, S.; Ohshima, S., Influence of shiitake ( Lentinus edodes ) on human serum cholesterol. Mushroom Sci. 1974, 9, 463-467.
5. Chibata, I.; Okumura, K.; Takeyama, S.; Kotera, K., Lentinacin: a new hypocholesterolemic substance in Lentinus edodes . Experientia 1969, 25, 1237-1238.
6. Kamiya, T.; Saito, Y.; Hashimoto, M.; Seki, H., Structure and synthesis of lentysine, a new hypocholesterolemic substance. Tetrahedron Letters 1969, 10, 4729-4732.
7. Tokita, F.; Shibukawa, N.; Yasumoto, T.; Kaneda, T., Isolation and chemical structure of the plasma-cholesterol reducing substances from shiitake mushroom. Mushroom Sci. 1972, 8, 783-788.
8. Rokujo, T.; Kikuchi, H.; Tensho, A.; Tsukitani, Y.; Takenawa, T.; Yoshida, K.; Kamiya, T., Lentysine: a new hypolipidemic agent from a mushroom. Life Sci. 1970, 9, 379-385.
9. Shimada, Y.; Morita, T.; Sugiyama, K., Eritadenine-induced alterations of plasma lipoprotein lipid concentrations and phosphatidylcholine molecular species profile in rats fed cholesterol-free and cholesterol-enriched diets. Biosci. Biotechnol. Biochem. 2003, 67, 996-1006.
10. Shimada, Y.; Morita, T.; Sugiyama, K., Dietary eritadenine and ethanolamine depress fatty acid desaturase activities by increasing liver microsomal phosphatidylethanolamine in rats. J. Nutr. 2003, 133, 758-765.
11. Shimada, Y.; Yamakawa, A.; Morita, T.; Sugiyama, K., Effects of dietary eritadenine on the liver microsomal delta 6-desaturase activity and its mRNA in rats. Biosci. Biotechnol. Biochem. 2003, 67, 1258-1266.
12. Sugiyama, K.; Akachi, T.; Yamakawa, A., Eritadenine-induced alteration of hepatic phospholipid-metabolism in relation to its hypocholesterolemic action in rats. J. Nutr. Biochem. 1995, 6, 80-87.
13. Sugiyama, K.; Yamakawa, A.; Kawagishi, H.; Saeki, S., Dietary eritadenine modifies plasma phosphatidylcholine molecular species profile in rats fed different types of fat. J. Nutr. 1997, 127, 593-599.
14. Takashima, K.; Izumi, K.; Iwai, H.; Takeyama, S., The hypocholesterolemic action of eritadenine in the rat. Atherosclerosis. 1973, 17, 491-502.
15. Takashima, K.; Sato, C.; Sasaki, Y.; Morita, T.; Takeyama, S., Effect of eritadenine on cholesterol metabolism in the rat. Biochem. Pharmacol. 1974, 23, 433-438.
16. Votruba, I.; Holý, A., Eritadenine a novel type of potent inhibitors of S-adenosyl-L-homocysteine hydrolase. Collect. Czech. Chem. Commun. 1982, 47, 167-172.
17. Schanche, J.; Schanche, T.; Ueland, P.; Holy, A.; Votruba, I., The effect of aliphatic adenine analogues on S-adenosylhomocysteine and S-adenosylhomocysteine hydrolase in intact rat hepatocytes. Mol. Pharmacol. 1984, 26, 553-558.
18. Saito, M.; Yasumoto, T.; Kaneda, T., Quantitative analyses of eritadenine in shiitake mushroom and other edible fungi. J. Jap. Soc. Food Nutr. 1975, 28, 503-513.
19. Vitanyi, G.; Lelik, L.; Bihatsi-Karsai, E.; Lefler, J.; Nagy-Gasztonyi, M.; Vereczkey, G., Detection of eritadenine in extracts from shiitake mushroom by gas chromatography mass spectrometry. Rapid Commun. Mass Spectrom. 1998, 12, 120-122. 20. Enman, J.; Rova, U.; Berglund, K. A., Quantification of the bioactive compound eritadenine in selected strains of shiitake mushroom ( Lentinus edodes ). J. Agric. Food. Chem. 2007, 55, (4), 1177-1180. 21. Lelik, L.; Vitanyi, G.; Lefler, J.; Hegoczky, J.; Nagy-Gasztonyi, M.; Vereczkey, G., Production of the mycelium of shiitake ( Lentinus edodes ) mushroom and investigation of its bioactive compounds. Acta Alimentaria 1997, 26, 271-277. 22. Leonard, N. J.; Carraway, K. L., 5-amino-5-deoxyribose derivatives. Synthesis and use in the preparation of reversed nucleosides. J. Heterocycl. Chem. 1966, 3, 485-489. 23. Levene, P. A.; Stiller, E. T., Acetone Derivatives of d-Ribose. J. Biol. Chem. 1934, 106, 421-429. 24. Kawazu, M.; Kanno, T.; Yamamura, S.; Mizoguchi, T.; Saito, S., Studies on the oxidation of “reversed nucleosides” in oxygen. I. Synthesis of eritadenine and its derivatives. J. Org. Chem. 1973, 38, 2887-90. 25. Hassegawa, R. H.; Kasuya, M. C. M.; Vanetti, M. C. D., Growth and antibacterial activity of Lentinula edodes in liquid media supplemented with agricultural wastes. Electr. J. Biotech. 2005, 8, 212-217. | Method to produce eritadenine by liquid phase fermentation of Lentinus edodes without formation of the fruit body wherein the Lentinus edodes is exposed to shear during its cultivation. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a divisional of U.S. patent application Ser. No. 11/786,646, filed Apr. 11, 2007, now U.S. Pat. No. 7,928,861 which claims the benefit of U.S. Provisional Application No. 60/792,965, filed Apr. 19, 2006, both of which applications are incorporated herein by reference.
FIELD
The present invention relates to telemetry apparatus and methods of detection used in the oil and gas industry, and more particularly to methods of detecting telemetry waves propagating predominantly along or through coiled tubing or drillpipe or similar.
BACKGROUND
There are three major methods of wireless data transfer from downhole to surface (or vice versa) for oil and gas drilling in use today: mud pulse, electromagnetic and acoustic telemetry. In a typical acoustic telemetry drilling or production environment, acoustic waves are produced and travel predominantly along the metal wall of the tubing associated with the downhole section required to drill the well. The acoustic energy is usually detected by sensitive accelerometers, and sometimes by relatively less sensitive strain gauges. Care needs to be taken about the positioning and coupling of such devices to the tubing in order that the maximum signal energy can be extracted in order to optimize the detection system's signal to noise ratio (SNR). See U.S. Pat. Nos. 5,128,901 and 5,477,505 to Drumheller for a further discussion of this issue.
In the case of jointed pipe drilling, the surface detection system will be attached at some position below the traveling block (see FIG. 1 ), and despite such systems being relatively small (see, for example, U.S. Pat. No. 6,956,791 to Dopf et al.) can cause severe space constraint issues, particularly in the type of oil rigs that utilize top drive motors to turn the drillpipe. In the case of coiled tubing rigs, a similar space constraint arises (see FIG. 2 ) because there is normally very little space available to optimally attach the detection mechanism directly to the coiled tubing. Furthermore, the problem is compounded in the case of coiled tubing in that the coil—to which the accelerometer is beneficially attached—continually moves into or out of the well. The present invention addresses these constraints and seeks to provide novel means by which they may be overcome.
SUMMARY
It is an object of certain embodiments of the present invention to overcome non-optimal constraints of accelerometer positioning in the detection of telemetry waves that are utilized in transferring data from one part of the tubing between a surface drilling rig and the telemetry transmitter. The methods disclosed herein may be applied to mud pulse telemetry applications or acoustic telemetry applications.
Exemplary embodiments of the present invention provide a contact or a contactless system and method for detecting telemetry waves in any of production tubing, jointed drill pipe, coiled tubing drilling, or any downhole apparatus which transmits telemetry waves that cause measurable radial or axial motion of pipe or tubing of the apparatus (collectively “drillstring”).
According to one aspect, there is provided an apparatus for detecting telemetry waves along a drillstring of a rig. The apparatus comprises: a first laser system in optical communication with a material that is moved by the passage of telemetry waves along the drillstring; and a second laser system in optical communication with a reference portion on or nearby a part of the rig which is not significantly moved by the passage of telemetry waves. The combined output of said first laser system and said second laser system provides a measure of the telemetry waves, which can be pressure pulse waves or acoustic waves.
The first laser system can be in optical communication with a fluid surrounding a portion of a drillstring through which telemetry waves pass; in such case the combined output of said first laser system and said second laser system provides a measure of an instantaneous velocity of a reflecting surface in association with said fluid; said instantaneous velocity providing an indicator of a volume change in said fluid in response to the telemetry waves. In this application, the drillstring can be tubing of a coiled tubing rig. The first laser system can also comprise a laser and a floating reflector in the fluid and the second laser system can comprise a laser and a reflector coupled to the reference portion. For example, the reflector can be coupled to a stripper of a coiled tubing rig.
Alternatively, the first laser system can be in optical communication with a portion of the drillstring through which telemetry waves pass, such as piping of a jointed pipe rig. The first laser system can comprise a laser and a collar having a reflective surface. The laser can be coupled to a travelling block of a jointed pipe rig, and the collar can be coupled to a swivel sub of the jointed pipe rig. The second laser system can comprise a laser and a reflector fixed at the reference portion. This laser is coupled to a travelling block of a jointed pipe rig, and the reflector is coupled to a non-rotating kelly spinner of the jointed pipe rig.
Optionally, the first or the second laser system or both are optically coupled to the respective material and reference portion by at least one minor.
According to another aspect, there is provided an apparatus for detecting a plurality of telemetry waves along a drillstring of a rig. The apparatus comprises: a wheel in non-slipping contact with a portion of the drillstring through which telemetry waves pass; and measurement means such as an accelerometer in communication with the wheel and for measuring a characteristic of the wheel's rotation. Axial movement of the drillstring caused at least in part by telemetry waves passing therethrough rotates the wheel.
At least one wheel can be resiliently coupled to a stripper of a coiled tubing rig.
Alternatively, the measurement means can be an or an optical detector. In a first case, the optical detector can be a laser vibrometry system comprising at least one reflector mounted on the wheel and a laser in optical communication with the reflector. In such case, the optical detector can further comprise a beam-bending optical cell optically coupling the laser with the reflector. In a second case, the optical detector can be a differential laser vibrometry system comprising a first laser system in optical communication with the wheel and a second laser in optical communication with a reference portion of a part of the rig through which telemetry waves do not pass.
According to another aspect, there is provided an apparatus for detecting a plurality of telemetry waves along a drillstring of a rig. This apparatus comprises: contact means for contacting a portion of the drillstring through which telemetry waves pass; and measurement means in communication with the contact means such that radial motion of the drillstring portion is measured, wherein the radial movement of the drillstring is caused at least in part by telemetry waves passing therethrough.
The contact means can be a wheel resiliently coupled by an arm to a portion of the drill string through which telemetry waves do not pass. The measurement means can be an optical detector, such as a differential laser vibrometry system comprising a first laser system in optical communication with the arm and a second laser in optical communication with a reference portion of a part of the rig through which telemetry waves do not pass.
An object of certain embodiments of the present invention is to detect the material velocity (or similar parameter) of particles that are caused to move by the passage of an acoustic telemetry wave travelling along the drillpipe or tubing. For example, travelling harmonic acoustic waves propagate in passbands along drillpipe, and the specifics of these passbands are determined by the type of wave and the geometry of the drillpipe (see, for example, U.S. Pat. No. 5,477,505 to Drumheller). Extensional waves will be discussed herein, although it will be readily apparent to one skilled in the art that the present invention applies also to different types of waves (e.g. rotational waves) and different types of pipe (e.g. production tubing). The discussion begins by considering the mechanical plastic deformation of a steel tube as an extensional wave travels along, and this is then used to assess the required sensitivity of the detection means. As a starting point, a reasonable assumption is made that typical modern accelerometers are able to detect power levels (W) down to the one μW level, so the contactless detection means should be at least compatible with this value.
Consider:
W=z V a 2 [1]
where z=tubing impedance and V a =axial material velocity due to the passage of a simple harmonic wave, and
z=ρAc [2]
where ρ=tubing density, A=tubing wall area, c=bar sound speed in steel.
Inserting typical values for steel coiled tubing, thus:
ρ=7800 kg/m 3 ,
tubing outer diameter (OD)=3″,
tubing inner diameter (ID)=2.75″,
c=5130 m/sec
Combining equations 1 and 2 leads to V a =5.9 μm/sec.
This axial material velocity causes a change in the tubing OD as predicted by Poisson's ratio, as follows.
Consider that for a simple wave the relation between axial strain C a and material axial velocity V a is:
ε a =V a /c [3]
Poisson's ratio μ is:
μ=−ε r /ε a [4]
where ε a is the radial strain.
The change in the outer radius of the tubing due to axial strain is:
Δ r=rε r [5]
where r=radius of the tubing.
The radial velocity V r varies according to the frequency f of the propagating axial wave, and using equations 3, 4 and 5 produces:
V r =2 πfΔr =2 πfμV a /c [6]
A suitable frequency value for an extensional wave in coiled tubing is 2500 Hz, thus:
V r =0.2 μm/sec
Thus if one detects the axial changes in material velocity in the outer wall of typical coiled tubing (with the parameters as given above) due to axial wave propagation one must have a device that has sensitivity of better than 5.9 μm/sec. If instead one is constrained to detect the radial changes primarily caused by the plastic deformation in the outer wall of typical coiled tubing due to the change in material axial motion one must have a device that has sensitivity of better than 0.2 μm/sec.
Published values for laser Doppler vibrometer sensitivity (see Polytec Inc., ‘Vibrometry Basics’—‘HSV-2000 High Speed Vibrometer’) are typically 1 μm/sec. Therefore it is reasonable to utilize such devices for the axial detection of acoustic waves, but further enhancement is required to detect radial acoustic waves.
Furthermore, the possible application also extends to mud pulse telemetry. This is because in such telemetry systems the downhole mud pulser creates a pressure wave that travels substantially to the surface through the drilling fluid in the pipe or tubing, creating a stress wave in the walls of the pipe or tubing as it propagates. The stress wave travels along with the pressure pulse and the deformation of the walls can be assessed by means explained as follows. It is well known (see, for instance, Rourke's Formulas for Stress and Strain, 6 th Edition, pub. McGraw Hill) that for relatively thin-walled tube such as drilipipe or coiled tubing, the incremental change in radius is given by:
Δ r=r 2 ΔP/Et [7]
where E=Young's modulus and t=wall thickness.
Inserting r=3 inches, t=0.25 inches, ΔP=100 psi, E=30×10 6 (steel) we find that Δr=3 μm.
Typical pulse amplitudes detected at surface are ˜100 psi. Considering that normally these mud pulses are usually generated in 0.1 seconds, last for 0.5 to 1.5 seconds, and decay in 0.1 seconds, a laser vibrometer would need to detect a radial increase of 3 μm at a velocity of ˜30 μm/second, a stationary period lasting ˜1 second and a radial decrease of 3 μm at a velocity of ˜30 μm/second. As noted before, this range of measurement is well within the capabilities of modern differential laser vibrometers. The optical output would then be converted and filtered by conventional digital signal process techniques to provide a data stream pertinent to the data inherent in the timing of the mud pulses.
It is to be noted that one can also consider the usefulness of this method, not only for surface detection but downhole for range extension (repeater) purposes.
This summary of the invention does not necessarily describe all features of the invention. Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings illustrate the principles of the present invention and exemplary embodiments thereof:
FIG. 1 is a very simplified representation of a jointed drill pipe rig, with many of the relevant pipe handling components indicated, with the intent of showing the available positions for an acoustic wave detector.
FIG. 2 is a similar representation of a coiled tubing rig, again with the intent of showing the available position for an acoustic wave detector.
FIG. 3 shows how the dimensional changes to a section of coiled tubing can be hydraulically amplified so as to change the position of a reflector that is being monitored by a differential optical system.
FIG. 4 a indicates how an accelerometer can be mounted such that it is able to monitor axial extensional acoustic waves travelling along moving coiled tubing while it remains in essentially the same position.
FIG. 4 b indicates how a contactless optical means, such as a laser vibrometry system can assess the axial material velocity of the tubing by replacing the accelerometer of FIG. 4 a with a series of reflectors disposed along the outside of a wheel that rotates as the tubing moves.
FIG. 4 c indicates how a contactless optical means, such as a laser vibrometry system, can assess the radial material velocity of the pipe or tubing by replacing the accelerometer of FIG. 4 a with a reflector or retroreflector disposed on the arm holding a contacting wheel against the pipe or tubing that rotates as the tubing or pipe moves.
FIG. 5 shows how the concepts established in the previous figures can be implemented on a jointed pipe rig such that axial material velocity can be measured via a contactless optical means, such as a laser vibrometry system, by using a reflector mounted on a suitable position on the swivel sub.
DETAILED DESCRIPTION
FIG. 1 illustrates a typical first type of drillstring, namely a jointed pipe rig 1 . A supported traveling block 2 supported by cables is attached to a kelly swivel 3 . The swivel's function is to take in the drilling fluid via the kelly hose 4 while also supporting a rotating structure called a kelly spinner 5 that in turn supports a pipe 6 (the ‘quill’ in a top drive rig, the ‘swivel sub’ in a jointed pipe rig) to which a kelly pipe 7 is screwed. This assembly enables the pipes from the kelly top on down to rotate according to the drilling needs while being connected to other non-rotating devices and structures above. The rotation means in this figure would be implemented by a rotating section of the rig floor (the ‘rotary table’) through which the kelly is constrained to pass and rotate. Other rigs may utilize a motor called a top drive unit. These devices are mentioned briefly here for completeness, but as they have minor relevance to the invention will not be further detailed.
Acoustic waves transmitted from downhole propagate up through the drillpipe 8 , kelly and swivel sub before encountering a major acoustic mismatch formed by the significant dimensional change at the kelly spinner/swivel interface. The junction effectively faints a non-rigid boundary that significantly reflects the acoustic wave. To those skilled in the art it is apparent that this is an optimum position for an axial accelerometer to be placed in order to detect the acoustic waves. In many embodiments the accelerometer is part of a wireless detection system (see, for example, U.S. Pat. No. 6,956,791 to Dopf et al.).
In normal drilling procedures the swivel sub, the kelly and the attached drillpipe will rotate at typically 1 to 3 times per second. The kelly is moved vertically from its full height above the rig floor (˜10 m) to being almost level with the floor. This brings the aforementioned wireless detection system close to the rig crew who are working next to the tubing on the rig floor. Thus it is necessary for safety reasons that such detection means are minimally sized and have virtually no projections. This space and safety issue is heightened on rigs using top drive units because there is much less space to attach the wireless detection system. It is evident that a significant improvement would be achieved if the detection means comprised an optical contactless system.
FIG. 2 is a very simplified view of the components of a second type of drill string, namely a coiled tubing rig. A coil of tubing 10 is led through a conveyancing means (injector) 11 . The tubing exits the injector head 12 just prior to moving down a structure called a ‘stripper’ 13 . The gap 14 between the injector head and the stripper is typically 18 to 24 inches long; it is apparent that this is a suitable place at which to detect the axial acoustic telemetry waves. Unfortunately this gap is often surrounded by other critical components associated with drilling requirements, and thus it is necessary that whatever detectors are used do not interfere with tubing movement nor with adjacent mechanical structures. The present invention helps address these severe size constraints.
FIG. 3 shows a section of coiled tubing 10 within a stripper 13 . The stripper's primary purpose is to contain the wellbore fluids and/or pressure. Specifically, the circumferential seals prevent fluids or gasses from venting to atmosphere. In the exemplary embodiment two such seals 20 , 21 are illustrated whose additional purpose is to constrain a fluid 22 such as water or oil in the annular space between the coiled tubing and the upper portion of the stripper. This fluid is kept at a reasonably constant volume by a filler port 23 . The height of the fluid is determined by a laser system 24 (laser 1 ) that measures height by reflecting off a surface (diffuse or mirror) 25 from a float 26 in the reflector arm 27 .
It is not necessary to incorporate a floating reflector in the reflector arm. For instance, laser 1 can be configured to reflect from the top of the column of fluid (the meniscus) as long as the laser beam's incident/reflecting angles are adequate and there is sufficient difference in the refractive index between the monitoring fluid and the fluid or gas above; this could be accomplished by using oil as the monitoring fluid and air as the material above.
Laser 1 is part of a laser Doppler vibrometer system (see, for instance, ‘Principle of Laser Doppler Vibrometry’ at Polytek.com for a basic explanation) in the illustrated embodiment. Laser 2 28 is employed to implement a differential measurement such that the combined output of laser 1 and laser 2 is a sensitive measure of the instantaneous velocity of the reflecting surface (mirror or diffuse).
While two lasers 24 , 28 are used in this embodiment to implement a differential method, it is evident to one skilled in the art that a single laser split into two beams can serve the same purpose.
As already noted, the reflecting surface motion includes the transformed axial velocity of the pipe wall due to the passage of an acoustic wave. The inherent axial motion conversion to radial motion via Poisson's ratio is used to move the surface of the fluid in the reflector arm. The motion is further amplified by the ratio of the volume of fluid surrounding the pipe to the volume of fluid in the reflector arm, as follows:
The change in the annular volume ΔV of the fluid between the two circumferential seals, the ID of the stripper and the OD of the tubing caused by the tubing's radial increase in diameter from D 29 to D+ΔD is given to an adequate approximation (ignoring quadratic terms) by
Δ V=πHDΔD/ 2 [8]
where H 30 is the distance between the seals.
This volume change is transferred to the reflector arm as manifested by a change in the height of the column of fluid, given by 31 :
Δ h= 4 ΔV/πd 2 [9]
where d is the diameter 32 of the reflector arm.
Thus by combining equations 8 and 9 the hydraulic gain G h is shown to be
G h =Δh/ΔD= 2 H D/Δd 2 [10]
As shown above, if the vibrometer system is capable of measuring an axial velocity V a of ˜6 m/sec, and the radial velocity V r is below its sensitivity, an hydraulic gain of ˜(6/0.2)=30 is required. If in a particular embodiment H=3″, D=3″ we find that we require Δd to be approximately 0.63″. Reducing Δd further will increase the gain, enabling a smaller V r to be measured, but at the cost of increasing noise.
It will be obvious that there will be other significant changes in fluid volume surrounding the pipe, caused, for instance, by pipe non-uniformity along its length, pipe dimensional changes due to changes in internal drilling fluid pressure, temperature, and so on. These changes can be largely offset by monitoring the level of the reflector via the laser system (using a known ranging technique) and compensating with fluid changes via the filler port. Implementation of a suitable level feedback technique will now be readily apparent to one skilled in the art.
The particular advantage of utilizing a laser measurement system, specifically in a mode that provides an output proportional to the target velocity, is that it becomes a simple matter to filter out extraneous motions. In the exemplary embodiment discount gross motions would be discounted due to bulk fluid level changes, retaining only the relatively high frequency velocities associated with the passing of the acoustic wave. This has the effect of significantly increasing the acoustic telemetry detector's SNR, enabling the detection and decoding of data impressed on the acoustic wave.
There are further advantages of using optical measurement systems—for instance, there is no need to be in contact with the actual pipe/stripper assembly. This enables the possibly bulky optical devices to be remote from the small space available around the exposed pipe, and to maintain appropriate monitoring of the reflector arm fluid sensor (laser 1 ) and also the stripper positioning for differential detection (laser 2 ) via the judicious use of mirrors.
FIG. 4 a illustrates how a relatively small wheel 41 can be utilized to extract axial extensional acoustic wave motion from a section of coiled tubing 10 . As indicated in FIG. 2 , there is normally only a small section 14 of exposed tubing available from which to attach a detector such as an accelerometer. The injector 11 that forces the coiled tubing 10 into the stripper 13 forms a mechanically stiff system that does not allow a significant propagation of such waves past the injector head 12 . Measurements show that the mechanical barrier formed by the injector head 12 acts as a rigid boundary. The boundary causes the majority of the upward travelling waves to reflect at this point and travel back toward the source. It is obvious to those skilled in the art that an appropriate place to detect such waves would be to place the accelerometer at a distance of λ/4 down from the head, where λ, is the wavelength. This distance in practical terms is approximated by utilizing the harmonic frequency (2,500 Hz) and the bar speed (5,130 m/s) to suggest that 0.51 m (˜20″) would be appropriate. The available exposed section 14 in most coiled tubing rigs is compatible with this value. It has been ascertained that even in situations where there is not enough room for a 20″ exposure, modifications to the stripper can make available adequate room for the detector described herein. The usual attachment means in the industry are to directly connect an accelerometer oriented axially to the tubing. Because the tubing is in most circumstances either moving into or out of the stripper 13 this approach is generally unworkable. According to the present invention, by contrast, the accelerometer 42 is attached to the side of a simple wheel 41 that is held in non-slipping contact with the pipe via a spring-loaded 43 arm 44 that is attached to some convenient location 45 , such as the top of the stripper. Despite the rotation of the wheel altering the orientation of the accelerometer, as long as the accelerometer is tangentially attached to the wheel the axial motions within the pipe will be faithfully reproduced by the wheel's motion. Indeed, one could even consider a multiple wheel gearing mechanism by which to magnify the rotation of the accelerometer with respect to the axial motions of the pipe. There now remains the problem of sampling the electrical output of the accelerometer while it is rotating. This is readily accomplished—for instance, one could use slip rings to make appropriate sliding contacts, or one could use a wireless (RF) link 46 . The wheel can be any stiff material with dimensions that provide low inertia (such as aluminium), as long as it does not slip and does not significantly change the impedance of the tubing at the point of contact.
FIG. 4 b represents a modification of the non-slipping wheel 41 as depicted in FIG. 4 a , but with the accelerometer 42 and RF link 46 replaced by optical means. This has the benefit that in extreme cases where space around the stripper 13 is very limited it is helpful to measure the angular motion of the wheel 41 by a laser vibrometry system (or similar) 24 . In this case it is illustrated how a set of four paddles 47 can be attached to one side of the wheel and used as retroreflectors for the optical system. As the wheel turns it will be obvious that the paddles change angle; thus a mirror surface could be beneficially replaced by corner cube or spherical retroreflective material (such as one of the Scotchlite™ products). For clarity only four such paddles are illustrated, but as would be apparent to one skilled in the art, not only do the paddles change angle but also change vertical and horizontal positions as the rotation proceeds, and this effect can be accommodated by attaching more such paddles. As one paddle moves out of optical range another will move in. During the transition one could interpose a beam-bending optical cell between laser system 24 and the wheel 41 , and it is also apparent that a differential laser vibrometry system would be beneficial, as indicated in FIG. 3 , as would be readily evident to one skilled in the art.
FIG. 4 c illustrates an exemplary embodiment which omits both jacket and accelerometer sensors. This embodiment is relevant to mud pulse telemetry in that optical means are employed to determine the pipe or tubing wall 10 movement associated with the strain imparted to the wall as a result of a propagating downhole pressure pulse. It also shows further optical means laser 1 24 and laser 2 28 that may be used to enhance accuracy via differential detection, whereby laser 1 detects motion of the section of the spring-loaded 44 that follows the radial motion of the wheel 41 that is pressed against the pipe or tubing. The principle illustrated by this embodiment is that a travelling pressure wave generated by a downhole mud pulse telemetry system produces stress waves in the wall of the pipe or tubing containing the pulser. These stress waves plastically defoim the pipe, the defoimations manifesting as pipe wall movement coincident with the passage of the pressure wave. Modern laser vibrometers are capable of detecting such changing movements and thus the pipe or tubing via motion of a reflector or retroreflector 46 , in a differential mode using a reflector or retroreflector 47 thereby and achieving a viable telemetry sensor alternative to accelerometers.
It will be obvious to one skilled in the art that this method readily extends to jointed pipe rigs.
FIG. 5 shows an embodiment applicable to the setting of FIG. 1 , wherein a laser vibrometer system is implemented with the purpose of contactlessly and differentially monitoring the axial material motion of the acoustic telemetry waves. The travelling block 2 supports a primary laser system (laser 1 ) 24 that emits and receives laser beams 50 that are aimed at a retroreflecting surface 51 supported by a collar 52 attached to the swivel sub 6 . In this circumstance the laser systems can be safely located well out of the way of the rig crew.
The collar 52 would be placed at an appropriate position on the swivel sub so as to optimally detect the harmonic acoustic telemetry waves, such that reflections at the kelly spinner would not deleteriously affect the combined acoustic signal and reduce its amplitude via destructive interference. The advantage of the collar is not only that it can conveniently be placed at an optimally-receiving position but that it is passive and can be made small and unobtrusive, hardly interfering with normal rig operation. The same can be said for the other retroflector 54 in its role as a differential means.
As the swivel sub and kelly 7 rotate the retroreflecting material will contain at least two axial motions—that due to the material motion in the pipe wall caused by the passage of an acoustic telemetry wave, and that due to minor wobbles of the pipe as it rotates. As previously noted, it is a relatively straightforward matter to filter the latter from the former and improve the SNR. Improvements in the determination of the axial movement due to the acoustic waves are afforded by incorporating a differential measurement, which is implemented by a reference laser vibrometer system 28 (laser 2 ) that is also attached to the travelling block 2 . This system emits and receives laser beams 53 that are targeted to a relatively stationary retroreflector 54 supported on a block 55 that is firmly attached to the non-rotating kelly spinner 5 . As would be appreciated by those skilled in the art, rig motion determined by laser 2 is subtracted from rig motion plus acoustic wave motion determined by laser 1 , thus leading to an improved SNR associated with the movement due solely to the acoustic wave travelling along the drillpipe, the kelly and finally the swivel sub.
It is also evident that the laser systems could be located quite independently of the travelling block and associated machinery. Indeed, they could be attached to the rig floor or superstructure and the laser beams 50 and 53 could be aimed as appropriate via mirrors.
Furthermore, it will now be evident that the laser systems could also assess the material movements of two retroreflecting surfaces (as 51 ). The usefulness in this case is that it is possible to separate the two surfaces in order that the relative phase difference between them due to their separation while being moved by the passage of an acoustic wave would enable subsequent discrimination of upward-travelling waves and downward-travelling waves (i.e. detection via a phased detector array).
Furthermore, it will now be obvious that the optical system, though preferably stationary, need not be so. It could be attached to surface rotating members (generally tubulars) such as the swivel sub. The information gathered could then be recorded or wirelessly retransmitted, or even transferred via slip rings.
It will be apparent that the embodiment shown in FIG. 5 can be adapted to detect pressure waves as produced by mud pulse telemetry. While the embodiments described herein are primarily for acoustic wave telemetry embodiment (extensional waves that travel primarily in the wall of the drillpipe), it will be straightforward to one skilled in the art from such a description to provide embodiments for detecting pressure waves that travel primarily along the drilling fluid constrained by the drillpipe, particularly as the radial extension of the pipe due to the passage of a travelling pressure pulse also creates an axial pipe extension (Poisson effect) that can be similarly monitored by a laser vibrometer system.
One or more currently preferred embodiments have been described by way of example. It will be apparent to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as defined in the claims. | Non-contacting means of measuring the material velocities of harmonic acoustic telemetry waves travelling along the wall of drillpipe, production tubing or coiled tubing are disclosed. Also disclosed are contacting means, enabling measurement of accelerations or material velocities associated with acoustic telemetry waves travelling along the wall of the tubing, utilizing as a detector either a wireless accelerometer system or an optical means, or both; these may also be applied to mud pulse telemetry, wherein the telemetry waves are carried via the drilling fluid, causing strain in the pipe wall that in turn causes wall deformation that can be directly or indirectly assessed by optical means.
The present invention enables detection of telemetry wave detection in space-constrained situations. The invention also teaches a substantially contactless method of determining the time-based changes of the propagating telemetry waves. A final benefit of the present invention is that it demonstrates a particularly simple contacting means of directly measuring wall movements in live coiled tubing drilling environments. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/527,314, filed on Dec. 5, 2003. The disclosure(s) of the above application(s) is (are) incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] End cones for exhaust conversion assemblies, otherwise referred to herein as hot end systems, employing catalytic converters increasingly require accommodations for thermal heat management. One of the chief functions of the end cones is to transition the diameter from the inlet/outlet pipes to the diameter of the substrate and to evenly distribute the exhaust gas over the face of a catalytic converter substrate. In so doing, the end cones are invariably subjected to extreme exhaust gas impingement, high exhaust gas flow velocities and temperatures.
[0003] If the design geometry is not optimized, turbulence invariably occurs which accelerates the heat transfer from the exhaust stream into the end cones. These facts have several detrimental effects to the durability of the converter. Most significant is the exhaust heat has a direct path from the end cone into the main body (container) of the converter, thus raising the exterior temperature of the container and mounting mat. The mounting mat is designed to hold the substrate by “taking up” and limiting the thermal growth differential between the converter housing and the substrate. One way it accomplishes this is by insulating the converter housing, otherwise known in the art as the converter can, from the hot substrate thus lowering the temperature of the can and limiting its thermal growth. The mat is under compression, which with its friction provides the holding force for the substrate and expands to fill the gap differential between the substrate and can caused by their differing thermal growths. Therefore, any mechanism that increases the can temperature is detrimental to the converter durability as it will increase the gap between the can and substrate, which decreases the holding force, imparted by the mat and raises the overall mat temperature reducing its life. Other detrimental effects in more extreme cases are from erosion of the end cones due to exhaust gas impingement and thermal heat loss of the exhaust gas before it reaches the substrate causing increased lit off times and reduced conversion efficiency.
DISCUSSION OF PRIOR ART
[0004] Currently known end cones use rolled and formed stainless steel for both inner and outer cones. Further, such end cones do not employ air gaps and/or insulation in the manner described in the present invention.
[0005] Still other prior art employs cast-in heat shields that require special casting processes that may be prohibitively expensive. The construction of various known end cone assemblies are unduly complicated and often require welding with expensive alloys to accomplish a robust weld.
SUMMARY OF THE INVENTION
[0006] The present invention relates to exhaust system end cone assemblies comprising an outer end cone and an insertable inner end cone which is disposed within the outer end cone in at least partially spaced relationship to provide a gap between the inner and outer end cones. The air gap, which serves as a thermal barrier, optionally including thermal insulation, protects the cast iron end cone and converter housing from extreme temperatures and may eliminate the need for external heat shields to protect other under hood components. More particularly, the present invention describes a way of capturing an inner cone, made of heat resistant material, in a way that requires no welding, crimping or fastening in a conventional way.
[0007] The inner cone is not called upon to have great strength, it only needs to have enough strength to support itself and some light insulation. Therefore a fairly light section is usually all that's required, which helps improve thermal inertia. Its main function is to protect the outer cone from direct exhaust gas impingement lowering its temperature and therefore reducing the heat transfer into the main body of the converter.
DESCRIPTION OF THE FIGURES
[0008] FIG. 1 is a sectional view of an exhaust system end cone assembly embodiment including an insertable inner cone according to the teachings of the present invention;
[0009] FIG. 2 is a cross-sectional view taken along line 2 - 2 of FIG. 1 ;
[0010] FIG. 3 is a cross-sectional view demonstrating an alternative outer end cone flange design taken along the same cross-section as line 2 - 2 ;
[0011] FIG. 4 is a partial cross-sectional view of the outer end cone flange design of FIG. 3 including an inner end cone having outwardly projecting beads;
[0012] FIG. 5 is a sectional view of an alternative exhaust system end cone assembly according to the teachings of the present invention; and
[0013] FIG. 6 is a cross-sectional view taken along line 6 — 6 of FIG. 5 absent the inner end cone.
DETAILED DESCRIPTION OF THE INVENTION
[0014] A catalytic converter end cone assembly 10 having a dual wall air gap for improved thermal heat management is illustrated in FIG. 1 . While the end cone assembly described herein is considered to be applicable to either the inlet side or outlet side of a catalytic converter assembly, as should be appreciated by those of ordinary skill in the art reference will now be made to an inlet end application for purposes of describing the invention.
[0015] The end cone assembly 10 includes an outer end cone 12 which transitions the inner diameter between the catalytic converter housing 16 and an exhaust gas inlet portion 14 . The end cone of the inlet side is intended to assist in evenly distributing the exhaust gas over the face of the catalytic substrate 18 contained within the converter housing that filters the exhaust gases. The inlet portion 14 , shown in the form of a transition pipe may include a flange 24 provided along one end 22 for mounting the catalytic converter end cone assembly to other components such as an exhaust manifold (not shown) by way of non-limiting example. The pipe 14 may also include one or more apertures 26 for hosting exhaust gas monitoring sensors (not shown).
[0016] At an opposite end 28 , the pipe 14 transitions to the outer end cone 12 wherein the internal diameter of the end cone expands to the transition point 30 of the converter housing 16 . As shown, the internal diameter of the outer end cone has a substantially fluted shape. The pipe 14 , outer end cone 12 and converter housing 16 can be a multiple piece cast assembly or as shown in the form of a one piece casting such as those described in co-pending U.S. patent application Ser. No. 10/812,009 entitled “One Piece Catalytic Converter Housing With Integral End Cone”, which is hereby incorporated by reference. Among the preferred alloys for casting are those known in the art as SiMo cast iron alloys.
[0017] The end cone assembly 10 includes means for cooperatively securing the insertable inner cone 44 within the outer end cone 12 . As depicted in FIG. 1 , such means include an inwardly extending flange 36 disposed in proximity to the transition point 30 between the outer end cone 12 and converter housing 16 . The flange 36 which is typically a cast in feature generally includes a shelf 38 and an inner wall 40 . The flange 36 may be continuous as depicted in FIG. 2 or intermittent including various flange sections 36 a as depicted in FIG. 3 . The inner end cone 44 may optimally include outwardly projecting leads 62 which engage the corners 66 of the intermittent flange sections 36 a which prevent the inner core from rotating within the outer end cone 12 .
[0018] The inner cone 44 , which is formed from a heat resistant material such as 439 or 409 stainless steel or ceramics by way of non-limiting example, is sized and shaped to fit within the outer cone 12 . More particularly, the second end 48 of the inner cone 44 as shown in FIG. 1 , is sized to fit securely against the inner wall 40 of the inwardly projecting flange 36 provided along the inner wall of the outer cone or is sized to fit securely against the inner wall sections 40 a of the flange sections 36 a of the embodiment of FIG. 3 . The second end 48 also includes an outwardly extending lip 56 which rests upon the shelf 38 and is captured, i.e., entrapped along an end 60 of the mounting mat 58 upon full insertion into the converter housing 16 .
[0019] At the opposite end 46 the inner cone 44 is sized to seat against the inner wall 34 of the outer end cone 12 . The body 50 of the inner cone diverges from the second end 48 toward the first end 46 such that an air gap 52 is provided between the inner wall 34 of the outer end cone and the outer wall 54 of the inner end cone 44 . Except for connection points along the ends 46 , 48 and the inner cone the air gap is preferably continuous to minimize heat transfer to the outer end cone. The spacing between the inner wall of the outer end cone and the outer wall of the inner end cone may vary between the first and second ends 46 , 48 but on average should be a distance of at least about 2 mm over the length of the assembly. Depending upon the thermal requirements of the end cone assembly 10 , insulation 66 may be provided within the air gap for enhanced thermal dispersion. The insulation can be selected from various known insulation materials but a preferred type of insulation includes ceramic fibers. In addition to effective thermal properties, ceramic fiber insulation tends to dampen vibration.
[0020] Referring to FIG. 5 , an alternative exhaust system end cone assembly employing a snap fit inner end cone 144 is presented. Under this embodiment, the inner end cone 144 includes a circumferential recess 162 which is engaged by the intermittent inwardly projecting flange sections 136 a shown most clearly in FIG. 6 . The flange sections 136 a are substantially rounded to mimic the contour of the recess 162 . Essentially all other elements of the assembly remain the same as described above with reference to FIGS. 1-4 .
[0021] Since the inner cone does not need to function as a structural member of the end cone assembly per se, the inner cone 44 generally only needs enough strength to support itself and some light insulation. Thus, the average thickness of the inner cone 44 , when formed from a lightweight stainless steel is typically less than about 1.4 mm, and preferably is between about and 0.8 mm and 1.25 mm. As should now be appreciated, the primary functions of the inner cone are to protect the outer cone from direct exhaust gas impingement thereby lowering its temperature, reducing the heat transfer into the main body of the converter, reducing overall temperature of the main body and mat, and enhancing durability.
[0022] The inner cone allows for the outer cone (the main structural piece) to be cast and provide for a gap between the inner and outer cones. The gap can host thermal insulation, which may further protect the cast iron from extreme temperatures. This also protects the exterior of the converter from radiating extreme temperatures and may eliminate the need for external heat shields to protect other under hood components.
[0023] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | The present invention relates to an exhaust end cone assembly including an outer end cone which is formed from a cast iron alloy and an inner end cone disposed within the outer end cone which is formed from a heat resistant material. The inner end cone is shaped such that an air gap occurs along a significant portion of the area between the inner and outer end cones to provide thermal advantages to the assembly. | 5 |
FIELD OF THE INVENTION
This invention relates generally to movable partitions or walls such as in a building structure and is particularly directed to a multi-section roll-up curtain assembly.
BACKGROUND OF THE INVENTION
Flexible doors of the general type wherein a drive mechanism for raising and lowering the door includes an electrically powered motor which applies torque to a roller causing the door to wind up on or to unwind from the roller in positioning the door in either the open or closed position, or any position therebetween. The flexible curtain is typically comprised of a lightweight, strong fabric material and the electric motor is typically connected to the roller mechanism via a reduction gear to reduce the number of revolutions of the electric motor per unit distance of travel of the flexible door. Movable structures of this type can be used either to cover an opening, such as a doorway in a building structure, or they be used as a movable partition, or curtain, in the structure.
When used as a partition, or curtain, this roll-up structure may span large distances in the building structure. These types of flexible curtains isolate the inside of the building structure from the elements, such as wind, rain, snow and sunlight, while permitting the building structure to be opened up so as to provide access to the outside when the environment is more hospitable.
As the applications for these types of flexible curtains have increased, additional demands have been placed on their structure and operation. For example, these types of flexible curtains are being used to span increasingly longer distances within the building structure. This, of course, places increasing demands upon the curtain support and drive, or displacement, system. Higher power ratings are required for the curtain drive mechanism, which typically includes an electrically powered motor, for increasing heights and horizontal distances spanned by the curtain. In addition, the curtain support system, which typically is in the form of a horizontal, elongated rod, must be stronger to accommodate the increased weight of curtains spanning larger openings and must itself be lightweight to compensate for the increased weight of the curtain. This further increases the power requirements to operate the flexible curtain. Where a roll-up rod is attached to a lower end of the flexible curtain, a complicated displacement and support mechanism is typically required to accommodate vertical movement of the rod.
The present invention addresses the aforementioned limitations of the prior art by providing a multi-section roll-up curtain assembly including plural, vertically spaced, horizontal roll-up rods each extending across an opening and attached to a respective section of the curtain. Each of the rods is coupled to and rotated by a respective electric motor, with the electric motors connected and vertically displaced with the curtain either upward or downward in retracting or extending the curtain sections in unison.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a multi-section roll-up curtain for use as a partition or wall in a building structure which is capable of spanning a large distance.
It is another object of the present invention to provide a multi-section roll-up curtain including plural bi-directional drive motors coupled together and arranged in a vertically spaced manner, with each motor coupled to a respective curtain section to permit the motors and curtain sections to move upward or downward in unison in opening or closing the curtain.
Yet another object of the present invention is to reduce the power required to operate a large roll-up curtain covering a large horizontal span and height.
A further object of the present invention is to incorporate plural vertically spaced, elongated horizontal members in a roll-up curtain to strengthen the curtain and make it more resistant to wind damage without increasing the power required to open and close the curtain.
The present invention contemplates a roll-up curtain comprising a first curtain section including a first fixed upper rod attached to a support structure and a second lower rod; a second curtain section in vertical alignment with the first curtain section and including a third fixed upper rod attached to the support structure and a fourth lower rod, wherein the second curtain section is disposed below the first curtain section; a first rotary drive coupled to the second lower rod for rotationally displacing the second lower rod in a first direction for rolling up the first curtain section onto the second lower rod, wherein the second lower rod is displaced upward toward first fixed upper rod in opening the first curtain section, or for rotationally displacing the second lower rod in a second opposed direction for unrolling the first curtain section from the second lower rod in closing the first curtain section; a second rotary drive disposed below the first rotary drive and coupled to the fourth lower rod for rotationally displacing the fourth lower rod in a first direction for rolling up the second curtain section onto the fourth lower rod, wherein the fourth lower rod is displaced upward toward the third fixed upper rod in opening the second curtain section, or for rotationally displacing the fourth lower rod in a second opposed direction for unrolling the second curtain section from the fourth lower rod in closing the second curtain section; and a coupling arrangement for connecting the first and second rotary drives wherein the first and second rotary drives move upward in unison when the second and fourth lower rods are displaced upward in opening the first and second curtain sections, and wherein the first and second rotary drives move downward in unison when the second and fourth lower rods are displaced downward in closing the first and second curtain sections.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which:
FIG. 1 is a perspective view of a roll-up curtain assembly in accordance with the present invention shown in the full closed position;
FIG. 2 is a perspective view showing the roll-up curtain assembly of FIG. 1 in a partially open position;
FIG. 3 is a perspective view of a support and drive arrangement for raising and lowering the roll-up curtain assembly of the present invention;
FIG. 4 is a partial perspective view of plural curtain sections of a roll-up curtain assembly in accordance with one embodiment the present invention;
FIG. 5 is a side elevation view shown partially in section of a multi-section, roll-up curtain assembly in accordance with the present invention;
FIG. 6 is a partial sectional view of a portion of a support structure for use with the roll-up curtain assembly of the present invention;
FIG. 7 is a plan view of a pair of drive motors each connected to a respective moveable support rod attached to a respective curtain section for raising and lowering the curtain sections in unison; and
FIGS. 8 and 9 are respectively exploded and perspective views of a drive mechanism for raising and lowering a roll-up curtain assembly in accordance with one aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , there is shown a perspective view of a roll-up curtain assembly 10 in accordance with the present invention shown in the extended, or closed, position. FIG. 2 is a perspective view of the inventive roll-up curtain assembly 10 in the retracted, or upraised, position.
The roll-up curtain assembly 10 includes an upper curtain 12 and a lower curtain 14 . The upper and lower curtains 12 , 14 are connected to and supported by first and second spaced support columns 28 and 30 . The first and second support columns 28 , 30 respectively include upper mounting brackets 28 a and 30 a for attaching the support columns to upper frame members in the building structure within which the roll-up curtain assembly 10 is installed. The first and second support columns 28 , 30 are also provided with respective lower mounting brackets, 28 b and 30 b for attaching the support columns to an upward extending edge 16 a of the building structure's base, or floor, 16 . The building structure itself within which the roll-up curtain assembly 10 is installed is not shown in the figures for simplicity.
Respective upper edges of the upper and lower curtains 12 , 14 are each provided with a hem. Inserted within the upper hem of the upper curtain 12 is a first rod 18 , while inserted through the upper hem of the lower curtain 14 is a second rod 20 . Each of the first and second rods 18 , 20 is fixedly coupled to the first and second curtain support columns 28 and 30 by conventional means such as mounting brackets which are described below. The lower edge of the upper curtain 12 is also provided with a hem in which is inserted a third rod 22 . Similarly, an intermediate portion of the lower curtain 14 is provided with a hem into which is inserted a fourth rod 24 . Finally, the lower edge of the lower curtain 14 is provided with a hem into which is inserted a fifth rod 26 . Each of the rods is preferably comprised of a high strength, lightweight material such as aluminum or plastic and extends the full length of the curtain within which it is disposed. In addition each of the rods is preferably in the form of a hollow tube to reduce its weight. In the embodiment shown in FIGS. 1 and 2 , the lower curtain 14 includes an upper section 14 a disposed between the second and fourth rods 20 , 24 and a lower section 14 b disposed between the fourth rod and the fifth rod 26 . However, this invention is not limited to this configuration, as both curtains may include only a single section, both curtains may include plural sections, or the roll-up curtain assembly may include more than two vertically aligned roll-up curtains in accordance with the principles of the present invention.
The ends of each of the upper and lower curtains 12 , 14 are further connected to a support-drive mechanism 40 which is shown in greater detail in the perspective view of FIG. 3 . Support/drive mechanism 40 includes a support frame 42 comprised of first and second vertical side frame members 42 b and 42 c and an upper frame member 42 a connecting the upper ends of the side frame members. A lower frame member 42 d connects adjacent lower ends of the first and second side frame members 42 b, 42 c. Support/drive mechanism 40 further includes third and fourth side frame members 50 a and 50 b disposed adjacent to and spaced from the first and second side frame members 42 b and 42 c, respectively. The space between the first and third side frame members 42 b, 50 a forms a first retainer slot 51 a, while the space between the second and fourth side frame members 42 c and 50 b forms a second retainer slot 51 b. Disposed within the first retainer slot 51 a are respective ends of the third rod 22 and the fourth rod 24 (shown in dotted line form in FIG. 3 ). Inserted through the second retainer slot 51 b are sixth and seventh rods 36 and 38 also shown in dotted line form in FIG. 3 . The sixth and seventh rods 36 , 38 are respectively coupled to adjacent upper and lower curtains 32 and 34 which are not shown in FIG. 3 for simplicity, but are shown in FIGS. 1 and 2 . Each of the aforementioned rods is freely movable within its associated retainer slot as the upper and lower curtains are displaced upwardly or downwardly within the support frame 42 as described in the following paragraphs. First, second, third and fourth cover panels 44 a, 44 b, 44 c and 44 d extend between and are coupled to the first and second side frame members 42 b and 42 c. A first upper mounting bracket 46 a is coupled to respective upper ends of first side frame member 42 b and third side frame member 58 a. Similarly, a second upper mounting bracket 46 b is connected to respective upper ends of second side frame member 42 c and fourth side frame member 50 b. The first and second upper mounting brackets 46 a, 46 b are further coupled to the upper frame member 42 a of the frame support 42 and facilitate attaching the support/drive mechanism 40 to an upper portion of the building structure within which the roll-up curtain assembly is installed.
Attached to adjacent ends of third rod 22 and sixth rod 36 by means of a first drive shaft 54 a is an upper motor/gearbox combination 52 a. Similarly, attached to adjacent ends of fourth rod 24 and seventh rod 38 by means of a second drive shaft 54 b is a lower motor/gearbox combination 52 b. Rotation of the third rod 22 by the upper motor/gearbox combination 52 a causes the upper curtain 12 to be either rolled-up unto or unrolled from the third rod in raising or lowering the upper curtain. Similarly, rotation of the fourth rod 24 by means of the lower motor/gearbox combination 52 b causes the lower curtain 14 to be rolled-up on or unrolled from the fourth rod. Similarly, rotation of the sixth rod 36 by means of the upper motor/gearbox combination 52 a and rotation of the seventh rod 38 by means of the lower motor/gearbox combination 52 b causes respective curtains attached to these rods to be either retracted or extended. The upper and lower motor/gearbox combinations 52 a, 52 b are coupled by means of connecting bar 56 so that the two motor/gearbox combinations and rods connected thereto move in unison either upward in rolling the curtain section up to the retracted position or downward in unrolling the curtain sections from the supporting rods and moving the curtain to the fully extended, or closed, position.
Additional details of the roll-up curtain is shown in the partial perspective view of FIG. 4 . As previously described, the upper curtain 12 includes an upper hem 12 a within which is inserted the first rod 18 . Upper curtain 12 further includes a lower hem 12 b within which is inserted the third rod 22 . Similarly, lower curtain 14 includes upper, intermediate and lower hems 58 a, 58 b and 58 c within which are respectively disposed the second, fourth and fifth rods 20 , 24 and 26 . A pair of threaded coupling pins 70 a and 70 b fixedly attach the third rod 22 to the lower hem 12 b of the upper curtain 12 . Thus, when the third rod 22 is rotationally displaced, the upper curtain 12 is either rolled up onto or is unrolled from the third rod. Similarly, threaded couplers are used to fixedly attach the fourth rod 24 to the intermediate hem 58 b of the lower curtain 14 to ensure that when the fourth rod is rotationally displaced, the upper and lower sections 14 a and 14 b of the lower curtain 14 are either rolled up onto or unrolled from the fourth rod. Attached to the fifth rod 26 as well as to the lower hem 58 c of the lower curtain 14 is a protective sleeve 60 . Protective sleeve 60 is attached to the fifth rod 26 and the lower hem 58 c by means of threaded coupling pins 62 a and 62 b. Protective sleeve 60 is preferably comprised of a lightweight, semi-rigid and durable material such as PVC to afford protection for the lower edge of the curtain. Also shown is the manner in which drive shaft 54 b is securely coupled to an end of the fourth rod 24 . The narrowed end of the drive shaft 54 b is telescopically inserted in an adjacent end of the fourth rod 24 and the connection between these shafts is maintained by means of threaded coupling pins 68 a and 68 b. A similar connection arrangement to an upper drive shaft is provided for attaching the drive shaft to the third rod 22 , but details of this connecting arrangement are not shown in FIG. 4 for simplicity.
Referring to FIG. 5 , there is shown a side elevation view of additional installation details of a roll-up curtain assembly 80 in accordance with the principles of the present invention. As in the previously described embodiment, roll-up curtain assembly 80 includes an upper curtain 82 and a lower curtain 84 . Upper and lower edges of the upper curtain 82 are provided with respective hems, with a first rod 86 inserted in the upper curtain's upper hem and a second rod 88 inserted through the upper curtain's lower hem. Opposed ends of the first rod 86 are inserted in and supported by pipe hanger brackets 118 disposed on adjacent support frames 112 . As described above, the second rod 88 is coupled to a drive mechanism for rotational displacement of the second rod in raising or lowering the upper curtain 82 .
The lower curtain 84 is comprised of an upper curtain section 84 a and a lower curtain section 84 b. An upper edge of the upper curtain section 84 a is provided with a hem along the length thereof into which is inserted a third rod 90 . Similarly, the lower end of the lower curtain section 84 b is provided with a hem into which is inserted a fifth rod 94 . An intermediate portion of the lower curtain 84 is provided with a third hem into which is inserted a fourth rod 92 . Opposed ends of the fourth rod 92 are connected to a drive mechanism for rotationally displacing the fourth rod in either raising or lowering the lower curtain 84 as previously described. Opposed ends of each of the aforementioned rods are disposed within a slot 103 formed between the support frame 112 and a curtain retainer track 102 . Slot 103 maintains all of the aforementioned rods in a generally common vertical alignment during retraction and extension of the curtain as well as when the curtain is in a fixed position. A lower end of the support frame 112 is securely mounted to a concrete base 110 by means of nut and bolt combinations 122 a and 122 b. Similarly, a lower end of the curtain retainer track 102 is securely mounted to the concrete base 110 by means of the combination of a lower angle 106 and a mounting screw 108 . Upper ends of the curtain retainer track 102 and support frame 112 are securely attached to a roof structure 96 by means of respective first and second upper mounting brackets 104 and 114 . Roof section 96 includes plural spaced rafters 98 a and 98 b as shown in the partial sectional view of FIG. 6 and plural spaced purlins 100 a, 100 b and 100 c as shown in FIG. 5 . An optional fixed curtain 124 may be attached to the second purlin 100 b by means of a mounting bracket 106 . A lower edge of the fixed curtain 124 is provided with a hem for receiving a sixth rod 128 which maintains the fixed curtain in a vertical, stretched configuration as shown in FIG. 5 .
Additional details of the manner in which an upper end of the curtain retainer track 102 is securely attached to the roof structure 96 are shown in FIG. 6 . Disposed on opposed sides of the curtain retainer track 102 and attached to the upper edge thereof by conventional means such as a glue or cement composition are the aforementioned upper mounting bracket 104 a and a second upper mounting bracket 104 b. Upper mounting brackets, or straps, 104 a, 104 b are also attached to a pair of side-by-side roof rafters 98 a and 98 b. A first mounting screw 130 a is inserted through upper mounting bracket 104 a and roof rafter 98 a for connecting these members, while a second mounting screw 130 b is inserted through upper mounting bracket 104 b and roof rafter 98 b for securely connecting these structural members. Upper portions of the roof rafters 98 a, 98 b, which each have a generally C-shaped cross section, are connected to roof purlin 100 a by conventional means such as connecting screws or brackets, which are not shown in the figure for simplicity.
Referring to FIG. 7 there is shown a plan view of another embodiment of a curtain drive mechanism 140 in accordance with the principles of the present invention. FIGS. 8 and 9 are respectively exploded and assembled perspective views of a double reduction drive mechanism 210 employed in the curtain drive mechanism 140 of FIG. 7 .
Curtain drive mechanism 140 includes an upper double reduction drive mechanism 146 and a lower double reduction drive mechanism 170 . Upper double reduction drive mechanism 146 includes a first electric motor 148 , a first gearbox 150 , and first and second paired sprockets, or tooth gears, 152 and 154 . The first paired sprockets 152 are connected to and rotationally drive a first drive rod 156 while the second paired sprockets 154 are coupled to and rotationally displace a second drive rod 158 . The first drive rod 156 is disposed in a first vertical slot formed by a first curtain retainer track 142 and a first support frame (not shown), while the second drive rod 158 is disposed in a second vertical slot formed by a second curtain retainer track 144 and a second support frame (also not shown). The first and second drive rods 156 , 158 are displaced vertically within a respective slot by operation of the upper and lower double reduction drive mechanisms 146 , 170 as in the previously described embodiment. An electrical lead 160 is coupled to and provides input power to the first electric motor 148 .
The lower double reduction drive mechanism 170 similarly includes a second electric motor 172 , a second gearbox 174 , and third and fourth paired sprockets 176 and 178 . The third paired sprockets 176 are coupled to and rotationally displace a third drive rod 180 , while the fourth paired sprockets 178 are coupled to and rotationally displace a fourth drive rod 182 . An electrical lead 184 is connected to and provides input power to the second electric motor 172 . Each of the third and fourth drive rods 180 , 182 is inserted in a respective slot formed partially by the first and second curtain retainer tracks 142 , 144 and are displaced vertically within the slots by operation of the second electric motor 172 .
The upper and lower double reduction drive mechanisms 146 and 170 move vertically in unison because they are connected together in the following manner. Attached to the first electric motor 148 by plural connecting pins such as screws is a first mounting plate 162 . Similarly, attached to the second electric motor 172 by plural connecting pins is a second mounting plate 186 . The first mounting plate 162 is connected to respective upper ends of first and second connecting shafts 164 and 166 , while the second mounting plate 186 is coupled to respective upper ends of third and fourth connecting shafts 188 and 190 . Each of the aforementioned shafts is connected to a respective mounting plate by conventional means such as a threaded connecting pins and a mounting bracket which are not shown in the figure for simplicity. Coupling the lower end of the first connecting shaft 164 to the upper end of the third connecting shaft 188 is a first connecting rod 192 while connecting the lower end of the second connecting shaft 166 to the upper end of the fourth connecting shaft 190 is a second connecting rod 194 . Each of the aforementioned first and second connecting rods 192 , 194 is coupled to a pair of connecting shafts by conventional means such as a set screw or connecting pin (also not shown for simplicity). By thus connecting the upper and lower double reduction drive mechanisms 146 and 170 , the two drive mechanisms move upwardly and downwardly in unison and upper and lower curtains respectively attached to the upper and lower double reduction drive mechanism also move upwardly and downwardly towards the open and closed positions, respectively, in unison.
Referring to FIGS. 8 and 9 , the details of the configuration and operation of each of the double reduction drive mechanisms will now be described. Shown in FIGS. 8 and 9 respectively in exploded and assembled perspective views is a double reduction drive mechanism 210 as used in one embodiment of the present invention. Double reduction drive mechanism 210 allows larger curtain spans and heights to be accommodated without increasing the input power required to move the curtains between the open and closed positions by increasing the torque applied to the curtain sections. In addition, the double reduction drive mechanism decreases the speed of the curtains being raised or lowered without increasing the speed or power of the drive motor.
Double reduction mechanism 210 includes an electric motor 212 connected to a gearbox 214 . Gearbox 214 changes the drive axis from a generally vertical orientation to a horizontal orientation as evidenced by the position of the first and second drive shafts 216 a and 216 b extending from an upper portion of the gearbox. The first and second drive shafts 216 a, 216 b are respectively inserted within an aperture of and connected to first and second drive sprockets 232 a and 232 b. The first and second drive sprockets 232 a, 232 b are coupled to the first and second drive shafts 216 a, 216 b, respectively, by conventional means such as a shaft keyed or a threaded set screw. Engaging the first and second drive sprockets 232 a and 232 b are first and second roller drive chains 230 a and 230 b, respectively. The first drive chain 230 a further engages the teeth of a first driven sprocket 228 a, while the second drive chain 230 b engages the teeth of a second driven sprocket 228 b. Each of the first and second driven sprockets 228 a, 228 b includes a respective aperture within which is inserted a respective end of a connecting rod 224 . Connecting rod 224 is inserted through aligned first and second brass bushings 222 a and 222 b and a spacer rod 220 disposed between the brass bushings. The first and second brass bushings 220 a, 220 b and the spacer rod 220 are maintained in fixed, spaced position along the length of the connecting rod 224 by means of first and second locking keys 226 a and 226 b inserted in respective slots in the connecting rod. Rotation of the drive shafts 216 a and 216 b in a first direction causes a corresponding rotation of the drive chains 230 a, 230 b, the driven sprockets 228 a, 228 b and the connecting rod 224 , while rotation of the drive shafts in a second, opposed direction results in reverse rotation of the aforementioned components of the double reduction drive mechanism 210 which are connected to the drive shaft. It is in this manner that the rods which are connected to the connecting rod 224 as well as to a curtain section either roll-up or unroll the curtain section.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art. | A roll-up curtain assembly includes plural, vertically spaced, horizontal roll-up rods extending across an opening. Each roll-up rod is coupled to a respective flexible curtain section and an electric motor. Actuation of the electric motor in a first direction of rotation causes rotation of the roll-up rod in a first direction for rolling the flexible curtain section onto the rod and moving the curtain assembly to the retracted, or open, position. Actuation of the electric motor in a second, opposed direction of rotation lowers the roll-up rod resulting in an unwinding of the curtain section from the rod allowing the curtain assembly to assume the extended, or closed, position. Plural vertically spaced curtain sections each having a respective motor/roll-up rod combination are coupled together and move upward or downward in unison. | 4 |
BACKGROUND
[0001] The present invention generally relates to semiconductor process integration, and more specifically relates to a semiconductor device which has Si-Ge on Silicon and a layer of Si-Ge forms the base of a bipolar transistor and a layer of Silicon on the layer of Si-Ge forms the emitter of the bipolar transistor, and a method of making a semiconductor device where the method includes depositing Si-Ge on Silicon, and the method provides that a layer of Si-Ge forms the base of a bipolar transistor and a layer of Silicon on the layer of Si-Ge forms the emitter of the bipolar transistor.
[0002] The semiconductor industry has been constantly striving to improve the data transfer speed for communications using silicon-based semiconductor devices (i.e., semiconductor products). To date, various schemes and improvements have been proposed, both in the area of process technology and circuit design, in order to handle the higher frequencies required for data transmission with lower power consumption.
[0003] Present semiconductor devices are typically configured such that FET transistors and other devices, such as speed-performance sensitive parts of a circuit, are disposed on Silicon. As such, carrier flow is not forced to a surface channel region. This causes short channel effects, thereby resulting in leakage and/or increased power consumption. Additionally, as transistor sizes shrink, the electron hole carrier mobility and the device noise needs to be improved to provide adequate performance and circuit design margin.
OBJECTS AND SUMMARY
[0004] A general object of an embodiment of the present invention is to provide a semiconductor device which has at least a region that provides Si-Ge on Silicon and a Silicon layer on the Si-Ge, where the semiconductor device is configured such that the Si-Ge forms the base of a bipolar transistor and the Silicon on the Si-Ge forms the emitter of the bipolar transistor.
[0005] Another object of an embodiment of the present invention is to provide a method of making a semiconductor device, where the method includes depositing Si-Ge on Silicon, and the method provides that a layer of Si-Ge forms the base of a bipolar transistor and a layer of Silicon on the layer of Si-Ge forms the emitter of the bipolar transistor.
[0006] Still another object of an embodiment of the present invention is to provide a method of making semiconductor device which eliminates processing steps which are typically required to form an emitter over the base region.
[0007] Still yet another object of an embodiment of the present invention is to provide a semiconductor device which includes a strained silicon layer which provides increased mobility of electrons through the base.
[0008] Yet still another object of an embodiment of the present invention is to provide a semiconductor device which has a thin base region with a high dopant concentration and abrupt doping profiles.
[0009] Another object of an embodiment of the present invention is to provide a semiconductor device which provides retardation in dopant diffusion out fo the base region, caused by the incorporation of dopants near the junction interfaces.
[0010] Another object of an embodiment of the present invention is to provide a method of making a semiconductor device wherein oxygen is incorporated into the base at the emitter to base junction to increase barrier potential and subsequent emitter efficiency of the device.
[0011] Another object of an embodiment of the present invention is to provide a method of making a semiconductor device which consumes less dynamic power due to a higher operating frequency.
[0012] Another object of an embodiment of the present invention is to provide a method of making a semiconductor device which provides that base contact is made by either tungsten plugs or by the use of poly silicon.
[0013] Briefly, and in accordance with at least one of the forgoing objects, an embodiment of the present invention provides a semiconductor device which has at least a region where Si-Ge is disposed on Silicon. Specifically, the semiconductor device preferably includes Si-Ge disposed on a Silicon substrate. The semiconductor device may include a Silicon region which does not include any Si-Ge, but preferably also includes an Si-Ge region which includes Si-Ge on Silicon. Preferably, the Si-Ge is provided as an Si-Ge layer which is disposed between a Silicon layer and the Silicon substrate, and the Si-Ge forms the base of a bipolar transistor and the Silicon layer on the Si-Ge forms the emitter of the bipolar transistor.
[0014] A method of making such a semiconductor device is also provided, and includes steps of forming an oxide layer on a Silicon substrate, masking at least a portion of the oxide layer to define a deep collector implant and N well implants, Vt adjusting the implant to define the CMOS (FET) devices, mask at least a portion of the oxide layer and implant dopant to form a collector region of a bipolar transistor, masking to define one or more selective areas within a chip on which epitaxial Si-Ge and a Silicon layer will be grown, removing (such as by wet etching) at least a portion of the oxide layer in order to expose a portion of the Silicon substrate and create an undercut in open areas defined by the previous masking step, epitaxially growing an Si-Ge layer on the exposed portion of the Silicon substrate, epitaxially growing a Silicon layer on the Si-Ge layer, if regions are not doped then masking and implanting dopant to define the base and emitter regions of the bipolar transistor, and continuing manufacture of the device by forming one or more bipolar and CMOS devices and continuing until the end of the line to define interconnect and passivation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The organization and manner of the structure and operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals identify like elements in which:
[0016] [0016]FIG. 1 is a block diagram of a method which is in accordance with an embodiment of the present invention; and
[0017] [0017]FIG. 2 is a general schematic view of a semiconductor device illustrating one of the steps of the method shown in FIG. 1, wherein layers of Silicon dioxide, Polysilicon (or Silicon nitride), and Silicon nitride (or oxide) are disposed on a Silicon substrate;
[0018] [0018]FIG. 3 is a general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 1, wherein an area where an HBT device is to be formed is defined;
[0019] [0019]FIG. 4 is a general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 1, wherein portions of layers are removed to expose an underlying oxide layer;
[0020] [0020]FIG. 5 is a general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 1, wherein sidewall spacers are formed;
[0021] [0021]FIG. 6 is a general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 1, wherein oxide is removed to form an undercut;
[0022] [0022]FIG. 7 is a general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 1, wherein an Si-Ge layer is formed and a layer of Silicon is formed to provide a base and emitter, respectively;
[0023] [0023]FIG. 8 is a block diagram of a method which is in accordance with another embodiment of the present invention;
[0024] [0024]FIG. 9 is general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 8, wherein layers of Silicon dioxide and Silicon nitride are disposed on a Silicon substrate;
[0025] [0025]FIG. 10 is general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 8, wherein an area where an HBT device is to be formed is defined;
[0026] [0026]FIG. 11 is general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 8, wherein a region of the Silicon dioxide layer is removed and an undercut is formed; and
[0027] [0027]FIG. 12 is general schematic view of a semiconductor device illustrating a subsequent step of the method shown in FIG. 8, wherein an Si-Ge layer is formed and a layer of Silicon is formed to provide a base and emitter, respectively.
DESCRIPTION
[0028] While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, specific embodiments with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as illustrated and described herein.
[0029] [0029]FIG. 1 illustrates, in block diagram form, a method 10 of making a semiconductor device, and FIGS. 2-7 illustrate a semiconductor device 20 being made in accordance with the steps shown in FIG. 1. Both the method 10 of making the semiconductor device 20 and the structure of the semiconductor device 20 itself are embodiments of the present invention.
[0030] Generally, the method 10 shown in FIG. 1 includes the step of depositing Si-Ge on Silicon. As a result, both an Si-Ge region 22 and a Silicon region 24 is formed on the semiconductor device 20 (see FIG. 7). This provides that speed performance sensitive parts of the circuit may be built on the Si-Ge region(s) 22 within the die, while non-speed sensitive designs or legacy designs on Silicon may be implemented in the Silicon region(s) 24 on the chip. This is done by integrating high performance vertical Bipolar transistors in conjunction with high performance CMOS devices on the same chip. While a graded Si-Ge layer forms the base of a bipolar transistor, epitaxial Si grown on top of the graded Si-Ge layer forms the emitter.
[0031] In addition to depositing Si-Ge on Silicon, Silicon is deposited on the Si-Ge. Due to lattice mismatch between Si-Ge and Silicon, the carrier mobility is improved, thereby improving the performance of the semiconductor device. Additionally, the strain causes the carriers to be restricted to the surface Silicon layer. This improves short channel effects thereby reducing leakage and therefore standby power consumption. The method 10 and the semiconductor device 20 itself provides that the Si-Ge forms the base of a bipolar transistor, while the Silicon on the Si-Ge forms the emitter of the bipolar transistor. This structure offers improved device performance because of the seamless crystal transition from the collector to the emitter.
[0032] The method 10 shown in FIG. 1 provides that initially there is standard CMOS process flow up to pattern zero mask layer to define initial alignment marks (box 30 in FIG. 1). Then, a thermal pad is grown and Silicon dioxide is screened (box 40 in FIG. 1) thereby providing layers of oxide 32 , Polysilicon (or Silicon nitride) 34 , and Silicon nitride (or oxide) 36 on a Silicon substrate 38 . Then, Field Isolation definition and subsequent standard processing is continued (box 50 in FIG. 1). Then, regions are defined and the collector, N-well and Vt regions are implanted on the wafer (box 60 in FIG. 1). Then, the MOS transistors are defined (Polysilicon gates with LDD implants, sidewall spacers and source drain implants) (box 70 in FIG. 1). Then, a Silicon nitride layer or any other hard masking material layer that will not interact with a selective epitaxial deposition of Silicon Germanium is deposited (box 80 in FIG. 1). Then, as shown in FIG. 2, a photolithography process is used (hence, a mask 42 is typically employed as shown in FIG. 3) to define the area 44 where an HBT device is to be formed (over the collector region). Then, as shown in FIG. 4, the Silicon nitride layer 36 and Polysilicon 34 is plasma etched to expose the underlying oxide layer 32 (box 90 in FIG. 1). Then, a Silicon nitride layer is deposited and then etched (using a RIE etch) to leave sidewall spacers 46 on the sides of Polysilicon layer as shown in FIG. 5 (see also FIG. 1, wherein box 100 corresponds to this step). Then, as shown in FIG. 6, a portion of the oxide layer 32 is wet etched to remove the oxide and undercut the Polysilicon layer (box 110 in FIG. 1). Then, as shown in FIG. 7, selective epitaxial deposition is used to grow the appropriately doped (preferably n-type for mobility and gain reasons) Si-Ge layer for base region 52 (box 120 in FIG. 1) and Silicon is deposited to provide an emitter 54 , thereby providing an HBT device which includes a Silicon substrate 38 , a base 52 , an emitter 54 , insulating sidewall spacers 46 and Polysilicon for base contact. Then, the wafer is RTP annealed to activate the implants and processing is continued to define interconnect wiring (box 130 in FIG. 1).
[0033] [0033]FIGS. 8-12 depict an alternative approach using Silicon nitride 62 instead of layers of Polysilicon 34 and Silicon nitride 36 , wherein contact to base is made by Tungsten plugs or other metallic contacting material. Specifically, as shown in FIG. 9, a thermal pad is grown and Silicon dioxide is screened on a Silicon substrate 38 , thereby providing layers of Silicon nitride 62 and oxide 32 on the Silicon substrate 38 (box 200 in FIG. 8). Then, as shown in FIG. 10, photolithography is used to define where a HBT device will be placed and the layer of Silicon nitride 62 is etched to expose the Silicon dioxide 32 (box 202 in FIG. 8) (area 63 in FIG. 10). Then, as shown in FIG. 11, a region of Silicon dioxide 32 is wet etched to undercut the Silicon nitride 62 (box 204 in FIG. 8) (area 65 in FIG. 11). Then, as shown in FIG. 12, an Si-Ge base 72 and emitter 74 are grown/deposited (box 206 in FIG. 8), and the process is continued to show the deposition of the intermetal dielectric, tungsten plug ( 76 ) creation (to contact base 72 and emitter 74 ), metal patterning and etch for contact to HBT device (box 208 in FIG. 8). As shown in FIG. 12, preferably the device includes an insulating material 78 , such as Silicon nitride.
[0034] While embodiments of the present invention are shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the appended claims. | A semiconductor device wherein Si-Ge is the base of a bipolar transistor and a Silicon layer is the emitter. A method of making such a semiconductor device including steps of forming a Silicon dioxide layer on a Silicon substrate, using a photo resist application and exposure to define where a HBT device will be placed. Plasma etching the Silicon dioxide layer to define an undercut, epitaxially growing an Si-Ge layer and a Silicon layer, and continuing manufacture to form one or more bipolar and CMOS devices and define interconnect and passivation. | 7 |
REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/722,269 filed on Sep. 30, 2005, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to temperature control systems and, more particularly, to a temperature control system for cargo carriers and a method of operating the same.
SUMMARY
[0003] Some embodiments of the present invention provide a temperature control system for conditioning air in a load space. The temperature control system can include a refrigeration circuit extending between a compressor, an evaporator coil, and a condenser. The temperature control system can also include a controller programmed to control operation of the temperature control system and to regulate the temperature of the load space. The controller can be programmed to operate the temperature control system in a cooling mode, a heating mode, and a defrost mode based, at least in part, on data received from one or more sensors distributed along the refrigeration circuit and/or positioned in the load space. In addition, some embodiments of the present invention include a battery and an on-board charger for recharging the battery using an external power supply.
[0004] In addition, some embodiments of the invention provide a method for controlling operation of a temperature control system having a plurality of refrigeration circuits, a battery pack, and a power cord. The method can include the acts of sensing a temperature in a load space, operating the temperature control system in a heating mode or cooling mode based, at least in part, on the sensed temperature, powering the temperature control system with power from the battery, and recharging the battery with an external power source.
[0005] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a front perspective view of a carrier and a temperature control system according to some embodiments of the present invention.
[0007] FIG. 2 is a front perspective view of the temperature control system shown in FIG. 1 .
[0008] FIG. 3 is a top view of the temperature control system shown in FIG. 1 .
[0009] FIG. 4 is a bottom view of the temperature control system shown in FIG. 1 .
[0010] FIG. 5 is a front view of the temperature control system shown in FIG. 1 .
[0011] FIG. 6 is a rear view of the temperature control system shown in FIG. 1 .
[0012] FIG. 7 is a left side view of the temperature control system shown in FIG. 1 .
[0013] FIG. 8 is a right side view of the temperature control system shown in FIG. 1 .
[0014] FIG. 9 is an enlarged front perspective view of the temperature control system shown in FIG. 1 with a portion cut away.
[0015] FIG. 10 is a schematic illustration of the temperature control system shown in FIG. 1 .
[0016] FIG. 11 is rear perspective of the battery pack shown in FIG. 1 .
[0017] FIGS. 12A-12B are flowcharts illustrating a method operating a temperature control system according to the present invention.
[0018] Before the various embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “central,” “upper,” “lower,” “front,” “rear,” and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. The elements of the temperature control system referred to in the present invention can be installed and operated in any orientation desired. In addition, terms such as “first,” “second,” and “third” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.
[0019] Also, the use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
DETAILED DESCRIPTION
[0020] FIG. 1 illustrates a carrier 10 and a temperature control system 14 according to some embodiments of the present invention. The carrier 10 of the illustrated embodiment is a shipping container and can be mounted on a straight truck, a tractor-trailer combination, a railcar, a ship, a boat, and/or an airplane. As shown in FIG. 1 , the carrier 10 includes an outer wall 18 , which at least partially defines a load space 22 and which at least partially supports the temperature control system 14 . The outer wall 18 includes a cargo door 24 , which provides access to the load space 22 for loading cargo into and unloading cargo from the load space 22 .
[0021] As used herein, the term “load space” includes any space to be temperature and/or humidity controlled, including transport and stationary applications for the preservation of food, beverages, plants, flowers, and other perishables and maintenance of a desired atmosphere for the shipment of industrial products.
[0022] In some embodiments, the temperature control system 14 can include a housing 25 , a battery pack 26 , and a storage chamber 30 . In the illustrated embodiment of FIG. 1 , the temperature control system housing 25 , the battery pack 26 , and the storage chamber 30 are located adjacent to the load space 22 in respective upper, central, and lower portions of the carrier 10 . In other embodiments, the temperature control system housing 25 , the battery pack 26 , and the storage chamber 30 can have alternative relative orientations (e.g., horizontally or vertically in-line, or spaced throughout the carrier 10 ) and locations within the carrier 10 (e.g., the temperature control system housing 25 can be located in a lower portion of the carrier 10 , the battery pack 26 can be located in a central portion of the carrier 10 , and the storage chamber 30 can be located in a lower portion of the carrier 10 ).
[0023] The temperature control system 14 of the illustrated embodiment of FIG. 1 is operable to condition load space air and to maintain load space air temperature and/or humidity within a desired range surrounding a set point temperature T SP (e.g., 5° C.) and/or a set point humidity H SP (e.g., 60°).
[0024] In some embodiments, the temperature control system housing 25 supports an evaporator 34 and defines an air inlet 38 and an air outlet 42 . In other embodiments, the temperature control system housing 25 can include two, three, or more air inlets 38 and/or two, three, or more air outlets 42 . During operation of the temperature control system 14 and as explained in greater detail below, one or more fans or blowers 44 draw air from the load space 22 into the evaporator 34 through the air inlet 38 , direct the load space air across evaporator coils (described below), and vent the air back into the load space 22 through the air outlet 42 . In some embodiments, load space air is also or alternately vented to the outside of the carrier 10 to vent CO 2 or other exhaust gasses from the load space 22 and to maintain the quality of the air in the load space 22 .
[0025] In the illustrated embodiment of FIGS. 1 and 9 , the temperature control system housing 25 supports a first refrigeration circuit 46 , a second refrigeration circuit 50 , and a third refrigeration circuit 54 . In other embodiments, the temperature control housing 25 can at least partially support one, two, four, or more refrigeration circuits.
[0026] In some embodiments, such as the illustrated embodiment of FIGS. 2-10 , the first refrigeration circuit 46 includes and fluidly connects a compressor 58 (e.g., a hermetic compressor), an evaporator coil 62 , and a condenser 66 located in respective upper, lower, and central portions of the temperature control system housing 25 . More particularly, in the illustrated embodiment of FIGS. 1-10 of the present invention, the compressor 58 is positioned on one side of the temperature control system housing 25 , the condenser 66 is positioned on the other side of the temperature control system housing 25 , and the evaporator coil 62 extends through the evaporator 34 . In other embodiments, one or more of the compressor 58 , evaporator coil 62 , and condenser 66 can have alternative relative orientations (e.g., horizontally or vertically in-line or spaced throughout the housing) and locations within the housing 25 (e.g., the condenser 66 can be located in an upper portion of the housing 25 , the compressor 58 can be located in a central portion of the housing 25 , and the evaporator coil 62 can be located in a lower portion of the housing 25 ).
[0027] In embodiments having a second refrigeration circuit 50 , such as the illustrated embodiment of FIGS. 2-10 , the second refrigeration circuit 50 can include and fluidly connect a compressor 74 (e.g., a hermetic compressor), an evaporator coil 78 , and a condenser 82 located in respective upper, lower, and central portions of the temperature control system housing 25 . More particularly, in the illustrated embodiment of FIGS. 1-10 of the present invention, the compressor 74 is positioned on one side of the temperature control system housing 25 adjacent to the compressor 58 of the first refrigeration circuit 46 , the condenser 82 is positioned on the other side of the temperature control system housing 25 adjacent to the condenser 66 of the first refrigeration circuit 46 , and the evaporator coil 62 extends through the evaporator 34 adjacent to the evaporator coil 62 of the first refrigeration circuit 46 . In other embodiments, one or more of the compressor 74 , evaporator coil 78 , and condenser 82 can have alternative relative orientations and locations within the housing 25 .
[0028] In embodiments having a third refrigeration circuit 54 , such as the illustrated embodiment of FIGS. 2-10 , the third refrigeration circuit 54 can include and fluidly connect a compressor 90 (e.g., a hermetic compressor), an evaporator coil 94 , and a condenser 98 located in respective upper, lower, and central portions of the temperature control system housing 25 . More particularly, in the illustrated embodiment of FIGS. 2-10 of the present invention, the compressor 90 is positioned on one side of the temperature control system housing 25 adjacent to the compressor 58 of the first refrigeration circuit 46 and the compressor 74 of the second refrigeration circuit 50 , the condenser 98 is positioned on the other side of the temperature control system housing 25 adjacent to the condenser 66 of the first refrigeration circuit 46 and the condenser 82 of the second refrigeration circuit 50 , and the evaporator coil 94 extends through the evaporator 34 adjacent to the evaporator coil 62 of the first refrigeration circuit 46 and the evaporator coil 78 of the second refrigeration circuit 50 . In other embodiments, one or more of the compressor 90 , evaporator coil 94 , and condenser 98 can have alternative relative orientations and locations within the housing 25 .
[0029] In the illustrated embodiment of FIGS. 2-10 , the compressors 58 , 74 , and 90 of the first second and third refrigeration circuits 46 , 50 , 54 are grouped together to define a compressor cell 106 . The condensers 66 , 82 , 98 of the first, second and third refrigeration circuits 46 , 50 , 54 are grouped together to define a condenser cell 110 . The evaporators 62 , 78 , and 94 of the first, second and third refrigeration circuits 46 , 50 , 54 are grouped together and are positioned together to define an evaporator cell 114 . In the illustrated embodiment of FIGS. 2-10 , the evaporator cell 114 is positioned in the evaporator housing 25 .
[0030] In some embodiments of the present invention, the temperature control system 14 includes a controller 118 having a microprocessor 122 which controls and coordinates operation of the temperature control system 14 . In these embodiments, the controller 118 is programmed to operate the temperature control system 14 in a COOLING mode, a HEATING mode, a DEFROST mode, and a NULL mode, based at least in part upon the set point temperature T SP , the set point humidity H SP , the ambient temperature, the load space temperature, and/or the cargo in the load space 22 .
[0031] The temperature control system 14 can include one or more temperature sensors 138 . In some embodiments, a temperature sensor 138 is positioned in the load space 22 to record load space temperature. In other embodiments, a temperature sensor 138 is positioned in the air inlet 38 . In still other embodiments, a temperature sensor 138 is positioned in the air outlet 42 . The temperature control system 14 can also or alternately include temperature and/or pressure sensors distributed along one or more of the first, second, and third refrigeration circuits 46 , 50 , 54 for sensing the temperature and/or pressure of refrigerant in one or more of the first, second, and third refrigeration circuits 46 , 50 , 54 . In these embodiments, data recorded by the sensors 138 is transmitted to the controller 118 .
[0032] As shown in FIGS. 2-10 , the temperature control system 14 can include one or more heating elements (e.g., heating coils, pan heaters, propane-fueled burners, and the like) positioned in the evaporator 34 for heating load space air and/or defrosting the evaporator coils 62 , 78 94 . In other embodiments, warm refrigerant can be directed through the evaporator coils 62 , 78 , 94 to warm load space air, or alternatively, to defrost the evaporator coils 62 , 78 , 94 during operation in the DEFROST mode. In the illustrated embodiment of FIGS. 2-10 , first and second heating elements 130 , 134 are positioned in the evaporator 34 adjacent to the evaporator coils 62 . 78 . 94 .
[0033] As mentioned above, the temperature control system 14 can include a battery pack 26 . In the illustrated embodiment of FIGS. 1 and 11 , the battery pack 26 includes a battery housing 139 supported in an opening in the outer wall 18 adjacent to the temperature control system housing 25 .
[0034] The battery pack 26 of the illustrated embodiment includes first and second battery cells 140 a , 140 b . In other embodiments, the battery pack 26 can include one, two, four, or more battery cells 140 . Each of the battery cells 140 is operable to store an electrical charge and to power the temperature control system 14 .
[0035] During normal operation of the temperature control system 14 , the battery cells 140 a , 140 b supply power to elements of the temperature control system 14 . In this manner, the temperature control system 14 can operate independently for extended periods of time (e.g., between about twenty and about forty hours) without requiring an external power supply. More particularly, the temperature control system 14 and the carrier 10 of the present invention can be loaded onto airplanes and other vehicles and can be moved away from external power supplies for extended periods of time.
[0036] The battery pack 26 also supports a transformer 141 and first and second battery chargers 142 a , 142 b for charging corresponding battery cells 140 a , 140 b . When the electrical charge in one or more of the battery cells 140 a , 140 b is low and/or when the temperature control system 14 and the carrier 10 are located near an external power supply (e.g., in a warehouse or on a loading dock), electrical power can be transferred from the external power supply to the battery chargers 142 a , 142 b to charge the battery cells 140 a , 140 b and to power elements of the temperature control system 14 . In some embodiments, electrical power is directed through the transformer 141 , which transforms the electrical power from the external power source into a form which can be stored by the batteries (e.g., the transformer converts the electrical power from AC to DC). In other embodiments, the transformer 141 and/or the battery chargers 142 a , 142 b convert power from a first voltage to a second voltage (e.g., from 24 volts to 12 volts).
[0037] In some embodiments, such as the illustrated embodiment of FIG. 1 , a power cord 143 is stored in the storage chamber 30 . In these embodiments, an operator can use the power cord 143 to electrically connect one or more of the battery chargers 142 a , 142 b and the transformer 141 to the external power source. In addition, in some embodiments, a number of plugs or adapters 144 are housed in the storage chamber 30 . Each of the adapters 144 has a different configuration and is engageable with a different external power source.
[0038] FIGS. 12A and 12B illustrate a method of operating a temperature control system 14 according to the present invention. More particularly, FIGS. 12A and 12B outline an algorithm in the form of a computer program that can be used to practice the present invention.
[0039] Each time the temperature control system 14 is switched on (i.e., booted-up), the controller 1 8 initiates a startup routine. Among other things, the startup routine determines if the temperature control system 14 is operating correctly and searches for errors in the controller's programming and mechanical failures in the temperature control system 14 . If an error is detected, the controller 118 can be programmed to activate an alarm to alert an operator. 100391 Following startup, the temperature sensor(s) 138 record a temperature T and transmit temperature data to the controller 118 at act 146 . As explained above, temperature sensors 138 can be positioned throughout the load space 22 and the temperature control system 14 . Accordingly, in some embodiments of the present invention, the temperature T recorded by the sensors 138 can be the temperature of air in the load space 22 , the temperature of air entering the evaporator 34 , the temperature of air in the air inlet 38 , the temperature of air exiting the evaporator 34 , the temperature of air in the air outlet 42 , and/or the temperature of refrigerant exiting the evaporator coils 62 , 78 , 94 of first, second, and third refrigeration circuits 46 , 50 , 54 .
[0040] At act 150 , the controller 118 compares the temperature T recorded by the sensor(s) 138 to the set point temperature T SP . If the temperature T is greater than the set point temperature T SP (“NO” at act 150 ), the controller 118 is programmed to operate the temperature control system 14 in a COOLING mode (described below). Alternatively, if the temperature T is less than or equal to the set point temperature T SP (“YES” at act 150 ), the controller 118 is programmed to move to act 154 .
[0041] At act 154 , the controller 118 can be programmed to determine whether the temperature T is greater than or equal to the total of the set point temperature T SP minus a temperature constant T 0 (e.g., between about 0.2° C. and about 0.3° C.). If the temperature T is greater than or equal to the total of the set point temperature T SP minus the temperature constant T 0 “YES” at act 154 ), the controller 118 is programmed to return to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 154 and act 146 . If the temperature T is less than the total of the set point temperature T SP minus the temperature constant T 0 (“NO” at act 154 ), the controller 118 is programmed to move to act 156 .
[0042] At act 156 , the controller 118 is programmed to determine whether the temperature T is less than or equal to the total of the set point temperature T SP minus a temperature constant T 1 (e.g. between about 0.5° C. and about 0.6° C.). If the temperature T is less than or equal to the total of the set point temperature T SP minus the temperature T 1 (“YES” at act 156 ), the controller 118 is programmed to move to act 158 and to activate the first and second heaters 130 , 134 and the tan 44 to heat the load space air. The controller 118 then returns to act 146 . In some embodiments the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 158 and act 146 . If the temperature T is greater than the total of the set point temperature T SP minus the temperature constant T 1 (“NO” at act 156 ), the controller 118 is programmed to move to act 162 .
[0043] At act 162 , the controller 118 is programmed to determine whether the temperature T is less than or equal to the total of the set point temperature T SP minus a temperature constant T 2 (e.g., between about 0.4° C. and about 0.5° C.). If the temperature T is less than the total of the set point temperature T SP minus the temperature constant T 2 (“YES” at act 162 ), the controller 118 is programmed to move to act 166 and to activate the first heater 130 and the fan 44 to heat the load space air. The controller 118 then returns to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 166 and act 146 . If the temperature T is greater than the total of the set point temperature T SP minus the temperature constant T 2 (“NO” at act 162 ), the controller 118 is programmed to move to act 170 .
[0044] At act 170 , the controller 118 is programmed to deactivate the first and second heaters 130 , 134 and the fan 44 and to operate the temperature control system 14 in a NULL mode. In some embodiments the controller 118 is programmed to operate the temperature control system 14 in the NULL mode for a predetermined time and then to return to act 146 . In other embodiments, the controller 118 is programmed to include a delay (e.g., 2 minutes) between act 170 and act 146 .
[0045] As mentioned above, the controller 118 is programmed to operate the temperature control system 14 in a COOLING mode if the temperature T is greater than the set point temperature T SP (“NO” at act 150 ). As shown in FIG. 12B , the controller 118 is programmed to determine whether the temperature T is greater than or equal to the sum of the set point temperature T SP and a temperature constant T 3 (e.g., between about 1.5° C. and about 1.2° C.). If the temperature T is greater than the sum of the set point temperature T SP and the temperature constant T 1 (“YES” at act 172 ), the controller 118 is programmed to move to act 174 and to operate compressors 58 , 74 , 90 of the first, second, and third refrigeration circuits 46 , 50 , 54 at HIGH speed and operate the fan 44 to direct load space air across the evaporator coils 62 , 78 , 94 of the first second, and third refrigeration circuits 46 , 50 , 54 to cool the load space air. The controller 118 then returns to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 174 and act 146 . If the temperature T is less than the sum of the set point temperature T SP and the temperature constant T 3 (“NO” at act 172 ) the controller 118 is programmed to move to act 178 .
[0046] At act 178 , the controller 118 is programmed to determine whether the temperature T is greater than or equal to the sum of the set point temperature T SP and a temperature constant T 4 (e.g. between about 1.1° C. and about 1.2° C.). If the temperature T is greater than or equal to the sum of the set point temperature T SP and the temperature constant T 4 (“YES” at act 178 ), the controller 118 is programmed to move to act 182 and to operate the compressors 58 , 74 , 90 of the first, second, and third refrigeration circuits 46 , 50 , 54 at LOW speed and to operate the fan 44 to direct load space air across the evaporator coils 62 , 78 , 94 of the first, second, and third refrigeration circuits 46 , 50 , 54 to cool the load space air. The controller 118 then returns to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 182 and act 146 . If the temperature T is less than the sum of the set point temperature T SP and the temperature constant T 4 (“NO” at act 178 ), the controller 118 is programmed to move to act 186 .
[0047] At act 186 , the controller 118 is programmed to determine whether the temperature T is greater than or equal to the sum of the set point temperature T SP and a temperature constant T 5 (e.g., between about 0.7° C. and 0.8° C.). If the temperature T is greater than or equal to the sum of the set point temperature T SP and the temperature constant T 5 (“YES” at act 186 ), the controller 18 is programmed to move to act 190 and to operate the compressors 58 , 74 of the first and second refrigeration circuits 46 , 50 at LOW speed and operate the fan 44 to direct load space air across the first and second evaporator coils 62 , 78 to cool the load space air. The controller 118 then returns to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 190 and act 146 . If the temperature T is less than the sum of the set point temperature T SP and the temperature constant T 5 (“NO” at act 186 ), the controller 118 is programmed to move to act 194 .
[0048] At act 194 , the controller 118 is programmed to determine whether the temperature T is greater than or equal to the sum of the set point temperature T SP and a temperature constant T 6 (e.g., between about 0.3° C. and about 0.4° C.). If the temperature T is greater than or equal to the sum of the set point temperature T SP and the temperature constant T 6 (“YES” at act 194 ), the controller 118 is programmed to move to act 198 and to operate the compressor 58 of the first refrigeration circuit 46 at LOW speed and operate the fan 44 to direct load space air across the evaporator coil 62 of the first refrigeration circuit 46 to cool the load space air. The controller 118 then returns to act 146 . In some embodiments, the controller 118 can be programmed to include a delay (e.g., 2 minutes) between act 198 and act 146 . If the temperature T is less than the sum of the set point temperature T SP and the temperature constant T 6 (“NO” at act 194 ), the controller 18 is programmed to move to act 202 .
[0049] At act 202 , the controller 118 is programmed to deactivate the compressors 58 , 74 , 90 of the first, second, and third refrigeration circuits 46 , 50 , 54 and the fan 44 and to operate the temperature control system 14 in the NULL mode. In some embodiments the controller 118 is programmed to operate the temperature control system 14 in the NULL mode for a predetermined time and then to return to act 146 . In other embodiments, the controller 118 is programmed to include a delay (e.g., 2 minutes) between act 202 and act 146 .
[0050] The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.
[0051] For example, while reference is made herein to a temperature control system 14 having temperature sensors 138 and to a method of operating a temperature controls system based at least in part, upon temperature data, in alternate embodiments of the present invention, the temperature control system 14 can include one or more pressure sensors and the temperature control system 14 can be controlled and/or operated using pressure data recorded by the pressure sensors. | An air cargo container temperature control system and method utilizing multiple refrigeration circuits and a controller that activates one or more of the refrigeration circuits in various modes to maintain temperature control. Each of the refrigeration circuits comprises a compressor, a condenser, and an evaporator all in fluid communication to form each refrigeration circuit. Additionally, heating elements are positioned in an evaporator cell for heating load space air and/or defrosting evaporator coils. The system is also provided with a battery pack having a transformer and battery chargers for charging corresponding battery cells by transforming power from an external source. The method compares a measured temperature to a set point temperature and activates one or more refrigeration circuits depending on the temperature difference. | 5 |
FIELD OF THE INVENTION
[0001] The field of this invention is closures for bottles and more particularly for bottles capped with a rotary capper.
BACKGROUND OF THE INVENTION
[0002] High speed filling lines are commonly used to fill a variety of containers of various shapes and sizes. The machinery typically positions the receiving container for the product in alignment with a fill nozzle or outlet. After the product is delivered, a closure is put on to seal the bottle. The capping machinery has controls built in that are used in placement of the closure. In order to assure rapid and secure placement of the closure, the equipment needs to be able to deliver certain forces and torques to secure the closure. For closures that secure by snap or interference fit, there is a balance that needs to be drawn between getting a secure slip free contact between the container and the closure and the limits of the machinery to deliver the desired force and keep the filling line moving at the desired speed. If the clearances are too tight the resulting required forces can get too high for the capping equipment. This can result in an incomplete placement of the closure on the container and potential product leakage along the distribution chain.
[0003] FIGS. 1-6 illustrate this problem in a prior art bottle that uses a snap fit closure onto the neck of an elongated bottle. Referring to FIG. 1 , the bottle 10 has a neck generally indicated at 12 at its top end. A support ring 14 defines the beginning of the neck 12 and features an upwardly oriented shoulder 16 . A ring 18 located above support ring 14 defines an undercut radial surface 20 . Above ring 18 and working up to the top of the neck 12 are a pair of transition surfaces 22 and 24 that ultimately lead to the top 26 of the neck 12 . The closure 28 is shown above the bottle 10 in the position that the capping machinery would hold it before driving it home onto the neck 12 . Closure 28 has an outer surface 30 and an inner surface 32 . Inner surface 32 has a series of circumferentially spaced inwardly oriented projections 34 that each features a radial surface 36 adjacent a tapered and downwardly extending surface 38 . Inner surface 32 also features a longitudinally extending and generally rectangular shaped key 40 having a taper 42 at its lower end. A ring 44 is disposed concentrically to inner surface 32 and has a gradual exterior outward taper 46 . Neck 12 further comprises a longitudinally oriented gap 48 which is wider than key 40 , for reasons that will be explained below. Closure 28 has an outlet 50 which can be any known design for getting the product out of the bottle 10 when it is placed in use.
[0004] With the components now having been described, the process of assembling the closure 28 to the bottle 10 will now be described and in the process, its limitations will be more readily understood. Those skilled in the art will appreciate that the machinery that is not shown receives a closure 28 in a random orientation with regard to the location of key 40 . Stated differently, key 40 may or may not be axially aligned with gap 48 when the closure 28 is brought down on the neck 12 . Comparing FIGS. 1 and 2 , it can be seen that the closure 28 has been brought closer to the neck 12 and that closure 28 has been rotated about its vertical axis to change the orientation of the key 40 with respect to the gap 48 . In FIG. 2 , they are in further misalignment than they were in FIG. 1 . FIG. 3 compared to FIG. 2 shows further downward movement of closure 28 as well as a further rotation of about 90° about its vertical axis as compared to the FIG. 2 position. In FIG. 3 , tapered surface 38 has landed on transition surface 22 of neck 12 . Taper 42 at the lower end of key 40 has landed on tapered surface 25 just below the top 26 of the neck 12 . It is apparent that key 40 is still misaligned with gap 48 in this position. Tapered surface 46 of ring 44 is inside the top end 26 and on the verge of contact with the inside wall of the neck 12 . Now comparing FIG. 4 to FIG. 3 , the closure 28 has been pushed further down but not rotated by much. At this point radial surface 36 has been snapped to below radial surface 20 . Tapered surface 46 of ring 44 is now in contact with the inside surface of the neck 12 just below end 26 . Key 40 is now straddling ring 18 . Those skilled in the art will appreciate that subsequent effort to rotate the closure 28 after being forced down to the FIG. 4 position will engender significant resistance from several contact points with neck 12 . The key 40 extending over ring 18 will resist rotation as will the rubbing of ring 44 inside the upper end 26 of the neck 12 . Finally, there is an upward force that forces radial surface 36 of closure 28 up against radial surface 20 of ring 18 on the neck 12 . This residual force results from the dimensions of the components and the driving of the closure 28 down over ring 18 . The problem in the past with this design is that the equipment is either torque limited or has settings that limit applied torque to the closure 28 to avoid component damage by forcing a fit in situations where the components may not be totally in axial alignment. The compound effect of these interference fits that are desirable in assuring the securing of the closure 28 to the bottle 10 become a disadvantage during the filling process. Comparing now FIG. 5 to FIG. 4 , it can be seen that the closure is rotated about its longitudinal axis to bring key 40 closer to gap 48 . The assembly is finished when key 40 snaps off ring 18 and settles into gap 48 to rotationally lock the closure 28 to the neck 12 .
[0005] The present invention improves the configuration of the components to greatly reduce the required torque to assemble them while, in the end, allowing them to be securely connected to each other as in the past. One way this is accomplished is an emphasis on getting the components into their final alignment positions at a time when less interference contact exists, thus greatly reducing the required torque for rotating the closure into its final position. In the end the closure is just as secure as in the prior art design but the assembly process has been optimized in view of the low applied torque required to reach the final made up position of the components. These and other advantages of the present invention will more readily be understood by those skilled in the art from a review of the remaining drawings and the associated description of the preferred embodiment as well as the claims for the invention that appear below.
SUMMARY OF THE INVENTION
[0006] A closure system for a container reduces the needed torque for assembly by minimizing frictional resistance to rotation of the closure into its desired alignment with the container before the closure is driven home onto the container neck. The reduction in the torque resistance during the application of the closure allows the high speed filling machinery to work within its torque limits and minimizes damage to the parts during the filling and sealing operation in a high speed filling line.
DETAILED DESCRIPTION OF THE DRAWINGS
[0007] FIGS. 1-6 are a series of views showing the assembly in progress of applying the closure to the neck of a container in the prior art design; and
[0008] FIGS. 7-12 are sequential views of the present invention showing the closure being applied to the container.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] Referring to FIG. 7 , the container 50 accepts the closure 52 . Container 50 has a neck 54 having an optional ring 56 that features an upper surface 58 that, if used, does not necessarily support the closure 52 . Lower end 60 of closure 52 ultimately comes to be supported off of surface 58 , as shown in FIG. 12 or can lay close to it without contact. Neck 54 further comprises a circumferential recess 62 disposed between rings 64 and 66 . Ring 66 has a ramp 68 adjacent an indexing gap 70 that spans rings 64 and 66 and recess 62 . Closure 52 had an interior circumferential surface 72 featuring a circular projection 74 that may be continuous or in discrete segments. Inner ring 76 has an exterior tapered surface 78 . A longitudinally oriented indexing key 80 has a tapered lower end 82 that extends down to a point short of projection 74 . Closure 52 has an outlet 84 of a type known in the art. Those skilled in the art will appreciate that indexing key 80 can be on the neck 54 and indexing groove 70 can be on the closure 52 as that option is a transposition of parts that function in the same way. In the same manner the rings 64 and 66 and the recess 62 between them can be transposed with projection or bead 74 within the scope of the invention.
[0010] FIG. 8 shows the closure. 52 brought closer to the container 50 while it is rotated about a vertical axis. There is still no contact at this time. In FIG. 9 the closure has been lowered and rotated a further amount. Note that the key 80 is still out of alignment with the gap 70 . However, at this time the circular projection 74 has passed ring 66 and landed in recess 62 between rings 64 and 66 for temporary support in that position. The lower end 82 of the key 80 is just above or right at ring 66 . Tapered surface 78 of ring 76 is inside the upper end 86 of the neck 54 and preferably out of contact or in light guiding contact with the inside surface 88 of the neck 54 . Lower end 60 of closure 52 is above surface 58 .Having reached this position, further relative rotation can occur with minimal resistance as compared to the prior design described in FIGS. 1-6 . For one thing the key 80 is not straddling any ring such as 64 or 66 even when it is misaligned with the gap 70 . Projection or bead 74 having jumped over ring 66 on the way down into recess 64 now loosely fits in that recess 64 and uses rings 64 and 66 for guides, as the closure 52 is further rotated, as shown in FIGS. 10 and 11 . Finally, the closure is guided for rotation by the extension of ring 76 into upper end 86 but without significant or any dragging of tapered surface 78 on the inside surface 88 of neck 54 . In essence the closure is guided at three locations off of neck 54 as the closure 52 is rotated to bring the key 80 into alignment with gap 70 . These three points of support for low resistance to applied torque are the disposing of projection 74 loosely within recess 64 ; letting lower end 82 of key 80 ride on or slightly above ring 66 and guiding the top of closure 52 within neck 54 by the extension of ring 76 into end 86 when tapered surface 78 is just out of touch or lightly contacting inside surface 88 of neck 54 .
[0011] As shown in FIG. 11 , the 80 has been turned into alignment with gap 70 to allow the closure 52 to now be pushed down as shown in FIG. 12 .By doing that, the lower end 60 comes to rest on or near support surface 58 .Projection 74 has jumped out of recess 62 to a position under ring 64 and taper 78 of ring 76 is in an interference contact with inside surface 88 of neck 54 . It should be noted that the movement in FIG. 12 involves no rotation as alignment of the key 80 with the gap 70 has previously been achieved. In this position ring 64 retains projection 74 to hold the closure 52 to the neck 54 .
[0012] Those skilled in the art will appreciate that a number of initial orientations of the key 80 to the gap 70 are possible when the FIG. 9 position is initially reached. The purpose of the ramp 68 is to push closure 52 in a clockwise direction to begin the orientation process until key 80 winds up in alignment with gap 70 . Of course if there is perfect initial alignment between key 80 and gap 70 the closure is simply pushed down as the machinery senses resistance to rotation because key 80 will not jump out of gap 70 and over ramp 68 without an amount of torque that will trip a switch on the machinery against over-torque. At that point, the equipment will simply push the closure 52 straight down. To reduce resistance to rotation even further, the neck 54 and the closure 52 internals can be made from a lubricious material or can have a small amount of a lubricant applied to the contacting surfaces to further reduce resistance to turning to seek the proper orientation before pushing the closure 52 to its final position on the neck 54 .
[0013] The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made without departing from the invention. | A closure system for a container reduces the needed torque for assembly by minimizing frictional resistance to rotation of the closure into its desired alignment with the container before the closure is driven home onto the container neck. The reduction in the torque resistance during the application of the closure allows the rotary filling machinery to work within its torque limits and minimizes damage to the parts during the filling and sealing operation in a bottle filling line. | 1 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
This invention relates generally to depth mapping systems and particularly to a system wherein a plurality of depths of a submerged surface are simultaneously displayed.
In mapping the depth of an ocean bottom or of an object of interest submerged within a water body. It is particularly desirable that any depths developed as a result of such a mapping system be simultaneously presented as a family of depths which, taken as a whole, present an integrated picture of a preselected area of the water bottom. One example of such a system used to determine depth in an ocean body utilizes a pulsed laser system and a single aperture receiver which sequentially pulses and then processes the signal information to provide a discrete piece of depth information. Succeeding items of information are then sequentially provided by further laser pulses and corresponding processing. Such systems are often susceptible to pulse variations within the laser system which can introduce significant errors into the resultant information.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a depth mapping system which simultaneously exhibits a plurality of depths representative of a predetermined submerged surface area. Another object of the invention is to provide a mapping system having a pulsed laser which provides a single pulse directed into a water body to cause the simultaneous generation of a plurality of interrelated depths. A further object of the present invention is to provide a multi-apertured photomultiplier tube having the apertures thereof prearranged in a grid for simultaneously producing a plurality of interrelated depths.
Briefly, these and other objects are accomplished by a depth mapping system having a pulsed laser which directs a single pulse at a predetermined water area and a multi-aperture photomultiplier tube which receives backscattered radiation signals generated as a result of the single laser pulse from both the air-water interface and submerged surface. A signal comparator simultaneously compares each of the submerged surface radiation signals, as received in a grid determined by the operational characteristics of the photomultiplier tube, against the air-water interface radiation signal and drives a CRT display which ilustrates the depths of the submerged surface over the predetermined area. The respective depths illustrate relationships between one another in a display calibrated in three dimensions and in transformation registration with the apertures of the photomultiplier tube.
For a better understanding of these and other aspects of the invention, reference may be made to the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an area of ocean which can be scanned by the system of the present invention;
FIG. 2 is a block diagram of the system according to the present invention;
FIG. 3 is a block diagram of the signal comparator noted in FIG. 2 of the invention;
FIG. 4 illustrates the front screen of the photomultiplier tube shown in FIG. 2 of the invention; and
FIG. 5 illustrates the display of a plurality of depths as generated by the system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown an airplane 10 having a depth mapping system attached underneath the fuselage thereof. A pulse P is directed from the system 12 downwardly into an area of an ocean body defined by the air-water interface surface S A and a plurality of water bottom contoured surfaces S B . In the course of traveling from the airplane 10 downwardly towards the water, the pulse P spreads outwardly and illuminates a first area I A at the surface S A , and a second area I B on the water bottom surface S B . As will be explained with greater detail hereinafter, a plurality of backscattered radiation pulses are received from both the area I A which is exemplified by the return pulse A, and the area I B which is exemplified by the return pulse B.
Referring now to FIG. 2, there is shown a block diagram of the processor system 12 as used within the present invention. A pulsed laser 14 directs an output pulse P towards a prism 16 which reflects the pulse P towards a scanning mirror 18 which is selectively rotated by a mechanical interconnection to a conventional scan drive 20. The pulse P is reflected by mirror 18 outwardly from the system 12 and towards the ocean body as noted in FIG. 1. The mirror 18 also serves to receive the backscattered radiation pulses A and B as noted in FIG. 1 and reflects these pulses along with other backscattered radiation pulses (not shown) towards a filter 22 which passes the incoming radiation pulses to a focusing lens 24. The lens 24 focuses the radiation pulses towards a multi-apertured photomultiplier tube 26 having a screen 28 adapted to receive the incoming radiation. The tube 26 provides a first output to a first input of a signal comparator 32 and a second output to a level detector 34 whose output is connected to a second input of the comparator 32. The comparator 32 provides an output to a display interface 36 whose output is connected to a display 38.
Referring now to FIG. 3, there is shown a block diagram of the signal comparator 32 noted in FIG. 2. The second output of the photomultiplier tube 26 is connected to the set input of a flip-flop 40. The corresponding "1" output of the flip-flop 40 is connected to one input of an AND gate 42 whose second input is connected to receive an output from a clock 44. The output of the AND gate 42 is commonly connected to the clock inputs of a plurality of forty eight counters 46. Each of the counters 46 has an inhibit input line connected, respectively, to each of the forty eight outputs from the photomultiplier tube 26. Outputs from each of the counters 46 are connected, respectively, to inputs of digital to analog converters 52 which provide, respectively, a plurality of forty eight outputs for connection to the display interface 36.
Referring now to FIG. 4 there is shown a front view of the screen 28 of the photomultiplier tube 26. The screen 28 is provided with a plurality of forty eight apertures 30 arranged in an 8×6 grid such that the Y excursion of the grid is divided into six scanning units and the X excursion of the grid is divided into eight scanning units.
Referring now to FIG. 5 there is illustrated a typical depth mapping display as will be generated by the present invention and illustrated on display 38 noted in FIG. 2. The display is calibrated in a series of six display units in the Y direction and a series of eight display units in the X direction. This display is designed to be a one-on-one grid transformation from the scanning units and apertures of the photomultiplier tube onto a rectangular grid which is now calibrated in units of feet. Moreover, each of the scanning lines formed across the X display units is further calibrated as to depth with the lowermost boundary of the Y display units forming the zero depth. The height of any individual line within a respective grid unit defined by the X and Y display units will therefore determine the depth of the water bottom surface or other submerged surface within that particular area as scanned by the photomultiplier tube 26.
Referring again to FIGS. 1-5, the operation of the invention will now be explained. The airplane 10, while flying over a water body, causes the projected laser pulse, which is typically in the blue green spectrum, to be directed downwardly into the water body and to spread about respective illuminated areas I A and I B . The pulse, as generated by the laser 14, may be directed into a preselected area of the water body or succeeding preselected areas thereof by motion of the scanning mirror 18 as controlled by the scan drive 20. Backscattered radiation such as exemplified by the pulse A received from the air-water interface and the pulse B received from the bottom contours of the water body are collected by the scanning mirror 18 and directed through the filter 22. The filter 22 is tuned to pass only the backscattered wavelengths of interest, such as blue-green wavelengths if used in conjunction with an ocean body, and to reject all other radiated signals. The filtered rays are then passed from the filter 22 through the focusing lens 24 onto the screen 28 of the photomultiplier tube 26. It is intended that the scanning mirror 18 will be driven by the scan drive 20 in such a manner that the optimum amount of backscattered radiation is properly focused onto the matrixed apertures 30 of the tube 26. Although shown in the preferred embodiment as a mechanical scanning arrangement, the photomultiplier tube apertures 30 may also be scanned with electronic means well known to those skilled in the art. Once having focused the backscattered radiation onto the apertures of the tube, each of the apertures processes the incoming radiation to provide an output signal on one of the forty eight output signal lines coming from the photomultiplier tube 26. The second output from the tube 26 is connected to any one of the forty eight output lines from the apertures 30 and is connected to the input of the level detector 34. In operation, the first backscatter signal to be received from the water body as a result of directing a laser pulse therein will be the signal reflected from the air-water interface. Assuming a substantially level water surface S A , each of the forty eight apertures of the photomultiplier tube will receive the backscattered interface signal at substantially the same time, hence any one of the outputs generated from the apertures is suitable to drive the level detector 34. Experience has shown that the backscattered signal received from the air-water interface will be substantially larger in magnitude than any succeeding signals from the water bottom or a submerged object. Consequently, the level detector 34 is set to provide an output signal to the comparator 32 only when the greater magnitude of the backscattered interface signal is received and thus discriminates between the air-water interface backscattered signal and other radiated signals having lesser magnitudes. The signal comparator 32 receives the output signal from the level detector 34 which sets flip-flop 40 to activate AND gate 42 for the passage of clock signals generated by the clock 44. Each of the counters 46, respectively identified as corresponding to discrete apertures within the screen 28 of the tube 26, begin counting upon receipt of the signals from the clock 44. As the various backscattered signals are sensed by the respective apertures of the photomultiplier 26 in time sequence according to the depth of the water body or submerged object, the forty eight input lines to the comparator 32 become activated to sequentially inhibit the counters 46. Accordingly, each of the counters 46 registers a count indicative of a time relationship between the reception of a first backscattered pulse from the air-water interface and the reception of a second backscattered pulse from a particular preselected area of the water bottom surface. The digital to analog converters 52 each receive, respectively, the output from the counters 46 and convert the counter outputs to an analog form for further processing by the display interface 36. The interface 36 arranges the incoming analog data into a grid format suitable for illustration on the display 38 and which is further illustrated in FIG. 5. Accordingly, when viewing the display of FIG. 5 it is noted that the grid area defined by display units X 1 Y 6 corresponds to the radiated information detected by the aperture 30 shown in FIG. 4 located according to scan units X 1 Y 6 . The height of the signal level shown in the grid area X 1 Y 6 of FIG. 5 is indicative of the signal level received from the respective analog converter 52 in the comparator 32 which corresponds to the depth of the water bottom or submerged object within that particular portion of the illuminated area. Provided with a sufficient number of apertures within the scanning area of a multi-apertured receiver tube, the many depths can be easily provided for greater resolution and a more realistic indication of the true contours of the water body or submerged object.
Thus it may be seen that there has been provided a novel laser mapping system for simultaneously presenting a plurality of depth of a preselected water bottom area or submerged object.
Obviously many modifications and variations of the invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. | A depth mapping system is carried from an aircraft flying above the water. pulsed laser directs a pulse at a predetermined water area and a multi-apertured photomultiplier tube receives backscattered or reflected radiation signals from both the air-water interface and a submerged surface. A signal comparator simultaneously compares each of the reflected radiation signals against the air-water interface radiation signal and drives a CRT display which illustrates the depth of the reflecting surface over the predetermined area. | 6 |
This application is a division of application Ser. No. 506,858, filed 6/22/83 now abandoned.
BACKGROUND OF THE INVENTION
Microvascular free flap technology provides a valuable means of transferring large flaps in one procedure, however, there are several major disadvantages. Microvascular free flaps are inappropriate for the reconstruction of small defects. The procedure is time-consuming and requires a skilled microvascular surgeon. Sufficiently large recipient vessels must be found. In addition, it is not uncommon to lose the flap from thrombosis of the anastomosed vessels.
It is known from past experience with tube pedicle flaps and cross leg flaps that the transferred flap is revascularized by the recipient bed in a relatively short time allowing for eventual transection of the pedicle, the distal part of the flap now supported totally by the recipient bed.
Artificial blood has heretofore been investigated for use in transfusion and organ preservation studies. Three types of artificial blood, i.e. free hemoglobin solutions, chelating agents, and perfluorocarbon emulsions have been investigated since the late 1960's in the preservation studies. Commercially available perfluorocarbon emulsion, Fluosol-DA 20 1/1 has been available for research purposes as it is capable of carrying large quantities of dissolved oxygen and carbon dioxide. This Fluosol emulsion is a mixture of perfluorodecalin and perfluorotripropylamine emulsified with Pluronic F68 and stabilized with egg yolk phosphatide. This emulsion is stored frozen until ready for use, at which time it is thawed and water, glycerol, solutes, glucose, and hydroxytethyl starch (an oncotic) are added.
DESCRIPTION OF THE PRIOR ART
U.S. Pat. No. 3,515,221 discloses apparatus for maintaining organs in a viable state for transplantation by perfusing a liquid through a cannula inserted into the blood vessel of an organ. The perfusate consists of a balanced salt medium containing dextran and sodium heparin buffered to a pH of 7.4 with tromethamine and sodium bicarbonate.
U.S. Pat. No. 3,734,851 which discloses a method and device for purifying blood by flowing animal blood over several semi-permeable membrances of a mixed esters of cellulose having an average pore size of 0.45 micron and a thickness of 150 microns. In one example of the invention a lyer of living liver cells are disposed between two of said membranes.
U.S. Pat. No. 4,186,565 discloses use of a membrane oxygenation in a portable preserving system using a perfusate.
LIST OF PUBLICATIONS
1. Converse J. Reconstructive Plastic Surgery. Philadelphia: Saunders, 1977. Chapter 86.
2. Crawford B. The management of tube pedicles. Br J Plast Surg 18:387, 1965.
3. Geyer R. Substitutes for blood and its components. Prog Clin Biol Res 19:1, 1977.
4. Baranowski J. Your hematocrit is zero, and you're doing fine. Diag Med :60, 1980
5. Riess J. Perfluoro compounds as blood substitutes. Angew Chem Int Ed Engl 17:621, 1978.
6. Sloviter H. Erythrocyte substitute for perfusion of brain. Nature 216:458, 1967.
7. Toyohua. H. Isolated heart perfusion with FC-43: an experimental study. Proceedings of the IVth International Symposium on PFC Blood Substitutes, Kyoto, 1978.
8. Andjus R. An isolated, perfused rat brain preparation, its spontaneous and stimulated activity. J Appl Physiol 22:1033, 1967.
9. Shindo K. Experimental studies on kidney preservation by perfusion with fluorochemical (FC-43) emulsion at room temperature. Proceedings of the IVth International Symposium on Perfluorochemical Blood Substitutes, Kyoto, 1978.
10. Geyer R. Perfluorochemical blood replacement preparations. Proceedings of the IVth International Symposium on Perfluorochemical Blood Substitutes, Kyoto, 1978.
11. Berkowitz H. Fluorochemical perfusates for renal preservation, J Surg Res 20:595, 1976.
12. Ohyanagi H. Experimental studies on kidney perfusion with perfluorochemical emulsion in view of graft survival. Proceedings of the IVth International Symposium on Perfluorochemical Blood Substitutes, Kyoto, 1978.
13. Ohyanagi H. Clinical studies of perflurorochemical whole blood substitutes: safety of Fluosol-DA (20%) in normal human volunteers. Clin Therap 2:306, 1979.
14. Tremper K. Hemodynamic and oxygen transport effects of a perfluorochemical blood substitute Fluosol-DA (20%). Crit Care Med 8:738, 1980.
15. Honda K. Clinical use of blood substitute. NEJM 303:391, 1980.
16. Finseth F. An experimental neurovascular island skin flap for the study of the delay phenomenon. Plast Recon Surg 61, 412, 1978.
17. Guba A. Regional hemodynamics of a pedicle flap: evaluation by distribution of radioactive microspheres. J Surg Re 25:274, 1978.
18. Pinggera W. The fiber dialyzer. J Extra-Corporeal Tech 4:6, 1871.
19. Gotch F. Chronic hemodialysis with the hollow fiber artificial kidney (HFAK). Trans Amer Soc Artif Intern Organs 15:95, 1969.
SUMMARY OF THE INVENTION
This invention relates to the use of perfluorocarbon emulsions, particularly, Fluosol-DA 20%, an artificial blood, for temporary tissue support of non-microvascular free flaps for keeping alive the flaps via an external circuit for a required time for revascularization thereby permitting transfer of the flap without a pedicle. The term "flap" as used herein is considered synonymous to a graft.
This invention further relates to the utilization of a cellulose matrix including a plurality of tubules of micron size as a tubular semi-permeable membrane disposed in direct contact with a viable tissue through which the fluorocarbon emulsion perfuses through prior to profusing into the flap or graft.
One advantage of the invention using perfluorcarbon emulsion perfusion is decreased operative time or the need for a skilled microvascular surgeon when utilizing microvascular techniques.
Another advantage of the invention is obviating the requirement for a searching for appropriate recipient vessels.
Still another advantage by the use of perfluorocarbon emulsions is in negating loss of flap from thrombosis since these emulsions do not clot.
Still another advantage of the invention is elimination of the need for dissection and canulation of the vessels in the flap and negation of loss of artificial blood by use of the cellulose semi-permeable membrane.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a circulatory system for keeping a flap or graft alive for surgical purposes of the invention.
FIG. 2 illustrates an enlarged view of a tubular semi-permeable membrane placed parallel to the skin surface between the dermis and muscle.
FIG. 3 graphically shows Vol. % O 2v . pO 2 in blood, Fluosol, and water.
DETAILED DESCRIPTION OF THE INVENTION
The invention relates to a system for keeping alive a flap or graft by perfusion of a fluorocarbon emulsion into the flap or graft as more fully described below.
A tubular semi-permeable membrane is obtained from a Cordis Dow 1.8D hemodialysis unit. Each unit includes over 13,000 tubules made of a thin-walled cellulose matrix, the internal diameter of the tubules is 200 microns with a wall thickness of 30 microns.
The perfluorochemicals in Fluosol-DA 20% set forth in Table 1 below, are emulsified for aqueous suspension into particles approximately 0.4 micron in diameter. These particles would not be expected to cross the tubular semi-permeable membrane described above. Thus the emulsified perfluorochemicals remain completely separate from the tissue during the flap perfusion studies.
TABLE 1______________________________________COMPOSITION OF FLUOSOL-DA______________________________________Perfluorodecalin 14.0 W/V %Perfluorotripropylamine 6.0 W/V %Pluronic F68 (emulsifier) 2.7 W/V %Yolk phospholipids (stabilizer) 0.4 W/V %Glycerol 0.8 W/V %NaCl 0.48 W/V %KCl 0.027 W/V %MgCl.sub.2 0.015 W/V %CaCl.sub.2 0.022 W/V %NaHCO.sub.3 0.168 W/V %Glucose 0.144 W/V %Hydroxyethyl starch (oncotic) 3.0 W/V %pH: 7.4-7.6______________________________________
PE 50 polyethelene tubing functions as an artificial capillary or "artery" and "vein" for delivering the perfuorocarbon emulsion to the tubular semi-permeable membrane. The tubular semi-permeable membrane was inserted within the polyethelene tubing for a distance of about one to two centimeters and adhesively secured in place with cyanoacrylic glue. The "arterial" side was secured preoperatively and then gas sterilized. When a flap of a rat was raised, a 23 gauge needle was placed within the flap through which was placed the artificial capillary. See FIG. 2. The needle was then removed. The artificial capillary was then placed about 1-2 cm inside a second length of sterile PE 50 polyethelene tubing acting as a "vein" and was glued in place with gas-sterilized cyanoacrylic glue. The polyethelene tubing was then sutured to the flap or graft to minimize traction on the glued connection. The artificial blood was oxygenated by feeding a mixture of 95% O 2 /5% CO 2 through conduit 1 into vessel 2 containing water to humidify the mixture which is then introduced into a 50 cc large reservoir 4 containing artificial blood 5 as shown in FIG. 1. Delivery pressure was controlled by gravity feed to be 100 cm H 2 O, the approximate mean arterial blood pressure in the rat. The artificial blood then went through a 20 micron filter 6 and into the flap 7. From the flap, the artificial blood then entered a 30 cc smaller reservoir 8 and was recycled by pump 9 to the reservoir 4. The bubbles of O 2 /CO 2 mixture were allowed to escape reservoir 4 via an overflow tubing 10 to the lower reservoir. From the lower reservoir, it was vented at the top of smaller reservoir 8 into the atmosphere. The hollow cellulose fiber of a Cordis Dow hemodialysis unit is used as the artificial capillary and eliminates the need for dissection and cannulation of vessels. Consequently, potential donor sites are unrestricted. The flap can be as small or as large as desired simply by adding more artificial capillaries as needed. No loss of artificial blood into the tissue occured since it remained in the artificial capillary and external circuit. Finally, since the artificial capillary was relatively large, embolized air passed freely through it and did not halt the perfusion.
In the invention described above four flaps were maintained in vitro using the Perfluorocarbon emulsion tissue (PET) support technique. After seven days of perfusion, the perfused flaps were histologically indistinguishable from freshly harvested skin and muscle, while a control non-perfused flaps showed advanced necrosis.
A 5×5 cm flap can be supported in its entirety by one tubule since enough diffusion of nutrients and waste products occurred over the 2.5 cm so that the tissue remained viable. The nutrient concentration of the perfluorocarbon emulsion is such that it is substantially the same as in arterial concentrations.
The capillaries described above were also embedded into the free flaps or grafts and perfused with fluorosol for seven (7) days and incubated at 98 degrees F. At the end of this time, the perfluorocarbon emulsion tissue supported skin and muscle flaps were histologically indistinguishable from freshly harvested skin and muscle.
To establish the superiority of the invention, tests have been conducted including absence of semi-permeable membranes and use of a polyethylene semi-permeable membrane as set forth below.
In these tests the tissue vasculature was used. The perfluorocarbon emulsion flowed into the artery and out the vein of a free axial pattern flap of an animal, e.g. rat.
Female Sprague Dawley rates were used (250-350 grams). All rats were anesthetized for surgery with Ketamine (87 mg/kg) and Zylazine (13 mg/kg) IM. The surgery was performed using aseptic technique.
Test I Vascular Tree
A. Axial Intact Group-Ten Rats
The inferior epigastric flap was used. The axial pattern flap was elevated superficial to the abdominal wall fascia and incorporated the panniculus carnosis. The flap measured 8 cm from xiphoid to pubis and 4 cm from umbilicus to the lateral change from thin abdominal skin to thick dorsal skin. The superior margin followed the rib cage and the inferior margin included the inguinal fat pad. The medial border was the abdominal midline. The inferior superficial epigastric artery and vein were left intact but the accompanying nerve was cut. The flap was sutured back in place with 5-0 steel.
B. Axial Ligated Group-ten rats
The inferior epigastric flap was raised as before but this time the inferior superficial epigastric vessels were ligated along with the accompanying nerve transection. The flap was sutured in place with 5-0 steel.
C. Blood Flow Estimation Group-two rats
In two rats the flap was raised as before and sutured loosely to its bed. The inferior superficial epigastric vessels were left intact. Radioactive microspheres were injected in the left ventricle via the right carotid artery. Shortly before, during, and shortly after the microsphere injection blood was withdrawn at the constant rate of 0.42 cc/min. from the left iliac artery. The radioactivity of the sample of blood was compared to the radioactivity of the raised flap. The blood flow to the flap was calculated using the formula:
Blood flow to the flap-0.42 cc/min.=Radioactivity count of flap-Radioactivity of blood sample.
D. Axial Perfusion Group-fifteen rats
The flap was raised as before. The nutrient inferior superficial epigastric artery and vein were transected and cannulated with PE 10 polyethelene tubing. The flap was removed from the rat and placed in a petri dish bathed in Euro-Collins Solution (see Table 2):
TABLE 2______________________________________Ingredients of Euro-Collins Solution per 100 cc______________________________________Dibasic Potassium Phosphate Anhydrous USP 740 mgMonobasic Potassium Phosphate, NF 205 mgPotassium Chloride, USP 112 mgSodium Bicarbonate, USP 84 mgGlucose (added) 5 mgpH 7.2______________________________________
(This solution is an approximation of intracellular fluid)
Perfusion of the artery and vein was attempted with the perfluorocarbon emulsion Fluosol-DA 20%.
E. Axial Delay Group-two rats
The flap was raised as before with the artery and vein left intact and the nerve transected. The flap was satured in place with 5-0 steel. At seven days in one rat and at nine days in the other, the axial vessels were ligated through a small groin incision.
Experiment II Artificial Capillary
A. Back Control Group-ten rats
A 2×2 cm square of skin and panniculus carnosus was elevated from the rat's back. The flap was taken in the midline, 10 cm from the occiput. After being completely detached from the rat, it was reversed so the hair was oriented toward the head and sutured in place with 5-0 Silk.
B. In Vitro Back Group-five rats
A square of skin and panniculus carnosus was elevated from the rat's back as described above. Three 2×2 cm square flaps were raised, one 3×3 cm flap and one 5×5 cm flap. Within these flaps, tubular semi-permeable membranes were placed parallel to the skin surface between the dermis and muscle. PE 50 polyethelene tubing acted as the "artery" and "vein" (see FIG. 2). The Table 3 shows the number and spacing of the tubules in each flap. Each flap was placed in a covered petri dish, raw surface down, bathed in a Euro-Collins Solution in which was added Penicillin G 100,000 u/L. The flap was then placed in an incubator at 98 degrees for seven days. Histologic sections were then taken for H and E staining.
TABLE 3______________________________________In Vitro Back Flap Trials SpacingBack Flap # of Tubules of Tubules______________________________________2 × 2 cm 4 4 mm2 × 2 cm 2 6 mm2 × 2 1 --3 × 3 1 --5 × 5 1 --2 × 1/3 × 1/5 × 1 cm none (control) --______________________________________
Oxygenated Fluosol-DA 20% was perfused through the tubules for the entire seven days. A control flap of skin and muscle was placed in a separate petri dish for each trial run and treated in the same way as the trial flap except that no tubule was placed and no Fluosol-DA 20% was perfused. The Euro-Collins Solution bath was drained and replaced everyday using sterile technique. The Fluosol-DA 20% and the oxygenation and pumping system tubing and reservoirs were replaced at three days with an identical fresh system.
C. In Vivo Back Group-fifteen rats
A 2×2 cm square of back skin and panniculus carnosus was completely elevated as before. One tubular semi-permeable membrane was placed transversely through the flap as in the vitro study. The flap was returned to the rat in reverse position so the hair was oriented toward the head. The PE 50 polyethelene tubing was tunneled to the nape of the neck where it entered the rat as the "artery" to the artificial capillary. From the other side of the artificial capillary a second polyethelene tubing was tunneled to the chest where it exited as the "vein." The Fluorosol-DA 20% perfusion was run as long as possible in an attempt to perfuse the flap for seven days. The Fluosol, tubing and reservoirs were again replaced at three days.
Rats cannot be immobilized for long periods of time without gastric ulceration and hemmorhage. Therefore, in order to protect the polyethelene catheters and allow for freedom of movement, stainless steel harnesses were attached to the chest and the nape of the neck with polyethelene bolts. The polyethelene tubing passed through the harnesses and entered a steel spring sheath. One sheath connected the nape of the neck to a swivel connector placed over the cage, another sheath connected the chest to a second swivel connector placed beneath the cage. These swivel connectors were specially made to allow for rotation of this tubing and sheath without undue tension on or twisting of the tubing.
RESULTS
Test I
A. Axial Intact Group: All flaps remained completely viable.
B. Axial Ligated Group: All flaps necrosed entirely. The flaps clinically remained unchanged until approximately day three. The flap was then noticeably darker and within several days it became frankly necrotic and was shed.
C. Blood Flow Estimation Group: In one rat the radioactivity count of the blood sample was 887 and the flap 447. In the second rat the counts were 960 and 482. This gives an average estimated blood flow of 0.2 cc/min to the flap in the anesthetized rats. (Each flap measured approximately 31 cm 2. The blood flow is calculated to be 0.007 cc/min/cm 2.)
D. Axial Perfusion Group: Cannulation of the inferior superficial epigastric vessels was difficult and rupture of the vessels was common. Attempted perfusion after vessel rupture caused immediate swelling of the areolar tissue and eventual perfusion stoppage. Eight flaps failed to be perfused in this way. Four flaps could not be perfused sufficiently to get an adequate venous return. Three flaps were perfused with adequate venous return but this was not sustained for more than two hours in any flap. At no time was the return flow rate greater than 0.1 cc/min. (Compare to estimated blood flow rate of 0.2 cc/min from the microphere studies).
E. Axial Delay Group: 80% of the flap survived subsequent ligation of the pedicle after seven days of revascularization and 85% after nine days as determined by the paper template method.
Test II Artificial Capillary
A. Back Control Group: All grafts necrosed. Discoloration was apparent on day five with frank necrosis noted on day twelve. Most grafts were shed by day sixteen.
B. In Vitro Back Group: All control flaps showed histologic changes consistent with advanced necrosis. Collagen staining in the dermis was diminished and there was evidence of disruption of the collagen matrix. The muscle layer showed disintegration of the fascicles and fragility to the staining process. On day two the 2×2 cm flap perfused with one tubule had three colonies of similar organisms, the largest of which grew directly over the tubule. These colonies were removed and the flap washed with the Euro-Collins Solution. The following day the perfusion was found to have stopped when the colonies had returned. The colonies were much greater in size, the one over the tubule, the largest, having digested into the flap and into the tubule. The perfluorocarbon emulsion had flowed out through the disruption and into the petri dish. This flap was excluded from the study. All the remaining flaps were perfused continuously for the full seven days. H and E stained histology at the end of seven days revealed normal architecture and staining characteristics. The dermal collagen was well organized and deeply stained. The muscle layer showed the normal peripheral nucleii and striations. As expected, there was no inflammatory response seen. A light blue staining of the collagen within 15 to 20 microns of the tubule was noted.
C. In Vivo Back Group: Despite the stainless steel harnesses, circular cages and swivel connectors, all but one of the rats were able to disrupt the perfusion in the first few days. This usually occurred as the rat awoke from anesthesis but in two cases disruption occurred at two days. The perfluorocarbon emulsion flowed out of the circuit and into the wound in all cases.
The flap was perfused for seven days in one rat. Unfortunately, the perfusion in this rat was not continuous. Interruptions of flow for up to three and four hours were common. In one instance, there was no perfusion for an estimated four to six hours. This occurred on day five. Usually the perfusion could be restarted using a normal saline flush. In two instances, the swivel connectors were clogged to such an extent that they had to be replaced with fresh connectors.
At one week, the control non-perfused grafts were discolored and eventual shedding of the graft could be anticipated. The perfused flap at one week, the end of the perfusion, looked entirely normal. By two weeks, most control flaps had been shed. The perfused flap was discolored and firm in its periphery but still intact. It did not look very much different from the control grafts at one week. By three weeks most controls had almost healed their ulcers. The perfused flap had begun to ulcerate and was totally shed by 22 days. (See Table 4 below).
TABLE 4______________________________________ Control Composite Graft Perfused Flap______________________________________Discoloration 3-5 days 10 daysFirst Ulceration 12-15 20Complete Ulceration 14-17 22Clinical appearance of back graft/flap______________________________________
DISCUSSION
Test I Vascular Tree
It was impossible to perfuse the free axial pattern flap selected as the model in this experiment. The inferior superficial epigastric vessels, which supply the inferior epigastric flap, are small delicate vessels in the rat. Cannulation was difficult and post-traumatic rupture common. High perfusion pressures were needed to get what flow was obtained, and as expected, this increased the likelihood of vessel rupture. The 0.2 cc/min flow rate to the inferior epigastric flap as determined by the microsphere study was not obtainable. Preopertive heparinization (50 units/kg IV) of the rat did not improve the poor flow rate.
Further research into the use of the tissue's own vascular tree as the delivery system for the artificial blood was abandoned for several reasons. If larger vessels were indeed necessary for adequate perfusion, then possible donor sites and flap size would be similar to that of microvascular free flaps. Dissection of the donor vessels would be the same as in the microvascular technique. Cannulation of the vessels, through easier than anastomosing them, is none the less difficult and exacting. In addition, the emulsion may leak out into the cut ends of the flap, in other words, bleed artificial blood, or may enter the host's vascular system as the revascularization of the flap progressed. Finally even a small amount of air embolization could immediately stop the flow permanently.
Test II The Artificial Capillary
The use of an artificial capillary was used to overcome the problems encountered with using the tissue's own vascular recipient bed is closer to that of the post-capillary (venous) rather than the pre-capillary (arterial) concentration. Also, in the clinical situation there is undoubtedly some interference with the diffusion by microhematoma formation in the graft-recipient bed interface. The nutrient concerntration of the perfluorocarbon emulsion is closer to arterial concentrations. For example, the calculated PO 2 of the perfluorocarbon emulsion equilibrated with 95% O 2 is 724 torr compared with 40 torr for venous blood. Since there is no blood flow in the detached flap, a hematoma between the flap tissue and the tubule would be unexpected.
Perfusion of the flap using the artificial blood/artificial capillary system (PET Support) was technically difficult in the in vivo rat model. Great pains were taken to protect the perfusion set-up from interference by the rat, but this was rarely possible. Disruption of the perfusion in the first few days was common. These perfusions did not support the free flap long enough to draw any conclusions as to the efficacy of PET Support in vivo.
In one rat the PET Support of the flap did last the required seven days. No biopsy of this flap was taken, so the vitality of the flap at the end of the perfusion could not be proven. Although the perfusion was discontinuous for four or five hours on Day 5 of the trial, the flap behaved as though its ischemic insult began at about the tree as the delivery system.
Perfusion of the flap using the artificial blood/artificial capillary system (PET Support) was technically difficult in the in vivo rat model. Great pains were taken to protect the perfusion set-up from interference by the rat, but this was rarely possible. Disruption of the perfusion in the first few days was common. These perfusions did not support the free flap long enough to draw any conclusions as to the efficacy of PET Support in vivo.
In one rat the PET Support of the flap did last the required seven days. No biopsy of this flap was taken, so the vitiality of the flap at the end of the perfusion could not be proven. Although the perfusion was discontinuous for four or five hours on Day 5 of the trial, the flap behaved as though its ischemic insult began at about the time the perfusion was halted at seven days.
The eventual loss of the PET Support flap can be explained in several ways. First, the perfusion was not continuous over the seven day period due to technical difficulties. This alone may have allowed early necrosis of the flap. Second, it can be postulated that a period of time longer than seven days may be necessary for vascular ingrowth, especially since the PET supported flap probably had a relatively PO 2 and low waste product concentration. Lacking these known stimulants for angiogenesis, the ingrowth of blood vessels may have been inhibited. It is also unknown what effect the lack of amino acids, vitamins, hormones and an active immune system had on the perfused flap and its ability to become revascularized.
PET Support has potential uses that could revolutionize the practice of Plastic Surgery. In addition to tissue transplantation, as in the non-necrovascular free flap, PET Support may also prove valuable in healing studies, in repair of avulsion injuries, such as the ear or nose, and in the salvage of failing conventional flaps.
The perfluorocarbon emulsion, Fluosol-DA 20%, a commerically available artificial blood substitute was used to nourish free flaps or graft in the rat model.
Two delivery systems were investigated, the tissue vasculature of a free axial pattern flap and a tubular semi-permeable membrane acting as an artificial capillary.
Adequate perfusion of the free axial pattern flap (the inferior epigastric flap), could not be accomplished. Since the artificial blood could not be perfused, it remains unanswered as to whether it could maintain the viability of this or any other free axial pattern flap.
It is to be understood that various changes may be made in the various parts and details without departing from the scope of the invention. | Apparatus and method for temporarily keeping alive animal flaps or grafts by perfusing artificial blood initially through a tubular semi-permeable membrance including a plurality of capillaries and thereafter perfusing the artificial blood into the flaps or grafts. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an oxide-superconducting coil, and especially, to a wind-and-react type coil using a metal sheathed oxide superconducting wire, and a method for manufacturing the same.
As methods for manufacturing an oxide superconducting wire, a powder-in-tube method, wherein superconducting powder, or a precursor of the superconducting powder, is filled in a metallic sheath, such as a silver tube, and the powder filled sheath is manufactured by a processing such as wire drawing, rolling, and other processes, or a dip-coat method, wherein a substrate is dipped into a suspended liquid containing superconducting powder continuously for coating both planes of the substrate with the suspended liquid, have been conventionally utilized. A superconducting coil using the superconducting wire manufactured by any one of the above methods, and manufactured by a wind-and-react (W & R) method, wherein a heat treatment is performed after fabrication of the coil, or a react-and-wind (R & W) method, wherein a heat treatment is performed prior to fabrication of the coil, has been reported to be able to generate a magnetic field of 3-4 T class under a condition of no backup magnetic field (Ookura et al.: Proceedings of The 53rd. 1995 Annual Meeting (Spring time) of the Cryogenic Engineering and Superconductor Society: D2-2 (1995)), and a magnetic field of 1-2 T under a backup magnetic field exceeding 20 T at 4.2 K (N. Tomita et al.: Appl. Phys. Lett., 65 (7), Aug. 15, 1994, p 898-900).
An oxide superconducting coil had problems such that high performance of the oxide superconducting coil estimated from characteristics of its short sample wire element could not be realized practically, on account of a large electromagnetic force under a strong magnetic field, a creep deformation by its own weight occurring during a heat treatment after fabrication of the coil, a thermal reaction of the superconducting core with an insulating material, and the like.
In detail, there were problems such as (1) breakage of the coil by the effect of an electromagnetic force of 40 MPa when the oxide superconducting coil was installed in an external magnetic field of 20 T and an electric current of 200 A was supplied thereto, (2) thermal creep deformation of the coil due to its own weight when a large scale coil was fabricated using the W & R method, and (3) deterioration of the superconductor in characteristics of the critical current density (Jc) caused by a reaction of the superconductor in the wire material core with a ceramic insulator, which was wound together with the superconductor in the wire material core, during heat treatment.
SUMMARY OF THE INVENTION
The present invention has been developed in consideration of the above problems. One of the objects of the present invention is to provide an oxide-superconducting coil in which can be deterioration of the characteristics in critical current density (Jc) by an electromagnetic force under a strong magnetic field can be prevented along with deformation and other reactions generated during heat treatment, and another object is to provide a method of manufacturing a coil having such qualities.
In order to manufacture a high performance oxide-superconducting coil, it is necessary to improve the mechanical strength of the superconducting coil at a temperature at which the coil is used, or which occurs during heat treatment of the coil, and to investigate the insulating material used in manufacturing the oxide-superconducting coil.
After serious investigation in consideration of the problems described above, the inventors of the present invention have developed an oxide-superconducting coil having the following composition.
The method of manufacturing the oxide-superconducting coil according to the present invention is characterized in the use of a heat resistant alloy, whereon an oxide film is previously formed by a heat treatment, as an insulating material when the coil is manufactured by the wind-and-react method, wherein heat treatment is performed after winding an oxide-superconducting powder filled metallic sheath and the insulating material together to form the coil.
Further, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that the heat resistant alloy has a sufficient mechanical strength at an elevated temperature for preventing creep deformation by the weight of the coil itself during the heat treatment, and a sufficient mechanical strength to withstand hoop stress by an electromagnetic force after cooling.
Furthermore, the method of manufacturing the oxide-superconducting coil according to the present invention is characterized in that silver or a silver alloy is arranged at an intermediate layer between the oxide-superconducting wire material and the heat resistant alloy of the oxide-superconducting coil, which is manufactured by winding an oxide-superconducting powder filled metallic sheath and an insulating material together.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that the heat resistant alloy used as the insulating material contains at least one of the metals selected from a group consisting of Ni, Cr, Cu, Nb, Mn, Co, Fe, Al, Mo, Ta, W, Be, Ti, and Sn, all of which have a low reactivity with the oxide-superconducting wire material.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that it can be used in a condition under an electromagnetic force exceeding 40 MPa.
Furthermore, the method of manufacturing the oxide-superconducting coil according to the present invention is characterized in that the widths of the oxide-superconducting wire material, the silver or the silver alloy, and the heat resistant alloy, which are wound together, coincide within a range of 5%.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that a heat treatment is performed, wherein a temperature difference between the inner plane and the outer plane of the coil is kept within a range of 2 degrees by providing a heater at the inside of the bobbin of the coil when the oxide-superconducting coil is manufactured by the method comprising the steps of winding the metallic sheathed oxide-superconducting wire material in a pan-cake shape, or a solenoid shape, and subjecting it to heat treatment.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that a heat resistant alloy or an insulating material composed of Al 2 O 3 as a main component is wound in a spiral shape together after winding a silver tape or a silver alloy tape onto a surface of the metallic sheathed oxide-superconducting flat square shaped wire material, or tape shaped wire material.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in winding the heat resistant alloy or an insulating material composed of Al 2 O 3 as a main component together in a spiral shape after adhering or joining a silver tape or a silver alloy tape onto a surface of the metallic sheathed oxide-superconducting flat square shaped wire material, or tape shaped wire material for forming a body.
Furthermore, the method of manufacturing an oxide-superconducting coil according to the present invention is characterized in that a heat resistant alloy is used as a material for the core of the coil.
The wire material used in manufacturing the oxide-superconducting coil according to the present invention is characterized in that it is manufactured by alloying an oxide-superconducting wire material coated with at least two kinds of different metals to each other by a heat treatment.
When the oxide-superconducting coil according to the present invention is used in a strong magnetic field, forming a complex superconducting magnet with a metallic group superconducting magnet cooled with liquid helium is effective, and characterized in that all the connecting points of oxide-superconducting current leads for supplying current from a power source to the magnet using permanent current switches composed of an oxide-superconducting coil are made superconducting.
As raw compounds for manufacturing the oxide-superconductor, for instance, in a case of a Y—Ba—Cu—O group, yttrium compounds, barium compounds and copper compounds are used. In a case of a Bi—Sr—Ca—Cu—O group, bismuth compounds, strontium compounds, calcium compounds and copper compounds are used, and depending on necessity, lead compounds and barium compounds are also used. In cases of a Tl—Sr—Ca—Cu—O group and a Tl—Ba—Ca—Cu—O group, thallium compounds, strontium compounds, barium compounds, calcium compounds and copper compounds are used, and depending on necessity, bismuth compounds and lead compounds are used. In order to enhance the crystal growth, sometimes, alkali earth metals, such as potassium compounds, are added. Furthermore, in cases using oxide superconductors, such as when a Hg group superconductor and an Ag group superconductor are used, compounds necessary for forming these superconductor are used. The above various raw compounds are used in forms of oxides, hydroxides, carbonates, nitrates, borates, acetates, and the like.
A method comprising the steps of pulverizing raw compounds, mixing the powder of raw compounds, and sintering the powder mixture is usable for producing oxide-superconducting powder. Among the above methods, any of the methods wherein the raw compounds are pulverized together, and wherein a part of the raw compounds are mixed previously and the rest of the raw compounds are mixed later, is usable.
The temperature for heat treatment in synthesis and intermediate sintering of the superconductor powder is in a range of 700-1200° C. In a process of heating the superconductor at a temperature exceeding the temperature causing a partial melting and subsequent cooling, which is performed depending on necessity, non-superconducting phases are dispersed intra-grains of the superconducting phase, and a non-magnetic heat resistance alloy is utilized at an outermost layer to strengthen the structure.
Several methods of manufacturing an oxide-superconducting wire material have been disclosed. Hereinafter, a wire drawing-rolling method will be explained in detail as an example.
After the oxide-superconductor, or its precursor, is synthesized according to the method described above, the oxide-superconductor is pulverized to powder having an average particle size of 0.001-0.01 mm in diameter and is filled into a metallic tube. Then, a wire drawing process with 5-20% cross section reduction is performed using draw benches, swaggers, cassette roller dies, or grooved rolls. Subsequently, if necessary, multifilamentary formation of the wire material is performed. A method of multifilamentary formation comprises the steps of inserting the superconducting wire material, which is drawn in a shape having a circular cross section or a hexagonal cross section, into metallic tube, and drawing the metallic tube with 5-20% cross section reduction to a desired diameter using an apparatus such as explained above. The processes used hitherto have the effects of forming the wire material in a desired shape and increasing the density of the superconducting powder filled in the metallic sheath.
In order to increase the density further, the wire material is manufactured using a cold roller or a hot roller to form a tape shaped wire material having a flat cross section. Then, the tape shaped wire material is treated thermally at an adequate temperature in a suitable atmosphere to obtain a wire material having a high critical current density. The inventors of the present invention have confirmed by experiments that, in order to obtain a wire material having a further high critical current density, it is effective to roll the wire material so that the elongation in a longitudinal direction of the wire material is restricted to as small a value as possible, and the elongation in a lateral direction of the wire material is enhanced as much as possible. This is because densification of the superconducting core is enhanced. Depending on its usage, a wire material having a circular cross section itself may be used without performing the rolling.
As an adequate temperature for final heat treatment of the oxide-superconducting wire material, a temperature within a range of 700-1050° C. is used. The wire material is utilized in the form of a coil wound with a complex wire made up of at least two wires, or is formed in a shape of lead wires or a cable wire material, depending on its usage. In order to improve the characteristics of the superconductor by heat treatment, the atmosphere during heat treatment is selected depending on the kind of material. For instance, when a Bi 2 Sr 2 Ca 1 Cu 2 O x group superconductor is used, a low pressure oxygen atmosphere (for example, 1-20 vol. % O 2 ) is selected at the final heat treatment for obtaining high performance characteristics. However, in the case of a Tl 2 Ba 2 Ca 2 Cu 3 O x group superconductor, a pure oxygen atmosphere is selected, for example, because the higher the oxygen partial pressure is, the more the characteristics can be improved. In addition to the method explained above, an equivalent value can be obtained by using any wire materials manufactured by, for instance, a thermal spray method, a doctor-blade method, a dip-coat method, a screen print method, a spray pyrolysis method, a jelly roll method, and the like.
As material for the sheath and the substrate of the superconducting wire material, Ag, Au, Pd, Pt, a silver alloy containing 1-50 wt. % of Au, and Ag or a silver alloy containing 1-50 wt. % of Pd, Mg, Ti, Mn, Ni, and Cu, which do not necessitate considering any corrosion problem at the heat treatment, are mainly used. If necessary, a non magnetic heat resistant alloy is used at the outer most layer.
The insulating material which is wound with the oxide-superconducting wire material must be wound densely in view of coil design for obtaining generation of a high magnetic field. Therefore, the thickness of the insulating layer must be decreased desirably to 0.3 mm, and preferably to 0.1 mm, at the utmost. Naturally, the insulating material may not be allowed to deteriorate the superconducting characteristics after the heat treatment, but, additionally, it is important that the insulating material have as preferable insulating capability, a strong adhesiveness, a sufficient strength, and a preferable heat resistance.
In accordance with the present invention, a superconducting magnet, which generates a significantly strong magnetic field, can be realized by composing a structure with oxide-superconducting coils which are provided at the inner layer of a metallic group superconducting magnet. As the metallic group superconductor, any one of a NbTi group alloy, a Nb 3 Sn group alloy, a Nb 3 Al group alloy, a V 3 Ga group alloy, and a Chevrel group compound may be used, and, if necessary, at least two kinds of magnets are employed. The oxide-superconductor arranged at the inner layers is preferably one of the bismuth group superconductors. If the oxide-superconductor is a pan-cake shape coil and the characteristics of the respective coils vary somewhat, the high performance coils are arranged at a middle portion in a longitudinal direction of the coil, where the magnetic field is higher than that at both end portions. In accordance with this arrangement, a superconducting magnet capable of generating a strong magnetic field exceeding 18 T can be readily obtained.
The conductor manufactured to a desired structure by the method explained above is further fabricated in the form of a coil, current lead, cable, and the like, and a heat treatment is performed after winding. The superconducting wire material can be used for cables, current leads, an MRI (Magnetic Resonnance Imager) apparatus, a NMR (Nuclear Magnetic Resonnance) apparatus, a SMES (Superconducting Magnetic Energy Storage) apparatus, superconducting generators, superconducting motors, a magnetic levitation train, superconducting electromagnetic propulsion ships, superconducting transforms, and the like. The superconducting wire material is more advantageous if its operating temperature is higher than the temperature of liquid nitrogen.
In accordance with the method of the present invention for manufacturing an oxide-superconducting coil, the problem of the Jc characteristics being deteriorated by an electromagnetic force under a strong magnetic field, and the problem of deformation generated in a heat treatment process, other reactions, and the like can be solved. The heat resistant alloy used as the insulating material of the oxide-superconducting coil generally has a preferable workability. Accordingly, an advantage, in that a superconductor occupying volume fraction in a coil is readily increased in comparison with a tape shaped or fibrous ceramic insulating material, is realized
The problem of the superconducting characteristics being deteriorated by components in the core of the superconducting wire material and components contained in the heat resistant alloy can be solved by manufacturing an oxide-superconducting coil wherein silver or a silver alloy is arranged at an intermediate layer of the heat resistant alloy, which is would together with the metallic sheathed superconducting wire material.
In view of the winding operation of a coil, especially a pan-cake shaped coil, the widths of the superconducting wire material, the silver or the silver alloy tape, and the heat resistant alloy desirably should coincide with each other within a range of 5%. For instance, if the width of the wire material is 5 mm, the other members desirably have a width in a range of 4.75 mm-5.25 mm.
Regarding the heat treatment of the coil, the inventors of the present invention have confirmed by experiments that fluctuation of the critical current density of the coil can be significantly suppressed by maintaining a temperature difference between a point at the inner plane and a point at the outer plane of the coil within 2° C. with a heater which is provided inside the core of the coil.
The problem of the reaction of the components in the superconducting core with the components contained in the heat resistant alloy can be solved by winding the coil after winding an insulating material, which contains silver or a silver alloy tape, a heat resistant alloy, or Al 2 O 3 as a main component, in a spiral manner on the surface of the superconducting flat square wire material, or superconducting tape wire material.
Extending the alloy sheathed wire material in the order of kilometers became possible by manufacturing the alloy sheathed superconducting wire material, which was alloyed by a heat treatment, with an oxide-superconducting multifilamentary wire material coated with at least two different kinds of metals. In view of an application to a current lead and others, it is necessary to alloy the sheath material for making the material highly resistant. However, in a case when an Ag—Au alloy is used in a process for manufacturing the multifilamentary wire material by a powder in tube method, there has been a problem in that, if the Ag—Au alloy sheath is used from the step of the filling powder operation, the sheath material becomes hardened and a breakage of the wire material occurs during the processing. In consideration of the above problem, a long extension of the wire material became possible by using an Ag sheath for the sheath material to be filled with the powder and an Au sheath for the sheath material to be inserted with the Ag sheathed single core wire obtained by drawing the above powder filled Ag sheath, combining the above sheath materials so as to be a desired composition and proportion, and alloying the sheaths by a heat treatment.
Further, in a superconducting magnet system, wherein a complex superconducting magnet comprising a metallic superconducting magnet cooled with liquid helium and an oxide-superconducting coil generates a magnetic field exceeding 18 T, and an oxide superconducting current lead and a permanent current switch comprising an oxide-superconducting coil are provided thereto, it is advantageous if all the junctions are composed of superconducting connections. In the above case, decreasing the number of the junctions among the oxide-superconducting coils arranged in the inner layer of the superconducting magnet, the oxide-superconducting lead, and the permanent current switch as much as possible can reduce the connection resistance. Therefore, the above members are desirably composed of an integrated body.
In accordance with the above superconducting magnet system, loss of the liquid helium can be reduced, and a high efficiency can be realized. Either of a thermal switch to heat or a magnetic switch to add a magnetic field can be used as the above permanent current switch.
When winding a coil by a W & R method, wherein a heat treatment is performed after the winding, the superconducting characteristics may be deteriorated by a reaction of a superconducting wire material and an insulating material during the heat treatment, if a conventional ceramic unwoven cloth or fiber is used as the insulator the coil. The reason is that the conventional ceramic unwoven cloth or fiber contains about 50 wt. % SiO 2 , which is acidic, and the insulator readily reacts with an alkali earth metal such as Sr, Ca, and the like in the superconducting wire material.
Therefore, the insulator used between each of the turns of the wire material is desirably a ceramic unwoven cloth or fiber containing at least a single kind of heat resistant oxide having an oxygen ion intensity ratio in a range of 0.5-2.5 by 90-100 wt. % content. The oxygen ion intensity ratio is an index of an intensity determined by the number of charges and the radius of the ion. Generally speaking, basic oxides having small oxygen ion intensity ratios, or acidic oxides having large oxygen ion intensity ratios, are inactive to each other, and a basic oxide and an acidic oxide are significantly reactive to each other. A reaction which practically occurs at the coil is assumed to react through a pin hole of the sheath, which may have been formed during the manufacturing process.
In accordance with the present invention, it is possible to manufacture an oxide-superconducting coil, which is prevented from experiencing deterioration of the Jc characteristics caused by an electromagnetic force in a strong magnetic field, and reactions and deformation at heat treatments, and can achieve 100% performance of wire elements even after being formed in the shape of a coil.
BRIEF DESCRIPTION OF THE DRAWINGS
these and other objects, features and advantages of the present invention will be understood more clearly from the following detailed description when taken with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic perspective illustration of an oxide-superconducting coil;
FIG. 2 is a schematic cross section of an oxide-superconducting coil taken on line A-A′ in FIG. 1;
FIG. 3 is a schematic cross section of a single pancake coil wherein a reinforcer is interposed;
FIG. 4 is a schematic perspective illustration of an oxide-superconducting coil;
FIG. 5 is a schematic cross section of an oxide-superconducting coil;
FIG. 6 is a schematic cross section of a double pancake coil wherein a reinforcer is inserted;
FIG. 7 is a graph indicating a critical current distribution in a coil wherein a heater is provided inside the core of the coil;
FIG. 8 is a graph indicating a critical current distribution in a coil manufactured by a conventional heat treating furnace; and
FIG. 9 is a schematic cross section of a superconducting magnet system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of the present invention will be explained with reference to the drawings.
Embodiment 1
Respective Bi 2 O 3 , SrO, CaO, and CuO oxides were used as a starting material and weighed so that the atomic mole ratio of Bi:Sr:Ca:Cu became 2.00:2.00:1.00:2.00. Then, a Bi-2212 superconducting powder was obtained by the steps of adding pure water to the weighed oxides, mixing the oxides by centrifugal ball milling for one hour, dehydrating and drying the mixture, and heat treating the dried mixture at 840° C. for 20 hours in a suitable atmosphere. As a result of observation by powder X-ray diffraction and a scanning electron microscope, other phases such as SrO, and CuO from a superconducting phase were somewhat observed.
The obtained powder was further pulverized by a grinder in an argon atmosphere to be, at the utmost, 0.01 mm in average diameter, and then, it was filled into an Ag tube of 6.0 mm in outer diameter and 5.0 mm in inner diameter. Subsequently, the Ag tube was drawn with a cross section reduction rate of 11-13% by a draw bench so as to be 1.03 mm in outer diameter. The Ag tube was cut into 19 equal length wires. After inserting the 19 wires into an Ag tube of 6.0 mm in outer diameter and 5.2 mm in inner diameter, the tube was cold drawn with a cross section reduction rate of 11-13% using a draw bench and a roller and finally a Bi-2212/19 multifilamentary tape-shaped Ag sheathed wire material 0.11-0.13 mm thick, 4.8-5.2 mm wide, and 50 m long was obtained. During above manufacturing operation of the single core and the multifilamentary wire material, an annealing treatment at 350° C. for 30 minutes was performed arbitrarily 1-3 times.
As shown in FIG. 1, the obtained Bi-2212 oxide superconducting wire material 1 and a hastelloy X tape 2 , which was 0.03 mm thick and 5.1 mm wide, and which was previously heat treated at 800° C. to form an insulating film on its surface, were wound around an Ag ring 3 serving as a core, in a pancake shape while adding a tensile force of 10 kgf/mm 2 to the wire material 1 and of 20 kgf/mm 2 to the hastelloy X tape 2 , respectively, to form a pancake coil 45 mm in outer diameter. A cross section of the coil taken on line A-A′ in FIG. 1 is schematically shown in FIG. 2 . The resistivity of the insulator was in the order of MΩs, and the insulation of the coil was sufficient.
The manufactured coil was heated to 880° C. for 4 hours in a pure oxygen atmosphere, kept at 880° C. for 10 minutes for a heat treatment of partial melting, cooled to 815° C. with a velocity of 0.25° C./minutes, and then, cooled to room temperature in 3 hours. Furthermore, in order to enhance the superconducting characteristics, an annealing treatment was performed at 800° C. for 20 hours in a low pressure oxygen atmosphere (4 vol. % O 2 ), and a Bi-2212 superconducting coil was obtained. In accordance with the above method, six pancake coils were manufactured. The six coils were piled on one another, and an adhesion treatment by diffusion joining at 800° C. for 10 hours was performed. At the joining portion, three Bi-2212 superconducting tape wires were used. After the heat treatment, a current of 10 A was supplied at room temperature. The generated magnetic field coincided with the design value. Accordingly, a short circuit between coils and between wire material did not exist. No change between the shapes of the coil before and after the heat treatment was observed, nor was any deformation by thermal distortion observed.
The critical current of short length (50 mm) wires, which were thermally treated simultaneously, in a zero magnetic field was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 95 A at 20 K and 134 A at 4.2 K. In this case, the criterion for the critical current was 1 μV/cm.
The critical current of the coil in a zero external magnetic field was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 82 A at 20 K, and 105 A at 4.2 K. The reason for the low characteristics of the coil is assumed to be due to the influence of a self induced magnetic field. In this case, the criterion for the critical current was 1×10 −13 Ω.m.
Then, the critical current of the coil in an external magnetic field of 21 T was determined by the four probe method for resistivity measurement at 4.2 K. Simultaneously, the magnetic field generated at the center of the coil was determined by using a Hall element. The result was 50 A at 4.2 K, and the generated magnetic field observed was 0.83 T. The values coincided with design values. The maximum electromagnetic force added to the oxide superconducting coil was 50 MPa.
After the measurement, the coil was examined visually. No deformation by the electromagnetic force or by the cooling was observed.
Embodiment 2
Six stacked bi-2212 superconducting coils were manufactured by the same method as the embodiment 1 except for replacing the insulating material of the pancake coil in the embodiment 1 with 97 wt. % Al 2 O 3 containing insulating paper 0.1 mm thick and 5.05 mm wide.
The six coils were stacked on one another, and an adhesion treatment by diffusion joining at 800° C. for 10 hours was performed. At the joining portion, three Bi-2212 superconducting tape wire were used. No deformation of the coil shape was observed in a visual inspection of the coil after the heat treatment. By supplying a current of 10 A at room temperature, a magnetic field of 97% design value was generated.
The critical current of the coil in a zero external magnetic field was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 81 A at 20 K, and 117 A at 4.2 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
Then, the critical current of the coil in an external magnetic field of 21 T was determined by the four probe method for resistivity measurement at 4.2 K. Simultaneously, the magnetic field generated at the center of the coil was determined by using a Hall element. The result was 12 A at 4.2 K, and the gradient of the voltage rise in a V-I curve was moderate.
In a visual inspection of the coil after the measurement, an apparent deformation by the electromagnetic force was observed.
Embodiment 3
Bi-2212 superconducting powder obtained by the same method as the embodiment 1 was filled into an Ag tube 6.0 mm in outer diameter and 5.0 mm in inner diameter. Subsequently, the Ag tube was drawn with a cross section reduction rate of 11˜13% using a draw bench, and finally was drawn with a hexagonal die, of which the longest diameter was 0.96 mm. The obtained wire was cut into 55 equal length wires. After inserting the 55 wires and six Ag wires 0.5 mm in outer diameter into an Ag tube 8.3 mm in outer diameter and 7.2 mm in inner diameter, the tube was cold drawn with a cross section reduction rate of 11˜13% using a draw bench and a roller, and finally a Bi-2212/55 multifilamentary tape-shaped Ag sheathed wire material 0.11˜0.13 mm thick, 4.8˜5.2 mm wide, and 50 m long was obtained. During the above manufacturing operation of the single core and the multifilamentary wire material, an annealing treatment at 350° C. for 30 minutes was performed arbitrarily 1˜3 times.
Twelve pancake coils of 100 mm in outer diameter as shown in FIG. 1 were manufactured by the same method as the embodiment 1 using the obtained Bi-2212 oxide superconducting wire material 1 and a Haynes alloy (No. 230) tape, i.e. a heat resistant alloy 2 , 0.03 mm thick and 5.2 mm wide, which was previously heat treated at 800° C. to form an insulating film on its surface. The resistivity of the insulator was in the order of MΩs, and the insulation of the coil was sufficient.
After manufacturing twelve coils, the coils were divided into six pairs, two coils each. Two coils in a pair were connected inside the core 3 using three Bi-2212 oxide-superconducting wires for the connection 4 to form a double stacked pancake coil, respectively. Subsequently, the six double stacked pancake coils were stacked and an adhesion treatment for the outer portion of the coils was performed by diffusion joining at 800° C. for 10 hours.
In the present embodiment, a SUS 310 strip 5 0.1 mm thick, i.e. a heat resistant alloy 5 having an oxide film formed on its surface, was interposed between respective coils as shown in FIG. 3, and then a heat treatment was performed. After the final heat treatment, a current of 10 A was supplied at room temperature. The generated magnetic field coincided with the design value. Accordingly, it could be assumed that a short circuit between coils and between wire material did not exist. No change between the shapes of the coil before and after the heat treatment was observed, nor was any deformation by thermal distortion observed. Accordingly, it was revealed that the total load of the coil was supported by the core and the SUS strip.
The critical current of short length (50 mm) wires, which were thermally treated simultaneously, in a zero magnetic field was determined by a four probe method for resistivity measurement at 4.2 K. The result was 122 A at 4.2 K. In this case, the criterion for the critical current was 1 μV/cm.
Further, the critical current of the coil in a zero external magnetic field was determined by a four probe method for resistivity measurement at 4.2 K. The result was 96 A at 4.2 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
Then, the critical current of the coil in an external magnetic field of 18 T was determined by the four probe method for resistivity measurement at 4.2 K. Simultaneously, the magnetic field generated at the center of the coil was determined by using a Hall element. The result was 44 A at 4.2 K, and the generated magnetic field observed was 2.2 T. The value coincided with the design value. The maximum electromagnetic force added to the oxide-superconducting coil was 43 MPa.
After the measurement, the coil was examined visually. No deformation by the electromagnetic force or by the cooling was observed.
Embodiment 4
Twelve stacked Bi-2212 superconducting coils were manufactured by the same method as the embodiment 2 except for replacing the insulating material in the pancake coil of the embodiment 3 with ceramics insulating tape (70 wt. % Al 2 O 3 - 30 wt % SiO 2 ) 0.1 mm thick and 5.05 mm wide, and using no SUS strip between the coils.
The twelve coils, i.e. six pairs, two coils each, were stacked, and an adhesion treatment was performed by diffusion joining at 800° C.10 hours. Three Bi2212 superconducting tape wires were used at the joining portion. As a result of visual inspection of the coil after the heat treatment, a slight creep deformation caused by the coil's own weight was observed. A tendency was observed that the deformation became larger at the outer position of the coil than at the inner position of the coil. In comparison with the embodiment 3, it was revealed that the weight of the coil itself could not be supported because use of the heat resistant alloy was omitted.
The critical current of the coil was determined by supplying a current of 10 A at room temperature, and generation of only 60% of the design magnetic field was observed. The reason was assumed to be a short circuit caused by deformation of the coil accompanied by a sealing up of the coil. A result of a visual inspection of the wire material after disassembling the coil from a terminal end at the outer portion revealed that a short circuit was generated at the outer portion of the coil, where the deformation during the heat treatment was large.
Embodiment 5
A pancake coil was manufactured as shown in FIG. 4, wherein an Ag-0.2 wt. % Mg alloy tape 7 0.04 mm thick and 5.0 mm wide was interposed at an intermediate layer between a Bi-2212/19 multifilamentary tape shaped Ag sheathed wire obtained by the same method as the embodiment 1 and a hastelloy X tape 0.03 mm thick and 5 mm wide, i.e. a heat resistant alloy 6 whereon no oxide film was formed. In accordance with the present embodiment, the Ag-0.2 wt. % Mg alloy tape 7 was wound on the surface of the Bi-2212 wire material 1 in a spiral manner, and further, the hastelloy X tape, i.e. a heat resistant alloy 6 whereon no oxide film was formed, was wound together therewith. A schematic cross section of the coil is shown in FIG. 5 .
The obtained pancake coil was thermally treated in the same manner as the embodiment 1, and a Bi-2212 superconducting coil 80 mm in outer diameter was manufactured. After manufacturing 10 coils in the same manner, the coils were stacked to form a 10 stage coil. Between respective ones of the coils, a Haynes alloy plate 4 of 0.1 mm thickness was interposed between coils. The shapes of the coils before and after the heat treatment did not show any change similar to the embodiment 1. A current of 10 A was supplied to the coil at room temperature, and a coincident magnetic field at the design value was generated. Accordingly, no short circuit was recognized.
The critical current of short length (50 mm) wires, which were thermally treated simultaneously, in a zero magnetic field was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 116 A at 20 K and 157 A at 4.2 K. In this case, the criterion for the critical current was 1 μV/cm.
Further, the critical current of the coil in a zero external magnetic field was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 94 A at 20 K and 134 A at 4.2 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
Then, the critical current of the coil in external magnetic fields of 18 T and 21 T was determined by the four probe method for resistivity measurement at 4.2 K. Simultaneously, the magnetic fields generated at the center of the coil were determined by using a Hall element. As for the results, the critical current at 18 T was 73 A, and at 21 T it was 70 A. The generated magnetic fields were 2.02 T and 1.94 T, respectively. The values coincided with the design values. The maximum electromagnetic force added to the oxide-superconducting coil was 45˜55 MPa.
After the measurement, the coil was inspected visually, and no deformation was observed.
In the present embodiment, the heat resistant alloy tape, whereon no oxide film was formed, was used for insulating the coil. However, the same result can be naturally obtained if a heat resistant alloy tape, whereon an oxide film is formed, is used.
Embodiment 6
A pancake coil was manufactured by the same method as the embodiment 3 except no Ag-0.2 wt. % Mg alloy tape was used at the intermediate layer of the pancake coil as in the embodiment 5. Subsequently, the same heat treatment as the embodiment 1 was performed to obtain a Bi-2212 superconducting coil.
The critical current of the coil in zero external magnetic fields was determined by a four probe method for resistivity measurement at 20 K and 4.2 K. The results were 61 A at 20 K and 75 A at 4.2 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
A result of a visual inspection of the wire material after disassembling the coil from a terminal end at the outer portion revealed that a reaction had occurred between the superconducting wire material and the Hastelloy X tape. The reason for this can be supposed to be that the Hastelloy X tape absorbed oxygen from the superconductor when the oxide film was formed on the surface of the Hastelloy x tape by the heat treatment.
Embodiment 7
Respective Bi 2 O 3 , PbO, SrO, CaO, and CuO oxides were used as a starting material and were weighed so that the atomic mole ratio of Bi:Pb:Sr:Ca:Cu became 1.74:0.34:2.00:2.20:3.00. Then, a Bi-2223 superconducting precursor was obtained by the steps of adding ethyl alcohol to the weighed oxides, mixing the oxides by centrifugal ball milling for one hour, dehydrating and drying the mixture, and heat treating the dried mixture at 790° C. for 20 hours in the atmosphere. As a result of observation by powder X-ray diffraction and a scanning electron microscope, a main component of the obtained powder was revealed to be Bi-2212 phase. Additionally, another substance containing Sr-Ca-Cu-O, which could not be determined, and SrO, CuO, Ca 2 PbO 4 , and the like were detected.
The obtained powder was further pulverized by a grinder to be, at the utmost, 0.01 mm in average diameter, and then, it was filled into an Ag tube 6.0 mm in outer diameter and 4.5 mm in inner diameter.
The tube was manufactured in the same manner as in the embodiment 1, and finally a Bi-2223/19 multifilamentary tape-shaped Ag sheathed wire 0.5 mm thick, 2.6 mm wide, and 30 m long was obtained.
The wire material was wound around a drum made of SUS having an outer diameter of 50 cm, and a heat treatment was performed at 838° C. for 50 hours in an atmosphere using a large scale electric furnace. During the heat treatment, the temperature distribution was controlled to be within 2° C. After the heat treatment, the wire material was drawn to be 0.3 mm thick, and again a heat treatment at 838° C. for 50 hours was performed. Similarly the steps of drawing the wire material to 0.2 mm in thickness performing the heat treatment, and drawing the wire material again to be 0.11˜0.13 mm thick were performed. The width of the wire material was in a range of 4.8˜5.2 mm.
A double pancake coil as shown in FIG. 4 was manufactured using the obtained Bi-2223 oxide superconducting wire material 1 and a Haynes alloy (No. 230) 2 which was 0.05 mm thick and 5.1 mm wide, i.e. a heat resistant alloy 2 which was previously treated thermally at 650° C. for 5 hours in an oxygen atmosphere to form an oxide film on its surface. A tensile force of 5 kgf/mm 2 was added to the oxide superconducting wire material 1 and a tensile force of 40 kgf/mm 2 was added to the Haynes alloy (No. 230) tape in the winding operation to form a double pancake coil 80 mm in outer diameter and 10.5 mm wide. In the present embodiment, a SUS 310 core 30 mm in outer diameter and 10.5 mm high was used as the coil core 3 . A hastelloy strip as shown in FIG. 6, i.e. a heat resistant alloy 5 whereon an oxide film was formed, was interposed at the middle in the longitudinal direction of the double pancake coil. The oxide film on the surface of the hastelloy was previously formed.
The manufactured coil was treated by heating at 835° C. for 50 hours in a 20 vol. % O 2 atmosphere, and a Bi-2223 superconducting coil was obtained. The appearance of the obtained coil after the heat treatment indicated no change in comparison with the appearance before the heat treatment. A current was supplied to the coil at room temperature, and the generated magnetic field coincided with the design value. Accordingly, a short circuit between coils and between wire material was not recognized.
The critical current of short length (50 mm) wires, which were thermally treated simultaneously, in a zero magnetic field were determined by a four probe method for resistivity measurement at 77 K and 63 K. The results were 14 A at 77 K and 27 A at 63 K. In this case, the criterion for the critical current was 1 μV/cm.
The critical current of the coil in a zero external magnetic field was determined by a four probe method for resistivity measurement at 77 K and 63 K. The results were 10 A at 77 K and 22 A at 63 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
The reason why the characteristics of the coil were lower than that of the short length wire material is assumed to be due to the influence of a self induced magnetic field of the coil.
When any one of Ag, hastelloy X, and Haynes alloy (No. 230) was used as the material for the coil core, the same value in the characteristics of the coil was obtained.
Embodiment 8
A single pancake coil as shown in FIG. 1 was manufactured using the Bi-2223/19 multifilamentary tape shaped Ag sheathed wire material 1 obtained by the same method as the embodiment 7 and a Haynes alloy (No. 230) 2 . An Ag ring was used as the coil core 3 . The shape of the coil was 80 mm in outer diameter and 30 mm in inner diameter. A voltage terminal was inserted at every 1 meter of the wire material during the winding operation.
The manufactured coil was thermally treated at 835° C. for 50 hours in a 20 vol. % O 2 atmosphere, and a Bi-2223 superconducting coil was obtained. At the heat treatment, a heater was provided at the inner portion of the coil core, and the temperature was controlled so that the temperature difference between the outer portion of the coil and the inner portion of the coil was within 1° C. The obtained coil indicated no change in the shape before and after the heat treatment, nor any thermal distortion.
The critical current between terminal ends of the coil in a zero magnetic field was determined by a four probe method for resistivity measurement at 77 K and 4.2 K. The results were 15 A at 77 K and 55 A at 4.2 K. In this case, the criterion for the critical current was 1×10 −13 Ω·m.
Then, the critical current between the voltage terminals inserted at every 1 meter of the wire material in a zero magnetic field was determined at 4.2 K for investigating a distribution of the critical current. As a result, it was revealed that the critical current of the coil was distributed to within 4%.
The appearance of the coil was visually inspected after the heat treatment, and no deformation was observed.
The distribution of the critical current of the coil is summarized in FIG. 7 .
Embodiment 9
Bi-2223 double pancake coils were manufactured in the same manner as the embodiment 8 except that no heater was provided at the inner portion of the coil core in the heat treatment of the superconducting coil as in the embodiment 8.
The critical current between terminal ends of the coil in a zero magnetic field was determined by a four probe method for resistivity measurement at 77 K and 4.2 K. The results were 13 A at 77 K and 50 A at 4.2 K.
Then, the critical current between the voltage terminals inserted at every 1 meter of the wire material in a zero magnetic field was determined at 4.2 K for investigating a distribution of the critical current. As a result, it was revealed that the critical current of the coil was distributed as wide as 20%.
The appearance of the coil was visually inspected after the heat treatment, and no deformation was observed.
The distribution of the critical current of the coil is summarized in FIG. 8 .
Embodiment 10
Bi-2223 precursor obtained by the same method as the embodiment 7 was filled into an Ag tube 6.0 mm in outer diameter and 4.0 mm in inner diameter. Subsequently, the Ag tube was drawn with a cross section reduction rate of 11˜13% by a draw bench, and finally a wire drawn to 1.03 mm in outer diameter. The obtained wire was cut into 19 equal length wires. After inserting the 19 wires into an Au tube 6.0 mm in outer diameter and 5.75 mm in inner diameter, the tube was processed repeatedly by drawing and heat treatment, and finally a Bi-2223/19 multifilamentary Ag-Au alloy sheathed wire material 0.11˜0.13 mm thick, 4.8˜5.2 mm wide, and 90˜100 m long was obtained. The alloy sheath composition after the heat treatment was Ag-17 wt. % Au. The core ratio of the wire material was 20%.
Embodiment 11
Bi-2223 precursor obtained by the same method as the embodiment 7 was filled into an Ag-17 wt. % Au alloy tube of 6.0 mm in outer diameter in a 19 cores condition with a core ratio of 20%, and subsequently, the alloy tube was drawn with a cross section reduction rate of 11˜13% by a draw bench. However, breakage of the wire material occurred very often during the manufacturing of the single core wire, and no wire material of more than 5 meters could be obtained.
Embodiment 12
A complex superconducting magnet was manufactured, where a Bi-2212 group oxide superconducting coil 10 was arranged inside a NbTi superconducting magnet 8 and a Nb 3 Sn superconducting magnet 9 , which were cooled by liquid helium, as shown in FIG. 9 . Briefly speaking, the structure of the magnet shown in FIG. 9 was composed of the Nb 3 Sn superconducting magnet 9 wound as a concentric circle and arranged at the inside of the NbTi superconducting magnet 8 wound as a concentric circle, and further, the Bi-2212 group oxide superconducting coil 10 wound as a concentric circle was arranged at the inside of the Nb 3 Sn superconducting magnet 9 wound as a concentric circle. The heights of the magnets were designated so that the inner magnet had a lower height than that of the outer magnet. All of those were solenoid wound magnets.
The superconducting coils were fixed in a cryostat 11 , and a control current was supplied through a current lead from an external power source. A hastelloy X tape formed with an insulating film thereon as explained for the embodiment 1 was used for the insulation between the coils of the Bi group oxide superconducting coil 10 . At both ends of the Bi group oxide superconducting coil 10 , a current lead 12 composed of Bi-2223 was connected superconducting by diffusion welding. The one end of the respective NbTi superconducting magnet 8 and the Nb 3 Sn superconducting magnet 9 were connected mutually in a normal conducting condition 13 by soldering, and current to the magnets was supplied through copper leads 14 .
In order to make it possible to operate a permanent current mode, a permanent current switch 15 composed of a Bi-2212 group superconducting coil was installed. The permanent current switch 15 was connected superconductingly with a current lead.
The complex superconducting magnet generated a magnetic field of 23.5 T, and no problem was experienced during continuous operation for three months. By using the oxide superconductor for the permanent current switch as explained above, the stability increased because the temperature margin was higher than that of a conventional metallic group superconductor, and generation of a quench was prevented. Furthermore, a decrease in the running cost was realized.
In accordance with the present invention, a deformation of the coil by its own weight during the heat treatment can be prevented by using a heat resistant metal, whereon an oxide film is formed, as an insulator for an oxide superconducting coil manufactured by a W & R method. Furthermore, by arranging silver or a silver alloy at an intermediate layer between the oxide superconducting wire material and a co-winding heat resistant alloy, a problem of reaction during the heat treatment can be solved. The above members have a sufficient mechanical strength against an electromagnetic force under a strong magnetic field, and accordingly, a magnet applicable to use in a strong magnetic field using the oxide superconducting coil can be realized. | A method for manufacturing an oxide superconducting coil can suppress deterioration of superconducting characteristics caused by a strong electromagnetic force and deformation and a reaction during heat treatment. The oxide superconducting coil is manufactured by a wind-and-react (W&R) method using a metal sheathed oxide superconducting wire material and an insulator, wherein an oxide film formed on a surface of a heat resistant alloy during a heat treatment is used for insulating the coil, and the heat resistant alloy has a sufficient strength to prevent the deformation of the coil generated by the weight of the coil itself during the heat treatment and to endure a strong electromagnetic force. An oxide superconducting coil operable with a coolant, such as liquid nitrogen, liquid helium, and the like, or a refrigerator, can be realized. | 7 |
RELATED PATENT APPLICATION
[0001] This application is a divisional of U.S. patent application Ser. No. 10/093,199, filed Mar. 7, 2002, and entitled “NO x Reduction System for Diesel Engines, Using Hydrogen Selective Catalytic Reduction.”
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to emission reduction systems for diesel engines, and more particularly to nitrogen oxide reduction using a hydrogen-selective catalytic reduction catalyst.
BACKGROUND OF THE INVENTION
[0003] In an effort to reduce ambient levels of air pollution in the United States, the United States Environmental Protection Agency (EPA) has proposed a tightening of the emissions standards for heavy-duty diesel engines. This proposal includes measures for reducing the allowable sulfur content of diesel fuel. The proposal aims to lower emissions by about 95 percent, with nitrogen oxides (NO x ) and particulate matter (PM) emission standards of 0.2 and 0.01 gram per brake horsepower hour, respectively.
[0004] Existing aftertreatment technologies for achieving these goals include both PM reduction systems and NOx reduction systems. For PM reduction, existing technologies include a continuously regenerating trap (CRT®) and catalyzed traps. The term “CRT®” refers specifically to the particulate filter manufactured by Johnson Matthey of London, United Kingdom, described in U.S. Pat. No. 4,902,487. For NOx reduction, existing technologies include selective catalytic reduction (SCR) systems that use urea as the reductant, and NOx storage catalysts.
[0005] Various factors determine which aftertreatment technology is most suitable for diesel engine exhaust. One consideration is the effect of the sulfur content in the diesel fuel. Sulfur increases the regenerating temperature of a CRT, which adversely affects its performance. Sulfur is also a poison for NOx traps. Because of the negative effects of sulfur on aftertreatment performance, the EPA is recommending a diesel fuel sulfur cap of 15 ppm.
[0006] However, evidence implies that 15 ppm may still be too high for NOx traps to be effective. As a result, urea SCR systems may be a more effective method for adequate NOx reduction.
[0007] Despite their effectiveness, urea SCR systems are not without their shortcomings. Urea SCR is based on ammonia reduction, with urea being the reductant of choice for vehicular applications, due to the perception that a supply of ammonia on-board a vehicle would be unsafe. Ammonia is considered to be highly toxic, whereas urea is only mildly toxic. But the problem with urea SCR is that a separate supply of urea is required on-board. Not only does this requirement call for a separate storage tank, but the urea must be replenished periodically and there is no infrastructure to provide a nationwide supply. Also, the system required to introduce urea into the exhaust stream is complex. In sum, there are many issues affecting the practicality of using urea for SCR.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a block diagram of a first embodiment of the invention.
[0009] [0009]FIG. 2 is a block diagram of a second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The invention described herein is directed to an SCR system that does not require urea as the reductant. The system uses diesel fuel instead of urea, which eliminates the requirement for a second supply tank and the need for a urea supply infrastructure.
[0011] [0011]FIGS. 1 and 2 describe two different embodiments of the invention. Both use an oxidation unit 10 a and a hydrogen selective catalytic reduction (H-SCR) unit 10 b , but in different configurations. Both embodiments are used with diesel engines, which do not run rich. The oxidation unit 10 a acts as a hydrogen generator, and runs “offline” of the main exhaust gas stream so that it may operate in a rich fuel environment. The hydrogen from oxidation unit 10 a is fed to the H-SCR catalyst 10 b , which continuously converts NO x to N 2 and H 2 O. An optional water gas shift (WGS) catalyst 10 c may be interposed between the partial oxidation unit 10 a and the H-SCR catalyst 10 b , to generate additional hydrogen.
[0012] As explained below, diesel fuel is partially oxidized by oxidation unit 10 b to produce a combination of hydrogen (H 2 ) and carbon monoxide (CO), with traces of carbon dioxide (CO 2 ) and water (H 2 O) produced as by products. The hydrogen is then used by an H-SCR catalyst 10 b to convert the NO x in the exhaust stream into nitrogen. The H-SCR catalyst 10 b is selected specifically to use hydrogen to reduce exhaust-borne NO x emissions, and operates under net oxidizing conditions (lambda>1).
[0013] [0013]FIG. 1 illustrates one embodiment of an H-SCR (hydrogen SCR) system 10 in accordance with the invention. Partial oxidation unit 10 a receives a fraction of the diesel fuel, relative to the fuel flow to engine 12 , from tank 11 . Partial oxidation unit 10 a may be any type of catalyst or non-stoichiometric burner, suitable for partial oxidation of hydrocarbons. In general, partial oxidation unit 10 a operates by converting diesel fuel into a gas mixture containing hydrogen as one of its primary components. In the embodiment of FIG. 1, partial oxidation unit 10 a receives diesel fuel from an auxiliary fuel line 15 off the main fuel line 13 and air from an air input line 16 . An output line 17 delivers the gas mixture to the main exhaust line 14 .
[0014] Partial oxidation catalysts exist that can convert hydrocarbons with conversion efficiency greater than 90 percent and selectivity to hydrogen in excess of 90 percent. Certain catalysts have already been proven effective at converting natural gas to hydrogen, namely nickel-based and rhodium-based formulations. These include Ni/Al 2 O 3 , Ni/La/Al 2 O 3 , and Rh/Al 2 O 3 . Although nickel-based catalysts may produce carbon, they are less expensive than rhodium-based catalysts.
[0015] Catalytic partial oxidation is a high space velocity process (e.g., 500,000 per hour), with residence times typically in the range of 10 to 1000 microseconds. Thus, the catalysts do not need to be large to have high efficiency and selectivity. Partial oxidation catalysts operate under reducing gas conditions, and the lambda in the partial oxidizer may be about 0.3 to 0.6.
[0016] In the embodiment of FIG. 1, an optional WGS catalyst 10 c is interposed directly downstream of the partial oxidation unit 10 a and upstream of H-SCR catalyst 10 b . WGS catalyst 10 c uses carbon monoxide (CO) generated by the partial oxidation unit 10 a to form additional hydrogen. To enable this reaction, supplemental water may be added to the gas mixture entering WGS catalyst 10 c . An advantage of using WGS catalyst 10 c is that more hydrogen can be produced from the same amount of fuel. In other words, less fuel is needed to generate the same amount of hydrogen.
[0017] The gas mixture from WGS catalyst 10 c is injected into the main diesel exhaust line 14 , upstream of H-SCR catalyst 10 b . In embodiments not having WGS catalyst 10 c , the gas mixture from partial oxidation unit 10 a would be injected into the main exhaust line 14 at the same point. In all embodiments, H-SCR catalyst 10 b then uses the hydrogen in the gas mixture to convert NO x into nitrogen and water.
[0018] [0018]FIG. 2 illustrates a second embodiment of the invention, an H-SCR system 20 , whose partial oxidation unit 10 a is positioned on a branch line 22 off the main exhaust line. The partial oxidation unit 10 a receives a portion of the exhaust diverted from the exhaust line, as well as diesel fuel from an auxiliary fuel line 21 . Under net reducing conditions, diesel fuel is converted into hydrogen, carbon monoxide and traces of carbon dioxide and water. Like system 10 , system 20 may have an optional WGS catalyst 10 c downstream of the partial oxidation unit 10 a . The hydrogen-enhanced gas mixture flows back into the main exhaust line, via an output branch line 23 , upstream of an H-SCR catalyst 10 b , which uses the hydrogen to convert NO x into nitrogen and water.
[0019] For system 20 , effective partial oxidation is achieved by controlling the diesel injection rate. When no supplemental diesel fuel is being injected into the exhaust stream, such as when NO x emissions from engine 12 are low, the partial oxidation unit 10 a acts as a full oxidation catalyst, converting unburned hydrocarbons and carbon monoxide into water and carbon dioxide. With the partial oxidation unit 10 a located in a branch off the main exhaust gas stream, a portion of the exhaust flows through the partial oxidation catalyst. As a result, less diesel fuel is required to enrich the gas entering the partial oxidation catalyst. Also, the partial oxidation catalyst can be smaller. At the same time, sufficient hydrogen must be generated to obtain effective reduction of the NO x in the H-SCR catalyst 10 b . This design has the advantages that the heat required to activate the partial oxidation catalyst may be provided by the exhaust gas instead of by an external heat source, and it may be possible to use the heat generated by the partial oxidation reaction to accelerate heating of the H-SCR catalyst 10 b during cold-start operation.
[0020] For both system 10 and system 20 , the products of partial oxidizer 10 a are metered into the diesel exhaust gas, upstream of H-SCR catalyst 10 b . The amount of gas injected should ideally be proportional to the amount of NO x in the exhaust. A 1:1 molar ratio of H 2 :NO is expected for efficient conversion of NO to N 2 in accordance with Equation (1) below. However, NO 2 exists in the diesel exhaust simultaneously with NO, either from the combustion process (approximately 15 percent) or from oxidation in a passive particulate trap such as a CRT (approximately 40 percent). A 2:1 ratio of H 2 :NO 2 is expected for efficient conversion of NO 2 to N 2 in accordance with Equation (2) below.
2NO+2H 2 --->N 2 +2H 2 O Equation (1):
2NO 2 +4H 2 --->N 2 +4H 2 O Equation (2):
[0021] Results of experimentation with ruthenium-based H-SCR catalysts using Ru/MgO and Ru/Al 2 O 3 have been reported by Hornung, et al. in a paper entitled “On the mechanism of the selective catalytic reduction of NO to N 2 by H 2 over Ru/MgO and Ru/Al 2 O 3 catalysts”, in Topics in Catalysis, 2000, 11/12 (1-4), 263-70. The reports are of 100 percent selectivity to N 2 . Another possible candidate for H-SCR catalyst 10 b is a platinum titania-zirconia catalyst, Pt/TiO 2 —ZrO 2 .
[0022] Potential fuel penalties may be calculated based on the NO:NO 2 ratio in the exhaust. If a range of NO 2 content is considered from 15 to 100 percent, the fuel economy penalty is calculated to be in a range from two to four percent. To estimate a realistic fuel economy penalty, a worst case scenario was used with a system containing a passive PM trap, such as a CRT, which creates high levels of NO 2 . Based on a 60:40 NO:NO 2 exhaust gas mixture, and using Equations (1) and (2), approximately 1.4 moles of H 2 are required per mole of NO x . Assuming ideal conditions of 100 percent efficient partial oxidation, 100 percent selectivity to H 2 , and 100 percent NO x conversion efficiency of the H—SCR catalyst, it was calculated that fuel economy would be reduced by 2.5 percent.
[0023] An advantage of the invention is that the invention effectively reduces tailpipe oxides of nitrogen emissions without the need for a reductant other than diesel fuel. It continuously converts NO x to nitrogen, by first generating hydrogen from the diesel fuel and then using the hydrogen in a hydrogen-based SCR catalyst. The system does not require adjustment of the engine air/fuel ratio, of engine combustion, or of any other engine functionality.
[0024] Other Embodiments
[0025] Although the present invention has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims. | An emission control system for reducing NO x in the exhaust of a diesel engine. A partial oxidation system receives diesel fuel from the engine's fuel tank and partially oxidizes the diesel fuel into hydrogen. The hydrogen is then introduced into the main exhaust line and the hydrogen-enhanced exhaust is delivered to a hydrogen selective catalytic reduction unit, which uses the hydrogen to convert the NO x to nitrogen. | 8 |
[0001] The following invention relates to a launched aerial surveillance vehicle, more specifically to a grenade or under-slung grenade launcher (UGL) aerial surveillance vehicle, a surveillance system and methods of providing rapid aerial surveillance.
[0002] UGLs are devices which are located underneath conventional guns, to launch a grenade. The grenade may contain high explosive payloads, smoke or other obscurants.
[0003] US2010/0057285 and EP0800052 are directed to mortar and artillery launched surveillance systems, respectively. Artillery and mortar launched systems are typically large calibre systems, typically of the order of at least 80 mm diameter, which require significant deployment systems such as a barrel or mortar tube and typically at least two operatives to deploy the round.
[0004] Before the present invention is described in further detail, it is to be understood that the invention is not limited to the particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.
[0005] According to a first aspect of the invention there is provided a grenade launched aerial surveillance vehicle, comprising
[0006] an integral propellant charge, whereupon launch said vehicle is launched from a grenade weapon,
[0007] wherein said surveillance vehicle comprises
[0008] a deployable wing
[0009] a guidance system comprising altitude lock to provide a substantially circular flight path around a target at a fixed GPS co-ordinate,
[0010] a means of providing directional nudge to the flight path,
[0011] an electrical power source,
[0012] at least one optical sensor, pivotally mounted on said vehicle,
[0013] communication device to relay guidance and data output from said at least one optical sensor to at least one remote user,
[0014] propulsion device for providing aerial movement of the vehicle,
[0015] a means for reducing the imparted spin on the vehicle prior to deployment of the surveillance vehicle located therein.
[0016] The grenade launcher may be a UGL on an infantry support weapon, mounted on a vehicle, vessel or craft, or a may form a single shot hand deployed grenade, similar to distress flare arrangement.
[0017] The use of a UGL launched round allows a vehicle which is encompassed in a fully integrated single munition, which is not reliant on specialist artillery equipment in order to launch the vehicle.
[0018] The vehicle according to the invention provides real-time, tactically significant and responsive visual surveillance information to Section/Platoon commanders over typical engagement ranges of 400-600 m, for several minutes duration. The vehicle is immediately deployable by the troops in the engagement area, without need for setting up a mortar tube or arranging for an artillery section to cease operations and provide a surveillance vehicle as described in the prior art.
[0019] The use of a mortar or artillery weapon during active combat is a valuable tool, and stopping a salvo of rounds to introduce a surveillance round to active theatre may afford loss of tactical advantage. However, a grenade launched vehicle, only requires one operative, who can deploy a round within a few seconds, rather than minutes for an artillery or mortar deployment. Typically the UGL is an add-on to a weapon, rather than the primary function, i.e. an assault weapon, and so the primary function is not compromised.
[0020] The ability to rapidly deploy the vehicle according to the invention thereby provides timely information without the requirement for tasking high-level reconnaissance assets. This aerial visual data aimed to provide information regarding potential enemy assets and equipment concealed out of line-of-sight, for example, within walled compounds.
[0021] Integral propellant charges are routine in grenade launched systems, this avoids the requirement of using a separate propellant charge and projectile, thereby reducing the burden of carrying a surveillance vehicle and separate charge.
[0022] Mortars and artillery rounds are subject to high pressures during launch, and are designed to launch projectiles with payloads in the order of kilograms. Therefore the casings of such projectiles are made from thick sections of metal, which add further mass to the system. Therefore a surveillance vehicle launched from such a system, encounters a significant weight penalty, and as such the vehicle portion will typically be housed in a launch canister, such that the vehicle inside needs to be deployed from the launch canister.
[0023] The grenade launched system uses much lower pressure systems, has a much lower mass per round, and hence the vehicle itself is launched without requirement of a launch canister or housing, to protect said vehicle from the launch pressures.
[0024] The at least one optical sensor may be selected from an IR camera, video camera, single shot camera, preferably a video camera. The optical sensor may be gyroscopically stabilised, specifically the stabilisation may compensate for roll attitude, preferably the optical sensor is a gyroscopically stabilised video camera.
[0025] The deployable wing may be selected from any collapsible wing, such as a parachute, parasail, parawing, inflatable wing. In a highly preferred arrangement the deployable wing is a parawing.
[0026] The parawing allows for a deployable wing that fits into a grenade sized projectile, and providing the stability and control constraints required for the vehicle. A parawing is steerable unlike typical parachutes and thus the parawing which can be packaged into such a small volume, unlike a fixed wing, provides aerodynamic efficiency, stability, control and overall design simplicity.
[0027] The parawing may be mounted at a fixed point on a trunion, which is pivotal about the vehicle casing, such that the trunion, pivots from a stowed position within the body of the vehicle to a deployed position which is exterior to the body of the vehicle. This allows the parawing to be affixed at a point exterior to the vehicle, which allows the ties of the parawing to be free from entanglement from internal components when in the deployed state.
[0028] A parawing is an inflatable wing that is pressurised by the dynamic pressure of the air in which it is operating and which is given span wise stiffness by means of an appropriately designed suspension harness that utilises the payload mass to provide both support and stiffness to the shape of the wing. A parawing is not an advanced form of parachute, it is a collapsible wing that has a high level of aerodynamic performance and a high level of natural stability and controllability. High performance parawings are able to achieve glide ratios in excess of 14:1, they have inherent natural stability which results from the fact that the heavy payload is suspended below the wing on thin but strong lines. The design of the support lines means that the wing/payload has inherent natural pendular stability and with correct layout of the rigging lines support and shaping of the wing is maintained during flight. The parawing has natural pendular stability and requires no additional aerodynamic surfaces to achieve stability
[0029] The means of providing directional nudge to the flight path, such as for example, left, right, up, down, forwards, backwards, may be effected by nudging the wing of the device to a new circular path, this may be achieved by means of moveable rigging (brake) lines that can be operated to adjust the camber of the wing in either an asymmetric manner to effect a turn or in a symmetric manner to adjust angle of attack and hence flight speed.
[0030] Parawings may be self-deploying, requiring very little effort to inflate them to a stable configuration and once in flight can be designed such that partial collapse of the canopy due to overzealous piloting or gusts correct themselves automatically—thereby providing a degree of gust alleviation to the concept. A drogue chute may optionally be used to assist in deployment.
[0031] The propulsion device for providing aerial movement of the vehicle may be provided by known propulsion means, electric motors, IC motors, pyrotechnic rocket motors, chemical gas generators, compressed gas, more preferably electric motors, such as for example, remote control airplane, motors, preferably provided with foldable propellers.
[0032] The guidance system comprising altitude lock to provide a substantially circular flight path around a target at a fixed GPS co-ordinate. The deployed vehicle may follow a circular path around a general area of interest, in a preferred arrangement and to ensure that the image of the target is enhanced and more closely observed the vehicle may preferably be directed to follow a pivotal altitude about the target at a fixed GPS co-ordinate. The pivotal altitude is the altitude at which for a given flight speed and constant turn radius that the lateral axis of the air vehicle points at the centre of rotation point on the ground regardless of the turn radius.
[0033] The guidance may be incorporated into a section or platoon commander's control device. The control device may comprise separate viewing and controls, such, as for example viewing may be achieved by a head up display or hand display. The control may be provide by separate control means, preferably control and visual display may be provided on a game pad type or touch screen tablets. The controls may provide the input to the nudge guidance system, there may be further focussing or image capture (stills shot) functionality provided on the control device. The imagery data from the proposed vehicle may be subjected to image processing performed using existing video stabilisation software. The software is preferably installed and run on the operator's hand-held viewing device, rather than on board the vehicle, to reduce power requirements on the vehicle.
[0034] The communication device is located on the vehicle to relay guidance and data output from said at least one optical sensor to a remote user. The communication device may be any wireless communication such as for example, radio, wifi, optical to enable data transfer to the device. The data may be encrypted or unencrypted.
[0035] Grenade launchers typically rely on spin stabilisation to provide increased accuracy during launch. The vehicle according to the invention is required to be substantially free from roll or spin during wing deployment and subsequent flight operation. It is therefore desirable that the means for reducing the imparted spin be able to remove the spin within a short period of time. Such means are well known to those in the art, such as, for example slipping obturators or deployable fins, preferably the vehicle comprises at least two deployable fins, which deploy shortly after leaving the launch platform. The at least two fins provide stability of the vehicle during the powered flight stage of the surveillance.
[0036] The vehicle when launched may be deployed at several metres per second. It may be desirable for a drogue chute to be deployed to slow down the vehicle and additionally assist deployment of the deployable wing. The vehicle may need to be slowed to allow the pivotal attitude to be set up about a target position. The deployment of a drogue chute may be determined by a timer delay, remote operative deployment, peak altitude, or automated deployment based on trajectory, velocity and GPS position to determine the optimum point of deployment, preferably the GPS position is used to determine the optimum point of deployment.
[0037] In a preferred arrangement the vehicle comprises at least one self-destruct mechanism; to disable and render inoperable the electronic components, remove any cached data. The self-destruct may be caused via known means such as the use of a pyrotechnic charge to cause a fire to destroy the components, or a high electrical current may be passed through the components, such energy may be applied via a fast switching capacitor.
[0038] According to a further aspect of the invention there is provided a method for providing aerial surveillance of a target area, providing the steps of:
[0039] launching at least one vehicle as defined herein in the direction of the target area to be surveyed,
[0040] determining a target and causing a first pivotal altitude to be maintained about said target at a first fixed GPS co-ordinate,
[0041] monitoring the data from the at least one optical sensor,
[0042] nudging the wing to set up a second pivotal altitude about a second target at a second fixed GPS co-ordinate,
[0043] monitoring the data from the at least one optical sensor,
[0044] optionally providing further nudges to provide further pivotal altitudes about a further target at a further fixed GPS co-ordinate, to provide a survey of the target area.
[0045] In a highly preferred arrangement the steps of launch, monitoring data and nudging the wing are undertaken by one operator. There may be more than one remote user, typically the images may be fed to multiple users so as to provide data to a number of operatives, i.e. those in active theatre and those at a command base who may be recording the data.
[0046] According to a further aspect of the invention there is provided a data surveillance system comprising a grenade launcher, at least one grenade launched aerial surveillance vehicle, and a control device. Preferably the control device may be capable of post processing the data from the optical sensor, such that there is image stabilisation applied to the data.
[0047] The nudge feature may be provided autonomously or by manual input from the operator. The use of autonomous steering, i.e. allowing the vehicle to plot and follow its own course according to a predetermined area to be surveyed will allow the operative to remain focussed on analysing the images without trying to control the vehicle.
[0048] Alternatively there may be more than one operative, such as, for example there may be a first operative proximate to the target who launches at least one grenade launched aerial surveillance vehicle and a second operative at a remote location who undertakes a survey of the area.
DETAILED DESCRIPTION
[0049] After launch and deployment of the stabilising fins the vehicle will transit via a ballistic trajectory to the point at which it transitions in various stages to its surveillance configuration. The proposed wrap-around fins will damp out the spin of the vehicle within one or two seconds and will provide sufficient directional stability to replace the gyroscopic stabilisation that would have been imparted by the spin rate. In order to provide sufficient directional stability via the proposed fins it will be essential to ensure that the centre of gravity of the components are well forward enough in the vehicle to provide sufficient static margin.
[0050] Upon initiation of the transition to surveillance mode a number of key events take place, such as for example deploy the parawing, uncover the camera lens, deploy the folding propellers and place the platform in a stable circular orbit. This may be controlled by a simple timer, initiated at launch, to signal the deployment sequence. Upon initiation of the sequence a mechanism, which may be driven by a small pyrotechnic charge, may unlatch the cylindrical outer casing of the vehicle and drive it rearwards by a distance of approximately 50 mm. At the same time this action will release the drop-out panels covering the bays containing the folding propeller blades and the folded parawing. It is anticipated that these panels will be jettisoned immediately after they are released from the vehicle body. Once the panels have been ejected the folding propellers and parawing will be deployed, typically by a simple integrated spring mechanism. The vehicle when it approaches its target may possibly still be travelling quite fast (up to 40 m/s) and that it may not be in an upright orientation. It may be convenient to employ a two-stage parawing deployment process. The first step may be the initial deployment of a very small drogue parachute to place the vehicle in a steady descent with an upright attitude, which should take in the order of a few seconds. Once this condition has been reached a second phase of deployment is initiated whereby the drogue parachute is used to deploy the parawing.
[0051] By virtue of the fact that the outer casing of the vehicle moved rearwards for parawing deployment it has also been designed so that this action also exposes the camera in its gimballed mounting. Thus, the proposed moving outer casing and ejectable panels provide a means of achieving a robust, hermetically sealed protection for all the internal components, during storage, ground handling and launch.
[0052] Retention of the stabilising fins during the parawing flight phase has significant benefit for stability of the camera platform. The rearward movement of the outer casing also has the effect of moving the stabilising fins further rearward and provides an even greater degree of stability of the camera platform suspended below the parawing.
[0053] The flying platform may operate at its pivotal altitude, the altitude at which for a given flight speed and constant turn radius the lateral axis of the aircraft points at the location on the ground about which the turn is centred. For a given flight speed there is a single altitude (the pivotal altitude) at which the lateral axis of the aircraft points directly at the centre of rotation point on the ground regardless of the radius of the turn. Aircraft pilots use this flying technique to carry out coordinated turns with respect to a fixed point on the ground.
[0054] The vehicle flight control system must maintain constant speed and altitude, a fixed camera angle within the airframe directed at the pre-defined centre-point of ground rotation results in an image that would rotate at the rotation speed of the vehicle's orbit around a fixed point in the centre of the image. This image would be useful to the operator providing it was not rotating too fast or preferably with the use of image processing software, be artificially made to appear quasi-stationary on the operators display.
[0055] If the flying platform was operating in a steady crosswind at a pivotal altitude and at constant speed and bank angle it would result in the orbit of the platform drifting with the prevailing wind, making continuous orbit about a fixed ground point difficult. The adoption of a variable bank angle technique is used by aircraft pilots in such circumstances when they wish to fly an orbit around a fixed ground point in such circumstances. As the aircraft flies in a circular orbit the pilot continuously adjusts the aircraft bank angle during the turn such that it is a minimum on the “into-wind” leg and at a maximum on the “down-wind” leg. Therefore the bank angle of the vehicle according to the invention would vary during the turn the camera requires a variable ‘axis of look’ preferably controlled by a heading lock gyroscope.
[0056] Once the parawing and folding propeller deployment phase has been completed the platform will be automatically programmed to enter a predetermined circling flight loiter mode, at a predefined altitude above ground with the camera actively pointed at the location on the ground about which the platform is circling. A simple on-board flight controller, based on simplified versions of current micro autopilot technology would provide appropriate station keeping with respect to a fixed ground location. The roll stabilised camera looking sideways and downwards from the vehicle may provide imagery for transmission back to the user. Changes in platform bank angle required to operate in windy conditions and due to sway of the platform due to gusts would be expected to be largely eliminated through gyroscopic stabilisation of the camera about the vehicle's roll axis.
[0057] The connection between the parawing and the camera may help to decouple the motions of the two components. The vehicle (and hence camera) are suspended from the parawing by a pivotal trunion mounting which is able to pivot about the pitch axis of the vehicle. This rigid trunion frame pivots about the centre of gravity of the vehicle (and camera) and enables an almost complete decoupling of the relative motions of the camera and the parawing about the pitch axis. Roll and yaw coupling between the parawing and the camera (vehicle) are minimised through the use of what are effectively “pin joints” where the parawing suspension lines attach to the top of the trunion frame. The effective “pin joints” decouple the motions of the parawing from the camera (vehicle), whereas stability of the camera (vehicle) in pitch and yaw is provided by means of its stabilising fins.
[0058] An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings of which:
[0059] FIG. 1 shows a vehicle in a deployed state
[0060] FIGS. 2 a to 2 d show the deployment sequence of the components, after launch
[0061] FIG. 3 shows a section through the vehicle in its launch configuration.
[0062] FIG. 4 shows an area to be surveyed, and a surveillance pattern.
[0063] Turning to FIG. 1 , shows a surveillance device 1 , with a vehicle 3 suspended from a parawing 2 , via control lines 4 . The vehicle 3 comprises a propeller 7 to provide forward flight, in the direction of the arrow. The vehicle 3 comprises a pivotal trunion 7 , which in its deployed position as shown, is exterior to the outer surface of the vehicle casing 3 , the control lines 4 are attached to the trunion, and are held free from the internal components (not shown) of the vehicle 3 . The vehicle 3 , is stabilised during flight by deployable fins 6 . The vehicle 3 is designed to be fired from a UGL launcher not shown.
[0064] FIGS. 2 a - d show a sequence of deployment from the launch configuration FIG. 2 a , through to a deployed configuration 2 d. In the launch configuration The vehicle 13 forms the body of the device 11 that is fired from the grenade launcher, there are no additional housings or containers which house the vehicle 13 . The launch propulsion is provided by a standard grenade launcher propellant cartridge 19 , which during storage forms an integral part of the vehicle 13 . During deployment the propellant cartridge 19 is fired by a launcher (not shown) which ejects the vehicle 13 , as it would with a typical high explosive payload.
[0000] Most grenade launchers rely on spin stabilisation to control the accuracy of the round, however, the device 11 needs to have the imparted spin removed very quickly, otherwise deployment of the parawing will be unduly delayed. Deployable fins 16 a, in their launch configuration, are biased such that upon launch they move radially outwards into a deployed state 16 . The fins 16 counteract the spinning moment on the vehicle 13 .
[0065] At a selected time the panels 12 and 14 are ejected from the body 13 , such as for example by shearing retaining pins, to allow the propeller to be deployed from a folded state 15 a to the final deployed state 15 . Similarly the pivotal trunion 17 is then able to move to its deployed state. The deployment of the propeller 15 and trunion 17 may be effected by the use of biased components such that when the sacrificial panels 12 , 14 are removed the propeller 15 and trunion 17 are urged into the deployed state. The parawing has been removed from clarity.
[0066] FIG. 3 shows a section of the device 21 , with the components in their launch configuration. The vehicle 21 , comprises a propellant cartridge 23 at the rear end. At the fore end, there is a propeller 24 in a folded state. The propeller 25 is powered by an electric motor 24 , which received the electrical energy from battery 29 . The battery 29 , also provide electrical energy to power the video camera 28 , the control servos 27 , which control and steer the parawing 22 when in the deployed state. The control servos are themselves activated by instructions from the autopilot system 26 , which may be based on a GPS based technology.
[0067] FIG. 4 shows an area of interest 35 to be surveyed. The vehicle 33 is made to obtain a pivotal altitude 31 b such that the camera (not shown) can provide surveillance of the area 32 b. the parawing may be steered to nudge the vehicle to a new pivotal altitude, such that a new surveillance area 32 a may be surveyed. A series of pivotal altitudes may be set up during the flight, to provide a complete picture of the total area of interest 35 . At the end of the flight the vehicle is bought down and destroyed 36 , preferably remote to the area of interest 35 . | The invention relates to a launched aerial surveillance vehicle, more specifically to a grenade or under-slung grenade launcher (UGL) aerial surveillance vehicle, a surveillance system and methods of providing rapid aerial surveillance.
The vehicle once deployed is capable of autonomous flight paths, with basic inputs to change the circular flight paths, so as to build up surveillance for an area of interest. The vehicle comprises at least on optical sensor, which may be IR or visible range, to survey the area of interest, and feed the images back to at least one remote user. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of copending application Ser. No. 426,058 filed Dec. 19, 1973 which was a division of then copending application Ser. No. 252,030, filed May 10, 1972.
BACKGROUND OF THE INVENTION
This invention relates to novel compositions of matter, to novel methods for producing those, and to novel chemical intermediates useful in those processes. Particularly, this invention relates to certain novel analogs of some of the known prostaglandins in which there is a phenoxy or substituted-phenoxy substituent at the C-16 position, i.e. on the carbon atom adjacent to the hydroxy-substituted carbon in the methyl-terminated chain.
The known prostaglandins include, for example, prostaglandin E 2 (PGE 2 ), prostaglandin F 2 alpha and beta (PGF 2 α amd PGF 2 β), prostaglandin A 2 (PGA 2 ), prostaglandin B 2 (PGB 2 ), and the corresponding PG 1 compounds. Each of the above-mentioned known prostaglandins is a derivative of prostanoic acid which has the following structure and atom numbering: ##STR1## See, for example, Bergstrom et al., Pharmacol. Rev. 20, 1 (1968), and references cited therein. A systematic name for prostanoic acid is 7-[(2β-octyl)-cyclopent-1α-yl]-heptanoic acid.
PGE 2 has the following structure: ##STR2## PGF 2 α has the following structure: ##STR3## PGF 2 β has the following structure: ##STR4## PGA 2 has the following structure: ##STR5## PGB 2 has the following structure: ##STR6##
Each of the known PG 1 prostaglandins, PGE 1 , PGF 1 α, PGF 1 β, PGA 1 , and PGB 1 , has a structure the same as that shown for the corresponding PG 2 compound except that, in each, the cis carbon-carbon double bond between C-5 and C-6 is replaced by a single bond. For example, PGE 1 has the following structure: ##STR7## In formulas II to VII, as well as in the formulas given hereinafter, broken line attachments to the cyclopentane ring indicate substituents in alpha configuration, i.e., below the plane of the cyclopentane ring. Heavy solid line attachments to the cyclopentane ring indicate substituents in beta configuration, i.e., above the plane of the cyclopentane ring.
Following the conventional numbering of the carbon atoms in the prostanoic acid structure, C-16 designates the carbon atom adjacent to the hydroxy-substituted carbon atom (C-15).
The side-chain hydroxy at C-15 in formulas II to VII is in S configuration. See, Nature, 212, 38 (1966) for discussion of the stereochemistry of the prostaglandins.
Molecules of the known prostaglandins each have several centers of asymmetry, and can exist in racemic (optically inactive) form and in either of the two enantiomeric (optically active) forms, i.e. the dextrorotatory and levorotatory forms. As drawn, formulas II to VII each represent the particular optically active form of the prostaglandin which is obtained from certain mammalian tissues, for example, sheep vesicular glands, swine lung, or human seminal plasma, or by carbonyl and/or double bond reduction of that prostaglandin. See, for example, Bergstrom et al., cited above. The mirror image of each of formulas II to VII represents the other enantiomer of that prostaglandin. The racemic form of a prostaglandin contains equal numbers of both enantiomeric molecules, and one of formulas II to VII and the mirror image of that formula is needed to represent correctly the corresponding racemic prostaglandin. For convenience hereinafter, use of the terms PGE 1 , PGE 2 , PGE 3 , PGF 1 α, and the like, will mean the optically active form of that prostaglandin with the same absolute configuration as PGE 1 obtained from mammalian tissues. When reference to the racemic form of one of those prostaglandins is intended, the word "racemic" or "dl" will precede the prostaglandin name, thus, racemic PGE 1 or dl-PGF 2 α.
PGE 1 , PGE 2 , and the corresponding PGF.sub.α, PGF.sub.β, PGA, and PGB compounds, and their esters, acylates, and pharmacologically acceptable salts, are extremely potent in causing various biological responses. For that reason, these compounds are useful for pharmacological purposes. See, for example, Bergstrom et al., cited above. A few of those biological responses are systemic arterial blood pressure lowering in the case of the PGF.sub.β and PGA compounds as measured, for example, in anesthetized (pentobarbital sodium) pentolinium-treated rats with indwelling aortic and right heart cannulas; pressor activity, similarly measured for the PGF.sub.α compounds; stimulation of smooth muscle as shown, for example, by tests on strips of guinea pig ileum, rabbit duodenum, or gerbil colon; potentiation of other smooth muscle stimulants; antilipolytic activity as shown by antagonism of epinephrine-induced mobilization of free fatty acids or inhibition of the spontaneous release of glycerol from isolated rat fat pads; inhibition of gastric secretion in the case of the PGE and PGA compounds as shown in dogs with secretion stimulated by food or histamine infusion; activity on the central nervous system; controlling spasm and facilitating breathing in asthmatic conditions; decrease of blood platelet adhesiveness as shown by platelet-to-glass adhesiveness, and inhibition of blood platelet aggregation and thrombus formation induced by various physical stimuli, e.g., arterial injury, and various biochemical stimuli, e.g., ADP, ATP, serotonin, thrombin, and collagen; and in the case of the PGE and PGB compounds, stimulation of epidermal proliferation and keratinization as shown when applied in culture to embryonic chick and rat skin segments.
Because of these biological responses, these known prostaglandins are useful to study, prevent, control, or alleviate a wide variety of diseases and undesirable physiological conditions in birds and mammals, including humans, useful domestic animals, pets, and zoological specimens, and in laboratory animals, for example, mice, rats, rabbits, and monkeys.
For example, these compounds, and especially the PGE compounds, are useful in mammals, including man, as nasal decongestants. For this purpose, the compounds are used in a dose range of about 10 μg. to about 10 mg. per ml. of a pharmacologically suitable liquid vehicle or as an aerosol spray, both for topical application.
The PGE, PGF.sub.α, and PGA compounds are useful in the treatment of asthma. For example, these compounds are useful as bronchodilators or as inhibitors of mediators, such as SRS-A, and histamine which are released from cells activated by an antigen-antibody complex. Thus, these compounds control spasm and facilitate breathing in conditions such as bronchial asthma, bronchitis, bronchiectasis, pneumonia and emphysema. For these purposes, these compounds are administered in a variety of dosage forms, e.g., orally in the form of tablets, capsules, or liquids; rectally in the form of suppositories; parenterally, subcutaneously, or intramuscularly, with intravenous administration being preferred in emergency situations; by inhalation in the form of aerosols or solutions for nebulizers; or by insufflation in the form of powder. Doses in the range of about 0.01 to 5 mg. per kg. of body weight are used 1 to 4 times a day, the exact dosage depending on the age, weight, and condition of the patient and on the frequency and route of administration. For the above use these prostaglandins can be combined advantageously with other anti-asthmatic agents, such as sympathomimetic (isoproterenol, phenylephrine, ephedrine, etc); xanthine derivatives (theophylline and aminophyllin); and corticosteroids (ACTH and predinisolone). Regarding use of these compounds see South African Pat. No. 68/1055.
The PGE and PGA compounds are useful in mammals, including man and certain useful animals, e.g., dogs and pigs, to reduce and control excessive gastric secretion, thereby reducing or avoiding gastrointestinal ulcer formation, and accelerating the healing of such ulcers already present in the gastrointestinal tract. For this purpose, the compounds are injected or infused intravenously, subcutaneously, or intramuscularly in an infusion dose range about 0.1 μg. to about 500 μg. per kg. of body weight per minute, or in a total daily dose by injection or infusion in the range about 0.1 to about 20 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful whenever it is desired to inhibit platelet aggregation, to reduce the adhesive character of platelets, and to remove or prevent the formation of thrombi in mammals, including man, rabbits, and rats. For example, these compounds are useful in the treatment and prevention of myocardial infarcts, to treat and prevent post-operative thrombosis, to promote patency of vascular grafts following surgery, and to treat conditions such as atherosclerosis, arteriosclerosis, blood clotting defects due to lipemia, and other clinical conditions in which the underlying etiology is associated with lipid imbalance or hyperlipidemia. For these purposes, these compounds are administered systemically, e.g., intravenously, subcutaneously, intramuscularly, and in the form of sterile implants for prolonged action. For rapid response, especially in emergency situation, the intravenous route of administration is preferred. Doses in the range about 0.005 to about 20 mg. per kg. of body weight per day are used, the exact dose depending on the age, weight, and condition of the patient or animal, and on the frequency and route of administration.
The PGE, PGF.sub.α, and PGF.sub.β compounds are especially useful as additives to blood, blood products, blood substitutes, and other fluids which are used in artifical extracorporeal circulation and perfusion of isolated body portions, e.g., limbs and organs, whether attached to the original body, detached and being preserved or prepared for transplant, or attached to the new body. During these circulations and perfusions, aggregated platelets tend to block the blood vessels and portions of the circulation apparatus. This blocking is avoided by the presence of these compounds. For this purpose, the compound is added gradually or in single or multiple portions to the circulating blood, to the blood of the donor animal, to the perfused body portion, attached or detached, to the recipient, or to two or all of those at a total steady state dose of about 0.001 to 10 mg. per liter of circulating fluid. It is especially useful to use these compounds in laboratory animals, e.g., cats, dogs, rabbits, monkeys, and rats, for these purposes in order to develop new methods and techniques for organ and limb transplants.
PGE compounds are extremely potent in causing stimulation of smooth muscle, and are also highly active in potentiating other known smooth muscle stimulators, for example, oxytocic agents, e.g., oxytocin, and the various ergot alkaloids including derivatives and analogs thereof. Therefore, PGE 2 , for example, is useful in place of or in combination with less than usual amounts of these known smooth muscle stimulators, for example, to relieve the symptoms of paralytic ileus, or to control or prevent atonic uterine bleeding after abortion or delivery, to aid in expulsion of the placenta, and during the puerperium. For the latter purpose, the PGE compound is administered by intravenous infusion immediately after abortion or delivery at a dose in the range about 0.01 to about 50 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, subcutaneous, or intramuscular injection or infusion during puerperium in the range 0.01 to 2 mg. per kg. of body weight per day, the exact dose depending on the age, weight, and condition of the patient or animal.
The PGA and PGF.sub.β compounds are useful as hypotensive agents to reduce blood pressure in mammals, including man. For this purpose, the compounds are administered by intravenous infusion at the rate of about 0.01 to about 50 μg. per kg. of body weight per minute, or in single or multiple doses of about 25 to 500 μg. per kg. of body weight total per day.
The PGA compounds and derivatives and salts thereof increase the flow of blood in the mammalian kidney, thereby increasing volume and electrolyte content of the urine. For that reason, PGA compounds are useful in managing cases of renal disfunction, especially in cases of severely impaired renal blood flow, for example, the hepatorenal syndrome and early kidney transplant rejection. In cases of excessive or inappropriate ADH (antidiuretic hormone; vasopressin) secretion, the diuretic effect of these compounds is even greater. In anephretic states, the vasopressin action of these compounds is especially useful. Illustratively, the PGA compounds are useful to alleviate and correct cases of edema resulting, for example, from massive surface burns, and in the management of shock. For these purposes, the PGA compounds are preferably first administered by intravenous injection at a dose in the range 10 to 1000 μg. per kg. of body weight or by intraveneous infusion at a dose in the range 0.1 to 20 μg. per kg. of body weight per minute until the desired effect is obtained. Subsequent doses are given by intravenous, intramuscular, or subcutaneous injection or infusion in the range 0.05 to 2 mg. per kg. of body weight per day.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful in place of oxytocin to induce labor in pregnant female animals, including man, cows, sheep, and pigs, at or near term, or in pregnant animals with intrauterine death of the fetus from about 20 weeks to term. For this purpose, the compound is infused intraveneously at a dose of 0.01 to 50 μg. per kg. of body weight per minute until or near the termination of the second stage of labor, i.e., expulsion of the fetus. These compounds are especially useful when the female is one or more weeks post-mature and natural labor has not started, or 12 to 60 hours after the membranes have ruptured and natural labor has not yet started. An alternative route of administration is oral.
The PGE, PGF.sub.α, and PGF.sub.β compounds are useful for controlling the reproductive cycle in ovulating female mammals, including humans and animals such as monkeys, rats, rabbits, dogs, cattle, and the like. By the term ovulating female mammals is meant animals which are mature enough to ovulate but not so old that regular ovulation has ceased. For that purpose, PGF 2 α, for example, is administered systemically at a dose level in the range 0.01 mg. to about 20 mg. per kg. of body weight of the female mammal, advantageously during a span of time starting approximately at the time of ovulation and ending approximately at the time of menses or just prior to menses. Intravaginal and intrauterine are alternative routes of administration. Additionally, expulsion of an embryo or a fetus is accomplished by similar administration of the compound during the first third of the normal mammalian gestation period.
As mentioned above, the PGE compounds are potent antagonists of epinephrine-induced mobilization of free fatty acids. For this reason, this compound is useful in experimental medicine for both in vitro and in vivo studies in mammals, including man, rabbits, and rats, intended to lead to the understanding, prevention, symptom alleviation, and cure of diseases involving abnormal lipid mobilization and high free fatty acid levels, e.g., diabetes mellitus, vascular diseases, and hyperthyroidism.
The PGE and PGB compounds promote and accelerate the growth of epidermal cells and keratin in animals, including humans, useful domestic animals, pets, zoological specimens, and laboratory animals. For that reason, these compounds are useful to promote and accelerte healing of skin which has been damaged, for example, by burns, wounds, and abrasions, and after surgery. These compounds are also useful to promote and accelerate adherence and growth of skin autografts, especially small, deep (Davis) grafts which are intended to cover skinless areas by subsequent outward growth rather than initially, and to retard rejection of homografts.
For these purposes, these compounds are preferably administered topically at or near the site where cell growth and keratin formation is desired, advantageously as an aerosol liquid or micronized powder spray, as an isotonic aqueous solution in the case of wet dressings, or as a lotion, cream, or ointment in combination with the usual pharmaceutically acceptable diluents. In some instances, for example, when there is substantial fluid loss as in the case of extensive burns or skin loss due to other causes, systemic administration is advantageous, for example, by intravenous injection or infusion, separate or in combination with the usual infusions of blood, plasma, or substitutes thereof. Alternative routes of administration are subcutaneous or intramuscular near the site, oral, sublingual, buccal, rectal, or vaginal. The exact dose depends on such factors as the route of administration, and the age, weight, and condition of the subject. To illustrate, a wet dressing for topical application to second and/or third degree burns of skin area 5 to 25 square centimeters would advantageously involve use of an isotonic aqueous solution containing 1 to 500 μg./ml. of the PGB compound or several times that concentration of the PGE compound. Especially for topical use, these prostaglandins are useful in combination with antibiotics, for example, gentamycin, neomycin, polymyxin B, bacitracin, spectinomycin, and oxytetracycline, with other antibacterials, for example, mafenide hydrochloride, sulfadiazine, furazolium chloride, and nitrofurazone, and with corticoid steroids, for example, hydrocortisone, prednisolone, methylprednisolone, and fluprednisolone, each of those being used in the combination at the usual concentration suitable for its use alone.
SUMMARY OF THE INVENTION
It is a purpose of this invention to provide novel 16-phenoxy and 16-(substituted phenoxy) prostaglandin analogs in which there is variable chain length in the side chains. It is a further purpose to provide esters, lower alkanoates, and pharmacologically acceptable salts of said analogs. It is a further purpose to provide novel processes for preparing said analogs and esters. It is still a further purpose to provide novel intermediates useful in said processes.
The presently described acids and esters of the 16-phenoxy and 16-(substituted phenoxy) prostaglandin analogs include compounds of the following formulas, and also the racemic compounds of each respective formula and the mirror image thereof: ##STR8##
In formulas VIII to XXII, g is an integer from 2 to 5, inclusive; M is ##STR9## R 1 is hydrogen or alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; R 2 and R 3 are hydrogen, methyl, or ethyl; T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoro, or --OR 4 wherein R 4 is alkyl of one to 3 carbon atoms, inclusive; and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl. R 2 and R 3 may be the same or different.
Formula IX represents 16-phenoxy-18,19,20-trinor-PGF 1 α when g is 3, M is ##STR10## R 1 and R 2 are hydrogen, R 3 is methyl, and s is zero. Formula XIII represents 16-(2,4-dichlorophenoxy)-16-methyl-2a,2b-dihomo-18,19,20-trinor-PGE 2 , methyl ester, when g is 5, M is ##STR11## R 1 , R 2 , and R 3 are methyl, T is chloro, and s is 2. Formula XX represents 16-(4-fluoro-2,5-xylyloxy)-2,19,20-trinor-15β-13,14-dihydro-PGF 1 β, dodecyl ester, when g is 2, M is ##STR12## R 1 is dodecyl, R 2 is hydrogen, R 3 is ethyl, T is fluoro and methyl, and s is 3.
In the name of the formula-IX example above, "18,19,20-trinor" indicates absence of three carbon atoms from the hydroxy-substituted side chain of the PGF 1 α structure. Following the atom numbering of the prostanoic acid structure, C-18, C-19, C-20 are construed as missing, and the methylene at C-17 is replaced with a terminal methyl group. Likewise, in the formula-XX example, "2,19,20-trinor" indicates the absence of the C-2 carbon atom from the carboxy-terminated side chain, and the C-19 and C-20 carbon atoms from the hydroxy-substituted side chain. In this system of nomenclature, the words "nor," "dinor," "trinor," "tetranor," or "pentanor" in the names of the prostaglandin analogs are to be construed as indicating one, two, three, four, or five carbon atoms, respectively, missing from the C-2 to C-4 and C-17 to C-20 positions of the prostanoic acid carbon skeleton.
In the name of the formula-XIII example, "2a,2b-dihomo" indicates two additional carbon atoms in the carboxy-terminated side chain specifically between the C-2 and C-3 carbon atoms. There are, therefore, nine carbon atoms in that side chain instead of the normal seven in the prostanoic acid structure. From the end of the chain to the double bond of the example they are identified as C-1, C-2, C-2a, C-2b, C-3, C-4, and C-5. The carbon atoms connected by the cis double bond are C-5 and C-6, and the carbon atoms between the double bond and the ring are C-6 and C-7.
As in the case of formulas II to VII, formulas VIII to XXII, wherein M is ##STR13## i.e. wherein the hydroxyl is attached to the side chain in alpha configuration, are each intended to represent optically active prostanoic acid derivatives with the same absolute configuration as PGE 1 obtained from mammalian tissues.
Also included within this invention are the 15-epimer compounds of formulas VIII to XXII wherein M is ##STR14## i.e. the C-15 hydroxyl is in beta configuration. Hereinafter "15β" refers to the epimeric configuration. Thus, "16-phenoxy-18,19,20-trinor-15β-PGF 1 α " identifies the 15-epimeric compound corresponding to the formula-IX example above except that it has the beta configuration at C-15 instead of the natural alpha configuration of 16-phenoxy-18,19,20-trinor-PGF 1 α.
Each of formulas VIII to XXII plus its mirror image describe a racemic compound within the scope of this invention. For convenience hereinafter, such a racemic compound is designated by the prefix "racemic" (or "dl") before its name; when that prefix is absent, the intent is to designate an optically active compound represented by the appropriate formula VIII to XXII.
With regard to formulas VIII to XXII, examples of alkyl of one to 12 carbon atoms, inclusive, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and isomeric forms thereof. Examples of cycloalkyl of 3 to 10 carbon atoms, inclusive, which includes alkyl-substituted cycloalkyl, are cyclopropyl, 2-methylcyclopropyl, 2,2-dimethylcyclopropyl, 2,3-diethylcyclopropyl, 2-butylcyclopropyl, cyclobutyl, 2-methylcyclobutyl, 3-propylcyclobutyl, 2,3,4-triethylcyclobutyl, cyclopentyl, 2,2-dimethylcyclopentyl, 2-pentylcyclopentyl, 3-tert-butylcyclopentyl, cyclohexyl, 4-tert-butylcyclohexyl, 3-isopropylcyclohexyl, 2,2-dimethylcyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl. Examples of aralkyl of 7 to 12 carbon atoms, inclusive, are benzyl, phenethyl, 1-phenylethyl, 2-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-(1-naphthylethyl), and 1-(2-naphthylmethyl). Examples of phenyl substituted by one to 3 chloro or alkyl of one to 4 carbon atoms, inclusive, are p-chlorophenyl, m-chlorophenyl, o-chlorophenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, p-tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-tertbutylphenyl, 2,5-dimethylphenyl, 4-chloro-2-methylphenyl, and 2,4-dichloro-3-methylphenyl.
Examples of ##STR15## as defined above are phenyl, (o--, m--, or p--)tolyl, (o--, m--, or p--)ethylphenyl, 2-ethyl-p-tolyl, 4-ethyl-o-tolyl, 5-ethyl-m-tolyl, (o--, m--, or p--)-propylphenyl, 2-propyl-(o--, m--, p--)tolyl, 4-isopropyl-2,6-xylyl, 3-propyl-4-ethylphenyl, (2,3,4-, 2,3,5-, 2,3,6-, or 2,4,5-)trimethylphenyl, (o--, m--, or p--)fluorophenyl, 2-fluoro-(o--, m--, or p--)tolyl, 4-fluoro-2,5-xylyl, (2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)difluorophenyl, (o--, m--, or p--)-chlorophenyl, 2-chloro-p-tolyl, (3-, 4-, 5-, or 6-)chloro-o-tolyl, 4-chloro-2-propylphenyl, 2-isopropyl-4-chlorophenyl, 4-chloro-3,5-xylyl, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenyl, 4-chloro-3-fluorophenyl, (3-, or 4-)chloro-2-fluorophenyl, α,α,α-trifluoro-(o--, m--, or p--)-tolyl, (o--, m--, or p--)methoxyphenyl, (o--, m--, or p--)ethoxyphenyl, (4- or 5-)chloro-2-methoxyphenyl, and 2,4-dichloro(5- or 6-)methoxyphenyl.
Accordingly, there is provided an optically active compound of the formula ##STR16## or a racemic compound of that formula and the mirror image thereof, wherein D is one of the four carbocyclic moieties: ##STR17## wherein ˜ indicates attachment of hydroxyl to the ring in alpha or beta configuration; wherein (a) X is trans--CH═CH--or --CH 2 CH 2 -, and Y is --CH 2 CH 2 --, or (b) X is trans--CH═CH--and Y is cis--CH═CH--; wherein g is an integer from 2 to 5, inclusive; wherein M is ##STR18## wherein R 1 is hydrogen or alkyl of one to 12 carbon atoms, inclusive, cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl substituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive; wherein R 2 and R 3 are hydrogen, methyl, or ethyl; wherein T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoro, or --OR 4 wherein R 4 is alkyl of one to 3 carbon atoms, inclusive, and wherein s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl; including the lower alkanoates thereof, and the pharmacologically acceptable salts thereof when R 1 is hydrogen.
Formula XXIII, which is written in generic form for convenience, represents PGE-type compounds when D is ##STR19## PGF.sub.α -type compounds when D is ##STR20## PGF.sub.β -type compounds when D is ##STR21## PGA-type compounds when D is ##STR22## and PGB-type compounds when D is ##STR23##
The novel formula VIII-to-XXIII compounds and the racemic compounds of this invention each cause the biological responses described above for the PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds, respectively, and each of these novel compounds is accordingly useful for the abovedescribed corresponding purposes, and is used for those purposes in the same manner as described above.
The known PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB compounds are all potent in causing multiple biological responses even at low doses. For example, PGE 1 and PGE 2 both cause vasodepression and smooth muscle stimulation at the same time they exert antilipolytic activity. Moreover, for many applications, these known prostaglandins have an inconveniently short duration of biological activity. In striking contrast, the novel prostaglandin analogs of formulas VIII to XXIII and their racemic compounds are substantially more specific with regard to potency in causing prostaglandin-like biological responses, and have a substantially longer duration of biological activity. Therefore, each of these novel prostaglandin analogs is surprisingly and unexpectedly more useful than one of the corresponding above-mentioned known prostaglandins for at least one of the pharmacological purposes indicated above for the latter, because it has a different and narrower spectrum of biological potency than the known prostaglandin, and therefore is more specific in its activity and causes smaller and fewer undesired side effects than when the known prostaglandin is used for the same purpose. Moreover, because of its prolonged activity, fewer and smaller doses of the novel prostaglandin analog can frequently be used to attain the desired result.
To obtain the optimum combination of biological response specificity, potency, and duration of activity, certain compounds within the scope of formulas VIII to XXIII are preferred. For example, it is preferred that the hydroxyl at C-15 be in the alpha configuration.
Another preference is that g be 3, i.e. that the carboxy-terminated side chain contain 7 carbon atoms.
Another preference is that subsitution on the phenoxy be in the para position, at least.
Still another preference is that R 2 and R 3 be hydrogen or methyl. Both can be hydrogen, both can be methyl, or one can be hydrogen and the other methyl. When only one is methyl, C-16 is an asymmetric carbon atom and two isomeric forms exist with respect to the stereochemistry at C-16. That isomer is preferred, for the purposes described herein, which has the greater desired biological activity when subjected to tests known in the art. For example, smooth muscle stimulation is indicated in smooth muscle strip tests (see J. R. Weeks et al., Journal of Applied Physiology 25, (No. 6), 783 (1968); and antisecretory activity is indicated in in vivo tests with laboratory animals (see A. Robert, "Antisecretory Property of Prostaglandins," Prostaglandin Symposium of the Worcester Foundation for Experimental Biology, Interscience, 1968, pp. 47-54).
Another advantage of the novel compounds of this invention, expecially the preferred compounds defined hereinabove, compared with the known prostaglandins, is that these novel compounds are administered effectively orally, sublingually, intravaginally, bucally, or rectally, in addition to usual intravenous, intramuscular, or subcutaneous injection or infusion methods indicated above for the uses of the known prostaglandins. These qualities are advantageous because they facilitate maintaining uniform levels of these compounds in the body with fewer, shorter, or smaller doses, and make possible self-administration by the patient.
The 16-phenoxy and 16-(substituted phenoxy) PGE, PGF.sub.α, PGF.sub.β, PGA, and PGB-type analogs encompassed by Formulas VIII to XXIII including their alkanoates, are used for the purposes described above in the free acid form, in ester form, or in pharmacologically acceptable salt form. When the ester form is used, the ester is any of those within the above definition of R 1 . However, it is preferred that the ester be alkyl of one to 12 carbon atoms, inclusive. Of those alkyl, methyl and ethyl are especially preferred for optimum absorption of the compound by the body or experimental animal system; and straight-chain octyl, nonyl, decyl, undecyl, and dodecyl are especially preferred for prolonged activity in the body or experimental animal.
Pharmacologically acceptable salts of these Formula VIII-to-XXIII compounds useful for the purposes described above are those with pharmacologically acceptable metal cations, ammonium, amine cations, or quaternary ammonium cations.
Especially preferred metal cations are those derived from the alkali metals, e.g., lithium, sodium and potassium, and from the alkaline earth metals, e.g., magnesium and calcium, although cationic forms of other metals, e.g., aluminum, zinc, and iron are within the scope of this invention.
Pharmacologically acceptable amine cations are those derived from primary, secondary, or tertiary amines. Examples of suitable amines are methylamine, dimethylamine, trimethylamine, ethylamine, dibutylamine, triisopropylamine, N-methylhexylamine, decylamine, dodecylamine, allylamine, crotylamine, cyclopentylamine, dicyclohexylamine, benzylamine, dibenzylamine, α-phenylethylamine, β-phenylethylamine, ethylenediamine, diethylenetriamine, and like aliphatic, cycloaliphatic, and araliphatic amines containing up to and including about 18 carbon atoms, as well as heterocyclic amines, e.g., piperidine, morpholine, pyrrolidine, piperazine, and lower-alkyl derivatives thereof, e.g., 1-methylpiperidine, 4-ethylmorpholine, 1-isopropylpyrrolidine, 2-methylpyrrolidine, 1,4-dimethylpiperazine, 2-methylpiperidine, and the like, as well as amines containing water-solubilizing or hydrophilic groups, e.g., mono-, di-, and triethanolamine, ethyldiethanolamine, N-butylethanolamine, 2-amino-1-butanol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl)aminomethane, N-phenylethanolamine, N-(p-tert-amylphenyl)diethanolamine, galactamine, N-methylglycamine, N-methylglucosamine, ephedrine, phenylephrine, epinephrine, procaine, and the like.
Examples of suitable pharmacologically acceptable quaternary ammonium cations are tetramethylammonium, tetraethylammonium, benzyltrimethylammonium, phenyltriethylammonium, and the like.
The compounds encompassed by Formulas VIII to XXIII are used for the purposes described above in free hydroxy form or also in the form wherein the hydroxy moieties are transformed to lower alkanoate moieties, e.g., --OH to --OCOCH 3 . Examples of lower alkanoate moieties are acetoxy, propionyloxy, butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, and branched chain alkanoyloxy isomers of those moieties. Especially preferred among these alkanoates for the above described purposes are the acetoxy compounds. These free hydroxy and alkanoyloxy compounds are used as free acids, as esters, and in salt form all as described above.
As discussed above, the compounds of Formulas VIII to XXIII are administered in various ways for various purposes; e.g., intravenously, intramuscularly, subcutaneously, orally, intravaginally, rectally, buccally, sublingually, topically, and in the form of sterile implants for prolonged action. For intravenous injection or infusion, sterile aqueous isotonic solutions are preferred. For that purpose, it is preferred because of increased water solubility that R 1 in the formula VIII-to-XXIII compound be hydrogen or a pharmacologically acceptable cation. For subcutaneous or intramuscular injection, sterile solutions or suspensions of the acid, salt, or ester form in aqueous or non-aqueous media are used. Tablets, capsules, and liquid preparations such as syrups, elixirs, and simple solutions, with the usual pharmaceutical carriers are used for oral sublingual administration. For rectal or vaginal administration, suppositories prepared as known in the art are used. For tissue implants, a sterile tablet or silicone rubber capsule or other object containing or impregnated with the substance is used.
The 16-phenoxy and 16-(substituted phenoxy) PGE-, PGF.sub.α -, PGF.sub.β -, PGA-, and PGB-type analogs encompassed by formulas VIII to XXIII are produced by the reactions and procedures described and exemplified hereinafter.
Reference to Charts A and B herein, will make clear the steps for preparing the formula-XXIV through XXXIV intermediates.
Previously, the preparation of an intermediate bicyclic lactone diol of the formula ##STR24## was reported by E. J. Corey et al., J. Am. Chem. Soc. 91, 5675 (1969), and later disclosed in an optically active ##STR25## form by E. J. Corey et al., J. Am. Chem. Soc. 92, 397 (1970). Conversion of this intermediate to PGE 2 and PGF 2 α, either in racematic or optically active form, was disclosed in those publications.
The iodolactone of formula XXIV in Chart A is known in the art (see Corey et al., above). It is available in either racemic or optically active (+ or -) form. For racemic products, the racemic form is used. For prostaglandins of natural configuration, the laevorotatory form (-) is used.
In Charts A and B, g, M, R 2 , R 3 , T, and s have the same meanings as defined above, namely: g is an integer from 2 to 5, inclusive; M is ##STR26## R 2 and R 3 are hydrogen, methyl, or ethyl, T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoromethyl, or OR 4 wherein R 4 is alkyl of one to 3 carbon atoms, inclusive, and s is zero, one, 2 or 3, with the proviso that not more than two T's are other than alkyl. In addition, M' is ##STR27## THP is tetrahydropyranyl; Q is ##STR28## wherein R 2 , R 3 , T, and s are as defined above; and ˜ represents attachment of hydroxy in alpha or beta configuration.
The formula-XXV compound (Chart A) bears an R 5 O-- moiety at the 4-position, wherein R 5 is (1) ##STR29## wherein G is alkyl of one to 3 carbon atoms, inclusive, phenylalkyl of 7 to 10 carbon atoms, inclusive, or nitro, and j is zero to 5, inclusive, provided that not more than two G's are other than alkyl, and that the total number of carbon atoms in the G's does not exceed 10 carbon atoms; (2) ##STR30## wherein R 6 is alkyl of one to 4 carbon atoms, inclusive; (3) ##STR31## wherein G and j are as defined above; or (4) acetyl. In preparing the formula-XXV compound by replacing the hydrogen of the hydroxyl group in the 4-position with the acyl group R 5 , methods known in the art are used. Thus, an aromatic acid of the formula R 5 OH, wherein R 5 is as defined above, for example benzoic acid, is reacted with the formula-XXIV compound in the presence of a dehydrating agent, e.g. sulfuric acid, zinc chloride, or phosphoryl chloride; or an anhydride of the aromatic acid of the formula (R 5 ) 2 O, for example benzoic anhydride, is used.
Preferably, however, an acyl halide, R 5 Cl, for example benzoyl chloride, is reacted with the formula-XXIV compound in the presence of a hydrogen chloride-scavenger, e.g. a tertiary amine such as pyridine, triethylamine, and the like. The reaction is carried out under a variety of conditions using procedures generally known in the art. Generally, mild conditions are employed, e.g. 20°-60° C., contacting the reactants in a liquid medium, e.g. excess pyridine or an inert solvent such as benzene, toluene or chloroform. The acylating agent is used either in stoichiometric amount or in excess.
The following examples of R 5 are available as acids (R 5 OH), anhydrides ((R 5 ) 2 O), or acyl chlorides (R 5 Cl): benzoyl; substituted benzoyl, e.g. (2-, 3- or 4-)methylbenzoyl, (2-, 3-, or 4-)ethylbenzoyl, (2-, 3-, or 4-)-isopropylbenzoyl, 2,4-dimethylbenzoyl, 3,5-dimethylbenzoyl, 2-isopropyltoluyl, 2,4,6-trimethylbenzoyl, pentamethylbenzoyl, α-phenyl-(2-, 3-, or 4-)toluyl, (2-, 3-, or 4-)-phenethylbenzoyl, 2-, 3-, or 4-nitrobenzoyl, (2,4- 2,5- or 3,5-)dinitrobenzoyl, 3,4-dimethyl-2-nitrobenzoyl, 4,5-dimethyl-2-nitrobenzoyl, 2-nitro-6-phenethylbenzoyl, 3-nitro-2-phenethylbenzoyl; mono-esterified phthaloyl, e.g. ##STR32## isophthaloyl, e.g. ##STR33## or terephthaloyl, e.g. ##STR34## (1- or 2-)naphthoyl; substituted naphthoyl, e.g. (2-, 3-, 4-, 5-, 6-, or 7-)methyl-1-naphthoyl, (2- or 4-)ethyl-1-naphthoyl, 2-isopropyl-1-naphthoyl, 4,5-dimethyl-1-naphthoyl, 6-isopropyl-4-methyl-1-naphthoyl, 8-benzyl-1-naphthoyl, (3-, 4-, 5-, or 8-)nitro-1-naphthoyl, 4,5-dinitro-1-naphthoyl, (3-, 4-, 6-, 7-, or 8-)methyl-1-naphthoyl, 4-ethyl-2-naphthoyl, and (5- or 8-)-nitro-2-naphthoyl; and acetyl. There may be employed, therefore, benzoyl chloride, 4-nitrobenzoyl chloride, 3,5-dinitrobenzoyl chloride, and the like, i.e. R 5 Cl compounds corresponding to the above R 5 groups. If the acyl chloride is not available, it is made from the corresponding acid and phosphorus pentachloride as is known in the art. It is preferred that the R 5 OH, (R 5 ) 2 O, or R 5 Cl reactant does not have bulky, hindering substituents, e.g. tert-butyl, on both of the ring carbon atoms adjacent to the carbonyl attaching-site.
The formula-XXVI compound is next obtained by deiodination of XXV using a reagent which does not react with the lactone ring or the OR 5 moiety, e.g. zinc dust, sodium hydride, hydrazine-palladium, hydrogen and Raney nickel or platinum, and the like. Especially preferred is tributyltin hydride in benzene at about 25° C. with 2,2'-azobis(2-methylpropionitrile) as initiator.
The formula-XXVII compound is obtained by demethylation of XXVI with a reagent that does not attack the OR 5 moiety, for example boron tribromide or trichloride. The reaction is carried out preferably in an inert solvent at about 0°-5° C.
The formula-XXVIII compound is obtained by oxidation of the --CH 2 OH of XXVII to --CHO, avoiding decomposition of the lactone ring. Useful for this purpose are dichromatesulfuric acid, Jones reagent, lead tetraacetate, and the like. Especially preferred is Collins' reagent (pyridineCrO 3 ) at about 0°-10° C.
The formula-XXIX compound is obtained by Wittig alkylation of XXXI, using the sodio derivative of the appropriate 2-oxo-3-phenoxy (or 3-substituted phenoxy)-alkylphosphonate. The trans enone lactone is obtained stereospecifically (see D. H. Wadsworth et al., J. Org. Chem. Vol. 30, p. 680 (1965)).
In preparing the formula-XXIX compounds of Chart B, certain phosphonates are employed in the Wittig reaction. These are of the general formula ##STR35## wherein R 2 and R 3 are hydrogen, methyl, or ethyl, being the same or different; R 7 is alkyl of one to 8 carbon atoms, inclusive; T is alkyl of one to 3 carbon atoms, inclusive, fluoro, chloro, trifluoro, or --OR 4 wherein R 4 is alkyl of one to 3 carbon atoms, inclusive, and s is zero, one, 2, or 3, with the proviso that not more than two T's are other than alkyl.
As examples of phosphonates useful for this purpose there are: ##STR36##
The phosphonates are prepared and used by methods known in the art. See Wadsworth et al., reference cited above. Conveniently, the appropriate aliphatic acid ester is condensed with the anion of dimethyl methylphosphonate produced by n-butyllithium. For this purpose, acids of the general formula ##STR37## are used in the form of their lower alkyl esters, preferably methyl or ethyl. The methyl esters, for example, are readily formed from the acids by reaction with diazomethane. These aliphatic acids of various chain length, with phenoxy or substituted-phenoxy substitution within the scope of ##STR38## as defined above are known in the art or can be prepared by methods known in the art.
Many phenoxy-substituted acids are readily available, e.g. where R 2 and R 3 are both hydrogen: phenoxy-, (o--, m--, or p--)tolyloxy-, (o--, m--, or p--)ethylphenoxy-, 4-ethyl-o-tolyloxy-, (o--, m--, or p--)propylphenoxy-, (o--, m--, or p--)-t-butylphenoxy-, (o--, m--, or p--)fluorophenoxy-, 4-fluoro-2,5-xylyloxy-, (o--, m--, or p--)chlorophenoxy-, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy-, α,α,α-trifluoro-(o--, m--, or p--)tolyloxy-, or (o--, m--, or p--)methoxyphenoxyacetic acid; where R 2 is methyl and R 3 is hydrogen: 2-phenoxy-, 2-(o--, m--, or p--)tolyloxy-, 2-(3,5-xylyloxy)-, 2-(p-fluorophenoxy)-, 2-[o--, m--, or p--)chlorophenoxy]-, 2-[2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-, 2-[(4- or 6-)chloro-o-tolyloxy]-, or 2-(α,α,α-trifluoro-m-tolyloxy)-propionic acid; wherein R 2 and R 3 are both methyl: 2-methyl-2-phenoxy-, 2-[(o-, m-, or p-)chlorophenoxy]-2-methyl-, or 2-[(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-2-methylpropionic acid; where R 2 is ethyl and R 3 is hydrogen: 2-phenoxy-, 2-[(o--, m--, or p--)fluorophenoxy]-, 2-[(o--, m--, or p--)chlorophenoxy]-, 2-[(2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-)dichlorophenoxy]-, or 2-(2-chloro-4-fluorophenoxy)-butyric acid; where R 2 is ethyl and R 3 is methyl: 2-methyl-2-phenoxy- or 2-[(o--, m--, or p--)chlorophenoxy]-2-methylbutyric acid.
Other phenoxy substituted acids are available by methods known in the art, for example, by the Williamson synthesis of ethers using an alpha-halo aliphatic acid or ester with sodium phenoxide or a substituted sodium phenoxide. Thus, the methyl ester of 2-(o-methoxyphenoxy)-2-methylbutyric acid is obtained by the following reaction: ##STR39##
The reaction proceeds smoothly with heating and the product is recovered in the conventional way. The methyl ester is used for preparing the corresponding phosphonate as discussed above.
Alternatively, the phosphonate is prepared from an aliphatic acyl halide and the anion of a dialkyl methylphosphonate. Thus, 2-methyl-2-phenoxypropionyl chloride and dimethyl methylphosphonate yield dimethyl 2-oxo-3-methyl-3-phenoxybutylphosphonate. The acyl halides are readily available from the aliphatic acids by methods known in the art, e.g. chlorides are conveniently prepared using thionyl chloride.
Continuing with Chart B, the formula-XXX compound is obtained as a mixture of alpha and beta isomers by reduction of XXIX. For this reduction, use is made of any of the known ketonic carbonyl reducing agents which do not reduce ester or acid groups or carbon-carbon double bonds when the latter is undesirable. Examples of those are the metal borohydrides, especially sodium, potassium, and zinc borohydrides, lithium (tri-tert-butoxy)aluminum hydride, metal trialkoxy borohydrides, e.g., sodium trimethoxyborohydride, lithium borohydride, diisobutyl aluminum hydride, and when carbon-carbon double bond reduction is not a problem, the boranes, e.g., disiamylborane.
For production of natural-configuration PG-type compounds, the desired 15-alpha form of the formula-XXX compound is separated from the 15-beta isomer by silica gel chromatography.
The formula-XXXI compound is then obtained by deacylation of XXX with an alkali metal carbonate, for example potassium carbonate in methanol at about 25° C.
The bis(tetrahydropyranyl) ether XXXII is obtained by reaction of the formula-XXXI diol with dihydropyran in an inert solvent, e.g. dichloromethane, in the presence of an acid condensing agent such as p-toluenesulfonic acid or pyridine hydrochloride. The dihydropyran is used in excess, preferably 4 to 10 times theory. The reaction is normally complete in 15-30 min. at 20°-30° C.
The lactol XXXIII is obtained on reduction of the formula-XXXII lactone or its 15β epimer without reducing the 13,14-ethylenic group. For this purpose, diisobutylaluminum hydride is used. The reduction is preferably done at -60° to -70° C. The 15β-epimer of the formula-XXXII lactone is readily obtained by the steps of Chart B, using the 15β isomer of formula XXX.
The formula-XXXIV compound is obtained from the formula-XXXIII lactol by the Wittig reaction, using a Wittig reagent derived from the appropriate ω-carboxyalkyltriphenylphosphonium bromide, HOOC-(CH 2 ) g+1 -P(C 6 H 5 ) 3 Br, and sodio dimethylsulfinylcarbanide. The reaction is conveniently carried out at about 25° C. This formula-XXXIV compound serves as an intermediate for preparing either the PGF 2 α -type or the PGE 2 -type product (Chart C). The phosphonium compounds are known in the art or are readily available, e.g. by reaction of an ω-bromoaliphatic acid with triphenylphosphine.
The formula-XXXV PGF 2 α -type product is obtained on hydrolysis of the tetrahydropyranyl groups from the formula-XXXIV compound, e.g. with methanol-HCl or with acetic acid/water/tetrahydrofuran at 40°-55° C.
Reference to Chart C will make clear the preparation of the PGE 2 -type products. The formula-XXXVI bis(tetrahydropyranyl) ether of the PGF 2 α -type products, either as an acid represented by formula XXIV or as an ester is oxidized at the 9-hydroxy position, preferably with Jones reagent. Finally the tetrahydropyranyl groups are replaced with hydrogen, by hydrolysis as in preparing the PGF 2 α -type product of Chart B. In Chart C, the symbols g, M, M', Q, and THP have the same meanings as in Charts A and B; R 1 is hydrogen or alkyl of one to 12 carbon atoms, inclusive, ##STR40## cycloalkyl of 3 to 10 carbon atoms, inclusive, aralkyl of 7 to 12 carbon atoms, inclusive, phenyl, or phenyl subsubstituted with one, 2, or 3 chloro or alkyl of one to 4 carbon atoms, inclusive. The esters, wherein R 1 is not hydrogen, are readily obtained by methods known in the art, e.g. reaction with diazoalkanes.
The formula-VIII PGE 1 and formula-XVIII 13,14-dihydro-PGE 1 type products of this invention are prepared by ethylenic reduction of the formula-XIII PGE 2 type compounds. Reducing agents useful for this transformation are known in the art. Thus, hydrogen is used at atmospheric pressure or low pressure with catalysts such as palladium on charcoal or rhodium on aluminum. See, for example, E.J. Corey et al., J. Am. Chem. Soc. 91, 5677 (1969) and B. Samuelsson, J. Biol. Chem. 239, 4091 (1964). For the PGE 1 type compounds, the reduction is terminated when one equivalent of hydrogen is absorbed; for the 13,14-dihydro-PGE 1 type compounds, when two equivalents are absorbed. The 13,14-dihdyro-PGE 1 compounds are also obtained by reduction of the PGE 1 compounds. For preparing the PGE 1 -type compounds it is preferred that a catalyst such as nickel boride be used which selectively effects reduction of the cis-5,6-carbon-carbon double bond in the presence of the trans-13,14 unsaturation. Mixtures of the products are conveniently separated by silica gel chromatography.
Alternatively, the bis(tetrahydropyranyl) ethers of the PGE 2 type compounds (Formula XXXVI) are reduced and subsequently hydrolyzed to remove the tetrahydropyranyl groups.
Chart D shows transformations from the formula-XXXIX PGE-type compounds to the corresponding PGF-, PGA-, and ##STR41## PGB-type compounds. In figures XXXIX, XL, XLI, and XLII of Chart D, g, M, R 2 , R 3 , T, s, and ˜ have the same meanings as in Charts A and B; R 1 has the same meanings as in Chart C; and (a) X is trans-CH═CH-- or --CH 2 CH 2 , and Y is --CH 2 CH 2 --, or (b) X is trans-CH═CH-- and Y is cis-CH═CH--. When X is trans-CH═CH-- and Y is --CH 2 CH 2 --, formula XXXIX represents PGE 1 -type compounds; when X is --CH 2 CH 2 -- and Y is --CH 2 CH 2 --, formula XXXIX represents 13,14-dihydro-PGE 1 type compounds; and when X is trans-CH═CH-- and Y is cis-CH═CH--, formula XXXIX represents PGE 2 -type compounds. Thus, formulas XXXIX, XL, XLI, and XLII embrace all of the compounds represented herein by formulas VIII-XXIII.
Thus, the various PGF.sub.β -type compounds encompassed by formulas X, XV, and XX are prepared by carbonyl reduction of the corresponding PGE-type compounds of formulas VIII, XIII, and XVIII, respectively. For example, carbonyl reduction of 16-phenoxy-18,19,20-trinor-PGE 1 gives a mixture of 16-phenoxy-18,19,20-trinor-PGF 1 α and 16-phenoxy-18,19,20-trinor-PGF 1 β. These ring carbonyl reductions are carried out by methods known in the art for ring carbonyl reductions of known prostanoic acid derivatives. See, for example, Bergstrom et al., Arkiv Kemi 19, 563 (1963), Acta. Chem. Scand. 16, 969 (1962), and British Specification No. 1,097,533. Any reducing agent is used which does not react with carbon-carbon double bonds or ester groups. Preferred reagents are lithium(tri-tert-butoxy)aluminum hydride, the metal borohydrides, especially sodium, potassium and zinc borohydrides, the metal trialkoxy borohydrides, e.g., sodium trimethoxyborohydride. The mixtures of alpha and beta hydroxy reduction products are separated into the individual alpha and beta isomers by methods known in the art for the separation of analogous pairs of known isomeric prostanoic acid derivatives. See, for example, Bergstrom et al., cited above, Granstrom et al., J. Biol. Chem. 240, 457 (1965), and Green et al., J. Lipid Research 5, 117 (1964). Especially preferred as separation methods are partition chromatographic procedures, both normal and reversed phase, preparative thin layer chromatography, and countercurrent distribution procedures.
The various PGA-type compounds encompassed by formulas XI, XVI, and XXI are prepared by acidic dehydration of the corresponding PGE-type compounds of formulas VIII, XIII, and XVIII. For example, acidic dehydration of 16-methyl-16-phenoxy-18,19,20-trinor-PGE 2 gives 16-methyl-16-phenoxy-18,19,20-trinor-PGA 2 .
These acidic dehydrations are carried out by methods known in the art for acidic dehydrations of known prostanoic acid derivatives. See, for example, Pike et al., Proc. Nobel Symposium II, Stockholm (1966), Interscience Publishers, New York, pp. 162-163 (1967); and British Specification No. 1,097,533. Alkanoic acids of 2 to 6 carbon atoms, inclusive, especially acetic acid, are preferred acids for this acidic dehydration. Dilute aqueous solutions of mineral acids, e.g., hydrochloric acid, especially in the presence of a solubilizing diluent, e.g., tetrahydrofuran, are also useful as reagents for this acidic dehydration, although these reagents may cause partial hydrolysis of an ester reactant.
The various PGB-type compounds encompassed by formulas XII, XVII, and XXII are prepared by basic dehydration of the corresponding PGE-type compounds encompassed by formulas VIII, XIII, and XVIII, respectively, or by contacting the corresponding PGA-type compounds encompassed by formulas XI, XVI, and XXI, respectively, with base. For example, both 16-(p-chlorophenoxy)-18,19,20-trinor-13,14-dihydro-PGE 1 and 16-(p-chlorophenoxy)-18,19,20-trinor-13,14-dihydro-PGA 1 give 16-(p-chlorophenoxy)-18,19,20-trinor-13,14-dihydro-PGB 1 on treatment with base.
These basic dehydrations and double bond migrations are carried out by methods known in the art for similar reactions of known prostanoic acid derivatives. See, for example, Bergstrom et al., J. Biol. Chem. 238, 3555 (1963). The base is any whose aqueous solution has pH greater than 10. Preferred bases are the alkali metal hydroxides. A mixture of water and sufficient of a water-miscible alkanol to give a homogeneous reaction mixture is suitable as a reaction medium. The PGE-type or PGA-type compound is maintained in such a reaction medium until no further PGB-type compound is formed, as shown by the characteristic ultraviolet light absorption near 278 mμ for the PGB-type compound.
Optically active compounds are obtained from optically active intermediates according to the process steps of Charts A and B. Likewise, optically active products are obtained by the transformations of optically active compounds following the processes of Charts C and D. When racemic intermediates are used in reactions corresponding to the processes of Charts A-D, inclusive, and racemic products are obtained, these racemic products may be used in their racemic form or, if preferred, they may be resolved as optically active isomers by procedures known in the art.
For example, when final compound VIII to XXIII is a free acid, the dl form thereof is resolved into the d and l forms by reacting said free acid by known general procedures with an optically active base, e.g., brucine or strychnine, to give a mixture of two diastereoisomers which are separated by known general procedures, e.g., fractional crystallization, to give the separate diastereoisomeric salts. The optically active acid of formula VIII to XXIII is then obtained by treatment of the salt with an acid by known general procedures.
As discussed above, the stereochemistry at C-15 is not altered by the transformations of Charts A and B; the 15β epimeric products of formula XXXV are obtained from 15β formula-XXX reactants. Another method of preparing the 15β products is by isomerization of the PGF 1 - or PGE 1 -type compounds having 15α configuration, by methods known in the art. See, for example, Pike et al., J. Org. Chem 34, 3552 (1969).
As discussed above, the processes of Charts B, C, and D lead variously to acids (R 1 is hydrogen) or to esters (R 1 is alkyl, cycloalkyl, aralkyl, phenyl or substituted phenyl, as defined above). When an acid has been prepared and an alkyl ester is desired, esterification is advantageously accomplished by interaction of the acid with the appropriate diazohydrocarbon. For example, when diazomethane is used, the methyl esters are produced. Similar use of diazoethane, diazobutane, and 1-diazo-2-ethylhexane, and diazodecane, for example, gives the ethyl, butyl, and 2-ethylhexyl and decyl esters, respectively.
Esterification with diazohydrocarbons is carried out by mixing a solution of the diazohydrocarbon in a suitable inert solvent, preferably diethyl ether, with the acid reactant, advantageously in the same or a different inert diluent. After the esterification reaction is complete, the solvent is removed by evaporation, and the ester purified if desired by conventional methods, preferably by chromatography. It is preferred that contact of the acid reactants with the diazohydrocarbon be no longer than necessary to effect the desired esterification, preferably about one to about ten minutes, to avoid undesired molecular changes. Diazohydrocarbons are known in the art or can be prepared by methods known in the art. See, for example, Organic Reactions, John Wiley and Sons, Inc., New York, N.Y., Vol. 8, pp 389-394 (1954).
An alternative method for esterification of the carboxyl moiety of the acid compounds comprises transformation of the free acid to the corresponding silver salt, followed by interaction of that salt with an alkyl iodide. Examples of suitable iodides are methyl iodide, ethyl iodide, butyl iodide, isobutyl iodide, tert-butyl iodide, and the like. The silver salts are prepared by conventional methods, for example, by dissolving the acid in cold dilute aqueous ammonia, evaporating the excess ammonia at reduced pressure, and then adding the stoichiometric amount of silver nitrate.
The final formula VII-to-XXIII compounds prepared by the processes of this invention, in free acid form, are transformed to pharmacologically acceptable salts by neutralization with appropriate amounts of the corresponding inorganic or organic base, examples of which correspond to the cations and amines listed above. These transformations are carried out by a variety of procedures known in the art to be generally useful for the preparation of inorganic, i.e., metal or ammonium, salts, amine acid addition salts, and quaternary ammonium salts. The choice of procedure depends in part upon the solubility characteristics of the particular salt to be prepared. In the case of the inorganic salts, it is usually suitable to dissolve the formula VIII-to-XXIII acid in water containing the stoichiometric amount of a hydroxide, carbonate, or bicarbonate corresponding to the inorganic salt desired. For example, such use of sodium hydroxide, sodium carbonate, or sodium bicarbonate gives a solution of the sodium salt. Evaporation of the water or addition of a water-miscible solvent of moderate polarity, for example, a lower alkanol or a lower alkanone, gives the solid inorganic salt if that form is desired.
To produce an amine salt, the formula VIII-to-XXIII acid is dissolved in a suitable solvent of either moderate or low polarity. Examples of the former are ethanol, acetone, and ethyl acetate. Examples of the latter are diethyl ether and benzene. At least a stoichiometric amount of the amine corresponding to the desired cation is then added to that solution. If the resulting salt does not precipitate, it is usually obtained in solid form by addition of a miscible diluent of low polarity or by evaporation. If the amine is relatively volatile, any excess can easily be removed by evaporation. It is preferred to use stoichiometric amounts of the less volatile amines.
Salts wherein the cation is quaternary ammonium are produced by mixing the formula VIII-to-XXIII acid with the stoichiometric amount of the corresponding quaternary ammonium hydroxide in water solution, followed by evaporation of the water.
The final formula VIII-to-XXIII acids or esters prepared by the processes of this invention are transformed to lower alkanoates by interaction of the formula VIII-to-XXIII hydroxy compound with a carboxyacylating agent, preferably the anhydride of a lower alkanoic acid, i.e., an alkanoic acid of two to 8 carbon atoms, inclusive. For example, use of acetic anhydride gives the corresponding acetate. Similar use of propionic anhydride, isobutyric anhydride, and hexanoic acid anhydride gives the corresponding carboxyacylates.
The carboxyacylation is advantageously carried out by mixing the hydroxy compound and the acid anhydride, preferably in the presence of a tertiary amine such as pyridine or triethylamine. A substantial excess of the anhydride is used, preferably about 10 to about 10,000 moles of anhydride per mole of the hydroxy compound reactant. The excess anhydride serves as a reaction diluent and solvent. An inert organic diluent, for example, dioxane, can also be added. It is preferred to use enough of the tertiary amine to neutralize the carboxylic acid produced by the reaction, as well as any free carboxyl groups present in the hydroxy compound reactant.
The carboxyacylation reaction is preferably carried out in the range about 0° to about 100° C. The necessary reaction time will depend on such factors as the reaction temperature, and the nature of the anhydride and tertiary amine reactants. With acetic anhydride, pyridine, and a 25° C. reaction temperature, a 12 to 24-hour reaction time is used.
The carboxyacylated product is isolated from the reaction mixture by conventional methods. For example, the excess anhydride is decomposed with water, and the resulting mixture acidified and then extracted with a solvent such as diethyl ether. The desired carboxyacylate is recovered from the diethyl ether extract by evaporation. The carboxyacylate is then purified by conventional methods, advantageously by chromatography.
By this procedure, the formula VIII, XIII, and XVIII PGE-type compounds are transformed to dialkanoates, the formula IX, X, XIV, XV, XIX, and XX PGF-type compounds are transformed to trialkanoates, and the formula XI, XVI, and XXI PGA-type and formula XII, XVII, and XXII PGB-type compounds are transformed to monoalkanoates.
When a PGE-type dialkanoate is transformed to a PGF-type compound by carbonyl reduction as shown in Chart D, a PGF-type dialkanoate is formed and is used for the abovedescribed purposes as such or is transformed to a trialkanoate by the above-described procedure. In the latter case, the third alkanoyloxy group can be the same as or different from the two alkanoyloxy groups present before the carbonyl reduction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention can be more fully understood by the following preparation and examples.
All temperatures are in degrees centigrade.
Infrared absorption spectra are recorded on a PerkinElmer model 421 infrared spectrophotometer. Except when specified otherwise, undiluted (neat) samples are used.
Mass spectra are recorded on an Atlas CH-4 mass spectrometer with a TO-4 source (ionization voltage 70 ev).
NMR spectra are recorded on a Varian A-60 spectrophotometer using solutions in deuterochloroform or other appropriate solvents with tetramethylsilane as an internal standard (downfield).
"Brine," herein, refers to an aqueous saturated sodium chloride solution.
PREPARATION 1
3α-Benzoyloxy-2β-carboxaldehyde-5α-hydroxy-1α-cyclopentaneacetic Acid γLactone (Formula XXVIII: R 5 is benzoyl)
Refer to Chart A. a. To a mixture of formula-XXIV laevorotatory (-) 3α-hydroxy-5α-hydroxy-4-iodo-2β-methoxymethyl-1α-cyclopentaneacetic acid γ-lactone (E. J. Corey et al., J. Am. Chem. Soc. 92, 297 (1970), 75 g.) in 135 ml. of dry pyridine under a nitrogen atmosphere is added 30.4 ml. of benzoyl chloride with cooling to maintain the temperature at about 20°-40° C. Stirring is continued for an additional 30 min. About 250 ml. of toluene is added and the mixture concentrated under reduced pressure. The residue is dissolved in one liter of ethyl acetate, washed with 10% sulfuric acid, brine, aqueous saturated sodium bicarbonate, and brine. The ethyl acetate solution is dried over sodium sulfate and concentrated under reduced pressure to yield an oil, 95 g. Crystallization of the oil yields the corresponding 3α-benzoyloxy compound, m.p. 84°-86° C.; [α] D +7° (CHCl 3 ); infrared spectral absorptions at 1768, 1722, 1600,, 1570, 1490, 1275, 1265, 1180, 1125, 1090, 1060, 1030, and 710 cm -1 ; and NMR (nuclear magnetic resonance) peaks at 2.1-3.45, 3.3, 3.58, 4.38, 5.12, 5.51, 7.18-7.58, and 7.83-8.05 δ.
b. The iodo group is removed as follows. To a solution of the above benzoyloxy compound (60 g.) in 240 ml. of dry benzene is added 2,2'-azobis-(2-methylpropionitrile) (approximately 60 mg.). The mixture is cooled to 15° C. and to it is added a solution of 75 g. tributyltin hydride in 600 ml. of ether, with stirring, at such a rate as to maintain continuous reaction at about 25° C. When the reaction is complete as shown by TLC (thin layer chromatography) the mixture is concentrated under reduced pressure to an oil. The oil is mixed with 600 ml. of Skellysolve B (mixed isomeric hexanes) and 600 ml. of water and stirred for 30 min. The water layer, containing the product, is separated, then combined with 450 ml. of ethyl acetate and enough solid sodium chloride to saturate the aqueous phase. The ethyl acetate layer, now containing the product, is separated, dried over magnesium sulfate, and concentrated under reduced pressure to an oil, 39 g. of the iodine-free compound. An analytical sample gives [α] D -99° (CHCl 3 ); infrared spectral absorptions at 1775, 1715, 1600, 1585, 1490, 1315, 1275, 1180, 1110, 1070, 1055, 1025, and 715 cm -1 .; NMR peaks at 2.5-3.0, 3.25, 3.34, 4.84-5.17, 5.17-5.4, 7.1-7.5, and 7.8-8.05 δ; and mass spectral peaks at 290, 168, 105, and 77.
c. The 2β-methoxymethyl compound is changed to a hydroxymethyl compound as follows. To a cold (0.5° C.) solution of the above iodine-free methoxy-methyl lactone (20 g.) in 320 ml. of dichloromethane under nitrogen is added a solution of 24.8 ml. of boron tribromide in 320 ml. of dichloromethane, dropwise with vigorous stirring over a period of 50 min. at 0°-5° C. Stirring and cooling are continued for one hr. When the reaction is complete, as shown by TLC, there is cautiously added a solution of sodium carbonate (78 g.) monohydrate in 200 ml. of water. The mixture is stirred at 0°-5° C. for 10-15 min., saturated with sodium chloride, and the ethyl acetate layer separated. Additional ethyl acetate extractions of the water layer are combined with the main ethyl acetate solution. The combined solutions are rinsed with brine, dried over sodium sulfate and concentrated under reduced pressure to an oil, 18.1 g. of the 2β-hydroxymethyl compound. An analytical sample has m.p. 116°-118° C.; [α] D -80° (CHC; 3 ); infrared spectral absorptions at 3460, 1735, 1708, 1600, 1580, 1490, 1325, 1315, 1280, 1205, 1115, 1090, 1070, 1035, 1025, 730, and 720; and NMR peaks at 2.1-3.0, 3.58, 4.83-5.12, 5.2-5.45, 7.15-7.55, and 7.8-8.0 δ.
d. The title 2β-carboxaldehyde compound is prepared as follows. To a mixture of 250 ml. of dichloromethane and Collins' reagent prepared from chromium trioxide (10.5 g.) and 16.5 ml. of pyridine, cooled to 0° C., a cold solution of the hydroxymethyl compound of step c (5.0 g.) in 50 ml. of dichloromethane is added, with stirring. After 7 min. of additional stirring, the title intermediate is used directly without isolation (see Example 1).
Following the procedure of Preparation 1, but replacing that optically active formula-XXIV iodolactone with the racemic compound of that formula and the mirror image thereof (see E. J. Corey et al., J. Am. Chem. Soc. 91, 5675 (1969)) there is obtained the racemic compound corresponding to formula XXVIII.
EXAMPLE 1
3α-Benzoyloxy-5α-hydroxy-2β-(3-oxo-4-phenoxytrans-1-butenyl)-1α-cyclopentaneacetic Acid, γ-Lactone (Formula XXIX: R 2 and R 3 are hydrogen, R 5 is benzoyl, and s is zero)
Refer to Chart B. a. There is first prepared dimethyl 3-phenoxyacetonylphosphonate. A solution of dimethyl methylphosphonate (75 g.) in 700 ml. of tetrahydrofuran is cooled to -75° C. under nitrogen and n-butyllithium (400 ml. of 1.6 molar solution in hexane) is added, keeping the temperature below -55° C. The mixture is stirred for 10 min. and to it is slowly added phenoxyacetyl chloride (44 g.), again keeping the temperature below -55° C. The reaction mixture is stirred at -75° C. for 2 hrs., then at about 25° C. for 16 hrs. The mixture is acidified with acetic acid and concentrated under reduced pressure. The residue is partitioned between diethyl ether and water, and the organic phase is dried and concentrated to the above-named intermediate, 82 g. Further treatment by silica gel chromatography yields an analytical sample having NMR peaks at 7.4-6.7 (multiplet), 4.78 (singlet), 4.8 and 4.6 (two singlets), and 3.4-3.04 (doublet) δ.
b. The phosphonate anion (ylid) is then prepared as follows. Dimethyl 3-phenoxyacetonylphosphonate (step a, 9.3 g.) is added in portions to a cold (5° C.) mixture of sodium hydride (1.75 g. of 50%) in 250 ml. of tetrahydrofuran, and the resulting mixture is stirred for 1.5 hrs. at about 25° C.
c. To the mixture of step b is added the cold solution of the formula-XXVIII 2β-carboxaldehyde of Preparation 1, and the resulting mixture is stirred about 1.6 hrs. Then 3 ml. of acetic acid is added and the mixture is concentrated under reduced pressure. A solution is prepared from the residue in 500 ml. of ethyl acetate, washed with several portions of water and brine, and concentrated under reduced pressure. The residue is subjected to silica gel chromatography, eluting with ethyl acetate-Skellysolve B (isomeric hexanes) (3:1). Those fractions shown by TLC to be free of starting material and impurities are combined and concentrated to yield the title compound, 1.7 g.; NMR peaks at 5.0-8.2 and 4.7 (singlet) δ.
Following the procedure of Example 1, but replacing the optically active formula-XXVIII aldehyde with the racemic aldehyde obtained after Preparation 1, there is obtained the racemic 3-oxo-4-phenoxy-1-butenyl compound corresponding to formula XXIX.
Following the procedure of Example 1, but replacing phenoxyacetyl chloride with each of the following aliphatic acid esters there is obtained the corresponding phosphonate and thence the formula-XXIX lactone wherein R 5 is benzoyl:
methyl 2-phenoxypropionate
methyl 2-methyl-2-phenoxypropionate
ethyl 2-phenoxybutyrate
methyl 2-ethyl-2-phenoxybutyrate
ethyl 2-methyl-2-phenoxybutyrate
methyl 2-(p-tolyloxy)acetate
methyl 2-(p-fluorophenoxy)propionate
ethyl 2-(o,p-dichlorophenoxy)-2-methyl-propionate
ethyl 2-(α,α,α-trifluoro-p-tolyloxy)butyrate and
methyl 2-(m-methoxyphenoxy)-2-methyl-butyrate.
For example, methyl 2-phenoxypropionate yields dimethyl 2-oxo-3-phenoxybutylphosphonate and, thence, the formula XXIX 3α-benzoyloxy-5α-hydroxy-2β-(3-oxo-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetic acid γ-lactone. Likewise, ethyl 2-(o,p-dichlorophenoxy)-2-methyl-propionate yields dimethyl 2-oxo-3-(o,p-dichlorophenoxy)-3-methylbutylphosphonate and, thence, the formula-XXIX 3α-benzoyloxy-5α-hydroxy-2β-[3-oxo-4-(o,p-dichlorophenoxy)-4-methyl-trans-1-pentenyl]-1α-cyclopentaneacetic acid γ-lactone.
When the phosphonate contains an asymmetric carbon atom, e.g. when the methylene between the carbonyl and the --O-- is substituted with only one methyl or ethyl group, the phosphonate exists in either of two optically active forms (+ or -) or their racemic (dl) mixture. An optically active phosphonate is obtained by starting with an appropriate optically active isomer of a phenoxy or substituted-phenoxy aliphatic acid. Methods of resolving these acids are known in the art, for example by forming salts with an optically active base such as brucine, separating the resulting diastereomers, and recovering the acids.
Following the procedure of Example 1, employing the optically active aldehyde XXVIII of that example, each optically active phosphonate obtained from the list of aliphatic acid esters above in the second paragraph following Example 1 yields a corresponding optically active formula-XXIX γ-lactone.
Likewise following the procedure of Example 1, employing the optically active aldehyde XXVIII of that example, each racemic phosphonate obtained from the above-mentioned list of aliphatic acid esters yields a pair of diastereomers, differing in their stereochemistry at the fourth carbon of the phenoxy-terminated side-chain. These diastereomers are separated by conventional methods, e.g. by silica gel chromatography.
Again following the procedure of Example 1, employing the optically active aldehyde XXVIII of that example, each of the optically inactive phosphonates obtained from the list of aliphatic acid esters above wherein there is no asymmetric carbon atom, i.e. R 2 and R 3 are the same, yields a corresponding optically active formula-XXIX γ-lactone.
Replacing the optically active aldehyde XXVIII with the racemic aldehyde obtained after Preparation 1, and following the procedure of Example 1 using each of the optically active phosphonates described above, there is obtained in each case a pair of diastereomers which are separated by chromatography.
Likewise following the procedure of Example 1, employing the racemic aldehyde with each of the racemic phosphonates described above, there are obtained in each case two pairs of 3-oxo-4-phenoxy (or substituted-phenoxy) racemates which are separated into pairs of racemic compounds by methods known in the art, e.g. silica gel chromatography.
Again following the procedure of Example 1, employing the racemic aldehyde with each of the optically inactive phosphonates described above, there are obtained in each case a racemic product corresponding to formula XXIX.
EXAMPLE 2
3α-Benzoyloxy-5α-hydroxy-2β-(3α-hydroxy-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic Acid, γ-Lactone (Formula XXX: M is ##STR42## Q is ##STR43## and R 5 is benzoyl); and the 3β-hydroxy isomer (Formula XXX: M is ##STR44##
Refer to Chart B. Sodium borohydride (1.05 g.) is added in portions to a cold (0° C.) mixture of zinc chloride (4.4 g.) and 35 ml. of 1,2-dimethoxyethane under nitrogen. Stirring is continued at about 25° C. for 20 hrs. Then the mixture is cooled to -20° C. and the formula-XXIX 3-oxo compound (Example 1, 2.6 g. in 10 ml. of 1,2-dimethoxyethane) is added. The mixture is stirred at -20° C. for 6 hrs., and at 25° C. for 30 min. The mixture is again cooled to -20° C. and 5 ml. of water is added dropwise. The mixture is shaken with 100 ml. of brine and ethyl acetate and the organic layer is dried and concentrated under reduced pressure. The residue is chromatographed on silica gel, eluting with ethyl acetate-Skellysolve B (isomeric hexanes) (3:1). Those fractions shown by TLC to be free of starting material and impurities are combined and concentrated to yield the 3α-hydroxy title compound, 1.1 g.; NMR peaks at 6.6-8.0, 5.52-5.87, and 3.83 δ. Other fractions yield the more polar 3β-hydroxy title compound, 0.8 g.; NMR peaks at 6.6-8.0, 5.52-5.87, and 3.83 δ.
Following the procedure of Example 2, but using the racemic 3-oxo-4-phenoxy-1-butenyl compound obtained following Example 1, there are obtained the corresponding racemic 3-hydroxy products.
Likewise following the procedure of Example 2, each of the optically active or racemic lactones corresponding to formula XXIX described following Example 1 is transformed to the optically active or racemic compound corresponding to formula XXX.
EXAMPLE 3
3α,5α-Dihydroxy-2β-(3α-hydroxy-4-phenoxytrans-1-butenyl)-1α-cyclopentaneacetaldehyde γ-Lactol Bis(tetrahydropyranyl) Ether (Formula XXXIII: M' is ##STR45## Q is ##STR46## and ˜ is alpha or beta).
Refer to Chart B. a. The formula-XXX 3α-hydroxy compound (Example 2, 1.35 g.) in 22 ml. of anhydrous methanol is stirred with potassium carbonate (0.48 g.) for 1 hr. at about 25° C. Then 15 ml. of chloroform is added and the solvent removed under reduced pressure. A solution of the residue in 70 ml. of chloroform is shaken with 10 ml. of water containing potassium hydrogen sulfate (0.5 g.), then with brine, and concentrated. The residue is washed with several portions of Skellysolve B (isomeric hexanes) and dried to yield the formula-XXXI benzoyloxy-free compound, i.e. 3α,5α-dihydroxy-2β-(3α-hydroxy-4-phenoxy-trans-1-butenyl)-1α-cyclopentaneacetic acid, γ-lactone, 0.4 g.
b. The formula-XXXI compound from part a above is converted to the formula-XXXII bis(tetrahydropyranyl) ether by reaction with 0.8 ml. of dihydropyran in 10 ml. of dichloromethane in the presence of pyridine hydrochloride (about 0.03 g.). In about 2.5 hrs. the mixture is filtered and concentrated to the formula-XXXII product, 0.6 g.; having no infrared absorption at 3300 cm -1 .
c. The title compound is prepared as follows. Diisobutylaluminum hydride (4.8 ml. of a 10% solution in toluene) is added dropwise to a stirred solution of the formula-XXXII bis(tetrahydropyranyl) ether from part b above in 8 ml. of toluene cooled to -78° C. Stirring is continued at -78° C. for 0.5 hr., whereupon a solution of 3 ml. of tetrahydrofuran and 1 ml. of water is added cautiously. After the mixture warms to 25° C. it is filtered and the filtrate washed with brine, dried, and concentrated to the mixed alpha and beta hydroxy isomers of the formula-XXXIII title compounds, 0.33 g., having infrared absorption at 3300 cm -1 .
Following the procedures of Example 3, but using the formula-XXX 3β-hydroxy-4-phenoxy isomer of Example 2, there is obtained the corresponding 3β-hydroxy formula-XXXIII compound, i.e. wherein M' is ##STR47##
Likewise following the procedures of Example 3, each of the optically active or racemic compounds corresponding to formula XXX described following Example 2 is transformed to an optically active or racemic compound corresponding to formula XXXIII. There are thus obtained both the 3α- and 3β-hydroxy isomers.
EXAMPLE 4
16-Phenoxy-17,18,19,20-tetranor-PGF 2 α, 11,15-Bis(tetrahydropyranyl) Ether (Formula XXXIV: g is 3, M' is ##STR48## and Q is ##STR49##
Refer to Chart B. 4-Carboxybutyltriphenylphosphonium bromide (E. J. Corey et al., J. Am. Chem. Soc. 91, 5677 (1969)) (0.9 g.) is added to a solution of sodio dimethylsulfinylcarbanide prepared from sodium hydride (0.195 g.) and 5 ml. of dimethylsulfoxide (DMSO). To this Wittig reagent is added dropwise a solution of the formula-XXXIII lactol (Example 3, 0.33 g.) in 2 ml. of DMSO. The mixture is stirred at about 25° C. for 2 hrs., then diluted with 20 ml. of benzene. To the mixture is added, with stirring, a solution of potassium hydrogen sulfate (0.7 g.) in 5 ml. of water. The organic layer is separated, washed with water and brine, then dried and concentrated to an oil, 1.7 g. This residue is subjected to silica gel chromatography, eluting with 0-20% acetone in dichloromethane. Those fractions shown by TLC to contain the product free of starting material and impurities are combined and concentrated to yield the title compound, 0.3 g.; NMR peaks at 6.7-7.3, 5.2-5.75, 4.6, and 3.68 δ.
EXAMPLE 5
16-Phenoxy-17,18,19,20-tetranor-PGF 2 α (Formula XIV: g is 3; M is ##STR50## R 1 , R 2 , and R 3 are hydrogen; and s is zero)
Refer to Chart B. A solution of the formula-XXXIV bis(tetrahydropyranyl) ether (Example 4, 0.3 g.) in 5 ml. of methanol, 0.2 ml. of hydrochloric acid, and 2 ml. of water is stirred at about 25° C. for 1.5 hrs. The solution is made basic to pH 8-9 with dilute sodium hydroxide and extracted with dichloromethane. The aqueous phase is then acidified to pH 2 with dilute hydrochloric acid and extracted with ethyl acetate. The organic phase is dried and concentrated under reduced pressure to an oil. The oil is chromatographed on silica gel, eluting with 0-10% methanol in ethyl acetate. Those fractions shown by TLC to contain the product free of starting material and impurities are combined and concentrated to yield the title compound, 0.06 g.; mass spectral peaks (trimethylsilyl derivative) at 678, 663, 578, 561, 481, and 391; NMR peaks at 6.7-7.3, 5.5-5.7, and 5.0-5.4 δ.
Following the procedures of Examples 4 and 5, each of the optically active or racemic 3α-hydroxy compounds corresponding to formula XXXIII described following Example 3 is transformed to the corresponding bis(tetrahydropyranyl) ether and thence to the corresponding 16-phenoxy (or substituted-phenoxy)-PGF 1 α type compound or racemic mixture. There are thus obtained the following compounds from the 3α-hydroxy isomers:
16-phenoxy-17,18,19,20-tetranor-PGF 2 α
16-phenoxy-18,19,20-trinor-PGF 2 α
16-methyl-16-phenoxy-18,19,20-trinor-PGF 2 α
16-phenoxy-19,20-dinor-PGF 2 α
16-ethyl-16-phenoxy-19,20-dinor-PGF 2 α
16-methyl-16-phenoxy-19,20-dinor-PGF 2 α
16-(p-tolyloxy)-17,18,19,20-tetranor-PGF 2 α
16-(p-fluorophenoxy)-18,19,20-trinor-PGF 2 α
16-(o,p-dichlorophenoxy)-16-methyl-18,19,20-trinor-PGF 2 α
16-(α,α,α-trifluoro-p-tolyloxy)-19,20-dinor-PGF 2 .alpha.
16-methyl-16-(m-methoxyphenoxy)-19,20-dinor-PGF 2 α and their racemic mixtures, for example dl-16-phenoxy-17,18,19,20-tetranor-PGF 2 α.
Likewise following the procedures of Examples 4 and 5 but employing the above-described 3β-hydroxy compounds corresponding to formula XXXIII, there are obtained the corresponding 15β-epimers and their racemic mixtures for example:
16-phenoxy-17,18,19,20-tetranor-15β-PGF 2 α
16-phenoxy-18,19,20-trinor-15β-PGF 2 α
16-methyl-16-phenoxy-18,19,20-trinor-15β-PGF 2 α
Following the procedures of Examples 4 and 5, but replacing 4-carboxybutyltriphenylphosphonium bromide with a phosphonium bromide within the scope of HOOC-(CH 2 ) g+1 --P(C 6 H 5 ) 3 Br wherein g is 2, 4, or 5, namely
3-carboxypropyltriphenylphosphonium bromide,
5-carboxypentyltriphenylphosphonium bromide, or
6-carboxyhexyltriphenylphosphonium bromide,
each of the optically active or racemic 3α-hydroxy compounds corresponding to formula XXXIII described following Example 3 is transformed to a bis(tetrahydropyranyl) ether corresponding to formula XXXIV wherein the carboxy-terminated side chain has six, eight, or nine carbon atoms, and, thence, to the corresponding 16-phenoxy (or substituted-phenoxy)-PGF 2 α type compound or racemic mixture, for example:
16-phenoxy-2,17,18,19,20-pentanor-PGF 2 α
16-phenoxy-2a-homo-18,19,20-trinor-PGF 2 α
16-methyl-16-phenoxy-2a,2b-dihomo-19,20-dinor-PGF 2 α
16-phenoxy-2,19,20-trinor-PGF 2 α
16-ethyl-16-phenoxy-2a-homo-19,20-dinor-PGF 2 α
16-methyl-16-phenoxy-2a,2b-dihomo-19,20-dinor-PGF 2 α
16-(p-tolyloxy)-2,17,18,19,20-pentanor-PGF 2 α
16-(p-fluorophenoxy)-2a-homo-18,19,20-trinor-PGF 2 α
16-(o,p-dichlorophenoxy)-16-methyl-2a,2b-dihomo-18,19,20-trinor-PGF 2 .alpha.
16-(α,α,α-trifluoro-p-tolyloxy)-2,19,20-trinor-PGF 2 .alpha.
16-methyl-16-(m-methoxyphenoxy)-2a-homo-19,20-dinor-PGF 2 α
and their racemic mixtures, for example dl-16-phenoxy-2,17,-18,19,20-pentanor-PGF 2 α.
Likewise following the procedures of Examples 4 and 5 but employing with the various phosphonium bromides the 3β-hydroxy compounds corresponding to formula XXXIII described following Example 3, there are obtained the corresponding 15β epimers first as the bis(tetrahydropyranyl) ethers and then as the PGF 2 α type products and their racemic mixtures, for example
16-phenoxy-2,17,18,19,20-pentanor-15β-PGF 2 α and
dl-16-phenoxy-2,17,18,19,20-pentanor-15β-PGF 2 α.
EXAMPLE 6
16-Phenoxy-17,18,19,20-tetranor-PGE 2 Methyl Ester (Formula XIII: g is 3, M is ##STR51## R 1 is methyl, R 2 and R 3 are hydrogen, and s is zero)
Refer to Chart C. a. There is first prepared the methyl ester of the formula-XXXIV 11,15-bis(tetrahydropyranyl) ether of 16-phenoxy-17,18,19,20-tetranor PGF 2 α. A solution of that formula-XXXIV compound (Example 4, 1.35 g.) in 10 ml. of diethyl ether is mixed with a solution of diazomethane (about 0.5 g.) in 25 ml. of diethyl ether and stirred for about 3 min. Two ml. of acetic acid is added, then about 50 ml. of ether, and the solution shaken with aqueous sodium bicarbonate solution. The organic phase is concentrated under reduced pressure to an oil. The oil is chromatographed on silica gel, eluting with ethyl acetateSkellysolve B (isomeric hexanes) (3:1). The methyl ester is obtained, 0.42 g., NMR peak at 3.57 (singlet) δ, and infrared absorption at 1745 cm -1 .
b. A solution of the product of step a (0.42 g.) in 12 ml. of acetone is cooled to about -20° C. and to it is added slowly 0.5 ml. of Jones reagent (2.1 g. of chromium trioxide, 6 ml. of water, and 1.7 ml. of concentrated sulfuric acid). The mixture is stirred for 15 min., and then shaken with 30 ml. of ice water and 200 ml. of dichloromethane-diethyl ether (1:3). The organic phase is washed with cold dilute hydrochloric acid, cold water, and brine, then dried and concentrated. The residue is the bis(tetrahydropyranyl) ether of the title compound, an oil, 0.35 g., having infrared absorption at 1740 cm -1 .
c. A solution of the product of step b in 9.5 ml. of acetic acid and 4.5 ml. of water is stirred at 37°-39° C. for 2.5 hrs. The mixture is neutralized with sodium bicarbonate solution, then saturated with salt and shaken with dichloromethane-diethyl ether (1:3), dried and concentrated. The residue is chromatographed on silica gel, eluting with 25% ethyl acetate in Skellysolve B (isomeric hexanes), and 0-6% methanol in ethyl acetate. The fractions shown by TLC to contain the desired product free of starting material and impurities are combined and concentrated to yield the title compound, 0.10 g.; NMR peaks at 7.5-6.6, 5.7, 5.3, and 3.6 (singlet) δ; infrared absorption bands at 3300, 1740, and 1730 cm -1 ; mass spectral peaks at (trimethylsilyl derivative) at 546, 531, 515, 439, and 349.
EXAMPLE 7
16-Methyl-16-phenoxy-18,19,20-trinor-PGF 2 α (Formula XIV: g is 3, M is ##STR52## R 1 is hydrogen, R 2 and R 3 are methyl, s is zero, and ˜ is alpha)
Refer to Chart B. a. There is first prepared dimethyl 2-oxo-3-methyl-3-phenoxybutylphosphonate. For this purpose, 2-methyl-2-phenoxypropionyl chloride is made by reaction of 2-methyl-2-phenoxypropionic acid (50 g.) with thionyl chloride (82 g.), first at about 25° C., then on a steam bath, finally pumping off excess thionyl chloride with addition of toluene.
A solution of dimethyl methylphosphonate (69.5 g.) in 700 ml. of tetrahydrofuran is cooled to -75° C. under nitrogen and n-butyllithium (355 ml. of 1.6 molar solution in hexane) is added, keeping the temperature below -55° C. The mixture is stirred for 10 min. and to it is slowly added a solution of the 2-methyl-2-phenoxypropionyl chloride above in 50 ml. of tetrahydrofuran, again keeping the temperature below -55° C. The reaction mixture is stirred at -75° C. for 2 hrs., then at about 25° C. for 16 hrs. The mixture is acidified with acetic acid (25 ml.), and the supernatant liquid is concentrated under reduced pressure. The residue is partitioned between water and dichloromethanediethyl ether (3:1). The organic phase is washed with brine, then with saturated sodium bicarbonate, dried over sodium sulfate, and concentrated. Further treatment by silica gel chromatography yields 55 g.; NMR peaks at 6.74-7.4, 3.85, 3.65, 3.56, 3.21 and 1.45 (singlet) δ.
b. Following the procedures of Example 1, steps b and c, but utilizing the above phosphonate instead of the dimethyl 3-phenoxyacetonylphosphonate of that example, there is obtained the corresponding formula-XXIX intermediate, i.e. 3α-benzoyl-5α-hydroxy-2β-(3-oxo-4-methyl-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetic acid, γ-lactone, 12.7 g.; m.p. 145°-147° C. (recrystallized from diethyl ether-pentane); NMR peaks at 6.62-7.65, 4.80, 5.46, 1.45, and 1.48 δ.
c. Following the procedure of Example 2, but utilizing the above formula-XXIX compound instead of the formula-XXIX compound of that example, there are obtained the corresponding formula-XXX α- and β-hydroxy isomers, i.e. 3α-benzoyloxy-5α-hydroxy-2β-(3α-hydroxy-4-methyl-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetic acid, γ-lactone, 7.7 g., m.p. 121°-122° C.; NMR peaks at 7.90-8.25, 6.95-7.74, 5.85-5.95, 4.19-4.3, and 1.15 (singlet) δ; and 3α-benzoyloxy-5α-hydroxy-2β-(3β-hydroxy-4-methyl-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetic acid, γ-lactone, 3.65 g., having similar NMR peaks.
d. Following the procedures of Example 3, the 3α-hydroxy intermediate of step c above (8.54 g.) is transformed first to the formula-XXXI benzoyloxy-free compound, i.e. 3α,5α-dihydroxy-2β-(3α-hydroxy-4-methyl-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetic acid, γ-lactone, 6.18 g.; m.p. 65°-66° C.; NMR peaks at 6.86-7.40, 5.62-5.73, 3.47 (singlet) and 1.18 (singlet) δ. Next the corresponding formula-XXXII bis(tetrahydropyranyl) ether is prepared following the procedure of Example 3-b; yield 8.8 g.; infrared absorption spectrum free of hydroxyl absorption at 3300 cm -1 . Then the formula-XXXIII lactol is prepared following the procedure of Example 3-c; yield of 3α,5α-dihydroxy-2β-(3α-hydroxyl-4-methyl-4-phenoxy-trans-1-pentenyl)-1α-cyclopentaneacetaldehyde, γ-lactol, bis(tetrahydropyranyl) ether, 9.16 g.; infrared absorption spectrum free of γ-lactone absorption at 1760 cm -1 .
e. Following the procedures of Example 4, the lactol of step d above is transformed by the Wittig reaction, starting with 4 carboxybutyltriphenylphosphonium bromide, to the corresponding formula-XXXIV bis(tetrahydropyranyl) ether of the title compound, yield 7.6 g.; NMR peaks at 7.1-7.3, 6.4 (singlet), 5.3-5.82, 4.6-5.0, and 3.3-4.3 δ.
f. A solution of the formula-XXXIV bis(tetrahydropyranyl) ether of step e above (2.4 g.) in 50 ml. of acetic acid and 25 ml. of water is stirred at about 25° C. for 16 hrs. and then at 37°-39° C. for 1.5 hrs. The product is freeze-dried and then chromatographed on silica gel, eluting with 0-3% methanol in ethyl acetate. Those fractions shown by TLC to contain the product free of starting material and impurities are combined and concentrated to yield the title compound, 0.60 g.; mass spectral peaks (trimethylsilyl derivative) at 706, 691, 613, 601, 571 and 481; NMR peaks at 6.95-7.45, 5.6-5.8, 5.0-5.6, and 3.4-5.0 δ.
EXAMPLE 8
16-Methyl-16-phenoxy-18,19,20-trinor-PGE 2 (Formula XIII: g is 3, M is ##STR53## R 1 is hydrogen, R 2 and R 3 are methyl, and s is zero)
Refer to Chart C. A solution of the formula-XXIV 16-methyl-16-phenoxy-18,19,20-trinor-PGF 2 α, 11,15-bis(tetrahydropyranyl) ether (Example 73, 5.2 g.) in 100 ml. of acetone is cooled to about -20° C. and to it is added slowly 5 ml. of Jones reagent. The mixture is stirred for 15 min., diluted with 600 ml. of ethyl acetate and 600 ml. of diethyl ether, and washed with dilute hydrochloric acid and brine, then dried over magnesium sulfate and concentrated under reduced pressure to an oil.
The above oil, which is the formula-XXXVII bis(tetrahydropyranyl) ether of the title compound, is dissolved in 80 ml. of acetic acid and 40 ml. of water and stirred at 40° C. for 2.5-3 hrs. The product is freeze dried and then chromatographed on silica gel, eluting with 0.75-1.5% methanol in ethyl acetate. Those fractions shown by TLC to contain the product free of starting material and impurities are combined and concentrated to yield the title compound, 2.0 g.; infrared absorption bonds at 2700-3500, 1750, 1715, 1600, and 1500 cm -1 ; NMR peaks at 6.87-7.4, 6.35, 5.6-5.87, 5.2-5.5, 3.8-4.3 δ; mass spectral peaks (trimethylsilyl derivative) at 632, 617, 539, 527, and 497.
Following the procedures of Example 8, each of the bis(tetrahydropyranyl) ethers corresponding to formula XXXIV described following Example 5 is transformed to the corresponding 16-phenoxy (or substituted-phenoxy)-PGE 2 type compound or its racemic mixtures, for example
16-phenoxy-17,18,19,20-tetranor-PGE 2
16-phenoxy-2,17,18,19,20-pentanor-PGE 2
dl-16-phenoxy-17,18,19,20-tetranor-PGE 2 and
dl-16-phenoxy-2,17,18,19,20-pentanor-PGE 2 .
From the 15β-epimers are obtained the corresponding 15β-PGE 2 type epimers, for example
16-phenoxy-17,18,19,20-tetranor-15β-PGE 2 and
dl-16-phenoxy-17,18,19,20-tetranor-15β-PGE 2 .
As in Example 8, there is first obtained the bis(tetrahydropyranyl) ether of the PGE 2 type compound in each instance.
EXAMPLE 9
16-Methyl-16-phenoxy-18,19,20-trinor-PGE 2 , Methyl Ester (Formula XIII: g is 3; M is ##STR54## R 1 , R 2 , and R 3 are methyl; and s is zero), and 16-Methyl-16-phenoxy-18,19,20-trinor-PGA 2 , Methyl Ester (Formula XVI: g is 3; M is ##STR55## R 1 , R 2 , and R 3 are methyl; and s is zero)
Refer to Chart C. a. Following the procedure of Example 6a, and using the product of Example 7e above, there is first prepared the formula-XXXVI methyl ester of 16-methyl-16-phenoxy-18,19,20-trinor-PGF 2 α, 11,15-bis-(tetrahydropyranyl) ether, in quantitative yield, having R f =0.8 on silica gel (using as TLC solvent system the organic phase from 500 ml. ethyl acetate, 5 ml. methanol, and 50 ml. water, well-shaken).
b. Following the procedure of Example 6b, the methyl ester of part a, above, (9.8 g.) is oxidized with Jones reagent to the corresponding PGE 2 -type product.
c. The formula-XXXVII 16-methyl-16-phenoxy-18,19,20-trinor-PGE 2 , 11,15-bis(tetrahydropyranyl) ether, methyl ester of part b above is taken up in 210 ml. of acetic acid, 105 ml. of water, and 35 ml. of tetrahydrofuran. The solution is stirred at 40°-45° C. for 4 hrs., then freeze-dried. The residue is taken up in diethyl ether, washed with cold, dilute sodium bicarbonate solution, dried, and concentrated to a mixture of the title compound, 6.2 g.
d. The mixture from part c is chromatographed on silica gel (800 g.) wet packed in ethyl acetate-hexane (1:1). The column is eluted in 60 ml. fractions with the following solvent mixtures: fractions 1-20, 60% ethyl acetate-40% hexane; fractions 21-40, 70% ethyl acetate-30% hexane; fractions 41-60, 80% ethyl acetate-20% hexane; fractions 61-80, ethyl acetate; fractions 81-100, 2% methanol in ethyl acetate. Fractions 34-44 yield the formula-XVI PGA 2 -type title compound, 0.48 g.; NMR peaks at 7.56, 7.52, 7.48, 7.44, 6.24, 6.20, 6.14, 6.10, 7.31-6.86, 5.82-5.65, 5.48-5.30, 3.63 (singlet) and 1.28 (singlet) δ; mass spectral peaks (trimethylsilyl derivative) at 484, 453, 451, 407, 391, 350, 260, and 135. Fractions 73-100 yield the formula-XIII PGE 2 -type title compound, 3.0 g.; NMR peaks at 7.30-6.87, 5.82-5.65, 5.48-5.30, 3.64 (singlet), 1.25, and 1.21 δ; mass spectral peaks (trimethylsilyl derivative) at 574, 543, 484, 481, 469, 439, 391, and 135.
EXAMPLE 10
16-Methyl-16-phenoxy-18,19,20-trinor-PGF 2 α, Methyl Ester (Formula XIV: g is 3; M is ##STR56## R 1 , R 2 , and R 3 are methyl; s is zero; and ˜ is alpha)
A solution of 16-methyl-16-phenoxy-18,19,20-trinor-PGF 2 α, 11,15-bis(tetrahydropyranyl) ether, methyl ester (Example 9a, 4.0 g.) in 90 ml. of acetic acid, 45 ml. of water and 15 ml. of tetrahydrofuran is stirred at 40°-45° C. for 4 hrs. The reaction mixture is diluted with 150 ml. of water, frozen, and lyophilized. The residue is taken up in ether and washed with ice-cold dilute sodium bicarbonate solution. The organic phase is dried over sodium sulfate and concentrated under reduced pressure. The residue is chromatographed on silica gel, eluting with 0-20% methanol in ethyl acetate. Those fractions shown by TLC to contain the product free of starting material and impurities are combined and concentrated to yield the title compound, 2.08 g.; NMR peaks at 7.38-6.86, 5.72-5.62, 5.50-5.28, 3.66 (singlet), and 1.22 (singlet) δ; mass spectral peaks (trimethylsilyl derivative) at 633, 617, 555, 513, 423, and 135.
EXAMPLE 11
16-Methyl-16-phenoxy-18,19,20-trinor-PGF 2 β (Formula XV: g is 3; M is ##STR57## R 1 is hydrogen; R 2 , and R 3 are methyl; and s is zero)
Refer to Chart D. A solution of sodium borohydride (300 mg.) in 6 ml. of ice-cold methanol is added to a solution of 16-methyl-16-phenoxy-18,19,20-trinor-PGE 2 (Example 8, 650 mg.) in 30 ml. of methanol at -5° C. The mixture is stirred for an additional 5 min., made slightly acidic with acetic acid, and concentrated under reduced pressure. The residue is extracted with dichloromethane and the organic phase is washed with water, dilute aqueous sodium bicarbonate, and brine, then dried over sodium sulfate and concentrated under reduced pressure. This residue is chromatographed over silica gel, eluting with 0-10% ethanol in ethyl acetate. Those fractions containing the title compound free of starting material and impurities, as shown by TLC, are combined and concentrated to yield the formula-XV title compound. In other fractions the corresponding formula XIV PGF 2 α -type compound is obtained.
Following the procedure of Example 11, each of the 16-phenoxy (or substituted-phenoxy)-PGE 2 type compounds, their 15β epimers, and racemates described following Example 8 is transformed to the corresponding 16-phenoxy (or substituted-phenoxy)-PGF 2 β type compound or 15β epimer or racemic mixture. There are also obtained the corresponding PGF 2 α -type compounds.
EXAMPLE 12
16-Phenoxy-17,18,19,20-tetranor-PGA 2 (Formula XVI: g is 3; M is ##STR58## R 1 , R 2 , and R 3 are hydrogen; and s is zero)
Refer to Chart D. A solution of 16-phenoxy-17,18,19,-20-tetranor-PGE 2 methyl ester (Example 6, 300 mg.), 4 ml. of tetrahydrofuran and 4 ml. of 0.5 N. hydrochloric acid is left standing at 25° C. for 5 days. Brine and dichloromethane-ether (1:3) are added and the mixture is stirred. The organic phase is separated, dried, and concentrated. The residue is dissolved in diethyl ether and the solution is extracted with saturated aqueous sodium bicarbonate. The aqueous phase is acidified with dilute hydrochloric acid and then extracted with dichloromethane. This extract is dried and concentrated to yield the formula-XVI title compound.
Following the procedure of Example 12, each of the 16-phenoxy (or substituted-phenoxy)-PGE 2 type compounds, 15β epimers, and racemates, described following Example 8 is transformed to the corresponding 16-phenoxy (or substituted-phenoxy)-PGA 2 type compound or 15β epimer or racemic mixture.
EXAMPLE 13
16-Phenoxy-17,18,19,20-tetranor-PGB 2 (Formula XVII: g is 3; M is ##STR59## R 1 , R 2 , and R 3 are hydrogen; and s is zero)
Refer to Chart D. A solution of 16-phenoxy-17,18,19,-20-tetranor-PGE 2 methyl ester (Example 6, 200 mg.) in 100 ml. of 50% aqueous ethanol containing about one gram of potassium hydroxide is kept at 25° C. for 10 hrs. under nitrogen. The solution is then cooled to 10° C. and neutralized by addition of 3N. hydrochloric acid at 10° C. The resulting solution is extracted repeatedly with ethyl acetate, and the combined ethyl acetate extracts are washed with water and then with brine, dried, and concentrated to yield the formula-XVII title compound.
Following the procedure of Example 13, each of the 16-phenoxy (or substituted-phenoxy)-PGE 2 type compounds, their 15β epimers, and racemates, described following Example 8 is transformed to the corresponding 16-phenoxy (or substituted-phenoxy)-PGB 2 type compound or 15β epimer or racemic mixture.
EXAMPLE 14
16-Methyl-16-Phenoxy-18,19,20-trinor-PGE 1 (Formula VIII: g is 3; M is ##STR60## R 1 is hydrogen; R 2 and R 3 are methyl; and s is zero) and 16-Methyl-16-Phenoxy-18,19,20-trinor-13,14-dihydro-PGE 1 (Formula XVIII: g is 3; M is ##STR61## R 1 is hydrogen; R 2 and R 3 are methyl; and s is zero)
A mixture of the formula-XXXVII bis(tetrahydropyranyl) ether of 16-methyl-16-phenoxy-18,19,20-trinor-PGE 2 (Example 8, 220 mg.), 5% rhodium-on-alumina catalyst (40 mg.), and 16 ml. of ethyl acetate is stirred under one atmosphere of hydrogen at about 0° C. until substantially all of the starting material has been used, as shown by TLC. The mixture is filtered to remove catalyst, and the filtrate is concentrated. The residue is dissolved in 1 ml. of tetrahydrofuran and 6 ml. of 66% acetic acid and the mixture is warmed to 50° C. for 2.5 hrs. The mixture is concentrated under reduced pressure and the residue is chromatographed over silica gel, eluting with the upper layer of a mixture of ethyl acetate-acetic acid-Skellysolve B (isomeric hexanes)-water (90:20:50:100). Those fractions shown by TLC to contain the title compounds free of starting material and impurities are combined and concentrated to yield the title compounds.
Following the procedure of Example 14, each of the PGE 2 -type bis(tetrahydropyranyl) ethers described following Example 8 is transformed to the corresponding 16-phenoxy (or substituted-phenoxy)-PGE 1 type or 13,14-dihydro-PGE 1 type compound, 15β epimer, or racemate.
EXAMPLE 15
16-Phenoxy-17,18,19,20-tetranor-13,14-dihydro-PGE 1 Methyl Ester (Formula XVIII: g is 3; M is ##STR62## R 1 is methyl; R 2 and R 3 are hydrogen; and s is zero)
A solution of 16-phenoxy-17,18,19,20-tetranor-PGE 2 methyl ester (Example 6, 100 mg.) in 10 ml. of ethyl acetate is shaken with hydrogen at about one atmosphere pressure at 25° C. in the presence of a 5% palladium-on-charcoal catalyst (15 mg.). Two equivalents of hydrogen are used, whereupon the hydrogenation is stopped and the catalyst is removed by filtration. The filtrate is concentrated under reduced pressure and the residue is chromatographed on silica gel, eluting with ethyl acetate-Skellysolve B (isomeric hexanes) ranging from 50-100% ethyl acetate. Those fractions shown by TLC to contain the desired product free of starting material and impurities are combined and concentrated to give the title compound.
Following the procedures of Examples 11, 12, and 13, each of the 16-phenoxy (or substituted-phenoxy)-PGE 1 type or 13,14-dihydro-PGE 1 type compounds, 15β epimers or racemates described in and following Examples 14 and 15 is transformed respectively to the corresponding 16-phenoxy (or substituted-phenoxy)-PGF 1 α, -PGF 1 β, -PGA 1 , or PGB 1 type or 16-phenoxy (or substituted-phenoxy)-13,14-dihydro-PGF 1 α, -PGF 1 β, -PGA 1 , or -PGB 1 type compound, 15β epimer or racemate.
EXAMPLE 16
16-Phenoxy-17,18,19,20-tetranor-PGF 2 α Methyl Ester (Formula XIV: g is 3, M is ##STR63## R 1 is methyl, R 2 and R 3 are hydrogen, s is zero and ˜ is alpha)
A solution of diazomethane (about 0.5 g.) in 25 ml. of diethyl ether is added to a solution of 16-phenoxy-17,18,-19,20-tetranor-PGF 2 α (Example 5, 50 mg.) in 25 ml. of a mixture of methanol and diethyl ether (1:1). After the mixture has stood at about 25° C. for 5 min., it is concentrated under reduced pressure to yield the title compound.
Following the procedure of Example 16, each of the other 16-phenoxy (or substituted-phenoxy)-PGF-type, PGE-type, PGA-type, and PGB-type free acids and also their 15β-epimers and racemates defined above is converted to the corresponding methyl ester.
Likewise following the procedure of Example 16, but replacing diazomethane with diazoethane, diazobutane, 1-diazo-2-ethylhexane, and diazodecane, there are obtained the corresponding ethyl, butyl, γ-ethylhexyl, and decyl esters of 16-phenoxy-17,18,19,20-tetranor-PGF 2 α. In the same manner, each of the other 16-phenoxy (or substituted-phenoxy)-PGF-type, PGE-type, PGA-type, and PGB-type free acids and also their 15β-epimers and racemates defined above is converted to the corresponding ethyl, butyl, 2-ethylhexyl, and decyl esters.
EXAMPLE 17
16-Phenoxy-17,18,19,20-tetranor-PGF 2 α Sodium Salt
A solution of 16-phenoxy-17,18,19,20-tetranor-PGF 2 α (Example 5, 100 mg.) in 50 ml. of a water-ethanol mixture (1:1) is cooled to 5° C. and neutralized with an equivalent amount of 0.1 N. aqueous sodium hydroxide solution. The neutral solution is concentrated to a residue of the title compound.
Following the procedure of Example 17 but using potassium hydroxide, calcium hydroxide, tetramethylammonium hydroxide, and benzyltrimethylammonium hydroxide in place of sodium hydroxide, there are obtained the corresponding salts of 16-phenoxy-17,18,19,20-tetranor-PGF 2 α.
Likewise following the procedure of Example 17 each of the 16-phenoxy (or substituted-phenoxy) PGE-type, PGF-type, PGA-type, and PGB-type acid and also their 15β-epimers and racemates defined above is transformed to the sodium, potassium, calcium, tetramethylammonium, and benzyltrimethylammonium salts. | Prostaglandin-type compounds with a phenoxy or substituted-phenoxy substituent at the C-16 position are disclosed, with processes for making them. These compounds are useful for a variety of pharmacological purposes, including anti-ulcer, inhibition of platelet aggregation, increase of nasal patency, labor inducement at term, and wound healing. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from Japanese Patent Application No. 2007-257054 filed on Oct. 1, 2007, the entire subject matter of which is incorporated herein by reference.
BACKGROUND
1. Technical Field
Features described herein relate to an image forming apparatus for forming an image on a printing medium.
2. Related Art
A color ink-jet printer is known as an imaging forming apparatus. In this printer, ink droplets are ejected sequentially to a printing medium while an ink head for ejecting plural ink droplets is moved in the main scanning direction. After a scan in the main scanning direction has finished, an auxiliary scan is performed by, for example, moving the printing medium in a direction that crosses (e.g., is perpendicular to) the main scanning direction and then a main scan is performed again.
In the ink head, discharge apertures (printing elements) for ejecting plural ink droplets are arranged in the auxiliary-scanning direction. From a main scan, these apertures eject ink droplets onto a printing medium, forming rows of plural dots arranged in the main scanning direction (sometimes referred to as “rasters”) When the printing medium is thereafter moved in the auxiliary-scanning direction by a ink head length, there may occur a phenomenon that the interval between the tail raster formed by the preceding main scan and the head raster formed by the current main scan becomes wider than the interval between rasters that are formed by one main scan due to, for example, an error of a feed mechanism for feeding the printing medium. In this case, white streaks occur which are called banding.
FIG. 6A shows example banding that occurs in the above manner. An ink head 70 is formed with 100 discharge apertures in the auxiliary-scanning direction. Dots indicated by white circles are formed by a main scan (preceding main scan) by the 97th to 100th discharge apertures of the ink head 70 .
Then, after the printing medium has been transported in the auxiliary-scanning direction, dots indicated by black circles are formed by the 1st to 4th discharge apertures of the ink head 70 . If the printing medium is transported by 101×d by the auxiliary scan (d: is the pitch of the discharge apertures of the ink-jet head 70 ), the interval between the tail raster formed by the preceding main scan and the head raster formed by the current main scan has a normal value. However, assume that the printing medium has been transported excessively (excess distance: Δ). In this case, the distance between the raster formed by the 100th discharge aperture in the preceding main scan and the raster formed by the 1st discharge aperture in the current main scan is equal to d+Δ. The raster interval there is wider than the other intervals d by Δ, which means banding.
In one known method for reducing the degree of such banding, as shown in FIG. 6B , the printing area of a preceding main scan and that of a current main scan overlap each other, so that for the rasters in the overlap area, some of the dots are printed by the preceding main scan, and the remaining dots are printed by the current main scan.
In the example of FIG. 6B , the rasters of the overlap area are formed by the 99th and 100th discharge apertures of the ink head 70 in the preceding main scan and by the 1st and 2nd discharge apertures of the ink head 70 in the current main scan.
FIG. 6C shows a case of the FIG. 6B technique, in which the printing medium was transported excessively (excess distance: Δ) in the auxiliary-scanning direction. Dots formed by the 1st discharge aperture of the ink head 70 are deviated downstream by Δ from dots formed by the 99th discharge aperture of the ink head 70 , and dots formed by the 2nd discharge aperture of the ink head 70 are deviated downstream by Δ from dots formed by the 100th discharge aperture of the ink head 70 . However, since the gaps caused by these deviations are not located on straight lines, they are less noticeable, and the degree of banding can be reduced.
However, in the technique discussed above, one raster is printed by plural main scans in an overlap printing area. Therefore, if an error occurs between a preceding main scan and a current main scan, dots formed by the preceding main scan and dots formed by the current main scan may overlap with each other. Such overlapping dots may be more noticeable to the human eye, and is unacceptable in view of increasing demand for higher print accuracy. Improving print accuracy is also hampered by the increasing demand for higher print speeds. As the movement speed in the main scanning direction is increased, the shape of the dots formed becomes less of a circle and more like an ellipse that is long in the main scanning direction.
As the printing speed is increased, the time interval between dot formation by a preceding main scan and that by a current main scan (i.e., the time from landing of ink droplets onto a printing sheet in the preceding main scan to landing of ink droplets in the current main scan) becomes shorter, and the current ink droplets land before the preceding ink droplets dry.
Therefore, if a deviation occurs in the main scanning direction, dots formed by the preceding main scan and dots formed by the current main scan may overlap with each other. When a dot of the current main scan is superimposed on a dot of the preceding main scan before the latter dries, then the two dots are combined into a single dot having a larger diameter, resulting in a deterioration in dot graininess.
FIG. 6D shows how elliptical dots formed by a preceding main scan and elliptical dots formed by a current main scan are connected to each other. If dots are connected to each other in this manner, small dots are particularly deteriorated in graininess when combined into larger dots. This means a problem that a rough, grainy image is formed instead of an intended high-resolution image.
SUMMARY
A need has arisen to provide an image forming apparatus capable of reducing the degree of banding or preventing deterioration in dot graininess.
In some embodiments, a printer may include a recording head configured to form a pattern on a recording medium; a main scanning unit configured to change a relative position between the recording head and the recording medium in a main scanning direction perpendicular to the auxiliary-scanning direction; an auxiliary-scanning unit configured to change a relative position between the recording head and the recording medium in the auxiliary-scanning direction; and a processing unit configured to control the printing head, the main scanning unit and the auxiliary-scanning unit to form rows of dots extending in the main-scanning direction and columns of dots extending in the auxiliary-scanning direction using a plurality of partially overlapping main scans, wherein in a non-overlapping area, adjacent rows and columns of dots are at uniform grid locations, and in an overlapping area, adjacent rows are offset, in the auxiliary-scanning direction, by a distance smaller than a distance between adjacent columns, wherein dots in adjacent rows appear in alternating columns, and dots in adjacent columns appear in alternating rows.
In the overlapping area, adjacent rows may be offset, in the auxiliary-scanning direction, by half the distance between adjacent columns
The change in relative position can be accomplished by, for example, moving the recording head and/or recording medium, and the overlapping scans may include three or more scans.
In some embodiments, the dots (or dot positions) may be in a grid pattern, and may include more than one dot, separated by a predetermined distance.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative aspects of the features will be described in detail with reference to the following figures wherein:
FIG. 1 is a block diagram schematically showing the electrical configuration of a printer as an image forming apparatus according to an embodiment described herein;
FIGS. 2A and 2B are schematic diagrams showing arrangements of dots formed on a printing medium; FIG. 2A shows an arrangement of dots that are formed normally and FIG. 2B shows an arrangement of dots that are formed when an error has occurred in an auxiliary scan;
FIG. 3A is a schematic diagram showing a dot arrangement in a case that the number of passes is three;
FIG. 3B is a graph showing a relationship between the number of passes and the movement distance per pass;
FIGS. 4A and 4B are schematic diagrams each showing a row interval and a column interval of dots that are formed in a high-resolution area;
FIG. 5 is a flowchart of a dot allocation process; and
FIGS. 6A-6D are schematic diagrams showing dot arrangements of conventional techniques; FIG. 6A shows a state in which banding has occurred due to an error in the transport direction, FIG. 6B is a dot arrangement diagram illustrating a conventional method for reducing the degree of banding, FIG. 6C shows how the degree of banding is reduced when an error occurs in the transport direction, and FIG. 6D shows a problem of the conventional method for reducing the degree of banding.
DETAILED DESCRIPTION
Features herein will be described in detail with reference to the accompanying drawings.
A printer 1 as an example image forming apparatus according to an embodiment will be hereinafter described with reference the accompanying drawings. FIG. 1 is a block diagram schematically showing the electrical circuit configuration of the printer 1 . The printer 1 may be an ink-jet printer, which forms a color image by ejecting inks of plural colors to a printing medium (e.g, paper).
A controller for controlling the printer 1 is equipped with a main-body-side control board 12 and a carriage board 13 . The main-body-side control board 12 may be mounted with a central processing unit (CPU) 2 , a read-only memory (ROM) 3 in which various control programs to be run by the CPU 2 and fixed value data are stored, a random access memory (RAM) 4 which may be a memory for storing various data etc. temporarily, a flash memory 5 , an image memory 7 , a gate array (G/A) 6 , etc. These various storage components may be one or more computer-readable media, storing control programs and computer-executable instructions for performing the steps described herein.
The CPU 2 as a computing device processes input image data according to a print control program 3 a that may be stored in the ROM 3 in advance, and may store resulting image data in the image memory 7 . The CPU 2 may also generate a print timing signal etc. and transfers individual signals to the gate array 6 (described later). The CPU 2 may also be connected to, and control, a variety of other components, such as an operating panel 45 through which a user makes a print instruction etc., a carriage return (CR) motor drive circuit 39 for driving a carriage motor (CR motor) 16 for moving a carriage 64 mounted with an ink head 109 in a main scanning direction which crosses (is perpendicular to) a auxiliary-scanning direction, a line feed (LF) motor drive circuit 41 for driving a transport motor (LF motor) 40 for driving a transport roller 101 which transports a printing medium in the auxiliary-scanning direction, a paper sensor 106 , a linear encoder 43 , and a rotary encoder 46 .
Various data are temporarily stored in the RAM 4 when the CPU 2 runs the print control program 3 a . The paper sensor 106 is a sensor for detecting presence/absence of a printing sheet. The linear encoder 43 is a device for detecting a movement distance of the carriage 64 . The reciprocation movement of the carriage 64 in the main scanning direction is controlled according to the movement distance detected by the linear encoder 43 . The rotary encoder 46 is a device for detecting a rotation angle of the transport roller 101 . The transport roller 101 is controlled according to the rotation angle detected by the rotary encoder 46 .
A print control program 3 a for performing print processing, a dot allocation program 3 b for performing processing of allocating dot positions to reduce the degree of banding, and other programs may be stored in the ROM 3 . Correction values to be used for transporting a printing sheet correctly and scanning the ink head 109 correctly and other values may be determined by a pre-shipment test and stored in the flash memory 5 . The CPU 2 , the ROM 3 , the RAM 4 , the flash memory 5 , and the gate array 6 are connected to each other via a bus line 47 .
The gate array 6 transfers print data (drive signals) for printing, on a printing sheet, of image data stored in the image memory 7 and such signals as a transfer clock that are synchronized with the print data to the carriage board 13 on the basis of a timing signal transferred from the CPU 2 and the image data stored in the image memory 7 . Furthermore, the gate array 6 stores, in the image memory 7 , image data that is transferred from a personal computer, a digital camera, or the like via an interface (I/F) 44 such as a universal serial bus (USB) interface.
The carriage board 13 serves to apply voltages to piezoelectric actuators of the ink head 109 . As a result of this action, ink droplets are ejected from the ink head 109 toward a printing medium.
Next, an arrangement of dots (or dots at dot positions) that are formed on a printing sheet by the printer 1 will be described with reference to FIGS. 2A and 2B . Like FIGS. 6A-6D , FIGS. 2A and 2B are schematic diagrams showing ink-ejecting discharge apertures of the ink head 109 and arrangements of dots that are formed on a printing medium by the discharge apertures. In this example, the ink head 109 is formed with a print height having 100 discharge apertures (indicated by hatched circles) in the auxiliary-scanning direction. The illustrated discharge apertures are assigned numbers 1 to 100 (the head discharge aperture is given the number 1). Dots formed on a printing sheet by a preceding main scan are indicated by white circles, and dots formed on the printing sheet by a current main scan are indicated by black circles.
Dots are located at lattice positions, arranged at equal positions vertically (in FIG. 2A , along the auxiliary-scanning direction) in columns, and horizontally (in FIG. 2A , along the main-scanning direction) in rows, or rasters. As illustrated, the columns are assigned columns numbers 1 , 2 , . . . from the left end of a page and, likewise, the rows are assigned row numbers 1 , 2 , . . . from the head of the page.
In part of an area on a printing sheet where printing was performed by a preceding main scan, rasters are formed by a current main scan at different rows from the positions of the rasters formed by the preceding main scan, whereby that part of the area is given a high resolution. In other areas, printing is performed at a low resolution. An example printing method is as follows. In a preceding main scan, rasters are formed at alternate row positions. In the next main scan (the current main scan), in an area where printing should be performed at the high resolution, rasters are formed at rows that are located between the rows of the rasters that were formed by the preceding main scan. As a result, the resolution in the auxiliary-scanning direction in the high-resolution area is two times that in non-overlap areas.
In FIGS. 2A and 2B , dots that are formed by a preceding main scan performed in a head portion of a page, and dots that are formed by the next main scan (current main scan) are shown aligned with the discharge apertures of the ink head 109 at the time the dots were formed.
FIG. 2A shows a dot arrangement that is formed when no transport error has occurred in the auxiliary-scanning direction. FIG. 2B shows a dot arrangement that is formed when a transport error Δ has occurred in the auxiliary-scanning direction.
As shown in FIG. 2A , in the preceding main scan, dots are formed at each column (1st column, 2nd column, 3rd column, . . . ) at the 193rd row by the 97th discharge aperture. Although omitted in FIG. 2A , the odd-numbered rows from the 1 st to the 191 st rows also have the same dot positions as row 193 .
Dots are formed at the odd-numbered columns (1st column, 3rd column, 5th column, . . . ) at the 195th, 197th, and 199th rows by the 98th, 99th, and 100th discharge apertures. The interval between these rows is equal to d.
Then, in the current main scan, dots are formed at the even numbered columns (2nd column, 4th column, 6th column, . . . ) are formed at the 196th, 198th, and 200th rows by the 1st, 2nd, and 3rd discharge apertures, respectively.
In this manner, the dots are arranged in checkered form in the high-resolution area, and the interval between the rasters formed in the area from the 195th row to the 200th row is equal to a half (d/2) of the interval d between the rasters formed in the area from the 1st row to the 195th row.
Therefore, a subset of the rasters formed by the current main scan are formed in an area in which other rasters were formed by the preceding main scan. Accordingly, in those areas, the resolution in the auxiliary-scanning direction becomes two times higher than that of other areas. Even if a transport error occurs, the raster interval does not exceed d, and hence the degree of banding can be reduced. Furthermore, even if an error occurs in the main scanning direction, dots are formed in a different position in the auxiliary-scanning direction by the current main scan than by the preceding main scan and hence dots are less prone to overlap with each other. This can prevent deterioration of the dot graininess.
FIG. 2B shows dots that are formed when a printing sheet was transported excessively (excess distance: Δ) in the auxiliary-scanning direction after a preceding main scan and then a current main scan was performed.
The interval between a raster formed at the 195th row (formed by the 98th discharge aperture in the preceding main scan) and a raster formed at the 196th row (formed by the 1st discharge aperture in the current main scan) becomes d/2+Δ, and the interval between a raster formed at the 197th row (formed by the 99th discharge aperture in the preceding main scan) and the raster formed at the 196th row (formed by the 1st discharge aperture in the current main scan) becomes d/2−Δ. Likewise, the interval between the raster formed at the 197th row (formed by the 99th discharge aperture in the preceding main scan) and a raster formed at the 198th row (formed by the 2nd discharge aperture in the current main scan) becomes d/2+Δ, and the interval between a raster formed at the 199th row (formed by the 100th discharge aperture in the preceding main scan) and the raster formed at the 198th row (formed by the 2nd discharge aperture in the current main scan) becomes d/2−Δ. In this manner, blank lines having a width d/2+Δ are formed when a deviation of Δ occurs in the auxiliary-scanning direction. However, since the width of the blank lines does not exceed d, the degree of banding can be reduced.
In addition to reducing the degree of banding and minimizing deterioration of the graininess due to overlap of dots, increasing the printing speed is required. As described above, the degree of banding is reduced by forming rasters by a current main scan in part of an area that was formed by a preceding main scan. The effect of reducing the degree of banding is higher as the resolution in the auxiliary-scanning is set higher in that part of the area. However, there is a problem that as the resolution is set higher, the number of main scans (passes) is increased and the printing speed is lowered.
FIG. 3A is a schematic diagram showing dots that are formed in a high-resolution area and its neighborhood in a case that the number of passes is three. As in the example of FIG. 2A , it is assumed that the ink head 109 is formed with 100 discharge apertures (indicated by hatched circles) in the auxiliary-scanning direction. The discharge apertures are assigned numbers 1 to 100 (the head discharge aperture is given the number 1). Dots formed on a printing sheet by a first main scan are indicated by white circles, dots formed by a second main scan are indicated by black circles, and dots formed by a third main scan are indicated by double circles.
As shown in FIG. 3A , the interval between rasters formed in the high-resolution area is ⅓ of the interval between rasters formed in non-overlap areas (the resolution is tripled). Therefore, rasters formed by one main scan are given row numbers that are separated from each other by three in order from the head of a page (e.g., 1, 4, 7, . . . ). With this notation, as shown in FIG. 3A , in the first main scan illustrated, a raster is formed at the 286th row by the 96th discharger aperture and a raster is formed at the 289th row by the 97th discharge aperture. In each of these rasters, dots are formed at all columns as needed by the image.
Rasters are also formed at the 292nd, 295th, and 298th rows by the 98th, 99th, and 100th discharge apertures, respectively, during that first main scan. However, in each of these rasters, dots are formed at alternate columns (e.g., row 292 has dots in the odd-numbered columns, while row 295 has dots in the even-numbered columns).
After the first main scan, the printing sheet is transported in the auxiliary-scanning direction. In this example, the ink head 109 is transported by (97+⅓) times the interval between the discharge apertures in the auxiliary-scanning direction. In the next main scan (second pass), rasters are formed at the 293rd, 296th, and 299th rows by the 1st, 2nd, and 3rd discharge apertures, respectively. In those rows, dots may be formed at alternating columns (e.g., row 293 has dots in the even-numbered columns, while row 296 has them in the odd-numbered columns), and alternating with those from the first pass (e.g. the first row in the first pass had dots on the odd-numbered columns, while the first row in the second pass had dots on the even-numbered columns).
Then, the printing sheet is transported by ⅓ times the interval between the discharge apertures in the auxiliary-scanning direction. In the next main scan (third pass), rasters are formed at the 294th, 297th, and 300th rows by the 1st, 2nd, and 3rd discharge apertures, respectively. As shown in FIG. 3A , in the area from the 292nd row to the 300th row, dots are also formed in checkered form (e.g., row 294 has dots in the odd-numbered columns, while row 297 has dots in the even-numbered columns).
In the example of FIG. 3A , the first transport is performed so that the 1st discharge aperture of the ink head 109 will be located at the 293rd row to begin the second pass. However, in the first transport, the ink head 109 may be transported to any position as long as the ink head 109 is allowed to form rasters at the 293rd row to the 299th row. Furthermore, in the example of FIG. 3A , dots are formed by the 1st to 3rd discharge apertures in the second main scan, but other apertures may be used instead. In the second main scan, the 4th to 100th discharge apertures may either form or not form dots.
FIG. 3B is a graph showing a relationship between the printing speed and the resolution (number of passes) in a high-resolution area. In this graph, the horizontal axis represents the number of passes and the vertical axis represents the (average) movement distance per pass. The example ink head 109 is formed with 100 discharge apertures in the auxiliary-scanning direction, and the movement distance is expressed in the number of discharge apertures in the auxiliary-scanning direction. This graph corresponds to a case that a high-resolution area includes an area that is formed by the 96th to 100th discharge apertures in the first main scan (the high-resolution area ratio is 5%).
In a conventional printing operation in which no high-resolution areas are formed, the number of passes is one and for each path the ink head 109 is moved (actually, a printing sheet is moved) in the auxiliary-scanning direction by a distance corresponding to the 100 discharge apertures. Where the number of passes is two in the embodiment, as shown in FIG. 2A , in a high-resolution area, rasters are formed by a current main scan between rasters that were formed by a preceding main scan. In this case, for each pass, the ink head 109 is moved in the auxiliary-scanning direction by 95% of the head length.
Where the number of passes is three, in a high-resolution area, the section (length: d) between each adjoining pair of rasters that were formed by a first main scan is divided into three equal parts. In a second main scan, a raster is formed at a ⅓ position of the section. In a third main scan, a raster is formed at a ⅔ position of the section. In the example of FIG. 3A , the distance of the first auxiliary scan is 95% of the head length plus d/3 and that of the second auxiliary scan is d/3. Therefore, the average head movement distance is approximately equal to (95/2) % of the head length.
Likewise, where the number of passes is four, the average head movement distance is approximately equal to (95/3) % of the head length. That is, the movement distance per pass is given by (N−M)/(P−1), where N is the number of discharge apertures of the ink head 109 which are arranged in the auxiliary-scanning direction, M is the number of discharge apertures corresponding to a high-resolution area among the N discharge apertures, and P is the number of passes.
As is apparent from this graph, setting the number of passes to three or more makes the movement distance per pass much shorter than in the case where the number of passes is two. A shorter movement distance per pass means a lower printing speed. Therefore, to maintain a higher printing speed, the number of passes is set small to enable high-speed printing and the resolution of a high-resolution area is set to two times that of a low-resolution area.
Next, a detailed dot arrangement in a case that the number of passes is two will be described with reference to FIG. 4 . As described above, a transport error may occur when a printing sheet is transported in the auxiliary-scanning direction, and an error may occur in the main scanning direction when the ink head 109 is moved in the main scanning direction.
Factors that relate to an error in the dot landing position in the auxiliary-scanning direction include the accuracy of transport of a printing sheet in the auxiliary-scanning direction and the working accuracy that determines the interval between the discharge apertures in the auxiliary-scanning direction and the directions of the discharge apertures. On the other hand, factors that relate to an error in the dot landing position in the main scanning direction include the accuracy of reciprocation of the ink head 109 , the working accuracy that determines the interval between the discharge apertures in the main scanning direction and the directions of the discharge apertures, and the timing and ejecting speed of the ink ejecting which is performed while the ink head 109 is moved. In particular, since ink droplets are ejected while the ink head 109 is moved at high speed, the shape of dots formed on a printing sheet tends to be an ellipse that is longer in the main scanning direction rather than a circle. Therefore, in an overlap printing area, dots tend to overlap with each other more in the main scanning direction than in the auxiliary-scanning direction.
FIG. 4A is a schematic diagram showing an arrangement of dots that are formed in a high-resolution area, such as in FIG. 2A . Dots that formed at the 1st and 3rd columns at the 195th and 197th rows by a preceding main scan and a dot formed at the 2nd column at the 196th row by a current main scan are shown. The interval between the columns is represented by A and the interval between the rows is represented by B.
As mentioned above, there are more factors that influence an error in the main scanning direction than factors that influence an error in the auxiliary-scanning direction. In the main scanning direction, since ink droplets are ejected while the ink head 109 is moved at high speed, the shape of dots formed on a printing sheet becomes an ellipse that is longer in the main scanning direction rather than a circle. In view of this, the interval A between the columns is set longer than the interval B between the rows. This makes it possible to lower the probability that dots that are formed by a current main scan overlap with dots that were formed by a preceding main scan. Since the interval between dots formed at each row is 2×A, the interval between dots formed in the main scanning direction can be set longer than two times the interval B between the rows in the auxiliary-scanning direction.
In the discussion above, the examples given show a single dot being formed at the various dot positions in the uniform grid pattern formed by the recording head in a main scan. The dot positions can, however, have more than one dot at each position. FIG. 4B is a schematic diagram showing another arrangement of dots that are formed in a high-resolution area. In the example of FIG. 4B , the row has two dots, then two blanks, then two dots, and so on. Stated differently, it is divided into sections each having two columns, and two dots are formed in every other section. At the next row, dot-forming sections and dot-non-forming sections are located at opposite positions to the positions at the one row. That is, dots are not formed in a section having a dot-forming section immediately above and dots are formed in a section having a dot-non-forming section immediately above. For example, at the 195th row, dots are formed at the 1st and 2nd columns, not formed at the 3rd and 4th columns, and formed at the 5th and 6th columns. At the next, 196th row, dots are not formed at the 1st and 2nd columns, formed at the 3rd and 4th columns, and not formed at the 5th and 6th columns. Likewise, at the 197th row, dots are formed at the 1st and 2nd columns, not formed at the 3rd and 4th columns, and formed at the 5th and 6th columns.
Even with this arrangement, dots are more prone to overlap with each other in the main scanning direction than in the auxiliary-scanning direction. Therefore, the column interval A can be set longer than the row interval B. The row interval B is controlled by a signal that is supplied to the LF motor drive circuit 41 which controls the LF motor 40 . The column interval A is controlled by a signal that is supplied to the CR motor drive circuit 39 which controls the CR motor 16 . These signals are supplied from the CPU 2 .
Next, a dot allocation process that can be executed by the CPU 2 will be described with reference to FIG. 5 . FIG. 5 is a flowchart of a dot allocation process for allocating dots in the arrangement form of FIG. 2A . In this dot allocation process, i is a variable that indicates a dot as an element of a raster, j is a variable that indicates a row (raster), N represents the number of discharge apertures of the ink head 109 which are arranged in the auxiliary-scanning direction, and M represents the number of discharge apertures for forming a high-resolution area among the N discharge apertures.
When a head portion of a printing sheet is subjected to a main scan, dots are formed at all the columns at the odd-numbered rows of the 1st to (2N−2M−1)th rows by the 1st to (N−M)th discharge apertures. And dots are formed at the even-numbered columns at the odd-numbered rows of the (2N−2M)th to (2N−1)th rows by the (N−M+1)th to Nth discharge apertures. Then, the printing sheet is transported by an auxiliary scan so that the 1st discharge aperture will be located at the (2N−2M+2)th row. Then, dots are formed at the odd-numbered columns at the even-numbered rows of the (2N−2M+2)th to 2Nth rows by the 1st to Mth discharge apertures. In this manner, a low-resolution area is formed from the 1st row to the (2N−2M)th row and a high-resolution area where dots are arranged in checkered form is formed from the (2N−2M)th row to the 2Nth row. Subsequently, an auxiliary scan and a main scan are performed repeatedly, whereby low-resolution areas and high-resolution areas are formed.
The dot allocation process is a process for sequentially allocating dot data at positions on a printing sheet that are indicated by pairs of a row and a column. First, at step S 1 , variable i which indicates a column is set at 0 and variable j which indicates a row (raster) is set at 1. At step S 2 , a remainder E of division of variable j by the auxiliary-scanning amount (2N−2M+1) is calculated (“%” is an operator of this operation). If it is judged at step S 3 that variable j is larger than 2M (S 3 : yes), the row concerned does not belong to a high-resolution portion of the page. If it is judged at step S 4 that the remainder E is smaller than or equal to 2M (S 4 : yes), the area concerned is a high-resolution area. At step S 5 , an allocation mask to be applied to 8-bit dot data of rasters whose remainders E are odd numbers is set at 0x55 (“0x” means a hexadecimal number; this also applies to the following description) and an allocation mask to be applied to 8-bit dot data of rasters whose remainders E are even numbers is set at 0xAA.
On the other hand, if variable j is smaller than or equal to 2M (S 3 : no), the row concerned belongs to a head portion of the page and hence printing should be performed at a low resolution. Also, if the remainder E is larger than 2M (S 4 : no), the row concerned belongs to an area where printing should be performed at the low resolution. Therefore, in these cases, at step S 6 the allocation mask to be applied to 8-bit dot data of rasters whose remainders E are odd numbers is set at 0xFF and the allocation mask to be applied to 8-bit dot data of rasters whose remainders E are even numbers is set at 0x00.
When step S 5 or S 6 has been executed, at step S 7 the 8-bit dot data is multiplied by the thus-set allocation masks and resulting dot data are stored in the image memory 7 . At step S 8 , it is judged whether variable i indicates the last dot of the raster. If there remains an unprocessed dot(s) (S 8 : no), variable i is incremented by 8 at step S 9 and the process returns to step S 7 to read the next 8-bit data to be used for forming the raster. If variable i indicates the last dot of the raster (S 8 : yes), it is judged at step S 10 whether variable j indicates the last raster of the page. If variable j does not indicate the last raster of the page (S 10 : no), variable j is incremented by 1 at step S 11 , variable i is set to 0 at step S 12 , and the process returns to step S 2 to perform processing for the next row. If variable j indicates the last raster of the page (S 10 : yes), which means that processing for all rasters of the page has completed, the dot allocation process is finished.
As described above, in the embodiment, in an overlap area of an area that was formed by a preceding main scan and an area that is formed by a current main scan, dots formed by the current main scan are deviated from dots formed by the preceding main scan in the recording sheet transport direction (auxiliary-scanning direction) and the dots are arranged in checkered form as a whole. This makes it possible to reduce the degree of banding because no straight blank lines are formed even if an error occurs in the transport direction. Furthermore, there are more factors that influence an error in the main scanning direction than factors that influence an error in the auxiliary-scanning direction. Since dots are formed while the ink head 109 is moved in the main scanning direction, the dots assume an elliptical shape that is longer in the main scanning direction. Therefore, the probability that dots that are formed by a current main scan overlap with dots that were formed by a preceding main scan is higher in the main scanning direction than in the auxiliary-scanning direction. However, the dots are prevented from overlapping with each other because the column interval A is set longer than the row interval B. Therefore, the dot graininess is not deteriorated.
Although the features above have been described by means of the embodiment, this patent is not limited to the above embodiment, and various improvements and modifications are possible without departing from the spirit and scope of the disclosure herein.
For example, although the above embodiment is directed to the process of the printer 1 , the embodiment can also be applied to a process of a multifunction peripheral apparatus, a facsimile apparatus, or the like.
Although in the above embodiment the printing medium on which printing is performed is a printing sheet (paper), the printing medium is not limited to paper and may be a cloth, a vinyl member, or the like.
In the examples of FIGS. 4A and 4B , in a high-resolution area, the line at each row is divided into equal sections each having a fixed number of (one or two) columns (e.g., equal numbers of blanks and dots within a row). Alternatively, the line at each row may be divided into sections having irregular numbers of columns in such a manner that, for example, dots are formed at two adjoining columns and dots are not formed at next three adjoining columns.
While the various aspects of the disclosure have been described in conjunction with the illustrative embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents may become apparent to those having at least ordinary skill in the art. Accordingly, the illustrative embodiments of the disclosure, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to embrace all known or later developed alternatives, modifications, variations, improvements and/or substantial equivalents. | An image forming apparatus includes a recording head including a plurality of printing elements each of which offsets at least in a auxiliary-scanning direction one another and ejects droplets toward a recording medium. The image forming apparatus further includes a main scanning unit configured to scan the recording head, relative to the recording medium, in a main scanning direction perpendicular to the auxiliary-scanning direction. The image forming apparatus still further includes a auxiliary-scanning unit configured to scan the recording head, relative to the recording medium, in a main scanning direction perpendicular to the auxiliary-scanning direction. The image forming apparatus still yet further includes a controller configured to control the printing head, the main scanning unit and the auxiliary-scanning unit to form dots in rows arranged in the auxiliary-scanning direction at a first predetermined interval, and columns arranged in the main scanning direction at a second predetermined interval while performing main scans and sub-scans repeatedly. The controller controls the printing head, the main scanning unit and the auxiliary-scanning unit to form first dots in an area of the printing medium at first alternate columns by a first main scan, and to form second dots in the area by a second main scan at second alternate columns different from the first alternate columns. The second dots are shifted, relative to the first dots, a first predetermined distance smaller the first predetermined interval. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to the removal of burrs at the exit end of drilled holes, especially in manufactured metal parts, and more particularly to a method of using a high power laser beam to remove burrs at the exit end of such holes.
In the manufacture of machinery of various kinds it is often necessary to provide intersecting passageways in various metal parts thereof. Often, one of such passageways will receive a plunger or shaft and the passageway intersecting therewith will provide for the flow of lubricating oil or other fluid thereto.
In any event, such intersecting passageways are usually formed by forming a passageway into the manufactured metal part and subsequently drilling a hole into the metal part which intersects the passageway. It is a well-known fact that when a hole is drilled through a surface of a metal part, a thin protruding rough rim or edge will be formed about the hole in such surface due to the fact that a portion of the drill will tend to exit from the metal part extruding some small amount of incompletely cut metal from the hole in the process. Such a thin protruding rim or edge is known as a "burr" and will tend to be formed at the junction of a drilled hole with a previously formed passageway in a metal part.
It is, of course, necessary to remove any such burrs from the interior of the passageway, since such burrs will change the internal dimensions thereof and interfere with the passage of fluids, shafts or plungers through the passageway which may be a first drilled hole. In the prior art, various time consuming and expensive mechanical methods have been used to remove such burrs. For example, where the passageway is formed by a first drilled hole, the drill may be passed into it a second time or other special tools may be used within the passageway to mechanically remove the burrs. There is, of course, the danger that the material which forms the burr in the passageway will not be removed but simply forced into a different burr inside the end of the drilled hole, as well as the danger that the internal dimensions of the passageway will be spoiled by misalignment of the drill or other tool therewith. If the material which forms the burr is not removed but simply relocated, then there is the danger that some or all of such material will subsequently break away and cause damage somewhere else in the machine.
It is the basic object of this invention to provide a method for quickly and efficiently removing burrs from the junction of drilled holes with a surface or passageway in metal parts, which method will result in the complete removal of material which forms such burrs without danger of spoiling the surface or the internal dimensions of the passageway or drilled holes.
SUMMARY OF THE INVENTION
Briefly, the burr produced at the junction of a drilled hole in a metal part with a passageway previously formed in the metal part and extending along an axis from an opening to the outside thereof is removed according to this invention by producing a high power beam of coherent electromagnetic energy which is focused to a maximum cross-sectional diameter in the focal plane thereof smaller than the minimum cross-sectional dimension of such passageway. The focal plane of the beam is positioned substantially normal to the axis of the passageway and is located with respect to the opening of the passageway so that all of the beam will enter the passageway. The axis of the beam is positioned with respect to the axis of the passageway so that a peripheral portion only of the beam downstream from the focal plane thereof impinges the burr at the junction of the drilled hole with the passageway.
DESCRIPTION OF THE DRAWING
The foregoing and other objects and features of this invention will be more fully apparent from a reading of the following detailed description of the method of this invention in conjunction with the drawing wherein:
FIG. 1 is a side view in elevation of a crank shaft having intersecting drilled holes or passageways therein as indicated by dotted lines to which the method of this invention may be applied with advantage;
FIG. 2 is an enlarged fragmentary cross-sectional view of a metal part showing the metal burr formed at the junction between a drilled hole and another passageway therein with a laser and a focused beam of coherent electromagnetic energy schematically represented in operational position with respect to the metal part for the removal of the burr in accordance with the teaching of this invention;
FIG. 3 is a fragmentary cross-sectional view taken along line 3--3 of FIG. 2 with the beam of coherent electromagnetic energy indicated schematically in operative relation to the burr;
FIG. 4 is a fragmentary cross-sectional view taken along line 4--4 of FIG. 2 with the beam of coherent electromagnetic energy represented schematically; and
FIG. 5 is a fragmentary cross-sectional view of a metal part similar to FIG. 2 but showing a plurality of drilled holes intersecting a passageway therein.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a manufactured metal part 10 for a machine to which the teaching of this invention may be applied with advantage, is shown in side elevation. The metal part 10 is a steel forging in the form of a crankshaft for a diesel engine and includes a number of intersecting passageways or oil holes indicated by dotted lines 12. To provide a frame of reference, the crankshaft has a length of about 30 inches and a maximum diameter of about 8 inches. The intersecting oil holes indicated by dotted lines 12 have a diameter of about 1/2 inch and are drilled into the crankshaft after it is forged and ground. The intersections of the oil holes must be free of chips and burrs and the crankshaft must pass a number of other stringent inspections before it can be assembled with other parts into a diesel engine.
As is well known, whenever a hole is drilled in a metal part, which intersects a passageway such as another drilled hole in the part, a thin protruding rough rim or edge called a "burr" will be formed at the junction between the drilled hole and the passageway. Referring to FIG. 2, a manufactured metal part such as the crankshaft of FIG. 1 is shown in fragmentary cross-section with a passageway 22 formed therein and extending along an axis from an opening to the outside of the metal part 20. The passageway 22 may be formed by drilling a hole into the metal part 20, for example. In any event, a subsequently drilled hole 24 is shown intersecting the passageway 22. As indicated in idealized form in FIG. 2, the subsequent drilling of the intersecting hole 24 produces a thin projecting rim edge or burr about the hole 24 at the junction thereof with the passageway 22. This is the burr which must be removed before the metal part 20 can be incorporated into a machine.
According to the teaching of this invention, such burr is removed through the use of a high power laser 30 shown schematically in FIG. 2. The laser 30 includes a focusing means 32 by which the beam (indicated by dash lines 34) of coherent electromagnetic energy produced by the laser is focused to a maximum cross-sectional diameter in the focal plane 36 thereof which is smaller than the minimum cross-sectional dimension of the passageway 22. The laser 30 and focusing means 32 are positioned with respect to the passageway 22 so that the focal plane 36 of the focused beam is substantially normal to the axis of the passageway 22. As shown in FIG. 2, the focal plane 36 of the beam 34 is located within the passageway 22, however it is only necessary according to the teaching of this invention that the focal plane be properly located so that all of the beam 34 will enter the passageway with none of the beam 34 impinging on the exterior of the metal part 20 about the opening of the passageway 22.
The focal length of the focusing means 32 should be comparatively short with respect to the length of the passageway 22 so that the beam 34 will diverge within the passageway 22 from its focal plane 36. According to the teaching of this invention, the focal plane 36 of the beam 34 must be located between the laser 30 including the focusing means 32 and the junction between the drilled hole 24 and passageway 22. In addition, according to the teaching of this invention, the axis of the beam 34 must be positioned with respect to the axis of the passageway 22 so that a peripheral portion only of the beam 34 downstream from the focal plane 36 impinges upon the burr 26 formed at the junction between the drilled hole 24 and the passageway 22.
Referring to FIG. 3, the impingement of a peripheral portion of the diverging beam 34 on the burr 26 formed at the junction between the drilled hole 24 and the passageway 22 in the metal part 20 is shown. Since the burr 26 is thin and projects from the metal part 20 into the passageway 22, it will be heated rapidly to a very high temperature by the energy of the beam 34. Due to the poor heat conducting capability of thin projecting metallic elements, the burr 26 will be heated to a temperature high enough to cause it to vaporize by the impingement of the beam 34 thereon.
However, as shown in FIGS. 2 and 4, the energy of the diverging beam 34 will tend to be distributed along and about the wall of the passageway 22 downstream of the burr 26. Due to the distribution of such energy over a large area and the good heat conducting capability of the metal part 20 at the walls of the passageway 22, the temperature rise at such walls due to the absorption of the energy from the beam will be small. In any event, the energy of the beam 34 and the heating produced thereby will be sufficiently distributed along the walls of the passageway 22 and conducted therefrom into the metal part 20 to prevent any temperature effects whatever at such walls of the passageway 22.
Referring to FIG. 5, the same metal part 20 and passageway 22 are shown in fragmentary cross-section. However, in addition to the drilled hole 24, two additional drilled holes 23 and 25 are shown intersecting the passageway 22 at different points along the axis thereof. According to this invention the relative positioning of the laser 30 and focusing means 32 with respect to the opening of the passageway 22 is readily adjustable. Thus, in order to remove the burr 27 at the junction between the drilled hole 23 and the passageway 22, the spacing between the laser 30 and the opening of the passageway 22 may be increased to move the focal plane 36 of the beam closer to such opening. At the same time, the laser 30 may be shifted upwardly as shown in full in FIG. 5, with respect to the opening of the passageway 22 thereby enabling a peripheral portion only of the beam to impinge upon the burr 27. The diverging portion of the beam will, of course, be distributed along the upper portion of the remainder of the passageway 22 as described hereinabove.
Similarly, in order to remove the burr 29 at the junction between the drilled hole 25 and passageway 22, the spacing between the laser 30' and the opening of the passageway 22 may be increased and the laser shifted downwardly as shown in phantom in FIG. 5 with respect to the opening of the passageway 22. This will enable a peripheral portion only of the beam to impinge upon the burr 29 with the remainder of the diverging beam being distributed along the lower portion of the passageway 22.
In addition, the power of the focusing means 32 may be made adjustable so that the distance between such focusing means and the focal plane of the beam may be adjusted. Furthermore, it would be possible, according to this invention, to provide for a limited angular movement of the axis of the beam with respect to the axis of the passageway 22. In other words, provision may be made for tilting the focal plane of the beam a few degrees away from absolute normal in any direction in order to obtain optimum impingement of a peripheral portion of the beam on a particular burr.
It has been found that the method of this invention will not only remove the burrs at the junction between a passageway and an intersecting drilled hole but will also provide highly desirable smoothly rounded corners at such junctions. Since the burrs are vaporized by the action of the laser beam thereon, there is little danger of the presence of undetected chips of such burrs remaining in the metal part 20 after the deburring operation. Also, there is little danger of spoiling the internal dimensions of the passageway 22 during the deburring operation due to the inherent distribution of the energy of the laser beam along the walls of the passageway 22 and the excellent heat sink properties of the metal part 20 at the walls of such passageway.
It is believed that those skilled in the art will find many applications for the teaching of this invention. Various obvious steps could, of course, be added to the method taught hereinabove in order to adapt such method for a specific application. For example, light guide devices comprising articulated assemblies of mirror or lens holding and rotating tubes are known which could be used to facilitate the manual control and application of the laser beam to a complicated metal part such as the crankshaft of FIG. 1 in accordance with the teaching of this invention while allowing both the metal part and the laser to remain stationary.
In an actual reduction to practice of the method of this invention, a CO 2 laser capable of producing a coherent beam of electromagnetic energy having a wavelength of 10.6 micrometers at a power output between about 1000 watts and about 3000 watts was used to deburr a crankshaft substantially as shown in FIG. 1. The time required to complete the deburring operation according to this invention, was comparable, although not optimized, to that required for conventional deburring operations. The complete removal of the burrs and rounding of the corners at the junction of the passageways was produced and no spoilage of the passageways resulted even though the deburring operation according to this invention as practiced was not optimized. As used herein, the term "high power" laser beam means a laser beam at a power level in excess of about 100 watts. | A method of removing the burrs at the junction of a drilled hole with a passageway previously formed in a metal part by means of a high power laser beam is disclosed. Novel steps in the control of the laser beam to avoid damage to the walls of the passageway or intersecting drilled hole are described. | 1 |
TECHNICAL FIELD
The present invention relates to a method and apparatus for processing a signal. More specifically, the present invention relates to processing a signal to detect the occurrence of an external event.
BACKGROUND
Detection devices determine when a particular event occurs. Examples of detection devices include beam sensors such as those used in automatic doors. The beam sensor determines when a person has approached the door by detecting when the beam has been reflected or broken. Once the person is detected by the sensor, the door is automatically opened for the user. Other examples include label sensors. Label sensors detect labels as they pass by the sensor on a web. The detection of the label allows proper high-speed counting of labels as well as proper removal of the labels from the web.
Conventionally, the electronics of such detection devices require a user to make threshold adjustments. This adjustment is necessary due to variations in the sensing conditions. In the label sensor example, web flutter and label inconsistencies create noise in the signal. A threshold must be properly chosen to distinguish a rising or falling label edge signal from the noise. Because the web flutter and label inconsistencies change from one web to the next, the threshold must be adjusted by the user each time a new web is analyzed to produce accurate results.
Also, the electronics of detection devices require a user to make offset adjustments. An offset adjustment maintains a baseline amplified signal at a desired midway point between two sensing thresholds, one for a falling signal and one for a rising signal. These rising and falling signals represent transitions created by an external event. For instance, when a leading label edge is sensed the signal rises to a level indicating the label is present. When a trailing label edge is sensed the signal falls to a level indicating the label is not present. The signal must rise beyond a rising threshold to indicate that a leading label edge has been sensed, and the signal must fall below a falling threshold to indicate a trailing label edge has been sensed.
Amplifiers are used in the detection device to scale the detection signal to useful levels, and these amplifiers are susceptible to fluctuations in performance and calibration due to humidity, ambient temperature, and other factors. The fluctuations affect the level of the baseline signal which then affects the reliability of the detection since the baseline signal may stray too far from a threshold for a rise or fall to be properly detected. A user must continuously monitor and adjust the baseline signal to ensure that it remains midway between the two threshold levels.
Furthermore, external events may occur randomly with no consistency, and detection of these event is often done in a noisy environment. Determining the occurrence of such events is difficult because the noise can produce false detections. Furthermore, accurate detection of randomly occurring events is difficult because resulting detection signals may range from nearly DC to very high frequencies, thus rendering differentiation schemes optimized for a given frequency range virtually inoperable.
Detection sensors would be more effective if no user adjustments were necessary due to variations in the environment including noise, ambient conditions, and the disparity of event frequency. Eliminating the user threshold adjustment and/or user offset adjustment improves the ease of use of the sensor as well as the reliability of the results it produces. Similarly, providing a system that can differentiate between detection signals spanning from DC to a much higher frequency further improves the ease of use and reliability of the sensor.
SUMMARY
The present invention addresses these problems by removing the need of the user to adjust the system to optimize the threshold level and the offset of the amplifier based on the sensing conditions and the particular characteristics of the event being detected. Furthermore, the present invention addresses the problem of accurately detecting events with widely varying durations in noisy environments.
The invention is embodied in apparatuses and methods for detecting a change in a signal having a level that fluctuates in response to the external event. The apparatus includes an adjustable amplifier module for generating an amplified signal and having a signal input and an offset input. The signal input of the amplifier module is electrically connected to the signal to be detected. An offset adjusting module may be included to continually adjust the offset voltage of the adjustable amplifier module by generating an offset signal based upon the amplified signal to maintain an observed median value of the observed range for the amplified signals between a minimum and a maximum observed value. The offset signal is coupled to the offset input of the adjustable amplifier module.
The apparatus may also include a cascaded difference filter module for receiving the amplified signal to detect an occurrence of the external event by detecting when the amplified signal changes to a value greater than a threshold value. The cascaded difference filter quantifies the change in signal over multiple time intervals. A threshold adjusting module may also be included to continually adjust the threshold value based upon the amplified signal to maintain the threshold value at a desired percentage of a maximum range of observed amplified signals.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a label web, sensor unit, and associated processing module.
FIG. 2 shows the sensor unit's electrode configuration.
FIG. 3 depicts the sensor and shield capacitances.
FIG. 4 illustrates the sensor unit's electronics.
FIG. 5 is an electrical block diagram of the sensor unit and the processing module.
FIG. 6 illustrates the operational flow for the data acquisition and automatic adjustment processes.
FIG. 7 a shows the operational flow of the data acquisition process in greater detail.
FIG. 7 b depicts the operational flow of the automatic adjustment process in greater detail.
FIG. 8 illustrates the operational flow of the automatic threshold adjustment process.
FIG. 9 shows the operational flow of the automatic offset adjustment process.
FIG. 10 shows the label detection signal with and without noise and also shows the ideal digital output signal that results.
FIG. 11 illustrates the frequency passband characteristics for a 1× difference filter.
FIG. 12 depicts the input waveform of a label sensor and the resulting output waveform after application of the 1× difference filter.
FIG. 13 depicts the frequency passband characteristics for a 4× difference filter.
FIG. 14 shows the input waveform of a label sensor and the resulting output waveform after application of the 4× difference filter.
FIG. 15 illustrates the frequency passband characteristics of a 4× difference filter using averaging
FIG. 16 the input waveform of a label sensor and the resulting output waveform after application of the 4× difference filter using averaging.
FIG. 17 depicts the input waveform of a label sensor, the output waveform as a running average the output waveform as a cumulative average, and the digital output based on the cumulative average output.
FIG. 18 shows the operational flow of a cascaded difference filter.
DETAILED DESCRIPTION
Various embodiments of the present invention will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies through the several views. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto.
Several embodiments of the detection sensor are described. These embodiments provide exemplary hardware implementations and operation flows of the process taken to detect external events, such as label transitions. These embodiments include a system that can account for noise and other variations in the sensing conditions that may create voltage drifts in amplifiers without requiring adjustments by the user. The system included in these embodiments can also determine the presence of external events occurring at random frequencies that produce detection signals spanning a very wide bandwidth, even in the presence of noise.
Although the exemplary embodiments are directed to capacitive type label sensors, many other sensor types can be implemented by the present invention and these sensors may be used for many purposes in addition to sensing label transitions. Other examples of sensors include but are not limited to optical sensors, ultrasonic sensors, and inductive sensors. Other sensors and sensor applications that apply to this invention are well known in the art.
With reference to FIG. 1, a basic capacitive type label sensor system 100 is shown. The system 100 includes a capacitive sensing unit 102 that receives the label web 108 . Labels 110 are periodically spaced along the web 108 . Typically, a feeding mechanism (not shown) supplies the label web 108 continuously to the sensing unit 102 . The sensing unit 102 then feeds a sensed signal through communication cable 104 to a processing module 106 that interprets the signal to determine that a label is present.
FIG. 2 illustrates some of the elements of the capacitive sensing unit 102 . The sensing unit 102 includes a sensing electrode 112 that is surrounded by a shielding electrode 114 . Though FIG. 2 illustrates the shielding electrode 114 surrounding the front, back, left, and right sides of the sensing electrode 112 , the shielding electrode 114 will also cover the top of the sensing electrode 112 as well. A reference electrode 116 is positioned across the gap or opening 124 from the sensing electrode 112 and the shielding electrode 114 and is connected to ground 122 .
The sensing unit 102 also includes electrical connection 118 that leads from the sensor electrode 112 to processing circuitry used to detect events from the change in signal occurring at the sensor electrode 112 . Electrical connection 120 leads from the shield electrode 114 to driving circuitry used to eliminate mutual capacitance between the sensor electrode 112 and shield electrode 114 .
FIG. 3 . illustrates the effect of providing a sensing electrode and a shielding electrode. The separation of the sensing electrode 112 from the ground electrode 116 results in a capacitance 126 (C Probe ) which exists in the gap 124 . A capacitance 128 (C shield ) exists in the gap 124 between the shielding electrode 114 and the ground electrode 116 and other undesired ground surfaces. C shield 128 differs from C Probe 126 because of the variance in the geometry and spacing of the shielding probe 114 from the ground probe 116 as compared to the geometry and spacing of the sensing probe 112 from the ground probe 116 . Additionally, the capacitance experienced by the shield electrode 114 will differ from C Probe 126 because the shield electrode 114 will experience stray capacitance C stray between itself and other undesired ground surfaces such as a grounded metal housing 127 surrounding the electrodes. These additional capacitances are not experienced by the sensor electrode 112 due to the presence of the shielding electrode 114 .
Driving the shielding electrode 114 with a voltage waveform having the same characteristics as the waveform applied to the sensor electrode 112 results in little or no mutual capacitance between the two electrodes. This effect is desirable because for proper label detection, the sensing electrode 112 must only be influenced by the material present in the gap. The electronics necessary for driving both the sensing electrode 112 and the shielding electrode 114 are described herein with reference to FIG. 4 .
To sense the presence of a label or the label web, the sensing electrode 112 is periodically driven to a potential by the sensor electronics 130 through electrical conductor 118 . The frequency of the voltage waveform is much greater than the highest frequency at which the labels will pass through the gap 124 . This frequency is controlled by a system clock. A 2 MHz system clock resulting in a 2 MHz waveform is typical. The clock pulse is fed to a sensor dedicated monostable multivibrator 136 through line 140 . The dedicated multivibrator 136 is also connected to line 118 which leads to the sensing electrode 112 . Line 118 is also connected to a DC power source (not shown) through a resistor 138 .
The multivibrator 136 discharges the capacitance 126 between the sensing electrode 112 and ground 116 upon receiving each clock pulse from line 140 . The voltage at the sensing electrode 112 is reduced to ground potential or zero since the multivibrator completes a short to ground. The multivibrator then opens the discharge path and the voltage on the sensing electrode 112 begins to charge back toward the level of the DC power source. The rate of charge is governed by the time constant or product of the resistance of resistor 138 and the capacitance 126 .
The capacitance 126 varies depending upon whether the label 110 is present in the gap or only the web 108 is present. If the label is present, the dielectric value increases which increases the capacitance. The resistance of resistor 138 stays the same so the time constant increases for the recharging of the potential on the sensing electrode 112 . The multivibrator 136 produces an output pulse on line 104 whose width is determined by the rate at which the voltage recharges on the sensing electrode 112 . Thus, the pulse width of the sensed signal output from the sensor unit 102 varies in proportion to the capacitance of the gap 124 created by the label 110 or the web 108 . The pulse width modulated signal on line 104 is then fed to the processing module 106 for subsequent processing.
To isolate the sensing electrode 112 from noise sources such as surrounding areas of differing potentials, shielding electrode 114 is also driven to a similar potential with a resulting waveform of exactly the same frequency by a shield dedicated monostable multivibrator 132 . The waveform is provided to the shielding electrode through electrical conductor 120 .
To drive the shielding electrode 114 so that the mutual capacitance between the shielding electrode 114 and the sensor electrode 112 is minimized, the capacitance between the shielding electrode 114 and the ground electrode 116 , as well as other stray capacitances experienced by the shield electrode 114 , must be considered. Ideally, the recharging waveform of the shielding electrode 114 should replicate the recharging waveform of the sensor electrode 112 at all times.
To match the recharging waveforms, the time constants must be made equal and the recharge cycle for each must begin at precisely the same time. This synchronization is accomplished by feeding the shield dedicated monostable multivibrator 132 the same clock pulse 140 that is fed to the sensor dedicated monostable multivibrator 136 . To match the time constants, the recharge resistor 134 connecting the dedicated multivibrator 132 and the shielding electrode 114 to the DC power supply (not shown) must be properly matched to the capacitance existing between the shielding electrode 114 and the ground electrode 116 and other undesired ground surfaces. Since C Probe does not equal the capacitance experienced by the shield electrode 114 including C Shield and C Stray , the resistance of the shield recharge resistor 134 will not be equal to the resistance of the sensor recharge resistor 138 .
The sensor electronics 130 of FIG. 4 permit the shield electrode 114 to be independently driven. The multivibrators 132 and 136 operate in unison to generate the independent signals and thereby prevent mutual capacitance from developing between the signal and shield electrodes. One skilled in the art will recognize that other methods of reducing the mutual capacitance are also available, such as using a buffer amplifier (i.e. voltage follower) to supply a potential to the shield electrode 114 that mimics the potential applied to the signal electrode 112 , although the dual-multivibrator method is far superior in its ability to create an identical fast-slewing discharge slope.
FIG. 5 illustrates the system electronics. The embodiments of the electronics of the invention described herein are implemented as logical operations in the detection system. The logical operations are implemented (1) as a sequence of computer implemented steps running on a computer system comprising the processing module and (2) as interconnected machine modules running within the computing system. This implementation is a matter of choice dependent on the performance requirements of the computing system implementing the invention. Accordingly, the logical operations making up the embodiments of the invention described herein are referred to as operations, steps, or modules. It will be recognized by one of ordinary skill in the art that these operations, steps, and modules may be implemented in software, in firmware, in special purpose digital logic, analog circuits, and any combination thereof without deviating from the spirit and scope of the present invention as recited within the claims attached hereto. These operations may be implemented by instructions contained in a computer program product, such as programming stored on a storage media or transferred as a propagated signal. In the preferred embodiment, the modules described herein embody a microprocessor.
The sensor electrode 112 feeds its detection signal (i.e. the recharge signal) to the sensor electronics 130 . The pulse width modulated periodic signal from the sensor electronics 130 travels to a low pass filter module 142 where it is then integrated into a varying DC analog output signal. The cutoff frequency of the low pass filter 142 is selected so that the high frequency content of the pulses is removed. The low frequency component which represents slow changes in the sensor capacitance passes through to create the varying DC signal.
The width of the pulse produced by the sensor electronics 130 varies depending upon the capacitance of the gap 124 , which is governed by whether a label is present in the gap 124 . If a label is present, the pulse width is greater than when only the web is present. The greater the pulse width, the greater the DC level of the signal output by the filter 142 , which varies proportionally to the pulse width.
The varying DC signal travels to the adjustable amplifier module 144 . This module 144 takes the DC signal and amplifies it to a greater level suitable for digitization. Ultimately, the system determines the presence of a label edge by determining whether the DC signal rises or falls. Amplifying the signal expands the rise or fall so that it is easily detected when digitized.
The amplified varying DC signal travels to an analog-to-digital (A/D) converter module 146 which samples the signal to produce a steady stream of discrete values indicating the amplitude of the varying DC signal at any sampling time. The discrete amplitude values are then output through a serial data bus into a microcontroller module 152 .
The microcontroller module 152 receives the digitized stream of values representing the varying DC signal and then processes the signal to determine label edge transitions. The microcontroller 152 also automatically adjusts the offset voltage applied to the adjustable amplifier module 144 to compensate for voltage drift caused by changes in the ambient conditions, such as temperature and humidity, and changes in label stock. Additionally the microcontroller 152 automatically adjusts the threshold used to determine rising and falling signals to compensate for variation in overall signal levels caused by changes in label or web dielectric value. Therefore, the microcontroller 152 runs at least three processes contemporaneously, each of which is discussed herein. Alternatively, multiple microcontrollers could receive the digitized data to reduce the number of processes that must be performed by each one.
In one embodiment, the microcontroller 152 applies a cascaded difference filter module 156 to the digitized data to remove noise components so that the rise and fall of the varying DC signal is more easily detected. The operation of the cascaded difference filter will be discussed in greater detail below.
The microcontroller 152 automatically adjusts the threshold used by the cascaded difference filter 156 to determine the presence of a label edge by continuously analyzing the peak-to-peak amplitude of the varying DC signal. The automatic threshold adjustment function is performed by the adjustable threshold module 154 . The operation of the adjustable threshold module 154 will also be discussed in greater detail below.
The microcontroller 152 also automatically adjusts the offset voltage that is applied to the adjustable amplifier module 144 . The microcontroller 152 continuously analyzes the mean value of the varying DC signal to determine whether the offset is appropriate. The microcontroller 152 outputs a pulse width modulated signal whose pulse width varies depending upon the offset voltage error. If the microcontroller 152 determines that the adjustable amplifier 144 offset is either too high or too low, then it alters the width of the pulse that it generates. If the offset is too high, the pulse width is increased, and if the offset is too low the pulse width is decreased.
The PWM signal generated by the microcontroller 152 travels to another low pass filter module 150 . The low pass filter 150 integrates the fixed frequency PWM signal down to a DC offset correction voltage. This low pass filter 150 has a cutoff frequency that is set so that the high-frequency content of the PWM signal is removed. Therefore, a 0% duty cycle signal (no pulse) results in a ground level DC offset correction voltage output, and a 100% duty cycle signal (full width pulse) results in a maximum level DC offset correction voltage output.
The DC offset correction voltage created by the low pass filter 150 is fed to a scalar amplifier module 148 that amplifies the DC offset correction voltage to an amount suitable to correct the offset voltage error of the adjustable amplifier 144 . The adjustable amplifier 144 receives the amplified DC offset correction voltage and adds it to the varying DC signal before it is output to the A/D converter 146 . The offset adjustment process is discussed in greater detail below. The low pass filter 150 and scalar amplifier 148 and microcontroller 152 operate together to form an offset adjusting module.
FIG. 6 illustrates the operational flow of the data acquisition and background routines performed by the microcontroller 152 . At operation 158 , the system becomes initialized so that it is ready to begin receiving, processing, and storing data from the A/D converter. Operation 160 includes scheduling background tasks so that once data is received, the microcontroller 152 can begin to automatically adjust the threshold and offset and apply the cascaded difference filters. Once these tasks are scheduled, a service interrupt is provided to operation 172 which begins to receive data samples from the A/D converter.
Process operation 174 then applies a 1× (every sample) difference filter, discussed below, to remove the DC component from the data, and look for signal transitions. Once the difference filter has generated output, control operation 176 feeds the output into storage at store operation 170 . Control operation 176 sends a return from interrupt back to schedule operation 160 . The background routine begins once the return from interrupt signal is received.
During the background routine, Process operation 162 applies the cascaded difference filters to the data being provided by the A/D converter. The cascaded difference filters look for signal transitions and generate a digital pulse whose rising and falling transitions correspond to the presence of leading and trailing label edges.
The background routine also involves evaluate operation 164 which receives the raw signal data that has been filtered and stored. This operation analyzes the data to determine several specific values that are subsequently used to adjust the threshold and offset voltages in operation 166 . During the background routine, monitor operation 168 continuously oversees the processing, evaluation, and adjustment tasks and flags the schedule operation 160 when a problem occurs.
FIG. 7 a depicts the signal sampling, data accumulation, and raw data evaluation routine in more detail. This routine derives the data that is used to determine the raw signal's amplitude and its relative position between ground and the amplifiers voltage rail.
Receive operation 178 begins to accept data through the serial I/O bus from the A/D converter and stores the digitized voltage levels in data arrays. One data array (Vmax) contains the highest signal levels detected by operation 182 since the beginning of an adjustment interval and another array (Vmin) contains the lowest signal levels detected by operation 186 since the beginning of an adjustment interval.
Query operation 182 detects whether the present sample is greater than the value stored in the Vmax array. If so, the value stored in the Vmax array is replaced with the current value at replace operation 184 . Then increment operation 180 increases the sample counter by 1. The sample counter tracks the number of samples processed during a given adjustment interval. If the current value is not greater than the Vmax value, then control moves directly to increment operation 180 .
Query operation 186 detects whether the present sample is less than the value stored in the Vmin array. If so, the value stored in the Vmin array is replaced with the current value at replace operation 184 . This query operation occurs in parallel with query operation 182 so that control moves from either query operation to increment operation 180 at the same time. Also, once these query operations and replace operation 184 are finished, the data received is stored at storage operation 194 of FIG. 7 b.
The Vmax and Vmin arrays accumulate the highest and lowest signals sampled during the adjustment interval. At the end of each interval, which is detected by operation 188 monitoring the sample counter and query operation 190 determining that the sample counter has reached its target, the data stored at operation 194 in the Vmax array is averaged at operation 192 , as is the data stored in the Vmin array, to produce an average Vmax and an average Vmin. These values are used in both the automatic threshold and automatic offset voltage adjustments.
Query operation 196 detects whether all of the adjustment criteria has been met, which includes determining that average values for both Vmax and Vmin are known. If they are not known, the control returns to monitor operation 188 which looks for the end of the next adjustment interval. If they are known, then control moves to perform operation 198 where both the threshold and offset routines are then performed and the arrays are reset. The process then repeats which allows the sensor to continually optimize the threshold and offset settings based on data from the previous adjustment interval.
The process for automatically adjusting the threshold value used to detect a rising or falling transition is depicted in FIG. 8 . This threshold adjustment routine sets the threshold at a desired percentage of the peak-to-peak raw signal amplitude to optimize the threshold for the raw signal level. This method maintains a high degree of noise immunity over a wide range of input signal amplitudes.
At calculate operation 200 , the peak-to-peak raw signal amplitude (Vpeak) is found by subtracting the average Vmin value previously determined from the average Vmax value that was also previously determined. Once Vpeak is known, query operation 202 detects whether Vpeak is less than the minimum allowable value. This operation is necessary because the threshold voltage must remain at least above a minimum level regardless of the Vpeak to avoid noise interference. If query operation 202 detects that Vpeak is below a minimum value, adjust operation 204 sets the threshold voltage to its minimum value.
If query operation 202 detects that Vpeak is above or equal to its minimum value, flow moves to adjust operation 206 . Here, the threshold voltage is obtained by multiplying Vpeak, the peak-to-peak raw signal amplitude, by the desired percentage to produce the appropriate threshold. The threshold voltage has no upper limit other than the limit indirectly imposed by the potential difference between ground and the voltage rail of the amplifier module 144 . After the threshold voltage is adjusted, operational flow returns to await the calculation of the next average Vmin and Vmax values. The system continuously optimizes the threshold voltage for variances in the raw signal amplitude in this manner.
FIG. 9 shows the operation flow of the automatic offset, or drift compensation routine. This routine permits the system to maintain the mean signal level Vmean centered between the voltage rail of the amplifier module 144 and ground. Centering Vmean in this way allows maximum signal compliance and measuring accuracy. This routine compensates for amplifier output voltage drift that occurs as a result of changes in the ambient conditions including humidity and temperature, or the dielectric constant of the label which may change from web to web.
Calculate operation 208 begins the routine by computing Vmean. The average Vmin previously determined is added to the average Vmax also previously determined. This sum is divided by two to find Vmean. Compare operation 210 subtracts the Vmean value from the amplifiers voltage rail value divided by two. Query operation 212 detects whether Vmean is greater than the voltage rail divided by two. If so, then flow moves to query operation 214 to test whether the difference between Vmean and the voltage rail divided by two is larger than a chosen minimum adjustment value.
If the difference is not larger than the chosen minimum, then no offset adjustment is required because Vmean is sufficiently centered between the voltage rail of amplifier module 144 and ground. Therefore, inhibit operation 216 maintains the PWM duty cycle and the routine returns to the beginning where it awaits the next Vmin and Vmax. If query operation 214 detects that the difference is larger than the chosen minimum, then adjust operation 220 increases the duty cycle of the PWM signal being sent to the low pass filter 150 which results in an offset adjustment that lowers Vmin and Vmax when an inverting amplifier 144 is used to magnify the signal. A non-inverting amplifier 144 could be used as well, in which case the duty cycle of the PWM waveform would be decreased to decrease Vmin and Vmax. The offset amount applied is the amount necessary to make (Vmin+Vmax)/2=Vcc(voltage rail)/2.
If query operation 212 detects that Vmean is not greater than Vcc/2, then query operation 218 tests whether the difference is larger than the chosen minimum required. If the difference is not larger, then Vmean is sufficiently centered and inhibit operation 216 maintains the PWM duty cycle and the routine returns to the beginning where it awaits the next Vmin and Vmax. If the difference is larger, then adjust operation 222 decreases the duty cycle of the PWM waveform that results in an increase in Vmin and Vmax when the amplifier 144 is inverting. Again, a non-inverting amplifier 144 could be used as well, in which case the duty cycle of the PWM waveform would be increased to increase Vmin and Vmax. The offset amount applied is again the amount necessary to make (Vmin+Vmax)/2=Vcc/2.
FIG. 10 illustrates a typical waveform that results from a label to web to label transition. The line with the round data point markers shows a typical waveform in the presence of virtually no background noise. As can be seen, the signal level is high when the capacitance is high due to the presence of both the label and its supporting web. When the label moves out of the gap 124 so that only the web is present, the capacitance decreases and the signal level falls. Then, a new label enters the gap 124 and the signal level rises back to a high state.
The waveform with triangular data points depicts the signal when background noise is present, and the dashed line shows the ideal digital output produced by the processing module in response to the digitized input waveform. The ideal digital output indicates that the pulse goes high when the signal falls below the threshold and the pulse returns to the low state when the signal rises above the threshold. The system may be configured so that the falling signal threshold and the rising signal threshold are not equal. Also, it should be noted that the time frame of the label to web to label transition, depicted as 0.5 milliseconds, can vary greatly in operation. Typically, start up and shut down cycles, where the web is accelerating from rest or decelerating to rest, can cause label transition durations to vary from normal operating speed durations by a factor of 1000.
Detecting both the leading and trailing edges of the waveforms is desirable. Analog components can detect these edges but due to the variance in operating speed from rest to normal, it requires a system that can differentiate the transitions from near DC to high frequencies. Analog components cannot easily differentiate across such a broad bandwidth and are also very sensitive to ambient conditions. Therefore, digital filters are preferred in finding the transitions.
One technique for locating transitions in a signal is to quantify the change in the signal from sample to sample by subtracting adjacent data values. This subtraction (or difference) can be implemented through a digital finite impulse response filter. The basic equation describing this filter is y ( t ) = ∑ n = 0 n = ( N - 1 ) h ( n ) · x ( t - n )
In this equation, x(t) represents the input waveform and y(t) represents the output waveform that has been filtered. N represents the total number of filter coefficients to be convolved with the input waveform. The filter coefficients are h(n). The filter coefficients corresponding to subtracting adjacent data values (to be referred to as a “1×” difference filter) are shown in Table 1 and the resulting amplitude values are shown in the passband plot of FIG. 11 (assuming a 65 microsecond sampling interval).
TABLE 1
1x Differencing Filter Coefficients
Array number
1x difference filter
(n)
coefficients h(n)
0
1
1
−1
The 1× difference filter is a fast filter because it accounts for every data sample point in the signal. As can be seen, the frequency plot of this filter slopes positively with increasing frequency from zero to the Nyquist sampling limit that equals one half of the sampling frequency. At DC, the passband amplitude is zero, and the passband amplitude peaks at the Nyquist limit.
FIG. 12 shows the input waveform for a label to web to label transition with background noise present. Also shown in FIG. 12 is the output of the 1× difference filter applied to the input waveform. The DC component is removed by the filter but the transitions cannot be resolved because the filter is too fast. To slow down the filter, the interval between samples considered by the filter are lengthened by only looking at data points spaced farther apart. For example, instead of taking the difference between every data point, the difference between every fourth data point can be taken instead. This filter is known as a 4× filter. Its coefficients are shown in Table 2.
TABLE 2
4x Difference Filter Coefficients
Array number
4x difference filter
(n)
coefficients h(n)
0
1
1
0
2
0
3
0
4
−1
5
0
6
0
7
0
The frequency characteristic for the 4× filter (assuming a 65 microsecond sampling interval) are shown in FIG. 13 . As can be seen, the 4× filter provides two passbands from DC to Nyquist limit. The effect of the 4× filter on the input waveform can be seen in FIG. 14 . The rise and fall transitions are now more apparent. However, high frequency noise remains in the output signal. Ordinarily, the bandwidth of the input signal for 4× filter should be limited to one-fourth of the Nyquist limit to prevent high frequency noise from discoloring the output. The input waveform corresponding to the output waveform of FIG. 14 was bandwidth limited by the 1× filter, which only requires that the band be limited to the Nyquist limit (with the Nyquist limit being defined as the sampling interval of the 1× differencing filter or the rate at which the input waveform is being sampled). To limit the bandwidth for the 4× filter, the input coefficients can be modified to causes the filter to also act as a low pass filter. Adjusting the filter so that a running average of the original waveform is performed before the subtractions are made will establish the low pass effect. This running average can be done by making the coefficients equal to one-fourth of the value used when no averaging is performed. The averaging coefficients are shown in Table 3.
TABLE 3
4x Differencing Filter Coefficients (with averaging)
Array number
4x difference filter
(n)
coefficients h(n)
0
0.25
1
0.25
2
0.25
3
0.25
4
−0.25
5
−0.25
6
−0.25
7
−0.25
The passband characteristics of the 4× filter with averaging can be seen in FIG. 15 . The two passbands are still provided up to the Nyquist limit but both passbands' amplitudes are reduced. The higher frequency passband's amplitude is greatly reduced relative to the lower frequency passband's amplitude.
FIG. 16 shows the input waveform and the waveform output by the 4× difference filter using averaging. The transition thresholds are still apparent and the high frequency noise is greately attenuated. The high frequency noise's amplitude is well below the level necessary to trigger a false label edge detection.
Implementing this averaging technique digitally is difficult because the input waveform's data points must be buffered over a long period of time. To minimize the amount data that must be buffered while averaging, the system can be configured to compute a cumulative average rather than a running average. A running average is one that is updated with each new data point. A cumulative average is one that combines successive data points into a single value. Rather than storing each data point's value, the average for every four consecutive data points can be stored for comparison to the average of the next four consecutive data points for example. The output waveform produced by the filter using cumulative averaging will be every fourth data point of the output waveform produced by using running averaging.
FIG. 17 illustrates the input waveform, the running average output waveform, the cumulative average output waveform, and the digital output waveform based on the cumulative average filter. The cumulative average waveform contains one-fourth as many data points as the running average waveform but still provides sufficient granularity to detect the rise and fall transition thresholds. The digital output is triggered high when the fifth cumulative averaging data point's amplitude is below the falling threshold. The digital output is triggered back to low when the seventh cumulative averaging data point's amplitude is above the rising threshold.
Employing the cumulative averaging technique allows the system to implement the digital filter more quickly while requiring less memory usage. These two effects permit numerous difference filters of varying “speeds” to be cascaded. Using numerous filters provides the maximum bandwidth for evaluating the signals, and start up and shut down accelerations and decelerations on the web do not cause the label edges to become undetectable. Cascading the filters can also prevent false detections due to aliasing.
FIG. 18 illustrates the operational flow for the cascaded difference filter architecture and routine. At input operation 224 , the filter receives input data x(t) from the A/D converter. The analog bandwidth limit of the A/D input signal x(t) is specified by the sampling interval for acquiring data from the A/D converter.
Once data is received, update operation 226 updates the average output value for each of the time intervals under consideration. Difference operation 228 calculates the difference value y(t), as previously described, for the fastest filter being used. Query operation 230 evaluates whether a positive or negative transition is currently required to change the output state. If looking for a positive transition, then query operation 232 tests whether y(t) is greater than the positive or rising threshold.
If y(t) is greater than the positive threshold, then state operation 234 changes the output state of the system to indicate a leading edge transition. Then control returns to input operation 224 . If y(t) is not greater than the positive threshold, then query operation 242 detects whether the last filter has been checked. If so, then control returns to input operation 224 . If not, the filter operation 240 calculates y(t) as previously described for the next fastest filter, and then control returns to query operation 230 .
Back at query operation 230 for the first pass, if looking for a negative going transition (y(t)<0), then flow moves to query operation 236 to test whether y(t) is less than the negative or falling threshold. If it is, then state operation 238 changes the output state of the system to indicate a trailing edge transition, and control returns to input operation 224 . If y(t) is not less than the negative threshold, then flow moves to query operation 242 to determine whether the last filter has been checked. If so, control returns to input operation 224 . If not, control moves to filter operation 240 which calculates y(t) for the next fastest filter. Then control returns to query operation 230 .
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention. | A system and method are disclosed for detecting the occurrence of an external event. The system eliminates the need for users to adjust amplifier offsets as well as detection thresholds by continually analyzing the signal and optimizing the offset and threshold values accordingly. Additionally, the system detects the external events in a noisy environment when the duration of the events vary by several orders of magnitude by employing cascaded difference filters. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to covers for golf club heads, particularly to protective covers made for single-handed operation, and which have simple construction, are convenient to use, and easy to fabricate.
[0003] 2. The Prior Art
[0004] Several types of protective covers for golf clubs are in use or proposed. Typically, the protective cover is made of fabric and put on over the head of the golf club, as in FIG. 14 hereof. The conventional protective cover A is pouch-shaped to cover both a head and an upper portion of a shaft of a golf club. The conventional protective cover A is longitudinally slit to allow easy insertion of the head and shaft of the golf club. A slide fastener Z is attached to the slit portion of the cover A and is opened before placing the cover A onto the golf club, then closed to protect the head and the upper portion of the shaft. Protective cover A is inconvenient to use because the slide fastener Z must be manipulated using both hands whenever the cover A is put onto or taken off from the golf club.
[0005] U.S. Pat. No. 6,202,723, by the present inventor, as shown in FIG. 15, discloses a protective cover for a golf club that is selectively opened and closed by being bent along its length. This protective cover cannot be easily opened because the protective cover uses the cover's own resilience to assist its opening. Where the protective cover is layered with a fabric, the cover is thicker and more difficult to bend and fold. Thus, it can be difficult to open and shut the protective cover with a single hand. Also, a hinge formed on a central portion of the cover body forms a hump when the protective cover is opened for inserting the golf club into the cover, which can make it less convenient to insert the golf club.
[0006] [0006]FIG. 16 illustrates a further known protective cover for a golf club, as disclosed in U.S. Pat. No. 6,119,742. This cover includes a pair of cover bodies and a hinge between and connecting them. This hinge too forms a hump when the protective cover is opened for inserting the golf club, reducing the ease of use by encouraging the golf club to shift to one side when placed into the open cover. Further, this cover comprises a top wall F 1 , a side wall F 2 , and a bottom wall F 3 , are all formed through an injection molding process, which requires different injection molds for accommodating various models and sizes of heads of golf clubs in any typical set.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a protective cover for a golf club which is easily opened and shut merely by grasping the protective cover with a single hand, and which has simple construction, thereby being convenient to use and facilitating its fabrication.
[0008] Another object of the present invention is to provide a protective cover for a golf club, a lower portion of the cover being formed by injection molding, thereby reducing its weight and being useable with the head of any golf club.
[0009] A further object of this invention is to provide a golf club cover having a simple opening and closing structure, thus reducing its manufacturing cost.
[0010] In order to accomplish the above objects, the present invention provides a protective cover comprising a fabric body with a head portion for covering and protecting the head of the golf club and a shank portion extending downwardly therefrom for enclosing a shaft of the golf club. An internal frame gives shape to the cover in its shank and in a lower part of the head. A hinge extends longitudinally of the frame, forming pair of wings along opposite sides of the hinge line for opening and closing the cover. Fastening means are attached to both of the free side edges of the wings, so they can be detachably interlocked with each other to keep the cover closed about the golf club. An elastic device may optionally be attached to an outer surface of the frame and the wings for biasing the frame into the open position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a perspective view showing a protective cover for a golf club according to one embodiment of this invention, in its closed position;
[0012] [0012]FIG. 2 is a perspective view of the protective cover for the golf club of FIG. 1, in its open position;
[0013] [0013]FIG. 3 is a perspective view of an internal frame for the cover of FIGS. 1 and 2, which is carried within the cover to give it form and shape and to control its function;
[0014] [0014]FIG. 4 is a vertical sectional view through the shaft portion of the cover of FIGS. 1 - 3 , showing the cover with its fastening means locked;
[0015] [0015]FIG. 5 is a vertical sectional view similar to FIG. 4, showing the cover for a golf club with its fastening means being released by finger pressure from a user;
[0016] [0016]FIG. 6 is a vertical sectional view similar to FIGS. 4 and 5, showing the cover for a golf club when nearly completely opened;
[0017] [0017]FIG. 7 is a perspective view showing a head and upper portion of a shaft of a golf club within the protective cover of FIGS. 1 - 6 ;
[0018] [0018]FIG. 8 is a perspective view of a second, modified protective cover, somewhat similar to FIGS. 1 - 7 of the present invention;
[0019] [0019]FIG. 9 is a perspective view of a third form of protective cover for golf clubs, with the cover fully closed;
[0020] [0020]FIG. 10 is a perspective view of the protective cover of FIG. 9, slightly opened;
[0021] [0021]FIG. 11 is an enlarged perspective view of the portion “a” encircled in FIG. 10;
[0022] [0022]FIG. 12 is a vertical sectional view of a shank portion of the protective cover of FIG. 9;
[0023] [0023]FIG. 13 is an enlarged plan view of the part “b” encircled in FIG. 12;
[0024] [0024]FIG. 14 is a perspective view of one conventional protective cover for a golf club;
[0025] [0025]FIG. 15 is a perspective view of another known protective cover for a golf club; and
[0026] [0026]FIG. 16 is a perspective view of a further known protective cover for a golf club.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] As shown in FIGS. 1 - 7 , a protective cover A for a golf club according to the present invention is comprised of a cover body 20 and an internal frame 22 . An elastic opening means 24 is also conveniently provided, but may be an optional feature. The cover body 20 is made of a fabric, and includes a head portion 26 for covering and protecting a head H of a golf club C (FIG. 7) and a shank portion 28 extending downwardly for enclosing a portion of a shaft S of the club.
[0028] The internal frame 22 is covered by the cover body 20 except, if desired, at its free edges 40 , 40 . The frame 22 is formed with living hinges 30 , 30 extending longitudinally along two sides of a central portion 32 . Wing portions 34 , 34 of the frame are swung about the hinges 30 , 30 for opening and closing the cover. Fastening means 36 , 38 are formed at the ends of the elastic means 24 , at side edges 40 , 40 of the frame 22 , as shown in FIGS. 3 to 6 . The fastening means comprise a locking hook 36 at one side edge 40 of the frame 24 and a locking projection 38 at the other side edge 40 thereof. The frame 22 has a head portion 42 and an opposite, lower, shank portion 44 .
[0029] The elastic opening means 24 is attached to the outer surface of the frame 22 . It is arranged or formed to bias the wings 34 , 34 of the frame 22 by its resilience toward the open position. It may be formed of resilient plastic or metal as may be most convenient, durable, reliable, and otherwise suited to the task, or be a simple rubber or other elastic band or cord.
[0030] The cover body 20 for enclosing the golf club C is made of any suitable fabric, woven or felted, etc., and synthetic or natural, etc., in either or both of the head portion 26 and the shank portion 28 . In the present embodiment, the cover body 20 consists of an inner layer 46 in contact with the golf club C and an outer layer 46 exposed on the outside. The layers are conveniently adhered permanently on their faces to the frame 22 .
[0031] According to this first embodiment of the invention, the lower or shank portion 44 of the frame 22 is of the same length and circumference as the shank portion 28 of the cover body 20 . However, the upper, head portion 42 of the frame 22 is shorter than the head portion 26 of the cover body 20 in order that the cover A be adaptable to cover any of most all types of golf clubs regardless of the size of the head of any particular club. That is, in accordance with the invention, the upper portion 44 of the frame 22 extends only to a part of the length of the head portion 26 of the cover 20 , generally less than half that of the cover head portion 26 . With this construction, a single injection-molded frame 22 can be used with a great variety of cloth covers 20 , each cover—but not the frame—being adapted to each particular golf club, whether it is a wood or an iron and for each club number and for each manufacturer or line of clubs. Thus, one expensive injection mold makes a single frame of a size that can be used for a multitude of covers, interchangeably.
[0032] The fastening means 36 , 38 formed on or attached to the side edges 40 , 40 of the frame 22 are made of flexible, resilient material so as to be released by an inward pressing on the one fastening means 38 , as depicted in FIG. 5. Preferably, the fastening means 36 , 38 are made of synthetic resin having superior elasticity. In this embodiment, the fastening means consist of a locking hook 36 at one side edge 40 of the frame 22 and a locking projection 38 at the other side edge 40 thereof. Instead of these devices, magnetic means fixed in cooperating, contacting relationship at exposed portions of both side edges 40 , 40 of the frame 22 may be used.
[0033] In this first embodiment, the frame 22 includes two living hinges 30 , 30 extending longitudinally of the frame 22 and spaced apart by center portion 32 , so that the hinges do not form a central hump upon opening of the protective cover A. This is in contrast to known protective covers having just one hinge. Since the hinges 30 , 30 are not raised and only the wings 34 , 34 outwardly of the hinges 30 , 30 are swung, the golf club C is easily received within the protective cover A atop the center portion 32 .
[0034] A cover 120 with internal frame can have just one living hinge 130 , as shown in FIG. 8, in a second, modified embodiment of the invention. Other hinge devices besides the living hinges shown may be used as may be suitable, such as pin and socket types, as are well known in the mechanical arts.
[0035] In the first and second embodiments, a single elastic means 24 or 124 for biasing the wings 34 , 34 of the semi-cylindrical frame 22 in the direction of opening is attached to the outer surface of the frame 22 at the wings 34 , 34 . Alternatively, two or more elastic means 24 or 124 can be attached at two or more positions on the outer or inner surface of the frame 22 , across one or more of the hinges 30 or 130 , so as to urge the wings 34 , 34 of the protective cover smoothly to open.
[0036] In the embodiments shown, the frame 22 has a semicircular cross-section. The frame 22 may alternatively have an oval cross-section or a polygonal cross-section, such as a square or a hexagonal section.
[0037] The frame 22 is disposed between the inner layer 46 and the outer layer 48 of the cover body 20 and is principally enclosed within the cover body 20 , with only the fastening means attached to the wings being exposed outside the cover fabric 20 .
[0038] As described above, in the protective cover A for the golf club C, the wings 34 , 34 of the frame 22 are optionally biased to the open position by the force of the elastic means 24 . Thus the frame 22 with such elastic means tends to remain open, and in that position the golf club C can be placed into the protective cover A. To accomplish this, the golf club C is held by one hand of a user and the protective cover A is held by the other hand. After the head H and the upper portion of the shaft S of the golf club C are received by the protective cover A, the user's other hand grips and closes together both side edges 41 , 41 of the protective cover A, swinging them about the hinge 130 or hinges 30 , 30 into close contact with each other. The hook and protrusion 36 , 38 or the like lock together in a snap-fitting manner, easily locking the frame 22 closed with a single hand, thus being very convenient to use.
[0039] For taking the protective cover A off the head H of the golf club C, the fastening means 38 of the frame 22 is pressed by the user's thumb. Then, the locking projection 38 formed at one side edge 40 of the frame 22 moves downwardly or inwardly of the shank until it is disengaged from the locking hook 36 at the other side edge 40 of the frame 22 . Since the wings 34 , 34 positioned on both sides of the frame 22 may be biased by the elastic means 24 in the directions shown by the arrows in FIG. 5, the wings 34 , 34 are swung about the hinges 30 , 30 so as to open outwardly. If no elastic means 24 is used, then the wings are opened manually or by lifting the club shaft out of the cover. Thus the protective cover A easily is taken off of the head H of the golf club C.
[0040] FIGS. 9 to 11 illustrate a third embodiment of a protective cover, at B, according to this invention. In the first and second embodiments of this invention, above, the cover A has a locking hook 36 at one side edge 41 of the protective cover and a locking projection 38 at the other side edge 41 thereof, thus allowing the protective cover A easily to be opened or closed. However, it may be difficult to form or install the locking projection 38 and the locking hook 36 on the side edges 40 , 40 of the frame 22 , so the manufacturing cost of the mold for the frame 22 or 122 may be undesirably increased, thus resulting in increased manufacturing cost for such a cover. This third embodiment provides a protective cover with a simpler structure for the internal frame and locking means than the first and second embodiments, thus providing a lesser manufacturing cost and likely being more convenient to use.
[0041] The protective cover B of the third embodiment of the invention includes a cover body 220 and a frame 222 , and optionally an elastic means 224 . The cover body 220 is fabric, with a head portion 226 for covering and protecting the head H of the golf club C, and a shank portion 228 extending downwardly from the head portion 226 and enclosing the shaft S of the golf club C. The cover body 220 , as in FIGS. 12 and 13, covers the internal frame 222 . The frame 222 is provided with two living hinges 230 , 230 extending longitudinally along two sides of a central portion 232 of the frame 222 . Wings 234 , 234 of the frame 222 are formed to swing about the two hinges 230 , 230 to be selectively unfolded and folded.
[0042] In accordance with this embodiment of the invention, the frame 222 has on its upper side edges 240 , 240 a fastening means 250 comprising a Velcro® hook and eye fastener system. A first piece 252 of the Velcro fastener is attached along one side edge 240 of the frame 222 , at and over a surface 254 of one edge 240 , while a second, cooperating piece 256 of the Velcro is attached along the other side edge 240 of the frame 222 , at and over a surface 258 , in such a way as to detachably interlock with the piece 252 . The cover body 220 does not cover this part of the frame but is attached to the wings spaced apart from the edges 240 , 240 . In order to increase the bonding force between the one side edge 240 and the other side edge 240 of the frame 222 , the two edges to which the Velcro is attached have a V-shaped male edge 254 and a cooperating V-shaped female edge 258 , respectively, for increasing the contact area of the Velcro. Other surfaces can also be used, as oval and circular sections. In this embodiment, the two pieces 252 and 256 of the Velcro are attached along the contact surfaces 254 , 258 , respectively. Preferably, each piece 252 , 256 of the Velcro is attached to two or three positions on the associated contact edge 240 , 240 at regular intervals. As such, according to this third embodiment of this invention, the two pieces 252 , 256 of the Velcro are utilized as the fastening means 250 , so the protective cover 220 is simple in its construction, thus the protective cover is easily manufactured. In addition, the two pieces 252 , 256 of the Velcro and the edge surfaces 254 , 258 firmly interlock with each other upon closing of the protective cover 220 , thus preventing the protective cover from being unintentionally opened, increasing the convenience of use of the cover B.
[0043] Further, a middle of the frame 222 at its upper edges 240 , 240 , and corresponding portions of the cover body 220 are formed with a finger hole 260 that facilitates opening and closing the protective cover. In addition, the open, lower end of the frame 222 is beveled, thus further assisting in easily opening and closing the protective cover with the user's fingers on one hand. The optional elastic means 224 , if present, is attached to the surface of the frame 222 on wings 234 , 234 to bias the wings by its resilience in the opening direction.
[0044] In the protective cover B according to the third embodiment, the wings 234 , 234 of the frame 222 are optionally held open by the force of the elastic means 224 . Thus in a normal state the frame 222 remains open, so the golf club C can be placed into the protective cover B. In use, the golf club C is held by one hand of a user and the protective cover B is held by the other hand. The head H and the upper portion of the shaft S of the golf club C are inserted into and covered by the protective cover B. Next, by grasping the protective cover B with one hand, both side edges 240 , 240 of the open cover B are brought into contact with each other, shutting the cover about the club head and shaft. Further, to take the protective cover B off the head H of the golf club C, a user inserts a thumb and finger into the hole 260 of the frame 222 and separates the sides of the hole 260 . Alternatively, the user opens the inclined lower end of the frame 222 with his fingers.
[0045] As soon as the fastening means 250 is released, the protective cover B is fully opened either by the resilience of the elastic means 224 , or manually, thereby allowing easy removal of the protective cover B from the head H of the golf club C.
[0046] The fastening means of the third embodiment is simple in its construction and so is easily manufactured. In addition, the first piece 252 of the Velcro firmly interlocks with the second piece 256 when closing the protective cover, thus preventing the protective cover from being inadvertently removed from a golf club. Such a fastening means ensures a high bonding strength, thus allowing the protective cover to be reliably opened and closed many times, therefore being convenient to use.
[0047] As described above, the present invention provides a protective cover for golf clubs, which includes a frame that is opened and shut with a single hand. Thus, upon releasing the lock on the protective cover, the wings of the protective cover are swung outward about the hinge or hinges under the bias of the elastic means and opened fully, so that the golf club can be easily inserted into the cover. For shutting the protective cover, the wings of the frame are swung about the hinge line or lines until the locking means are fastened, thus closing and locking the protective cover. For again opening the protective cover, the frame is pressed by a user's thumb adjacent the lock or pulled apart along the Velcro® fastener until the fastening means is released and the protective cover is opened by the resilience of the elastic means, and the protective cover is easily then taken off from the head of the golf club. As a result, the protective cover for the golf club of the present invention, in any of its three embodiments, can be opened or closed with a single hand, thereby being convenient to use and rapidly put on or taken off the head of the golf club.
[0048] Although several 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. For example, the elastic band may be omitted from the protective cover at some cost savings with only a small lessening of the convenience of the cover in use. | A protective cover for a golf club includes a cover body and an internal frame and may include an elastic means for biasing the cover to an open condition. The cover body is made of cushioning fabric material and includes a head portion for covering and protecting the head of the golf club and a shank portion extending downwardly from the head portion for enclosing an upper part of the shaft of the golf club. The frame is principally covered by the cover body and comprises a hinge, wings that swing about the hinge to open and close the protective cover, and fastening means at free edges of the wings. The elastic means if present is attached to the outer surface of the frame and resiliently biases the wings of the frame to the open position. Part of the cover at the head is unsupported by the interior frame, to accommodate club heads of various sizes and shapes. The cover can be opened and closed with just one hand of the user. | 0 |
This invention relates to commonly assigned co-pending U.S. patent application Ser. No. 07/551,331 titled REMOVABLE FASTENER WITH ELASTIC LINKING MEANS, filed July 12, 1990.
BACKGROUND OF THE INVENTION
The present invention is directed to a multipart externally barbed fastener element which provides a resilient linking means connecting a plurality of fastened work pieces having differing coefficients of thermal expansion.
DESCRIPTION OF THE RELATED ART
Rigid fasteners have been used to attach plastic panels or plates to metal plates or frames. The plastic plate has a much larger coefficient of thermal expansion than the metal plate, thereby causing the plastic plate to elongate and contract more than the metal plate in response to temperature change. This difference in thermal expansion causes the plastic plates to expand and contract more than metal plates, thus causing the plastic to warp or buckle between the rigid fasteners. The warped or buckled plastic plates display a poor finished appearance.
In addition to the problems arising from the different coefficients of thermal expansion of the plastic plate and the metal plate are thermal expansion differences between the fastener and the work piece. If the fastener is made of metal, and at least one of the plates being fastened is made of a plastic material, the axial thickness of the plate will elongate and compress at a greater rate than the length of the fastener. This leads to two problems. When the plastic plate compresses more than the metal fastener, the plate becomes loose and is subject to vibration. When the plastic plate elongates more than the metal fastener (i.e. the thickness of the plate is larger than the length of the fastener), the plastic experiences creep in the area of the fastener head. Resilient fasteners permit elongation and compression in both the fastener and the plates without loosening.
In French patent No. 736,058 issued Sept. 12, 1932, there is disclosed an elastic bolt which permits lengthening of the bolt while maintaining a compressive force between the work piece and bolt. One embodiment of the elastic bolt has a sinusoidal shape which is elongated by a nut. The elongated bolt preloads the threads and prevents the nut from loosening.
The French patent does not teach the use of an elastic bolt in a work piece without a nut. It cannot be used where there is no access to the threaded portion of the bolt. Torque applied to the shank component is transferred through the bolt to the head. The application of torque to the shank component will tend to cause twisting of the bolt. The twisting deforms the bolt and reduces its strength. The twisting also may interfere with the removal of the bolt from a workpiece.
In my U.S. Pat. No. 4,854,797, issued Aug. 8, 1989, there is disclosed a threaded fastener with resilient linking means for use in a work piece. This fastener does not require a nut to elongate the bolt and hold a work piece in compression. A torque transmitting mechanism transfers torque applied to the head component to the shank component and causes axial displacement of the shank component in an aperture in a work piece against the resilient biasing of the resilient linking means. The torque transfer means is integrated into the bolt and designed to break as a predetermined torque is applied to the bolt head.
In my copending application Ser. No., 07/551,331, titled Removable Fastener with Elastic Linking Means there is disclosed a fastener with resilient linking means having a longitudinal opening for the application of torque to a threaded shank component. Torque transmitted to the shank component causes axial displacement of the shank component in an aperture in a work piece against the resilient biasing of the resilient linking means.
It is an object of my invention to provide a low cost, easily manufacturable, barbed fastener having a resilient linking means which when installed in a work piece maintains a compressive force between the fastener and work piece.
Another object of my invention is to provide a fastener with a resilient linking means which permits a limited amount of axial and lateral compression and elongation of the work piece and still maintain a compressive force between the fastener and work piece. This and other objects and advantages of my invention will be made apparent by the following disclosure of the invention and discussion of the preferred embodiments.
SUMMARY OF THE INVENTION
According to the present invention, a fastener is provided which comprises a head component; a barbed shank component; and a resilient linking means connecting the head and shank components. The fastener has a longitudinal opening adapted to receive a tool for the application of force in a driving engagement with the shank component.
The present invention also provides a method of fastening a plate member to an internally ribbed work piece using this fastener by engaging the fastener with the ribbed aperture in the work piece; inserting the tool into the longitudinal opening; applying force to the shank component sufficient to cause axial displacement of the shank component against the resilient biasing of the linking means to maintain the head and shank components in axial tension; and removing the tool.
A plate having an aperture slightly greater than the barbed shank component is secured to another plate or mounting bracket having internal ribs corresponding to the externally barbed shank component. The fastener is inserted through the outer plate and forced into the ribbed inner plate or plates. The application of force causes displacement of the shank component against the resilient biasing of the resilient linking means. The application of force application is then removed and the two plates are firmly attached through the axial tension of the resilient linking means.
The resilient fastener of this invention can absorb both the axial displacement due to the change in thickness of the plastic plate, and the lateral displacement normal to the fastener axis due to the change in length of the plastic plate, as the plastic plate undergoes thermal elongation and compression.
Once the fastener is installed, further axial displacement of the plates is permitted by a slight elongation of the resilient linking means. Lateral movement between the plates is also permitted by the elongation and bending of the resilient linking means. Axial contraction of the plate or wear in the vicinity of the head component is absorbed through contraction of the resilient linking means. The resilient fastener is able to maintain a tight connection over a broad range of temperatures and after partial wear of the fastener head or outer plate.
One application for the present invention is to fasten a plastic body panel to a metal frame such as a plastic pickup bed to a metal chassis. The difference between the coefficient of thermal expansion between the plastic and metal are particularly suited to the fasteners of the present invention. The fasteners securely attach the pickup bed to the chassis and permit elongation and contraction of the plastic with respect to the metal.
It is an advantage of the present invention to provide a low cost, easily manufacturable and installable, fastener containing a resilient linking means between the head and shank components. It is a further advantage of the invention to provide a fastener which permits a limited amount of axial compression and elongation of the work piece and still maintain a compressive force between the fastener and work piece. It is a further advantage of my invention to provide a fastener which permits a limited amount of lateral compression and elongation of the work piece without buckling or warping and still maintain a compressive force between the fastener and the work piece.
An additional benefit of resilient fasteners lies in a cushioning effect between the plates. Plates attached using the resilient fastener are permitted some axial and lateral movement with respect to one another. Shocks and bumps are partially absorbed by the resilient linking means.
BRIEF DESCRIPTION OF THE DRAWINGS
The earlier mentioned objects and advantages as well as others will become apparent to those skilled in the fastener arts after reading the following description with reference to the accompanying drawing in which:
FIG. 1 is a perspective view of a fastener in accordance with the present invention;
FIG. 2 is a cross sectional view of the fastener of FIG. 1 taken along the line II--II of FIG. 1 and showing an assembly of two work pieces;
FIG. 3 is a cross sectional view of the fastener shown in FIG. 2 undergoing lateral displacement between the two plates;
FIG. 4 is a cross sectional view of the fastener of FIG. 1 taken along the line II--II of FIG. 1 showing an alternative assembly of two work pieces;
FIG. 5 is a perspective view of a first alternative embodiment of the fastener; and
FIG. 6 is a perspective view of a second alternative embodiment of the fastener.
DESCRIPTION OF PREFERRED EMBODIMENTS
In view of the present disclosure those skilled in the fastener arts will readily recognize the usefulness of the present invention in numerous applications in which an assembly is formed, for example, by attachment of a first component to a second component. Thus, for example, the fastener of the invention can be used to fasten together adjacent plates or to fasten a plate to a frame member, such as in the assembly of a motor vehicle body, etc. The fastener of the invention is particularly useful for attaching together two or more adjacent sheets or plates having different coefficients of thermal expansion. The axial resiliency of the fastener facilitates lateral shifting of fastened components over each other without buckling even when one or both are plastic. In such applications, it is particularly preferred that the fastener components having an interface with the fastened components comprise plastic material, rather than metal or the like, to reduce or eliminate wear of the plate at such interface. Also, the resilient linking means according to certain embodiments of the invention provides a substantial measure of lateral flexibility as well as axially elastic resiliency. This can be advantageous in allowing a fastened assembly to absorb lateral impact and/or to allow relative lateral shifting of one component relative another in the assembly due to thermal expansion/compression or the like.
Turning now to FIG. 1, fastener 2 essentially is illustrated as comprising three components, a head component 4, an externally barbed shank component 6, and a resilient linking means 10.
Head component 4 consists of a lower portion 14 and a unitary circular lip portion 8 having an external diameter larger than the external diameter of lower portion 14.
Shank component 6 is formed as a generally cylindrical externally barbed member and includes an opening 12 for receiving the direct application of force from a tool. Openings 12 extend completely through head component 4 and resilient linking means 10 and partially through shank component 12. Barbs 13 are molded onto shank component 6. Barbs 13 are of the type and shape found on press-on type fasteners commonly used in the automotive industry. Barbs 13 may be slotted or staggered. The length and flexibility of barbs 13 may be selected to best serve the strength requirements of the particular application in a manner well known in the fastener arts.
Resilient linking means 10 coaxially connects head component 4 to shank component 6 a fixed axially spaced distance apart while fastener 2 is in a free state. Openings 12 extend longitudinally along axis A and centrally through head component 4, resilient linking means 10 and into shank component 6.
Fastener 2 is shown in FIG. 2 attaching an outer plate 20 to an inner plate 22. Inner plate 22 may be any internally ribbed component such as a bracket or plate. Inner plate 22 has internal ribs 26 machined to receive shank component 6. Internal ribs 26 may be one or more circular slots cut into inner plate 22, alternatively, ribs 26 may be one or more circular projections extending to receive barbs 13. Additionally, internal ribs 26 may be triangularly shaped to mate with barbs 13 and provide an even greater degree of holding power. Many types and shapes of ribs are known in the art which are designed to retain barbed fasteners. Resilient linking means 10 coaxially connects shank component 6 with head component 4 and has an outer diameter smaller than the diameter of shank component 6.
A variety of means exist and are well known in the art for firmly attaching resilient linking means 10 to head and shank components 4, 6. To achieve this firmly secured connection, resilient linking means 10 may be molded into an opening or grove 24 within the head and shank components 4, 6.
Alternatively, head component 4, shank component 6 and resilient linking means 10 may be essentially simultaneous manufactured through coinjection. In this coinjection process, a mandrel is inserted through a mold and head and shank components and resilient linking means are injection molded around the mandrel. As the mandrel is removed, a coaxially aligned opening 12 runs partially through the fastener.
Openings 12 are configured to mate with a tool 30. Openings 12 extend completely through head component 4 and resilient linking means 10. Openings 12 may extend into shank component 6 or shank component 6 may be made completely solid. Tool 30 is inserted through openings 12 until the end portion 31 of tool 30 engages wall 33 of shank component 6. The continued application of force on tool 30 causes the axial displacement of shank component 6 with respect to head component 4.
The installation and use of the resilient fastener 2 shall be described below and shall generally refer to FIGS. 2 and 3. The alignment of openings 12 through head component 4, resilient linking means 10 and shank component 6, permits the free insertion of tool 30 therethrough. Fastener 2 is freely inserted into inner plate 22 until lip portion 8 engages contact area 9 of outer plate 20. Barbs 13 collapse when inserted through aperature 23 in outer plate 22. Barbs 13 remain collapsed until they engage ribs 26. Ribs 26 permit the internal resilience of barbs 13 to partially extend. Rearward axial movement of shank component 6 is restrained by the engagement of barbs 13 with ribs 26. Fastener 2 is inserted beyond this initial engagement by applying force to tool 30 thereby elongating resilient linking means 10 and causing the axial displacement of shank component 6 against the resilient biasing of resilient linking means 10. This elongation maintains the head and shank components in axial tension. The elongation of resilient linking means 10 lengthens fastener 2 a distance greater than its free state length.
Tool 30 is provided with a stop 35 to prevent the excessive elongation of resilient linking means 10. Stop 35 engages head component 4 and prevents the additional application of force on shank component 6. Resilient linking means 10 is not fully elongated and axial elongation (i.e. increasing thickness) of plates 20, 22 further axially elongates resilient linking means 10. Axial compression (i.e. decreasing thickness) of plates 20, 22 reduces the amount of elongation of resilient linking means 10, but resilient linking means 10 always remains elongated a distance greater than its free state length. This constant elongated state of resilient linking means 10, even when plates 20, 22 are axially compressed (i.e. decreased thickness), maintain plates 20, 22 and fastener 2 in compression at all temperatures.
Fastener 2 is shown undergoing a lateral displacement of plate 20 along the direction of arrow B in FIG. 3. Resilient linking means 10 is slightly distended and distorted from this lateral displacement but continues to transfer a compressive load between inner and outer plates 20, 22. Lip portion 8 may freely rotate about contact area 9.
Alternatively, fastener 2 may be designed to completely penetrate inner plate 22' as shown in FIG. 4. In this case, the interior surface 26' of inner plate 22' acts as a rib and retains barb 13. This alternative embodiment may be used when attaching a workpiece to a relatively thin plate. Barbs 13 collapse when inserted into outer plate 20 and remained collapsed until exiting the interior surface 26' of inner plate 22'. The internal resilience of barbs 13 cause them to extend beyond the radial periphery of opening 27 in inner plate 22' and prevent shank component 6 from moving axially rearward toward head component 4.
Head component 4 and shank component 6 may be made of any suitable material including metal or plastic, but are preferably made of a plastic material such as nylon or polytetrafluoroethylene. Resilient linking means 10 may be made of any resilient or elastomeric material having suitable compression and elongation characteristics. Typical materials include natural and synthetic rubbers and elastomeric plastic, of which many are known to one skilled in the art, some of which are commercially available, such as a product sold under the name TEXIN™ by Mobay Chemical Corporation.
Alternatively, the resilient linking means may be made with a spring rather than an elastomeric material. The spring may be of a coil type or leaf type design. In the alternative embodiment of fastener 2' shown in FIG. 5, resilient linking means 10' is a metal coil spring which may be elongated a distance greater than its free state length. In the alternative embodiment of fastener 2" shown in FIG. 6, resilient linking means 10" is made from four meal leaf springs 11 connecting head and shank components 4,6. Each leaf spring 11 is made from a metal band having fold 13 in its center. It is preferable to face fold 15 inward to reduce the overall size of the aperture needed to insert fastener 2".
Resilient linking means 10', 10" may be attached to head and shank components 4, 6, by a variety of techniques. Preferably, resilient linking means 10', 10" is placed in an injection molding tool and head and shank components 4, 6 are formed about either end. The alternative embodiment shown in FIGS. 5 and 6 have the advantage that the metal spring has a low coefficient of thermal expansion which minimizes the elongation and compression fasteners 2', 2" undergo due to a change in temperature.
It should be recognized and understood that the foregoing description of presently preferred embodiments of the invention are presented for exemplification and not limitation of the invention. Certain modifications and variations of the fastener will be apparent to the skilled of the arts in view of the present disclosure and the present or future state of the art, which modifications and variations are intended to be within the scope of the following claims. | A fastener is provided which comprises a head component; a barbed shank component; and a resilient linking means connecting the head and shank components. The fastener has a longitudinal opening adapted to receive a tool for the application of force in a driving engagement with the shank component. Also provided is a method of fastening a plate member to an internally ribbed work piece using this fastener by engaging the fastener with the ribbed aperture in the work piece; inserting the tool into the longitudinal opening; and applying force to the shank component sufficient to cause axial displacement of the shank component against the resilient biasing of the linking means to maintain the head and shank components in axial tension. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the guided transport of biological molecules or cells to which small magnetic particles have been attached, particularly when such molecules or cells are then to be detected optically in a chemical or biological assay.
2. Description of the Related Art
Physical extraction of biological cells and molecules from liquid biological solutions by exerting magnetic forces on attached magnetic labels (i.e., small magnetized particles) has been a widely adopted technique in medical and biological practice. The biological cells or molecules have magnetic labels attached to them, the labels being very small particles of magnetic material that are magnetizable by an external magnetic field. Such small particles of magnetic material are typically superparamagnetic, meaning that thermal effects are sufficiently large to destroy spontaneous domain formation and, therefore, they must be placed in an external magnetic field to acquire a magnetization. Thus, detection of the target cells or molecules is usually accomplished by applying such an external magnetic field that magnetizes the magnetic labels, exerts a magnetic force on them and extracts them from the liquid-form samples together with the cell and molecule to which they attach. Afterwards, a subsequent reading of, for example, optical signals emitted by fluorescent or luminescent compounds (dyes) previously also attached to the extracted cells or molecules is performed to identify the existence of the target molecules or cells. However, such an ensemble oriented extraction technique is incapable of producing detections at the single molecule level, because the target molecules are detected in the form of concentrated clusters or as droplets where signal scattering by unbound labels or liquid solution can be very high.
Referring to FIGS. 1A-1D , there is shown a schematic illustration of such a prior art method of magnetically extracting and optically detecting magnetically labeled molecules. In FIG. 1A there is seen a biological solution ( 1 ) containing the target molecules ( 2 ) to be detected and distinguished from molecules that are not of interest ( 3 ). FIG. 1B shows the target molecules ( 2 ) with magnetic labels ( 4 ) and fluorescent dyes ( 5 ) attached to them. FIG. 1C shows the fluid ( 1 ), passing in a channel ( 8 ) between the poles of a magnet ( 7 ). Solid arrows indicate the magnetization of the magnet. The magnetic labels have been attracted to either side of the channel by the interaction between the external magnetic field of the magnet and the induced magnetization within the labels, pulling their attached molecules with them. In FIG. 1D there is shown a subsequent identification of the labeled target molecules ( 4 ) by means of a beam of excitation light ( 9 ) and the optical detection of excitation fluorescence ( 10 ) in an optical detection system. ( 11 ). M. A. Reeve, (U.S. Pat. No. 5,523,231) teaches a method to isolate macromolecules using such magnetically attractable particles. Similarly, M. A. M. Gijs has published “A Magnetic bead handling on-chip: new opportunities for analytical applications,” Microfluid Nanofluid. Pp 22-40, 2004.
The prior art also teaches detection of labeled biological molecules or viruses with accuracy at the level of single molecules by the use of magneto-resistive (MR) sensors. D. R. Baselt et al., “A biosensor based on magnetoresistance technology,” Biosens. Bioelectron., vol. 13, pp. 731-739, October 1998, M. M. Miller et al., “A DNA array sensor utilizing magnetic microbeads and magnetoelectronic detection,” J. Magn. Magn. Mater., vol. 225, pp. 138-144, April 2001 and S. X. Wang et al., “Towards a magnetic microarray for sensitive diagnostics,” J. Magn. Magn. Mater., vol. 293, pp. 731-736, 2005.
Referring to FIG. 2 , there is schematically shown how such a prior art system can operate. The technique usually uses a regular array of identical MR sensors, one such sensor being indicated as ( 12 ). Each sensor is formed between an intersection of two sets of vertically separated horizontally directed parallel current carrying wires ( 160 ), ( 16 ) that are orthogonal to each other.
The individual patterned magnetic devices comprise two horizontal electrically conducting planar magnetic layers ( 13 ), ( 14 ), separated by a non-magnetic layer ( 15 ) and the array may be formed by patterning a larger horizontal film deposition of two horizontal planar magnetic layers separated by a non-magnetic layer.
Subsequent to (or prior to) their being patterned into the array of discrete devices ( 12 ), the magnetic layers are magnetized and the magnetization of one of the layers (nominally, the “bottom” layer ( 14 )) is fixed in spatial position and may be denoted the “pinned” layer and the magnetization of the other layer (nominally the “top” layer ( 13 )) is allowed to move freely and may be denoted the “free” layer. The direction of the magnetization of each layer is predisposed by providing the layers with some form of magnetic anisotropy, either a crystalline anisotropy that results from the layer deposition process or a shape anisotropy that results from the patterning, or both.
As a result, by a proper choice of currents in the two sets of wires ( 100 ), ( 16 ), the magnetization of the free layer can be moved and can be caused to be parallel to or anti-parallel to that of the fixed layer. It is well known in the prior art that such sensors display two resistance states according to the relative directions of the two magnetic moments. When the moments are aligned (parallel), the resistance is low and when the moments are anti-aligned (anti-parallel) the resistance is high. Thus, a measurement of the resistance of any element in the array will give an immediate indication of the alignment of its magnetizations. The basic idea is then to magnetize the label of the captured molecule ( 4 ) and to have its magnetization switch the direction of the free layer magnetization of the sensor element over which it is trapped. The switching is detected as a resistance change and it gives an indication of a trapped particle.
Typically such an array of sensors is formed beneath a substrate surface (not shown) that is furnished with chemical binding sites that are specific to the molecule or cell being detected. For simplicity of the figure and ease of visualization, a captured target molecule ( 2 ) and its attached magnetic label ( 4 ) is shown as being bound to one of the conducting lines ( 160 ). In practice, the conducting line is beneath the substrate and the molecule is bound to a site on the substrate surface. When such a molecule binds to one of the sites, its label is then in a fixed position over the portion of the sensor array beneath the binding site. In this figure, the molecule ( 2 ) is shown as being directly over one of the sensors ( 12 ). After the magnetic labels that are not bound to the substrate surface are removed, typically by flushing the surface, the remaining magnetic labels are subjected to an external magnetic field that is perpendicular to the substrate plane, whereupon the labels generate an induced magnetic field ( 17 ) that projects into the underlying MR sensor and is parallel to the magnetic layers of the sensor. As already noted above, because the magnetic particles are so small, they are “superparamagnetic”, meaning that thermal energy exceeds the energies that would create stable domains, so there is no spontaneous magnetization. Consequently, the particle must be subjected to an external magnetic field so that it may become magnetized and produce its own magnetic field. The surface attachment of the magnetic labels ensures their close proximity to adjacent MR sensors, to enhance the effects of the small magnetic signal they generate. However, this method does require the process of capturing the target molecules on the substrate surface, as well as the removal of the labels that do not have their molecules attached to surface sites. Since label binding to molecule and molecule binding to surface requires two separate incubation processes, this new method is theoretically slower than the conventional optical method in its preparation step, because in the optical identification method a single incubation is enough to accomplish both magnetic label attachment and dye attachment to the target molecules. In addition, the MR signal variation between patterned MR matrix cells can be sufficiently great so that the magnetic labels need to exceed a certain size to achieve acceptable accuracy and repeatability in their detection.
We will note at this point that studies within the prior art have shown that sensor arrays such as those illustrated in FIG. 2 , can also be used to move small magnetic particles, rather than to detect them. It was shown in prior arts by E. Mirowski et al., “Manipulation of magnetic particles by patterned arrays of magnetic spin-valve traps,” J. Magn. Magn. Mat., vol. 311, pp. 401-404, 2007 and by J. Moreland et al., “Microfluidic platform of arrayed switchable spin-valve elements for high throughput sorting and manipulation of magnetic particles and biomolecules,” Moreland, also in US published patent application 2005/0170418, teaches that physical manipulation of a single magnetic particle can be achieved with patterned arrays of magnetic multi-layer thin film structures. The magnetic particles can be trapped by a magnetic pattern and later released from the pattern by switching the magnetization of one of the magnetic layers between different directions. Referring to FIGS. 3A and 3B , there is shown schematically how such a prior art process achieves these objects by an illustration with a single labeled particle and a single trilayered device formed by patterning a multilayered thin film structure.
The patterned device ( 12 ) in both FIGS. 3A and 3B includes a free magnetic layer ( 13 ) formed of a magnetic material such as CoFe, a non-magnetic inter-layer ( 15 ), formed of a dielectric material such as AlOx and a pinned layer ( 14 ), formed of material similar to that of the free layer. A single molecule ( 2 ) to which is attached a magnetic label ( 4 ) is adjacent to the device in FIG. 3A . A switching current ( 19 ) I switch in an adjacent electrical line ( 16 ) rotates the magnetic moment ( 50 ), M free of the free layer so that it is parallel to the magnetic moment ( 6 ), M pinned , of the pinned layer. The parallel magnetic moments effectively produce magnetic charges on the lateral edges of the device which, in turn, induces a magnetization ( 7 ), M label , in the label ( 4 ). The induction process produces a net magnetic attraction between the lateral edge of the device and the magnetized label, bringing the label to the device and trapping it there.
Referring next to FIG. 3B , there is shown schematically the configuration of FIG. 3A wherein the switching current ( 19 ). I switch in the line ( 16 ) has been reversed in direction, causing the magnetic moment ( 5 ) of the free layer ( 13 ) to reverse direction and become antiparallel to the magnetic moment ( 6 ) of the pinned layer ( 14 ). The lateral edges of the device now have net zero magnetic charge, releasing the label ( 4 ) and allowing its induced magnetization to essentially disappear.
In whatever method of detection is used, in order to achieve a speedy detection and counting process at the single molecule level, it is preferable that the biological preparation steps be as simple as possible. For example, the one-step incubation process, as used in the conventional optical method described in FIGS. 1A-1D is regarded as being advantageous compared with the MR assay method as described in FIG. 2 .
However, to realize single molecule counting, the biological cells or molecules must be manipulated and detected individually, producing sufficient physical separation to ensure the separate response of each individual molecule in space or in time. This is a basic requirement. The conventional ensemble magnetic label extraction and optical detection scheme illustrated in FIG. 1A-1D will not be able to separate each individual label or molecule, even using state-of-the-art flow-cytometry or micro-fluidics systems. In short, the MR sensing scheme illustrated in FIG. 2 is more likely to accomplish the goal of single molecule detection due to the controllable spatial separation between individual captured molecules that it provides.
U.S. Patent Application 2005/0170418 (Moreland et al) discloses using spin valve elements to trap, hold, manipulate, and release magnetically tagged particles, but there is no disclosure of transporting the particles. The prior art also discloses the following patents. U.S. Pat. No. 5,523,231 (Reeve) teaches magnetic extraction of molecules using magnetic beads. U.S. Pat. No. 5,691,208 (Miltenyi et al) shows magnetic spheres in a lattice format used to separate labeled cells from a fluid. U.S. Pat. No. 6,294,342 (Rohr et al) shows an assay method of binding magnetically labeled particles. U.S. Pat. No. 7,056,657 (Terstappen et al) teaches trapping and releasing magnetically labeled cells, but there is no disclosure of transport.
As noted above, each of the prior art methods, including optical detection and MR sensor detection, has its advantages and disadvantages. None of them provide a robust method of reliably detecting the presence of individual beads. It is the object of the present invention to provide such a method.
SUMMARY OF THE INVENTION
A first object of this invention is to provide a method of detecting the presence of small magnetic particles, particularly when such particles act as magnetic labels by being attached to biological molecules or cells.
A second object of this invention is to provide such a method that is sufficiently sensitive to detect single labeled cells or biological molecules.
A third object of the invention is to provide a method of detecting such presence when such labeled biological molecules or cells are in motion.
A fourth object of this invention is to provide such a method that detects the aforementioned magnetically labeled biological molecules or cells when such biological molecules or cells have been further labeled by one or more optically excitable dyes, whereby the magnetic label attachment and dye attachment comprise a single incubation process.
A fifth object of this invention is to provide a method of transporting and guiding magnetically labeled biological molecules or cells contained in a solution of such molecules or cells so that said molecules or cells can be isolated and detected singly A sixth object of this invention is to provide a method of transporting and guiding magnetically labeled biological molecules or cells contained in a solution of such cells so that said cells can be isolated and detected singly by means of radiation emitted by one or more optically excitable dyes.
A seventh object of this invention is to provide such a method that, in addition allows molecules to be extracted from such a solution and thereby identified optically without the disadvantageous effects of optical diffraction.
The objects of the present invention will be achieved by the use of an array or arrays of patterned multi-layered magnetic devices or of parallel single layer magnetic strips or “stripes” (rectangular layers of magnetic material that are longer than they are wide) that can be activated by adjacent current carrying lines. The strips or the devices will magnetically guide and transport the magnetically and optically labeled biological molecules to positions at which they can be individually counted by optical excitation of attached dyes and the detection of the excitation radiation produced by the dyes. Some of these patterned devices are substantially identical to devices used as sensors in the array of FIG. 2 , but as will be further described, they will be operated in the manner described in FIGS. 3A-3B that generates the directed movement of magnetized labels and their attached cells and molecules rather than detecting them.
A. Transport and Guidance of Magnetically Labeled Particles.
This method of magnetic label trapping and release by a patterned magnetic film structure is utilized to transport the magnetic labels together with their attached biological molecules or cells to a desired position for optical detection and to extract the labeled molecules from a biological solution if it is so desired. Once the labeled molecules reach the position of an optical detection device, they can be individually detected and counted.
As noted, the molecules must be equipped with both the magnetic labels that provide their movement and the dyes that allow for their optical detection. This equipping can be done as a one step incubation process, which reduces the complexity of biological preparation. The additional ability to extract the labeled molecules from the solution for optical detection provides a better signal-to-background-noise ratio during detection by eliminating diffraction effects and strong background noise caused by the solution. Thus, the individual molecular transportation realizes the goal of single molecule counting and, finally, because the detection scheme uses a mature optical technique, the entire process is easier to be implemented. In the following we will briefly indicate how the array of patterned devices and alternative arrays of magnetic strips can be used to achieve the desired guidance and transport of the magnetic particles.
Referring next to FIGS. 4A and 4B , there is schematically shown a row of 5 exemplary trilayered devices (two magnetic layers separated by a non-magnetic layer), lettered a-e, each one being identical to the single such device of FIGS. 3A and 3B . The bottom of the pinned layer ( 14 ) of each device is contacted by a current carrying line ( 16 ) that is directed out of the plane of the figure. Note, into-the-plane currents are denoted by circles with crosses, out of the plane currents are denoted by circles with dots. A protective surface ( 17 ) covers the devices. A label ( 4 ) and an attached entity with dye molecules ( 5 ) is shown trapped between devices d and e by the magnetic field of the parallel magnetic moments (arrows) of both free and pinned layers of device d. The entity is drawn here as an exemplary biological molecule labeled optically by attached dye molecules ( 5 ). All the other devices have antiparallel magnetizations of their free and pinned layers and, therefore, have zero net magnetic charge on their lateral edges.
Referring next to FIG. 4B , there is shown the labeled ( 4 ) molecule of FIG. 4A now having moved to a new trapping position at device c as a result of the parallel alignment of the pinned and free layer magnetic moments in that device. The previously trapping device d has had the magnetic charge on its lateral edges set to zero by reversing the current (from in, to out, of the figure plane)) in the current carrying line beneath it ( 16 ), thereby releasing the label and allowing it to move to device c. Such a process can be repeated sequentially to carry a labeled particle in any direction along an array of such trilayered devices.
The success of the transport process described above requires the label to be able to feel the magnetic field from both the present trapping device and from immediately adjacent ones. Thus, the dimension of the magnetic label is preferably larger than the width of the devices and the device layers are preferably thick. A magnetic label whose size is smaller than or equal to the device width, or devices formed of thin magnetic layers, will not transport the molecules effectively.
To solve the problem of a magnetic label not being able to sense the magnetic field of an adjacent device, and of thereby not moving correctly when it is released by a device presently trapping it, an external field can be used to assist in moving the attached label to the edge of the present trapping device that faces the adjacent device to which the label is desired to be transported.
FIGS. 5A-5D show a schematic sequence of such a vertical field-assisted label transport. A set of x, y, and z Cartesian axes will identify the directions of fields and motions. In FIG. 5A , the magnetic label ( 4 ) is initially attracted by the field at the right edge of device d (with parallel pinned and free layer magnetizations) and is itself magnetized (arrow ( 55 ) within label ( 4 )) by the edge field of d with a vertical magnetization component along +z direction.
In FIG. 5B , an external magnetic field ( 100 ) along −z direction re-magnetizes ( 55 ) the label ( 4 ) with a −z component and the label moves to left edge of device d to attain a lower magnetic energy.
In FIG. 5C the external field is turned off and a current in adjacent line ( 16 ) beneath device c switches the free layer magnetizations of device c to be parallel to that of its pinned layer, while turning off the current beneath device d allows its free layer magnetization to revert to its original state. Thus, device d is now in an anti-parallel (net zero field) orientation and device c is in a parallel orientation. Therefore, the label ( 4 ) is released by d and captured by c. In addition, the magnetization ( 55 ) of label ( 4 ) has now been given a +z direction by the field of device c. Note also that the trapping effect can be understood in terms of the equilibration of the magnetic forces on label ( 4 ) or in terms of the minimum magnetostatic energy of the system of label and device.
In FIG. 5D , the same external field is applied and the label is again transported in the negative y direction along the array. This method relieves the requirement of large label size and thick film. The transport direction is also easily controlled by the applied field direction and the sequence of the trapping and release processes of adjacent devices. In this way, trapping and release of the magnetic label is also more reliable.
Besides using a MR sensor-type trilayered film structure of the type illustrated in FIGS. 5A-5D , where the resulting patterned devices have a free layer and a pinned layer, a single magnetic layer structure can also be used. Referring to FIGS. 6A-6D , there is schematically shown an example of such a single layer magnetic structure and an array of such structures. Unlike the multi-layered devices in FIGS. 5A-5D , in FIGS. 6A-6D only one magnetic layer exists and it is formed in the shape of a long strip or “magnetic stripe”. The magnetic stripe is assumed to have a relatively strong magnetic anisotropy along its lengthwise direction (x-axis direction) that is perpendicular to the transport route of the labels. Thus, the magnetization of the magnetic stripe is naturally along the x-axis direction if no magnetic field is externally applied. Consequently, there are no magnetic charges on the y-axis layer edges that will generate a field to attract magnetic labels. Label capture is only possible when the current carrying line ( 16 ) beneath the magnetic layer carries a current in the +x direction, generating a magnetic field in the magnetic layer ( 14 ) and magnetizing it in the +y direction. The strong magnetic anisotropy of the magnetic layer can be achieved by inducing a strong crystalline anisotropy along x-axis direction during layer formation. It can also be achieved by making the layer length along the x-axis much longer than the width in the y-axis direction, so a strong shape anisotropy along the x-axis can arise.
FIGS. 6A to 6D schematically represent exactly the same processes as in FIG. 5A to 5D , except that the trapping and release of the magnetic label ( 4 ) is not by parallel or anti-parallel magnetization orientations within a trilayered device, but by means of a current field being on or off in a single magnetic layer ( 13 ). The current field is produced by the currents in identical adjacent lines ( 16 ). The encircled cross shows a current into the plane. An advantage of this scheme is that the magnetic and electrical structures are simpler and the strength of the magnetic field generated by each film layer can be controlled by the current amplitude.
FIGS. 7A-7D then schematically shows another variation of the single magnetic layer or stripe scheme as in FIGS. 6A-6D . The six magnetic layers ( 13 ), denoted a-f, have an intrinsic anisotropy that gives them an easy axis (arrow) along y-axis direction. The spacing between the adjacent strips must be very narrow. At the “release” state, in which there is substantially no net trapping field, all layers are magnetized along the same direction as shown in FIG. 7A . Thus, the magnetic field from one strip's edge charges is compensated by the negative sign edge charges from the adjacent strips. Therefore, the effective field between the strips is close to zero. The magnetic label, ( 4 ) with attached entity ( 5 ), has no induced magnetization and it is free to move.
FIG. 7B shows that during a trapping state, the strip, d, is magnetized in a reverse direction, or antiparallel to the rest of the strips by a current in the current carrying line beneath it. Thus, the edge charges at the c/d interface (both “negative”) and the d/e interface (both “positive”) of the adjacent strips produce a net magnetic field, shown with dashed field lines ( 50 ), that, in turn, induces a magnetization ( 55 ) in the label ( 4 ). The advantage of this scheme is that unlike the scheme of FIGS. 6A-6D , after the present patterned strip is switched in magnetization direction, it does not require a current generated field to maintain the switched magnetization. Additionally, during the trapping state, the trapping field is generated by the edge charges from two adjacent strips, c/e and e/d instead of one trilayered device as in FIGS. 5A-5D and one strip as in FIGS. 6A-6D . Thus, the trapping field amplitude and gradient from the pattern can be higher than in previous cases.
Transport of the magnetic label along the patterned array can be accomplished with the same method as in FIGS. 5A-5D and FIGS. 6A-6D with the application of a DC magnetic field. However, due to the closeness of the patterns and higher edge fields in this configuration and the higher edge field between immediately adjacent strips, transport of the label can be made simpler. FIG. 7C shows that after the magnetization of strip c is switched to the same direction as that in strip d the resulting magnetic field (see dashed field lines ( 51 )) produced by the oriented combination of c and d changes the magnetization ( 55 ) of the magnetic label ( 4 ) and pulls the inductively magnetized label in the −y direction. As shown in FIG. 7D , the magnetization of strip d is then reversed so that it is now in its original state shown in FIG. 7A , the magnetic label has been automatically moved to the left without the aid of an applied field and it is now trapped between strips c and d. Therefore, this scheme simplifies the transport procedures by eliminating an external magnetic field.
Besides transport of each single label as described above, separation of two adjacent labels is equally important in order to ensure enough separation between the labels. E. Mirowski et al., cited above, describes an experimental demonstration showing that when several particles are experiencing the magnetic field from a film stack, they tend to form a chain linked by inter-particle fields and do not separate naturally. Thus, a specific procedure needs to be used to separate any interlinked magnetic labels from one another before their individual transport. Referring to FIGS. 8A-8D there is shown schematically a scheme for separating magnetic labels for individual transport using the patterned trilayer device structure as in FIGS. 5A-5D . An interlinked label chain (only two exemplary labels ( 4 ), ( 41 ), being shown here) can be separated with concurrent trapping of the magnetic labels by the closest devices. Here, in FIG. 8A , the labels are shown trapped between devices c/d and d/e. This trapping occurs because the magnetization of device c has been reversed to create a trapping field between devices c and d that traps label ( 4 ) and also label ( 41 ) behind it. In the following sequence the leading label ( 4 ) will be transported in a forward direction just as the individual label in FIG. 5 was transported. The difference is that the sequence also allows the trailing label ( 41 ) to be kept behind the leading label by being trapped at a location between devices that are behind the forward label ( 4 ).
Referring to FIG. 8B there is shown the application of an applied field ( 100 ) in the −z direction (large downward arrow). In addition, the magnetization of device e has been reversed to trap ( 41 ) between devices d and e. The external magnetic field ( 100 ) meanwhile moves ( 4 ) to a position between devices b and c.
Referring to FIG. 8C , the external field has been turned off and the magnetization of device c is switched to anti-parallel to release the label ( 4 ) while the magnetization of device b has been reversed to produce a parallel orientation of its magnetization and to attract label ( 4 ). The magnetization of device e is not reversed, so it continues to hold the other label ( 41 ). Referring to FIG. 8D , there is shown the repetition of the process of FIG. 8B , where now the applied field (downward arrow) causes label ( 4 ) to move in the −y direction to be trapped between devices a and b. Thus, through this sequential trapping/release process, which is substantially identical to that illustrated in FIGS. 5A-5D , the outermost label ( 4 ) can be separated from its adjacent neighbor ( 41 ) and transported away from successive elements of the label chain (not shown here) one by one. Thus, individual detection of the target molecule attached to each label can be achieved.
FIG. 9 schematically shows an additional feature that can help maintain single label transport. The label transport is realized within a transport channel bounded by channel edges ( 17 ) and ( 18 ). A succession of parallel magnetic strips ( 13 ) (or, equivalently, trilayered devices) are each contacted from below by current carrying lines ( 16 ) that can change the directions of the device or strip magnetizations. The channel has an inside cross-transport-route width between edges ( 17 ) and ( 18 ) that is larger than the diameter of each single magnetic label ( 4 ) and ( 41 ). However, the width is also smaller than twice of that diameter. Thus, using a scheme such as illustrated in FIGS. 8A-8D , but applied now to strips or devices, magnetic labels are always transported individually through the channel.
B. Magnetic Label Concentration and Controlled Alignment within Liquid Solution
To apply the single label transport scheme described above in real applications the labels need to be segregated and concentrated within the solution that contains diverse molecules and cells bound with magnetic labels and dyes. In addition, the concentrated labels need to be guided to the transport channel for individual label transport and ultimate optical detection. FIG. 10A schematically shows an example of a label guided transport and concentration structure that will achieve the objects of this invention. The device is a planar solution-confining structure that comprises essentially three regions, a sample pool ( 500 ), a concentration region ( 190 ) and a transport channel ( 170 ). Long magnetic thin film strips ( 13 ) are formed beneath the sample pool ( 500 ) that contains many labeled molecules ( 4 ). A strip in this context is a thin magnetic layer that is significantly longer than it is wide. A currentl carrying layer (not shown) runs beneath the strip to provide field variations. A funnel structure ( 190 ) is used to concentrate the magnetic labels at the entrance to the transport tunnel ( 170 ). Magnetic labels are captured by the strips ( 13 ) beneath the pool and moved from within the solution towards the channel entrance with the same transport mechanism as acts on the labels within the channel. After a label reaches the entrance to the channel ( 170 ), it is picked up and transported individually along the channel by substantially identical, though shorter, strips ( 13 ) according to the method illustrated in FIGS. 7A-7D and FIGS. 8A-8D .
Referring to FIG. 10B , there are shown a set of three identical parallel channels and funnel structures (as in FIG. 10A ) that are exemplary of a multiple channel scheme that could be used to guide labeled molecules to alternative examination positions. The guided transport in each channel can be done using its own array of magnetic strips ( 13 ) formed beneath the three channels ( 161 ), ( 162 ), ( 163 ).
It is worth noting that the transport of magnetic labels described above does not require the liquid solution to be within the channel. Thus, the labels can not only be guided away from the sample pool, but they can also be physically separated from the solution during the transport process. For example, labels can be elevated above the sample solution and physically detached from the solution. Optical detection of the labeled molecules can then be performed without diffraction from the liquid and without the interference of unbound dyes within the liquid, thereby yielding a higher signal to noise ratio.
C. Optical Detection of Single Molecules or Cells with Single Label Delivery and Positioning.
With the individual transport of the magnetic label as well as the attached target molecule to the desired final position, optical detection of the target molecules can proceed without the conventional 2D imaging of the entire sample surface or through an amplitude-population correlation that requires obtaining an absolute optical signal whose amplitude correlates with the molecule population. FIG. 11A shows a schematic illustration (magnetic strips not shown) of the optical detection of a single labeled and dyed molecule ( 187 ). A source of appropriately filtered optical excitation ( 22 ) of the dyed molecule transmits its radiation through a narrow region of the channel ( 170 ) where it impinges upon a single labeled molecule ( 187 ) and the radiation emitted from the excited dye molecules attached to the target molecules enters the optical detector ( 11 ) through a secondary optical filter that eliminates the light that caused the optical excitation. The detector, in this configuration, is located at the opposite side of the channel from the source, but it can also be on the same side.
FIG. 11B schematically shows a typical electrical signal produced by the radiation impinging on the optical detector. The vertical axis refers to the signal intensity, the horizontal axis refers to time. When no labels pass between the source and detector, there will be a nominal signal generated by the arrival of the filtered light from the source ( 90 ). The passage of a label between source and detector will block the source radiation and the signal might dip slightly ( 95 ). When the signal radiation excites the dye on the molecule, there will be a stimulated optical emission that will show up as a peak in the signal ( 97 ). If source and detector are on the same side of the channel, the absorption dips ( 95 ) may be replaced by slight peaks from label reflection that would be significantly lower than the peak produced by the stimulated emission of the dye ( 97 ).
Compared with conventional optical imaging or detection schemes, this method can utilize a highly focused excitation light and narrow-field-of-view optics, including fiber-optics, that will produce little background interference. In addition, since molecules are individually detected, the counting of molecules is not by signal amplitude, but by the number of dye emission peaks in the signal. This further enhances sensitivity and provides stability against noise.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features, and advantages of the present invention are understood within the context of the Description of the Preferred Embodiment as set forth below. The Description of the Preferred Embodiment is understood within the context of the accompanying figures, wherein:
FIGS. 1A-1D (prior art) are a schematic representation showing how magnetic labels can be used to attach to biological molecules in a liquid and the molecules can be extracted from the liquid by a magnetic field afterwards for optical detection.
FIG. 2 (prior art) is a schematic representation of a magnetoresistive (MR) sensor matrix on which a labeled biological molecule has been bound.
FIGS. 3A-3B is a schematic illustration of an MR type magnetic trilayer structure being used to capture and release a labeled biological molecule.
FIGS. 4A-4B is a schematic illustration of a labeled biological molecule being transported along an array of magnetic trilayer structures of the type illustrated in FIGS. 3A-3B
FIGS. 5A-5D is a schematic illustration of the transport of a labeled molecule along an array of magnetic trilayered structures in the presence and absence of an external magnetic field.
FIGS. 6A-6D is a schematic illustration of the transport of a labeled molecule along an array of single layered magnetic structures whose intrinsic anisotropy field is in the layer plane and perpendicular to the transport direction. The transport is produced in the presence and absence of an external magnetic field.
FIGS. 7A-7D is a schematic illustration showing the continual transport of a labeled molecule along an array of single layer magnetic structures, whose intrinsic anisotropy field is along the transport direction, with and without the aid of an external field as in FIGS. 6A-6D .
FIGS. 8A-8D is a schematic illustration showing a method of detaching a pair of labeled molecules and their transport along an array of patterned magnetic devices.
FIG. 9 is a schematic overhead view of labeled molecules being transported along a channel.
FIGS. 10A-10B are schematic overhead views showing how a solution containing many labeled biological molecules can be concentrated by being guided, transported and funneled along a single channel or multiple channels.
FIGS. 11A-11B is, in 11 A a schematic illustration of optical detection of labeled biological entities being transported along a channel and in 11 B a schematic illustration of an optical signal waveform generated by the detection process shown in 11 A.
FIGS. 12A-12D are schematic illustrations of four embodiments of the invention associated with different configurations of the patterned magnetic trapping devices.
FIG. 12E shows an overhead view of the structures in FIGS. 12A-12D with different horizontal cross-sectional shapes.
FIGS. 13A-13B are schematic illustrations showing two different embodiments of the invention associated with channeling and transport configurations of patterned magnetic trapping devices.
FIGS. 14A-14C are schematic illustrations showing three different embodiments of the invention corresponding to an optical detection system capable of detecting channeled labeled biological molecules.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention are devices for attracting, transporting and guiding small, typically superparamagnetic, magnetic particles and a method for using those devices to detect and count individual entities to which such magnetic particles are attached and on which, thereby, they act as magnetic labels. The magnetically labeled entities are preferably biological molecules or cells and a guidance and transport method using sequential trapping and release of the magnetic labels by an array of patterned magnetic structures will be disclosed.
The method of magnetic particle guidance and transport by a process of sequential trapping and release by a patterned magnetic film structure, such as that to be described in the following embodiments, can be utilized to form a biological assay where the target biological molecule or cell is individually manipulated and detected. First, through incubation processes, magnetic labels and optically excitable fluorescent dyes or self-luminescent chemical compounds are attached to the target entities, which are preferably molecules and cells. Then, a solution of such prepared molecules and cells with their attached magnetic labels and dyes are introduced into a confinement device within which the solution is held while the magnetically labeled cells or molecules are manipulated. This manipulation includes the individual capture of the magnetic labels by patterned magnetic devices and transported, through a sequential trapping and release process, over an array of the patterned magnetic structures formed beneath the confinement region. The array of patterned devices can be rectangle-shaped single layer magnetic strips, strips having other more or less regular geometrical shapes, or more complex patterned multi-layered magnetic devices such as magnetic trilayer devices, all of which are current activated. Before transport, the magnetic labels (and their attached biological molecules and cells) to be transported are concentrated by being guided through a funnel shaped region into a narrow, linear transport channel. There, the magnetic labels are transported one at a time and physically separated from each other, so that the individual labeled cells or molecules to which they are attached can be optically detected with less interference. In this way, the magnetic labels together with the bound molecules can be extracted and transported away from the original solution location and optically detected with single molecule or single cell level separation and accuracy.
Compared with conventional magnetic cell or molecule extraction and optical imaging or sensing techniques, this method enables single cell or single molecule detection. This method does not rely on fluidics to manipulate biological entities but uses more precisely controlled magnetic forces to guide single magnetic labels. In the detection process it does not rely on 2D imaging that incorporates too much background interference that limits the sensitivity level. Neither does it rely on optical signal amplitude correlation with the target population. With individual label transport, signal detection can be achieved by peak pattern recognition. For the case of one-to-one correlation between the transported label and the attached molecule, counting of molecules is nearly independent of the optical signal amplitude variations.
The advantage of this method compared with conventional 2D MR sensor assay method of FIG. 2 is that the present method does not require a capture process of the target molecules to the assay surface. It also avoids the necessity of a later removal of unbound magnetic labels. Thus, the biological preparation procedures before detection are reduced.
Besides, conventional optical method due to its mass sample detection of the optical signal, it is more accurate for cell applications, where the biological entity is relatively larger and can have many dye molecules attached to a single cell surface to produce significant signal. For molecule detection, optical signal from the dyes attached to the target molecules can be easily blocked by the larger magnetic labels. The MR sensor assay, on the other hand, prefers molecule level application. It requires proximity of magnetic label to the MR sensor to produce enough magnetic field. It also requires strong binding force between the captured entities and the assay surface so that that entities are not removed during unbound label removal process. Since cells are large in size, the magnetic force or flow force during the removal process may cause the binding to easily break.
In the embodiments of this invention, both biological cell detection and molecule detection can be readily adopted with little modification. For cell detection, the channel width needs to be larger than the size of a transport unit (a single cell coated by magnetic labels), but smaller than twice the size. For molecule detection, the transport unit is then a single label.
The embodiments to be described assume functional and commercially available magnetic labels that can satisfy non-agglomeration at zero field, can be magnetized and can be successfully coated with necessary biological or chemical compounds. Such elements have been successfully used in other prior art inventions. The transported unit in the embodiments can be magnetic labels attached with one or multiple biological molecules or cells coated with magnetic labels. Other entities to which magnetic labels can be attached can also be guided and transported by this invention. All necessary protection layers and coatings that enable the patterned multi-layer magnetic thin film structure to function in the relevant biological or chemical environments are assumed.
The Embodiments of this Invention Provide
1) A patterned magnetic thin film structure or device controlled by current induced magnetic fields to trap and release magnetic labels.
2) A method to transport a magnetic label across an array of the patterned devices through sequential trapping and releasing of the label with or without the aid of an external field.
3) A method to separate magnetically coupled labels for separate transport.
4) A label collection and guided concentration method utilizing the trapping and release mechanism within a funnel-shaped structure.
5) An optical signal detection method that uses peak pattern recognition.
Given the five aspects of the embodiments described above, the embodiments of this invention will be separated into five categories in terms of their
1—Trapping Structure, 2—Transport Method, 3—Label Separation, 4—Label Collection and Guided Concentration, 5—Signal Detection.
Thus, the possible structures can be any arbitrary combination of any sub type embodiment within the five categories listed.
1—Trapping Structure
Trapping and releasing of magnetic labels is through the edge field from the lateral edges of the patterned magnetic thin film structures. This edge field can be turned on and off by switching the corresponding magnetic layer magnetization to different orientations. Switching of the magnetic layer is preferably produced by, but not limited to, a magnetic field generated by an electrical current flowing close to the patterned films. The existence of a trapping field can also be described in terms of “magnetic charges,” on the faces of such lateral edges. Such charges are an alternative mechanism for describing the effects of a magnetization divergence within a region and can be pictorially thought of as an accumulation of arrow heads or tails within a closed surface.
Embodiment 1A
The trapping structure (also denoted a “device”), shown schematically in FIG. 12A , is formed beneath a protection layer that is not shown here. The term“trapping” as used herein refers to the capture and holding of a magnetized label in a substantially fixed position.
The magnetic labels are attracted by the magnetic fields of the trapping structure and they move against the protection layer's top surface which can be the bottom surface of a confinement device as will be illustrated below. The labels are transported along the top of the protection layer along a Direction 2 as indicated on the Cartesian coordinate system in the figure. The trapping structure is a multilayered device that includes four parts, a magnetic free layer ( 13 ), a non-magnetic spacer layer ( 15 ), a magnetic pinned layer ( 14 ) and a current conduction path ( 16 ) that can carry current ( 19 ) in either direction along Direction 1 as shown by the double-headed arrow. Free layer ( 13 ) magnetization can be in either orientation along Direction 2 . Spacer layer ( 15 ) serves to break the magnetic exchange coupling between the free layer ( 13 ) and pinned layer ( 14 ). Pinned layer ( 14 ) magnetization is pinned also along one orientation in Direction 2 (shown negative) and not easily switched by an external field. The Direction 2 pinning field in layer ( 14 ) can be created by a strong anisotropy field of the material forming layer ( 14 ), or from exchange coupling with an antiferromagnetic layer (not shown in this illustration, but which can be a part of the pinned layer) that would contact layer ( 14 ), or from a synthetic anitferromagnetic (SAF) structure connected to layer ( 14 ) (also not specifically shown, but which can be a part of the pinned structure). These methods are generally known in the art of making MR sensors and will not be described further herein.
It is noted that the patterned trapping structure can have a horizontal cross-sectional shape of any of a wide variety of geometrical forms, such as rhomboids, trapezoids or other quadrilaterals. FIG. 12E shows an overhead view of an alignment of the structures in FIGS. 12A-12D if the horizontal cross-sectional shapes of the free layer ( 13 ) were square, trapezoidal or rhomboid. In order to produce strong edge fields capable of trapping magnetic labels, it is preferable that adjacent patterned magnetic structures have facing parallel edges, but such parallelism between immediately neighboring structures can be accomplished by a variety of cross-sectional shapes that have straight edges but are not necessarily parallel to corresponding edges within the same structure. For ease of visualization and explanation, the exemplary shape that will be referred to herein and which is pictured in FIGS. 12A-12D is rectangular.
Electric current ( 19 ) flows in a current path along ( 16 ) within its plane. Direction 1 is perpendicular to Direction 2 . The field generated by current ( 19 ) switches free layer ( 13 ) magnetization into the same or opposite orientation to the positive direction of Direction 2 . During a trapping state, free layer ( 13 ) magnetization is switched to the same direction as the magnetization of pinned layer ( 14 ). During a release state, free layer ( 13 ) magnetization is switched opposite to that of pinned layer ( 14 ).
Embodiment 1B
Referring to FIG. 12B , there is shown schematically a device that is the same as that in FIG. 12A except that the adjacent current carrying line (( 16 ) in FIG. 12A ) is absent and the current ( 19 ) is carried by the interlayer ( 15 ).
Embodiment 1C
Referring to FIG. 12C , there is again shown schematically a trapping structure that would be formed beneath a protection layer. The magnetic labels would be attracted against the protective layer by the trapping structure beneath the layer. The trapping structure includes two parts, a single magnetic layer ( 13 ) and a current conduction path ( 16 ). The natural or normal magnetization of layer ( 13 ) is maintained by an internal field along the in-plane Direction 1 that is perpendicular to Direction 2 . The internal field of layer ( 13 ) can be from any one of, or a combination of crystalline anisotropy, shape anisotropy and stress-induced anisotropy. The internal field in layer ( 13 ) can also be due to an exchange coupling with an adjacent antiferromagnetic layer (not shown) or from a SAF structure (not shown) as discussed above. Electric current ( 19 ) flows within current carrying layer ( 16 ) along Direction 1 and generates a magnetic field to induce a Direction 2 magnetization component in layer ( 13 ). Although the magnetization of layer ( 1 ) is shown along Direction 1 , the current in layer ( 16 ) would also induce a Direction 2 component. During the trapping state, layer ( 13 ) magnetization would be magnetized by the current field of ( 16 ) to have a Direction 2 magnetization component and thereby create surface charges on the Direction 2 (lateral) edges. During the release state, the current generated field of ( 16 ) is turned off and layer ( 1 ) magnetization loses the Direction 2 component and is once again completely aligned with Direction 1 .
Embodiment 1D
Referring to FIG. 12D there is shown schematically a trapping device that is materially and geometrically identical to that in FIG. 12C with the important difference that the magnetization of layer ( 13 ) remains fully aligned with Direction 2 during both the trapping and release states. Electrical current ( 5 ) flows in current path ( 4 ) along Direction 1 and generates a magnetic field to switch the magnetization direction of layer ( 1 ) between the two orientations of Direction 2 . The magnetization of layer ( 1 ) is pinned along Direction 2 by one or a combination of crystalline anisotropy, shape anisotropy, stress induced anisotropy or by a constant current ( 5 ) induced field. The pinning field can also be supplied by exchange coupling to an antiferromagnetic layer beneath the layer ( 1 ) or from a SAF structure (neither being shown). During the trapping state, layer ( 1 ) magnetization of every patterned device is in the same direction except for the particular patterned device that traps the magnetic label. That trapping device has its magnetization switched in a direction opposite to that of its immediately adjacent device. During the release state, all device magnetizations are identical.
2—Transport Method
Embodiment 2A
The physical entities that are transported can be magnetic labels attached to single or multiple molecules or cells. They can also be cells coated with molecules that are themselves attached to multiple magnetic labels. Because of the variety of molecule and cell combinations that can be successfully attached to magnetic labels, we will simply refer to the objects being transported as “test units” for the following descriptions.
The transport of a test unit is preferably, but not limited to, one unit at a time. Transport of the test unit in a given direction is achieved by a spatially separated array of the trapping structures described in FIGS. 12A-12D as embodiments 1A-1D respectively, with the arrays aligned so as to produce transport of a test unit along the given direction or transport route. Referring to FIG. 13A there is shown schematically a simple configuration for test unit transport substantially identical to that in FIG. 10A . An array of parallel magnetic strips ( 13 ) or patterned devices such as any of those shown in FIG. 12A-12D are arranged under the sample pool defined by the confining edges ( 17 ) of the sample pool region. The transport channel is also defined by edges ( 170 ) in this embodiment (but it need not be) and a parallel array of strips ( 13 ), like strips, is formed under the transport channel. The lengths of the strips under the pool and the channel can be different.
Transport of the test units is preferably through the transport channel ( 170 ), which has a length along the transport route significantly longer than the unit size and a width perpendicular to the transport route larger than the size (eg., a diameter) of a single unit but smaller than twice that size. The trapping patterns (i.e. the patterned magnetic structures as described in FIGS. 12A-12D and with possible shape variations of FIG. 12E ) lie beneath the channel with Direction 2 being locally along the route direction for each trapping pattern.
Transport may also be accomplished without the use of a confining channel structure when the cross-route direction trapping pattern width can be adjusted to be small enough to confine one test unit for transport per unit of time. A larger cross-route width of the trapping pattern allows for more test units in such a given time.
Embodiment 2B
Transport of the test units along the array of patterned structures is realized by sequential trapping and releasing of adjacent trapping patterns in the direction of the transport and, in addition, the transport of the test unit is assisted by a temporarily applied external field. When one test unit is trapped by a trapping pattern edge (i.e. the edge of a patterned device that is magnetically oriented to create a trapping situation) an applied magnetic field magnetizes the label or labels attached to the unit so that the unit moves to an adjacent edge of a trapping pattern that provides the unit with a lower magnetic energy. It is noted that the condition of a trapped label can be viewed energetically as being in a position of minimum local magnetostatic energy of the system of label-array. The applied external magnetic field assists in moving the label towards such an energy minimum. By making the adjacent edge towards which the external field moves the label the same edge as that to which the label is to be transported next, when the original trapping pattern is placed in a release state (by resetting its magnetization) and the external field is turned off, the unit moves more easily to the neighboring trapping position with better repeatability.
3—Label Separation by Trapping Pattern
To separate chained magnetic labels by the application of trapping fields, when a first test unit is trapped by a trapping field and where other nearby magnetic labels are chained to that test unit by inter-label magnetic forces, the immediately adjacent label on the second test unit can be made to experience a trapping field from another, more distant array site. This trapping of the second test unit, as shown in FIG. 8A-8D can enable the first test unit to be separated from and transported away from the remaining chained units.
Embodiment 3A
By maintaining the trapping mode of the sites on which the chained test units that are not to be transported are trapped (the chained units being the ones from which the first test unit is to be separated), separation of the first test unit from those chained units and transport of the first test unit towards the target site can be realized by sequential trapping and releasing of the adjacent trapping patterns in the direction of transport. With the site pattern neighboring the first test unit being the target site to which the first test unit is being transported, and with that neighboring site being first turned on to its trapping state and then with the trapping field that currently traps the first test unit being turned off (placed in its release state), the first test unit will move to the neighboring site due to the magnetic field that the unit experiences from the neighboring sites.
Embodiment 3B
By maintaining the trapping mode of the sites on which the chained test units that are not to be transported are trapped (the chained units being those from which the first test unit is to be separated), separation of the first test unit from those chained units and transport of the first test unit towards the target site can be realized with the assist of a temporarily applied external magnetic field. The applied field magnetizes the magnetic labels within each unit so that the first unit and the chained second units move to the lowest magnetostatic energy edges of the trapping patterns that are trapping them. Since the remaining units of the chain are all attached to the immediately adjacent second unit, by making the lowest energy edge where the first unit is being trapped in the presence of the external field, the edge facing the neighboring pattern to which the unit is to be transported next, the unit will experience a higher field from the neighboring pattern when the neighboring pattern is in its trapping state. When the pattern trapping the first unit is placed in its release state and the neighboring pattern is placed in a trapping state and the applied field is turned off, the first unit moves to the neighboring trapping pattern and can then be transported away from the remaining units of the chain.
4—Label Collection and Guided Concentration
Embodiment 4A
Referring again to FIG. 13A , there is shown schematically a liquid-form biological sample solution containing test units, which are labeled biological entities ( 4 ) to which magnetic labels are attached. The solution may also contain unattached labels ( 8 ). This solution is deposited into a planar but confined sample pool ( 17 ). The sample pool ( 17 ) has a funnel-shaped structure ( 190 ) which is denoted a concentration region. This region may or may not be tapered, although it is shown here with the funnel shape. The funnel structure leads to a narrow transport channel ( 170 ) within which test units ( 4 ) and unattached labels ( 8 ) are transported. The sample pool, the funnel structure and the transport channel all have bottom surfaces for confining the solution. Typically, they also have edges along their perimeters to assist in confining the solution. As already noted, however, the channel region need not have confining edges.
Beneath the bottom surface of the channel is an array ( 13 ) of parallel trapping structures which may be an array of parallel, closely spaced patterned magnetic thin film strips underlaid with current carrying leads or other devices and structures of the type previously discussed. Beneath the bottom surface of ( 17 ) and ( 190 ) there are also arrays ( 13 ) similar to those under the channel, but of greater length than those under the channel so as to stretch across the width of ( 17 ) and ( 190 ). Thus, when ( 13 ), beneath ( 190 ) is switched to a trapping state at an appropriate location, it attracts test units from the solution pool. With a continuous application of sequentially switched trapping states, the test units can be progressively moved from the pool ( 17 ) into the funnel shaped region ( 190 ) and finally into the channel ( 170 ), where they move along on a one-by-one basis.
Embodiment 4B
Referring to FIG. 13B , there is shown schematically a system of multiple funnel shaped structures ( 90 ), ( 91 ) and ( 92 ), each identical to the single structure of FIG. 13A and each terminating into its own transport channel ( 161 ), ( 162 ), ( 163 ). A common set of patterned trapping structures ( 13 ) traverse the bottom surfaces of the structures and permits a synchronized transport of test units towards the channels. Beneath each transport channel is a patterned set of trapping structures like ( 13 ) that can be independently activated so that transport within each channel is parallel and independent.
5—Signal Detection and Sample Sorting
Embodiment 5A
Referring to FIG. 14A , there is shown schematically a process by which optical detection of the optical signal generated by the luminescent/fluorescent dyes attached to the biological cells or molecules is performed within the transport channel ( 170 ) of a structure (magnetic strips not shown) such as that shown schematically in FIG. 13A . The required excitation light (( 22 ) from opposite side or ( 222 ) from same side as the detector ( 11 )) to induce the response of the dye on an exemplary object ( 187 ) is passed through excitation optics ( 122 ) and illuminates a small section of the transport channel, which is transparent to the light. The size of the illuminated region is preferably no larger than a size in which at most two units could appear at the same time. The detection optics ( 110 ) transmits the optical signal from the illuminated region to a detector ( 11 ). Thus, when test units pass through the detection optics, signal peaks can be generated by the detector as discussed previously in FIG. 11B . The excitation and detection optics can also be partly or entirely constructed of fiber-optics elements.
Embodiment 5B
Referring to FIG. 14B , there is shown schematically test units ( 7 ) passing through the transport channel ( 170 ) and reappearing in a second collection pool ( 16 ). Subsequent to the arrival of the test units into pool ( 161 ), the emitted excitation light reaches the detector ( 11 ) from the illuminated collected units in the pool and an optical signal is received that can be correlated to the population of units in the pool. In this way, when a conventional 2D optical image of the sample pool ( 161 ) is taken, or an optical signal amplitude-to-population correlation is performed, existence and population of the target molecules or cells can be estimated without the interference of the sample solution and unbound optical dyes within the initial sample pool ( 500 ). In this method the units need not be transported individually through the channel ( 170 ).
Embodiment 5C
Referring to FIG. 14C , there is shown schematically a configuration wherein the region of optical detection is at an intersecting crossing ( 20 ) of different transport pathways ( 170 ) and ( 99 ). A trapping island ( 66 ), shown in inset ( 25 ), is formed by a patterned device ( 66 ) such as that in FIG. 12A under which are two electrical current paths ( 166 ), ( 177 ), which can magnetize the device in either of two different perpendicular directions. Different magnetically labeled biological entities can be labeled with different optical dyes. When transported into the island region, depending on the optical signal generated and detected by optics ( 110 ) and ( 11 ) as in FIG. 14B , different entities can both be counted and then can be shunted into different transport channels thereby achieving a sorting of the test units or a segregation of the units into separate pools.
As is finally understood by a person skilled in the art, the preferred embodiments of the present invention are illustrative of the present invention rather than limiting of the present invention. Revisions and modifications may be made to methods, materials, structures and dimensions employed in forming, providing and using an array of trapping/releasing patterned devices that can guide and transport magnetically and optically labeled cells and molecules so that they can be detected on an individual basis, while still forming, providing and using such an array in accord with the spirit and scope of the present invention as defined by the appended claims. | Presented herein is a method and devices for identifying biological molecules and cells labeled by small magnetic particles and by optically active dyes. The labeled molecules are typically presented in a biological fluid but are then magnetically guided into narrow channels by a sequential process of magnetically trapping and releasing the magnetic labels that is implemented by sequential synchronized reversing the magnetic fields of a regular array of patterned magnetic devices that exert forces on the magnetic particles. These devices, which may be bonded to a substrate, can be formed as parallel magnetic strips adjacent to current carrying lines or can be substantially of identical structure to trilayered MTJ cells. Once the magnetically labeled molecules have been guided into the appropriate channels, their optical labels can be detected by a process of optical excitation and de-excitation. The molecules are thereby identified and counted. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to and claims the benefit of, under 35 U.S.C. § 119(e), U.S. Provisional Patent Application Serial No. 60/306,463, filed 20 Jul. 2001, which is expressly incorporated fully herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to light-weight thin-film photovoltaic cells, methods for making cells, modules made from cells, and methods for making modules from cells. The invention teaches a manner in which individual cells may be bonded to one another, eliminating the need for an additional support substrate and interconnecting leads, thus reducing the overall weight and thickness of individual cells and modules of cells.
[0004] 2. Description of the Prior Art
[0005] The prior art method of producing thin-film photovoltaic cell devices includes bonding individual cells onto a load-bearing substrate sheet such as Kapton®. This load bearing substrate, together with the leads necessary to electrically connect individual cells, contributes to the overall weight of the device. This additional weight and thickness is particularly undesirable in space applications.
[0006] Currently, two barriers to implementing thin-film photovoltaic cell devices in space applications are difficulty obtaining large areas of photovoltaic material deposited on a light-weight substrate and difficulty forming light-weight space-survivable interconnects between individual cells in an array.
SUMMARY OF THE INVENTION
[0007] The present invention provides, for example, reduced weight solar cells, of particular importance in extraterrestrial applications, by providing a method of bonding individual cells to one another. The present invention also provides, for example, integrated interconnects which may also be easier and cheaper to manufacture.
[0008] It is an object of the present invention to provide a light-weight photovoltaic device and a method for its manufacture. This is accomplished by providing a non-fragile insulator layer supporting a weld or bonded contact. This non-fragile layer permits two or more of the light-weight photovoltaic devices to be connected without requiring an additional support layer. In addition, connecting the individual photovoltaic devices together further decreases the weight because it eliminates the needs for electrical leads between the individual cells. It is a further object of the present invention to provide a thin photovoltaic device and method for its manufacture. This is accomplished by eliminating the need for an additional support layer, by substituting non-fragile insulator for a portion of the photoactive layer. This insulator layer provides non-fragile support for weld or bonded contacts, allowing individual photovoltaic devices to bonded to each other rather than requiring an additional support layer.
[0009] It is a further object of the invention to provide a method of producing thin-film solar arrays that may be much lighter per unit of power than existing single crystal solar cell arrays. Moreover it is an object of the present invention to further reduce the weight of solar arrays by reducing the structure required to support a thin-film blanket. Additionally, it is an object of the present invention to provide a solar array that may be contained with lower-weight hardware during launch.
[0010] In one embodiment of the present invention, a cell may be constructed beginning with a substrate. This substrate may, for example, be a rectangular plate. Preferably, the substrate may be a polygon which defines the shape of the photovoltaic cell, including a photoactive area and an electrical bus. The electrical bus may be a series of triangles connected at their bases by a narrow rectangle. Preferably the center of these triangular regions may be the location of weld or bond contacts. The substrate may, for example, be formed from stainless steel, titanium, tantalum, Kovar®, molybdenum, polyimide, or Kapton®. The preferred material is stainless steel. A photoactive layer may be deposited on this substrate. This photoactive layer, may, for example, comprise a photovoltaic device. This photovoltaic device may preferably comprise a cadmium-indium-gallium-diselinide (CIGS) device. The photoactive layer may cover a portion of one side of the substrate. Preferably the layer should define a region, or a plurality of regions, for use as weld or bond contact points. In one embodiment of the present invention, the defined regions may include the triangular portions of the substrate, and corresponding areas on the opposite side and at the opposite end of the substrate. One method by which these regions may be defined is by applying the photoactive layer to a substantial portion of the substrate.
[0011] Next, the area where the photoactive layer is desired may be masked. This masking may, for example, be accomplished by means of low adhesion tape or metal contact mask. Next, an etching solution may be applied to the device to etch the unmasked areas down to the substrate. The etching solution may preferably be HCl followed by Br/MeOH. Following the etching process, the mask may be removed. Alternatively, the desired areas may be etched using, for example, electro-decomposition, laser ablation, or bead blasting.
[0012] Another way to define the shape of the photoactive layer is to place physical contact masks over the desired areas prior to deposition of the photoactive layer; however, other photolithographic techniques are not precluded. Additionally, if the photoactive layer is grown by applying precursor layers, these precursor layers may be applied to define the desired areas.
[0013] The photoactive layer may, for example, alternatively comprise amorphous silicon, cadmium telluride, or thin-film silicon. The photoactive layer may be applied, for example, by thermal evaporation, sputtering, or electron-beam evaporation.
[0014] Next, a layer of insulator may be applied to the substrate. The insulator layer may preferably be applied to the areas of the substrate on the same side as the photoactive layer that are not covered by the photoactive layer, including, for example, areas from which portions of the photoactive layer have been etched. The insulator may, for example, comprise silicon dioxide, aluminum nitride, alumina, silicon nitride, or adhesive bonding agents. The preferred material is silicon dioxide, or an adhesive bonding material. The insulator may preferably be applied by plasma enhanced chemical vapor deposition. The insulator may also be applied, for example, by sputtering.
[0015] Next, a grid may be applied to the photovoltaic device and first insulator layer. This grid may preferably comprise a conductor. This conductor may preferably comprise a metal, preferably aluminum or silver. Other metals or conductors are not precluded, however, it is preferable that the material for the grid have a low sheet resistance. The grid may preferably truncate in a bus. This bus may, for example, comprise an area covering the triangular-shaped region of the insulator layer. The shape of the bus, and consequently the shape chosen for the underlying substrate, is not required to be triangular. A triangular shape, however, will provide good electrical characteristics without providing as much weight as, for example, a completely rectangular-shaped bus. Other shapes are not precluded. The grid may preferably be applied by electron-beam deposition. Other techniques for applying the grid include, for example, thermal evaporation and screen printing.
[0016] Finally, weld contacts may be applied to the weld contact points. The weld contact points may preferably be located in the triangular areas of the bus, and in corresponding locations at the opposite end, and reverse side of the cell. The weld contacts may comprise a conductor. Preferably, this conductor comprises a metal, such as, for example, silver. It is valuable for the weld contact to be formed of a material that has good ductility at low temperature. It is of additional value, in certain applications, for the material to resist work hardening after thermal cycling. The weld contacts may preferably be applied by electro-deposition. Other available techniques, for example, include thermal evaporation and sputtering.
[0017] Additionally, if desired, a second layer of insulator may be added to the top and bottom surfaces of the cell, exclusive of the weld contacts or weld contact points. This insulator layer may have the beneficial result of reducing the operating temperature of the cell by increasing the emissivity and decreasing the absorptivity of the device.
[0018] Furthermore, an electro-static discharge layer may be added to each side of the device. If no insulator layer has been added to a side of the device, other layers, including, for example, the photoactive layer and the substrate layer, may perform the function of an electro-static discharge layer. Moreover, if, for example, an electrostatic discharge layer is completely covered by an insulator layer, its function as an electro-static discharge layer may not be optimal. The electro-static discharge layer may preferably be applied to substantially the same area of the cell as the second layer of insulator. The electro-static discharge layer may, for example, comprise indium tin oxide, tin oxide, cadmium tin oxide, or zinc oxide. Some techniques for applying the electro-static discharge layer include, for example, sputtering, electron-beam evaporation, and thermal evaporation. The preferred technique is sputtering, but other techniques are not precluded. The addition of an electro-static discharge layer is not required, but may be desirable if the cell will be used in a high plasma environment. The layer may have the beneficial effect of bleeding off charge, thus avoiding sparking and consequent damage to the cell.
[0019] These above described steps may provide an individual cell. Modules of these cells may be formed by, for example, bonding two or more individual cells together. The bonding may, for example, comprise bonding the weld contacts of one side of one cell to the weld contacts of one side of another cell. The sides may be alternated, providing a shingling effect. This may have the desirable effect of shadowing only the bus, and not the photoactive portions of the cell. The bonding may preferably comprise spot welding. Other techniques may, for example, include soldering or brazing. The bonding may, for example, be accomplished by spot welding, or by any other standard metal-to-metal bonding technique, such as brazing, soldering, and additional forms of welding. Although one pair of weld contacts will permit the bonding of multiple individual cells, it may be preferable to use three or more pairs to ensure that the strength of the module is not compromised if one of the weld contacts fails.
[0020] Alternatively, the strength of the module may be enhanced by the addition of one or mechanical bonds (for example, adhesive bonds) between a pair of cells in the module. This bond may be provided directly between the cells or may be provided through one or more apertures in a spacer. The spacer may, for example, include a rectangular sheet of polyimide. The sheet of polyimide may be adapted to allow the electrical bond or bonds and the mechanical bond or bonds to pass through it. The mechanical bonds may be chosen to be an insulating material. If a spacer is used, it may be advantageous to supply it with slits adapted to relieve mechanical stresses placed on it. A further alternative is to supply a single mechanical bond that occupies a significant area. This mechanical bond may contain an embedded insulating mesh, insulating scrim, or insulating beads.
[0021] It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a diagram of a cross section of a preferred embodiment of the present invention.
[0023] [0023]FIG. 2 a is a top view diagram of a section of a preferred embodiment of the present invention.
[0024] [0024]FIG. 2 b is a top view diagram of a section of a preferred embodiment of the present invention.
[0025] [0025]FIG. 2 c is a top view diagram of a section of a preferred embodiment of the present invention.
[0026] [0026]FIG. 2 d is a bottom view diagram of a preferred embodiment of the present invention.
[0027] [0027]FIG. 3 is a conceptual flow diagram of a preferred embodiment of the present invention.
[0028] [0028]FIG. 4 is a top view partial look-through diagram of a preferred embodiment of the present invention.
[0029] [0029]FIG. 5 is a conceptual flow diagram of a preferred embodiment of the present invention.
[0030] [0030]FIG. 6 is a diagram of an embodiment of the present invention employing additional mechanical connections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] It is to be understood that the present invention is not limited to the particular methodology, compounds, materials, manufacturing techniques, uses, and applications, described herein, as these may vary. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a layer” is a reference to one or more layers and includes equivalents thereof known to those skilled in the art, unless otherwise necessarily dictated by the context of the description. For example, the photoactive layer may comprise a plurality of layers, including layers that are not, in themselves, photoactive, such as, for example a transparent conductive oxide layer or a substrate layer. Moreover, the application of one layer to another is sometimes referred to herein by the term deposition. This term is meant to include non-traditional depository methods of joining two layers, including, for example, but not limited to ceramic-ceramic bonding of two existing layers. Additionally, while three pairs of weld contacts for each cell may have the beneficial result of providing redundant resistance to twisting, the number of pairs of weld contacts is only an example.
[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Preferred methods, techniques, devices, and materials are described, although any methods, techniques, devices, or materials similar or equivalent to those described herein may be used in the practice or testing of the present invention. All references cited herein are incorporated by reference herein in their entirety.
[0033] In one embodiment of the present invention, a photovoltaic device is provided on a light-weight substrate. The device and substrate may be generally planar and may be referred to as a sheet or panel. The photovoltaic device may, for example, be a copper-indium-gallium-selenide (CIGS) photovoltaic device. The substrate may be, for example, an approximately 0.001 in. thick substrate, and may be stainless steel. In this embodiment, a grid is then deposited on one side of the sheet (the face of the sheet). The grid may include several layers. For example, it may include a strike layer, a conductive layer, and a protective layer. Frequently, although one layer is herein described as the conductive layer, all of the layers may be conductive. The strike layer may, for example, comprise a 500 Angstrom layer of Titanium. The conductive layer may comprise, for example, a 2 micron layer of silver. The protective layer may, for example, comprise a 500 Angstrom layer of Nickel. A thermal coating may be applied to the device including the grid. This thermal layer may comprise, for example, SiO 2 . This coating may be deposited by means of a plasma enhanced chemical vapor deposition process. The thickness of this coating may be about 5 microns. Thermal coating may also be applied over a layer of silver on the side of the sheet opposite the grid (the reverse of the sheet). An electro-static discharge (ESD) layer may be applied over the thermal coating. The ESD layer may include indium tin oxide and may be approximately 600 Angstroms thick. The ESD layer may be connected to one or more of the electrical contacts. Preferably the portion of the ESD layer on the same side as the grid may be connected to the electrical contacts on that side of the sheet, and the portion of the ESD layer on the reverse of the sheet may be connected to the electrical contacts on that side of the sheet. This connection may provide the advantage of allowing charge to enter the circuit passing through the cell.
[0034] [0034]FIG. 1 depicts a preferred embodiment of an apparatus of the present invention. The apparatus, for use as a photovoltaic cell, comprises at its core a layer of substrate ( 110 ). This substrate ( 110 ) may preferably comprise stainless steel. The substrate ( 110 ) may also or alternatively include other materials such as, for example, titanium, tantalum, Kovar®, molybdenum, polyimide, and Kapton®. On the substrate ( 110 ) a layer of photoactive material ( 120 ) may be deposited. The photoactive layer ( 120 ) may comprise a photovoltaic device, such as, for example, a copper-indium-gallium-diselinide (CIGS) device. The photoactive layer ( 120 ) may also or alternatively include other materials such as, for example, amorphous silicon, cadmium telluride, and thin-film silicon. The photoactive layer ( 120 ) may be deposited, for example, by thermal evaporation, sputtering, or electron-beam evaporation. The shape of the photoactive layer ( 120 ) may be defined by removing a portion of the applied layer, by laser etching, chemical etching, or bead blasting material from the substrate ( 110 ) or by other techniques including, for example, photolithography, placing a physical contact mask on the substrate ( 110 ) during the deposition of the photoactive layer ( 120 ), by patterning precursors to the photoactive layer ( 120 ) to define the desired shape, or by laser etching the material from the substrate.
[0035] On a portion of the remaining exposed upper surface of the substrate ( 110 ) a first layer of insulator ( 130 ) may be deposited. This first layer of insulator ( 130 ) may preferably comprise silicon dioxide. The first layer of insulator ( 130 ) may also or alternatively comprise other materials including, for example, aluminum nitride, alumina, silicon nitride, or bonded polyimide. The first layer of insulator ( 130 ) may preferably be deposited by plasma enhanced chemical vapor deposition. Other techniques, such as, for example, sputtering, are not precluded.
[0036] On the first layer of insulator ( 130 ), and on the photoactive layer ( 120 ), a grid ( 140 ) may be deposited. The grid ( 140 ) may preferably comprise a bus. The bus may, preferably, cover the first layer of insulator ( 130 ). The grid ( 140 ) may comprise a conductor, preferably a metal, most preferably aluminum or silver. Other conductors which preferably exhibit low sheet resistance may also be suitable. The grid ( 140 ) may, for example, be deposited by electron-beam deposition. Other techniques that may be used include, for example, thermal evaporation, sputtering, and screen printing.
[0037] If desired, on the grid ( 140 ) and on the bottom of the substrate ( 110 ), a second layer of insulator ( 150 ) may be deposited. The second layer of insulator ( 150 ) preferably may provide clearance for the weld contacts ( 170 ). This second layer of insulator ( 150 ), if deposited, may have the beneficial result of increasing emissivity, and lowering absorptivity, thus reducing the operating temperature of the device.
[0038] Additionally, if desired, an electrostatic discharge layer ( 160 ) may be deposited on (or in place of) the second layer of insulator ( 150 ), although in the absence of the second layer of insulator ( 150 ), the grid ( 140 ), the photoactive layer ( 120 ), and the substrate ( 110 ) may provide the function of an electro-static discharge layer ( 160 ). The electro-static discharge layer ( 160 ) may, for example, comprise indium tin oxide, tin oxide, cadmium tin oxide, or zinc oxide. A beneficial result may accrue from the deposition of the electro-static discharge layer ( 160 ), namely that the layer ( 160 ) may bleed off charge, preventing sparking and consequent damage to the device.
[0039] Finally, one may deposit weld contacts ( 170 ) to each side of the cell. These weld contacts ( 170 ) may comprise silver. Other conductors, and in particular, other metals, are not precluded; however, silver is the preferred material because it is ductile at low temperatures and will not work harden while undergoing thermal cycling. The weld contacts ( 170 ) may be preferably applied by electron-deposition. Other techniques, such as, for example, thermal evaporation and sputtering are not precluded.
[0040] [0040]FIGS. 2 a , 2 b , 2 c , and 2 d depict various stages in the manufacture of a preferred embodiment of the present invention. FIG. 2 a depicts the substrate ( 2110 ) and photoactive layers ( 2120 ). The photoactive layer ( 2120 ) may be deposited as shown, or may be deposited more extensively and etched back to what is shown. FIG. 2 b depicts the device after the deposition of the grid ( 2240 ). The photoactive layer ( 2120 ) may be partially or incompletely covered by the grid ( 2240 ). If the grid ( 2240 ) comprises an opaque material (opaque in the frequency range used by the photoactive layer( 2120 )), the grid ( 2240 ) should not completely cover the photoactive layer ( 2120 ). Additionally, the area that grid ( 2240 ) covers (including gaps between grid lines) should preferably partially or incompletely correspond to the photoactive layer ( 2120 ). The grid ( 2240 ) at the top may completely cover the layer of insulator under, for example, a triangularly shaped bus. A portion of the substrate ( 2110 ) may remain exposed. FIG. 2 c shows the device after the deposition of the insulator ( 2350 ) and/or electrostatic discharge layers ( 2360 ). A portion of the grid ( 2240 ) may remain exposed, as may a portion of the substrate ( 2110 ). These exposed areas ( 2110 , 2240 ) may provide clearance for the deposition of weld contacts. The weld contacts on the top surface of the device may preferably be located on the exposed grid ( 2240 ). FIG. 2 d depicts the bottom of the device. The insulator and/or electrostatic layers ( 2340 , 2360 ) may be applied to cover substantially the entire surface of the device. These layers ( 2350 , 2360 ) may define weld contact points ( 2470 ) corresponding to the exposed areas on the top surface of the device. The weld contact points ( 2470 ) may serve as the area of deposition of the weld contacts.
[0041] [0041]FIG. 3 portrays a conceptual flow diagram of a preferred embodiment of the present invention. One may begin by providing a substrate ( 310 ) comprising, for example, stainless steel. Other materials for use as a substrate include, for example, titanium, tantalum, Kovar®, molybdenum, polyimide, and Kapton®. One may deposit a photoactive layer ( 320 ) on the substrate. This photoactive layer may comprise a photovoltaic device, such as, for example, a copper-indium-gallium-diselinide device. Other materials for use as a photoactive layer include, for example, amorphous silicon, cadmium telluride, and thin-film silicon. The deposition of this layer may be accomplished, for example, by thermal evaporating, sputtering, or electron-beam deposition.
[0042] Next, the shape of the photoactive layer may be defined by, for example, etching. This may be accomplished by masking the areas on which one does not desire to etch ( 324 ) and etching the remaining unmasked areas ( 328 ). This masking ( 324 ) may be accomplished by, for example, the application of low adhesion tape. The etching may, for example, be accomplished by applying a solution of HCl followed by a solution of Br/MeOH. Alternatively, the etching may be performed by laser ablation or bead blasting.
[0043] When the photoactive layer is defined, a layer of insulator may be deposited on a portion of the exposed substrate ( 330 ). The insulator may comprise, for example, silicon dioxide. Other materials which may be used as an insulator include, for example, aluminum nitride, alumina, and silicon nitride. The insulator may for example, be deposited by plasma enhanced chemical vapor deposition, or by other techniques, such as, for example, sputtering.
[0044] Next, a grid may be deposited on the insulator and photoactive layers ( 340 ). This grid may comprise a bus which covers a substantial portion of the insulator layer. The grid may comprise aluminum, silver, or any other conductor. The use of aluminum or silver in the grid may be particularly beneficial because of their low sheet resistances.
[0045] Next, if desired, a second layer of insulator may be added covering most of the device ( 350 ). The second layer of insulator should, preferably, provide clearance for the weld contacts. The second layer of insulator may also provide the beneficial result of increasing emissivity and lowering absorptivity, thus lowering the operating temperature of the device.
[0046] Additionally, if desired, an electro-static discharge layer ( 360 ) may be added. This layer may, for example, comprise indium tin oxide, tin oxide, cadmium tin oxide, or zinc oxide. The adding of this electro-static discharge layer may be accomplished by, for example, sputtering, or by other techniques, such as, for example, thermal evaporation or electron-beam evaporation.
[0047] Finally, one may deposit weld contacts ( 370 ) to each side of the cell. The weld contacts may, for example, comprise silver. Other materials are not precluded, however, silver's ability to withstand work hardening in temperature cycling environments, together with its ductility at low temperature make it a preferred material. The weld contacts may, for example, be deposited by electron-deposition. Other techniques which may be used include, for example, thermal evaporation and sputtering.
[0048] [0048]FIG. 4 is a top view partial look-through diagram of a preferred embodiment of the present invention. A first photovoltaic cell ( 480 ) is connected to a second photovoltaic cell ( 490 ) by means of the weld contacts ( 470 ). This connecting may, for example, be performed by spot welding. Other techniques may also be used for connecting photovoltaic cells, including, for example, soldering and brazing. The dotted line depicts the hidden outline of the second cell ( 480 ).
[0049] [0049]FIG. 5 is a conceptual flow diagram of a preferred embodiment of the present invention. One may begin with a first photovoltaic cell ( 510 ). Next, a second photovoltaic cell ( 520 ) may be attached to the first photovoltaic cell ( 510 ). This attaching may, for example, be accomplished by spot welding, or may comprise other techniques such as, for example, soldering, brazing, or adhesive bonding. The cells may be attached so that the bus of the second cell is shadowed by the first cell. If this is the last cell in the desired module ( 530 ), then the process is complete ( 540 ), otherwise, one may repeat the step of adding a cell ( 520 ) until complete ( 540 ).
[0050] [0050]FIG. 6 is a diagram of an embodiment of the present invention employing additional mechanical connections. This embodiment may have the advantage of reducing the mechanical reliance of the apparatus on the electrical bond 6240 between the photovoltaic device layers and a molybdenum layer. In some instances, an MoSe 2 layer may form at the junction between the photovoltaic device and a molybdenum layer. An MoSe 2 layer may possess a highly layered structure.
[0051] As depicted in the embodiment shown in FIG. 6, a polyimide spacer 6630 may be applied on top of the area of the substrate that is not photoactive. In this embodiment, a spacer 6630 may be adapted in several ways. First, several circular apertures may be provided to permit the introduction of mechanical bonds 6610 through the spacer 6630 . Next, several square apertures may be provided to permit electrical connections 6240 through the spacer 6630 . The shapes of these apertures are exemplary only. There is no need to use the particular shapes described. Finally, several sets of narrow rectangular slits 6620 may be provided. These slits 6620 relieve mechanical stress placed on the polyimide spacer 6630 by such forces as thermal compression and expansion, and may prevent the fracture, loss, or separation of polyimide spacer 6630 . If, as shown, the mechanical bonds connect the top of a first substrate with the bottom of an overlapping substrate, it may be desirable to use an insulating material in the mechanical bonds. It may also be desirable to minimize the size of each mechanical bond's area. This may be accomplished, in part, by increasing the number of mechanical bonds while decreasing the area of each mechanical bond. A reduced area for each mechanical bond may provide greater survivability at temperature extremes. It may be advantageous (based on considerations of structural integrity) to minimize the size of the electrical bonds 6240 , while maintaining at least a minimum area to prevent the introduction of significant electrical resistance.
[0052] Alternatively, in an embodiment not depicted, a large mechanical bond may substitute for the spacer 6630 and small mechanical bonds 6610 . The large mechanical bond may include bonding material intermixed with a glass scrim, glass beads, or other insulating material. This added material may improve the ability of the bond to maintain insulating properties after the stresses of thermal cycling.
[0053] Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and the practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. | The present invention relates to light-weight thin-film photovoltaic cells, methods for making cells, modules made from cells, and methods for making modules from cells. The invention teaches a manner in which individual cells may be bonded to one another, eliminating the need for an additional support substrate and interconnecting leads, thus reducing the overall weight and thickness of individual cells and modules of the cells. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/209,567 filed on Jul. 30, 2002 and claims priority under 35 U.S.C. 119 of Danish application PA 1999 00536 filed on Apr. 20, 1999, of U.S. Provisional application 60/132,636 filed on May 5, 1999 and of PCT/IB99/00681 filed on Apr. 16, 1999, and the benefit of application Ser. No. 09/550,843 filed on Apr. 17, 2000 in the U.S. is claimed under 35 U.S.C. 120., the contents of which are fully incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparations and its use as therapeutic agents. More specifically the present invention relates to crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, preferably (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparation and its use as therapeutic agent.
BACKGROUND OF THE INVENTION
[0003] Coronary artery disease (CAD) is the major cause of death in type 2 diabetic and metabolic syndrome patients (i.e. patients that fall within the ‘deadly quartet’ category of impaired glucose tolerance, insulin resistance, hypertriglyceridaemia and/or obesity).
[0004] The hypolipidaemic fibrates and antidiabetic thiazolidinediones separately display moderately effective triglyceride-lowering activities although they are neither potent nor efficacious enough to be a single therapy of choice for the dyslipidaemia often observed in type 2 diabetic or metabolic syndrome patients. The thiazolidinediones also potently lower circulating glucose levels of type 2 diabetic animal models and humans. However, the fibrate class of compounds are without beneficial effects on glycaemia. Studies on the molecular actions of these compounds indicate that thiazolidinediones and fibrates exert their action by activating distinct transcription factors of the peroxisome proliferator activated receptor (PPAR) family, resulting in increased and decreased expression of specific enzymes and apolipoproteins respectively, both key-players in regulation of plasma triglyceride content. Fibrates, on the one hand, are PPARα activators, acting primarily in the liver. Thiazolidinediones, on the other hand, are high affinity ligands for PPARγ acting primarily on adipose tissue.
[0005] Adipose tissue plays a central role in lipid homeostasis and the maintenance of energy balance in vertebrates. Adipocytes store energy in the form of triglycerides during periods of nutritional affluence and release it in the form of free fatty acids at times of nutritional deprivation. The development of white adipose tissue is the result of a continuous differentiation process throughout life. Much evidence points to the central role of PPARγ activation in initiating and regulating this cell differentiation. Several highly specialised proteins are induced during adipocyte differentiation, most of them being involved in lipid storage and metabolism. The exact link from activation of PPARγ to changes in glucose metabolism, most notably a decrease in insulin resistance in muscle, has not yet been clarified. A possible link is via free fatty acids such that activation of PPARγ induces Lipoprotein Lipase (LPL), Fatty Acid Transport Protein (FATP) and Acyl-CoA Synthetase (ACS) in adipose tissue but not in muscle tissue. This, in turn, reduces the concentration of free fatty acids in plasma dramatically, and due to substrate competition at the cellular level, skeletal muscle and other tissues with high metabolic rates eventually switch from fatty acid oxidation to glucose oxidation with decreased insulin resistance as a consequence.
[0006] PPARα is involved in stimulating β-oxidation of fatty acids. In rodents, a PPARα-mediated change in the expression of genes involved in fatty acid metabolism lies at the basis of the phenomenon of peroxisome proliferation, a pleiotropic cellular response, mainly limited to liver and kidney and which can lead to hepatocarcinogenesis in rodents. The phenomenon of peroxisome proliferation is not seen in man. In addition to its role in peroxisome proliferation in rodents, PPARα is also involved in the control of HDL cholesterol levels in rodents and humans. This effect is, at least partially, based on a PPARα-mediated transcriptional regulation of the major HDL apolipoproteins, apo A-I and apo A-II. The hypotriglyceridemic action of fibrates and fatty acids also involves PPARα and can be summarised as follows: (I) an increased lipolysis and clearance of remnant particles, due to changes in lipoprotein lipase and apo C-III levels, (II) a stimulation of cellular fatty acid uptake and their subsequent conversion to acyl-CoA derivatives by the induction of fatty acid binding protein and acyl-CoA synthase, (III) an induction of fatty acid β-oxidation pathways, (IV) a reduction in fatty acid and triglyceride synthesis, and finally (V) a decrease in VLDL production. Hence, both enhanced catabolism of triglyceride-rich particles as well as reduced secretion of VLDL particles constitutes mechanisms that contribute to the hypolipidemic effect of fibrates.
[0007] A number of compounds have been reported to be useful in the treatment of hyperglycemia, hyperlipidemia and hypercholesterolemia (U.S. Pat. No. 5,306,726, PCT Publications nos. WO 91/19702, WO 95/03038, WO 96/04260, WO 94/13650, WO 94/01420, WO 97/36579, WO 97/25042, WO 95/17394, WO 99/08501, WO 99/19313 and WO 99/16758).
SUMMARY OF THE INVENTION
[0008] It seems more and more apparent that glucose lowering as a single approach does not overcome the macrovascular complications associated with type 2 diabetes and metabolic syndrome. Novel treatments of type 2 diabetes and metabolic syndrome must therefore aim at lowering both the overt hypertriglyceridaemia associated with these syndromes as well as alleviation of hyperglycaemia.
[0009] The clinical activity of fibrates and thiazolidinediones indicates that research for compounds displaying combined PPARα and PPARγ activation should lead to the discovery of efficacious glucose and triglyceride lowering drugs that have great potential in the treatment of type 2 diabetes and the metabolic syndrome (i.e. impaired glucose tolerance, insulin resistance, hypertriglyceridaemia and/or obesity).
[0010] Within one aspect, the present invention provides crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate (pure or substantially pure), wherein R is defined as straight or branched alkyl, straight or branched alkenyl, or straight or branched alkynyl, each of which is optionally substituted with one or more halogen(s), —OH, —CF 3 , —CN, C 1-4 -alkoxy, C 1-4 -alkylthio, —SCF 3 , —OCF 3 , —CONH 2 , —CSNH 2 , NH 2 or COOH.
[0011] In a preferred embodiment R is straight or branched alkyl optionally substituted with NH 2 and COOH.
[0012] In another preferred embodiment, R is straight or branched alkyl.
[0013] Within another aspect, the present invention provides crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate (pure or substantially pure).
[0014] Within another aspect, the present invention provides crystalline (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate (pure or substantially pure).
[0015] Within another aspect, the invention there is provided pharmaceutical compositions comprising crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate optionally in combination with a pharmaceutically acceptable carrier or diluent.
[0016] Within another aspect of the invention there is provided pharmaceutical composition comprising crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate optionally in combination with a pharmaceutically acceptable carrier or diluent.
[0017] Within another aspect of the invention there is provided pharmaceutical composition comprising crystalline (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate optionally in combination with a pharmaceutically acceptable carrier or diluent.
[0018] Within another aspect of the invention there is provided a process for the preparation of crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding an R-guanidine in crystal form, as a suspension or dissolved in an appropiate solvent or a mixture of solvents and crystallizing the resulting salt from the solution.
[0019] Within another aspect of the invention there is provided a process for the preparation of crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding Arginine in crystal form, as a suspension or dissolved in an appropiate solvent or a mixture of solvents and crystallizing the resulting salt from the solution.
[0020] Within another aspect of the invention there is provided a process for the preparation of crystal-line (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding (L)-Arginine in crystal form, as a suspension or dissolved in an appropiate solvent or a mixture of solvents and crystallizing the resulting salt from the solution.
[0021] Within another aspect of the present invention there is provided a method of using the compounds according to the invention for the treatment and/or prevention of diabetes and/or obesity.
DETAILED DESCRIPTION OF THE INVENTION
[0022] Accordingly, the present invention relates to crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate.
[0023] Further, the present invention relates to crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate.
[0024] Further, the present invention relates to crystalline (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, hereinafter called compound I.
[0025] The present invention also relates to a process for the preparation of the above said novel compounds with advantageous physico-chemical characteristics compared to the free acid, and pharmaceutical compositions containing the compounds.
[0026] However, for commercial use it is important to have a physiologically acceptable salt with good stability, non-hygroscopicity, high melting point, high degree of crystallinity, good bioavailability, good handling properties and a reproducible crystalline form.
[0027] The free acid of this salt, (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid shows some pharmaceutically undesirable properties when looking for a suitable way of formulating the drug. It has a low melting point at around 88° C., undergoes a phase transformation at around 75° C. and is sparingly soluble in aqueous media. For the choice of a tablet formulation process it would be a big advantage to have a salt with a higher melting point and without phase transformation, that might be initiated by the tablefting process.
[0028] However, the (L)-Arginine salt was found to have advantageous physico-chemical characteristics that will significantly ease the formulation process. It has a high melting point at around 181° C., is highly stable, not hygroscopic even at relative humidities as high as 90 RH, shows a high degree of crystallinity, good bioavailability due to a significantly higher aqueous solubility, good handling properties, and appears in a reproducible crystalline form. Accordingly, the present invention provides compound I as a novel material, in particular in pharmaceutically acceptable form.
[0029] The present invention also provides a process for the preparation of crystalline R-guanidines of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding an R-guanidine in crystal form, as a suspension or dissolved in an appropiate solvent or a mixture of solvents and crystallizing the resulting salt from the solution.
[0030] The present invention also provides a process for the preparation of crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding Arginine in crystal form, as a suspension or dissolved in an appropiate solvent or a mixture of solvents and crystallizing the resulting salt from the solution.
[0031] The present invention also provides a process for the preparation of compound I which process comprises dissolving (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid in an appropriate organic solvent or a mixture of solvents and adding (L)-Arginine in crystal form, as a suspension or dissolved in an appropriate solvent or mixture of solvents and crystallizing the resulting salt from the solution, or by other processes by which compound I can be prepared. Preferably (L)-Arginine is dissolved in water before added to (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid.
[0032] Examples of organic solvents include but are not limited to alcohol's as e.g. methanol, ethanol, 1-propanol, 2-propanol, butanol's or other organic solvents as e.g. acetonitrile, dioxane, tetrahydrofurane, ethers as e.g. t-butylmethylether, N,N-dimethylformamide, N-methyl-2-pyrrolidinone, sulfolane, dimethylsulfoxide, 1,3-dimethyl-3,4,5,6-tetrahydroxy-2(1H)-pyrimidinone.
[0033] Furthermore, the present compounds of formula I can be utilised in the treatment and/or prevention of conditions mediated by nuclear receptors, in particular the Peroxisome Proliferator-Activated Receptors (PPAR).
[0034] In a further aspect, the present invention relates to a method of treating and/or preventing Type I or Type II diabetes.
[0035] In a still further aspect, the present invention relates to the use of one or more compounds of the invention for the preparation of a medicament for the treatment and/or prevention of Type I or Type II diabetes.
[0036] In a still further aspect, the present compounds are useful for the treatment and/or prevention of IGT.
[0037] In a still further aspect, the present compounds are useful for the treatment and/or prevention of Type 2 diabetes.
[0038] In a still further aspect, the present compounds are useful for the delaying or prevention of the progression from IGT to Type 2 diabetes.
[0039] In a still further aspect, the present compounds are useful for the delaying or prevention of the progression from non-insulin requiring Type 2 diabetes to insulin requiring Type 2 diabetes.
[0040] In another aspect, the present compounds reduce blood glucose and triglyceride levels and are accordingly useful for the treatment and/or prevention of ailments and disorders such as diabetes and/or obesity.
[0041] In still another aspect, the present compounds are useful for the treatment and/or prophylaxis of insulin resistance (Type 2 diabetes), impaired glucose tolerance, dyslipidemia, disorders related to Syndrome X such as hypertension, obesity, insulin resistance, hyperglycaemia, atherosclerosis, hyperlipidemia, coronary artery disease, myocardial ischemia and other cardiovascular disorders.
[0042] In still another aspect, the present compounds are effective in decreasing apoptosis in mammalian cells such as beta cells of Islets of Langerhans.
[0043] In still another aspect, the present compounds are useful for the treatment of certain renal diseases including glomerulonephritis, glomerulosclerosis, nephrotic syndrome, hypertensive nephrosclerosis.
[0044] In still another aspect, the present compounds may also be useful for improving cognitive functions in dementia, treating diabetic complications, psoriasis, polycystic ovarian syndrome (PCOS) and prevention and treatment of bone loss, e.g. osteoporosis.
[0045] Furthermore, the invention relates to the use of the present compounds and pharmaceutically acceptable salts thereof for the preparation of a pharmaceutical composition for the treatment and/or prevention of conditions mediated by nuclear receptors, in particular the Peroxisome Proliferator-Activated Receptors (PPAR) such as the conditions mentioned above.
[0046] The present invention also provides pharmaceutical compositions comprising a crystalline compound of the present invention optionally in combination with a pharmaceutically acceptable carrier or diluent.
[0047] Pharmaceutical compositions containing a crystalline compound of the present invention and optionally other compounds as mentioned underneath may be prepared by conventional techniques, e.g. as described in Remington: The Science and Practise of Pharmacy, 19 th Ed., 1995. The compositions may appear in conventional forms, for example capsules, tablets, aerosols, solutions, suspensions or topical applications.
[0048] The present compounds may also be administered in combination with one or more further pharmacologically active substances eg. selected from antiobesity agents, antidiabetics, antihypertensive agents, agents for the treatment and/or prevention of complications resulting from or associated with diabetes and agents for the treatment and/or prevention of complications and disorders resulting from or associated with obesity.
[0049] Thus, in a further aspect of the invention the present compounds may be administered in combination with one or more antiobesity agents or appetite regulating agents.
[0050] Such agents may be selected from the group consisting of CART (cocaine amphetamine regulated transcript) agonists, NPY (neuropeptide Y) antagonists, MC4 (melanocortin 4) agonists, orexin antagonists, TNF (tumor necrosis factor) agonists, CRF (corticotropin releasing factor) agonists, CRF BP (corticotropin releasing factor binding protein) antagonists, urocortin agonists, β3 agonists, MSH (melanocyte-stimulating hormone) agonists, MCH (melanocyte-concentrating hormone) antagonists, CCK (cholecystokinin) agonists, serotonin re-uptake inhibitors, serotonin and noradrenaline re-uptake inhibitors, mixed serotonin and noradrenergic compounds, 5HT (serotonin) agonists, bombesin agonists, galanin antagonists, growth hormone, growth hormone releasing compounds, TRH (thyreotropin releasing hormone) agonists, UCP 2 or 3 (uncoupling protein 2 or 3) modulators, leptin agonists, DA agonists (bromocriptin, doprexin), lipase/amylase inhibitors, RXR (retinoid X receptor) modulators or TR β agonists.
[0051] In one embodiment of the invention the antiobesity agent is leptin.
[0052] In another embodiment the antiobesity agent is dexamphetamine or amphetamine.
[0053] In another embodiment the antiobesity agent is fenfluramine or dexfenfluramine.
[0054] In still another embodiment the antiobesity agent is sibutramine.
[0055] In a further embodiment the antiobesity agent is orlistat.
[0056] In another embodiment the antiobesity agent is mazindol or phentermine.
[0057] Suitable antidiabetics comprise insulin, GLP-1 (glucagon like peptide-1) derivatives such as those disclosed in WO 98/08871 to Novo Nordisk A/S, which is incorporated herein by reference as well as orally active hypoglycaemic agents.
[0058] The orally active hypoglycaemic agents preferably comprise sulphonylureas, biguanides, meglitinides, glucosidase inhibitors, glucagon antagonists such as those disclosed in WO 99/01423 to Novo Nordisk A/S and Agouron Pharmaceuticals, Inc., GLP-1 agonists, potassium channel openers such as those disclosed in WO 97/26265 and WO 99/03861 to Novo Nordisk A/S which are incorporated herein by reference, DPP-IV (dipeptidyl peptidase-IV) inhibitors, inhibitors of hepatic enzymes involved in stimulation of gluconeogenesis and/or glycogenolysis, glucose uptake modulators, compounds modifying the lipid metabolism such as antihyperlipidemic agents and antilipidemic agents as HMG CoA inhibitors (statins), compounds lowering food intake, RXR agonists and agents acting on the ATP-dependent potassium channel of the β-cells.
[0059] In one embodiment of the invention the present compounds are administered in combination with insulin.
[0060] In a further embodiment the present compounds are administered in combination with a sulphonylurea eg. tolbutamide, glibenclamide, glipizide or glicazide.
[0061] In another embodiment the present compounds are administered in combination with a biguanide eg. mefformin.
[0062] In yet another embodiment the present compounds are administered in combination with a meglitinide eg. repaglinide.
[0063] In a further embodiment the present compounds are administered in combination with an α-glucosidase inhibitor eg. miglitol or acarbose.
[0064] In another embodiment the present compounds are administered in combination with an agent acting on the ATP-dependent potassium channel of the β-cells eg. tolbutamide, glibenclamide, glipizide, glicazide or repaglinide.
[0065] Furthermore, the present compounds may be administered in combination with nateglinide.
[0066] In still another embodiment the present compounds are administered in combination with an antihyperlipidemic agent or antilipidemic agent eg. cholestyramine, colestipol, clofibrate, gemfibrozil, lovastatin, pravastatin, simvastatin, probucol or dextrothyroxine.
[0067] In a further embodiment the present compounds are administered in combination with more than one of the above-mentioned compounds eg. in combination with a sulphonylurea and mefformin, a sulphonylurea and acarbose, repaglinide and mefformin, insulin and a sulphonylurea, insulin and mefformin, insulin, insulin and lovastatin, etc.
[0068] Furthermore, the present compounds may be administered in combination with one or more antihypertensive agents. Examples of antihypertensive agents are β-blockers such as alprenolol, atenolol, timolol, pindolol, propranolol and metoprolol, ACE (angiotensin converting enzyme) inhibitors such as benazepril, captopril, enalapril, fosinopril, lisinopril, quinapril and ramipril, calcium channel blockers such as nifedipine, felodipine, nicardipine, isradipine, nimodipine, diltiazem and verapamil, and α-blockers such as doxazosin, urapidil, prazosin and terazosin. Further reference can be made to Remington: The Science and Practice of Pharmacy, 19 th Edition, Gennaro, Ed., Mack Publishing Co., Easton, Pa., 1995.
[0069] It should be understood that any suitable combination of the compounds according to the invention with one or more of the above-mentioned compounds and optionally one or more further pharmacologically active substances are considered to be within the scope of the present invention.
[0070] Typical compositions include a crystalline compound of the present invention associated with a pharmaceutically acceptable excipient which may be a carrier or a diluent or be diluted by a carrier, or enclosed within a carrier which can be in the form of a capsule, sachet, paper or other container. In making the compositions, conventional techniques for the preparation of pharmaceutical compositions may be used. For example, the active compound will usually be mixed with a carrier, or diluted by a carrier, or enclosed within a carrier which may be in the form of a ampoule, capsule, sachet, paper, or other container. When the carrier serves as a diluent, it may be solid, semi-solid, or liquid material which acts as a vehicle, excipient, or medium for the active compound. The active compound can be adsorbed on a granular solid container for example in a sachet. Some examples of suitable carriers are water, salt solutions, alcohol's, polyethylene glycol's, polyhydroxyethoxylated castor oil, peanut oil, olive oil, gelatine, lactose, terra alba, sucrose, cyclodextrin, amylose, magnesium stearate, talc, gelatine, agar, pectin, acacia, stearic acid or lower alkyl ethers of cellulose, silicic acid, fatty acids, fatty acid amines, fatty acid monoglycerides and diglycerides, pentaerythritol fatty acid esters, polyoxyethylene, hydroxymethylcellulose and polyvinylpyrrolidone. Similarly, the carrier or diluent may include any sustained release material known in the art, such as glyceryl monostearate or glyceryl distearate, alone or mixed with a wax. The formulations may also include wetting agents, emulsifying and suspending agents, preserving agents, sweetening agents or flavouring agents. The formulations of the invention may be formulated so as to provide quick, sustained, or delayed release of the active ingredient after administration to the patient by employing procedures well known in the art.
[0071] The pharmaceutical compositions can be sterilized and mixed, if desired, with auxiliary agents, emulsifiers, salt for influencing osmotic pressure, buffers and/or colouring substances and the like, which do not deleteriously react with the active compound.
[0072] The route of administration may be any route, which effectively transports the active compound to the appropriate or desired site of action, such as oral, nasal, pulmonary, transdermal or parenteral e.g. rectal, depot, subcutaneous, intravenous, intraurethral, intramuscular, intranasal, ophthalmic solution or an ointment, the oral route being preferred.
[0073] If a solid carrier is used for oral administration, the preparation may be tablefted, placed in a hard gelatine capsule in powder or pellet form or it can be in the form of a troche or lozenge. If a liquid carrier is used, the preparation may be in the form of a syrup, emulsion, soft gelatine capsule or sterile injectable liquid such as an aqueous or non-aqueous liquid suspension or solution.
[0074] For nasal administration, the preparation may contain the compound of the present invention dissolved or suspended in a liquid carrier, in particular an aqueous carrier, for aerosol application. The carrier may contain additives such as solubilizing agents, e.g. propylene glycol, surfactants, absorption enhancers such as lecithin (phosphatidylcholine) or cyclodextrin, or preservatives such as parabenes.
[0075] For parenteral application, particularly suitable are injectable solutions or suspensions, preferably aqueous solutions with the active compound dissolved in polyhydroxylated castor oil.
[0076] Tablets, dragees, or capsules having talc and/or a carbohydrate carrier or binder or the like are particularly suitable for oral application. Preferable carriers for tablets, dragees, or capsules include lactose, corn starch, and/or potato starch. A syrup or elixir can be used in cases where a sweetened vehicle can be employed.
[0077] A typical tablet which may be prepared by conventional tabletting techniques may contain:
Core: Active compound 5 mg Colloidal silicon dioxide (Aerosil) 1.5 mg Cellulose, microcryst. (Avicel) 70 mg Modified cellulose gum (Ac-Di-Sol) 7.5 mg Magnesium stearate Ad. Coating: HPMC approx. 9 mg *Mywacett 9-40 T approx. 0.9 mg *Acylated monoglyceride used as plasticizer for film coating.
[0078] The compounds of the invention may be administered to a mammal, especially a human in need of such treatment, prevention, elimination, alleviation or amelioration of diseases related to the regulation of blood sugar.
[0079] Such mammals include also animals, both domestic animals, e.g. household pets, and nondomestic animals such as wildlife.
[0080] The compounds of the invention are effective over a wide dosage range. For example, in the treatment of adult humans, dosages from about 0.05 to about 100 mg, preferably from about 0.1 to about 100 mg, per day may be used. A most preferable dosage is about 0.1 mg to about 70 mg per day. In choosing a regimen for patients it may frequently be necessary to begin with a dosage of from about 2 to about 70 mg per day and when the condition is under control to reduce the dosage as low as from about 0.1 to about 10 mg per day. The exact dosage will depend upon the mode of administration, on the therapy desired, form in which administered, the subject to be treated and the body weight of the subject to be treated, and the preference and experience of the physician or veterinarian in charge.
[0081] Generally, the compounds of the present invention are dispensed in unit dosage form comprising from about 0.1 to about 100 mg of active ingredient together with a pharmaceutically acceptable carrier per unit dosage.
[0082] Usually, dosage forms suitable for oral, nasal, pulmonary or transdermal administration comprise from about 0.001 mg to about 100 mg, preferably from about 0.01 mg to about 50 mg of the compound of the invention admixed with a pharmaceutically acceptable carrier or diluent.
[0000] Pharmacological Methods
[0000] In vitro PPAR Alpha and PPAR Gamma Activation Activity.
[0000] Principle
[0083] The PPAR gene transcription activation assays were based on transient transfection into human HEK293 cells of two plasmids encoding a chimeric test protein and a reporter protein respectively. The chimeric test protein was a fusion of the DNA binding domain (DBD) from the yeast GAL4 transcription factor to the ligand binding domain (LBD) of the human PPAR proteins. The PPAR LBD harbored in addition to the ligand binding pocket also the native activation domain (activating function 2=AF2) allowing the fusion protein to function as a PPAR ligand dependent transcription factor. The GAL4 DBD will force the fusion protein to bind only to Gal4 enhancers (of which none existed in HEK293 cells). The reporter plasmid contained a Gal4 enhancer driving the expression of the firefly luciferase protein. After transfection, HEK293 cells expressed the GAL4-DBD-PPAR-LBD fusion protein. The fusion protein will in turn bind to the Gal4 enhancer controlling the luciferase expression, and do nothing the absence of ligand. Upon addition to the cells of a PPAR ligand, luciferase protein will be produced in amounts corresponding to the activation of the PPAR protein. The amount of luciferase protein is measured by light emission after addition of the appropriate substrate.
[0000] Methods
[0084] Cell culture and transfection: HEK293 cells were grown in DMEM+10% FCS, 1% PS. Cells were seeded in 96-well plates the day before transfection to give a confluency of 80% at transfection. 0.8 μg DNA per well was transfected using FuGene transfection reagent according to the manufacturers instructions (Boehringer-Mannheim). Cells were allowed to express protein for 48 h followed by addition of compound.
[0085] Plasmids: Human PPAR α and γ was obtained by PCR amplification using cDNA templates from liver, intestine and adipose tissue respectively. Amplified cDNAs were cloned into pCR2.1 and sequenced. The LBD from each isoform PPAR was generated by PCR (PPARα: aa 167-C-term; PPARγ: aa 165-C-term) and fused to GAL4-DBD by subcloning fragments in frame into the vector pM1 generating the plasmids pM1αLBD and pM1γLBD. Ensuing fusions were verified by sequencing. The reporter was constructed by inserting an oligonucleotide encoding five repeats of the Gal4 recognition sequence into the pGL2 vector (Promega).
[0086] Compounds: All compounds were dissolved in DMSO and diluted 1:1000 upon addition to the cells. Cells were treated with compound (1:1000 in 200 μl growth medium including delipidated serum) for 24 h followed by luciferase assay.
[0087] Luciferase assay: Medium including test compound was aspirated and 100 μl PBS incl. 1 mM Mg++ and Ca++ was added to each well. The luciferase assay was performed using the LucLite kit according to the manufacturers instructions (Packard Instruments). Light emission was quantified by counting SPC mode on a Packard Instruments top-counter.
[0088] The present invention is further illustrated by the following examples which, however, are not to be construed as limiting the scope of protection. The features disclosed in the foregoing description and in the following examples may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.
[0089] Crystalline (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate was synthesized, purified and crystallized as described in the following example. Any novel feature or combination of features described herein is considered essential to this invention.
EXAMPLES
Synthesis of (2S)-2-Ethoxy-3-(4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid
[0000] Materials
[0090] All solvents and reagents were purchased from Aldrich and Merck and used without further purification.
Ethyl-2-(10H-phenoxazin-10-yl)acetate
[0091]
[0092] A solution of phenoxazine (10 g, 54.6 mmol) in dry dimethyl formamide (15 ml) was added slowly to a stirred ice cooled suspension of sodium hydride (60% dispersion in oil) (2.88 g, 60.1 mmol) in dimethyl formamide (10 ml), under an atmosphere of nitrogen. The mixture was stirred at 80° C. for 2 h and cooled to 0° C. and ethyl bromoacetate (12.78 g, 76.50 mmol) was added dropwise and stirring was continued for 12 h at 25° C. (TLC monitored). Water (50 ml) was added and the aqueous phase extracted with ethyl acetate (2×75 ml). The combined organic phases were washed with water (50 ml), brine (5 ml), dried (Na 2 SO 4 ), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel (100-200 mesh) using a mixture of benzene and petroleum ether (1:1) to afford the title compound (5.7 g, 39%) as a pale bluish green solid. mp: 96-97° C.
[0093] Note: DMF should be perfectly dry.
[0000] TLC Conditions:
[0094] TLC (visualised in UV and 12) Eluent:Benzene:Petroleum ether (1:1), R f =0.6.
2-(10H-Phenoxazin-10-yl)-1-ethanol
[0095]
[0096] A solution of ethyl-2-(10H-phenoxazin-10-yl)acetate (5.5 g, 20.44 mmol) in dry tetrahydrofuran (20 ml) was added dropwise to a suspension of lithium aluminum hydride (1.16 g, 30.52 mmol) in dry tetrahydrofurane (20 ml) at 0° C. The reaction mixture was warmed to room temperature and stirred for additional 1 h. The excess lithium aluminum hydride was quenched with a solution of saturated sodium sulfate at 0° C. The reaction mixture was filtered and the residue was washed with hot ethyl acetate (2×75 ml). The combined organic layers were dried (Na 2 SO 4 ), filtered and the solvent was evaporated under reduced pressure to afford the title compound (4.6 g, 99%) as a colourless solid. The compound is used in the next step without further purification. mp: 113-115° C.
[0000] TLC Conditions:
[0097] TLC (visualised in UV and I 2 ); Eluent, EtOAc:Petroleum ether (3:7), R f =0.3.
2-(10H-Phenoxazin-10-yl)ethyl methanesulfonate
[0098]
[0099] To a solution of 2-(10H-phenoxazin-10-yl)-1-ethanol (4.6 g, 20.28 mmol) in dichloromethane (20 ml) was added triethylamine (1.06 9, 10.56 mmol) under an atmosphere of nitrogen at 25° C. Methanesulfonyl chloride (0.90 g, 7.92 mmol) was added to the above reaction mixture at 0° C. and stirring was continued for further 3 h at 25° C. Water (50 ml) was added, and aqueous phase extracted with chloroform (2×25 ml). The combined organic phases were washed with water (25 ml), dried (Na 2 SO 4 ), filtered and the solvent was evaporated under reduced pressure. The residue was triturated with petroleum ether to afford the title compound (5.7 g, 92%) as a solid. mp: 81-83° C.
[0000] TLC Conditions:
[0100] TLC (visualised in UV and 12); Eluent:MEOH:CHCl 3 (1:99), R f =0.6.
Ethyl-(E/Z)-3-[4-(benzyloxy)phenyl]-2-ethoxy-propenoate
[0101]
[0102] A solution of triethyl-2-ethoxyphosphonoacetate (9) prepared by the method of Grell and Machleidt, Annalen. Chemie, 1996, 699, 53 (3.53 g, 13.2 mmol) in dry tetrahydrofurane (10 ml) was added slowly to a stirred ice cooled suspension of sodium hydride (60% dispersion of oil) (0.62 g, 12.97 mmol) in dry tetrahydrofuran (5 ml), under an atmosphere of nitrogen. The mixture was stirred at 0° C. for 30 min followed by the addition of 4-benzyloxybenzaldehyde (2.5 g, 11.79 mmol) dissolved in dry tetrahydrofurane (20 ml). The mixture was allowed to warm to room temperature and stirred for additional 20 h. The excess sodium hydride was quenched with a few drops of cold water. The solvent was evaporated, water (100 ml) was added and the aqueous phase extracted with ethyl acetate (2×75 ml). The combined organic extracts were washed with water (50 ml), brine (50 ml), dried (Na 2 SO 4 ), filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and petroleum ether (2:8) as the eluent to afford the title compound (3.84 g, quantitative) as an oil. 1 H NMR of the product suggests a (76:24=Z:E) mixture of geometric isomers (R. A. Aitken and G. L. Thom, Synthesis, 1989, 958).
[0000] TLC Conditions:
[0103] TLC (visualised in UV and I 2 ); Eluent, EtOAc:petroleum ether (1:9), 2 spots (E/Z isomers), R f =0.48 and 0.46.
[0104] Note: This compound can be obtained as a pale yellow solid, mp: 50-52° C.
Ethyl-(2R/2S)-2-ethoxy-3-(4-hydroxyphenyl)propanoate
[0105]
[0106] A suspension of ethyl Ethyl-(E/Z)-3-[4-(benzyloxy)phenyl]-2-ethoxy-propenoate (3.85 g, 11.80 mmol) and 10% Pd-C (0.30 g) in ethyl acetate (50 ml) was stirred at 25° C. under 60 psi of hydrogen pressure for 24 h. The catalyst was filtered off and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel using a mixture of ethyl acetate and petroleum ether (2:8) to afford the title compound (1.73 g, 61%) as an oil.
[0000] TLC Conditions:
[0107] TLC (visualised in UV and I 2 ) Eluent, EtOAc:petroleum ether (1:5), R f =0.35.
Ethyl-(2R/2S)-2-ethoxy 3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate
[0108]
[0109] A mixture of 2-(10H-Phenoxazin-10-yl)ethyl methanesulfonate (0.5 g, 1.63 mmol), Ethyl-(2R/2S)-2-ethoxy-3-(4-hydroxyphenyl)propanoate (0.46 g, 1.9 mmol) and potassium carbonate (0.45 g, 3.2 mmol) in dry dimethyl formamide (20 ml) was stirred for 12 h at 80° C. The reaction mixture was cooled to room temperature. Water (40 ml) was added and the aqueous phase was extracted with ethyl acetate (2×50 ml). The combined organic phases were washed with water (50 ml), dried (Na 2 SO 4 ) filtered and the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel (100-200 mesh) using a mixture of ethyl acetate and petroleum ether (1:9) to afford the title compound (0.55 g. 75%) as a white solid. mp: 51-53° C.
[0110] TLC (visualised in 12); Eluent, EtOAc:petroleum ether (1:9), R f =0.7.
(2R/2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl]ethoxy]phenyl}propanoic acid
[0111]
[0112] To a solution of Ethyl-(2R/2S)-2-ethoxy 3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}-propanoate (62 g, 138.7 mmol) in methanol (1000 ml) was added 10% aqueous sodium hydroxide solution (300 ml). The mixture was stirred at 25° C. for 6 h. Methanol was evaporated under reduced pressure, water (200 ml) was added and acidified with 2N hydrochloric acid. The mixture was extracted with ethyl acetate (3×500 ml). The combined organic phases were washed with water (2×500 ml), brine (500 ml), dried (Na 2 SO 4 ), filtered and the solvent evaporated under reduced pressure. The residue was triturated with petroleum ether to afford the title compound (56 g, 96%) as a white solid. mp: 89-91° C.
[0000] TLC Conditions:
[0113] TLC (visualised in I 2 ); Eluent. EtOAc:petroleum ether (3:1)e, R f =0.4.
[0000] HPLC Conditions:
[0114] Lichrosphere RP C 18 -0.01 m KH 2 PO 4 :Acetonitrile, 25:75, (pH=3.0). Flow: 1 ml/min.
[0115] λmax: 245 nm.
[0116] Resolution of the (R/S) (±) form on chiral column.
[0117] Chiralcel—OJ, Hexane:EtOH:AcOH (90:10:0.3). Flow: 1.2 ml/min.
[0118] λmax=245 nm.
[0119] (+) form: R t : 42. 40 min. (−) form: R t =36.10 min.
(2S)-2-ethoxy-N-[(1S)-2-hydroxy-1-phenylethyl]-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanamide
[0120]
[0121] To an ice cooled solution (2R/2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl]ethoxy]phenyl}propanoic acid (1.2 g, 2.9 mmol) and triethylamine (0.58 g. 5.8 mmol) in dry dichloromethane (25 ml) was added pivaloyl chloride (0.38 g, 3.19 mmol) and stirring was continued for 30 min at 0° C. A mixture of (S)-2-phenylglycinol (0.39 g, 2.9 mmol) and triethylamine (0.58 g, 5.8 mmol) in dichloromethane (20 ml) was added to the above reaction mixture at 0° C. and stirring was continued for 2 h at 25° C. Water (50 ml) was added and the aqueous phase extracted with dichloromethane (2×50 ml). The combined organic phases were washed with water (2×25 ml), brine (25 ml), dried (Na 2 SO 4 ) and evaporated. The residue was chromatographed over silica gel using a gradient of 40-60% ethyl acetate in petroleum ether as an eluent to afford the two diastereomers: (2S)-2-ethoxy-N-[(1S)-2-hydroxy-1-phenylethyl]-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanamide (0.55 g, 35%) and (2S)-2-ethoxy-N-[(1R)-2-hydroxy-1-phenylethyl]-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanamide (0.5 g, 32%).
(2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid
[0122]
[0123] (2S)-2-Ethoxy-N-[(1S)-2-hydroxy-1-phenylethyl]-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanamide (0.45 g, 0.84 mmol) was dissolved in a mixture of 1M sulphuric acid (17 ml) and dioxane/water (1:1.39 ml) and heated to 90° C. for 88 h. The pH of the mixture was adjusted to 3 by addition of an aqueous sodium hydrogen carbonate solution. The mixture was extracted with ethyl acetate (2×25 ml) and the organic phase was washed with water (50 ml), brine (25 ml), dried (Na 2 SO 4 ) and evaporated. The residue was chromatographed over silica gel using a gradient of 50-75% ethyl acetate in petroleum ether to afford the title compound (0.19 g, 54%) as a white solid. mp: 89-90° C.
Syntheses of (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(I OH-phenoxazin-10-yl)ethoxy]phenyl}-propanoate
[0124]
[0125] (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid (104.3 g; 249 mmol) was dissolved in ethanol (2.0 I), filtered (filter-paper) and transferred to a 4 I reactor. The used glass equipment was washed with ethanol (0.6 I) to get a quantitative transfer of the compound.
[0126] (L)-Arginine (43.38 g; 249 mmol) was dissolved in water (150 ml) at 50-60° C. and added to the solution of (2S)-2-ethoxy-3-{4-[2-( 1H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid heated to 75-80° C. (The solution was homogeneous after the addition).
[0127] The mixture was cooled slowly to room temperature over night to get a precipitation (seeding can be an advantage in some cases). The following day the suspension was cooled to 0-5° C. and filtered. The product was washed with ethanol (100 ml×2) and dried in vacuum until no further weight loss could be detected. The process yielded 135 g; 91% of the title product.
Syntheses of (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}-propanoate
[0128] (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid (300 mg; 0.72 mmol) was dissolved in isopropanol (3 ml), filtered and transferred to a flask.
[0129] (L)-Arginine (124.6 mg, 0.72 mmol) was dissolved in water (½ ml) at 50-60° C. and added to the solution of (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoic acid, heated to reflux.
[0130] The mixture was kept for 10 days at 40° C., cooled to room temperature and filtered. The product was dried in vacuum. The process yielded 300 mg of the title product, M.p. 181° C.
Analytical data for (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate
[0131] The crystals were characterised by the following methods: 1 H-NMR spectra and elemental analysis.
[0000] 1 H-NMR of Compound I
[0132] used solvent: mixture of [ 2 H 6 ]DMSO (δ=2.49) and D 2 O (δ=3.5)
Chemical Shift Coupling Coupling Constants 1 H δ (ppm) Integral Pattern n J HH (Hz) H1, H2, H3, H4, 6.6-6.9 8H m ND (=not H5, H6, H7, H8 determined) H9, H9′ 4.15 2H t 3 J HH = 6 H10, H10′ 3.97 2H t 3 J HH = 6 H11, H14 6.77 2H A-part of 3 J HH = 8 AB- pattern H12, H13 7.10 2H B-part of 3 J HH = 8 AB- pattern H14 2.82 1H dd 2 J HH = 14, 3 J HH = 4 H14′ 2.63 1H dd 2 J HH = 14, 3 J HH = 9 H15 3.58 1H dd 3 J HH = 4, 3 J HH = 9 H16 3.52 1H dq 2 J HH = 9.5, 3 J HH = 7 H16′ 3.13 1H dq 2 J HH = 9.5, 3 J HH = 7 H17 0.97 3H t 3 J HH = 7 H18 3.23 1H t 3 J HH = 5 H19 1.65 1H m ND H19′ 1.75 1H m ND H20 1.57 2H m ND H21 3.05 1H m ND
Elemental Analysis
[0133] The elemental composition of compound I was determined as follows: Calculated composition data: C, 62.68%; H, 6.65%; N, 11.70% Found: C, 62.72%; H, 6.62%; N, 11.80%. | The present invention relates to crystalline R-guanidines of (2S)-2-Ethoxy-3{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparations and its use as therapeutic agents. More specifically the present invention relates to crystalline Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, preferably (L)-Arginine (2S)-2-Ethoxy-3-{4-[2-(10H-phenoxazin-10-yl)ethoxy]phenyl}propanoate, its preparation and its use as therapeutic agent. | 0 |
[0001] The present invention relates to a direct reading endoscopic measuring instrument and, more specifically, to a manually operated measuring instrument that is placed in close proximity to an internal anatomical feature and a related method for operation of the measuring instrument.
[0002] BACKGROUND
[0003] With advances in optics and miniaturized assembly techniques, endoscopes now play a vital role in modern medicine. Endoscopes are flexible surgical tools used to introduce mechanical instruments, fluids, viewing instruments, and the like into a body. An endoscope, which generally has a tubular shape, is fed into an opening or incision in a body until the distal end of the endoscope is proximate a site to be observed or operated on. The interior of the endoscope includes one or more bores or lumens. These lumens act as passages for various instruments or tools that facilitate diagnostic or therapeutic procedures. For instance, a fiber optic cable with an optical lens (camera) can be integral to the endoscope or extended the length of the endoscope. The camera is operable to view the tissue proximate to the digital end of the endoscope. Other lumens can be used to provide light, fluids, mechanical surgical tools, or the like. Endoscopes are extremely useful to observe or biopsy internal organs such as the colon, bladder, stomach, lungs, liver, or the like. Overall, endoscopes have revolutionalized many procedures by giving the operating doctor much greater information from, and access to, internal structures without an invasive procedure. Doctors can now observe and diagnose organs and joints with minimal impact.
[0004] One area where endoscopes are used routinely is in the observation and measurement of tumors, internal growths, or other anatomical structures (ulcers, tears, scars, etc.). The size of such structures can be measured in a variety of ways. For instance, it is known to place graduations onto the camera lens of a fiber optic camera placed within an endoscope. Although the graduation measurements on the lens may be known, it is only possible to estimate the size of the internal structure because the distance from the lens to the structure is unknown. This type of measurement technique does not provide the depth of the structure. Another common solution is to electronically calculate the size of a structure. To accomplish this, a tool with uneven graduations will be placed near a structure. The observation equipment calculates a size scale to correct for the uneven graduations. This approach is generally expensive, overly complex, and not entirely accurate. Typically, this calculated method, as opposed to a direct reading method, will only measure the structure in one direction.
[0005] Measurement tools are known to have unevenly spaced graduations that are formed at a tip end portion of a flexible shaft. The shaft is detachably inserted through an instrument tool channel in an endoscope. The shaft is placed next to the structure, and can be observed via a camera. Again, the size of an internal structure can only be measured in one direction. The orientation of the shaft prohibits measurements in two directions. So while it is thought to be an improvement to have a direct reading tool, it is also thought to be nearly impossible to directly measure the dimensions of an object in two different directions with such a tool. Moreover, the known tools may require more than one measuring instrument, endoscope, or are otherwise overly complex. Direct reading tools may not take measurements along an axis perpendicular to the endoscope.
[0006] As such, there is a clear need within the medical industry for an inexpensive, easy to operate, simple, durable, and selectively removable direct reading endoscopic measurement instrument (‘DREMI’). Ideally, the DREMI provides accurate measurements of internal structures in at least one direction, including along an axis perpendicular to the endoscope. The apparatus and method of the present invention would effectively address shortcomings as known in the prior art.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, a DREMI, and method for operating the DREMI, are provided that include a manually operated measuring instrument that is placed in close proximity to an internal anatomical feature. The DREMI is inserted into a body, such as a human body, through an endoscope. When the DREMI is properly positioned, a reticule is unfolded proximate to an anatomical structure. Using evenly spaced graduations on the reticule, an operator can directly measure the structure via an endoscopic camera, as known in the art, that is included in the endoscope.
[0008] The distal reticule provided by the DREMI is extended past the distal (inserted) end of the endoscope in a folded condition. A manual actuator, as known in the art, is operable to unfold the distal reticule proximate to the anatomical feature once the reticule has exited the endoscope. In the unfolded state, the distal reticule is substantially perpendicular to the axis of the endoscope. The graduations on the DREMI allow an attendant, physician or other operator to directly measure the size of the anatomical feature in question in at least one direction, including along an axis perpendicular to the endoscope.
[0009] The DREMI includes the manual actuator, a coil pipe with an actuator wire, and the distal reticule wherein the actuator wire connects the actuator to the unfoldable distal reticule. The coil pipe and folded distal reticule are inserted into a channel provided by an endoscope, either before or after the endoscope is positioned with the body. The actuator is external to both the body and endoscope for actuation by an operator. The size and length of the DREMI will be determined, in part, by the size and length of the endoscope being used for the particular medical procedure that is to be performed. The reticule is naturally biased into the folded position.
[0010] In a preferred embodiment, the actuator is a commonly used slide trigger that is secured to both the proximal end of the coil pipe and to an actuator wire for selectively unfolding the distal reticule. Sliding the trigger towards the coil pipe along the length of the actuator operates to retract the actuator wire at the distal reticule. Retracting the actuator wire causes the reticule to unfold when the reticule has been passed out of the distal end of the endoscope. Other types of actuators are available, and the structure of the actuator and direction of activation are not important to the present invention.
[0011] In one preferred embodiment, the reticule includes evenly spaced graduations along at least a portion of the length of the reticule. The graduations are visible in both the unfolded and folded states via an endoscopic camera. In this manner, the DREMI can be used to measure an anatomical structure in at least one direction, including along an axis perpendicular to the endoscope. The image from the endoscopic camera does not need to be scaled.
[0012] A DREMI and the related method of operation in accordance with the present invention efficiently address at least one of the shortcomings associated with prior art endoscopic measuring devices. The foregoing and additional features and advantages of the present invention will become apparent to those of skill in the art from the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of a DREMI in accordance with one embodiment of the present invention;
[0014] FIG. 2 is a close-up view of a DREMI in accordance with the present invention wherein the DREMI is extending out of the distal end of an endoscope;
[0015] FIG. 3 is a close-up view of the distal end of a DREMI in accordance with the present invention;
[0016] FIG. 4 is another close-up view of the distal end of a DREMI in accordance with the present invention;
[0017] FIG. 5 is a side view of the reticule provided by the DREMI wherein the reticule is spread apart along the length of the reticule; and
[0018] FIG. 6 is a bottom view thereof.
DETAILED DESCRIPTION
[0019] A DREMI in accordance with the present invention provides the medical industry with an inexpensive, easy to operate, simple, durable, and selectively removable direct reading endoscopic measurement instrument. The DREMI provides accurate measurements of internal structures in at lease one direction, including along an axis perpendicular to the endoscope.
[0020] Turning to FIG. 1 , the DREMI 10 is illustrated as including an actuator 12 , a coil pipe 14 with an actuator wire 16 , and a distal reticule 18 . Actuator 12 is connected to the distal reticule by the coil pipe and actuator wire. The coil pipe and actuator wire are illustrated here in broken lines to convey the length of the DREMI. DREMI 10 will be fed through an endoscope in order to reach an internal anatomical structure. The length of the coil pipe and actuator wire must be sufficient to extend the distal reticule past the distal end of the endoscope. Coil pipe 14 might be encased by a larger outer coil pipe 20 near the actuator for increased durability. Outer coil pipe 20 would terminate at a relatively short distance in comparison to the length of coil pipe 14 .
[0021] In a preferred embodiment, actuator 12 is a commonly used actuator. For instance, the illustrated actuator is available from Olympus™, and it can be used with a number of endoscopic tools. Actuator wire 16 is thread through coil pipe 14 and connects a slide 22 on actuator 12 with a distal tool, in this case distal reticule 18 . The actuator body is an injection molded plastic secured, by known means, to coil pipe 14 and optional outer coil pipe 20 . The actuator wire passes from slide 22 to the inside of coil pipes 14 , 20 via an aperture sized and dimensioned to accept wire 16 . The connection of wire 16 to slide 22 is not important for the present invention and is known in the art.
[0022] The end of actuator 12 opposite coil pipe 14 provides a thumb grip 24 . In use, a user places their thumb in grip 24 with slide 22 between their index and middle fingers. Slide 22 can then be forcibly positioned along a shaft 26 . Pushing slide 22 away from grip 24 (i.e., pushing wire 16 toward reticule 18 ) places a force at the distal end of the wire on distal reticule 18 . Releasing slide 22 allows the slide to return to a natural resting position. Further discussion of the actuator 12 is not warranted here as it is a known device and operation of the actuator will be obvious to one of skill in the art. Various types of actuators are commercially available and would be suitable for use with the DREMI.
[0023] Turning to FIG. 2 , there is illustrated the distal end of an endoscope 30 with bores or lumens. The lumens act as channels for various tools or fluids. The procedure and type of endoscope both used largely determine the functionality of each lumen. For use with DREMI 10 , one lumen might include a camera 32 with a lens connected by an optical fiber to a video unit (not illustrated) that displays an anatomical structure to the endoscope/DREMI operator. A secondary optical fiber 34 might be connected to a light source (not illustrated) to illuminate the structure for viewing. Lumens 36 and 38 might be fluid channels for water, air, or the like. Endoscopes often supply fluids to a structure in order to clean and dry the structure to be viewed and/or operated on. These are known endoscopic components.
[0024] A tool channel 40 is provided that allows the forward and rearward movement of DREMI 10 within endoscope 30 . A valve structure (not illustrated) or other known endoscopic feature may be included to prevent fluid flow into channel 40 . Of course, it would also be possible to include more or less lumen to perform additional or different tasks than described above. For instance, it is envisioned that more than one channel could be dedicated to providing a tool that extends past the end of the endoscope.
[0025] As illustrated, distal reticule 18 , secured to coil pipe 14 , is extended beyond the distal end of endoscope 30 . Coil pipe 14 is a coiled wire, typically made from stainless steel or a thin-walled plastic tubing. The coil pipe is diminutive enough to be slidable within channel 40 , but it has a sufficient diameter to allow actuator wire 16 to actuate within the coil pipe. Coil pipes and actuator wires are also used in the endoscopic art.
[0026] Returning to FIG. 1 , reticule 18 consists of a molded plastic or other suitable material. As illustrated, reticule 18 is rod-shaped and it terminates at its distal end, relative to the coil pipe, at a semispherical cap 42 to which the distal end of wire 16 is anchored by conventional means. Cap 42 is an integral part of reticule 18 . The proximal end of reticule 18 abuts coil pipe 14 . A cap 43 is crimped onto coil pipe 14 and an anchoring portion of reticule 18 in order to secure the reticule to the coil pipe. Cap 43 can provide an optional graduation mark aligned in the direction of the folded reticule's axis (the graduation mark is illustrated but not labeled). The exact dimensions of reticule 18 are unimportant as the exact size of the DREMI, in general, will be determined by the medical procedure and/or endoscopic equipment in use.
[0027] Reticule 18 has a plurality of distinct body segments wherein each segment can be pivoted relative to any adjacent segment. A pair of upper and lower rulers 44 , 46 form a substantial part of the length of reticule 18 and are parallel to each other in a folded state. The rulers have a semicircular cross section (as better illustrated in FIGS. 5 and 6 ). Rulers 44 , 46 are proximate to the end of coil pipe 14 when reticule 18 is folded. The rulers provide graduations 48 that are placed in 1 mm increments. The graduations can be indentations, inked markings, or the like. They are visible to the DREMI operator via an endoscopic camera when the reticule is in either the folded (parallel to the axis of the endoscope) or unfolded (perpendicular to the axis of the endoscope) states, as will be discussed further below. Rulers 44 , 46 are adjacent the anchored portion of the reticule.
[0028] Additional body segments include the upper backing 50 and lower backing 52 . These parts of the reticule are adjacent to, and integral with, cap 42 (i.e., the distal end of DREMI 10 ). Backings 50 , 52 are roughly the same length as upper and lower rulers 44 , 46 . Further, upper backing 50 is aligned with upper ruler 44 while lower backing 52 is aligned with lower ruler 46 so long as reticule 18 is in the folded state. The upper and lower backings also have semicircular cross sections. When folded, the flat side of each backing contacts the corresponding flat side of the other backing, creating a rod. The rulers are similarly arranged. When folded the backing members and rulers are aligned to create a single rod shape.
[0029] The reticule forms a rod shape that is split down the middle and held together by cap 42 (see FIGS. 5 and 6 ). The rulers and backings bridge the anchored portion of the reticule to cap 42 . The anchored portion of the reticule are physically joined to the rulers. The rulers are physically connected to the backing members, and the backing members are physically connected to cap 42 . The material between each of these sections is scored, cut, molded or otherwise constructed so as to allow the adjacent sections to pivot relative to each other. For instance, the backings pivot relative to the cap, and the anchor portion of reticule 18 (portion of reticule held to coil pipe by crimping cap 43 ) is also pivotally connected to the corresponding rulers.
[0030] Thus, the reticule has three pivot points on each side of its rod shaped body, identified in the figures as elements 54 , 55 , and 56 . Actuating slide 22 away from its naturally biased position pulls cap 42 towards the endoscope. This causes reticule 18 to unfold along the pivot points. In this unfolded state, the body segments of the reticule are aligned substantially perpendicular to the axis of an endoscope. The unfolding action is further illustrated in FIG. 3 , wherein it is illustrated that the middle of the reticule unfolds initially into a diamond shape.
[0031] The fully unfolded reticule is illustrated in FIG. 4 . As will be obvious to one of skill in the art, the upper and lower rulers are aligned along an axis perpendicular to the axis of coil pipe 14 or endoscope 30 . Graduations 48 , placed at evenly spaced intervals along the upper and lower rulers, would be visible to an endoscopic camera. Backings 50 , 52 are behind the rulers. The two backings are now aligned end-to-end. The reticule is held in the unfolded state by pressure on cap 42 in the direction of coil pipe 14 . Releasing slide 22 on actuator 12 releases cap 42 . The reticule returns to a folded state due to a natural biasing force. In the folded state, the reticule can be withdrawn into the endoscope.
[0032] A DREMI or endoscopic operator will, therefore, be able to pass DREMI 10 out of an endoscope so the depth of an anatomical structure could be measured while the DREMI is folded. By actuating actuator 12 , the DREMI unfolds into an alignment perpendicular to the line of sight provided by the endoscopic camera. The operator can directly read the length of the same anatomical structure.
[0033] FIGS. 5 and 6 illustrate reticule 18 in further detail. Without the crimping cap 43 or wire 16 holding reticule 18 together, the two semi-spherical halves of the reticule can be spread apart to form one elongated body. FIGS. 5 and 6 both illustrate the integral relationship of the cap to the backings. The reticule is a single piece of material that is constructed or modified so as to allow for the pivot points 54 , 55 , 56 . In one preferred embodiment, reticule 18 is a molded piece of plastic wherein the material joining all the joints 54 , 55 , 56 is a thin section of malleable plastic. End views for each Figure are identified as elements 60 and 62 , respectively. The series of graduations 48 along the rulers are clearly evenly spaced. The anchor portion that is normally held by crimping cap 43 is labeled in these figures as element 58 .
[0034] FIG. 6 illustrates the bottom side of the spread apart reticule. An axially arranged channel 64 is provided in what is normally the interior of the reticule 18 . Channel 64 nests with wire 16 when reticule 18 is in the folded state. A mounting aperture 66 in cap 42 is sized and shaped to accept wire 16 . The wire can be anchored to the aperture by conventional means, such as an adhesive, welding, or mechanical connection.
[0035] Assembly of the DREMI is accomplished by molding or otherwise constructing the reticule 18 . Crimping cap 42 is placed over the actuator wire and positioned to partially overlap with the coilpipe. A known actuator is attached to the reticule via the actuator wire. A portion of the reticule is overlapped by crimping cap 42 . A crimping force is placed on the crimping cap to hold the reticule to the coil pipe provided by the actuator. In use, an operator simply engages the actuator to fold and unfold the reticule. Other assembly techniques are available and would be obvious to one of skill in the art.
[0036] While the invention has been described with reference to specific embodiments thereof, it will be understood that numerous variations, modifications and additional embodiments are possible, and all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of the invention. | The invention relates to a direct reading endoscopic measuring instrument and, more specifically, to a manually operated measuring instrument that is placed in close proximity to an internal anatomical feature and a related method for operation of the measuring instrument. The direct reading endoscopic measuring instrument includes a distal reticule that is passed through an endoscope in a folded position. When extended past the distal end of the endoscope proximate to an anatomical structure to be measured, a remote actuator unfolds the reticule along an axis perpendicular to the endoscope. Graduations on the reticule can be observed to directly measure the size of the anatomical structure. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a flip-out ironing board with pedestal, sleeveboard, flatiron tray and laundry depository surface.
2. Description of the Related Art
Ironing boards are generally known. However, heretofore no board is known that adequately takes account of the ergonomic aspects.
Thus, ironing boards are on the market into which a few accessories are integrated, such as a flatiron tray, but which, because of their design, permit no other expansions, or these must be mounted additionally.
Consequently, the ironing board becomes either unwieldy, i.e., it can only be transported or stored with difficulty, or these parts must be attached each time prior to use or dismounted on completion of the ironing. This leads to the ergonomic drawbacks mentioned above, which can be overcome by a systematic arrangement of all the accessories to facilitate the work of the operator.
Another problem with known ironing boards is that, if the ironing board is set up on an uneven baseplate, such as a carpet or the like, there are no means for levelling the pedestal.
Also, no ironing boards are known wherein the pedestal is so constructed as to permit ironing in a sitting position.
The arrangement of the pedestal causes the operator's knee to bump against it. Further, in the prior art models it has been shown that the pedestal can flip out inadvertently during transport. This may cause property damage or even injuries.
There is no provision for retaining a squeeze bottle or the like, and thus it may turn over during ironing if no special depository surface is provided therefor.
SUMMARY OF THE INVENTION
Accordingly, the object of the invention is to provide an ironing board into which are integrated as compacted units all the necessary accessories, such as ironing tray, laundry depository surface, etc., that is to say, they are firmly mounted and, if necessary, disposed in such a way that they can be flipped in and out, and wherein all essential ergonomic aspects are given due consideration.
The above object is achieved according to the invention by providing the ironing board with hinges and giving it an ironing surface that can be flipped in and out.
In addition, the flip-out ironing board with pedestal, sleeveboard, flatiron tray and laundry depository surface is characterized by the fact that the pedestal consists of two asymmetrically constructed legs.
According to one embodiment, the flip-out ironing board is characterized by the fact that the legs of the pedestal can be extended in the manner of a telescope, whereby at the terminal end at least at one foot there is disposed a height-adjustable eccentric head knop that can function as a leveling device.
The flip-out ironing board with pedestal, sleeveboard, flatiron tray and laundry depository surface is further characterized by the fact that the laundry depository surface, which is provided with a squeeze bottle tray and a flip-out clothes rack, is placed at the same height as the ironing surface and can be swung thereto or away therefrom.
According to a particularly preferred embodiment, the flip-out ironing board is characterized by the fact that the clothes rack, which is hinged to the laundry depository, is provided with an articulation, which embraces the laundry depository frame and, for the purpose of locating a coat hanger, has a hinged bracket provided with a spring and an abutment cap as well as a lug at its end.
Another preferred embodiment is characterized by the fact that the squeeze bottle tray is disposed within the laundry depository and held at the frame and cross member of the laundry depository for the purpose of locating the squeeze bottle, and has a semicircular recess in the base.
The flip-out ironing board with pedestal, sleeveboard, flatiron tray and laundry depository surface is characterized by the fact that the sleeveboard is mounted such that it can be folded away and retracted.
Further, the flip-out ironing board with pedestal, sleeveboard, flatiron tray and laundry depository surface is characterized by the fact that a safety device provided for transport is disposed below the ironing surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings which show a preferred embodiment, and in which:
FIG. 1 is a front view of the ironing board;
FIG. 2 is a top plan view of the ironing board from direction "A" indicated in FIG. 1;
FIG. 3 is a view of the ironing board from direction "B" shown in FIG. 1;
FIG. 4 is a view of the ironing board from the bottom;
FIG. 5 is a cross-sectional view taken along the line V--V shown in FIG. 4;
FIG. 6 is a detail of "C" shown in FIG. 5;
FIG. 7 is a view of the detail from direction "E" shown in FIG. 6;
FIG. 8 is a cross-sectional view of the ironing board taken along the line VIII--VIII shown in FIG. 4;
FIGS. 9, 10 and 11 show a detail of the safety device for transport;
FIG. 12 is an enlargement of the pedestal;
FIG. 13 is a view of the pedestal from direction "F" shown in FIG. 12;
FIG. 14 is a side elevational view of a coat hanger according to the present invention;
FIG. 15 is a cross-sectional view taken along line XV--XV of FIG. 14;
FIG. 16 is a side elevational view of an abutment cap used in the coat hanger of FIG. 14;
FIG. 17 is a side elevational view of spring used in the coat hanger of FIG. 14;
FIG. 18 show the fold-away and swivel mechanism of the sleeveboard in a schematic diagram;
FIG. 19 is an exploded view of a roller according to the present invention;
FIG. 20 is a cross-sectional view of the roller of FIG. 19;
FIG. 21 is a top plan view of the roller of FIG. 19;
FIG. 22 is a detailed bottom view of a fold-up portion of the ironing board according to the present invention; and
FIG. 23 is a cross-sectional view taken along line XXIII--XXIII of FIG. 22.
FIGS. 22 and 23 show a detail of the ironing surface that can be folded up.
FIGS. 24 and 25 illustrate the two different pivot axes for the support 36 and bracket 18.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The ironing board has a pedestal made up of two legs 6, 7 and an ironing board member 2 placed on two parallel guide rails 24 and 25.
By mounting on a wire strap 26 located on ironing board member, 2 a sleeveboard 13 is placed in such a way beneath the ironing surface 12 that it can be folded away and retracted.
At the back of the ironing board member 2 there is provided, at the same height as the ironing surface, a laundry depository 11 whose frame has a vertical offset 27. The vertical offset 27 is inserted into a holding bracket 28 disposed below the ironing board member 2 and can thus be swung to substantially coplanar with the ironing surface 12, so that in the swung-in position the depository surface 11 is located directly above the ironing surface 12, i.e., there is only a small clearance between both surfaces. At the frame of the laundry depository surface 11 there is mounted a clothes rack 10 which permits the hanging of coat hangers. The shape of the clothes rack will be discussed in detail with reference to FIGS. 14-17.
Preferably, the flatiron tray 29 consists of a braided wire 30 attached to the guide rails 24 and 25 and having an inner depository surface 31.
A whip spring 32 is provided at the braided wire 30 for the cables of an iron.
FIG. 2 is a top plan view of the ironing board from direction "A" shown in FIG. 1.
The shaping of the ironing board 2 will now be discussed in addition to the arrangements of the accessories, such as sleeveboard 13, laundry depository surface 11, clothes rack 10 and ironing board tray 29. Here, the arrangement of the fold-away seat 3, which is provided with hinges 1 is of great importance. Thus, the ironing surface 12 can, if necessary, be narrowed down to facilitate certain ironing procedures.
The laundry depository surface 11 consists of cross members 21 and a frame 20, whose end is passed into an offset 27 disposed below the ironing surface and is pivoted therein. It can be seen that the clothes rack 10 with its articulation 15 embraces the frame 20 of the laundry depository 11 and is thus pivoted on the frame 20.
In the swung-in state, the clothes rack 10 rests on the frame 20a. The laundry depository has a semicircular recess 23 in which the squeeze bottle 9 is received so as to tilt at an inclined position and rest against wire strap 22 (FIG. 3). The recess 23 is included in a squeeze bottle tray position which is part of the laundry tray. On account of this arrangement, the squeeze bottle will not leave its position even during vigorous ironing motions and can at any time be seized with a simple hand motion.
FIG. 3 is a view of the ironing board from direction "B" shown in FIG. 2. In this perspective view, the fold-away mechanism of the sleeveboard 13 is denoted with the dot-dashed directional arrow "x". The fold-away-and-swivel mechanism will be explained in detail with reference to FIG. 18. The pedestal has a common pin 33 about which pivot the two legs 6 and 7 of the pedestal.
In the lower region, the legs have a deflection 34, 35 each of which changes into a horizontal foot 4, 5. The function of the horizontal feet will be discussed in detail with reference to FIGS. 12 and 13.
FIG. 4 is a bottom view of the ironing board. The ironing board member 2 consists of a braided wire sheet 37 which rests on a square pipe frame 38. Two angular guide rails 24 and 25 rest on the braided wire sheet 37.
The square pipe frame 38 has substantially the shape of the ironing surface 12. A distinguishing feature of the frame 38 is the fact that the chamfer 59 has two corner seatings 69 that locate the hinges 1.
Parallel to the chamfer 59, an abutment means 61 is disposed beneath the ironing surface. When the locking tongue 62 is moved toward "k", locking occurs and the small ironing surface 3 can no longer be swung away. The swivel or fold-away motion is made possible by placing below the ironing surface 12 a tube 63 with pins, which are guided in the corner seatings 69. This mechanism forms the hinge.
In this embodiment, a magnet 65 is located beneath the ironing surface in order to hold the small ironing surface 3. This magnet 65 adheres to the braided wire sheet.
However, this mount can also be undone by a grid or similar device. The thwart tubular bar 67 locates guide rails 24 and 25. It is worth noticing that on account of the constructional nature of the tubular frame and of the fold-away ironing surface, the angles of slip a and b of the swung-in ironing surface are congruent.
In the swung-in state, the ironing surface 3 is retracted completely below the ironing board. The nature of the fold-away surface is again discussed in FIGS. 22 and 23.
Three pins 33, 39 and 40 are also shown in the drawings. Pin 33 is the common pin about which the legs 6 and 7 are pivoted. The pin 39 is stationary between the guide rails 24 and 25, to which the leg 6 is attached.
The pin 40 is provided with sliding ends 41 and can be moved alongside within guide rails 24 and 25, with leg 7 being attached to said pin.
This results in a shearing action of the pedestal.
A bar 42 attached to pin 40 is moved parallel to guide rails 24 and 25. A sliding of the pedestal is made possible by actuating the grip lever 43. Tip 44 (FIGS. 5-8) of bar 42 is guided in a recess 45 (FIGS. 5-8) of a piece of angle sheet iron.
There is disposed at 40 the safety device 14 for transport, into which leg 6 is pressed and is held by lugs FIGS. 24 and 25 illustrate the two different pivot axes for the support 36 and bracket 18 53 (FIGS. 9-11). Wire straps 26 of the sleeveboard are discussed with reference to FIG. 18, as mentioned earlier.
FIG. 5 is a cross-sectional view of the ironing board taken along the line V--V of FIG. 4.
Ironing board member 2 has a braided wire sheet 37 which rests on a square pipe frame 38. Ironing surface 12 is provided with a felt lining 47 and slip-on cover 48.
Grip lever 43 changes into a fulcrum 50 which is mounted in guide rails 24 and 25.
Fulcrum 50 is surrounded by angle iron piece 46 which is preloaded by a spring 51 (FIG. 6), into whose recess 45 bar 42 is guided.
FIG. 6 shows a detail of "C" as shown in FIG. 5 and depicts guide rail 25 with fulcrum 50 which is surrounded by angle iron piece 46. A spring 51 preloads angle sheet iron and the angle sheet iron 46 guides bar 42 in its recess 45.
FIG. 7 is a view of the detail of FIG. 6 from direction "E". It can be seen that bar 42 has a taper 52, which moves freely within recess 45, even if grip lever 43 is not actuated.
Therefore, in order to prevent the pedestal from flipping out inadvertently, the safety device for transport depicted in FIG. 4 is placed on pin 40.
FIG. 8 is a cross-sectional view of the ironing board taken along the line V--V of FIG. 4. Here, pin 40 can be seen with the safety device for transport, whose lugs 53 clamp leg 6 into position. Sliding ends 41 enable pin 40 to travel between guide rails 24 and 25 in a longitudinal direction.
FIGS. 9, 10 and 11 show in various views the safety device for transport, which essentially comprises a base 57 and two retaining lugs 53. Base 57 has a semicircular recess 58 provided for locating the pin 40. Made integral with base 57 are the two elastic lugs 53 which, when leg 6 is pressed on, deflect to such a degree that lugs 53 embrace leg 6 and clamp the same into position.
FIG. 12 is a schematic diagram showing the geometry of pedestal legs 6 and 7. The horizontal foot 4/5 is telescopic and can be pulled out in direction "Y" so as to ensure improved stability. For steadiness, a corner piece of frame 55 is interposed between pedestal legs 6 and 7 and feet 4 and 5.
FIG. 13 is a schematic view of foot 5 from the direction "F" shown in FIG. 12. Roller 8 placed at the horizontal foot 5 is mounted eccentrically at foot 5, so that small irregularities of the floor can be compensated by turning the roller 8. Here, the eccentricity can be achieved selectively by the shape of the roller or of the foot.
FIGS. 14-17, 24, and 25 show the clothes rack 10. It embraces with its hinge 15 frame 20 (FIG. 2) of laundry depository 11 and is thus pivotally connected thereto so that the support linkage 36 is pivotal between horizontal and vertical positions. The vertical support linkage 36 has a length such that it rests in the swung-in state (horizontal position) on frame 20a of laundry depository or tray 11 through a rearward extension 19 of the bracket 18.
Hinged bracket 18 has on both sides a slot 54 through which is passed a spring or rivet and movably attaches hinged bracket 18 to support linkage 36 and to abutment cap 17 (FIG. 16). Abutment cap 17 is inserted into the end of linkage 36 and formed such that after pushing up bracket 18 toward "b", the bracket 18 then pivoted on its rounded joint 60. After pressing bracket 18 downwardly toward "d" when bracket 18 is substantially perpendicular to the support linkage 36, the bracket abuts with its shoulder 49 edge 56 and prevents collapsing, even when loaded with articles of clothing, i.e., when a force "F" is present. Bracket 18 has several notches 64 for suspending coat hangers and the latter are prevented by pushed-up lug 67 from falling off forwardly.
When bracket 18 is being swung in, bores 68 on both sides engage lugs 70 of spring 71 disposed in support linkage 36.
The semicircular shape of bracket 18, as shown in FIG. 15, assures complete surrounding of support linkage 36 by bracket 18, so that both parts appear as one element in the swung-in state.
FIG. 16 shows abutment cap 17 in detail, in which rounded joint 60 and abutment means 56 are illustrated. Slot 72 locates the common splint or rivet.
Abutment cap 17 lies inside support linkage 36 after assembly.
FIG. 17 shows spring 71 in detail. Preferably, it is V-shaped and has at its ends two lugs 70, which project through the wall of support linkage 36 and engage in their bores 68 when bracket 18 is being swung into position.
FIG. 18 shows the principle of the flap-hinging and swinging mechanism sleeveboard 13.
Here, two wire straps 26 disposed parallel to two distance spacers 73 are matched to two fulcrums 26a beneath sleeveboard 13.
Wire straps 26 are so deflected that storage below and, for ironing, above the ironing surface 12 is possible. By pulling sleeveboard toward "A", the latter is pulled ahead below the board. By rotating the fulcrums 26a within tubes 74, the sleeve board 13 moves upwardly toward "B", the height of the sleeveboard is altered and it is positioned over ironing surface 12 when being pushed in toward "C".
The wire straps are retracted when being pushed into tubes 74 disposed below the ironing surface.
FIGS. 19-21 show the details of the eccentric rollers 8. Each eccentric roller 8 consists of a body 75 with eccentrically disposed pin, from which extends an integral cylinder 76 surrounded by a circular tube 77. Body 75 is provided with grooved elevations 78 for stability. A facing cap 87 is disposed on the end surface. An inner cylinder 79 is inserted into circular tube 77 and locks by its lugs 80 inner cylinder 79 to prevent it from rotating, because lugs 80 engage in grid 81 located in circular tube 77. Not until body 78 is pulled at roller 8 toward "x"--during which spring 82 surrounding cylinder 76 is compressed--can body 78 be rotated. Here, a safety disc 83 is disposed at the end of the cylinder. Level equalization is possible on account of the eccentric arrangement of the pin.
FIGS. 22 and 23 again show the flap-hinge surface of the ironing board (FIG. 22) and a cross-section taken along the line XXIII--XXIII (FIG. 23). A distinguishing feature of the invention is the fact that upset wall 84 of flap-hinge surface 3 has a recess 85/86. When flap-hinge surface 3 is moved toward "v", it will be enabled to retract completely within ironing board 2 (dot-dash line) and not to stand out. This is essentially made possible by the arrangement of the hinges, which consist of a pin (1) disposed within tube 63 and corner seating 69. It assures rotation toward "v".
It follows from the invention that this ironing board solves almost all of the ergonomics problems.
The arrangement of all accessories, such as flatiron tray with cables, swivel laundry depository with coat hanger and squeeze bottle tray, fold-away sleeveboard, fold-away ironing surface, arrangement of the safety device for transport and the shape of the pedestal, all of which make ironing in the sitting position possible since the legs are deflected in the knee area, as well as the telescopic-type adjustment of length and height of the vertical feet meet all of the requirements of an ironing board that has been perfected from the ergonomics standpoint. | An ironing board apparatus includes an ironing board member mounted on a pedestal. The ironing board member has a main portion and a foldaway corner portion pivotally connected to the main portion by a hinge. A retractable sleeveboard is connected to the ironing board member for movement into position with respect to the ironing board. A flat iron tray is retractably mounted to the ironing board, as well as a laundry tray which is pivotally connected to the ironing board member. | 3 |
FIELD OF THE INVENTION
This invention relates to rifles for military and civilian sporting use.
BACKGROUND
Modern sporting rifles as well as military rifles and carbines must be robust for reliable operation, and lightweight to permit carry without excessive fatigue. Significant reduction in rifle weight has been previously achieved by replacing wood with polymer material for components such as the shoulder stock and fore stock. Such designs have been successful because the use of polymer material for these elements does not compromise the robustness or reliable operation of modern firearms.
However, components such as the receiver and its associated assemblies such as the bolt carrier and barrel still account for a significant portion of the weight of a firearm, as it has not been thought feasible to substitute polymer for such parts which experience heat, pressure and wear from reciprocating motion. To meet the harsh requirements of operation many receiver designs are machined from a solid aluminum billet, and thus represent, in addition to significant weight, a significant production cost, as the machining is complex and constrained by tight tolerance requirements. There is clearly a need to further reduce rifle weight and simplify production without compromising the performance of the modern combat or sporting rifle.
SUMMARY
The invention concerns a bearing for a bolt carrier in an upper receiver of a firearm having a charging handle, a fire control mechanism and a magazine. In one example embodiment the bearing comprises a tube positionable within the upper receiver. The tube has a sidewall defining an inner surface supporting the bolt carrier and motion thereof between an open position and a battery position. A first opening in the sidewall defines an ejector port. A second opening in the sidewall is positioned to permit engagement between the bolt carrier and the charging handle. A third opening in the sidewall receives the fire control mechanism or the magazine.
By way of example a fourth opening in the sidewall receives the fire control mechanism or the magazine. In an example embodiment, the tube has a buffer tube radius for attaching a buffer tube to the tube. In a specific example the second opening is positioned diametrically opposite to the third opening. In a further specific example the second opening is positioned diametrically opposite to the fourth opening. In another example the first opening is positioned angularly offset from the second opening about a longitudinal axis of the tube. In an example embodiment the second opening comprises a slot extending lengthwise along the tube, one end of the slot being open. In a further example the third and fourth openings are contiguous with one another. In another example the fourth opening is wider than the third opening.
By way of example one end of the tube comprises screw threads. In a particular example the screw threads are positioned on the inner surface. In another example the screw threads are positioned on an outer surface of the tube. An example embodiment further comprises an aperture in the sidewall for permitting engagement between the bolt carrier and a forward assist button.
The invention also encompasses an upper receiver of a firearm having a bolt carrier, a charging handle, a fire control mechanism and a magazine. In this example embodiment the upper receiver comprises a metal tube having a sidewall defining an inner surface supporting the bolt carrier and motion thereof between an open position and a battery position. A polymer shroud surrounds at least a portion of the metal tube. A first opening, positioned in the sidewall and a first opening, positioned in the polymer shroud overlying the first opening in the sidewall define an ejector port.
By way of example the invention further comprises a second opening in the sidewall and a second opening in the polymer shroud overlying the second opening in the sidewall. The second openings are positioned to permit engagement between the bolt carrier and the charging handle.
An example embodiment further comprises a third opening in the sidewall for receiving the fire control mechanism or the magazine. Another example comprises a fourth opening in the sidewall for receiving the fire control mechanism or the magazine. Another example embodiment comprises a rail mounted on the shroud. The rail and extends lengthwise along the tube and comprises a plurality of ribs oriented transversely to a longitudinal axis of the tube. Further by way of example the shroud comprises an outwardly projecting surface positioned adjacent to the ejector port. Another example further comprises a housing extending from the shroud for receiving a forward assist button. In this example the metal tube comprises an aperture aligned with the housing for permitting engagement between the bolt carrier and the forward assist button.
By way of example the invention further comprises first and second lugs positioned at opposite ends of the shroud for attaching the shroud to a lower receiver. Another example embodiment of the invention comprises a buffer tube radius for attaching a buffer tube to the metal tube.
By way of example, the first openings are positioned angularly offset from the second openings about a longitudinal axis of the metal tube. In a further example, the second opening in the sidewall of the metal tube comprises a slot extending lengthwise along the metal tube, one end of the slot being open.
In an example embodiment, one end of the metal tube comprises screw threads. In a specific example the screw threads are positioned on the inner surface of the metal tube. In another example embodiment, the screw threads are positioned on an outer surface of the metal tube.
The invention also encompasses firearm having a bolt carrier, a charging handle, a fire control mechanism and a magazine. In an example embodiment the firearm comprises an upper receiver comprising a metal tube having a sidewall defining an inner surface supporting the bolt carrier and motion thereof between an open position and a battery position. A polymer shroud surrounds at least a portion of the metal tube. A first opening is positioned in the sidewall and a first opening in the polymer shroud overlies the first opening in the sidewall. The first openings define an ejector port.
In an example embodiment a second opening in the sidewall and a second opening in the polymer shroud overlying the second opening in the sidewall are positioned to permit engagement between the bolt carrier and the charging handle.
In another example a third opening in the sidewall receives the fire control mechanism or the magazine. In a further example the invention comprises a fourth opening in the sidewall for receiving the fire control mechanism or the magazine. In a specific example embodiment a rail is mounted on the shroud and extends lengthwise along the tube. The rail comprises a plurality of ribs oriented transversely to a longitudinal axis of the tube. By way of example the shroud further comprises an outwardly projecting surface positioned adjacent to the ejector port.
In an example embodiment the firearm further comprises a housing extending from the shroud for receiving a forward assist button. The metal tube comprises an aperture aligned with the housing for permitting engagement between the bolt carrier and the forward assist button.
By way of further example, first and second lugs are positioned at opposite ends of the shroud for attaching the shroud to a lower receiver. A particular example comprises a buffer tube radius for attaching a buffer tube to the metal tube. In a specific example the first openings are positioned angularly offset from the second openings about a longitudinal axis of the metal tube. In another example the second opening in the sidewall of the metal tube comprises a slot extending lengthwise along the metal tube, one end of the slot being open. By way of example, one end of the metal tube comprises screw threads. In a specific example the screw threads are positioned on the inner surface of the metal tube. In another example, the screw threads are positioned on an outer surface of the metal tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right side view of an example rifle according to the invention;
FIG. 1A is a longitudinal sectional view taken from within the ellipse of FIG. 1 ;
FIG. 2 is a right side view of the lower receiver of the rifle shown in FIG. 1 ;
FIG. 3 is a right side view of the upper receiver of the rifle shown in FIG. 1 ;
FIG. 4 is an exploded side view of the upper receiver of the rifle shown in FIG. 1 ;
FIG. 5 is an isometric view of an example bearing used in an upper receiver of a rifle;
FIG. 6 is an isometric view of the bearing shown in FIG. 5 rotated 90° about its longitudinal axis in a clockwise direction; and
FIG. 7 is an isometric longitudinal sectional view of a portion of an example upper receiver according to the invention;
DETAILED DESCRIPTION
FIG. 1 depicts an example embodiment of a rifle 10 according to the invention. Rifle 10 may be capable of automatic or semi-automatic operation and comprises a lower receiver 12 (see also FIG. 2 ) which houses a fire control mechanism 14 (see also FIG. 4 ) and has a magazine well 16 which receives an ammunition magazine 18 . An upper receiver 20 (see also FIG. 3 ) is attached to the lower receiver 12 . The upper receiver houses a charging handle 22 , a bolt carrier 24 (see also FIG. 4 ) and may also house a forward assist button 26 .
During operation of the rifle 10 , the bolt carrier 24 (see FIG. 4 ) reciprocates within the upper receiver 20 between “battery”, a position wherein the bolt 28 on the bolt carrier 24 is engaged with the breech of barrel 30 (see FIG. 1A ), and an open position, where the bolt 28 is disengaged from the breech and the bolt carrier 24 is retracted away from the breech. In battery, a round chambered in the breech may be discharged. Upon discharge, the bolt carrier 24 moves from battery to the open position, extracting and ejecting the spent cartridge and resetting the fire control mechanism 14 along the way. Motion of the bolt carrier 24 from battery to the open position also compresses a return spring (not shown) acting on the bolt carrier. As the bolt carrier 24 moves back into battery (driven by the return spring) it strips a round from the magazine 18 and chambers it in the breech of barrel 30 completing the cycle. Energy for moving the bolt carrier 24 through this cycle (in either automatic or semi-automatic operation) is provided by the ammunition itself using one of at least three well understood modes of operation commonly known as “recoil”, “blow-back”, and “gas” operation. A round is initially chambered and the fire control mechanism 14 is initially set by drawing and releasing the charging handle 22 , which draws the bolt carrier 24 from battery to the open position and permits the bolt carrier to move back into battery, driven by the aforementioned return spring (not shown).
Thus the upper receiver 20 must support the bolt carrier 24 as it moves between battery and the open position but also allow the various components, including the fire control mechanism 14 , the magazine 18 , the charging handle 22 , and the forward assist button 26 (when present) to interact with the bolt carrier. The upper receiver 20 must also provide an ejection port 32 to permit ejection of the spent cartridge. In the upper receiver 20 according to the invention the bolt carrier 24 is supported by a bearing 34 , shown in FIGS. 4-6 . Bearing 34 comprises a metal tube 36 , which may be formed from aluminum, steel or other durable metals. Tube 36 in this example has a round cross section defined by a sidewall 38 . Sidewall 38 also defines an inner surface 40 which supports the bolt carrier 24 in its reciprocal motion between battery and the open position. Tube 36 is sized in both length and inner diameter so that tilting of the bolt carrier 24 relative to the longitudinal axis 52 of tube 36 is mitigated to ensure smooth motion during operation for reliability.
As shown in FIGS. 4 and 5 , an ejector port 42 is provided within the sidewall 38 to permit ejection of spent cartridges from the receiver. An aperture 44 is also provided within the sidewall 38 to permit the forward assist button 26 to engage the bolt carrier 24 and drive it into battery when the return spring fails to do so. FIG. 5 illustrates yet another opening 46 in the sidewall 38 which is positioned to permit the charging handle 22 to engage the bolt carrier 24 . FIG. 6 illustrates additional openings 48 and 50 . Opening 48 permits at least a portion of the fire control mechanism 14 (see FIG. 4 ) to extend into the tube 36 and interact with the bolt carrier 24 . Opening 50 permits the magazine 18 to extend into the tube 36 so that rounds can be stripped and chambered as the bolt carrier 24 moves into battery.
As shown by way of example in FIGS. 5 and 6 , the opening 46 for charging handle 22 is diametrically opposite to the openings 48 and 50 for the fire control mechanism 14 and the magazine 18 . This configuration is dictated by the layout of the rifle 10 shown in FIG. 1 , wherein the charging handle 22 is positioned on the upper receiver 20 and substantially aligned with the fire control mechanism 14 and the magazine well 16 which receives the magazine 18 , all of which are housed in the lower receiver 12 . Ejector port 42 (see FIGS. 4 and 5 ) is angularly offset from the charging handle opening 46 about the longitudinal axis 52 of the tube 36 to direct the spent cartridges to the right side of the rifle 10 . Other arrangements of the openings in tube 36 are of course feasible to accommodate other rifle configurations. The openings are further shaped and dimensioned commensurate with their respective functions. To this end, opening 46 in this example comprises an elongate slot to accommodate the necessary range of motion of the charging handle 22 and bolt carrier 24 along the tube 36 . In this example one end 46 a of the slot formed by opening 46 is open. Similarly, openings 48 and 50 are sized to accommodate the fire control mechanism and magazine, respectively, opening 50 being wider than opening 48 as a result. The openings 48 and 50 may be contiguous with one another as shown.
The simplicity of the bearing 34 allows the various openings to be conveniently formed by laser machining techniques. Traditional machining techniques are of course also feasible.
As further shown in FIG. 1A , tube 36 may have screw threads 54 positioned at the end which interfaces with the barrel 30 (see also FIG. 1 ). Threads 54 may be on the inner surface 40 of the tube 36 (shown) or on the outer surface 56 . Additionally, as shown in FIG. 6 , a buffer tube radius 56 may also be part of tube 36 for accommodating a buffer tube (not shown), which contains the return spring (not shown).
Another part of the upper receiver according to the invention is the polymer shroud 58 , an example being shown in FIG. 4 . Shroud 58 is formed from a polymer such as fiber reinforce nylon which, as shown in FIGS. 3 and 7 , is injection molded around a tube 36 that has already been machined and finished. In production a machined, finished tube 36 is placed in a mold for the upper shroud, the mold is closed, and the polymer is injected into the mold in a co-molding process that joins shroud and tube. Injection molding is advantageous because it permits features having complex geometries to be incorporated into the upper receiver while avoiding costly and time consuming machining. The example shroud 58 includes a so-called “Picatinny” rail 60 that extends lengthwise along the tube 36 and has a plurality of transverse ribs 62 . Also shown in FIG. 3 are a housing 64 for the forward assist button 26 and an outwardly projecting surface 66 adjacent to the ejector port 42 for deflecting ejected cartridges. Lugs 68 for attaching the upper receiver 20 to the lower receiver 12 may also be injection molded as part of shroud 58 .
Injection molding also allows openings to be formed in the shroud 58 that correspond to openings in the tube 36 . As shown in FIGS. 3 and 4 , opening 70 in shroud 58 aligns with the ejector port opening 32 in the tube 36 ; opening 72 in the shroud aligns with the opening 46 for the charging handle 22 ; and opening 74 aligns with aperture 44 for the forward assist button 26 . In the example shroud 58 the region between the lugs 68 is substantially open to permit the fire control mechanism 14 and the magazine 18 to be received within respective openings 48 and 50 in the sidewall 38 of tube 36 when the upper receiver 20 is mounted on the lower receiver 12 and the magazine 18 is inserted into magazine well 16 .
A rifle having a polymer upper receiver co-molded with a tube comprising a bearing for supporting and guiding a bolt carrier provides numerous advantages over traditional rifles wherein the receiver is machined from a billet. Such rifles will have reduced weight and more economical and rapid production without sacrificing reliability or robustness. | A metal tube provides a bearing for a bolt carrier in a rifle. The tube is machined to provide openings and co-molded with a polymer outer shroud to form a lightweight composite upper receiver. The tube has an inner surface that supports the bolt carrier in its reciprocal motion during cycling of the rifle action during firing. The length and diameter of the tube are designed to prevent tilt of the bolt carrier during operation. | 5 |
TECHNICAL FIELD
This invention relates to the inhibition of the growth of zebra mussels (Dreissena Polymorpha) which have recently infested the Great Lakes and nearby rivers and other waters. It involves the use of certain thermosetting materials as structural or surface materials in areas where the zebra mussels are not desired. The areas of concern can be either stationary, such as piers, power plant cooling water intakes, and the like, or moving, such as boat hulls or buoys. The thermosetting materials are unsaturated polyesters copolymerized with N-phenyl maleimide or N-cyclohexyl maleimide.
BACKGROUND OF THE INVENTION
Zebra mussels were first discovered in American waters in Lake St. Clair in 1988, ["Infestation of the Monroe Power Plant by the Zebra Mussel (Dreissena Polymorpha)", Kovalack, W. P., Longton, G. D., Smithee, R. D., Proceedings of the American Power Conference, Chicago, Ill., 1990]. It is believed that the mussel larvae were dumped into the water with a European or Western Asian ship's ballast water in 1985. The mussels have spread quickly throughout the Great Lakes Basin and are reasonably expected to infest waterways in most of the United States including Florida but excluding most of the other Southern and Southwestern states and to infest most of southern Canada. They have spread throughout most of Europe with the exception of northern Scandinavia, the Iberian Peninsula and Italy. They are also in western Asia where they originally inhabited the Ural River and Caspian Sea but now cover almost all of Russia, extending into Turkey ["Impact of the European Zebra Mussel Infestation to the Electric Power Inudstry", McMahon, R. F., Tsou, J. L., Proceedings of the American Power Conference, Chicago, Ill., 1990].
Zebra mussels float through the waters in a free swimming planktonic veliger state. They attach to any hard surface with byssal threads. The byssus contains up to 200 threads which are difficult to remove from a surface even after death. They may attach to other mussel shells and form large clumps of mussels which threaten to block intake lines of raw water supplying power plants and municipal water authorities ["Control of Zebra Mussels at CEI Facilities", Barton, L. K., Proceedings of the American Power Conference, Chicago, Ill., 1990].
Workers in the art have attempted to control macroinvertebrates generally by dissolving into the environment of the target organisms various amines and/or quaternaries. See, for example, U.S. Pat. No. 4,816,163 to Lyons et al, U.S Pat. No. 4,857,209 to Lyons et al, U.S. Pat. No. 4,906,385 to Lyons et al, U.S. Pat. No. 4,970,239 to Whitekettle et al, and U.S. Pat. No. 4,579,665 to Davis et al. When zebra mussels received attention, they also were attacked through the use of various water-soluble materials, such as the halides of Ekis, Jr. et al U.S. Pat. No. 5,141,754, the particular quaternary ammonium compounds of Gill in U.S. Pat. No. 5,128,050, and Muia et al in U.S. Pat. No. 5,062,967, and the quaternary ammonium polymers of Muia et al in U.S. Pat. Nos. 5,015,39 and 5,096,601. Bollyky et al in U.S. Pat. No. 5,040,487 use ozone. All such approaches are to treat the aqueous environment in which the zebra mussels live.
Generally, the environments treated are open to circulation of water, and accordingly, the maintenance of an effective concentration of such materials requires continuous or frequent feeding, which means a risk must be calculated as to the tolerance of other living things in the environment for the materials introduced, even if the effective concentrations to be maintained are relatively low.
SUMMARY OF THE INVENTION
We have found that zebra mussels are reluctant to settle on surfaces made of a complex polymer or resin comprising about 5% to about 89% of a more or less conventional unsaturated polyester, about 1-40% by weight of a maleimide, up to about 20% of methacrylic acid or a lower ester thereof, and about 10-40% of a polymerizable monomer such as styrene or vinyl toluene. Various generally inert fillers such as kaolin clay, aluminum trihydrate, calcium carbonate, glass fibers and the like may be added to the resin depending on the physical properties desired. Where the maleimide is N-phenyl maleimide, the compositions may be as described in Piermattie et al U.S. Pat. No. 4,983,669; this patent also contains a description of the unsaturated polyesters useful in our invention, and accordingly, the entire specification of U.S. Pat. No. 4,983,669 is incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
Example 1
In a controlled laboratory experiment, approximately 113 mussels in the form of adults were placed in boxes which were set in a temperature controlled aquarium. They were given the choice of attaching to a vertical wall of the box constructed of polystyrene, a panel of cured polyester containing either 3% or 10% by weight copolymerized N-phenylmaleimide, other mussel shells or not attaching at all. After three weeks, the results were:
______________________________________ Poly-3% NPM 10% NPM styrene Shells Floating______________________________________# Mussels 4 0 54 20 35attached______________________________________
Example 2
In a controlled laboratory experiment, 51 mussels were placed in each of several boxes which were set in a temperature controlled aquarium. Boxes were made up of either polystyrene, polystyrene lined with panels made up of 3% NPM-polyester panels or polystyrene lined with 10% NPM-polyester panels, so that the mussels did not have a choice of surface on which to settle.
Mussels attach to vertical surfaces first by extending long, thick byssal threads which seem to be temporary. Later they extend short, thinner permanent threads to the surface. The results (average number of threads per mussel) of this experiment which lasted for six weeks are:
______________________________________3% NPM Box 10% NPM Box Polystyrene Box______________________________________total 85.9 80 36.7threadstype ofthreadtemp. 35.1 29.4 5.6perm. 50.8 50.6 31.1______________________________________
Example 3
Through the use of a Scanning Electron Microscope, the point of attachment of the byssal thread to the surface could be observed, filmed and photographed. The threads open up to a uniform circular foot referred to as a plaque which is the point of attachment. The plaques on the polystyrene surfaces were in fact circular and uniform. All of the plaques on the panels which incorporated NPM into the polyester had jagged irregular perimeters and were non-uniform. We conclude that for an as yet unknown reason, the material that we have developed affects the nature of attachment. | Growth of zebra mussels on a surface is inhibited by making the surface from an unsaturated polyester having copolymerized therein about 1-40% N-phenyl maleimide. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to dispatching systems, and particularly to a dispatching systems for dispatching lots in the manufacture of semiconductor integrated circuit devices.
2. Description of the Prior Art
A typical process for manufacturing semiconductor integrated circuit devices may include more than one hundred process steps, which are usually classified into following categories: diffusion; photolithography; etching; ion implantation; deposition; and sputtering. Among these categories, processes such as diffusion or deposition generally require a long process time to perform. Thus, these long process time processes are commonly performed on several wafer lots (commonly referred to as a batch). For example, a typical diffusion process step takes four to twelve hours for simultaneously processing a batch of up to six lots.
Scheduling policy thus becomes an important task in managing a production system. For example, a scheduling policy may be optimized to: maximize throughput of wafers out of the production system or factory; minimize the average time wafers spend in the factory to reduce the amount of work-in-progress (WIP); or maximize the utilization of machines (also referred to as tools). One aspect of production scheduling is controlling the release of pending jobs onto the processing floor (i.e., lot release). Another aspect of production scheduling is called lot dispatching, which deals with the control of jobs already on the processing floor. More specifically, lot dispatching concerns scheduling which lot(s) of the WIP are to be processed when a machine becomes available.
FIGS. 1A to 1C illustrate the concept of lot dispatching. Referring to FIG. 1A, a group of WIP lots 10 are waiting to be dispatched into the machine 12 once the machine 12 becomes available. In this example, there are n lots in the group of lots 10. Further, a group of lots 14 (in this example, m lots) are expected to arrive at the machine 12 at a known time. The time period defined by the time at which the machine becomes available and the time at which the lots 14 arrive at the machine 12 is referred to herein as the definite period for the lots 14.
FIG. 1B shows the situation in which the n lots 10 are immediately dispatched into the machine 12 without waiting for the expected m lots 14. This situation may result in inefficient use of the machine 12 when the definite period for the lots 14 is small and m is relatively large. FIG. 1C, however, illustrates the situation in which the machine 12 waits idle during the definite period, and then processes the total (n+m) lots together. This situation may result in inefficient use of the machine 12 if the definite period is long and m is relatively small.
In one typical conventional lot dispatching method used in a semiconductor wafer manufacturing line, the arrived lots are stored to await lot dispatching to various machines or tools on a batch basis. The pending lots are typically prioritized at this stage of the production process. A worker or operator then dispatches the lots to various machines as the machines become available. In this conventional method, the worker relies on his or her experience and judgment to decide whether to immediately dispatch a group of lots to the available machine or else wait the definite period for a group of expected lots. As can be expected, this subjective method often results in inefficient use of the processing machines. Further, as this conventional dispatching method is established by the operator through trial-an-error over a relatively large period of time, the established optimal criteria needs to be redetermined from the beginning when a condition, such as temperature, period of process or types of gasses used by the machine changes.
Accordingly, there is a need for an optimization-based dispatching rule for use in manufacturing semiconductor integrated circuit devices that use machines that require batch run and/or long process time.
SUMMARY OF THE INVENTION
In accordance with the present invention, a lot dispatching method and apparatus is provided for efficiently dispatching lots to a machine during the manufacture of semiconductor integrated circuit devices without relying on the subjective experience and judgment of a human operator. In one embodiment, the dispatching method and apparatus are advantageously used to dispatch lots into a machine when one or more WIP lots (e.g., n lots) are available to be processed when the machine becomes available and one or more other WIP lots (e.g., m lots) are expected after a definite period. The method and apparatus are used to decide whether to dispatch the n lots immediately or else wait for the definite period to dispatch the n lots combined with one or more lots from the group of m lots, so that use of the machine may be optimized
In one embodiment, the average process time T and average number of lots per batch a are determined for the machine. From the values of T and a, the maximum allowable time for waiting for additional lots is calculated. More specifically, the maximum allowable waiting time for one additional lot up to the maximum batch size B of the machine is calculated according to the equation:
Tmax.sub.k =k(T/a) (1)
where Tmax k is the maximum allowable waiting time for k additional lot(s), for each value of k between the integers between one and B, inclusive. The term (T/a) in equation 1 represents the average time needed to process a lot in one batch run of the machine. Thus, the maximum waiting time for the additional k lots is set to the k times (T/a) so that if the batch run is delayed until the additional k lots arrive, the average time per lot remains unchanged for this particular batch run. It will be appreciated that if this batch run is delayed longer than k(T/a), then this batch run will have a larger average time per lot and, thus, will be relatively less efficient. On the other hand, if this batch run is delayed less than k(T/a), then this batch run will have a smaller average time per lot and, thus, will be relatively more efficient.
The values of Tmax k calculated for each value of k are then stored. Then, when the machine becomes available, the definite period of the next expected m lots is compared to the stored values of Tmax k . If the definite period of the additional m expected lots is greater than the Tmax k for k additional lots (k being equal to m to the extent that n+m does not exceed B), then the n pending lots are dispatched immediately into the machine. Conversely, if the definite period of the m additional lots is less than the Tmax k , the n lots are not dispatched into the machine and, instead, the machine is kept idle until the m additional lots arrive. When the m additional lots arrive, the above process is repeated. Of course, in this second iteration, the number of pending lots is now equal to n+k lots. It will be appreciated that if n+k is equal to B, then the n+k lots are immediately dispatched into the machine as soon as the m additional lots arrive at the machine.
In one embodiment of the present invention, the dispatching apparatus includes a controller that is used to monitor: (i) the machine (also referred to herein as the succeeding process); (ii) the n WIP lots waiting to be processed by the machine; and (iii) a preceding machine (or the preceding process) from which the group of m expected WIP lots come from before being sent to the succeeding process. Through this monitoring, the controller determines T, a (in number of lots), and Tmax k (for k between one and B, inclusive), which the controller then compares to definite period for the expected m lots. In this embodiment, the controller determines whether to immediately dispatch the n lots or else wait for the m expected lots, as described above, and signals the human operator accordingly.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of his invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIGS. 1A to 1C illustrate a conventional lot dispatching process;
FIG. 2A is a block diagram of a portion of a dispatching system according to one embodiment of the present invention;
FIG. 2B is a time line illustrating how a group of WIP lots flow through a manufacturing process; and
FIG. 3 is a flow diagram illustrating two embodiments of a lot dispatching method according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2A shows a block diagram of a portion of a dispatching system 18 for use in manufacturing semiconductor integrated circuit devices having batch run and/or long process time processes. A controller 20 is used to monitor the status of: (i) a group of waiting WIP lots 22; (ii) a preceding process 24; and (iii) a succeeding process 26. In this embodiment, the controller 20 is a standard personal computer, although any suitable computer, or programmable controller or processor can be used. The controller 20 is programmed with the maximum batch size B of the succeeding process 26. Through monitoring the waiting lots 22, the preceding process 24 and the succeeding process 26, the controller 20 determines: (a) the number of lots n in the waiting lots 22; (b) the average process time T of succeeding process 26; (c) the number of lots m in the expected lots in the preceding process 24; (d) the definite period t m of the expected lots in the preceding process 24; and (e) the average number of lots a per batch of the succeeding process.
FIG. 2B illustrates an example of the timing of pertinent stages of the flow of WIP through the preceding and succeeding processes 24 and 26. Referring to FIGS. 2A and 2B, at time t, there are n lots of waiting WIP 22A and the succeeding process 26 is available. At this point, the preceding process 24 has a definite period of t m . Therefore, at time (t+t m ), the preceding process 24 (FIG. 2A) has finished processing the expected lots, thereby making available an additional m lots of WIP 22B. If at time t the controller 20 immediate dispatches the WIP 22A into the succeeding process 26, the n lots of WIP 22A exit the succeeding process 26 at the time (t+T). However, if the controller 20 holds the WIP 22A until the WIP 22B becomes available at time (t+t m ), the number of WIP 22B available to the succeeding process 26 is increased by m lots to a total of (n+m) lots. These (n+m) lots are then dispatched into the succeeding process 26, which then exit the succeeding process 26 at the time (t+t m 30 T).
The controller 20 dispatches the WIP 22A to the succeeding process 26 at the time t, or else dispatches the WIP 22A and 22B together to the succeeding process 26 at the time (t+t m ), in accordance with a lot waiting rule (LWR) of the present invention. One embodiment of the LWR is described below in conjunction with FIG. 3.
FIG. 3 is a flow diagram illustrative of a LWR of the present invention. Referring to FIGS. 2A and 3, one embodiment of the LWR is implemented as follows. In a step 30, the average process time T of the succeeding process 26 is determined over a suitable number of past cycles of the succeeding process. Similarly, the average number of lots a per batch of the succeeding process 26 is calculated.
Alternatively, the average process time T can be programmed and stored in the controller 20 as fixed data for processes in which the average process time remains substantially constant. In a further refinement, for a process in which the process conditions often change from cycle to cycle, the average process time T can be dynamically updated by, for example, looking up a table stored in the controller 20 that is indexed by the process conditions.
Next, the number of lots k of the expected m lots in the preceding process 24 that can be combined with the n pending lots is determined in a step 32. This determination of the allowable number k' is done by comparing, in a step 320, the maximum batch size B of the succeeding process 26 with the sum of the pending WIP n and the expected WIP m. If the total number (m+n) is less than or equal to the batch size B, the number of allowable lots k is equal to m (step 322); that is, all the lots in the preceding process 24 can be dispatched into the succeeding process 26, depending on the value of the definite period t m , as described below. Otherwise, the number of allowable lots k is equal to (B-n) lots (step 324). In this situation, some, if not all, of the m lots of the preceding process 24 will not be dispatched with the pending n lots.
In order to optimize the efficiency of the succeeding process 26, a lot waiting rule (LWR) according to the present invention is applied to the definite period tm of the k allowable lots. In this embodiment, the LWR criteria or allowable waiting time for the succeeding process 26 is derived in a step 34 as k(T/a). If the definite period t m exceeds the LWR criteria k(T/a), a step 36 is performed in which the n pending lots are dispatched to the succeeding process 26 immediately. Otherwise, a step 37 is performed in which the n pending lots are held until the m expected lots arrive from the preceding process 24. When the m expected lots arrive, (n+k) lots are then dispatched to the succeeding process 26.
In an alternative embodiment, the controller 20 may calculate a look-up table indexed by the value of the additional allowable lots k. Table 1 below illustrates an example of the look-up table, which is calculated using equation 1 for values of k from one to six, inclusive. It is understood that the values of a and T are known, and the maximum allowable waiting time is assumed T if 6(T/a) is greater than T.
TABLE 1______________________________________maximum allowable waiting time Tmax.sub.kk = 1 k = 2 k = 3 k = 4 k = 5 k = 6______________________________________(T/a) 2(T/a) 3(T/a) 4(T/a) 5(T/a) 6(T/a)______________________________________
Then in the step 34, the controller 20 compares the definite period t m with the value in the look-up table corresponding to the value of k calculated in the step 32. The look-up table may be updated periodically to account for changes in the average number of lots a per batch and/or the average process time T.
The maximum allowable waiting time k(T/a) represents the average time needed to process k lots in a batch run. Thus, if the definite period is equal to the maximum waiting, the average time per lot for this batch run is not changed. Of course, if this batch run is delayed by more than this maximum allowable waiting time to process the k additional lots, this batch run will have a larger time per lot than the average (i.e., T/a), thereby decreasing the throughput of the succeeding process 26. On the other hand, if the batch run is delayed by less than this maximum allowable waiting time to process the k additional lots, this batch run will have a smaller time per lot, thereby increasing the throughput of the succeeding process 26.
Stated in a different manner, this LWR tends to optimize the usage of the succeeding process 26 because a high value for k indicates that there are few pending lots and, thus, the succeeding process 26 will be significantly under capacity if the pending lots are dispatched immediately. Accordingly, a larger waiting time is allowed when a large number of expected lots will be included in this batch run to get closer to the maximum capacity of the succeeding process 26. Conversely, if a low value of k is calculated, then a large number of lots are already pending. Thus, only a small waiting time is allowed to get the few additional lots to get closer to the fall capacity of the succeeded process 26.
Following simulation shows that this LWR provides higher throughput of lots compared to using a conventional method to dispatch lots. In this simulation, assume that process L i is the ith step of a IC process flow, and this step needs long process time with batch run. In addition, the process L i has only one kind of recipe, and
average process time (T) of the process L i are 8 hours,
maximum batch size (B) of the process L i are 6 lots,
average number of lots (a) per batch processed at the process L i are 5 lots, and
number (n) of waiting WIP ready for running in the process L i at time t are 2 lots.
In the first case, an Always Run First (ARF) is used, in which any lot waiting in front of the process L i is processed. Assume that the number of lots (k) before the process L i are 3 lots, which will arrive at the process L i after 3 hours (tm) have elapsed. The ARF will recommend to process 2 lots immediately. However, the LWR will suggest to process total 5 lots (i.e., n+k=2+3) three (3) hours later because three (3) hours are less than 4.8 hours (i.e., 3/5*8) as determined in the step 34. The loss of productivity from the ARF is estimated to be 1.125 lots (i.e., 3--3*5/8).
In the second case, an Always Wait Lots (AWL) is used, in which wafers are waited until there is no more wafer arrived in the near future. Assume that the number of lots (k) before the process L i are 3 lots, which will arrive at the process L i after 6 hours (t m ). The AWL will recommend to process total 5 lots after six (6) hours have elapsed. On the contrary, the LWR will process two (2) lots immediately because 6 hours are larger than 4.8 hours (i.e., 3/5*8) as determined in the step 34. The loss of productivity from the AWL is estimated to be 0.75 lots (i.e., 6*5/8-3).
Alternatively, those skilled in the art of dispatching systems can implement other embodiments for use with a computer integrated system (CIM) without undue experimentation in light of the disclosure. In a CIM embodiment, the controller 20 can automatically and dynamically dispatch lots according to the LWR with minimal help from human operators.
In another embodiment, the LWR can be modified to account for priority of the pending and expected lots. In this embodiment, weights corresponding to the priority of the lots are assigned to the pending (i.e., w n ) and expected lots (i.e., w k ). In this embodiment, a step 35 is performed after the step 32 in which ratio of the expected to pending weights is multiplied with the expression of the step 34. The resulting maximum allowable waiting time of the modified LWR becomes (w k /w n )(k/a)T.
In yet another embodiment of the present invention, the LWR is applied to a more complex processing flow having several different processes and recipes. For example, the process flow may have the succeeding process tools X, Y, and Z. Further, each of these tools has more than one recipe with a different corresponding average process time. Table 2 below summarizes the different processes of this example, with expressions for calculating the maximum allowable waiting time for each recipe.
TABLE 2__________________________________________________________________________ maximum allowable waiting time Tmax.sub.k processtool process recipe time k = 1 k = 2 k = 3 k = 4 k = 5 k = 6__________________________________________________________________________X anneal A T.sub.A T.sub.A /ax 2T.sub.A /ax 3T.sub.A /ax 4T.sub.A /ax 5T.sub.A /ax T.sub.A B T.sub.B T.sub.B /ax 2T.sub.B /ax 3T.sub.B /ax 4T.sub.B /ax 5T.sub.B /ax T.sub.BY gate C T.sub.C T.sub.C /ay 2T.sub.C /ay 3T.sub.C /ay 4T.sub.C /ay 5T.sub.C /ay T.sub.C oxide D T.sub.D T.sub.D /ay 2T.sub.D /ay 3T.sub.D /ay 4T.sub.D /ay 5T.sub.D /ay T.sub.DZ well E T.sub.E T.sub.E /az 2T.sub.E /az 3T.sub.E /az 4T.sub.E /az 5T.sub.E /az T.sub.E drive F T.sub.F T.sub.F /az 2T.sub.F /az 3T.sub.F /az 4T.sub.F /az 5T.sub.F /az T.sub.F__________________________________________________________________________
More specifically, in Table 2: tool X is used in an anneal process having two different recipes A and B; tool Y is used in a gate oxide forming process having two different recipes C and D; and tool Z is used in a well driving process having two different recipes E and F. The fourth column lists the corresponding average process time for each recipe. The fifth through tenth columns list the maximum allowable waiting time for each value of the allowable lots k, assuming that the maximum number of latch per batch B is equal to six for each tool. The terms ax, ay and az are the average lots per batch for processes X, Y and Z, respectively. The controller 20 may have a look-up table corresponding to the data stored in the Table 2, and as a tool becomes available, the controller 20 calculates the allowable number of additional lots for the tool, and retrieves the maximum allowable wait time for the particular recipe being used by the too. Then the controller 20 compares the definite period t m of the next expected lots for this recipe of the tool to the retrieved maximum allowable wait time and uses the LWR to determine whether to dispatch the pending lots or else wait for the next expected lots.
Although specific embodiments including the preferred embodiment have been illustrated and described, it will be appreciated by those skilled in the art of dispatching systems that various modifications may be made without departing from the spirit and scope of the present invention, which is intended to be limited solely by the appended claims. For example, the number of the tools and the number of the recipes in each tool are not limited to those illustrated in the described embodiments. Moreover, the LWR disclosed in this application is not limited to the manufacture of semiconductor devices; rather, the LWR can be applied to other factory environments that have tools that require batch run and/or long process time. | A lot dispatching method and apparatus for dispatching WIP lots in the manufacture of semiconductor integrated circuits includes determining an average process time (T) and average number of lots per batch (a) of a succeeding process, and determining allowable lots (k) of a preceding process. The allowable lots (k) is equal to the preceding lots (m) undergoing the preceding process to the extent that the sum of (m) and the lots waiting to undergo the succeeding process (n) is not greater than the maximum batch size of the succeeding process. An allowable waiting time is then determined in accordance with a lot waiting rule, where the allowable waiting time represents the average time for processing the number of additional lots to be gained by waiting for the preceding process to complete. The allowable waiting time is determined by the equation k(T/a). If the expected waiting time for the preceding process to complete is greater than the determined allowable waiting time, the WIP lots (n) are immediately processed in the succeeding process; otherwise, the (n) WIP lots are not dispatched until the allowable lots (k) of the preceding process arrive, which are then combined into a single batch and dispatched into the succeeding process. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to bathtub overflow drains and is particularly related to inserts for originally installed bathtub drains.
BRIEF SUMMARY OF THE INVENTION
In the installation of bathtubs it is common that an overflow opening of the bathtub be connected to a drainpipe having a standing portion also connected to the bathtub drain and discharging downwardly to a sewer connection. A portion at the upper end of the drainpipe is angled to connect to the overflow opening. After installation it is not unusual for a gasket, positioned between the angled upper end of the drainpipe and the bathtub wall surrounding the overflow opening, to leak. This may be due to improper installation of the gasket or may be because of hardening and/or deterioration of the gasket with the passage of time. In any event, leakage past the gasket can be damaging to bathtub support structure and may run down the outer face of the bathtub. The water on the bathtub then causes the tub to rust, often without knowledge of a user of the tub until an entire section of the tub wall disintegrates and it becomes necessary to replace the entire tub.
It is also common to provide a bathtub lining of plastic material that will cover worn and damaged visible surface areas of a bathtub; Such liners are frequently formed in one piece to cover all exposed surfaces of the tub. If a bathtub liner is installed care must be taken to seal the overflow opening through the liner and the aligned overflow opening of the bathtub to prevent water moving between the liner and the bathtub.
Principal objects of the present invention are to provide an insert fitting for connection of the inlet face of a bathtub drain opening with a drainpipe and to provide a fitting that is easily installed and that will discharge into the existing, standing portion of the drain pipe to carry away overflow water, without requiring modification or change of pre-existing overflow drain structure.
Other objects are to provide such an insert fitting that will accommodate the use of existing tub drain stopper operating mechanisms and that will effectively prevent seepage of overflow water flow between a tub liner and the wall of a bathtub in which a liner is installed.
Principal features of the invention include a throat that will mount to either a bathtub wall or a bathtub liner wall and that will extend through the overflow opening and an angled discharge pipe section, into the standing portion of the drainpipe, so that overflow water entering the throat from the bathtub is discharged from the throat into the standing portion of the drain pipe.
Still another feature of the invention is a flexible throat that will accommodate use of existing operating levers and linkages to control the bathtub drain valve while carrying overflow water past the drainpipe connection to the bathtub and into the standing portion of the drainpipe.
It is yet another feature of the invention that the shape of the throat insures flow of all water from the throat either back into the bathtub or into the standing portion of the drainpipe.
Other objects and features of the invention will become apparent to those skilled in the art to which the invention pertains from the following detailed description and drawings, disclosing what is presently contemplated as being the best mode of the invention.
DRAWINGS
In the drawings:
FIG. 1 is a sectional view taken through a portion of a bathtub liner, a bathtub wall and centrally through the throat of the invention;
FIG. 2, a sectional view taken on the line 2 — 2 of FIG. 1;
FIG. 3, a front elevation view of a retaining plate for securing the throat of the invention and an overflow cover plate to a bathtub liner or a bathtub wall;
FIG. 4, a view like that of FIG. 1, but showing an alternate retaining plate suitable for use with a bathtub drain plug operating mechanism;
FIG. 5, a front elevation view of the alternative retainer plate of FIG. 4; and
FIG. 6, a front elevation of a seal positioned between a flange of the throat and the bathtub liner or bathtub wall.
DETAILED DESCRIPTION
Referring now to the drawings:
In the illustrated preferred embodiment of the invention, a throat 10 is shown secured to a bathtub liner 12 and extending through the liner and a bathtub wall 14 and into a drainpipe 16 . Drainpipe 16 includes an angled end portion 18 , with an end flange 20 shown connected to the bathtub wall 14 . The angled end portion 18 is shown forming a right angle connection with a standing portion 24 of the drainpipe 16 , although it should be apparent that a connection other than a right angle connection may be provided between the angled end portion 18 and standing portion 24 and, in fact, in some instances the connections are curved or differently angled. A seal 26 is provided between end flange 20 and the bathtub wall 14 . Seal 26 is the seal that often allows leakage of the water from the bathtub.
Throat 10 has a flange 28 surrounding and extending outwardly from an inlet end 30 , a central wall portion 32 tapered from the flange 28 towards a flared wall portion 34 , that terminates in a discharge end 36 . Preferably, throat 10 is formed of a long lasting rubber, such as silicone rubber, or another rubber or plastic material that will be flexible, while generally maintaining its formed shape and capable of withstanding the corrosive effect of water, soap and other chemicals passed through the throat during use. Water in the throat 10 will either flow along tapered wall portion 32 back into the bathtub or through the flared wall portion 34 into the drainpipe 24 . When made to be somewhat flexible, the throat can be bent during installation to allow it to fit into a drainpipe having an angled end portion other than the right angle configuration shown.
The length of throat 10 , between flange 28 and the discharge end 36 , is such that when flange 28 is positioned against the inner surface of liner 12 , or if no liner is provided the inner surface 38 of bathtub wall 12 . The central wall portion 32 and flared wall portion 34 of throat 10 extend through the angled end portion 18 such that the discharge end 36 terminates within the standing portion 24 of drainpipe 16 .
As shown best in FIGS. 1-3, flange 28 of throat 10 is bonded to the face of bathtub liner 12 , or, if no liner is provided, with the inner surface 38 of the bathtub wall 14 with a bead of adhesive 40 . The flange 28 is further secured to the tub liner or bathtub with screws 42 inserted through holes 44 in the retainer plate 46 , holes in flange 28 of the throat 10 , aligned holes through the seal 26 and screwed into the threaded holes 50 of flange 20 . A screw 52 through a cover plate 54 is screwed into a threaded hole 62 in a bar 64 that extends across the central opening 66 of retainer plate 46 secures the cover plate to the liner or bathtub wall.
A seal 58 , FIG. 6 may be inserted between flange 28 of throat 10 and the liner (or bathtub) in place of the bead of adhesive 40 , if desired
As best seen in FIG. 4, the flexible throat 10 bends to accommodate use of a lever 70 , and linkage arms 72 and 74 used to operate a drain valve 76 within the standup portion 24 of drainpipe 16 . Such actuating mechanisms are well known, and generally extend through and are pivoted on a cover plate. In this embodiment a retainer plate 82 is used to secure the flange 28 of throat 10 in place. Screws inserted through holes in the cover plate and through the holes 84 of retainer plate 82 , FIG. 5, hold the retainer plate 82 in place.
Although a preferred form of my invention has been herein disclosed, it is to be understood that the present disclosure is by way of example and that variations are possible without departing from the subject matter coming within the scope of the following claims, which subject matter I regard as my invention. | A method and apparatus for modifying a bathtub overflow drain to bypass potential leakage zones, i.e. between a bathtub liner and between connections of fittings through inserting a throat member from the innermost surface of the bathtub, which may be the innermost surface of a bathtub liner, to the interior of the standing portion of a drainpipe. | 4 |
TECHNICAL FIELD OF THE INVENTION
[0001] The disclosure relates to the technical field of weaving shaping of composite materials, and more particularly to a multi-dimensional weaving shaping machine of composite materials.
BACKGROUND OF THE INVENTION
[0002] As part of strategic emerging industries in China, high-strength fibers including carbon fibers, aramid fibers, polyethylene and fiberglass and the composite material products thereof have the advantages of light weight, high strength, corrosion resistance and unique concealment performance etc. Composite materials, which are widely applied in fields including wind energy, aeronautics and astronautics, automobiles, railway communication, buildings, weapons, armors, ships, chemical engineering and sports etc., have been an important fiercely-competitive industry that is developed by countries all over the world as a priority. Composite materials are basic key materials in sophisticated industries including aeronautics and astronautics etc. For example, composite material technology are the most critical technology in the competition between Boeing and Airbus as well as one of the major bottlenecks of civil aircraft projects in China. The composite materials used in Boeing 787 already account for more than 50% of the total mass of the plane. Shells of stealth fighters are basically made of microwave absorbing composite materials. In the meanwhile, composite materials are one of the basic factors for stealth of planes and naval vessels. Although having many excellent performances, the following disadvantages need to be overcome to expand the application of composite materials:
[0003] 1. Easy Interlaminar Cracking
[0004] Most existing fiber composite materials are produced by superimposing fiber sheets including fiber cloth and prepregs etc. to a certain thickness and cure the fiber sheets by resin substrates. Thanks to the ultra-high strength fibers on the surfaces in 2 dimensions of the sheets, strength of the sheets are several times stronger than that of steel and may reach above 3000 MPa. However, there are resin plastic substrates among the sheets, and the interlaminar strength are extremely low at just 100 MPa. The difference between the fiber strength in the layers and the plastic strength among the layers is as much as more than 30 times. Therefore, easy interlaminar cracking is an intrinsic disadvantage of fiber composite materials. Because of the weak interlaminar strength, as well as the relatively low impact strength and compressive strength, interlaminar cracking is the main failure of composite materials, especially when impacted and compressed to cause fatigue.
[0005] Methods including interlaminar stitching, three-dimensional spinning and three-dimensional weaving etc. may be applied in order to improve the interlaminar strength of composite materials. Although some achievements have been made in the research and development, these technologies have complicated processes together with very high cost and limited use. Nevertheless, broadly-applied multi-axial warp knitted composite materials fail to obtain three-dimensional structures due to the thickness limitation. So, interlaminar cracking is the major disadvantage that harasses the performance of composite materials. Therefore, it's been a problem in the world to enhance the interlaminar strength of composite materials at low costs.
[0006] 2. Low Lamination Efficiency and High Labor Costs
[0007] Usually, if long staples are required to be used as structural materials, fiber sheets are manufactured by yarns and composite material plates or products are produced by superimposing layers of fiber sheets to a certain thickness. Processes of production of yarns, fabrics, plies/composites are necessary in the application of long staples as materials. However, only the process of fabricating yarns into fabrics can be realized efficiently by spinning techniques in the whole production process of fiber composite material products. Since fiber sheets can be hardly operated automatically and mechanically, expensive automatic fiber orientation devices can be applied only in sophisticated industries that require very high lamination accuracy of fiber sheets, such as aircraft manufacturing. Therefore, fiber sheets are mostly laminated into plates and products manually in the industry of composite materials, which is low in production efficiency and high in labor cost, wherein the low manual lamination efficiency has always been the main bottleneck of the production process of composite materials.
[0008] 3. Expensive High-Strength Fibers Including Carbon Fibers, Aramid Fibers and High-Modulus Polyethylene Etc.
[0009] The low interlaminar strength, the low lamination efficiency and the high labor costs of lamination processes of fiber composite materials result in limited application of composite materials and limited demands of high-strength fibers including carbon fibers, aramid fibers and high-modulus polyethylene etc. that are mainly used in high-end products in the market. Along with the technical monopoly of developed countries on carbon fibers, aramid fibers and high-modulus polyethylene, these high-strength fibers are naturally very expensive. The good news is that production problems of carbon fibers and high-modulus polyethylene have been solved in China in recent years to realize localization, and aramid fibers will be produced at home soon.
[0010] If the interlaminar strength of composite materials are improved and composite materials can be laminated automatically at low costs, the application demands of composite materials will increase inevitably, the yields of carbon fibers, aramid fibers and high-modulus polyethylene will be also increased greatly and their manufacturing costs are expected to decrease.
SUMMARY OF THE INVENTION
[0011] The objective of the disclosure is to provide a multi-dimensional weaving shaping machine of composite materials to solve the technical problem of the lack of highly-automatic manufacturing devices capable of fabricating high-strength composite materials in the prior art.
[0012] To realize the objective above, the disclosure provides a multi-dimensional weaving shaping machine of composite materials, including: a guide template including a plurality of cylindrical guiders arranged according to the geometrical shape of a prefabricated member; an electrical control three-dimensional motion mechanism located above the guide template, and including: a control signal receiving terminal configured to receive motion control signals corresponding to the geometrical shape of the prefabricated member; and a three-dimensional motion output terminal configured to form a motion track according to the motion control signal; a weaving mechanism including: a weaving needle being connected with the three-dimensional motion output terminal for driving weave fibers to move among the cylindrical guiders along the motion track so that the weave fibers are distributed among the cylindrical guiders according to the geometrical shape of the prefabricated member.
[0013] Further, the guide template includes a weaving plate, on which a plurality of uniformly-distributed first through holes are provided; a perforated plate is set below the weaving plate; a plurality of guide columns of which the heights are adjustable heights are set below the perforated plate; the perforated plate is provided with a plurality of second through holes coaxially corresponding to the first through holes; the guide columns pass through the first through holes and the second through holes; the cylindrical guiders are cylindrical sleeves which are sleeved on the guide columns and provided with optional heights.
[0014] Further, a pneumatic chuck for clamping the weaving needle, the cylindrical guiders and/or the guide columns is set on the three-dimensional motion output terminal.
[0015] Further, each of the guide columns is provided with clamping grooves distributed axially at equal intervals. A moveable adjusting plate is set below the perforated plate. A guide column support plate that is static relative to the perforated plate is set below the moveable adjusting plate. The moveable adjusting plate is capable of sliding relative to the perforated plate. A plurality of elongated and round apertures opposite to the second through holes of the perforated plate are set on the moveable adjusting plate. The guide columns pass through the elongated and round apertures and move in the elongated and round apertures with the movement of the moveable adjusting plate.
[0016] Further, locking members matched with the clamping grooves are set on the moveable adjusting plate. The moveable adjusting plate has a locking position to match the locking members with the clamping grooves so as to lock the heights of the guide columns and an unlocking position to separate the locking members and the clamping grooves.
[0017] Further, the locking member is a leaf spring set at an end of the extension direction of the elongated and round aperture and obliquely extending to the guide column located in the elongated and round aperture. The clamping grooves are formed by the conical portions of the guide column and flanges set on the small-diameter ends of the conical portions.
[0018] Further, a first support framework is set below the moveable adjusting plate. The first support frame is provided with a first support frame located on the periphery of the moveable adjusting plate. A locating plate is set on the first support frame. The side face of the locating plate is provided with an adjusting screw rod extending horizontally. The first end of the adjusting screw rod is fixedly connected with the moveable adjusting plate.
[0019] Further, the bottom surface of the moveable adjusting plate is provided with a shifting yoke. The first end of the adjusting screw rod is fixedly connected with the moveable adjusting plate through the shifting yoke, and the second end of the adjusting screw rod is provided with an adjusting handle.
[0020] Further, a connecting hole configured to connect the first support frame is further set on the locating plate.
[0021] Further, the first support framework includes four first support legs, and the guide column support plate is located between the four first support legs.
[0022] Further, a plurality of locating sleeves coaxially matched with the second through holes are further provided on the perforated plate, and the guide columns pass through the locating sleeves.
[0023] Further, the upper end of the guide column is provided with first annular platform extending outwards along the radial direction.
[0024] Further, the periphery of the cylindrical guider is provided with a plurality of layers of ring grooves for limiting the positions of the weave fibers.
[0025] Further, the upper end of the cylindrical guider is provided with a second annular platform extending outwards along the radial direction.
[0026] Further, the electrical control three-dimensional motion mechanism further includes: an X axis motion unit including an X supporter extending along a first direction; an X axis guide rail set on the X axis supporter; an X axis synchronous belt motion mechanism set along the X axis guide rail and provided with an X axis slider; a Y axis motion unit including: a Y axis supporter connected with the X axis slider and extending along a second direction vertical to the first direction; a Y axis guide rail set on the Y axis supporter; a Y axis synchronous belt motion mechanism set along the Y axis guide rail and provided with a Y axis slider; a Z axis motion unit including: a Z axis supporter extending along a third direction vertical to the plane formed by the first direction and the second direction; a Z axis guide rail set on the Z axis supporter; a Z axis synchronous belt motion mechanism set along the Z axis guide rail and provided with a Z axis slider; the Z axis slider is fixedly connected with the Y axis slider, wherein a three-dimensional motion output terminal is formed at the lower end of the Z axis supporter.
[0027] Further, the X axis supporter includes a first supporter and a second supporter in parallel. The X axis guide rail includes a first guide rail and a second guide rail set on the first supporter and the second supporter, respectively. The X axis synchronous belt motion mechanism is set on the first supporter. The synchronous belt of the X axis synchronous belt motion mechanism is connected with the first end of the Y axis supporter. The X axis slider includes a first slider located on the first guide rail and a second slider located on the second guide trail. The first slider and the second slider are located below the first end and the second end of the Y axis supporter, respectively.
[0028] Further, the multi-dimensional weaving shaping machine of composite materials in the disclosure further includes a cylindrical guider storage shelf located at the first side of the guide template. The cylindrical guider storage shelf includes a guider storage support bracket and a storage plate set on the guider storage support bracket. A plurality of cylindrical guiders with different heights are pre-stored on the storage plate.
[0029] Further, a plurality of uniformly-distributed threaded holes are provided on the storage plate. Storage support rods for supporting the cylindrical guiders are provided in the threaded holes. The lower ends of the storage support rods are provided with external threads matched with the threaded holes.
[0030] Further, the weaving mechanism further includes a fiber yarn feeding and tensioning mechanism located at the second side of the guide template.
[0031] Further, the fiber yarn feeding and tensioning mechanism includes: a third bracket; a fiber roll installation bracket set on a support beam of the third bracket and provided with support rods for supporting fiber rolls; tension pulley base plates set on the support beam of the third bracket. A tension pulley for providing fiber yarns to the weaving needle and a guide pulley are provided on each of the tension pulley base plate.
[0032] Further, the fiber yarn feeding and tensioning mechanism further comprises a weaving needle base for storing the weaving needle and the weaving needle base is located on one side of the tension pulley base plate.
[0033] The Disclosure has the Following Beneficial Effect:
[0034] The multi-dimensional weaving shaping machine of composite materials of the disclosure utilizes the cylindrical guiders and the electrical control three-dimensional motion mechanism to make the weaving needle to drive braided cords to distribute among the cylindrical guiders along the motion track to form the guide template. The machine is applicable to multi-dimensional weaving shaping of large-scale and complicated materials and capable of improving the interlaminar strength of composite materials. The shaping machine applies a rapid shaping technology to multi-dimensional weaving shaping of composite materials and the technical processes are automatic.
[0035] Besides the objectives, characteristics and advantages described above, the disclosure has other objectives, characteristics and advantages. The disclosure will be described in details below with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The accompanying drawings that constitute a part of the application are used for providing further understanding to the disclosure. The exemplary embodiments of the disclosure and the illustrations thereof are used for explaining the disclosure, instead of constituting an improper limitation to the disclosure. In the accompanying drawings:
[0037] FIG. 1 is a schematic diagram illustrating a stereo structure of a multi-dimensional weaving shaping machine of composite materials in a preferred embodiment of the disclosure;
[0038] FIG. 2 is a schematic diagram illustrating a composition structure of a guide template in a preferred embodiment of the disclosure;
[0039] FIG. 3 is a structural diagram illustrating a guider support rod in a preferred embodiment of the disclosure;
[0040] FIG. 4 is a schematic diagram illustrating a surface structure of a cylindrical guider in a preferred embodiment of the disclosure;
[0041] FIG. 5 is a schematic diagram illustrating an adjusting structure of a moveable adjusting plate below a guide template in a preferred embodiment of the disclosure;
[0042] FIG. 6 is a schematic diagram illustrating a position relation between a locking member and a clamping groove during free falling of a guider support rod after weaving;
[0043] FIG. 7 is a schematic diagram illustrating a position relation between a locking member and a clamping groove when a moveable adjusting plate is located in a locking position;
[0044] FIG. 8 is a structural diagram of an electrical control three-dimensional motion mechanism in a preferred embodiment of the disclosure;
[0045] FIG. 9 is a schematic diagram illustrating an enlarged structure of Part II in FIG. 8 ;
[0046] FIG. 10 is a structural diagram of an X axis motion unit in an embodiment of the disclosure;
[0047] FIG. 11 is a structural diagram illustrating partial enlargement in an A direction in FIG. 10 ;
[0048] FIG. 12 is a structural diagram of a Y axis motion unit in a preferred embodiment of the disclosure;
[0049] FIG. 13 is a structural diagram in a B direction in FIG. 12 ;
[0050] FIG. 14 is a structural diagram illustrating partial enlargement of 30 a in FIG. 8 ; and
[0051] FIG. 15 is a schematic diagram illustrating partial enlargement of a fiber yarn feeding and tensioning mechanism in a preferred embodiment of the disclosure.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0052] The embodiments of the disclosure will be described below in combination with the accompanying drawings. However, the disclosure can be implemented by many different methods limited and covered by the claims.
[0053] As shown in FIG. 1 , the disclosure provides a multi-dimensional weaving shaping machine of composite materials, including: a guide template 60 , wherein the guide template 60 includes a plurality of cylindrical guiders 62 arranged according to the geometrical shape of prefabricated member; an electrical control three-dimensional motion mechanism 30 located above the guide template 60 , wherein the electrical control three-dimensional motion mechanism 30 includes: a control signal receiving terminal configured to receive motion control signals; a three-dimensional motion output terminal 30 a configured to form a motion track according to the motion control signals. The multi-dimensional weaving shaping machine of composite materials of the disclosure further includes: a weaving mechanism 50 . The weaving mechanism 50 includes: a weaving needle 14 connected with the three-dimensional motion output terminal 30 a and driving weave fibers to distribute among the cylindrical guiders 62 along the motion track.
[0054] As shown in FIG. 2 , in order to shape the guide template 60 , the guide template 60 includes a weaving plate 60 a . A plurality of uniformly-distributed first through holes are provided on the weaving plate 60 a . The weaving plate 60 a is supported by a rectangular frame 59 . A perforated plate 65 is set below the weaving plate 60 a . The weaving plate 60 a is provided with a plurality of second through holes coaxially corresponding to the first through holes. A plurality of guide columns 61 with adjustable heights are set below the perforated plate 65 . The upper ends of the guide columns 61 pass through the first through holes and the second through holes to locate above the weaving plate 60 a . The cylindrical guiders 62 are cylindrical sleeves which are sleeved on the guide columns 61 and provided with optional heights.
[0055] As shown in FIG. 3 , a guide column 61 is provided with clamping grooves 61 a distributed axially at equal intervals. The clamping grooves 61 a may be formed by the conical portions of the guide column 61 and flanges set on the small-diameter ends of the conical portions. The upper end of the guide column 61 are provided with a first annular platform 61 c extending outwards along the radial direction. The portion below the first annular platform 61 c may be grabbed by a clamping device to move the guide column 61 .
[0056] As shown in FIG. 4 , in order to locate the weave fibers to the surfaces of a cylindrical guider 62 , the peripheries of the cylindrical guider 62 are provided with a plurality of layers of ring grooves 62 a for limiting the positions of the weave fibers. Each ring groove 62 a is formed by a plurality of flanges extending outwards along the radial direction on the cylindrical guider 62 . In order to grab the cylindrical guider 62 conveniently, the upper end of the cylindrical guider 62 may be provided with a second annular platform 62 c extending outwards along the radial direction, and the portion below the second annular platform 62 c may be clamped by a chuck to clamp the cylindrical guider 62 .
[0057] As shown in FIG. 5 , a moveable adjusting plate 68 is set below the perforated plate 65 . A guide column support plate 64 that is static relative to the perforated plate 65 is set below the moveable adjusting plate 68 . When all the guide columns 61 fall (see FIG. 2 ), the lower ends of the guide columns 61 are located on the guide column support plate 64 . The moveable adjusting plate 68 is sliding relative to the perforated plate 65 . A plurality of elongated and round apertures 72 (see FIG. 6 ) opposite to the through holes of the perforated plate 65 are set on the moveable adjusting plate 68 . The guide columns 61 pass through the elongated and round apertures 72 and move in the elongated and round apertures 72 with the movement of the moveable adjusting plate 68 .
[0058] locking members matched with the clamping grooves 61 a are set on the moveable adjusting plate 68 . The moveable adjusting plate 68 is provided with alocking position to match the locking members with the clamping grooves 61 a so as to lock the heights of the guide columns 61 and an unlocking position to separate the locking members and the clamping grooves 61 a so as to continue to adjust the heights of the guide columns 61 .
[0059] A first support framework 58 (see FIG. 2 ) is set below the moveable adjusting plate 68 . The first support frame 58 is provided with a first support frame 58 a located on the periphery of the moveable adjusting plate 68 . See FIG. 5 , a locating plate 63 is set on the first support frame 58 a . Internal threaded holes are set on the locating plate 63 . Adjusting screw rod 69 matched with one of the internal threaded holes are provided in the internal threaded hole. The telescopic end of the adjusting screw rod 69 are fixedly connected with the moveable adjusting plate 65 .
[0060] As shown in FIG. 6 and FIG. 7 , the locking member may be a leaf spring 71 set at an end of the extension direction of the elongated and round aperture 72 and obliquely extending to the guide column 61 located in the elongated and round aperture 72 .
[0061] See FIG. 5 , the bottom surface of the moveable adjusting plate 68 is fixed with a shifting yoke 70 . The first end of the adjusting screw rod 69 are fixedly connected with the shifting yoke 70 and the second end of the adjusting screw rod 69 are provided with adjusting handle 69 a . The adjusting screw rod 69 are rotated by using the adjusting handle 69 a , and the adjusting screw rod 69 stretch in the internal threaded hole of the locating plate 63 to drive the shifting yoke 70 to move to further drive the moveable adjusting plate 68 to move so that the leaf springs 71 is matched with the clamping grooves 61 a to lock the guide columns 61 . For the time being, the guide columns 61 can be only elevated and cannot be lowered. After weaving a component, the relative linear motion of the adjusting screw rod 69 and the locating plate 63 drives the moveable adjusting plate 68 to move in a straight line so that the guide columns 61 can fall freely onto the guide column support plate 64 instead of being clamped tightly by the leaf springs 71 .
[0062] A plurality of connecting holes 63 a configured to connect the first support frame 58 a is further set on the locating plate 63 .
[0063] See FIG. 2 , the first support framework 58 includes four first support legs 58 c , and the guide column support plate 64 is located between the four first support legs 58 c.
[0064] A plurality of locating sleeves 66 (see FIG. 2 and FIG. 5 ) coaxially matched with the second through holes are further provided on the perforated plate 65 , and the guide columns 61 pass through the locating sleeves 66 .
[0065] The layout size or shape of the cylindrical guiders 62 in the guide template 60 may be changed according to the external feature of a pre-woven component. The heights of the guide columns 61 for supporting the cylindrical guiders 62 can be adjusted according to the external feature of the pre-woven component. The perforated plate 65 is fixed on the first support framework 58 . locating sleeves 66 sleeved on the periphery of the guide columns 61 are installed on the perforated plate 65 to improve the rigidity of the guide columns 61 . The moveable adjusting plate 68 is suspended below the perforated plate 65 by a plurality of perforated plate mounting bases 67 (see FIG. 5 ) fixed with the perforated plate 65 , and may make a linear motion relative to the perforated plate 65 . The leaf springs 71 are matched with the elongated and round apertures 72 on the moveable adjusting plate 68 to clamp or release the guide columns 61 .
[0066] The cylindrical guiders 62 with different heights can be stored on a cylindrical guider storage plate 83 (see FIG. 1 ). The cylindrical guiders 62 with different heights are selected and sleeved on the matrix of the guide columns 62 according to the external features of the woven component to perform approximate weaving.
[0067] As shown in FIG. 8 , the electrical control three-dimensional motion mechanism 30 further includes: an X axis motion unit including an X supporter extending along a first direction and an X axis guide rail set on the X axis supporter and an X axis synchronous belt motion mechanism set along the X axis guide rail and provided an X axis slider; a Y axis motion unit including a Y axis supporter 12 connected with the X axis slider and extending along a second direction vertical to the first direction and a Y axis guide rail 11 set on the Y axis supporter 12 and a Y axis synchronous belt motion mechanism set along the Y axis guide rail 11 and provided with a Y axis slider 31 ; a Z axis motion unit including a Z axis supporter 8 extending along a third direction vertical to the plane formed by the first direction and the second direction and a Z axis guide rail 9 set on the Z axis supporter 8 and a Z axis synchronous belt motion mechanism set along the Z axis guide rail 9 and provided with a Z axis slider 33 which is fixedly connected with the Y axis slider 31 , wherein a three-dimensional motion output terminal 30 a is formed at the lower end of the Z axis supporter 8 .
[0068] In order to improve the support strength of the electrical control three-dimensional motion unit, the X axis supporter may include a first supporter 3 and a second supporter 6 in parallel. The X axis guide rail includes a first guide rail 5 and a second guide rail 7 set on the first supporter 3 and the second supporter 6 , respectively. A first synchronous belt motion mechanism and a second synchronous belt motion mechanism are set on the first guide rail 5 and the second guide rail 7 , respectively. The first synchronous belt motion mechanism and the second synchronous belt motion mechanism are provided with a first slider 17 (see FIG. 11 ) and a second slider 27 (see FIG. 9 ), respectively. The two ends of the Y axis supporter 12 are connected with the first slider 17 and the second slider 27 , respectively.
[0069] Actually, motion units that are more multi-dimensional, including a four-axis motion unit or a five-axis motion unit etc. can be also applied so as to realize multi-dimensional weaving of composite materials.
[0070] More specifically, the X axis motion system includes the first guide rail 5 and the second guide rail 7 in parallel. The first guide rail is supported by the first supporter 3 and the second guide rail 7 is supported by the second supporter 6 . There is a predetermined distance between the first supporter 3 and the second supporter 6 . The distance between the first supporter 3 and the second supporter 6 can be determined by the width of the guide template 60 (see FIG. 1 ). The distance between the first supporter 3 and the second supporter 6 may be set relatively long and the size of the guide template 60 is increased correspondingly to adapt to the space required to weave a large component. The first slider 17 is set on the first guide rail 5 . The second slider 27 is set on the second guide rail 7 . The first supporter 3 and the second supporter 6 are connected by a transverse connecting rod 13 (see FIG. 8 ). One end of the Y axis supporter 12 can be connected with the first slider 17 by an XY connecting plate 18 (see FIG. 11 ). The X axis synchronous belt 21 in the X axis synchronous belt mechanism is connected to the other end of the Y axis supporter 12 by an X axis synchronous belt fixing plate 26 .
[0071] As shown in FIG. 10 , an X axis driving synchronous belt wheel 22 is connected with an X axis decelerator 24 fixed on the first supporter 3 by a rolling bearing. An X driven synchronous belt wheel 19 is installed on an X axis driven wheel spindle 50 by a bearing and a retainer ring at the end of the bearing. The X axis driven wheel spindle 50 is tightened on the first supporter 3 by threads. The X axis motion unit takes an X axis motor 25 and the X axis decelerator 24 as the power units drives the X axis driving synchronous belt wheel 22 to function as a drive unit by the X axis motor 25 so as to drive the first slider 17 and the second slider 27 to move on the first guide rail 5 and the second guide rail 7 .
[0072] As shown in FIG. 12 , the Z axis motion unit includes the Z axis guide rail 9 . The Z axis guide rail 9 is supported by the Z axis supporter 8 . The Z axis slider 33 is set on the Z axis guide rail 9 . The Z axis slider 33 is connected with the Y axis slider 31 by a YZ orthogonal connecting plate 10 . A Y axis synchronous belt joint pressing plate 38 in the Y axis synchronous belt mechanism presses the Y axis synchronous belt 32 on a Y axis synchronous belt fixing plate 39 and is fixed on the YZ orthogonal connecting plate 10 . A Y axis driving synchronous belt wheel 35 is connected with a Y axis decelerator 36 on the Y axis supporter 12 by a rolling bearing. A Y axis driven synchronous belt wheel 29 is installed on a Y axis driven wheel spindle 49 by a bearing and a retainer ring at the end of the bearing. The Y axis driven wheel spindle 49 is secured on the Y axis supporter 12 (see FIG. 9 ). The Y axis motion system takes a Y motor 37 and the Y axis decelerator 36 as the power units, and takes the Y axis motor 37 and the Y axis driving synchronous belt wheel 35 as the drive units so as to drive the Y axis slider 31 to move on the Y axis guide rail 11 .
[0073] As shown in FIG. 13 , a Z axis driving synchronous belt wheel base 42 is fixed on the orthogonal connecting plate 10 . A Z axis driving synchronous belt wheel 47 is connected with a Z axis decelerator 40 fixed on the Z axis driving synchronous belt wheel base 42 by a rolling bearing. The direction of Z axis driving synchronous belt wheel 47 is changed by a synchronous belt pulley 45 . The synchronous belt pulley 45 is installed on a synchronous belt pulley shaft 48 by a bearing and a retainer ring at the end of the bearing. The synchronous belt pulley shaft 48 is secured on the Z axis driving synchronous belt wheel base 42 by threads.
[0074] See FIG. 1 , the multi-dimensional weaving shaping machine of composite materials of the disclosure further includes: a cylindrical guider storage shelf 80 located at the first side of the guide template 60 . The cylindrical guider storage shelf 80 includes a guider storage support bracket 81 and a storage plate 83 set on the guider storage support bracket 81 . A plurality of cylindrical guiders 62 with different heights are pre-stored on the storage plate 83 .
[0075] A plurality of uniformly-distributed threaded holes are provided on the storage plate 83 . Storage support rods (not shown in the figure) for supporting the cylindrical guiders 62 are provided in the threaded holes. The lower ends of the storage support rods are provided with external threads matched with the threaded holes.
[0076] As shown in FIG. 14 , a pneumatic chuck 15 for clamping the weaving needle and the cylindrical guiders 62 pre-stored on the storage plate 83 is set on the three-dimensional motion output terminal 30 a . The pneumatic chuck 15 may apply an existing standard component.
[0077] See FIG. 1 , a weaving mechanism 50 of the multi-dimensional weaving shaping machine of composite materials of the disclosure further includes a fiber yarn feeding and tensioning mechanism located at the second side of the guide template 60 .
[0078] As shown in FIG. 15 , the fiber yarn feeding and tensioning mechanism includes: a third bracket 57 ; a fiber roll installation bracket 56 set on a support beam 57 a of the third bracket 57 and provided with support rods for supporting fiber rolls 55 ; tension pulley base plates 52 set on a support beam 57 a and located on the top of the ramp of the fiber roll installation bracket 56 . A tension pulley 53 for providing fiber yarns to the weaving needle and a guide pulley 54 are provided on each of the tension pulley base plates. The fiber roll installation bracket 56 is installed on the support beam 57 a by bolts. The fiber rolls 55 are placed transversely on the fiber roll installation bracket 56 . The tension pulley base plates 52 and a weaving needle base 51 are installed on another support beam 57 a by bolts. The tension pulley 53 and the guide pulley 54 are installed on each of the tension pulley base plates 52 . After being guided by the guide pulley 54 , the fiber yarns of the fiber roll 55 are tensioned by the tension pulley 53 and carried by the weaving needle 14 (see FIG. 1 ) to be woven.
[0079] The above are only the preferred embodiments of the disclosure and not intended to limit the disclosure. For those skilled in the art, the disclosure may have various modifications and changes. Any modifications, equivalent replacements and improvements etc. made within the spirit and principle of the disclosure shall be included in the protection scope of the disclosure. | The disclosure provides a multi-dimensional weaving shaping machine of composite materials, including: a guide template including a plurality of cylindrical guiders arranged according to the geometrical shape of a prefabricated member; an electrical control three-dimensional motion mechanism including: a control signal receiving terminal configured to receive motion control signals corresponding to the geometrical shape of the prefabricated member; and a three-dimensional motion output terminal configured to form a motion track according to the motion control signals; a weaving needle being connected with the three-dimensional motion output terminal and making weave fibers distribute among the cylindrical guiders according to the geometrical shape of the prefabricated member. The multi-dimensional weaving shaping machine of composite materials of the disclosure utilizes the cylindrical guiders and the electrical control three-dimensional motion mechanism to make the weaving needle to drive braided cords to distribute among the cylindrical guiders along the motion track to form the guide template. The disclosure is applicable to multi-dimensional weaving shaping of large-scale and complicated materials and capable of improving the interlaminar strength of composite materials. The shaping machine applies a rapid shaping technology to multi-dimensional weaving shaping of composite materials and the technical processes are automatic. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to access control, and more particularly to credential-based access control in a distributed access control system.
BACKGROUND OF THE INVENTION
[0002] A computing environment may contain a variety of entities and resources. Entities may include users, operating systems, applications, processes, threads, objects, etc. Resources may include information, files, network connections, properties and methods of objects, etc. Generally, when one entity (“client”) wants to access a resource owned or administered by another entity (“server”), the client issues an access request to the server. The server may use a program that manages the resource (“resource manager”) to decide whether to grant the access request. The decision process is usually called an access control process. The resource manager may make the decision by consulting pre-configured access policies for the resource (“use policy”). The resource manager, the resource, and the associated use policy may be considered as parts of the server. The resource manager and the associated use policy constitute an access control system.
[0003] Traditional access control systems tend to be static and closed with regard to which entity can access a resource. In such access control systems, a client typically is an authenticated entity that is locally known to the server, and information needed to make a decision is usually available locally on the server. As a result, the server needs to administer the entire complexity of access control locally and cannot delegate some of the administration work to other entities.
[0004] The development of distributed and dynamic computing environments, such as the Internet, has made static and closed access control systems inadequate. For example, an entity that is not locally known to a server may request to access a resource on the server. The entity may provide information for the resource manager to use during its decision process. The information provided by an entity can be a reply to a proposition from the server that requests the entity to prove before granting the entity the requested access. Such a reply is also called a proof. The entity may supply credential statements along with the access request. The credential statements provide information to identify who the entity is. The credential statements may include more than authentication information used to help determine who the entity is. The credential statements may also include additional policy statements. Because the authenticity and integrity of policy statements can be secured with current cryptographic technologies, an owner of a resource may remotely author policy statements and provide the policy statements to a client. The client can then present the policy statements to the resource manager of the resource. The resource manager may then check the veracity of the policy statements and consult with the owner of the resource. The resource manager may eventually provide access in a manner consistent with the resource owner's intent as expressed in the policy statements.
[0005] The ability to configure policy remotely through cryptographically protected statements provides many opportunities for an access control system to depart from the traditional closed and static model. For example, a client may bring a statement authored by an entity that certifies the client to be a member of a pre-determined group. The client may also bring a statement authored by the resource owner, saying that members of the group, according to the entity, may access the resource. Together, these statements imply that the client should be able to access the resource. In such an example, the resource manager may have no prior knowledge of the entity that certifies the client to be a member of the authenticated group. The resource manager also may not know a priori that the resource owner has delegated the certifying ability to the entity only for the purpose of this specific access control decision.
[0006] Certain approaches, such as ISO Rights Expression Language (XrML 2.x) and Delegation Logic, represent statements in a logical form so that the access control decision can be computed symbolically from the statements themselves. More specifically, these approaches have their basis in predicate calculus, and their computing process on whether access should be granted according to the owner's intent is equivalent to finding a proof The proof-based approach has several advantages. The most important advantage is that it provides a mathematically verifiable reason why access ought to be granted. Another advantage is that there is no need to translate the meaning of the expression to some other form to uncover the owner's intent; reasoning can be done at the expression level itself.
[0007] To enable diverse delegation scenarios, a resource manager needs to process the statements provided by clients and decide whether or not to grant the requested access. To allow for multiple statements to imply access in a scalable and manageable fashion, a resource manager needs to reason with the underlying meaning and intent inherent in the statements supplied by a client. Such a reasoning process may be called “computing the proof” or “theorem proving.”
[0008] However, the process of theorem proving can become cumbersome. Declarative authorization systems are closely aligned with declarative programming languages, such as Prolog. Theorem proving is computationally equivalent to the imperative semantics of more common programming systems like C++, C#, or Java. As such, theorem proving can be used to encode arbitrary computation problems, i.e. arbitrary computer programs. As such, theoretical limitations exist as to how fast proofs can be computed. For example, for full predicate calculus, in the worst case, no existing algorithm can guarantee to terminate when computing proofs just as there exist questions that cannot be answered in C++, C#, etc. As a result, a decision on access control may never be reached for this class of problems. The open ending may expose a resource manager to adversary attacks. For example, a client can build bogus assertions to severely task a resource manager into computing proofs, including constructing proofs of unbounded size. The bogus assertions may also induce a resource manager to spend an unbounded amount of time and/or space in order to conclude the nonexistence of a proof. When a resource manager enters endless computation, the resource manager has to deny services to other entities. Such situations are called denial of service attacks, which can interrupt network routing services and render networks inoperable.
[0009] Therefore, there exists a need to relieve a resource manager's onerous computing of proofs so as to avoid the negative consequences, such as denial of service attacks, brought by endless computing.
SUMMARY OF THE INVENTION
[0010] The invention addresses the above-identified need by providing supporting statements, i.e., additional assertions that help to construct a proof for safe and efficient verification. The additional assertions enable a resource manager to examine and verify a proof instead of computing a proof.
[0011] One aspect of the invention provides a system comprising a server component, a client component, and one or more supporting statements, i.e., additional assertions. The server component is any entity that owns or administers a resource. The resource is associated with a use policy that dictates who can access the resource. The client component is any entity that requests to access the resource. The system may be supplemented by one or more entities (“auxiliary clients”). The client component and/or the auxiliary clients supply information such as credential statements and/or additional assertions to the server component. The credential statements identify who the client component is. The credential statements may also include authorization statements supplied by any of the auxiliary clients such as statements certifying that the client component is a member of a pre-determined group. The client component may not be a trusted entity for the server component. As long as the server component can verify that the proof resulting from information supplied by the client component is correct, the server component will grant the client component the requested access.
[0012] The one or more assertions are used to instruct how to construct a proof to demonstrate that the client component should be granted the requested access. The one or more assertions may be supplied by the server component and used by the client component to construct a proof demonstrating that the requested access should be granted. Alternatively, the client component may supply one or more assertions and credential statements to the server component, which then constructs a proof to demonstrate that the access request should be granted. An assertion may assign a value to a variable or prove a prerequisite clause in one of the credential or use policy statements. In accordance with one aspect of the invention, the one or more assertions may instruct how to construct only part of, instead of the entire proof that is necessary to decide whether the requested access should be granted or not.
[0013] Another aspect of the invention provides a method where a server component sends a client component a proposition upon receiving an access request from the client component. The proposition includes additional assertions that help the client component to construct a proof demonstrating that the client should be granted the requested access.
[0014] A further aspect of the invention provides a method where a client component sends an access request to a server component, along with credential statements and additional assertions. The additional assertions instruct the server component on how to use the credential statements to derive a conclusion on whether to grant the requested access.
[0015] Regardless of whether it is the client component or the server component that supplies the additional assertions, the server component will examine the proof resulting from applying the additional assertions and decide whether the proof is correct. If the proof is correct, the access request will be granted. Otherwise, the access request will be denied. In summary, the invention mitigates the problem presented by onerous computing of proofs by presenting supporting statements, i.e., additional assertions that help to safely and efficiently construct and verify proofs. Consequently, the invention reduces a resource manager's task to simply checking the validity of a proof, instead of computing the proof to decide whether to grant the requested access.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0017] FIG. 1 is a block diagram illustrating an exemplary system for implementing aspects of the invention;
[0018] FIG. 2 is a textual diagram illustrating an exemplary use policy statement;
[0019] FIG. 3 is a textual diagram illustrating exemplary credential statements supplied by a client;
[0020] FIG. 4 is a textual diagram illustrating exemplary additional assertions that help the proof of an access request;
[0021] FIG. 5 is a textual diagram illustrating exemplary integrated statements that are results of integrating the use policy statement illustrated in FIG. 2 , the credential statements illustrated in FIG. 3 , and the additional assertions illustrated in FIG. 4 ;
[0022] FIG. 6 is a flow diagram illustrating an exemplary routine for a server to process an access request; and
[0023] FIG. 7 is a flow diagram illustrating an exemplary routine for a client to seek permission to access a resource on a server.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] FIG. 1 is a block diagram illustrating an exemplary system 100 that implements aspects of the invention. As shown in FIG. 1 , the system 100 includes a server 102 component (“server”) and a client 104 component (“client”), and optionally one or more auxiliary clients 112 . The server 102 includes at least one resource 106 and a corresponding use policy 108 that dictates who can access the resource 106 . The server 102 may further include a resource manager 110 that examines access request and credentials 118 submitted by the client 104 and/or the auxiliary clients 112 . The client 104 is any entity that requests to access the resource 106 on the server 102 .
[0025] The system 100 may be supplemented by one or more auxiliary clients 112 . An auxiliary client 112 can supply information to either the server 102 or the client 104 . For example, if the client 104 is a company, an auxiliary client 112 can be a subsidiary or a partner of the company. In exemplary embodiments of the invention, an auxiliary client 112 may have its own associates, each of which may also have its own associates, and so on. All the different layers of associates are considered aggregately the auxiliary clients 112 .
[0026] The client 104 sends to the resource manager 110 an access request and/or credentials 118 for accessing the resource 106 . The credentials, i.e., the credential statements, are used to prove that the client 104 is eligible to access the resource 106 . The credential statements may be supplied by the client 104 and/or one or more auxiliary clients 112 . An auxiliary client 112 may send credential statements to the client 104 or directly to the server 102 . The resource manager processes the received access request and credentials 118 and decides whether to grant the requested access according to the use policy 108 . The resource manager then sends a decision 120 concerning the access request back to the client 104 .
[0027] More importantly, in exemplary embodiments of the invention, the system 100 also includes additional assertions 114 . The additional assertions may be provided to the server 102 by the client 104 and/or one or more auxiliary clients 112 . In such a situation, the additional assertions 114 will instruct the resource manager 110 on how to process the received credentials to satisfy the requirements specified by the use policy 108 . In some exemplary embodiments of the invention, the additional assertions 114 can be supplied by the resource manager 110 to the client 104 upon the resource manager 110 receiving an access request from the client 104 . The client 104 uses the additional assertions 114 to construct a proof for requesting access to the resource 106 . The additional assertions 114 relieve the resource manager 110 from computing a proof for deciding whether to grant an access request. Instead, the additional assertions 114 enable the resource manager to only examine the correctness of a proof. FIG. 4 illustrates exemplary additional assertions and will be described in detail later.
[0028] The system 100 is only an exemplary implementation to illustrate where the invention is applicable. Components of the system 100 may exist on a single computer system or distributed over a network. Generally speaking, the system 100 can exist in any context where a component such as the server 102 needs another component such as the client 104 to provide information to make a decision such as the decision 120 to grant requested access to the resource 106 . Such a context includes, for example, a server machine to another server machine, a client machine to another client machine, two entities within the same machine, and two different processes within a trusted network. In summary, the invention is applicable anywhere where one entity needs information from another entity in order to make a decision.
[0029] Exemplary embodiments of the invention use access control languages that represent use policy, credential statements, and assertions in a logic form, as opposed to merely data. In a distributed access control system, the client 104 may delegate multiple layers of auxiliary clients 112 to issue credential statements necessary for requesting access to a resource. If data were used for credential statements, at each level of transferring the data from one entity to another entity, the meaning of the data needs to be examined and computed. On the other hand, if the credential statements were represented in logical formats, the distributed access control system will be able to scale smoothly and infinitely since the expression of a credential statement reveals the inherent meaning.
[0030] In exemplary embodiments of the invention, statements such as use policy statements and credential statements employ three concepts that are widely used in many access control languages. The first concept is the use of variables in a policy statement. For example, the use policy 108 for the resource 106 may state that “Parama can read X,” where the variable “X” represents a universally quantified variable, i.e., the variable X can take any value. A policy statement may also include constraints limiting the values that a variable X can take. For example, the use policy 108 may state that “Parama can read X where X is a text file.” The second concept utilized by statements in the invention is that a policy statement has the ability to specify who can authorize credential statements or assertions for accessing a resource. For example, the use policy 108 may state that “acme.com can make assertions permitting access to the resource 106.” Statements in exemplary embodiments of the invention also employ the third concept, which allows a statement to predicate assertions based upon other assertions. For example, the use policy 108 may state that “Parama can access the resource 106 , provided that Parama is a Company A employee, according to Company A.”
[0031] In an exemplary embodiment of the invention, the client 104 and/or one or more of the auxiliary clients 112 may possess the relevant credential statements. Alternatively, the credential statements may be stored somewhere else. Then only references to the credential statements are sent to the server 102 .
[0032] FIGS. 2-5 illustrate an exemplary use policy statement 200 , credential statements 300 , additional assertions 400 , and integrated statements 500 that integrate the use policy statement 200 , the credential statements 300 , and the additional assertions 400 . The exemplary statements used in FIGS. 2-5 represent or combine the three concepts described above. FIGS. 2-5 will be described with reference to FIG. 1 . The entities used in these exemplary statements reflect exemplary components of the system 100 . For example, Contosa.com may be the server 102 ; Parama may be the client 104 requesting to access Web service on Contosa.com; Fabrikam.com and the Fabrikam.com partner Acme.com may be the auxiliary clients 112 .
[0033] FIG. 2 illustrates one exemplary use policy statement 200 that may be supplied by a use policy such as the use policy 108 . The use policy statement 200 recites: Contosa.com says “X can access the Contosa.com Web service if X is a gold star member authorized by Fabrikam.com.” Assume X is a client requesting to access the Contosa.com Web service. According to the use policy statement 200 , if X can prove that it is a gold star member authorized by Fabrikam.com, then X can gain access to the Contosa.com Web service.
[0034] In a distributed access control system such as the system 100 , when the level of distribution increases, the server 102 may not know the client 104 . The server 102 may rely on other entities to make statements about a client. Therefore, credential statements that a server 102 receives from a client 104 may contain credential statements supplied by several entities, including the client 104 and/or one or more auxiliary clients 112 . FIG. 3 illustrates a set of credential statements 300 that the server Contosa.com may receive from the client Parama and/or the auxiliary clients Fabrikam.com and Acme.com. As shown in FIG. 3 , the credential statement 300 A recites: Fabrikam.com says “X can issue gold star member certifications if X is a Fabrikam.com partner.” This statement also implies--that Fabrikam.com designates who Fabrikam.com partners are. The credential statement 300 B recites: Fabrikam.com says “Acme.com is a Fabrikam.com partner.” The credential statement 300 C recites: Acme.com says “Parama is a gold star member.”
[0035] Now assume Parama makes an access request to Contosa.com and presents the credential statements 300 . Conventionally, the resource manager of Contosa.com needs to work through the use policy statement 200 and the credential statements 300 to compute a proof on whether Parama should or should not have the requested access. The resource manager looks through each of the credential statements in order to decide which credential statement is applicable to the use policy. The credential statements provide a cascading logic that enables the resource manager to make the decision. The computing process performed by the resource manager can get arbitrarily complicated if the resource manager receives many credential statements, which can happen, for example, when many layers of auxiliary clients are involved in providing credential statements for Parama. When there are many credential statements, it becomes intractable for the server to arrange the credential statements in a way to induce the proof. Most likely, the computing process may never end. The server 102 can potentially need unbounded search space and cannot know a priori how long it actually takes to figure out whether to grant the requested access or not.
[0036] One aspect of the invention addresses this issue by providing additional assertions that instructs on how to construct a proof, using the relevant credential statements. For example, an assertion can assign a value to a variable in a use policy statement. An assertion can also instruct the proof of one prerequisite clause in a user policy statement. FIG. 4 illustrates exemplary additional assertions 400 that the exemplary client Parama may supply to the exemplary server Contosa.com. As shown in FIG. 4 , the assertion 400 A recites: Replace X with Parama in Statement #1. The assertion 400 B recites: Replace X with Acme.com in Statement #2. The assertion 400 C recites: Use Statement #3 to satisfy Statement #6. The assertion 400 D recites: Justify Statement #4 with Statement #7. The assertion 400 E recites: Use Statement #8 to satisfy Statement #5.
[0037] The additional assertions 400 advise a resource manager of Contosa.com how to put the credential statements 300 together to arrive at a proof. As a result, instead of facing the potentially undetermined amount of work to establish whether Parama can access the Contosa.com Web service by searching through all species of possible consequences for the credential statements 300 , the resource manager of Contosa.com Web service now only needs to follow the instructions in the additional assertions 400 explicitly. The additional assertions thus enable the invention to provide a systematic and efficient way to process use policy and credential statements to arrive at a proof.
[0038] FIG. 5 illustrates the integrated statements 500 resulted from a resource manager of Contosa.com executing the instructions in the additional assertions 300 on the user policy statement 200 and the credential integrated statement 300 . As shown in FIG. 5 , the integrated statement 500 A recites: Contosa.com says “Parama can access the resource if Parama is a gold star member authorized by Fabrikam.com.” The integrated statement 500 B recites: Fabrikam.com says “Acme.com can issue gold star member certifications if Acme.com is a Fabrikam.com partner according to Fabrikam.com.” The integrated statement 500 C recites: Fabrikam.com says “Acme.com can issue gold star member certifications.” The integrated statement 500 D recites: Fabrikam.com says “Parama is a gold star member.” The integrated statement 500 E thus concludes: Contosa.com says “Parama can access the Contosa.com Web service.”
[0039] Therefore, a resource manager for the exemplary server Contosa.com can use the additional assertions 400 to conclude in a straightforward fashion that Contosa.com has implicitly authorized Parama access to the Contosa.com Web service. When applying each of the additional assertions 400 , all Contosa.com needs to check is that it is possible to apply this assertion. In other words, the entity presenting the assertions cannot make Contosa.com do something that is not implied by the use policy statement 200 and the credential statements 300 .
[0040] Additional assertions can be provided to either a server or a client. Upon receiving additional assertions from a client or auxiliary clients, a resource manager of a server uses the additional assertions to construct a proof and then examines the proof instead of computing the proof. In exemplary embodiments of the invention, as soon as a server receives and reads through a set of credential statements and additional assertions, the server can figure out whether to grant the requested access request or not.
[0041] Alternatively, a server can supply additional assertions to a client. Upon receiving an access request from a client, the server can reply with a proposition. The proposition may include additional assertions to instruct the client on how to construct a proof for the server in order to obtain the requested access. Thus, the server will receive from the client the needed proof. All the server needs to do is to examine the proof to determine whether the proof provides a valid conclusion according to the use policy associated with the requested resource.
[0042] In exemplary embodiments of the invention, a server does not have to trust the proof supplied by a client. The server can check the veracity of the credential statements and the additional assertions. This means that the credential statements and the additional assertions do not have to come from trusted entities, because a resource manager of the server cannot be tricked into believing non-proofs to be proofs. The steps that an assertion asks a resource manager to perform should only create actions that are already implied, such as replacing variables in the use policy. Therefore, a client cannot lie to a server to induce the server to arrive at a proof that is false. If an additional assertion supplied is false, the server cannot find the proof. Additional assertions can only help the server make the proof, but cannot trick the server to make a fake proof. If an additional assertion is false, the server will not be able to arrive at a proof. This is analogous to navigating a maze. Computing a proof is like finding a path out of a maze, which may be difficult. On the contrary, verifying whether a given path is a correct path is much easier: If the given path leads to an exit of the maze, then the given path is a correct path. Additional assertions are equivalent to a “given path.” A set of given additional assertions is correct if they lead the server to arrive at a proof; the set of given additional assertions is incorrect and disregarded if the server cannot arrive at a proof by using them.
[0043] In exemplary embodiments of the invention, the additional assertions provided by a server or a client may only make a partial proof, instead of the whole proof that is necessary for deciding on whether to grant the requested access. For example, a server may decide not to reveal its use policy to any entity. Consequently, the server only supplies additional assertions that enable a client to prove the client's identity as required by the hidden user policy. For instance, Contosa.com may decide not to reveal the use policy statement 200 . Therefore, Contosa.com requires the exemplary client Parama to prove that it is a gold star member authorized by Fabrikam.com, with the client having no knowledge about the use policy statement 200 . Alternatively, a server is associated with a traditional theorem prover that is subject to the danger of endless computing mentioned previously with theorem proving. To alleviate such a danger, the additional assertions can be used to construct the “difficult” parts of the proof, leaving a simple (and safe) variant of traditional theorem proving to fill in the minor gaps. In such an approach, theorem verification and proving work together to provide a safe and expressive computation of proof.
[0044] In an exemplary embodiment of the invention, the server 102 illustrated in FIG. 1 also includes an audit component 116 . The audit component 116 logs and saves a resource manager's reasoning process for granting or not granting a requested access. Information recorded by the audit component 116 may identify the reasoning process and/or the various statements the resource manager processes to arrive at the conclusion. Therefore, the auditing information may reveal not only who accessed the resource, but also why the access was granted. The auditing information is useful for analyzing how the access control system works, who requested a resource, why the request was granted, and how the requests were granted. For example, the audit information may provide that Parama has requested access to a Contosa.com Web service and that the access was granted because Parama was proven to be a gold star member authorized by Fabrikam.com. In an exemplary embodiment of the invention, the audit information includes the set of additional assertions used.
[0045] FIG. 6 illustrates an exemplary routine 600 where a server, such as the server 102 , processes an access request and reaches a decision on whether to grant the access request. Specifically, the routine 600 starts by determining whether the server has received an access request. See decision block 602 . If the server has not received an access request, the routine 600 does not proceed further. If the server has received an access request, the routine 600 proceeds to reply with a proposition that a server wants the client sending the access request to prove before granting the client the requested access. See block 604 . The proposition may identify the use policy for the requested resource. The proposition may also include a proof structure that identifies the relationships among multiple use policy statements and any variable in these use policy statements. The proposition may further include additional assertions that instruct the client on how to substantiate the proof structure. For example, the additional assertions may suggest to a client how to satisfy a condition in a use policy statement and/or to find a specific value for a variable in a use policy statement.
[0046] The routine 600 then waits to receive a proof from the client in response to the proposition. The routine 600 determines whether it has received such a proof. See decision block 606 . If the answer to decision block 606 is NO, the routine 600 proceeds no further. If the routine 600 receives a proof from the client, the routine 600 proceeds to examine the proof. See block 608 . In examining the received proof, the routine 600 determines whether the proof is correct. See decision block 610 . A correct proof demonstrates that the client has the right to access the requested resource and that the proof constitutes true statements. If the answer to decision block 610 is YES, meaning that the received proof is correct, the routine 600 proceeds to grant the access request. See block 614 . On the other hand, if the answer to decision block 610 is NO, meaning the received proof is incorrect, the routine 600 denies the access request. See block 612 . The routine 600 then terminates.
[0047] FIG. 7 illustrates an exemplary routine 700 where a client seeks permission from a server to access a resource of the server. Specifically, the routine 700 starts by determining whether the client wants to access a resource of a server. See decision block 702 . If the answer is NO, the routine 700 does not proceed further. If the client wants to access a resource of a server, the routine 700 sends an access request to the server. See block 704 . The routine 700 then waits to receive a proposition from the server. The routine 700 determines if a proposition has been received. See decision block 706 . If the answer is NO, the routine 700 does not proceed further. If the client does receive a proposition from the server, the routine 700 proceeds to construct a proof, according to the proposition. See block 708 . The proof includes data and logical steps that satisfy the requirements specified in the proposition. If the proposition contains additional assertions that instruct how to construct the proof, the proof will be constructed in accordance with the additional assertions. In the case that the received proposition does not contain additional assertions, the constructed proof includes credential statements that identify who the client is. The constructed proof may also include additional assertions that instruct the server on how to use the supplied credential statements to arrive at a decision on whether to grant the access request. The routine 700 then sends the constructed proof to the server. See block 710 . The routine 700 ends. In an exemplary embodiment of the invention, if the client knows beforehand what the server needs in order to make a decision on an access request, when sending the access request to the server, the client also supplies the necessary credential statements and additional assertions. As a result, the server has no need to send the proposition.
[0048] While the preferred embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. | Supporting statements are provided to help safely and efficiently construct and verify proofs necessary for deciding whether to grant a request from one entity for accessing a resource owned or administered by another entity. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to polyurethane covered rolls for use in various industrial applications such as papermaking, steel making and textile manufacturing. More specifically, this invention is directed to thermally conductive base layers for the polyurethane covering of these industrial rolls, the thermally conductive base layer functioning as a reinforcing layer and, additionally, providing a means for dissipating the heat generated in the polyurethane covering, the heat generation a result of energy loss due to elastic deformation of the roll cover during operation.
2. Description of the Prior Art
Roll coverings fabricated from polymeric or elastomeric materials are used for a wide variety of reasons in many industries. Generally speaking, roll covers perform one or more of the following functions:
1. Support, carry, drive, draw or brake product passing through the nip.
2. Remove or extract liquid from the product passing through the nip.
3. Impregnate or coat product passing through the nip.
4. Calendar or iron product passing through the nip.
5. Texture, emboss, print or imprint a pattern to the product passing through the nip.
6. Laminate layers of product or dissimilar layers of products passing through the nip.
7. Provide protection against corrosion.
The use of polymeric or elastomeric covered rolls adapted for use at high speeds of rotation and under heavy loads or pressures has become increasingly significant in recent years. Of particular interest and significance has been the polyurethane roll cover. The polyurethane roll cover provides excellent load bearing and extraction characteristics, high abrasion and wear resistance with better dynamic performance characteristics as compared to the more conventional elastomeric roll covers (chloroprene, styrene-butadiene, polyisoprene, acrylonitrile-butadiene, etc.)
Among the roll types currently in use are those comprising a rigid metallic structural member called a roll core designed to carry the applied load with a minimum amount of deflection. A resilient covering is sometimes bonded directly to the roll core. In many cases, a base layer and/or an intermediate layer is bonded to the roll core and the resilient roll cover is then bonded to the base or intermediate layer. The process can either be a one-step or two-step process. The base or intermediate layer may be a harder material similar to the cover or it may be made up of a fibrous reinforcing material impregnated with a thermosetting resin. The elastomeric or polymeric covering may be materials such as polyurethane, polyisoprene, chloroprene, styrene-butadiene, acrylonitrile butadiene and the like.
It is also known to utilize internally cooled calendering rolls. U.S. Pat. No. 4,256,034 to Kusters, issuing on Mar. 17, 1983, discloses a paper calendering apparatus comprising a pair of interacting calendering rolls, one of which includes a polyurethane covering. The polyurethane-covered roll additionally comprises means for internally cooling the roll in order to maintain the roll cover temperature below a certain minimum temperature. The Kusters' roll applies a cross-linked polyurethane covering directly to the metal core, there being no intermediate reinforcing member.
U.S. Pat. No. 3,082,683 to Justus, issuing on Mar. 26, 1963, directed attention to the problems associated with heat developed within the rubber coverings which could not be sufficiently dissipated by internal cooling of the roll core. The disclosed solution comprised creating a covering containing a plurality of coolant circulation paths for dissipating the heat developed during deformation of the covering. The elastomeric covering is applied directly to the roll core and the system involves a complicated apparatus for manifolding coolant to the axial coolant passages and recirculating the coolant through a heat exchanger.
Hess, U.S. Pat. No. 3,395,636, discloses the use of a dispersion of finely divided carbon particles distributed throughout the elastomeric covering of a processing roll consisting of an elastomeric covering and a hollow roll core of steel, cast iron or bronze. The elastomeric covering is applied directly to the metal roll core, there being no intermediate resin layer. The only material suggested by Hess for heat dissipation is finely divided carbon particles having a mean diameter particle size in the range of 10 to 40 millimicrons. Additionally, no mention of polyurethane as the elastomeric covering is included in the disclosure.
SUMMARY OF THE INVENTION
One of the limiting factors governing conditions of use for existing polyurethane covered, reinforced rolls is related to heat buildup in the roll cover itself resulting from high energy loss from repeated deformation of the roll cover in use. Present conditions of use involve high speeds, high roll pressures and severe application conditions such as heat, moisture, chemicals, etc. Existing rolls do not have the capability of satisfactorily dissipating the heat buildup. Polyurethane, while providing many advantages, is a poor conductor of heat and also generates, relatively, a large hysteresis. This combination of circumstances has resulted in severe limitations on roll speed and pressures and, additionally, is responsible for numerous roll failures due to increase in elastic deformation heat buildup until the elastic limits of the cover are exceeded. The failures usually occur at the interface between the roll cover and the base layer or as actual "melt downs" of the polyurethane. "Sleeving off" of the entire roll cover is known to occur as well.
Thus a need has continued to exist for a processing roll comprising a hollow metal roll core, an intermediate base layer and a polyurethane cover which has the capability of successfully dissipating the high amounts of heat generated by high deformation energy loss due to conditions of roll pressure, roll speed, and operating conditions of current industrial requirements.
It is an object of this invention to provide a roll comprising a hollow core member, an intermediate base layer or layers and a polyurethane cover, said roll capable of operating at loads and/or speeds higher than those previously attainable.
It is a further object of this invention to provide a roll comprising a hollow core member, an intermediate base layer or layers, and a polyurethane cover having a useful life superior to that of previous rolls.
It is still a further object of this invention to provide a roll comprising a hollow core member, an intermediate base layer or layers and a polyurethane cover having the capability of dissipating heat generated by energy loss due to deformation during operation.
These and other objects are obtained by a roll comprising a hollow metal core member, an intermediate base layer or layers and a polyurethane cover, the intermediate base layer being thermally conductive. The thermally conductive intermediate layer provides a means whereby the heat buildup in the polyurethane cover is conducted through the intermediate layer to the metal roll and thereafter dissipated. Higher roll speeds and roll pressures are obtainable in this way, with increased roll life as well.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut away view of one form of roll structure depicting the hollow metal core member, the intermediate base layer or layers and the polyurethane elastomer cover.
FIG. 2 is a fragmentary enlarged sectional view of the roll of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, roll 10 comprises a hollow metal core element 12, an intermediate thermally conductive base layer or layers 14 and a polyurethane cover 16.
Hollow metal core element 12 is made from metals well known in the roll making industry. Such metals include steel, steel alloys, cast iron, cast steel, and bronze, but are not limited to these metals. Methods of producing the hollow roll core element 12 are well known to the art as is the hollow core roll element itself.
The intermediate thermally conductive base layer or layers 14 comprises a hard polymeric material compounded to have increased thermal conductivity. The hard polymeric materials are vulcanized rubbers and thermosetting resins. Typical vulcanizable rubbers include, but are not limited to, polyisoprene, styrene-butadiene, chloroprene, acrylonitrilebutadiene, carboxylated nitrile and/or blends of these polymers and/or others not listed. Typical thermosetting resins include, but are not limited to, polyesters, phenolics and epoxies. The base layer or layers may be in the form of a structurally independent element or compounded to lend itself for use as an impregnant or coating. In a preferred embodiment, the intermediate base layer or base layers, vulcanizable rubber or thermoset resin is used as an impregnant in combination with reinforcing fibrous material, optionally in the form of a cloth or matt. Suitable reinforcing fibrous materials include, but are not limited to, naturally occurring fibers such as fiber glass, crocidilite and synthetic fibers such as polyester, polyamide, polyacrylonitride, vinyl chloride-acrylonitride copolymers, and the like.
The intermediate base layer or layers is compounded to have increased thermal conductivity by the incorporation of thermally conductive materials such as thermally conductive metals in the form of wire, woven or knitted wire in the form of cloth, tape or fabric, composite fabrics woven of thermally conductive materials in combination with non-thermally conductive materials, or wire cord. Typical thermally conductive metals include steel, stainless steel, bronze, copper and aluminum. Applicant does not intend, however, that the above list be limiting, rather, only exemplary.
Other thermally conductive materials include metallic flake, powder, chopped metallic fibers and other thermally conductive reinforcing fillers and pigments such as carbon black, graphite, silicon carbide and petroleum coke. Within the contemplation of the instant invention are those embodiments wherein a thermoset resin or vulcanizable rubber is compounded with the last-mentioned thermally conductive materials and used alone or to impregnate or coat the fibrous reinforcing materials above. The intermediate layer typically has a thickness in the range of 2 to 7 mm.
The polyurethane elastomeric covering 16 comprises those polyurethanes known and used in the art. Typical polyurethane elastomers are TDI and/or MDI terminated resins as polyether, polyester, and/or polyether-polyester blends. The polyurethane cover layer has a typical thickness in the range of 7 to 25 mm, with a preferred thickness in the range of 10 to 15 mm.
Referring now to FIG. 2, a fragmentary sectional enlargement, 12 represents the metal core element, 14 the intermediate thermally conductive base layer, and 16 the polyurethane cover.
In another embodiment of this invention, not shown in the drawings, the hollow metal core element 10 is adapted to be internally cooled by the passage of cooling fluids therethrough. The technology for the internally cooled hollow roll cores is well known. Such an internally cooled roll core and roll is disclosed in U.S. Pat. No. 4,256,034, mentioned above and incorporated by reference hereto.
The polyurethane elastomer covered rolls of this invention may be prepared in the following manner. Referring again to FIG. 1, a suitable roll core 12 is treated to afford proper adhesion of the intermediate base layer 14. Suitable methods of treatment include degreasing with a suitable solvent such as trichloroethane to remove any residual deposits of grease and oil. Following degreasing, the portion of the roll to be coated is then sand- or grit-blasted or otherwise treated with a suitable abrasive material to remove all traces of rust and corrosion and to roughen the surface. The roughening of the outer surface can be achieved by a multiplicity of substantially parallel grooves formed about the circumference of the roll core. However, any other means applicable for roughening the outer surface of the roll core to ensure firm adherence of the intermediate base layer of layers 14 is within the contemplation of the disclosed invention. Alternative methods of roughening the surface include, but are not limited to, tooling, pickling and etching.
In one embodiment of the invention, following the surface preparation of the roll core, an adhesive is applied to the roll core as a prime coat. Suitable adhesive prime coats include, but are not limited to, polyester, phenolic, or epoxy primer coatings. However, application of the primer coat is not required in every instance.
The thermally conductive base layer or layers are then applied to the prepared roll core surface. This thermally conductive base layer or layers may consist of any or a combination of the following materials: (1) a hard polymeric substance which has been compounded specifically for increased thermal conductivity; (2) a thermally conductive hard polymeric substance as above, but compounded additionally to lend itself to be used as an impregnant and coating to impregnate and coat a reinforcing cloth, cloth/wire, wire, woven or knitted wire cloth, or the like; (3) a reinforcing fiber coated and impregnated and further compounded to include thermally conductive materials such as metal flake, metal powder, carbon black and the like. Where the polymeric substance is a vulcanizable material, the composite base structure is then vulcanized or cured, usually in an autoclave. Alternatively, where the polymeric substance is a thermosetting resin, the thermosetting resin is subjected to the appropriate curing step in order to thermoset said resin.
Typical methods of application of the thermally conductive intermediate base layer or layers include lay-up of calendered sheet, either by hand or mechanical means, extrusion, rotational casting and spiral winding.
Following application and vulcanization or curing of the thermally conductive intermediate base layer or layers, the layer or layers are then tooled or ground to a specified size, at the same time providing symmetry to the roll.
The next step in the process of producing the roll involves treating the thermally conductive intermediate base layer in a manner to make it acceptable for bonding of a cast polyurethane roll cover. Various methods of surface preparation are well known in the art. In one embodiment, the heat hardened, thermally conductive layer is washed with a solvent, the layer grit-blasted, rough-machined again to ensure symmetry, and placed in a mold where a suitable polyurethane covering material is cast to the intermediate base layer. Optionally, an adhesive layer may be applied to the intermediate base layer prior to application of the polyurethane elastomeric coating.
The resulting polyurethane covered roll, more readily dissipates heat generated by hysteresis as a result of roll cover deformation, thereby permitting operation at higher speeds and pressures than previously achieved. Additionally, since the base layer has increased thermal conductivity, internal cooling of the roll cover can be utilized more effectively in a water-cooled roll since the effects of the water cooling passing through the interior of the roll core help cool the critical areas within the roll cover and/or at the roll coverbase layer interface.
Having now generally described the invention, the same will be better understood by reference to certain specific examples, which are included herein for purposes of illustration only and are not intended to be limiting of the invention or any embodiment thereof, unless specified.
EXAMPLE 1
A base layer to be applied to a roll core is rendered thermally conductive either by the addition of thermally conductive materials such as metallic powders or chopped metallic fibers to a commercially available thermally conductive impregnating resin, such as Conapoxy FR-1259 [thermal conductivity of 7 BTU/(sq ft ) (hr.) (°F./in.)] and/or the reinforcing fabrics, cloths, mattes containing, as part of their makeup, continuous threads of metal or metal fibers such as stainless steel [113 BTU/(sq ft) (hr.) (°F./in.)] aluminum [1500 BTU/(sq ft) (hr.) (°F./in.)] bronze [1300 BTU/(sq ft) (hr.) (°F./in.)] or the like.
The thermally conductive base layer is applied to a properly prepared roll core by any of the methods conventional to the art. After the base layer has been thermally set, the layer is then tooled and/or ground to a specified size, and prepared to accept the cast polyurethane covering.
EXAMPLE 2
An elastomer, compounded similar to Formula 1 below, is applied to a properly prepared roll core either through extrusion of the compound onto the roll core or by lay-up of calendared sheet to the roll core, both methods state-of-the-art manufacturing procedures. The base layer is vulcanized in an autoclave, then tooled and/or ground to a specified size, and prepared to accept the cast polyurethane covering.
EXAMPLE 3
The base layer, compounded similar to Formula 1, is put into solution (30-70% solids) and spread coat onto a reinforcing thermally conductive cloth, matte, metallic woolen matte, etc., impregnating and coating the reinforcing material. This coated, dried material is then either spirally wound onto a properly prepared roll core in the form of a tape or plied up onto the roll core to a specified thickness. The base is then vulcanized in an autoclave, tooled and/or ground to a specified size and prepared to accept a cast polyurethane covering.
EXAMPLE 4
The base layer, compounded similar to Formula 1, is applied (on a calendar) onto a reinforcing thermally conductive cloth, matte, metallic woolen matte as a skim coating, penetrating into the interstices as well as coating the surfaces of the reinforcing material. This skimmed, thermally conductive reinforcing material is then either plied up or spirally wound as a tape onto a properly prepared roll core to a specified thickness. The base is then vulcanized in an autoclave, tooled and/or ground to a specified size and prepared to accept the cast polyurethane covering.
______________________________________FORMULA 1Hard Base Compound RHC______________________________________NBR 100.00Hard NBR Dust 50.00Fine Metallic Powder 50.00Bronze Wool Chopped 20.00Dioctyl Phthalate 25.00N650 Black 40.00Coumarone Indene Resin 10.00Zinc Oxide 5.00Stearic Acid 1.00Butyraldehyde Aniline 1.00Sulfur 40.00 340.00______________________________________
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit and scope of the invention as set forth herein. | A roll comprising a hollow metal core member, an intermediate base layer or layer, and a polyurethane cover, the intermediate base layer compounded to have improved thermal conductivity. The intermediate base layer or layers having improved thermal conductivity function to dissipate heat generated by hysteresis (deformation energy), thereby permitting the rolls to operate at higher roll speeds and higher pressures without roll failure. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 11/431,251 filed on May 10, 2006. The entire disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
The present invention sets forth a method for exchanging information between an antenna and a satellite receiver so that tuning information and parameters may be exchanged between them.
BACKGROUND
Satellite television has become increasingly popular due to its wide variety of programming. Current DirecTV systems employ an antenna that is fixed to a structure. The antenna is pointed once and secured into place.
Entertainment in automobiles such as DVD players has also become increasingly popular. It would be desirable to provide a satellite television system for a vehicle so that the wide variety of programming may be enjoyed by the rear passengers. In vehicles the antenna must continually move as the vehicle moves to maintain a connection with the satellite receiver. Current satellite receivers do not know information about the antenna and the antenna does not know information about the receiver. Therefore, the time to perform certain tasks may be increased. Currently, mobile satellite service uses standard set top boxes (IRDs). The designs of the IRDs change nearly every year. This increases the challenge for a reliable system particularly in view of the ever-changing antenna designs.
It would therefore be desirable to provide a method and apparatus for performing two-way communications between a receiver and an antenna so that various information may be exchanged between them.
SUMMARY OF THE INVENTION
The present invention allows a mobile antenna to communicate information as to searching, tracking and the acquisition of a good signal to a satellite receiver. Advantageously, this information will provide a minimum disruption to the user and improve the overall perceived quality of the system.
The invention provides a means of communication, command and control between a mobile antenna and a satellite receiver that allows the receiver to send tuning information to the antenna and the antenna to provide feedback to the receiver when a signal has been acquired. The antenna and the receiver can share the appropriate states and stats such as diagnostics, test, GPS coordinates, etc. Various mobile vehicles with satellite receivers such as cars, SUVs, boats RVs, trains and airplanes may benefit from this invention.
Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a system level view of a satellite broadcasting system according to the present invention.
FIG. 2 is a block diagrammatic view of a vehicle having a receiving system according to the present invention.
FIG. 3 is a flow chart illustrating a method of storing communicating between an antenna and a receiving unit according to the present invention.
FIG. 4 is a signaling chart illustrating a method for communicating according to the present invention.
DETAILED DESCRIPTION
In the following figures the same reference numerals will be used for the same views. The following figures are described with respect to a mobile satellite television system. However, those skilled in the art will recognize the teachings of the present invention may be applied to various types of mobile reception including land-based type systems.
Referring now to FIG. 1 , a satellite television broadcasting system 10 is illustrated. The satellite television broadcasting system 10 includes a network operations center 12 that generates wireless signals through a transmitting antenna 14 which are received by a receiving antenna 16 of a satellite 18 . The wireless signals, for example, may be digital. A transmitting antenna 20 generates signals directed to various receiving systems including stationary systems such as those in the home as well as mobile receiving systems 22 . The wireless signals may have various types of information associated with them including location information. The wireless signals may also have various video and audio information associated therewith. As illustrated, the mobile receiving system 22 is disposed within an automotive vehicle 24 . A receiving antenna 26 receives the wireless signals from the satellite 18 and processes the signals in a mobile receiving unit 28 . The mobile receiving unit 28 will be further described below.
The system 10 may also receive location signals from a GPS system 30 that includes a first satellite 32 A and a second satellite 32 B. Although only two satellites are shown, a typical GPS system includes several satellites, several of which may be in view at any particular time. Triangulation techniques may be used to determine the elevation, latitude and longitude of the system. A locating system may also include cellular towers 34 A and 34 B that may be used by the mobile receiving system 22 to determine a location. Cellular phones typically include a GPS locating system. As the vehicle 24 moves about, the exact coordinates in latitude and longitude may be used to determine the proper designated marketing area for local television and broadcasting.
The present invention may also be used for displaying various wireless information on a personal mobile device 36 such as a laptop computer 38 , a personal digital assistant 39 , and a cellular telephone 40 . It should be noted that these devices and the automotive-based devices may also receive wireless signals having various types of information associated therewith from the cellular towers 34 A and 34 B. Other types of information may be broadcast from various other types of broadcasting areas such as an antenna 42 on a building 44 . The building 44 may be various types of buildings such as a store and the wireless information transmitted from the antenna 42 may be advertising information. All of the wireless signals preferably include location information transmitted therewith. As will be described below, the information may be coded digitally into the signals. Thus, by reviewing the location information, signals appropriate for the location of the mobile devices may be displayed on the various devices.
Referring now to FIG. 2 , a receiving system 22 is illustrated in further detail. Antenna 26 may be various types of antennas including a moving or rotating antenna which is used to track the relative movement of the satellite or other transponding devices with respect to the vehicle. The antenna 26 may be a single antenna used for satellite television reception, or a number of antennas such as one for receiving television signals and one coupled to a GPS location receiver 50 . The antenna 26 may also be an electronic antenna. As will be further described below, the antenna 26 may two-way communicate information to the mobile receiving unit 28 . The two-way communication principles set forth herein may also be applied to stationary antennas.
The antenna 26 may include a control module 27 that controls the communication with the receiving unit 28 . The control module 27 may also control the movement of the antenna 26 as the vehicle moves. During operation, the control module 27 generates various types of signals such as information regarding the antenna, timing information and the like as will be described below.
The mobile receiver unit 28 is coupled to antenna 26 with a two-way communication channel such as a wire or a wireless system. The mobile receiving unit 28 may also include a location receiver 52 integrated therein. The location receiver 52 may be a GPS receiver. In a preferred embodiment, only one location receiver 50 , 52 may be provided in the system. However, the location receiver 50 , 52 may be part of the vehicle 24 or may be part of the mobile receiving system 22 , 36 . The controller 60 may be coupled directly to location receiver 52 and/or location receiver 50 . The mobile receiving unit 28 includes a display 54 . The display 54 may be incorporated into the device 36 or within the vehicle 24 . The display 54 may include output drivers 56 used for generating the desired audio and video outputs suitable for the particular display 54 .
A controller 60 may be a general processor such as a microprocessor. The controller 60 may be used to coordinate and control the various functions of the receiving unit 28 . These functions may include a tuner 64 , a demodulator 66 , a forward error correction decoder 68 and any buffers and other functions. The tuner 64 receives the signal or data from the individual channel. The demodulator 66 demodulates the signal or data to form a demodulated signal or data. The decoder 68 decodes the demodulated signal to form decoded data or a decoded signal. The controller 60 may be similar to that found in current DirecTV set top boxes which employ a chip-based multifunctional controller.
The controller 60 may include or be coupled to a local bus 70 . The local bus 70 may be used to couple a dynamic memory 72 such as RAM which changes often and whose contents may be lost upon the interruption of power or boot up. The bus 70 may also be coupled to a non-volatile memory 74 . The non-volatile memory may be an in-circuit programmable type memory. One example of a non-volatile memory is an EEPROM. One specific type of EEPROM is flash memory. Flash memory is suitable since it is sectored into blocks of data segments that may be individually erased and rewritten.
Other memory devices 76 may also be coupled to local bus 70 . The other memory devices may include other types of dynamic memory, non-volatile memory, or may include such devices such as a digital video recorder. The display 54 may be changed under the control of controller 60 in response to the data in the dynamic memory 72 or non-volatile memory 74 .
The controller 60 may also be coupled to a user interface 80 . User interface 80 may be various types of user interfaces such as a keyboard, push buttons, a touch screen, a voice activated interface, or the like. User interface 80 may be used to select a channel, select various information, change the volume, change the display appearance, or other functions. The user interface 80 is illustrated as part of the mobile receiving unit. However, should the unit be incorporated into a vehicle, the user interface 80 may be located external to the mobile receiving unit such as dial buttons, voice activated system, or the like incorporated into the vehicle and interface with the mobile receiving unit.
A remote control 86 may be used as one type of interface device. The remote control 86 provides various data to the controller 60 .
A conditional access module card 82 (CAM) may also be incorporated into the mobile receiving unit. Access cards such as a conditional access module (CAM) cards are typically found in DirecTV units. The access card 82 may provide conditional access to various channels and wireless signals generated by the system. Not having an access card or not having an up-to-date access card 66 may prevent the user from receiving or displaying various wireless content from the system.
An external data port 84 may be coupled to the controller 60 for transmitting or receiving information from a device. The receiving device is illustrated having a data port 84 that is coupled to antenna 26 . The data port 84 provides two-way communication between the antenna 26 and the controller 60 through a two-way communication line 85 . The connection between the data port 84 and the antenna 26 may be one of a number of types of connections including an RS 232 type connection, a USB connection, a wired connection, a wireless connection or the like. A dedicated port from controller 60 may be used to communicate in addition to other data ports.
In FIG. 3 , step 210 starts the two-way communication system. Handshaking techniques are implemented to ensure proper communications are sent and received. In step 212 a command parser is reset. In step 214 , a command prefix is sent from the receiver box to the antenna (or vice-versa). In step 216 , the command parser attaches to a data port and sends the command which corresponds to the parser being in use. The command sent provides an alert that the receiving unit is going to send the antenna some information. In step 218 , if a contention is not detected, step 220 is executed. A contention is detected when both the receiver unit and the antenna are trying to communicate at exactly the same time. If no contention is detected, a determination of a positive response has been received. If a positive response has been received and the ACK_CMD response is provided, the antenna is acknowledging the command from the receiver unit. In step 224 , it may be possible to send a multiple byte command. If a multiple byte command has been sent in step 224 , the system proceeds to step 226 . In step 226 , it is determined whether the correct number of parameters has been sent for the particular command. In step 230 , if the response has been received (ACK_PARAMS) the parameters have been properly received by the antenna. In step 224 , if a multiple byte command is not provided, or after step 230 , step 232 allows the system to execute the desired command. In step 234 , it is determined whether the command has been completed successfully. If the command has been completed successfully, a response acknowledging this is provided from the antenna. This response may take the form of an acknowledge function OK command (ACK_FCNOK), and thus the parser is freed in step 236 . Referring back to step 234 , if the command has not been successfully completed, step 238 is executed in which a no acknowledge signal (NACK_FCNOK).
In step 228 , if the parameters have not been acknowledged, a no acknowledge parameter signal is provided (NACK_PARAMS) and step 240 is generated. If a positive response has not been received and a no acknowledge parameter is provided in step 224 or the command is not successfully completed and a no acknowledge function is generated in step 238 , step 212 is again executed.
It should be noted that at any time a response such as an acknowledge reset in step 250 , a data error in step 252 , or a command buffer overflow in step 254 may be received by either device. In either case, the system jumps from where it is in the program loop and resets the command parser in step 212 .
Referring back to step 218 , if a contention has been detected, step 260 is executed. In step 260 , the response command prefix and command may be received. To indicate a contention, a response of no acknowledge busy (NACK_BUSY) may be provided in 262 or in step 264 a no acknowledge busy response (NACK_BUSY) may be received. In step 266 , a wait for a random backoff time may be performed while another try is made at generating a communication. By waiting a random time, the two devices will likely not try to communicate simultaneously. After step 266 , step 212 is executed in which the command parser is reset.
Referring now to FIG. 4 , a communication diagram of the handshaking between the module antenna and receiver is set forth. As an overview, there are three main states: boot-up, program guide acquisition, and channel tuning. A summary of each is set forth below:
Boot Up
Once the receiver comes out of reset and starts executing, it will wait for capabilities and other information from the antenna. Upon reception of AntennaInfo, the receiver checks the antenna capabilities and enables two-way communications with the antenna.
Program Guide Acquisition—Boot Stage
During Program Guide Acquisition boot, the receiver tunes to different transponders and possibly different satellites. The receiver will make use of the ReportDesiredTuningInfo to indicate to the antenna the required satellite and transponder. This process is the same as when tuning to a video channel (see Channel Tuning below).
Channel Tuning
When tuning to a channel, the receiver will make use of the ReportDesiredTuningInfo to indicate to the antenna the required satellite and transponder. The antenna receives the command and sends back a status/state response. It scans for the appropriate satellite. The receiver waits for a status that indicates the antenna has completed its process to track the appropriate satellite. The receiver acquires further information from the satellite to confirm that the antenna is tracking correctly and sends back ReportActualTuningInfo. The receiver and antenna exchange status/state information until the next channel change.
In FIG. 4 , a boot-up phase of the system is illustrated. The left side illustrates the receiving device or IRD and the right illustrates an antenna. During boot up the IRD may send a request antenna information request to the antenna or the antenna may send its information to the receiver box without prompting. The receiving device generating a request is provided in box 300 and transmits the request antenna information signal in step 302 to the antenna 304 . The antenna may respond with antenna information in step 306 . In box 308 , the receiving device may request or send various tuning information such as it desires to receive the automatic program guide (APG) or it may be desired to tune to a new channel. This is illustrated in step 310 , report desired tuning info. In box 312 , the antenna may search for the particular satellite or the like. In box 314 the antenna may send a status state in step 316 to the receiving device in step 318 . In step 320 , the antenna may also provide tracking information or the like with a send status state signal in step 322 to the receiving device in step 324 . In step 326 , the receiving device may report actual tuning information in step 328 to the antenna 330 in which the desired tuning information is tracked. This may be due to a channel change or the like. This may be performed when a successful tuning to a particular channel is performed. Every once in a while the antenna may provide information in step 340 by providing a send status state signal 342 to the IRD 344 . This may be performed every once in a while such as every 30 seconds, or every time a status changes.
A list of various commands is provided in Table 1. The “get” commands are commands that the antenna or receiver generates to request information. The report commands are commands that provide information to the other device. Thus, as can be seen, two-way communication between a receiver and an antenna is provided in the present invention. This allows the tuner or receiving device to have information as to the status of the antenna. The antenna also has information regarding the status of the receiving device.
TABLE 1
Command
Description
GetDesiredTuninginfo
Command signal generated by the antenna. The
receiver responds with desired (not tuned yet) tuning
information.
GetActualTuninginfo
Command signal generated by the antenna. The
receiver responds with the actual tuning information.
SetAntennainfo
This command signal sets the antenna information
within the receiver which allows the receiver to
enable/disable related features.
ReportAntennaState
The antenna provided status information signal to the
receiver.
GetReceiverStatus
This command signal gets the state of the receiver.
GetCurPrograminfo
This command signal retrieves the programming
information associated with the current channel.
Getreceiverinfo
This command signal gets information about the
receiver.
ReportGPSLocation
This command signal informs the receiver of the
current GPS location.
ReportDesiredTuninginfo
Command signal generated by the receiver any time
there is a channel change. Desired tuning information
is provided with command.
ReportActualTuninginfo
Command signal generated by the receiver any time
there is a channel change and the receiver has tuned
successfully to a channel.
GetAntennaDiagnostic
Command signal generated by the receiver to retrieve
and display antenna diagnostics information.
GetAntennaInfo
Command signal generated by the receiver to retrieve
and display antenna information.
While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims. | A system and method to provide a means of communication, command and control between a mobile antenna and a satellite receiver that allows the receiver to send tuning information to the antenna and the antenna to provide feedback to the receiver when a signal has been acquired. The antenna and the receiver can share the appropriate states and status such as diagnostics, test, GPS coordinates, etc. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a solar cell. Also, the present invention relates to a method for manufacturing such a solar cell.
BACKGROUND
[0002] Solar cells with back-side contacts are known in the art. In such solar cells the contact layers have been arranged virtually completely on the back-side of the solar cell substrate. In this manner, the area of the front-side of the solar cell that can collect radiative energy can be maximized.
[0003] On the back-side, contact structures are used to collect photogenerated charge carriers entirely from the back of the cell.
[0004] Such contact structures may comprise p-type and n-type heterostructure junctions (heterojunctions) that are interdigitated.
[0005] Solar cells of this type are for example known from US 2008/0061293 that discloses a semiconductor device with heterojunctions and an inter-finger structure. Such a semiconductor device includes, on at least one surface of a crystalline semiconductor substrate, at least one first amorphous semiconductor region doped with a first type of conductivity. The semiconductor substrate includes, on the same at least one surface, at least one second amorphous semiconductor region doped with a second type of conductivity, opposite the first type of conductivity. The first amorphous semiconductor region, which is insulated from the second amorphous semiconductor region by at least one dielectric region in contact with the semiconductor substrate, and the second amorphous semiconductor region form an interdigitated structure.
[0006] A disadvantage of such a semiconductor device is that the dielectric region does not collect photo-generated carriers. In addition, the dielectric region needs to passivate the surface very well. Moreover, the fabrication of such a patterned dielectric region requires additional process steps which increase the cost of the solar cell.
[0007] Furthermore, in case the semiconductor layers comprise amorphous silicon, deposition of a passivating dielectric layer would commonly be restricted to be before deposition of the semiconductor layers, because deposition of most passivating dielectrics is performed at relatively high substrate temperatures which will deteriorate the passivation created by amorphous silicon layers. This sequence of depositions implies that the dielectric has to be removed on the surface portions where the semiconductor layers will be deposited, which adds an additional risk of surface damage or contamination, and therefore a loss of solar cell quality.
[0008] WO 2012/014960 A1 discloses a process for production of a back contact solar cell wherein a second semiconductor layer is formed to cover a first principle surface. A portion of the second semiconductor layer located on a insulating layer is partially removed by etching using a first etchant whose etching rate is higher for the second semiconductor layer than for the insulating layer. A portion of the insulating layer is removed by etching from above the second semiconductor layer using a second etchant whose etching rate for the insulating layer is higher than that for the second semi-conductor layer, thereby exposing a first semiconductor region. Moreover, WO2012/014960 discloses “a semiconducting layer located under insulating layer is used as n-type amorphous semiconductor layer. Then p-side electrode is formed substantially entirely on p-type amorphous semiconductor layer. For this reason, holes which are minority carriers can be easily collected to p-side electrode.”
[0009] It is an object of the present invention to provide a solar cell and a method for manufacturing such solar cell that overcome the disadvantages of the prior art.
SUMMARY OF THE INVENTION
[0010] The object is achieved by a solar cell comprising a semiconductor substrate, the semiconductor substrate having a front side surface for receiving radiation and a back-side surface provided with a first junction structure in a first area portion of the substrate and with a second junction structure in a second area portion of the substrate; the second area portion bordering on the first area portion;
[0011] the first junction structure comprising a first conductivity type semiconductor layer covering the first area portion;
[0012] the second junction structure comprising a second conductivity type semiconductor layer covering the second area portion;
[0013] the second conductivity type semiconductor layer of the second junction structure partially overlapping the first conductivity type semiconductor layer of the first junction structure,
[0014] the overlapping portion of the second conductivity type semiconductor layer being above a portion of the first conductivity type semiconductor layer while separated by a first dielectric layer therebetween, and
[0015] the portion of the first conductivity type semiconductor layer under the overlapping portion of the second conductivity type semiconductor layer is in direct contact with the semiconductor surface of the substrate,
[0016] wherein the second conductivity type semiconductor layer in the second area portion borders on the first conductivity type semiconductor layer in the first area portion, adjacent to the overlapping portions of the first and second conductivity type semiconductor layers.
[0017] Direct contact in this context means that a surface of the portion of the first conductivity type semiconductor layer is on the substrate surface of the semiconductor without an electrically insulating layer in between.
[0018] Bordering or immediate bordering means in this context that the second area portion is adjacent to or is in closest approach or abuts the first area portion without an intermediate dielectric material between the two area portions.
[0019] Advantageously, the invention provides that due to the immediate bordering, the collecting areas for the photo-generated charge carriers are maximized without gaps in-between the first and second junction structures. Moreover, by allowing only first and second conductivity type semiconductor layers on the semiconductor of the substrate and excluding first dielectric layers on the substrate in between the first and second junction areas, a better passivation can be achieved which reduces recombination effects and improves the solar cell's efficiency. Furthermore, in case the semiconductor layers comprise amorphous silicon, deposition of a passivating dielectric layer would commonly be restricted to be before deposition of the semiconductor layers, because deposition of most passivating dielectrics is performed at relatively high substrate temperatures which will deteriorate the passivation by amorphous silicon layers. This sequence of depositions implies that the dielectric has to be removed on the surface portions where the semiconductor layers will be deposited, which adds an additional risk of surface damage or contamination, and therefore a loss of solar cell quality. The present invention does not require the use of surface-passivating dielectrics, and therefore allows more flexibility in the choice of material and deposition temperature for dielectric layers.
[0020] The invention allows a very useful manufacturing tolerance in the definition of the first and second area portions. Although solar cells could be manufactured according to the present invention using any feasible high pattern definition accuracies, the invention allows also to make solar cells with pattern definition accuracies for example worse than 10 micron, or with even less accuracy. In comparison, for prior art solar cell manufacturing such low accuracies could easily result in loss of cell efficiency, for example because of causing shunt, or increasing series resistance, or leaving substrate area unpassivated.
[0021] The invention allows that in addition to substantially fully covering the surface with semiconductor layers, the dielectric layers can be used for pattern definition as masking layer or stopping layer during etching and for isolation. This dual function reduces cost and saves processing steps.
[0022] In an aspect the invention relates to a solar cell as described above, wherein the first junction structure comprises a first tunnel barrier layer, the first tunnel barrier layer arranged between the first conductivity type semiconductor layer and the substrate, and/or wherein the second junction structure comprises a second tunnel barrier layer, the second tunnel barrier layer arranged between the second conductivity type semiconductor layer and the substrate.
[0023] In an aspect the invention relates to a solar cell as described above, wherein at least one of the first junction structure and the second junction structure comprises an epitaxial Si layer, the first conductivity type semiconductor layer being the epitaxial Si layer and/or the second conductivity type semiconductor layer being the epitaxial Si layer.
[0024] In an aspect the invention relates to a solar cell as described above, wherein the interface of the overlapped portion of the first conductivity type semiconductor layer and the substrate surface is void of a dielectric layer.
[0025] In an aspect the invention relates to a solar cell as described above, wherein the first conductivity type is p-type, the first conductivity type semiconductor layer comprises p-type doped amorphous hydrogenated silicon, p+a-Si:H, and the first dielectric layer comprises hydrogenated silicon nitride, SiNx:H.
[0026] In an aspect the invention relates to a solar cell as described above, wherein the first junction structure comprises an additional first conductive layer or layer stack on top of the first conductivity type semiconductor layer.
[0027] In an aspect the invention relates to a solar cell as described above, wherein either the additional first conductive layer is a metallic layer, or the layer stack comprises a conductive oxide layer and an amorphous semiconductor layer, the amorphous semiconductor layer being arranged on top of the stack of the conductive oxide layer and the first conductivity type semiconductor layer.
[0028] In an aspect the invention relates to a solar cell as described above, wherein the second junction structure comprises an additional second conductive layer or layer stack, on top of the second conductivity type semiconductor layer.
[0029] In an aspect the invention relates to a solar cell as described above, wherein either the additional second conductive layer is a metallic layer, or the layer stack comprises a conductive oxide layer and an amorphous semiconductor layer, the amorphous semiconductor layer being arranged on top of the stack of the conductive oxide layer and the second conductivity type semiconductor layer.
[0030] In an aspect the invention relates to a solar cell as described above, wherein the first conductivity type semiconductor layer material comprises an intrinsic amorphous silicon layer or tunnel barrier layer, and a doped layer; the doped layer being one selected from a group comprising a first type doped amorphous silicon, a first type doped silicon-carbon mixture, a first type doped silicon-germanium alloy, first type doped epitaxially grown crystalline silicon, a first type doped poly-silicon.
[0031] In an aspect the invention relates to a solar cell as described above, wherein the second conductivity type semiconductor layer material is one selected from a group comprising a second type doped amorphous silicon, a second type doped silicon-carbon mixture, a second type doped silicon-germanium alloy, second type doped epitaxially grown crystalline silicon; a second type doped poly-silicon, and another semiconductor.
[0032] In an aspect the invention relates to a solar cell as described above, wherein the first dielectric layer material is one selected from a group comprising silicon nitride, silicon dioxide, silicon oxynitride, a dielectric organic compound, a dielectric metal oxide or dielectric metal nitride.
[0033] In an aspect the invention relates to a solar cell as described above, wherein the first junction structure comprises a first tunnel barrier layer, the first tunnel barrier layer arranged between the first conductivity type semiconductor layer and the substrate, and/or wherein the second junction structure comprises a second tunnel barrier layer, the second tunnel barrier layer arranged between the second conductivity type semiconductor layer and the substrate.
[0034] Additionally, the present invention relates to a method for manufacturing a solar cell from a semiconductor substrate, the semiconductor substrate having a front side surface for receiving radiation and a back-side surface provided with a first junction structure in a first area portion of the substrate and with a second junction structure in a second area portion of the substrate, the second area portion bordering on the first area portion; the method comprising:
[0035] depositing on the back-side surface of the substrate over at least the first area portion a first conductivity type semiconductor layer; optionally depositing conducting layers;
[0036] depositing a first dielectric layer over at least the first conductivity type semiconductor layer; patterning the first dielectric layer for defining the first area portion by covering the first conductivity type semiconductor layer in the first area portion and for exposing the second area portion; patterning the first conductivity type semiconductor layer using the patterned first dielectric layer as mask to create the first junction structure in the first area portion and to expose the surface of the silicon substrate in the second area portion; depositing on the back-side surface, a second conductivity type semiconductor layer over at least part of the first dielectric layer bordering the second area portion, and the exposed second area portion, in such a manner that the second conductivity type semiconductor layer of the second junction structure partially overlaps the first conductivity type semiconductor layer of the first junction structure, the overlapping portion of the second conductivity type semiconductor layer being above a portion of the first conductivity type semiconductor layer while separated by a first dielectric layer therebetween, and the portion of the first conductivity type semiconductor layer under the overlapping portion of the second conductivity type semiconductor layer is in direct contact with the semiconductor surface of the substrate.
[0037] In case the optionally deposited conducting layer is a conductive oxide, in the following the dielectric layer maybe replaced by an intrinsic amorphous silicon layer.
[0038] The first conductivity type can be equal to or opposite to the conductivity type of the semiconductor substrate.
[0039] The method according to the present invention allows a self-aligned formation of edges of the first conductivity type layer with edges of the first dielectric layer, maximizing the substrate area covered with active (first or second conductivity type semiconductor layers) while improving isolation between the two semiconductor layers.
[0040] Furthermore, the method advantageously allows that the first dielectric layer functions both for separation of the first and second conductivity type semiconductor layers, as well as for covering the first conductivity type semiconductor layer during the deposition of the second conductivity type semiconductor layer. The covering can protect against the thermal degradation of the passivation by the first conductivity type semiconductor layer during the deposition of the second conductivity type semiconductor layer. This degradation is known to occur in a p-type doped a-Si:H layer during deposition of an n-type doped a-Si:H layer.
[0041] According to an aspect, the method further provides a step of depositing a masking layer over the second conductivity type semiconductor layer that at least covers the second area portion and (the bordering) part of the first area portion, which is followed by patterning the masking layer; and using the patterned masking layer for locally removing the second conductivity type semiconductor layer.
[0042] Alternatively, the second conductivity type semiconductor layer can be etched by a direct method, e.g. by printing an etching paste in the required pattern.
[0043] Optionally, the first dielectric layer can be removed with the second conductivity type semiconductor layer as a mask. This will give a self-alignment of these layers. Advantageously, the method thus allows a self-aligned formation of the edges of the first and second conductivity type layers with the edges of the first dielectric layer, maximizing the areas of first and second conductivity type semiconductor layers exposed for applying a metallization layer, while ensuring isolation between the two.
[0044] In an aspect the method as described above further comprises: depositing a masking layer over the second conductivity type semiconductor layer at least covering the second area portion and part of the first area portion; patterning the masking layer; patterning the second conductivity type semiconductor layer using the patterned masking layer as mask to create the second junction structure in the second area portion with a pattern that provides the second conductivity type semiconductor layer to border on and partially overlap the first conductivity type semiconductor layer, the overlapping portion of the second conductivity type semiconductor layer being on top of the first conductivity type semiconductor layer, separated by the first dielectric layer.
[0045] According to an aspect the method as described above provides that the first junction structure is provided with a first tunnel barrier layer, the first tunnel barrier layer arranged between the first conductivity type semiconductor layer and the substrate, and/or wherein the second junction structure is provided with a second tunnel barrier layer, the second tunnel barrier layer arranged between the second conductivity type semiconductor layer and the substrate.
[0046] In an aspect the method as described above provides that at least one of the first junction structure and the second junction structure comprises an epitaxial Si layer, the first conductivity type semiconductor layer being the epitaxial Si layer and the substrate, and/or the second conductivity type semiconductor layer being the epitaxial Si layer.
[0047] In an aspect the method as described above provides that the first conductivity type is p-type, the first conductivity type semiconductor layer comprises p-type doped amorphous hydrogenated silicon, p+a-Si: and the first dielectric layer comprises hydrogenated silicon nitride, SiNx:H, the p+a-Si:H layer being covered by the SiNx:H layer.
[0048] Advantageous embodiments are further defined by the dependent claims.
BRIEF DESCRIPTION OF DRAWINGS
[0049] The invention will be explained in more detail below with reference to a few drawings in which illustrative embodiments thereof are shown. They are intended exclusively for illustrative purposes and not to restrict the inventive concept, which is defined by the claims.
[0050] In the drawings,
[0051] FIGS. 1 a -1 c show a cross-section of a solar cell after a first manufacturing step;
[0052] FIG. 2 shows a cross-section of a solar cell after a next manufacturing step;
[0053] FIG. 3 shows a cross-section of a solar cell semiconductor substrate after an initial patterning step;
[0054] FIG. 4 shows a cross-section of a solar cell semiconductor substrate after completion of the patterning step of the first semiconductor layer;
[0055] FIGS. 5 a and 5 b show a cross-section of a solar cell after a next manufacturing step;
[0056] FIG. 6 shows a cross-section of a solar cell after a deposition of a masking layer;
[0057] FIG. 7 shows a cross-section of a solar cell after a subsequent patterning step;
[0058] FIG. 8 shows a cross-section of a solar cell after a etching step;
[0059] FIG. 9 a -9 c shows a cross-section of a solar cell after a next manufacturing step;
[0060] FIG. 10 a -10 e show a cross-section of a solar cell after a metallisation step;
[0061] FIG. 11 a -11 c show a cross-section of a solar cell according to an alternative embodiment;
[0062] FIG. 12 shows a cross-section of a solar cell according to an alternative embodiment after a next manufacturing step;
[0063] FIG. 13 shows a cross-section of a solar cell after a removal of a second masking layer and
[0064] FIG. 14 shows a cross-section of a solar cell after a subsequent manufacturing step.
DESCRIPTION OF EMBODIMENTS
[0065] In the following Figures, the same reference numerals refer to similar or identical components in each of the Figures. The solar cell comprises a semiconductor substrate, typically a silicon wafer.
[0066] Such a wafer may be either polycrystalline or monocrystalline.
[0067] The wafer may be textured on at least the front, and it may be provided with a front side passivation by, for example, a front diffused layer and a front passivating coating. It may also be provided with an antireflection coating on the front. The front side texture and coating may also be provided later during the process. The front side may also be provided with sacrificial layers, protecting against some of the processes described below.
[0068] FIG. 1 a shows a cross-section of the semiconductor substrate 5 after a first processing step in a manufacturing sequence. In this step a first conductivity type semiconductor layer 10 is deposited over at least a first portion of the surface of the substrate 5 . The first conductivity type semiconductor layer will form a first junction with the semiconductor substrate surface.
[0069] The first conductivity type semiconductor layer material can be selected from a group comprising a first type doped amorphous hydrogen-enriched silicon (a-Si:H), a first type doped microcrystalline silicon, a first type doped amorphous silicon-carbon mixture, a first type doped silicon-germanium alloy, a first type doped epitaxially grown crystalline silicon, first type doped poly-silicon, or other semiconductor. Additionally, the first conductivity type semiconductor layer may comprise a stack of an intrinsic semiconductor layer and a first type doped semiconductor layer, with materials selected as described above, such as a heterojunction with an intrinsic thin layer (HIT structure), as known in the state of the art.
[0070] The first conductivity type layer may also comprise a surface layer of the substrate, created by diffusion or implantation of doping into the substrate, which may be local or followed by an etch-back outside the first area portion A.
[0071] The first area portion that is covered is at least equal to the area where the first junction will be created.
[0072] Optionally in an embodiment, the first and/or second junctions may comprise metal-insulator- semiconductor (MIS) junctions.
[0073] Figure lb shows a cross-section of a semiconductor substrate after the first manufacturing step, in case the first conductivity type semiconductor layer is covered by a conductive layer 15 that functions as collecting layer and/or parallel conductor to improve current extraction and/or current flow. The conductive layer can for example be a metal layer or a (transparent) conductive oxide layer or a combination thereof.
[0074] Below the invention will be described with reference to an embodiment of the first conductivity type semiconductor layer without conductive layer. It will be appreciated that in an alternative embodiment instead of a first conductivity type semiconductor layer, a stack of the first conductivity type semiconductor layer 10 with the conductive layer 15 can be used.
[0075] It is also noted that as shown in FIG. 1 c , in an embodiment, between the surface of the semiconductor substrate 5 and the first conductivity type semiconductor layer 10 , a thin tunnel barrier layer 10 a may be arranged which layer 10 a provides a tunneling contact for charge carriers between the semiconductor substrate 5 and the first conductivity type semi-conductor layer 10 .
[0076] FIG. 2 shows a cross-section of a solar cell 1 after a next manufacturing step. In a next step, on top of the first conductivity type semiconductor layer, a first dielectric layer 20 is deposited that covers the first conductivity type semiconductor layer at least in the first area portion A.
[0077] It is noted that in case the optionally deposited conductive layer is a conductive oxide, instead of the first dielectric layer, an intrinsic amorphous silicon layer may be deposited.
[0078] The first dielectric layer material may comprise a material selected from a group comprising silicon nitride, silicon dioxide, silicon-oxy-nitride, a dielectric organic compound (such as a “resist” or a resin), a dielectric metal oxide or dielectric metal nitride, and other suitable dielectrics.
[0079] In case the stack in FIG. 1 a 1 b or 1 c ends with a conductive oxide as top layer, it can be beneficial for the choice of available etchants to replace the dielectric layer by an intrinsic amorphous silicon layer.
[0080] FIG. 3 shows a cross-section of the semiconductor substrate after a patterning step of the first dielectric layer. This patterning removes the first dielectric layer from the second area portion B of the semiconductor substrate where a second junction is to be created. In the first area portion A where the first junction is to be created, the patterned first dielectric layer 21 is maintained. According to an aspect of the invention, the first area portion A borders on, is adjacent to, the second area portion B of the semiconductor substrate.
[0081] By the patterning step an interdigitated structure can be defined in which first type junctions are interdigitated with second type junctions.
[0082] The patterning step comprises an etching step, which may be a selective etching step, to remove the first dielectric layer and to expose the first conductivity type semiconductor layer in the areas where the first dielectric layer is removed.
[0083] The patterned first dielectric layer 21 serves as a mask for creating a patterned first conductivity type semiconductor layer 11 . The exposed first conductivity type semiconductor layer is removed from the second area portion B of the semiconductor substrate using an etching step, which may be a selective etching step.
[0084] The patterning of the first conductivity type semiconductor layer is schematically shown in FIG. 4 . Because the pattern of the first dielectric layer is transferred into the pattern of the first conductivity type layer, the edges of the patterns of the two layers are substantially self-aligned. Such self-alignment has advantages of reducing the number of process steps, reducing the required alignment tolerances, and reducing costs.
[0085] FIG. 5 a shows a cross-section of a solar cell after a subsequent step. On the patterned surface a second conductivity type semiconductor layer 25 is deposited over at least the second area portion B of the semiconductor substrate and over at least a bordering portion of the stack of the patterned first dielectric layer 21 and the patterned first conductivity type semiconductor layer 11 which are adjacent to the second area portion B.
[0086] In this structure, the patterned first dielectric layer 21 provides insulation between the second conductivity type semiconductor layer 25 overlapping the patterned first conductivity type semiconductor layer 11 .
[0087] The overlap of the first and second conductivity type semiconductor layers is shown to have a slope. It is noted that the actual slope angle may depend on the actual processing steps and conditions. Also, the slope may be substantially perpendicular to the surface of the substrate, or stepped.
[0088] Additionally, the second conductivity type semiconductor layer 25 borders on the patterned first conductivity type semiconductor layer 11 .
[0089] Because during the etching of the patterned first conductivity type semiconductor layer 11 some undercut (etching of layer 11 under layer 21 ) may occur, the words “borders on” are intended to define that the lateral distance between the two patterned semiconductor layers 11 , 25 is at most a few times the thickness of patterned first conductivity type semiconductor layer 11 .
[0090] For example if patterned first conductivity type semiconductor layer 11 is 20 nm thick, the bordering of the layers means that they are within about 100 nm or less of each other.
[0091] Like the patterned first conductivity type semiconductor layer 11 , layer 25 may be covered with an optional conductive layer, such as transparent conductive oxide (TCO) and/or metal.
[0092] The second conductivity type semiconductor layer material can be selected from a group comprising a second type doped amorphous silicon, a second type doped silicon-carbon mixture, a second type doped silicon-germanium alloy, second type doped epitaxially grown crystalline silicon, second type doped poly-silicon, or other semiconductor. Additionally, similar as for the first conductivity type semiconductor layer, the second conductivity type semiconductor layer may comprise a stack of an intrinsic semiconductor layer and a second type doped semiconductor layer, with materials selected as described above. Also, similar as for the first conductivity type semiconductor layer, between the surface of the semiconductor substrate 5 and the second conductivity type semiconductor layer, a thin tunnel barrier layer (not shown) may be arranged.
[0093] Additionally, the second conductivity type layer may also consist of a layer stack forming a MIS junction.
[0094] The second conductivity type is opposite to the first conductivity type. The first conductivity type semiconductor layer may constitute the emitter and the second conductivity type layer the BSF, or the first conductivity type layer may constitute the BSF and the second conductivity type layer the emitter.
[0095] In an embodiment, the first conductivity type is p-type and the first conductivity type semiconductor layer is p+a-Si:H, and the first dielectric layer is SiNx:H. Advantageously, the present invention provides that in this configuration the p-type a-Si:H layer is covered by the first dielectric. An exposed p-type a-Si:H layer when bare will degrade during deposition of a subsequent a-Si layer, basically due to thermal exposure. Covering with SiNx:H protects the p-type layer against such degradation, and therefore this invention allows a p-type emitter as first conductivity type semiconductor layer. It may be favorable to start with the p-type layer for cell efficiency reasons since this layer is generally the emitter which occupies generally the largest area on the rear surface.
[0096] Additionally, it may be favorable since the process of opening the first conductivity type layer can cause surface damage which diminishes the passivation properties of the layer deposited on the opened area.
[0097] FIG. 5 b shows a cross-section of a solar cell after a subsequent step as described above in FIG. 5 a , for an embodiment in which a tunnel barrier 10 a, 10 b is present either between the surface of the semiconductor substrate 5 and the patterned first conductivity type semiconductor layer 11 , or between the surface of the semiconductor substrate 5 and the patterned second conductivity type semiconductor layer 25 , or between the surface of the semiconductor substrate 5 and both the patterned first and second conductivity type semiconductor layers 11 , 25 .
[0098] Each of the tunnel barriers 10 a, 10 b under the first conductivity type semiconductor layer and second conductivity type semiconductor layer may be formed individually in separate processes. The tunnel barrier layer 10 a, 10 b may be grown by a surface reaction or may be deposited by a physical or chemical deposition process.
[0099] FIG. 6 shows a cross-section of a solar cell according to an embodiment of the invention, after a further step, in which a masking layer 30 is deposited over at least part of the first area portion A and the second area portion B. The masking layer may comprise a material selected from a group comprising silicon nitride (SiNx), silicon dioxide (SiO2), silicon-oxynitride (SiOxNy), a dielectric organic compound (a “resist” or resin), a dielectric metal oxide or dielectric metal nitride, and other suitable dielectrics. The masking layer may also be a metallic (e.g. contacting) layer.
[0100] Alternatively, the masking layer may be an intrinsic amorphous silicon layer, depending on the etching properties of the top layer deposited in the preceding process step.
[0101] Next a patterning step is carried out as shown in FIG. 7 . In the patterning step the masking layer 30 is patterned into a patterned mask 31 by removing the masking layer from a third area portion C of the stack of the patterned first dielectric layer 21 and the patterned first conductivity type semiconductor layer 11 .
[0102] Alternatively, the masking layer 30 may be deposited in a suitable pattern (pattern of layer 31 ), e.g. by deposition through a proximity mask, by deposition by a printing technique, etc.
[0103] The created third area portion C is smaller than the first area portion A, thus exposing a portion of the second conductivity type semiconductor layer above the stack of the patterned first dielectric layer 21 and the patterned first conductivity type semiconductor layer 11 . At the same time dielectric layer 31 covers a further portion of the second conductivity type semiconductor layer 25 that is in overlap with the stack of the patterned first dielectric layer 21 and the first conductivity type semiconductor layer 11 .
[0104] FIG. 8 shows a cross-section of a solar cell after a subsequent etching step, in which the exposed second conductivity type semiconductor layer 25 on the third area portion C is removed using the patterned mask 31 and a patterned second conductivity type semiconductor layer 26 is thus created. During this removal, the first conductivity type layer 11 is protected by the first dielectric layer 21 , which acts also as an etch-stop for this second removal.
[0105] Alternatively to deposition and patterning of layers 30 and 31 and etching of layer 25 , the second conductivity type semiconductor layer 25 may be removed on the third area portion C by a direct etching process, such as printing or (ink)jetting an etchant, or plasma etching through a proximity mask.
[0106] The solar cell structure now comprises the first area portion A where a first junction is arranged between the patterned first conductivity type semiconductor layer 11 and the substrate 5 and the second area portion B where a second junction is arranged between the patterned second conductivity type semiconductor layer 26 and the substrate 5 . Since on the surface of the semiconductor substrate, the first and second area portions A, B are adjacent to each other, the first and second junctions are also adjacent. In this manner the first and second junctions can be arranged in a closest approach. This bordering arrangement of the junctions provides a substantially complete coverage of the actively used substrate area for collecting charge carriers.
[0107] FIGS. 9 a -9 c show a cross-section of a solar cell according to a respective embodiment after a next step.
[0108] In this step, the patterned mask 31 or the patterned second conductivity type semiconductor layer 26 are functioning as a mask used for etching and removing the patterned first dielectric layer 21 in the third area portion C. Mask 31 may be absent in the case that, for example, layer 25 is locally removed by a direct etch process (as described above).
[0109] Layer 21 may also be locally removed (in third area portion C or a smaller area portion thereof) in a direct patterning step, e.g. by printing an etching paste ( FIG. 9 b ).
[0110] Layer 21 and 31 may also be locally removed by e.g. a wet-chemical etching step while e.g. protecting area D and some adjacent regions on area A and B by a dielectric etch mask, e.g. a deposited resist pattern 27 . The resulting structure will then differ from FIG. 9 a by having layer 21 extending some length into area A, and layer 31 being present on area D as well as extending some length into area B ( FIG. 9 c ).
[0111] The latter arrangement may be useful for improving long-term stability and improving electrical isolation in the final solar cell (resulting in FIG. 10 e ).
[0112] The patterned mask 31 , if present, may be removed in the same etching step that removes layer 21 (in case of comparable etching sensitivity and thickness of the first and second dielectric layer), or a further selective etching step.
[0113] After the etching step and the removal of the patterned mask 31 , the solar cell structure comprises the first area portion A where a first junction is arranged between the patterned first conductivity type semiconductor layer 11 and the substrate 5 and the second area portion B where a second unction is arranged between the patterned second conductivity type semiconductor layer 26 and the substrate 5 . Further the solar cell structure comprises an overlapping portion of the patterned second conductivity type semiconductor layer 26 that overlaps the patterned first conductivity type semiconductor layer. In an overlapping area D, the second conductivity type semiconductor layer 26 is separated and isolated by the patterned first dielectric layer 21 . In an example, the width of area D as indicated in FIGS. 9 a , 9 b , 9 c is between about 1 and about 1000 micron. In an alternative example the width of area D is between about 10 and about 500 micron. In yet another example the width of area D is between about 50 and about 250 micron.
[0114] Both the patterned first conductivity type semiconductor layer 11 in its first area portion A and the patterned second conductivity type semiconductor layer 26 in its second area portion B are in direct contact with the surface of the substrate over the respective full area portion (or are in contact with the tunnel barrier layer covering the surface of the substrate in case a tunnel barrier layer is present on the surface of the substrate) forming a first and second junction respectively.
[0115] Thus first conductivity type semiconductor layer 11 is substantially fully in contact with the substrate.
[0116] FIGS. 10-14 show some possible processes for metallization. Metallization may consist of the conductive layers introduced previously, and/or further conductive layers that (additionally) may be applied subsequently.
[0117] In FIGS. 10-14 entities with the same reference number as shown in preceding Figures refer to corresponding entities.
[0118] FIG. 10 a -10 e show cross-sections of the solar cell 1 after a metallization step. As shown in FIG. 10 a , on top of the patterned first conductivity type semiconductor layer 11 and the patterned second conductivity type semiconductor layer 26 a metallization layer (metallic conductive layer) 34 , 35 is deposited. FIGS. 10 b -10 e shows optional modifications of this step.
[0119] The metallization layer 34 , 35 is patterned by at least a gap 36 in the metallization layer to created electric isolation between a first portion 34 of the metallization layer over the first junction structure 5 , 11 and a second portion 35 of the metallization layer over the second junction structure 5 , 26 . The gap 36 is at least located above the overlapping portion of the second conductivity type semiconductor layer 26 , so that maximum coverage of metal on layer 11 and layer 26 is achieved, and minimum resistive loss, but may also extend further above portion A or B or both.
[0120] Extending the gap 36 from the overlapping portion to above either the first portion A or second portion B or both portions A, B may reduce the possibility for shunt, for example, if the dielectric 21 is not completely free of pinholes.
[0121] FIG. 10 e shows an embodiment where no areas of the patterned first and second conductivity type semiconductor layers 11 and 26 are directly exposed to atmospheric conditions. A dielectric layer 37 which could be the same as dielectric layer 27 as shown in FIG. 9 c covers an area of layer 26 adjacent to the overlapping area of the first and second semiconductor layers 11 , 26 . This arrangement may enhance durability of the performance of the solar cell. The metallization layers 34 , 35 may be deposited as blanket and subsequently patterned by etching, or it may be deposited in a pattern immediately.
[0122] The metallization layer may also consist of a first blanket deposition (e.g. a conductive oxide and/or a seed metal layer), followed by a patterned deposition of a second metallization layer (e.g. a (screen) printed or inkjetted silver pattern, or a resist pattern followed by (electro)plating), in turn followed by an etch back of the first blanket, using the second metallization pattern as a mask.
[0123] In an embodiment, the first blanket deposited layer may also be provided with a metal pattern by coating the first blanket layer with a dielectric layer such as silicon oxide, after which the dielectric layer is patterned and the conductive oxide is electroplated where it is free of the dielectric.
[0124] FIG. 11 a -11 c show a cross-section of a solar cell 2 according to a respective alternative embodiment. The single first conductivity type semiconductor layer is replaced by a first stacked layer that forms the first junction structure on the substrate and comprises the first conductivity type semiconductor layer 11 and the conductive layer 15 on top of it. The stacked arrangement is similar as shown in Figure lb.
[0125] The patterned second conductivity type semiconductor layer 26 is covered by a second conductive layer 40 and forms a second stacked layer. Preferably the second conductive layer is patterned in correspondence with the second conductivity type semiconductor layer 26 , for example by a process as described above with reference to FIG. 8 . In the embodiment as shown in FIG. 11 a , the gap 36 above the overlapping portion may be omitted.
[0126] The first stacked layer borders on the second stacked layer. The second stacked layer overlaps the first stacked layer in the overlapping region D. In the overlapping region D the first stacked layer is separated from the overlapping second stacked layer by an insulating dielectric layer 21 , in a similar manner as shown in FIGS. 5-8 .
[0127] In case the conductive layer 15 in the first junction structure is a conductive oxide, dielectric layer 21 may be replaced by an intrinsic amorphous semiconductor layer.
[0128] FIGS. 11 b and 11 c show an embodiment in which the gap 36 in the second conductive layer 40 extends over either the overlapping portion D or a part of the second area portion B.
[0129] The gap 36 in the second conductive layer 40 may be created around the overlapping portion of the second conductivity type semiconductor layer 26 to improve isolation from the conductive layer 15 in the first junction structure if needed.
[0130] It will be appreciated that as mentioned above various sloped forms of the overlapping portion D can be obtained, as indicated by the difference in slope of the overlap of the first and second conductivity type semiconductor layers in FIG. 11 a and FIGS. 11 b, 11 c.
[0131] FIG. 12 shows a cross-section of a solar cell according to an alternative embodiment after a manufacturing step.
[0132] In this embodiment, the first junction structure in the first area portion A comprises a stack of the first conductivity type semiconductor layer 11 and the conductive layer 15 on top of it. The stack of the first conductivity type semiconductor layer 11 and the conductive layer 15 is patterned and covered by a patterned dielectric layer 22 .
[0133] Covering the patterned stack of the first conductivity type semiconductor layer 11 , the conductive layer 15 and the dielectric layer 22 , is the second conductivity type semiconductor layer 25 . In the second junction structure in the second area portion B a stack of a patterned second conductive layer 45 and a second masking layer 50 is arranged, with the second masking layer on top of the second conductive layer 45 .
[0134] To obtain the structure as shown in FIG. 12 , both the second conductive layer 45 and the second masking layer 50 are deposited over at least the second area portion B. Next the second masking layer 50 is patterned. The patterned second masking layer 50 is then used to define the location of the patterned second conductive layer 45 in the second area portion B. An optional spacing S between the end E of the patterned second conductive layer 45 and the boundary F of the first area portion A and the second area portion B is created to improve isolation.
[0135] FIG. 13 shows a cross-section of the solar cell of FIG. 12 after a next step according to an embodiment wherein the second masking layer 50 is selectively removed. It will be appreciated that removal of the second masking layer 50 may be optional, since a contact to the second conductive layer 45 may be achieved through the second masking layer 50 e.g., by mechanical force.
[0136] FIG. 14 shows a cross-section of the solar cell 3 of FIG. 13 after a subsequent manufacturing step. In the subsequent step, a dielectric, e.g. a resist layer is deposited over the structure as shown in FIG. 13 . Next, if the dielectric layer was not deposited in a pattern, the dielectric layer is patterned to create a protective dielectric, e.g. a resist, body 55 that covers the overlapping portion of the second conductivity type semiconductor layer and the boundary region E-F between the first and second area portions A, B.
[0137] The patterned protective dielectric body is used as a mask to etch/remove a portion of the second conductivity type semiconductor layer 25 and of the dielectric layer 22 using the conductive layer 15 and the second conductive layer 45 as etch stop layers, in a manner that the overlapping portion of the second conductivity type semiconductor layer overlaps the stack of the patterned conductive layer 15 and the patterned first conductivity type semiconductor layer 11 . The first dielectric layer 21 acts as a separating layer.
[0138] The protective dielectric body 55 can be used in a subsequent plating step (e.g. an electroplating step) to separate a metal contact on the first area portion A from a metal contact on the second area portion B. The protective dielectric body 55 can also provide durability of the performance of the solar cell, by protecting the layer 26 which may be very thin and susceptible to atmospheric conditions penetrating a solar module.
[0139] The skilled in the art will appreciate that the protective dielectric body can be applied in other embodiments such as for example the embodiment shown in FIG. 10 e.
[0140] It will be apparent to the person skilled in the art that other embodiments of the invention can be conceived and reduced to practice without departing from the true spirit of the invention, the scope of the invention being limited only by the appended claims. The above described embodiments are intended to illustrate rather than to limit the invention. | A solar cell including a semiconductor substrate, having a front side surface for receiving radiation and back-side surface providing a first junction structure in a first area substrate portion and with a second junction structure in a second area substrate portion. The second area portion borders the first area portion. The first junction structure includes a first conductivity type semiconductor layer covering the first area portion. The second junction structure includes a second conductivity type semiconductor layer covering the second area portion. The second junction structure, second conductivity type semiconductor layer partially overlaps the first junction structure, first conductivity type semiconductor layer, with the overlapping second conductivity type semiconductor layer portion being above a first conductivity type semiconductor layer portion while separated by a first dielectric layer. The first conductivity type semiconductor layer portion under the overlapping second conductivity type semiconductor layer portion directly contacts the semiconductor substrate surface. | 7 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not applicable.)
BACKGROUND OF THE INVENTION
Organic excreta, whether from domestic, stray or wild animals, often has a substantial adverse impact on otherwise pleasant modem lifestyles. The same also represents a significant health threat, due to the plethora of diseases often found in animal excrement. While nature will, over time, degrade the organic components of excreta, such action is relatively very long-term. Moreover, while the same is occurring, excreta poses a health hazard, gives off unpleasant odors, and appears and is repulsive to most individuals. At the same time, solid excreta also present the possibility of being picked up underfoot and spread, sometimes even into the home, office or commercial environment. Finally, excreta while it is deteriorating naturally over a long period of time tends to damage lawns due to heat and other prolonged effects.
In an effort to avoid the dangers and unpleasantness associated with the same, numerous jurisdictions have implemented so-called “pooper scooper” laws which require, for example, a dog owner to clean up after a pet, for example, while it is being given its required daily walk. However, in addition to the fact that pet owners are not all fastidious about cleaning up after their animals, numerous sources of excreta, not controllable by pooper scooper regulations abound. These range from problems created by Canadian geese on golf courses and waterfront properties to the excreta of wild deer beside houses in the suburbs, and leavings of stray animals in urban locations.
SUMMARY OF THE INVENTION
While the above-mentioned action of nature integrating organic waste can be accelerated by the addition of bacterial agents, such as known bacterial spores, which in the presence of moisture and nutrition will emerge from the dormant state to an active bacterial phase to degrade the organic waste, in accordance with the present invention, the applicant herein has noted that prior approaches such as the collection of excreta and consolidation into a lagoon or other container, where the bacterial agent may be combined with the organic excreta, which one wishes to dispose, do little to remove the unpleasantness associated with the treatment of such materials.
Typically, such techniques only make sense in the case of large amounts of excrement such as would be found, for example, on a livestock farm, or other similar facility. The large amount of material involved makes it possible to use mechanized equipment to quickly and effectively move a large amount of material into a central area where the same can be efficiently treated. However, such an approach does not make sense in the case of the relatively low volume and low-density of animal excreta typically associated with residential non-farming animal excreta problems. Moreover, consumers do not usually have available to them a place where such bacterial degradation can be done. It is further, in accordance with the present invention, noted that, even in the event that a consumer wished to devote an area of his garden to the treatment of excreta, the concentration of excreta in a single place during the treatment of the excreta will result in one area for culturing disease and emitting smell.
Perhaps even more inconvenient is the fact that the same is a relatively complex process to implement, involving collection of excreta, transporting the same to a central area, loading the same into that area, and, finally, applying the material to accelerate organic degradation of the excreta.
The present invention has as its object a simple convenient process for dealing with animal excreta. The same is achieved without collection or transport of the excreta or even contact with the same, while at the same time greatly reducing the possibility of the same being spread either outside a building or into a structure. In accordance with the invention, the excreta are dispatched in an essentially one step process that is both environmentally friendly, convenient and relatively pleasant to implement.
More particularly, in accordance with the invention, excreta are dispatched through the use of an off-the-shelf appliance which may conveniently and unoffensively be stored in any location, from which it may be retrieved with a minimum of effort, used and replaced. At the same time, the appliance remains completely clean and pleasant to handle.
Bioaugmentation is the practice of enhancing the performance of indigenous microorganism populations of wastewater treatment systems through the addition of microorganism cultures with specific degradative abilities. This bioaugmentation improves the efficiency of the already present process of degradation of wastewater products by indigenous microorganisms. The microorganisms used for this process are selected to enhance microbial populations of an operating waste treatment facility to improve water quality and/or lower operation costs. Factors used in selecting the microorganisms, typically bacteria and fungi, include reproduction rates and ability of the microorganisms to perform specific functions in the degradation process. The bioaugmentative microorganism are sold as liquid or dried on a bran carrier.
Further, bioremediation is the use of selected microorganisms to accomplish a biological cleanup of a specified contaminated area, such as soil or water. This is performed for a finite project or area, not an ongoing process, such as bioaugmentation.
BRIEF DESCRIPTION OF THE DRAWINGS
One or more embodiments of the invention and of making and using the invention, as well as the best mode contemplated of carrying out the invention, are described in detail below, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a front view of an embodiment of a spray bottle to be used in accordance with the present invention;
FIG. 2 is a front view of an embodiment of a sprinkle bottle for dry powder to be used in accordance with the present invention;
FIG. 3 is a front view of an embodiment of a pump bottle to be used in accordance with the present invention;
FIG. 4 is a front view of an embodiment of a garden sprayer of the type that a user can pressurize the tank such that the liquid contained within the tank can be sprayed using that force, said garden sprayer to be used in accordance with the present invention;
FIG. 5 is a front view of an embodiment of a pressurized spray gun of a type commonly used by children in play, a user can pressurize an air bladder such that the liquid contained within a tank can be sprayed using the force from the air bladder and sprayed for long distances, said spray gun to be used in accordance with the present invention;
FIG. 6 is a front view of an embodiment of an aerosol spray can to be used in accordance with the present invention;
FIG. 7 is a front view of an embodiment of a liquid sprinkle bottle to be used in accordance with the present invention; and
FIG. 8 illustrates a top view of the sprinkle head of the sprinkle bottle of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , in accordance with the invention, a waste degradation accelerator 10 contained in an applicator appliance 12 promotes the rapid breakdown of organic matter such as dog feces and other animal excreta. Such organic matter includes, even slow to degrade material within the feces, in an environmentally friendly manner. In the preferred embodiment, accelerator 10 is a liquid, made of organic materials that accelerates the natural degradation cycle of fecal wastes. In addition, the end products of the breaking of these wastes down are beneficial soil nutrients, that are essential for turf grass and plant growth. Further, accelerator 10 breaks the nutrients down into a form that is easily assimilated by the root system.
As will disclosed in more detail, the fecal waste is broken down into sugars, amino acids, and other nutrients such as calcium. The nutrients serve to nourish the soil on which the feces are sitting, and also are utilized by the fecal degrading bacteria present in accelerator 10 to increase the growth rate of the bacteria. The bacteria consume the organic compounds present in the fecal matter and convert them into carbon dioxide, water, nitrogen, potassium, phosphorus, and calcium, especially in the form of calcium carbonate and cellular energy in the form of adenosine triphosphate (ATP) and other related compounds, which foster reproduction of the bacteria, and at the same time, the inventive process changes odor producing substances to non-odor producing products, such as water, carbon dioxide and salts. Further, the bacteria present in accelerator 10 can also potentially compete with pathogens to attenuate their pathogenicity.
Accelerator 10 comprises a bacterial and enzyme formula suspended in a water carrier. A preservative such as ethylenediaminetetraacetic acid(“EDTA”) or germicide, such as a nipocide is added. The preservative serves to keep the intended bacteria of the product in a dormant, spore state, thus preventing germination, and prevent airborne bacteria from contaminating the solution. The amount of preservative used is the product of a delicate balance. Enough should be used to inhibit germination and contamination, but not so much as to kill the intended bacteria. Water makes up about 90% of the inventive accelerator 10 .
The bacteria of accelerator 10 is of the bacillus variety. An accelerator material of the type supplied to the inventor herein by Apptec Inc., 4 Washington Drive, Cranbury, NJ 08512 is preferred. This accelerator 10 has a count of 54 billion bacteria per milliliter of accelerator 10 or 1.56 billion per ounce. A blend of bacilli of the thermophilic variety are used. Thermophilic bacteria grow best at high temperatures. Further, the bacilli are aerobic (use oxygen) and facultative anaerobic (aerobic bacteria that can also function, at least for a limited time, with little or no oxygen). The bacilli used are chosen for their extracellular enzyme activities. More specifically, the bacilli have cellulase, protease, lipase, and amylase activity to break down cellulose, proteins, fats and starches.
Aerobic bacteria, bacilli in the present invention, consume nutritionally 15 to 30 parts carbon for each part nitrogen. The preferred embodiment of the present invention works best with a carbon/nitrogen ratio of 30 or less, which, under normal circumstances is the natural ratio in most animal feces. This ratio being favorable for rapid degradation of the fecal matter.
Further, the bacilli of the present invention are spore forming. This allows the dormant spore bacterial colonies in the applicator 12 to withstand unfavorable conditions of heat, cold, pH, and certain chemicals, providing a long shelf life for the products. For example, containing such spores in the wild or in certain countries before consuming water, Water must be boiled for at least 5-10 minutes. Anything less might allow spore forming bacteria to survive.
The other major component of accelerator 10 is a quantity of free enzymes which serve to start the breakdown process of the feces. More specifically, these enzymes include: proteases, amylases, cellulases and lipases.
Protease breaks down proteins into peptides (short chains of amino acids) and free amino acids. These peptides and free amino acids serve as a nitrogen sources for the bacteria to foster the feces degradation.
Acceleration 10 comprises ingredients from a class of enzymes known as amylases which hydrolyze starchy materials into glycogen and disaccharides. Cellulases are also included in acceleration 10 to break down cellulose, a complex carbohydrate and the main structural component of cell wall material, into its shorter poly- and monosaccharides constituents, making them more bio-available to the bacteria and the soil. The final class of enzymes used as ingredients for acceleration 10 are the lipases which break down fats into fatty acids and glycerols.
A surfactant may also be included in accelerator 10 . The surfactant serves to reduce the surface tension of the substrate, which in this case is the feces, causing it to emulsify, break into smaller particles with less adhesion between the particles. This emulsification makes the feces more bio-available to the bacteria, by allowing its particles to pass through the cell wall of the bacilli, so the bacilli can digest it.
Accelerator 10 is made of a mixture of approximately 10% bacteria, free enzymes, surfactant, fragrance, dyes and inert ingredients and approximately 90% water. This combination has a specific gravity of about 1.05, and a cloudy dark amber colored appearence. Accelerator 10 has a boiling point of approximately 100° C. and a freezing point of −1° C. Accelerator 10 has a pH of approximately 7.
The biologic activity of accelerator 10 , although very stable, can be affected by prolonged exposure to adverse temperature and pH. The preferred embodiment of accelerator 10 functions best in a temperature range of 3.33° C. to 62.8° C. (38° F. to 145° F.). Temperatures above 63° C. have been shown to inactivate the biologic cultures used in accelerator 10 . The functional pH range for accelerator 10 is 5 to 9.8.
Very strong acids and bases can deactivate the biologic cultures. Accelerator 10 has not been shown to be sensitive to light.
These broad ranges of temperature and pH are made possible by the spore status of the bacilli. This leads to a shelf life of accelerator 10 of approximately two years when kept in a cool, dry place. The preferred embodiment is best stored at 1.7° C. to 95° C. (35° F. to 95° F.).
Accelerator 10 is environmentally friendly. All of the ingredients of accelerator 10 are biodegradable and nontoxic, making it safe for use around plants, animals, humans. Accelerator 10 has been shown not to harm aquatic life, so it can be used near bodies of water. Further, as accelerator 10 breaks down the feces, it does not produce any air polluting volatile organic compounds (VOC's).
Despite the environmental friendliness of accelerator 10 , it can cause eye and skin irritation with contact. Therefore, eye protection is recommended to be worn by the user. Should eye or skin contact occur, the user should wash the skin with ordinary soap and water, and should flush his eyes with water for fifteen minutes.
Although accelerator 10 does produce skin irritation, not enough is absorbed through skin to result in any toxic effect. If accelerator 10 is ingested, it can cause some abdominal pain, nausea and vomiting, although most of the types of constituents of accelerator 10 are present in the human gastrointestinal tract. Accelerator 10 is not a known inhalation hazard, but inhalation should be avoided nonetheless. Accelerator 10 is safe enough to use in a normally ventilated room.
In the preferred embodiment, accelerator 10 will be supplied from a applicator 12 , such as a common spray bottle, as is illustrated in FIG. 1 . In the preferred embodiment, the spray bottle 12 may be opaque to hide the unattractive dark amber color. Spray bottle 12 is made of a vessel 14 , attached to vessel 14 . Attached to vessel 14 is a sprayer head 16 . Sprayer head 16 is attached to vessel 14 by any means common in the art, such as threading. Sprayer head 16 has a nozzle portion 18 and a trigger portion 20 . When trigger portion 20 is squeezed, accelerator 10 is dispensed through nozzle 18 .
The spraying action of accelerator 10 forms the accelerator into a jet 21 which may be as long as one, two or three meters long, or longer by applying substantial force to liquid accelerator 10 , giving it considerable momentum when the jet of accelerator impacts on the feces, this provides for a mechanical breakdown of the feces, assisting the surfactants in the emulsification of the feces, making it more bio-available to the bacteria by breaking larger chunks into smaller ones and increasing the surface area of the feces for increased bio-activity. The use of a long jet allows the user to apply the material while standing at a relatively remote point from the feces to be dispatched.
After spraying, the free enzymes are the first to act after the surfactants on the feces. As the enzymes break down their respective targeted components and to a lesser extent other components, this provides food for the bacteria. When ample food and water are present, the bacilli come out of the spore state and begin to germinate and feed on the feces nutrients. With the continued action of the surfactant, free enzymes, bacteria and enzymes produced by the bacteria, the feces is broken down, and the nutrients are returned to the soil.
In a petri dish and on turf grass, under ideal conditions of temperature, humidity and light, accelerator 10 will increase degradation time from approximately 10 to 15 days to 3 to 4 days, with emulsification occurring within approximately 24 hours. Additionally, accelerator 10 will provide nutrients from the feces to the turf grass which in turn strengthens the grass by increasing its root mass.
In use, the user keeps the inventive spray bottle 12 on the shelf or in another convenient place and transports it to the location where it is to be used. At that location sprayer head 16 is aimed at feces to be dispatched and squeezes the trigger 20 to send a quantity of accelerator to the feces.
In an alternative embodiment of accelerator 10 , nitrogen can be added to the mixture. In the preferred embodiment, the nitrogen source is urea, which turns the mixture a dark brown. The nitrogen prevents nitrogen depletion of the bacilli from limiting the degradation rate of the fecal matter. Under conditions where nitrogen is depleted, such as with nitrogen deficient soil, or under composting conditions, applications addition of nitrogen is desirable. Further, the addition of nitrogen helps further support the root structure of the vegetation under and around where the feces is deposited.
In another alternative embodiment of the present invention, an odor eliminating compound can be added to accelerator 10 . This odor eliminating compound can be of a type that is zinc based, or a material in the odor neutralizing class. The zinc based odor eliminating compounds form a molecular cage around the odor forming component of the feces, reducing or substantially eliminating the inherent smell of the matter. Although zinc can have an inhibitory effect on bacteria, in the present embodiment, the zinc compounds are used in very low doses which have been shown not to have adverse effect on the bio-activity of accelerator 10 .
One may also apply odor neutralizing compounds, such as the one sold by Apptec under the name N100, in accelerator 10 to convert a compound to an odorless salt, thus eliminating the odor of the matter.
In another alternative embodiment of the present invention, an odor masking component can be added to accelerator 10 . The surfactants of accelerator 10 serve to suspend the odor masking component in solution. These odor masking components can be from a mixture of natural or synthetic fragrant oils or extracts or mixtures thereof, producing a pleasant aroma, such as fresh scent, or herbal scent.
In a further alternative embodiment, dye or pigments can be added to accelerator 10 .
When accelerator 10 is sprayed, it marks the feces with a visible color or white so people do not step in the feces during the inventive degradation process. Additionally, a photo-luminescent dye can be used to make the degrading feces visible under low light conditions. Since the dye or pigment relies on the structured integrity of the feces, when the dye or pigment is not visible, the feces is substantially totally degraded.
In yet another alternative embodiment, accelerator 110 can be dehydrated forming a powder that can be sprinkled using a sprinkle bottle 112 on the feces. The natural moisture of the feces reconstitutes the accelerator, making it bio-active. If the feces is dehydrated, it may be beneficial to spray water on the feces with the application of the dehydrated accelerator 10 . Sprinkle bottle 112 is generally comprised of a vessel portion 114 and a sprinkling head 116 . Sprinkling head 116 containing multiple holes to allow accelerator 110 to flow through Further, rotation of head 116 on vessel 114 will cause holes 118 to open and close.
Additionally, the dehydrated accelerator 10 can be sold in a powder form, and reconstituted by the user in their home. For example, the user may add the dehydrated accelerator 10 to a spray bottle, then add a defined amount of water, reconstituting the accelerator, and making it ready for use.
Alternatively, accelerator 10 can be distributed in an pump bottle 212 . In the present embodiment, the pump bottle 212 is optionally opaque to hide the unpleasant dark amber color. Pump bottle 212 is made of a vessel 214 . Attached to vessel 214 is a sprayer head 216 . Sprayer head 216 has a nozzle portion 218 . When head 216 is pressed toward vessel 214 , accelerator 10 is dispensed through nozzle 218 .
Alternatively, accelerator 10 can be distributed in a garden sprayer 312 , as is illustrated in FIG. 4 . In the present embodiment, the garden sprayer 312 is optionally opaque to hide the unpleasant dark amber color. Garden sprayer bottle 312 is made of a vessel 314 , attached to vessel 314 is a sprayer head 316 . Sprayer head 316 is attached to vessel 314 by way of a hose 322 . Sprayer head 316 has a nozzle portion and a trigger portion 320 . Vessel 314 has a pump handle 324 attached. As pump handle 324 is moved toward and away from vessel 314 , air is pumped into vessel 314 creating pressure. When trigger portion 320 is squeezed, accelerator 310 is dispensed through nozzle 318 using the pressure created by handle 324 .
Alternatively, accelerator 10 can be distributed in a high pressure pump sprayer 412 , such as those played with by children and sold under the trademark SUPER SOAKER. Pump sprayer 412 is made of a vessel 414 which holds accelerator 10 . As a user would move pump handle 424 back and forth, pressure is created in an air bladder 428 . When trigger 420 is squeezed, accelerator 410 is dispensed through nozzle 418 using the pressure from bladder 428 . This is useful when the user needs to spray at a distance. Such an application is that of a farmer spraying onto a pile of feces, while the farmer is on his tractor.
Alternatively, accelerator 10 can be distributed in an aerosol bottle 512 , as is illustrated in FIG. 6 . In the present embodiment, the aerosol bottle 512 is optionally opaque to hide the unpleasant dark amber color. Aerosol bottle 512 is made of a vessel 514 , attached to vessel 14 is a sprayer head 516 . Sprayer head 516 is attached to vessel 514 by any means common in the art Sprayer head 516 has a nozzle portion 518 . When head 516 is pressed toward vessel 514 , accelerator 510 is dispensed through nozzle 518 , using the force generated by a propellant added to vessel 514 at the time of manufacture.
Alternatively, a liquid accelerator 10 can be distributed in a sprinkle bottle 612 as is illustrated in FIG. 7 . In the present embodiment, the sprinkle bottle 612 is optionally opaque to hide the unpleasant dark amber color. Sprinkle bottle 612 is made of a vessel 614 . Attached to vessel 614 is a sprinkle head 616 . Sprinkle head 616 is attached to vessel 614 by any means common in the art. Sprinkle head 616 has a hole portion 618 . When a user shakes the sprinkle bottle 612 , accelerator 10 is dispensed through hole portion 618 .
It is further conceived that dispensers of the inventive accelerator can be sold in vending machine in areas where dogs are commonly walked, such as city parks.
In the description, reference is made to the accompanying drawings, which form a part hereof, and which illustrate examples of the invention. Such examples, however, are not exhaustive of the various embodiments of the invention, and therefore, reference is made to the claims which follow the description for determining the scope of the invention. While illustrative embodiments of the invention has been described, it is, of course, understood that various modifications of the invention will be obvious to those of ordinary skill in the art. Such modifications are within the spirit and scope of the invention which is limited and defined only by the appended claims. | An appliance for accelerating the degradation of feces and other organic wastes is disclosed. The appliance comprises a container containing an accelerator to accelerate the breakdown of fecal wastes, and a transport mechanism for ejecting the accelerator from the container. The accelerator comprises a mixture of microorganism and free enzymes which are environmentally friendly and non-toxic. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method for controlling grease injection to a subsea intervention system and an apparatus comprising a housing containing a control unit and a pump for grease.
[0003] 2. Description of the Related Art
[0004] When performing intervention in a hydrocarbon well, it is necessary to isolate the well from the environment. Intervention is often carried out using wireline techniques (braided wire, composite cable or slickline). To contain the pressure in the well during operations and avoid hydrocarbons escaping to the environment, intervention operations involve the use of a stuffing box which is part of a pressure control head (PCH). The PCH provides a dynamic seal between the cable and the wellbore enclosures to maintain pressure control and prevent wellbore fluids from leaking into the environment. However, because of its braided (wire rope like) exterior, the cable has a bumpy, crevice-filled surface which is difficult for the PCH to seal around as the cable passes through the PCH as it travels into and out of the well.
[0005] FIG. 1 is a schematic drawing showing a prior art subsea lubricator system 100 attached to a subsea well 105 . The subsea well 1055 extends into a subterranean formation and has a Christmas tree 106 attached to the wellhead and a flowline/umbilical 107 extending to a process facility. The subsea lubricator stack 100 includes a pressure control unit (BOP) 111 , a lubricator (pipe) 112 and the pressure control head (PCH) 113 .
[0006] The lubricator system 100 further comprises a control system (IWOCS) 115 with a separate workover umbilical 117 extending to the surface. The control system 115 controls the system 100 . In prior art operations, grease is pumped down the line 117 and further through line 123 to the PCH 113 to maintain a seal between the braided wire or cable 109 and the seawater environment.
[0007] Current practice is to inject grease into the PCH body 113 at a higher pressure than that of the well. In addition, grease has to be replenished at some rate to replace grease lost to the surface of the braided cable 109 as it passes through the ends of PCH 113 (going into or out of the well). The grease injection rate is controlled by periodic visual monitoring of the sealing ends of the PCH 113 for leakage and monitoring the grease injection pressure.
[0008] This operation gets complicated when performing this practice subsea on a subsea well. This involves the use of a subsea riserless light well intervention (RLWI) stack. For RLWI, the PCH 113 is now remote and difficult to monitor; making it difficult to determine when and how much grease needs to be injected. Furthermore, as the stack is run in deeper water, the length of the grease supply line feeding the PCH 113 grows longer, making it increasingly difficult to pump viscous grease down to the PCH 113 at a reasonable surface pressure or pump rate. The long grease lines and viscous grease becomes more problematic as deeper colder environments are encountered. To do that requires pumping grease at some empirical rate monitored visually. In subsea situations, the pumping pressure is exacerbated by the length of the grease line going down to the subsea PCH 113 and the rate is often a pure guess, often resulting in sending too much grease down to conservatively compensate for the unknown conditions.
[0009] Current practice for subsea grease injection requires the surface deployment of grease lines as shown in U.S. Pat. No. 4,821,799, which is hereby incorporated by reference in its entirety. That patent discloses the use of an accumulator to enable a better control of injection pressures.
[0010] There is also a more subtle problem associated with grease injection to a subsea PCH 113 , namely, water ingress. Normally, the PCH 113 is lowered to the lubricator tube 112 together with the tool. However, in some operations, the PCH 113 is run independently after the wireline tools, cable, etc. are landed in the RLWI stack's lubricator tube 112 . As the PCH assembly is lowered down to the sea floor, the braided cable 109 passes through the PCH 113 . If grease is not supplied at a sufficient pressure and rate to offset the increase in ambient seawater pressure, and the loss of grease to the cable 109 passing by, seawater could weep past the seal ends of the PCH 113 into the main cavity of the PCH 113 and/or the tube 112 . If this occurs, there is an increased risk that the water will help to form a hydrate plug inside the PCH 113 (later exposed to wellbore pressure and fluids) and prevent the cable 109 from freely moving through the PCH 113 .
[0011] The present invention is directed to methods and devices solving, or at least reducing the effects of, some or all of the aforementioned problems.
SUMMARY OF THE INVENTION
[0012] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
[0013] The present subject matter is generally directed to a method and a device for controlling grease injection to a subsea intervention system, where there is provided an at site pressure compensated system for providing the grease at a pressure higher than the outside pressure, this being either the well pressure, the pressure of the water around the subsea system, outside pressure, or both of these pressures.
[0014] According to one aspect, the present subject matter may be employed in an intervention workover control system (IWOCS) that is all electric or electro-hydraulic that may comprise a processor with the capability to handle information, for example, to record outside ambient seawater pressure, pressure inside the PCH and below the PCH (inside the well). As mentioned above, the purpose of the grease and PCH is to create a dynamic seal that generates a slightly higher (grease) pressure inside the PCH than the pressure of the environment above the PCH or the pressure in the well below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
[0016] FIG. 1 is a schematic depiction of an illustrative prior art subsea lubricator system;
[0017] FIG. 2 shows a sketch of an intervention system on a subsea well;
[0018] FIG. 3 is a diagram showing the grease injection module in IWOCS mode; and
[0019] FIG. 4 is a diagram showing the grease injection module in autonomous mode.
[0020] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Illustrative embodiments of the present subject matter are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0022] The present subject matter will now be described with reference to the attached figures. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
[0023] FIG. 2 is a schematic drawing showing a subsea lubricator system 10 described herein attached to a subsea well 5 . The subsea well 5 extends into a subterranean formation and has a Christmas tree 6 attached to the wellhead and a flowline/umbilical 7 extending to a process facility. The subsea lubricator stack 10 includes a pressure control unit (BOP) 11 , a lubricator (pipe) 12 and the pressure control head (PCH) 13 .
[0024] The lubricator system 10 further comprises a control system (IWOCS) 15 that controls the system 10 . Electrical power is supplied to the control system by electrical power line 17 . In one illustrative embodiment, a grease injection module 21 is attached to the PCH 13 . An electric cable 23 connects the grease injection module 21 with the control system 15 . With the grease injection module 21 attached to the PCH 13 , it can be raised and lowered together with the PCH 13 and operate in an autonomous mode. In another embodiment, the grease injection module 21 is not attached to the PCH 13 , but rather is made as a part of the control system 15 . In that case, an additional fluid line 25 (shown as a dashed line) is employed to supply grease or lubricant to the PCH 13 . In some embodiments, a single line from the control system 15 to the grease injection module 21 may contain both electrical and fluid lines.
[0025] The subject matter disclosed herein proposes the elimination of a grease line (like the grease line 117 shown in FIG. 1 ) to or from the surface to supply lubricant to the PCH 13 . In one embodiment, as shown in FIG. 3 , lubricant may be supplied to the PCH 13 by use of a depth compensated accumulator 31 filled with a lubricant or grease. The grease injection module 21 comprises an accumulator 31 for grease operatively connected via line 33 to a pump 35 . The outlet grease line 37 from the pump 35 is connected to the PCH 13 . The pump 35 is controlled by an electric motor 36 . A first power supply cable 32 connects the control system 15 with the electric motor 36 for the pump 35 . The grease line 37 has a one way valve 43 , a shut-off valve 44 and a pressure and temperature sensor 45 .
[0026] In the embodiment shown in FIG. 3 , there is also provided a second pump 38 with associated motor 39 , having a separate power supply cable 34 . A second grease line 41 connects the pump 38 with the PCH 13 . As above, the second grease line 41 includes a one way valve 46 , a shut-off valve 47 and a pressure and temperature transmitter 48 . The second pump 38 may be added to provide for redundancy in the system, in case of failure of the first pump 35 . Providing dual pumps 35 , 38 also makes it possible to generate higher grease pumping rates in case of emergency, with both pumps operating together. They may also be used for the rare times when the cable 9 is travelling very quickly through the PCH 13 and may require more grease than one electric motor/pump can supply.
[0027] As an alternative, grease may be wiped from the cable 9 as it passes out of the PCH 13 and returned to a container in the grease injector module 21 . For example, as shown in FIG. 3 , a return grease line 52 that is in fluid communication with a canister 54 may be provided. In this way, very little, if any, grease will be released to the environment.
[0028] In addition, an ROV attachment 22 may be added to provide a means to periodically replenish the grease in the accumulator 31 for long duration jobs.
[0029] In operation, the control system 15 closely monitors the pressure of the environment outside of the PCH 13 , the pressure inside the PCH 13 and/or the pressure in the well 5 . Periodically, the control system 15 actuates one or both (depending upon the situation) of the grease pumps 35 , 38 to pump grease into the PCH 13 . The grease pressure is closely monitored and the pump(s) 35 and/or 38 are regulated to generate a very small pressure differential between the PCH 13 and the well 10 , e.g., a differential of approximately 15 psi. Stated another way, the grease is injected at a pressure that is a set or established value above at least one of the monitored pressures.
[0030] The close in-situ monitoring of the various pressures by the control system 15 minimizes the amount of grease or lubricant needed because the differential pressure can be kept to a minimum value, e.g., a 15 psi differential pressure. A lower differential pressure or set value may also be employed. This is a significant benefit as compared to prior art systems where operators merely guessed as to the volume of grease needed, and the associated difficulties trying to pump the grease down a grease line. Keeping the differential pressure or set value to a minimum also lessens the amount of grease that works itself past the seal elements (not shown) in the PCH 13 into the well and/or the environment. By employing two pumps 35 and 38 , the grease may be injected into the PCH 13 in two locations (again opening one or two lines to compensate for situations of high cable speed, rapid loss of grease, etc.). There also may be a third grease injection line 51 in a location below the PCH 13 for better control of the differential pressure between the PCH 13 and the well, if necessary.
[0031] In the embodiment shown in FIG. 4 , the grease injection module 21 is equipped with its own separate control unit 60 configured as an autonomous version of the control system 15 . The autonomous control unit 60 comprises a processor and data storage (not shown) and is preferably powered by a battery 62 . Thus, the electric control can be separated from the main control system 15 , while retaining the monitoring and injection control features for grease injection into the PCH 13 . This embodiment simplifies the packaging of the PCH 13 assembly by eliminating the need for the subsea electrical connection 23 ( FIG. 2 ) after the PCH 13 is lowered separately and latched to the rest of the intervention (RLWI) stack. However, this autonomous feature adds two new capabilities. First, as the PCH 13 assembly is lowered to the sea floor, it independently monitors the increase in ambient seawater pressure and can adjust by injecting grease into the PCH 13 at just a slightly higher than ambient pressure differential, e.g., a 15 psi differential, to keep seawater from entering the cavity in the PCH 13 , thereby avoiding the hydrate plugging issues. The control unit 60 is battery powered to maintain its autonomy. Second, in the event that the surface vessel needs to depart and/or the cable is cut somewhere outside of the PCH 13 and the control system 15 is disconnected, the grease injection pressure containment feature of the PCH 13 is maintained even though the rest of the control system 15 is shut down, for as long as battery power is present.
[0032] Another issue is the grease itself. Current practice is to use some form of viscous petroleum based grease that has a certain amount of stickiness to adhere to the surface of the seals (not shown) in the PCH 13 and the rough exterior of the cable 9 , creating a pseudo smooth surface on the braided cable. However, this creates its own “leakage to the environment” as the grease laden cable 9 emerges out the top of the PCH 13 during wireline retrieval. In addition, the ambient seawater environment may be as low as 4° C. (39° F.), which may lead to an increase in the grease's viscosity or lead to a hardening condition. To alleviate this condition, it is contemplated to replace petroleum grease with a bio-degradable, non-hydrocarbon lubricant, such as a fish oil based lubricant, e.g., cod liver oil, so as to significantly lower the viscosity of the lubricant and eliminate hydrocarbon discharge to the environment.
[0033] The benefit of the present invention is that its architecture is substantially depth insensitive, eliminating the pressure flow rate problems associated with pumping viscous grease longer distances (at higher surface pump pressures) and eliminates waste by using environmentally friendly lubricants that are injected at much lower differential pressures because the injection process is monitored. It also eliminates a line going into the water which is beneficial for better line management; critical for deepwater (>500 m˜1500 ft.) operations.
[0034] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. | A subsea lubricator system is disclosed which includes a lubricator tube adapted to be positioned subsea above a subsea well, a pressure control head adapted to be positioned above the lubricator tube, at least one pressure sensor adapted for sensing at least one of a pressure in the subsea well or an ambient seawater pressure proximate the pressure control head, and at least one pump that is adapted to be positioned subsea to inject a lubricant into the pressure control head at a pressure that is greater than the sensed pressure. A method of operating a subsea lubricator system positioned above a subsea well, the lubricator system including a pressure control head, is also disclosed which includes monitoring at least one of a pressure within the well and an ambient seawater pressure proximate the lubricator system, and injecting a lubricant into the pressure control head at a pressure that is greater than the monitored pressure. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage of PCT/DE 95/01816 filed Dec. 14, 1995 and based upon German national application P44 45 700.6 on Dec. 21, 1994 under the International Convention.
This invention relates to pipe fittings made of weldable plastic material. More particularly it relates to a hot-tap fitting for connecting a branch pipe to a main pipeline, wherein the fitting facilitates temporary connection of a standard hot-tap tool to the main plastic pipeline, followed after tapping, by permanent connection of the branch-pipe to the main pipe at full pressure rating.
BACKGROUND OF THE INVENTION
The need to add new customer service branch pipes to existing main gas or water utility pipelines has long been recognized. The safest method is to isolate the section of main pipeline, depressurize, purge, cut a hole, clean out, and permanently attach a tee adapter to which the branch pipe can be attached while the pipeline is depressurized. However, to reduce service interruptions to existing customers connected to the main pipeline, hot tapping tools have been developed for metallic pipelines that can drill or cut into the main pipeline while still in service under gas or water pressure. Prior art for hot-tapping a main plastic pipeline involves attaching a pipe saddle fitting to the main pipeline and then attaching an appropriate tubular adapter having a flange, or some type of mechanical joint outlet connector, to the pipe saddle fitting. Finally, a short length of branch pipe is connected to the tubular adapter, and a hole is drilled in the main pipeline for fluid communication with the branch pipe. A tapping tool, which includes a compression seal butted against the open end of the branch pipe, a drill mounted on a shaft extending through the compression seal and the pipe saddle, and means to advance/retract the drill bit from outside the fitting, is then used to drill the hole in the main pipeline. After the hole is drilled, the drill bit is retracted toward the compression seal within the now pressurized length of branch pipe. If a full flow valve is not included in the branch pipe, a squeeze off tool is used to seal the branch pipe near the pipe adaptor, before removal of the tapping tool. After attaching the remainder of the branch pipe to the tapped section, the full flow valve is opened, or the squeezed section of the branch pipe is rerounded. Use of hot tapping tools has become so common, especially in water distribution, that the manufacturers of the tools have developed dimensional standards for hot tap tools offered for sale.
Several problems, however, are inherent in the prior art techniques for using the standard hot-tap tool on plastic pipelines. The use of the hot-tap tool requires extensive evacuation/back filling for buried pipelines, such that restricted access may prevent installation of the hot tap tool in some locations.
Another problem is that commercially available plastic pipe saddle fittings and plastic tubular adapters having flange or mechanical joint outlet connections are of lengthy and bulky construction. Accordingly, when an available plastic tubular adapter is fused to an available plastic pipe saddle fitting, the passageway of the resulting assembly, through which the drill bit of the tapping tool must pass, is too long to allow use of many commonly sized tapping tools.
Other problems arise because commercially available plastic pipe saddle fittings lack sufficient mass, especially in the base section of the saddle, to overcome the weakening effects of a hole cut in the main pipeline. Once the hole in the main pipe has been cut and the coupon removed, the lack of sufficient mass in the base of the saddle fitting also results in inadequate contact surface for fusion to the main pipe. Accordingly, the lack of contact surface and/or reinforcing mass in the plastic saddle, result in failure of the fitting to provide a pressure rating equal to that of the main host pipe.
Accordingly, a need for a single compact plastic fitting exists. The single fitting desirably integrates the pipe saddle fitting and an appropriate outlet adapter in a single piece having suitable dimensions and strength, by which a tap for a service branch connection may be made into a plastic pipeline using hot tap tools of commercially available dimensions.
It is an object of this invention to provide a permanent saddle fitting of the type described above which is formed as a monolithic unit.
Another object is to provide a permanent pipe fitting for attaching a branch pipe that simplifies temporary use of a standard size hot-tap tool.
It is another object of this invention to provide a fully pressure rated branch outlet connection to a plastic pipe main.
Yet another object of this invention is to provide a fitting for a hottap tool where the fitting does not require temporary clamping of a saddle to the main pipeline.
SUMMARY OF THE INVENTION
According to the present invention, the foregoing and other objects and advantages are attained by a compact monolithic tapping saddle pipe fitting made of weldable plastic, and having dimensions that facilitate use of a standard hot-tap tool. The compact plastic fitting also adapts to a branch pipe to be permanently joined at full pressure rating to a main pipeline. When the standard hot-tap tool is used for plastic pipelines it must be temporarily attached close to the pipeline to be tapped, and the compact size of the inventive fitting facilitates use of the standard tool for hot-tapping plastic pipe. The tapping saddle fitting, which is preferably formed of weldable plastic material, includes a reinforced pipe saddle member having a central opening. The saddle is permanently joined to one end of a tubular connection member to form a tee shape plastic pipe fitting having an open passageway extending through the saddle and the tubular member. The fitting is mountable on a main plastic pipeline with the axis of the pipe saddle substantially in alignment with the axis of the main pipeline, and the axis of the tubular member disposed substantially transverse of the axis of the pipe saddle.
According to one aspect of this invention the plastic tapping saddle pipe fitting is fabricated using either a molding operation, or formed in a machined fabrication from suitable "bar stock" to produce a monolithic unit. In another aspect the outlet end of the tubular connection member includes either a flange or a mechanical joint for outlet connections. In yet another aspect the tapping saddle fitting is secured to the main pipeline to be tapped using either heat-fusion, or electro-fusion, or solvent welding.
Other objects and advantages of the invention will be apparent from the appended claims and from the detailed description of the invention when read in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation end view of a plastic hot-tap saddle pipe joint fitting according to this invention, where the saddle is arranged to be placed on a pipeline, and the branch outlet is effected by a flange connection.
FIG. 2 is an elevation view in cross section, illustrating the plastic hot-tap saddle pipe joint fitting co-joined with the pipeline main by fusion.
FIG. 3 is an elevation end view of a prior art combination of two separate fittings for connecting a branch pipe.
FIG. 4A is a perspective view illustrating a prior art plastic branch saddle having insufficient reinforcing mass.
FIG. 4B is a view, similar to FIG. 4A, having enlarged heat-fusion area according to one aspect of the invention.
FIG. 5 is an elevation view in cross section illustrating essential features of a commercially available standard hot-tap tool secured to a pipeline through a hot-tap saddle according to this invention, including a mechanical joint option for connection of a shut-off valve.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a monolithic tapping saddle pipe joint fitting shown generally at 10, preferably formed of a moldable plastic material, includes an axially extending tubular connection member 20 having a flange 26 for affecting an outlet connection, and an axis 30. The monolithic fitting 10 also includes a pipe saddle member 22 having two oppositely disposed shoulder members 24. The pipe saddle member has an axis 15. As shown in FIG. 1, the pipe saddle fitting has a curved surface 16 suitable for positioning the fitting on a main pipeline 18. In the mounted position, the axis 15 of the saddle member 22 extends generally in parallel relation with the axis of the main pipeline 18. The axis 30 of the tubular connection member 20, extends transversally to the axis 15 of pipe saddle member 22 thus extending outwardly from the saddle member 22 and the main pipeline 18. The tubular connection 20 forms a passageway 12, which extends through a central opening in the pipe saddle 22, and through which a medium flowing in the pipeline 18 can enter the tubular connection member 20 through a tapped hole in the pipeline 18.
Also as viewed in FIG. 1, the saddle member 22 has an upper shell shaped section 14 having a circumferentially extending inner surface 16 that extends for an angular extent of about 180°. The circumferential inner surface 16 is arranged to extend around part of the circumference of the main pipeline 18, and also extends in the axial direction of the main pipeline 18. The angular extend of the circumferentially extending inner surface 16 of the shell shaped section 14 is arranged so that the pipe joint fitting 10 can be positioned radially about the axial direction of the pipeline 18. Preferably the saddle member 22 has a snug fit to the pipeline so that a snapping or gripping action is noticed when it is placed on the pipeline 18. Accordingly, in the mounted position the pipe saddle member 22 extends in generally parallel relation with the pipeline axis, and the tubular member 20 is disposed transversally of the pipe saddle member 22, thus extending outwardly from the saddle member 22 and the main pipeline 18. A split flange ring 28 having a bolt hole 27 facilitates connection of the flange 26 to a branch pipe (not illustrated) having a similar end connection.
Referring now to FIG. 2, where like reference numerals are used for the parts of the fitting illustrated in FIG. 1, there is illustrated a tapped hole 29 in the pipeline 18 and the opening in saddle member 22 that cooperate with the tubular member 20 to form a fluid passage zone 12. Fluid passage zone 12, which includes the tubular member 20, opens through the inner surface 17 of the saddle member 22 so that it encircles the tapping connection opening 29 made in the pipeline 18. The diameter of the opening in the main pipeline 18 may be nominally equal to the inside diameter of the main pipe 18, or tapped hole 29 may be reduced in size and be smaller than the inside diameter of the main pipe 18. The passage zone 12 is substantially round in section transverse to the axis 30.
FIG. 3 illustrates a prior art technique using two separate fittings to affect a branch pipe connection. In this prior art scheme an outlet adapter 21 having a flange 19 is fused to a branch saddle 23 and the fused combination of adapter 21 and saddle 23 is attached to the main pipeline 18. Using this arrangement, however, results in a distance from the flange 19 to the main pipe 18 (illustrated as dimension A), that is too long to allow use of a standard size commercially available hot-tapping tools.
FIG. 4A illustrates a prior art branch saddle fitting having insufficient reinforcing mass, and accordingly insufficient heat-fusion contact area 16 to obtain full pressure rating of the fitting when attached to a main pipe. FIG. 4B illustrates one aspect of this invention that provides heat-fusion area 16 and reinforcing mass 22 in the base area necessary to achieve a fitting pressure rating equal to that of the untapped main pipe.
A simple monolithic production of a molded branch saddle fitting 10 can be affected from plastic material in an injection molding procedure. Alternately a production of the fitting 10 can be effected by machining from suitable "bar stock" material. Selection of plastic material for fabrication of the tapping saddle fitting 10 should be compatible with the fluid being transported by the pipe being tapped. Preferably it is formed of synthetic resinous materials such as thermoplastics. Suitable thermoplastic materials include olefin polymers and normally solid, moldable polyamide polymers with a preferred olefin polymer being a high density polyethylene, and a preferred polyamide polymer being nylon.
In use the tapping saddle pipe joint fitting 10 is first securely attached to the main plastic pipe 18 to be tapped by any suitable means such as heat-fusion or electro-fusion. For example, the fitting 10 can be attached by fusing the saddle portion 22 of the plastic fitting 10 to the main pipe 18 with the use of a heating iron or the like. As previously mentioned electro-fusion or solvent welding may also be employed, and thereafter, a standard hot tap tool is attached. Heating irons for attaching the plastic saddle 22 of the fitting to the main plastic pipe have found widespread use. The heating iron typically has a curvature complementary to the curvature of the fitting to facilitate simultaneous heating of the surfaces of the saddle 22 and the main plastic pipe 18 until the plastic at the junction of the two surfaces softens and melts. When sufficient softening or melting has occurred, the heating iron is removed and the saddle 22 of the fitting that contacts pipe 18 is directly fused to the main pipe 18, followed by cooling.
Referring now to FIG. 5, where like reference numerals are used for the parts of the fitting illustrated in FIG. 1, there is illustrated a standard commercially available hot-tap tool 40 and an isolation valve 42 installed on a plastic tapping saddle pipe fitting 22, and positioned to cut into a pressurized main pipe 18 by advancing a cutter 41 through the pipeline 18. As illustrated a mechanical joint is used to connect the plastic fitting 22 and the metal isolation valve 42. The mechanical joint includes a rubber gasket 44 and draw bolts 46. While any suitable connections between the parts illustrated in FIG. 5 is satisfactory, a flange connection between the hot-tap tool 40 and the isolation valve 42 is illustrated. The isolation valve and the hot-tap tool, used in the practice of the invention illustrated in FIG. 5, are each well known components available in various sizes and from various vendors such as Mueller Co., 500 West Eldorado St., Decatur, Ill. 62525.
This invention has been described in reference to a standard hot-tap tool having dimensions for use with metal pipe fittings, and which can be used with a novel tapping saddle of the present invention for tapping plastic pipe. Reasonable modifications and alterations of this invention will become apparent to those skilled in the art from the foregoing discussion and accompanying drawings, and it should be understood that this invention is not to be unduly limited thereto. | A compact hot-tap saddle pipe fitting made of weldable plastic material integrates a branch saddle and a tubular adapter into a monolithic tee shaped unit. The fitting, which is characterized by short overall dimensions and a reinforced base portion, allows a fully pressure rated connection of a branch line to a main plastic pipeline using an isolation valve and a standard size hot-tap cutting tool. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to gloves that bias a hand into an optimal position for swimming. In particular, it relates to gloves that promote muscle memory of the optimal hand position and improve swimming performance.
[0003] 2. Description of the Related Art
[0004] New swimmers and those learning to swim most often exhibit one of two reactions on entering the water. They may show a ‘startle’ reflex leading to splayed fingers or a stress reflex tending to curl the fingers into a fist.
[0005] Either reaction is detrimental to swimming performance as it limits the power of the hand to push water down the body, the key propulsion mechanism in all four functional strokes.
[0006] New swimmers and those learning to swim often struggle with a number of barriers to developing efficient strokes, such as getting the correct body position to remain buoyant, keeping the kick going, getting the arm action rhythmic and effective and breathing. These barriers can take a considerable amount of time to overcome and the ability of new swimmers to focus on overcoming multiple barriers simultaneously is limited.
[0007] Furthermore, all swimmers suffer inefficiency in their stroke without optimisation of their hand position for swimming.
[0008] The present invention seeks to address these and other problems.
[0009] Whilst it is noted that there are a wide range of swimming aids and gloves readily available, the purpose of these is to provide additional thrust during a stroke by widening the effective hand width, either by a hard surface paddle that has an increased surface area or through a mechanism that provides webbing between the fingers.
[0010] They do not take into consideration the need to optimise a swimmer's hand position. Specifically, they do not limit the fingers ability to spread widely, in fact many promote this poor finger position, and they do not constrain the ability of the fingers to touch one another or to ball into a fist.
SUMMARY OF THE INVENTION
[0011] According to the present invention there is provided a glove for biasing a user's hand into an optimal position for swimming, the glove comprising a resilient portion that reduces splaying of fingers during a swimming stroke.
[0012] The glove/paddle may be comprise finger portions that extend to the first knuckle of the outside fingers, i.e. ring and baby fingers, when being worn, and these finger portions may be non-webbed.
[0013] The resilient and/or an elasticated portion may surround the fingers when being worn.
[0014] The glove may be of laminar construction and comprise a resilient member that consists of one or more layers of resilient material and/or an elasticated component.
[0015] The glove may comprise an adjustable attachment means.
[0016] The glove may be made of neoprene, and the resilient portion may be made of moulded plastic.
[0017] Using the glove of the present invention a new swimmer or a learner can achieve an optimal hand position for swimming. Additionally, with prolonged use of the glove of the present invention, the new swimmer or learner will train their muscle memory to automatically adopt the optimal hand position when swimming even when the aid is no longer in use.
[0018] Furthermore, more experienced swimmers will be able to use the glove of the present invention to attain an optimal hand position and improve their swimming efficiency and performance.
[0019] Also, the invention enables the barriers to swimming to be reduced by ensuring that swimmers are able to maintain sufficient forward momentum to remain buoyant and thereby become stronger swimmers.
[0020] Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Embodiments of the present invention will now be described, by way of example only, with reference to the attached drawings, in which:
[0022] FIG. 1 is a perspective view showing a glove of the present invention in an open conformation;
[0023] FIG. 2 is a perspective view showing a glove of the present invention in a closed conformation;
[0024] FIG. 3 is an elevation view of a glove of the present invention in a closed conformation;
[0025] FIG. 4 is an exploded elevation view of a glove of the present invention in a closed conformation;
[0026] FIG. 5 is an exploded perspective right hand view showing a glove of the present invention in a closed conformation;
[0027] FIG. 6 is an exploded perspective left hand view showing a glove of the present invention in a closed conformation;
[0028] FIG. 7 is a plan view showing a glove of the present invention being worn;
[0029] FIG. 8 is an underneath view showing a glove of the present invention being worn; and
[0030] FIG. 9 is a side view showing a glove of the present invention being worn.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art how to make and/or use the invention.
[0032] It is not natural for people to swim efficiently as this activity is not optimised during human evolution (Minetti et al. 2009. Biomechanics 42:2188-2190). Therefore, people need to actively learn to swim and develop efficient techniques to support this ability. This process requires learning to hold and move individual limbs and body parts and the coordination of many individual actions.
[0033] Typical human reactions to stress include a startle reflex that includes splaying of fingers, while reaction to pressure often results in clenching of the fist. Even mild forms of such reactions displayed by new or learning swimmers on entering the water will reduce or limit the efficiency of a swimming stroke.
[0034] Hand position of elite swimmers has been studied, and an optimal hand position for swimming determined. This optimal hand position is found in a resting hand with fingers adopting a naturally spaced position where the gap between fingers are equal to half the width of the fingers. This hand position can increase the power of the hand action by up to 53% compared to widely spaced or closed fingers (Lorente et al. 2012. Journal of Theoretical Science 308:141-146).
[0035] As provided in FIG. 1 , a glove of the present invention promotes the adoption of the optimal hand position in a swimming stroke. The glove of FIG. 1 is formed from a body member 1 having a thumb opening/hole 2 , closure flaps 3 , finger portions 4 , a resilient member 5 and an additional layer member 6 . The resilient member may also be an elasticated component. The finger portions 4 and the resilient member 5 are connected to opposing faces of the body member 1 , and an additional layer member 6 is attached to the resilient member. The glove may by secured to the hand, in use, by securing together of the closure flaps 3 using an engagement means 8 such as a hook and loop type fastener. The engagement means forming an adjustable attachment means. In the closed position the glove is secured to the user's hand during a swimming stroke. The finger portions 4 are dimensioned to only extend from the palm to or below the first knuckle of a user's hand.
[0036] It will be appreciated that alternative arrangements of the finger portions 4 and resilient member 5 can be provided. For example, they may be in direct contact, they may be separated by the body member as shown or they may be separated by one or more layer members. Additionally, the resilient member may extend the full length or only part of the length of the finger portions.
[0037] It will be further appreciated that the body member 1 , the finger portions 4 and/or the additional layer member 6 may be made of any material that does not noticeably increase resistance of the hand in water or increase buoyancy of the hand, for example, neoprene.
[0038] It will also be appreciated that the resilient member 5 will be made of a resilient material that is capable of providing a biasing resistance to restrict or inhibit the movement of individual fingers during a swimming stroke, for example, moulded plastic.
[0039] FIGS. 2-6 show the glove of FIG. 1 in a closed configuration with closure flaps 3 engaged so as to secure the glove to a user's hand.
[0040] It will also be appreciated that any suitable engaging mechanism can be provided to secure the closure flaps 3 such that, in use, the glove is secured to the hand during a swimming stroke.
[0041] FIGS. 7-9 show a glove of the present invention in use with closure flaps secured to secure the glove to the hand, the finger portions 4 encircling the fingers and connected to the resilient member 5 .
[0042] As mentioned above for FIGS. 1-6 , a suitable engaging mechanism can be provided on one or more closure flaps to ensure that the glove remains secured to the hand when in use.
[0043] As mentioned above for FIGS. 1-6 , an additional layer member covers the resilient member. In the arrangement of FIG. 8 , the resilient member 5 is not covered by a layer member.
[0044] As will be appreciated from the above description, the present invention provides a glove that enables biasing a swimmer's hand to an optimal position during a swimming stroke. It also enables a new swimmer or a learner swimmer to develop the required muscle memory to promote an optimal hand position during a swimming stroke.
[0045] It will also be appreciated that a moulded paddle with equivalent functionality may also be designed.
[0046] The present invention promotes optimal hand position for swimming which is defined as slightly curved palm and fingers, with fingers lengthened and naturally spaced, where the inter-digit distance is approximately half of the digit width. This position is equivalent to standing with hands at rest by the side of the body.
[0047] Hands held in an optimised position when in the water have a significantly increased power. Optimal hand position is hard to maintain, even for those who are aware of it because it requires focus on fine motor control of the fingers when many gross motor movements are occurring simultaneously, such as kicking legs and moving arms, that distract the brain from hand position. The present invention allows a user to develop this.
[0048] The human body is capable of developing a sense of muscle memory for much repeated movements to the point that the movement is completed in an identical fashion often without the person even being consciously aware, such as changing gear while driving. Developing muscle memory for unhelpful habits, such as widely spaced fingers while swimming, is particularly hard to correct. A focus on developing positive habits early on in skill development enables those habits to become embedded in that persons on-going behaviour, to become a sub-conscious skill
[0049] In this way, the invention is an aid that enables optimal hand position while swimming, without the user having to consciously remember to hold their fingers correctly. Furthermore it will increase the user's hand power, increasing the rate at which they can overcome barriers to learning to swim or improving their swimming, while also enabling the muscle memory of optimal hand position to be a skill they carry with them for life. | A glove for biasing a user's hand into an optimal position for swimming. The glove having a body member with a thumb hole and closure flaps, four finger portions secured to the body member and a resilient member secured to the body member and extending across the four finger portions, wherein the resilient member in cooperation with the four finger portions reduces splaying of fingers during a swimming stroke, restricts balling of the hand when worn and restricts touching of the fingers when worn. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from a co-pending application entitled LOW POWER WIRELESS NETWORKS OF FIELD DEVICES, Ser. No. 60/758,167, filed on Jan. 11, 2006, which is incorporated by reference.
Reference is also made to co-pending applications filed on even date with this application: CONTROL OF FIELD DEVICE ON LOW POWER WIRELESS NETWORKS, Ser. No. 11/652,393; CONTROL SYSTEM WITH WIRELESS ADDRESS DOMAIN TO FIELD DEVICE ADDRESS DOMAIN TRANSLATION, Ser. No. 11/652400; CONTROL SYSTEM WITH PREDICTIVE FIELD DEVICE RESPONSE TIME OVER A WIRELESS NETWORK, Ser. No. 11/652,392; VISUAL MAPPING OF FIELD DEVICE MESSAGE ROUTES IN A WIRELESS MESH NETWORK, Ser. No. 11/652,398; SELECTIVE ACTIVATION OF FIELD DEVICES IN LOW POWER WIRELESS MESH NETWORKS, Ser. No. 11/652,395; and CONTROL SYSTEM WITH WIRELESS MESSAGES CONTAINING MESSAGE SEQUENCE INFORMATION, Ser. No. 11/652,401, which are incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to wireless networks. In particular, the invention relates to a wireless mesh network in which process control messages are communicated between a host and field devices at nodes of the wireless mesh network.
In many industrial settings, control systems are used to monitor and control inventories, processes, and the like. Often, such control systems have a centralized control room with a host computer that communicates with field devices that are separated or geographically removed from the control room.
Generally, each field device includes a transducer, which may generate an output signal based on a physical input or generate a physical output based on an input signal. Types of transducers used in field devices include various analytical equipment, pressure sensors, thermistors, thermocouples, strain gauges, flow sensors, positioners, actuators, solenoids, indicators, and the like. Traditionally, analog field devices have been connected to the process subsystem and the control room by two-wire twisted-pair current loops, with each device connected to the control room by a single two-wire twisted pair loop. Typically, a voltage differential is maintained between the two wires of approximately 20 to 25 volts, and a current between 4 and 20 milliamps (mA) runs through the loop. An analog field device transmits a signal to the control room by modulating the current running through the current loop to a current proportional to the sensed process variable. An analog field device that performs an action under the control of the control room is controlled by the magnitude of the current through the loop, which is modulated by the ports of the process subsystem under the control of the controller.
While historically field devices were capable of performing only one function, more recently hybrid systems that superimpose digital data on the current loop have been used in distributed control systems. The Highway Addressable Remote Transducer (HART) superimposes a digital carrier signal on the current loop signal. The digital carrier signal can be used to send secondary and diagnostic information. Examples of information provided over the carrier signal include secondary process variables, diagnostic information (such as sensor diagnostics, device diagnostics, wiring diagnostics, process diagnostics, and the like), operating temperatures, sensor temperature, calibration data, device ID numbers, configuration information, and so on. Accordingly, a single field device may have a variety of input and output variables and may implement a variety of functions.
Another approach uses a digital communication bus to connect multiple field devices to the host in the control room. Examples of digital communication protocols used with field devices connected to a digital bus include Foundation Fieldbus, Profibus, Modbus, and DeviceNet. Two way digital communication of messages between a host computer and multiple field devices can be provided over the same two-wire path that supplies power to the field devices.
Typically, remote applications have been added to a control system by running very long homerun cables from the control room to the remote application. If the remote application is, for example, a half of a mile away, the costs involved in running such a long cable can be high. If multiple homerun cables have to be run to the remote application, the costs become even higher. Wireless communication offers a desirable alternative, and wireless mesh networks have been proposed for use in industrial process control systems. However, to minimize costs, it is also desirable to maintain existing control systems and communication protocols, to reduce the costs associated with changing existing systems to accommodate the wireless communication.
In wireless mesh network systems designed for low power sensor/actuator-based applications, many devices in the network must be powered by long-life batteries or by low power energy-scavenging power sources. Power outlets, such as 120VAC utilities, are typically not located nearby or may not be allowed into the hazardous areas where the instrumentation (sensors) and actuators must be located without incurring great installation expense. The need for low installation cost drives the need for battery-powered devices communicating as part of a wireless mesh network. Effective utilization of a limited power source, such as a primary cell battery which cannot be recharged, is vital for a well functioning wireless device. Batteries are expected to last more than 5 years and preferably as long as the life of the product.
In a true wireless mesh network, each node must be capable of routing messages for itself as well as other nodes in the mesh network. The concept of messages hopping from node to node through the network is beneficial because lower power RF radios can be used, and yet the mesh network can span a significant physical area delivering messages from one end to the other. High power radios are not needed in a mesh network, in contrast a point-to-point system which employs remote nodes talking directly to a centralized base-station.
A mesh network protocol allows for the formation of alternate paths for messaging between nodes and between nodes and a data collector, or a bridge or gateway to some higher level higher-speed data bus. Having alternate, redundant paths for wireless messages enhances data reliability by ensuring there is at least one alternate path for messages to flow even if another path gets blocked or degrades due to environmental influences or due to interference.
Some mesh network protocols are deterministically routed such that every node has an assigned parent and at least one alternate parent. In the hierarchy of the mesh network, much as in a human family, parents have children, children have grandchildren, and so on. Each node relays the messages for their descendants through the network to some final destination such as a gateway. The parenting nodes may be battery-powered or limited-energy powered devices. The more descendants a node has, the more traffic it must route, which in turn directly increases its own power consumption and diminishes its battery life.
In order to save power, some protocols limit the amount of traffic any node can handle during any period of time by only turning on the radios of the nodes for limited amounts of time to listen for messages. Thus, to reduce average power, the protocol may allow duty-cycling of the radios between On and Off states. Some protocols use a global duty cycle to save power such that the entire network is On and Off at the same time. Other protocols (e.g. TDMA-based) use a local duty cycle where only the communicating pair of nodes that are linked together are scheduled to turn On and Off in a synchronized fashion at predetermined times. Typically, the link is pre-determined by assigning the pair of nodes a specific time slot for communications, an RF frequency channel to be used by the radios, who is to be receiving (Rx), and who is to be transmitting (Tx) at that moment in time.
Some protocols employ the concept of assigning links to nodes on a regular repetitive schedule and thereby enable regular delivery of updates and messages from devices in the network. Some advanced TMDA-based protocols may employ the concept of multiple active schedules, these multiple schedules running all at the same time or with certain schedules activated/deactivated by a global network controller as the need arises. For example, slow active schedules link nodes sending messages with longer periods of time (long cycle time) between messages to achieve low power consumption. Fast active schedules link nodes sending messages more rapidly for better throughput and lower latency, but result in higher power consumption in the nodes. With protocols that allow multiple active schedules, some schedules could be optimized for upstream traffic, others for downstream traffic and yet others for network management functions such as device joining and configuration. Globally activating/deactivating various schedules throughout the entire network in order to meet different needs at different times provides a modicum of flexibility for achieving advantageous trade-offs between power consumption and low latency, but applies the same schedule to all nodes and thus does not provide local optimization.
In a synchronized system, nodes will have to wait to transmit until their next predetermined On time before they can pass messages. Waiting increases latency, which can be very detrimental in many applications if not bounded and managed properly. If the pair of nodes that are linked together are not synchronized properly, they will not succeed in passing messages because the radios will be On at the wrong time or in the wrong mode (Rx or Tx) at the wrong time. If the only active schedule has a long cycle time, the time between scheduled links will be long and latency will suffer. If a fast schedule is activated, the time between scheduled links will be short but battery life will be measurably reduced over time.
Some protocols allow running a slow schedule in the background and globally activating/deactivating an additional fast schedule. Since it takes time to globally activate a fast schedule throughout the entire network and get confirmation back from all nodes that they have heard the global command, the network or sub-network remains in the less responsive mode during the transition time. Furthermore, with a globally activated fast schedule, power is wasted in all the parenting nodes in the network, even those whose descendants will not benefit from the fast schedule. These unappreciative parent nodes must listen more often on the global fast active schedule (i.e. turn their radios On to Rx more often); even though their descendants have nothing extra to send that a regular active schedule would not suffice in that portion of the network.
Some protocols may limit the number of descendants a node can have, thereby reducing the load the node must support. Other protocols may employ a combination of all of these measures to reduce average power consumption. All of these power-saving measures have the effect of reducing the availability of the nodes in the network to do the work of passing messages, thereby increasing the latency of messages delivered through the network. Duty-cycling the radio increases latency. Hopping messages from node to node increases latency. Increasing hop depth (hop count) by limiting the number of descendants increases latency. Running a slow active schedule (long cycle period) increases latency. Even globally activating a fast active schedule takes time. It is likely that the value of information diminishes with time, so the longer the latency, the less valuable the information may be.
BRIEF SUMMARY OF THE INVENTION
A host computer of a control system interacts with field devices through a wireless mesh network. Based upon messages from the host computer that are addressed to selected field devices, the network determines which nodes are required to be active so that messages can be routed to those selected field devices. When the network goes to an active state, the nodes required for communication with the selected field devices remain on while the remaining nodes are allowed to return to the inactive state. After communication between the host computer and selected field devices has ceased, the entire network is returned to an inactive state. Determination of the nodes that must be selectively maintained active can be based upon the addresses of the selected field devices and the communication topology of the wireless mesh network, or can be determined dynamically by those nodes that are actively participating in transmitting and receiving messages.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a control system in which a wireless mesh network routes wireless messages between a host and field devices.
FIG. 2 is a block diagram of a portion of the control system of FIG. 1 , including a host computer, a gateway node, and a wireless node with a field device.
FIG. 3 is a diagram illustrating the format of wireless messages transmitted by the wireless network.
FIG. 4 shows the format of a control message from a host to a field device based upon a control system protocol.
FIG. 5 shows one embodiment of the control message as modified to form the payload of the wireless message shown in FIG. 3 .
FIG. 6 shows another embodiment of the control message as modified with a trailer to form the payload of the wireless message shown in FIG. 3 .
DETAILED DESCRIPTION
FIG. 1 shows control system 10 , which includes host computer 12 , high-speed network 14 , and wireless mesh network 16 , which includes gateway 18 and wireless nodes 20 , 22 , 24 , 26 , 28 , and 30 . Gateway 18 interfaces mesh network 16 with host computer 12 over high-speed network 14 . Messages may be transmitted from host computer 12 to gateway 18 over network 14 , and are then transmitted to a selected node of mesh network 16 over one of several different paths. Similarly, messages from individual nodes of mesh network 16 are routed through mesh network 16 from node-to-node over one of several paths until they arrive at gateway 18 and are then transmitted to host 12 over high-speed network 14 .
Control system 10 can make use of field devices that have been designed for and used in wired distributed control systems, as well as field devices that are specially designed as wireless transmitters for use in wireless mesh networks. Nodes 20 , 22 , 24 , 26 , 28 , and 30 show examples of wireless nodes that include conventional field devices.
Wireless node 20 includes radio 32 , wireless device router (WDR) 34 , and field devices FD 1 and FD 2 . Node 20 is an example of a node having one unique wireless address and two unique field device addresses Nodes 22 , 24 , 26 , and 28 are each examples showing nodes having one unique wireless address and one unique field device address. Node 22 includes radio 36 , WDR 38 , and field device FD 3 . Similarly, field device 24 includes radio 40 , WDR 42 , and field device FD 4 ; node 26 includes radio 44 , WDR 46 , and field device FD 5 ; and node 28 includes radio 48 , WDR 50 , and field device FD 6 .
Node 30 has one unique wireless address and three unique field device addresses. It includes radio 52 , WDR 54 , and field devices FD 7 , FD 8 , and FD 9 .
Wireless network 16 is preferably a low power network in which many of the nodes are powered by long life batteries or low power energy scavenging power sources. Communication over wireless network 16 may be provided according to a mesh network configuration, in which messages are transmitted from node-to-node through network 16 . This allows the use of lower power RF radios, while allowing network 16 to span a significant physical area to deliver messages from one end of the network to the other.
In a low power wireless network that includes field devices, power can be conserved by placing the entire network and the field devices into a low power (Off or asleep) state. The network switches to a high power (On or active) state so that the host computer can interact with field devices. For example, a global duty cycle for the wireless network can be established that defines when all nodes are turned On to receive and transmit messages.
When the wireless network is activated, however, it is wasteful to activate all field devices if only a subset of the field devices is going to be utilized during that On or active period of the wireless network. Power used to activate field devices that will not be involved in communication wastes energy available at the nodes, which can affect the battery life.
In addition, if only a limited number of field devices will be involved in communication, at least some of the nodes of the wireless network will not be needed, since they are not in likely communication paths through the wireless network between the field devices and the host computer. Maintaining the radio On to receive messages, when none will be received, wastes energy and affects battery life.
Control system 10 can micro-manage turning On and turning Off of field devices and turning On and turning Off of wireless nodes, so that only those nodes and field devices necessary for communication taking place need to remain at full power. At the same time, control system 10 can ensure that those field devices and nodes that are required to be at full power remain in the On state while the desired communication with host computer 12 takes place.
In control system 10 , there are circumstances when host computer 12 may need to communicate for an extended period of time with a particular field device. For example, at start up of control system 10 , host computer 12 may do discovery, to detect the presence of each field device and to obtain all stored parameters and configuration data from each field device. During this process, multiple messages will be sent between host computer 12 and each individual field device FD 1 -FD 9 . Another example is when host computer 12 needs to configure one of the field devices FD 1 -FD 9 . The amount of configuration data that needs to transferred results in multiple messages between host computer 12 and the particular field device being configured.
In either of these cases, it would be inefficient to turn On all of the field devices FD 1 -FD 9 when wireless network 16 turns On, when only one field device may be involved in the communication. Control system 10 addresses this issue by maintaining all of the field devices in an asleep or Off state until a control message is received from host computer 12 addressed to the particular field device. At that time, power is provided by the wireless device router (WDR) at that node to the addressed field device. For example, in response to receiving the control message from host computer 12 addressed to field device FD 3 , WDR 38 of node 22 turns On power to field device FD 3 .
In the case of wireless nodes having more than one field device, turning On one of the field devices may require that all of the field devices at that node be turned On. For example, if field devices FD 1 and FD 2 at node 20 share a common power and communication bus with WDR 34 , both field devices FD 1 and FD 2 will turn On when power is applied to the bus.
Once a field device has been powered On, it is desirable to keep that device in a full power state until host computer 12 is done communicating with that field device. Even if wireless network 16 is cycling On and Off according to a scheduled duty cycle, it is desirable to maintain the field device that is communicating with host computer 12 in a full powered state as long as active communication is continuing. Depending upon the type of field device, it may take only a few seconds to as many as 60 seconds for the field device to reach a full powered state in response to a control message from host computer 12 .
When a control message is received from host computer 12 requiring that the addressed field device be turned On, the control message can include a command to maintain the field device in a full powered On state for a particular period of time specified by host computer 12 as being necessary to complete the intended communication. Alternatively, the command that the field device be maintained in the On state until interaction with host computer 12 has halted. This can be determined by the wireless device router associated with the field device, which receives the control messages from host computer 12 and routes them to the field device, and also receives responses from the field device that are sent back to host computer 12 . When a period of message inactivity has occurred, the wireless device router automatically turns Off the field device.
By individually controlling the power state of individual field devices FD 1 -FD 9 , control system 10 reduces overall power consumption of wireless network 16 , and in particular power consumption at individual nodes 20 - 30 of network 16 . By returning the field device to a low power state only after communication with host computer 12 has halted, responsiveness between control computer 12 and the particular field device is enhanced. Undesirable transitions of the field device between full power (On) and low power (Off) states are avoided.
Another way in which power can be conserved at nodes 20 - 30 of wireless network 16 is by allowing those nodes that will not be participating in communication to go into a low power (Off) state while those nodes that are actively participating in communication remain in an extended high power (On) state so that host computer 12 can complete its communication with a selected field device.
In a wireless mesh network, messages typically travel from node to node. Alternate, redundant paths for wireless messages will typically exist. When a message is directed to a particular field device within wireless mesh network 16 , several nodes may be involved in receiving and transmitting the message on to the ultimate destination. For example, consider a message intended for field device FD 7 at node 30 . The path of the wireless message to node 30 may pass from gateway 18 through nodes 20 and 22 to node 30 . Alternatively, the message may pass through node 26 to node 30 , or through nodes 24 and 28 to node 30 . A similar return path may exist for the response message from field device FD 7 that is sent from node 30 to gateway 18 and then to host computer 12 . If the communication between host computer 12 and field device FD 7 takes place on a path from gateway 18 through node 26 to node 30 , and back along that same path, then the other nodes 20 , 22 , 24 , and 28 are not needed as long as the communication will only involve host computer 12 and field device FD 7 .
Gateway 18 receives the messages that host computer 12 wants sent over wireless network 16 . When a high power (On) state of wireless network 16 occurs, gateway 18 can send a message to each node that will be involved in receiving and transmitting the messages from host computer 12 and instruct those nodes to remain On for a specified period of time, or until the communication ends. Gateway 18 can identify the nodes that will be involved by maintaining information on signal routing paths within network 16 . Gateway 18 can periodically interrogate each node to determine the links that node has established with neighboring nodes to transmit and receive messages. Based upon that information, the likely path or paths of the messages from host computer 12 can be identified by gateway 18 , and used to provide instructions to the required nodes. Those nodes that do not receive a message from gateway 18 instructing them to stay On will automatically turn Off at the end of the normal high power (On) state in the communication duty cycle. The remaining devices, which have been instructed to remain On, will remain in a high power (On) state as long as host computer 12 is continuing to communicate with at least one field device.
Alternatively, gateway 18 can provide messages to each of the nodes that will not be actively involved in planned communications instructing those nodes to turn Off. Any node that does not receive an instruction to turn Off will remain On. This approach, however, can result in a node remaining On, even though it is not involved in communication, simply because it did not receive the message to turn Off.
Another way to way to manage which nodes remain On and which turn Off requires that any device that has received and transmitted a message during the normal high power (On) portion of the communication duty cycle to remain On until it either receives a message from gateway 18 instructing it to turn Off, or until a period of time has elapsed without any further message being received or transmitted by that node. In this way, network 16 dynamically configures itself to maintain On the nodes that are necessary to maintain so that messages can be routed to and from target field devices. Those nodes that are not involved will automatically turn Off at the end of the high power (On) portion of the duty cycle.
Allowing the communication to continue with an extended On state involving only those nodes actively involved in communication means latency can be reduced and communication improved, without permanently causing wireless network 16 to remain in a On state. When communication ceases, the nodes that have been involved in the extended On state will be resynchronized with the normal Off/On communication duty cycle of wireless network 16 .
In a wired control system, interaction between the host computer and the field devices occurs using well known control messages according to a control message protocol such as HART, Fieldbus, Profibus, or the like. Field devices capable of use in wired control systems (such as field devices FD 1 -FD 9 shown in FIG. 1 ) make use of control messages according to one of the known control message protocols. Wireless nodes 20 - 30 , which are part of wireless network 16 , cannot directly exchange these well known control messages with host computer 12 because the wireless communication over network 16 occurs according to a wireless protocol that is general purpose in nature.
Rather than require host computer 12 and field devices FD 1 -FD 9 to communicate using wireless protocol, a method can be provided to allow sending and receiving well known field device control messages between host computer 12 and field devices FD 1 -FD 9 over wireless network 16 . The well known field device control messages are embedded into the general purpose wireless protocol so that the control messages can be exchanged between host computer 12 and field devices FD 1 -FD 9 to achieve control of an interaction with field devices FD 1 -FD 9 . As a result, wireless network 16 and its wireless communication protocol is essentially transparent to host computer 12 and field devices FD 1 -FD 9 . In the following description, the HART protocol will be used as an example of a known control message protocol, although the invention is applicable to other control message protocols (e.g. Foundation Fieldbus, Profibus, etc.) as well.
A similar issue relates to the addresses used by host computer 12 to direct messages to field devices FD 1 -FD 9 . In wired systems, the host computer addresses each field device with a unique field device address. The address is defined as part of the particular communication protocol being used, and typically forms a part of control messages sent by the host computer to the field devices.
When a wireless network, such as network 16 shown in FIG. 1 is used to route messages from the host computer to field devices, the field device addresses used by the host computer are not compatible with the wireless addresses used by the communication protocol of the wireless network. In addition, there can be multiple field devices associated with a single wireless node, as illustrated by wireless nodes 20 and 30 in FIG. 1 . Wireless node 20 includes two field devices, FD 1 and FD 2 , while wireless node 30 is associated with three field devices, FD 7 -FD 9 .
One way to deal with addresses is to require host computer 12 to use wireless addresses rather than field device addresses. This approach, however, requires host computer 12 to be programmed differently depending upon whether it is communicating over wired communication links with field devices, or whether it is communicating at least in part over a wireless network. In addition, there remains the issue of multiple field devices, which will typically have different purposes, and which need to be addressed individually.
An alternative approach uses gateway 18 to translate field device addresses provided by host computer 16 into corresponding wireless addresses. A wireless message is sent to the wireless address, and also includes a field device address so that the node receiving the message can direct the message to the appropriate field device. By translating field device addressees to corresponding wireless addresses, host computer 12 can function in its native field address domain when interacting with field devices. The presence of wireless network 16 is transparent to host computer 12 and field devices FD 1 -FD 9 .
Still another issue caused by the use of wireless network 16 to communicate between host computer 12 and field devices FD 1 -FD 9 is the unavailability of field devices because of power conservation. In a wired control system, the host computer interacts with field devices as if they were available on demand. The assumption is that the field devices are always powered up and available.
In a low power wireless network, this is not the case. To conserve power, field devices in a low power wireless network are unavailable, or asleep, most of the time. Periodically, the wireless network goes into an active state during which messages can be communicated to and from the field devices. After a period of time, the wireless network again goes into a low power sleep state.
If the host computer attempts to communicate during a period when the wireless network is in a sleep state, or when a particular field device is in a low power sleep state, the failure of the field device to respond immediately can be interpreted by the host computer as a communication failure. The host computer does not determine the particular route that messages take through the wireless network, and does not control the power up and power down cycles for wireless communication. As a result, the host computer can interpret a lack of response of field devices as a device failure, when the lack of response is an inherent result of the way that communication takes place within a low power wireless network.
In order to make the presence of wireless network 16 transparent to host computer 12 , gateway 18 decouples transmission of field device messages between host computer 12 and wireless network 16 . Gateway 18 determines the current state of wireless network 16 and tracks its power cycles. In addition, it maintains information on the response times required for a field device to be turned on and then be ready to provide a response message to a control message from host computer 12 .
When a message is provided by host computer 12 to gateway 18 , a determination of an expected response time is made based upon the field device address. That expected response time is provided to host computer 12 , so that host computer 12 will not treat the absence of a response message prior to the expected response time elapsing as a communication failure. As a result, host computer 12 is allowed to treat field devices FD 1 -FD 9 as if they were available on demand, when in fact wireless network 16 and field devices FD 1 -FD 9 are not available on demand.
FIG. 2 shows a block diagram of a portion of the control system 10 shown in FIG. 1 . FIG. 2 , host computer 12 , high-speed network 14 , gateway 18 , and wireless node 22 are shown.
In FIG. 2 , host computer 12 is a distributed control system host running application programs to facilitate sending messages to field devices FD 1 -FD 9 , and receiving and analyzing data contained in messages from field devices FD 1 -FD 9 . Host computer 12 may use, for example, AMS™ Device Manager as an application program to allow users to monitor and interact with field devices FD 1 -FD 9 .
Host computer 12 communicates with gateway 18 using messages in extendable markup language (XML) format. Control messages intended for field devices FD 1 -FD 9 are presented according to the HART protocol, and are communicated to gateway 18 in XML format.
In the embodiment shown in FIG. 2 , gateway 18 includes gateway interface 60 , mesh manager 62 , and radio 64 . Gateway interface 60 receives the XML document from host computer 12 , extracts the HART control message, and modifies the control message into a format to be embedded in a wireless message that will be transmitted over wireless network 16 .
Mesh manager 62 forms the wireless message with the HART control message embedded, and with the wireless address of the node corresponding to the field device to which the HART message is directed. Mesh manager 62 may be maintaining, for example, a lookup table that correlates each field device address with the wireless address of the node at which the field device corresponding to that field device address is located. In this example, the field device of interest is device FD 3 located at wireless node 22 . The wireless message according to the wireless protocol includes the wireless node address, which is used to route the wireless message through network 16 . The field device address is contained in the HART message embedded within the wireless message, and is not used for routing the wireless message through network 16 . Instead, the field device address is used once the wireless message has reached the intended node.
Mesh manager 62 causes radio 64 to transmit the wireless message, so that it will be transmitted by one or multiple hops within network 16 to node 22 . For example, the message to node 22 may be transmitted from gateway 18 to node 20 and then to node 22 , or alternatively from gateway 18 to node 26 and then to node 22 . Other routes are also possible in network 16 .
Gateway interface 60 and mesh manager 62 also interact with host computer 12 to manage the delivery of control messages to field devices as if wireless network 16 were powered on even though it may be powered Off (i.e. sleep mode). Mesh manager 60 determines the correct powered state of wireless network 16 . It also calculates the time of the power cycles in order to determine the future time when wireless network 16 will change state from power On to Off, or from power Off to On. Response time can be affected if a message is sent while power is on to the wireless network, but a response will not occur until the next power on cycle. Still another factor is the start-up time of the field device. Mesh manager 62 or gateway interface 60 may maintain a data base with start-up times for the various field devices. By knowing field device address, an expected start-up time can be determined.
Based upon the current power state of wireless network 16 , the amount of time before wireless network will change state, the field device's start-up time, expected network message routing time, and the potential for a response to occur in the next power on cycle rather than the current cycle, estimated times required for the message to be delivered to the field device and for the response message to return to gateway 18 can be calculated. That information can then be provided to host computer 12 . Since host computer 12 will not expect a response prior to the estimated response time, the failure to receive a message prior to that time will not be treated by host computer 12 as a communication failure or field device failure.
Based upon the factors affecting response time, gateway 18 may also determine the best strategy to attempt communication with the field device given the known power cycle of wireless network 16 . For example, if a power cycle is about to change from On to Off, a better strategy may be to wait until the beginning of the next power on cycle to begin routing the message through wireless network 16 .
As shown in FIG. 2 , wireless node 22 includes radio 36 , wireless device router (WDR) 38 , and field device FD 3 . In this particular example, field device FD 3 is a standard HART field device, which communicates field data using the HART control message protocol. Field device FD 3 is powered On and Off by, and communicates directly with, WDR 38 .
The wireless message transmitted over network 16 is received at radio 36 of wireless node 22 . The wireless message is checked by WDR 38 to see whether it is addressed to node 22 . Since node 22 is the destination address, the wireless message is opened, and the embedded HART message is extracted. WDR 38 determines that the HART message is intended for field device FD 3 based upon the field device address contained in the embedded HART message.
For power saving reasons, WDR 38 may be maintaining field device FD 3 in sleep mode until some action is required. Upon receiving the HART message contained within the wireless message, WDR 38 takes steps to start up field device FD 3 . This may be a matter of only a few seconds, or may be, for example, a delay on the order of 30 to 60 seconds. When field device FD 3 is ready to receive the HART message and act upon it, WDR 38 transmits the HART control message to field device FD 3 .
The message received by field device FD 3 may require providing a message in response that includes measurement data or other status information. Field device FD 3 takes the necessary action to gather the measurement data or generate the status information, generates a response message in the HART control format, and transmits the message to WDR 38 . The HART response message is then modified and embedded into a wireless response message according to the wireless protocol, and addressed to gateway 18 . WDR 38 provides the wireless response message to radio 36 for transmission onto wireless network 16 . The wireless response message is then transmitted in one or multiple hops to gateway 18 , where the HART response message is extracted from the wireless response message, is formatted in XML, and is transmitted over high-speed network 14 to host computer 12 .
FIG. 3 shows a diagram of a typical wireless message sent over the wireless network shown in FIGS. 1 and 2 . Wireless message 70 includes wireless protocol bits 72 , payload 74 , and wireless protocol bits 76 . Protocol bits 72 and 76 are required for proper routing of wireless message 70 through mesh network 16 to the desired destination. Payload 74 represents the substance of the control message being transmitted. In the present invention, the control message (in the control message protocol used by both host computer 12 and field devices FD 1 -FD 9 ) is embedded within wireless message 70 as payload 74 .
FIG. 4 shows the format of control message 80 as generated by host computer 12 . In this particular example, control message 80 is configured using the HART protocol. Control message 80 includes preamble 82 , delimiter 84 , field device address 86 , command 88 , byte count 90 , data 92 , and check byte 94 . Control message 80 is modified at gateway interface 60 and then embedded into wireless message 70 as payload 74 .
FIG. 5 shows the format of payload 74 formed from control message 80 . To produce payload 74 , interface 60 removes physical layer overhead from control message 80 and adds sequence information.
As shown by a comparison of FIGS. 4 and 5 , the first difference between payload 74 and control message 80 is that preamble 82 has been removed. Since the control message will be sent over the network using the wireless protocol, the use of a preamble is unnecessary. Removal of preamble 82 improves efficiency of network 16 by eliminating unnecessary information.
The second difference between payload 74 and control message 80 is the addition of message ID 96 , which is a two-byte number that follows data 92 , and precedes check byte 94 . The removal of preamble 82 and the addition of message ID 96 also requires that check byte 94 be recalculated.
The purpose of message ID 96 is for stale message rejection. This allows the receiver of a message to reject out of order messages. Wireless mesh network 16 is designed such that messages can take multiple paths to get to their destination. The message is passed from one node to another, and it is possible that the message may be delayed at a particular node. This could be caused by interference or poor signal quality. If a message is delayed long enough, host 12 may issue a retry and/or a new message. In that case, it is possible that one or more messages may arrive at the destination node before the delayed message is delivered. When the delayed control message is delivered, message ID 96 can be used to accept or reject the control message.
FIG. 6 shows a second embodiment of the format of payload 74 , in which trailer function code 98 and trailer payload (or message ID) 96 form trailer frame 100 , which is appended to the control message formed by delimiter 84 , field device address 86 , command 88 , byte count 90 , data 92 and check byte 94 . Trailer 100 is not included in check byte 94 , and instead depends on the wireless network protocol layers for data integrity and reliability.
Trailer 100 contains function code 98 and payload 96 (which includes the message ID, if any). Function code 98 is an unsigned byte which defines the content of trailer 100 . Undefined payload bytes such as additional padding bytes will be ignored. Use of trailer 100 only applies to messages between gateway 18 and wireless field devices FD 1 -FD 9 . Table 1 shows an example of function codes defined for trailer 100 :
TABLE 1
Function
Payload Length and
Code
Meaning
Description
0
No Message ID
0-2 bytes (optional padding)
1
Force Accept
2 bytes - message ID
2
Clear Force Accept
2 bytes - message ID
With Force
3
Normal Message ID
2 bytes - message ID
Function codes 0-3 are used with reference to a message ID. Message IDs are used for stale message rejection on wireless mesh network 16 . This allows the receiver of a message to reject out of order messages. Additionally, message IDs can be used by gateway 18 to determine whether published data has arrived out of order.
Rules for generating the Message ID are as follows:
The message ID enumerates a message sequence from a sender to a receiver. It is a two byte unsigned value which must be unique and increasing by one with each new message ID.
A new message ID should be generated for every request/response transaction. Retries of a request from a sender to a receiver may re-use a message ID provided that there is no more than one request outstanding from a sender to a receiver. After receiving a valid request message with a valid message ID, the field device must echo back the received message ID with the response.
A new message ID should be generated for every publish message from a device. Publish message IDs are generated independently of request/response message IDs.
Rules for validating the Message ID are as follows:
The receiver must implement a window for validating message IDs so that the validity comparison survives a rollover of the message ID counter. As an example, any messages within a window of 256 previous IDs could be ignored as out of order by the WDR/field device. But, if message ID is safely outside the window the receiver should accept the message. Any accepted message will cause the message ID to be cached as the last valid received message ID.
After a restart, a receiver may accept the first message ID it receives or else it must initialize its validity-checking in whatever manner the device application sees fit. A guideline for this initialization would be for a device to always accept new stateless requests without requiring a device publish to first reach the gateway.
The receiver of a published message with an invalid (out of order) ID may either use or reject the message, depending on the receiver's application.
Rules for interpreting function codes are as follows:
A sender can send a message without a message ID by either omitting trailer 100 or by specifying NO MESSAGE ID as the function code. If a response is generated and the WDR/field device supports trailers, the return function code should be set to “NO MESSAGE ID”.
If a message ID is provided, it must be accepted if the function code is set to FORCE ACCEPT or CLEAR FORCE ACCEPT WITH FORCE. A message with a function code of NORMAL ID will be subject to potential discard via the message ID validation rules.
If gateway 18 has reset, it should make its first request using the FORCE ACCEPT function code. The will force the receiving field device to accept the request and the attached message ID. This relieves gateway 18 of needing to learn the value of the device's valid message ID counter. Gateway 18 should stop using FORCE ACCEPT once it has received a valid response message with the matching message ID.
Gateway 18 should honor the CLEAR FORCE ACCEPT WITH FORCE function code as a valid message ID, but a WDR/field device should not send CLEAR FORCE ACCEPT WITH FORCE to gateway 18 .
If a WDR/field device in the system has reset, it should send publish messages with the command set to FORCE ACCEPT. This will force gateway 18 to accept the published data.
If gateway 18 sees the FORCE ACCEPT function code, it may issue a CLEAR FORCE ACCEPT WITH FORCE in a subsequent message along with a valid message ID.
On receipt of CLEAR FORCE ACCEPT WITH FORCE, the WDR/field device should clear the force accept condition and always accept the message ID provided.
The use of embedded control messages (in a control message protocol) within wireless messages (in a wireless protocol) enables the host computer of a distributed control system to interact with field devices through a wireless communication network. Control messages can be exchanged between the host computer and the field devices using known control message formats, such as HART, Fieldbus, or the like, without having to be modified by either the host computer or the field devices to accommodate transmission of the control messages over the wireless network. The control message is embedded within the wireless communication protocol such that the substance of the control message exchanged between the host computer and the field device is unmodified as a result of having passed through the wireless network.
Control messages that are too large to be routed through the wireless communication protocol can be broken into parts and sent as multiple parts. Each part is embedded in a wireless message, and the multiple parts can be reassembled into the original control message as the multiple parts exit the wireless network. By use of a message ID in the embedded control message, the multiple parts can be reassembled in proper order, even though individual wireless messages having embedded parts of the original control message may take different paths through the wireless network.
The translation of field device addresses to corresponding wireless addresses allows host 12 to function in its native field device address domain, while interacting with field devices within the wireless address domain. The use of wireless network 16 to route messages to and from the field devices is transparent to host 12 . The address translation and inclusion of both the wireless address and the field device address in the wireless message allows multiple field devices associated with a single node (i.e. a single wireless address) to be addressed individually.
Although embedding the field device address in the payload of the wireless message as part of the control message is simple and effective, the field device address could be contained separately in the payload or elsewhere in the wireless message, if desired.
The presence of wireless network 16 is also made transparent to host computer 12 by decoupling the transmission of messages to field devices between host computer 12 and wireless network 16 . Gateway 18 monitors the state of wireless network 16 , and factors that can affect the response time to a message. By providing an estimated response time to messages being sent by host computer 12 , gateway 18 allows host computer 12 to treat what field devices FD 1 -FD 9 and wireless network 16 as if they were available on demand, even though network 16 and field devices FD 1 -FD 9 are often in a low power sleep state.
By micro-managing the On/Off status of individual field devices and individual nodes, only those field devices and nodes that are required for a particular communication with the host remain On until the communication is complete. This reduces power consumption by nodes and field devices that are not involved in the communication, and makes the communication with the host more efficient since the nodes and field devices do not cycle On and Off in the midst of the communication with the host.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, control system 10 is illustrated with six nodes and nine field devices, but other configurations with fewer or greater numbers of nodes and field devices are equally applicable. | A wireless mesh network routes messages between a host computer and a plurality of field devices. The mesh network is synchronized to a global regular active schedule that defines active periods when messages can be transmitted or received by nodes of the network, and inactive periods when messages cannot be transmitted or received. Based upon messages to be sent by the host computer to selected field devices, the network is controlled to selectively maintain active those nodes required to route messages to the selected field devices. Those required nodes are maintained in an active state as long as communication with the selected field devices continues, while other nodes are allowed to return to a low power inactive state. When communication between the host computer and the selected field devices is no longer required, the entire network is allowed to enter the low power inactive state. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of pending International patent application PCT/FR2006/002478 filed on Nov. 7, 2006 which designates the United States and claims priority from French patent application 0553478 filed on Nov. 16, 2005, the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention concerns an actuation and dispensing head intended to equip a pump and more particularly a pump for a dispenser of liquid products such as cosmetics, perfumes or medicines.
BACKGROUND OF THE INVENTION
Traditional dispensers encounter problems of sealing in particular as regards the pump chamber which contains the measures of product to be delivered.
This chamber opens to the outside via an outlet duct extended by an ejection channel provided in the pump actuation head and which is generally closed off by a so-called end check valve.
Another problem lies in the incompatibility of certain products with metals which prohibits any contact with the pump return spring.
Furthermore, the dispensing method is often poorly controlled which is detrimental to the measuring out of the product in particular when the volumes to be delivered are small (a few tens of microliters).
Moreover, there are difficulties in manufacture and assembly of the various constituent parts of the dispenser.
This problem arises, in particular, for the elements of the pump contributing towards sealing whereof the fineness and positioning are a determining factor for the production of a reliable and efficient dispenser, and for the constituent elements of the head which comprise principally a body in which the final ejection channel for the product is provided.
The aim of the present invention is to satisfactorily solve the problems posed by the prior art by providing sealing means additional to those of the dispenser at the level of the ejection duct of the pump actuation head.
SUMMARY OF THE INVENTION
This objective is achieved, according to the invention, by means of a head where said valve comprises a sealing needle movable translationally in said channel and articulated on a drive link connected to an axial rod sliding in said pump outlet duct.
According to an advantageous characteristic, said needle is articulated on said link by means of a deformable connecting band.
According to another characteristic, said link is connected laterally to said body by a hinge.
According to yet another characteristic, said needle is secured laterally by a set of elastic strips whereof the free ends are fixed to the body.
According to a first variant, said link consists of a cam with triangular cross-section articulated by its corner on a bevelled part of the needle.
According to another variant, said head moreover comprises a cover topping said body and closing said ejection channel in the upper part.
Preferably, said cover comprises a lateral aperture delimiting the end of said channel and whereof the internal circumference is capable of receiving the sealed pressing of the needle in the closing-off position.
Advantageously, said channel is provided with deformable upper lips allowing the latching of the needle.
According to a first variant, said link is extended by a transmission element consisting of a radial tab resting, without coupling, on the upper end of said rod.
According to an alternative variant, said rod is, this time, coupled to said link via a transmission element that is at least partially deformable.
In this case, said rod can be made in a single piece with the body and the link or else in the form of an added-on piece and said transmission element then comprises a coupling member cooperating by locking with an anchoring member disposed at the upper end of said rod.
According to another characteristic, said rod is provided with a lateral lug cooperating with a retaining notch provided on the internal wall of the outlet duct.
According to a specific variant, said rod has a diameter substantially equal to the internal diameter of the outlet duct, delimiting with the wall thereof a longitudinal passage for the product.
By virtue of its retractable needle, the head of the invention provides automatic sealing of the dispenser.
The sealing is, moreover, reinforced and made secure by the action of the elastic strips which, in the rest position of the head, provide the forced pressing of the needle against the output aperture of the ejection channel.
As for the link and the rod, these make it possible to split the product dispensing method that takes place in this way into two times which allows better control of the measuring out.
Moreover, the body of the head can be made in a single piece by injection moulding.
Finally, this head provides a high rate of retrieval of the product.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will emerge in the course of the following description, given with reference to the accompanying drawings, in which:
FIGS. 1A to 1C depict partial views of one embodiment of the head of the invention, respectively in axial section of the body before mounting, in a view from above of the body with a horizontal section of the cover and in a view from below of the body before mounting and without the cover;
FIGS. 2A to 2D depict sectional views of a pump equipped with a variant of the head of the invention in various positions;
FIGS. 3 , 4 and 5 depict sectional views of a pump equipped respectively with three other variant embodiments of the head of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The head of the invention forms a pushbutton intended to equip a pump P for a dispenser of liquid products.
This head is therefore intended to cooperate with the mechanism of the pump P and in particular the return spring S which is depicted in FIGS. 2A to 2D and the following ones, and the outlet duct E sometimes made in the form of a tube referred to as a nozzle.
The head of the invention, as depicted in particular in FIGS. 1A to 1C , comprises a cylindrical body 1 supporting a closing-off needle 2 forming a valve for the product output aperture and a cover or cap C ( FIG. 2A ) topping and covering said body.
If applicable, in order to reinforce the sealing, the internal circumference of the output aperture will be provided with an annular ring (not depicted) forming a valve seat for the end of the needle 2 .
The cover C is, for example, latched or fitted on the body 1 (as in the variant depicted here in the figures).
As depicted in FIG. 1B , the needle 2 is intended to fit into a discharge channel 12 provided here on the upper face of the body 1 after lowering and latching from the deployed mould output position of FIG. 1A , the device being made here in a single piece.
The channel 12 has, in its upper part, radially projecting deformable lips 12 a which partially close up the channel and hold the needle 2 in its housing whilst the cover C comes to close the upper part of the channel 12 .
The cover C comprises a lateral aperture delimiting the end of the channel 12 and the boundaries of its output aperture 50 whereof the internal circumference is capable of receiving the sealed pressing of the needle 2 in the closing-off position.
In the operating position ( FIG. 1B ), the needle 2 is retractable translationally into the channel 12 , by manual pressure on the cover C topping the body 1 and joint compression of the spring S (see FIGS. 2A to 2D ).
To that end, the needle 2 is articulated on a drive link 3 connected to an axial guide rod 4 which is cable of sliding, in the manner of a piston, in the outlet duct E of the pump P during dispensing of the product (see FIG. 2B ).
The link 3 consists of a cam with triangular cross-section connected by its corners, in the central bottom part, to the rod 4 via a transmission element 33 , and, in the lateral bottom part, to the body 1 via an elastic hinge 31 .
In the top part, the link 3 is articulated on a bevelled end 21 of the needle 2 via a deformable connecting band 32 . The link 3 thus has an axis of pivot with each adjacent element.
The thin connecting band 32 allows in particular the lowering of the needle 2 into the position of FIG. 1B from the position of FIG. 1A which corresponds to the output from the manufacturing mould.
The rod 4 is inserted with freedom to slide in the duct E and has a longitudinal flat section 40 (see FIGS. 2A to 2D and 3 ) or a longitudinal groove (not depicted) allowing the passage of the product through said duct and in the direction of the channel 12 since the rod 4 has here a diameter substantially equal to the internal diameter of the outlet duct E.
The rod 4 is also provided with a lateral lug 41 cooperating with a retaining notch e provided on the internal wall of the duct E.
During mounting of the body 1 on the pump P, the rod 4 enters the duct E and the lug 41 comes to latch under the notch e.
The duct E communicates with the channel 12 via a measuring-out chamber 10 delimited inside the body 1 and extending coaxially with said duct.
In order to perfect the sealing of the chamber 10 forming the piston cylinder, the upper edge of the duct E will advantageously be provided with a peripheral lip L ( FIGS. 2C , 2 D and 3 ) in dynamic contact with the wall of the body 1 .
The needle 2 is secured laterally to a set of two elastic strips 21 a , 21 b whereof the free ends are fixed to the body 1 by clamping in slots 20 a , 20 b , after lowering of the needle (see FIG. 1B ). The strips 21 a , 21 b contribute towards the return, guidance and then holding of the needle in the position of closing off the channel 12 .
In the embodiments of FIGS. 1A , 2 A, 3 and 4 , the rod 4 is coupled to the link 3 via a transmission element 33 that is at least partially deformable.
In the variants of FIGS. 1A and 2A , the rod 4 is moreover made in a single piece with the body 1 and the link 3 .
On the other hand, in the variants of FIGS. 3 and 4 , the rod 4 is made in the form of an added-on piece and, in the specific variant of FIG. 5 , the link 3 is extended by a transmission element 33 consisting of a radial tab resting, in this case by contact and without coupling, on the upper end of the rod 4 .
In FIGS. 3 and 4 , the transmission element 33 comprises a specific coupling member 34 cooperating by locking with an anchoring member 43 disposed at the upper end of the rod 4 .
In FIG. 3 , the coupling member 34 consists of a flexible washer through which the anchoring member in the form of a lug secured to the rod 4 is forcibly introduced.
In FIG. 4 , the coupling member 34 consists of a lug forcibly introduced into the anchoring member formed from a cavity provided at the top of the rod 4 .
The operation of the head will now be described with reference to FIGS. 2A to 2D where the liquid product appears in a dark colour.
In FIG. 2A , the pump is depicted after priming and the head has therefore previously been filled with product.
FIGS. 2C and 2D which depict the return of the head to the rest position are also applicable to the priming phase.
In the rest position depicted in FIG. 2A , the end of the needle 2 is pressed towards the front against the aperture 50 in the cover C, under the action of both the elastic strips 21 a , 21 b and the spring S which is under slight tension, thus hermetically closing off the channel 12 and, more generally, the pump P and the associated dispenser in its entirety.
In parallel, whilst the body 1 is pushed away upwards, the rod 4 is pulled downwards in the duct E by the retaining notch e and contributes towards the rotational torque to which the link 3 and its various articulations are subjected in the clockwise direction, thus reinforcing the action of the needle 2 .
The position depicted in FIG. 2B corresponds to the start of the product dispensing phase, the head beginning its descent in response to the manual pressure exerted vertically by the consumer on the cover C as represented by the arrow.
During this phase, the rod 4 remains substantially immobile in the duct E on account of the inevitable friction accompanying its sliding fitting in the duct E.
As for the body 1 , this begins its descent by compressing the spring S and subjecting the link 3 to a rotational torque in the anticlockwise direction. This movement brings about the translational movement towards the rear of the needle 2 and its retreat with respect to the ejection aperture 50 .
In parallel, the measuring-out chamber 10 empties progressively through the compression effect resulting from the relative movement of body and duct in the manner of a piston and the scraping of its wall by the lip L of the duct E thus causing a start of delivery of the product via the channel 12 and the aperture 50 .
The pressure on the head being maintained, the movement continues and the link 3 comes into abutment against the bevelled end 21 of the needle 2 , as depicted in FIG. 2C .
Then, the upper end of the rod 4 comes into abutment against the needle 2 and the travel of the needle is then at its maximum whilst the chamber 10 continues to empty.
As a result of the continuation of the pressing forces on the head, the rod 4 starts sliding downwards in the duct E of the pump, whilst the link 3 remains in abutment against the needle 2 . The measuring out ends when the bottom part of the body 1 reaches the lower shoulder of the pump P or when the upper edge of the duct E comes into abutment against the hinge 31 of the link 3 ( FIG. 2C ).
FIG. 2D corresponds to the phase of return of the head to the rest position of FIG. 2A .
Release of the manual pressure brings about relaxation of the spring S. This relaxation first causes ascent of the body 1 and pivoting of the link 3 in the clockwise direction until the needle 2 comes back into abutment against the aperture 50 , the rod 4 remaining immobilised in the duct E.
This movement is accompanied by the intake of product into the chamber 10 here via the inlet ball valve and progressive filling of the chamber in the internal volume of the body 1 .
Then the friction of the rod 4 in the duct is overcome and the rod 4 rises again until its lug 41 comes into abutment against the notch e of the duct E, the needle being held pressed against the aperture 50 by virtue of the action of the elastic strips 21 a , 21 b.
The spring S is then kept under slight tension by the early bringing into abutment of the facing parts of the body 1 and the duct E. | A triggering and dispensing head to be mounted on a pump for a liquid product dispenser provided with an exhaust conduit wherein the head has a body provided with an ejection channel closable by a flap which has a center punch translationally displaceable in the channel and hingeable about a drive billet connected to an axial rod sliding in the exhaust conduit. | 1 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to toilet systems having removable waste holding tanks and in particular to a pressure relief vent for relieving internal pressure build-up within the waste holding tank.
Toilet systems have been developed in which a toilet bowl is removably coupled to a waste holding tank. Waste from the toilet bowl is flushed into the holding tank for storage until disposal at a later time. When the holding tank is filled with waste, it is removed from the bowl and carried to a disposal site where the contents are dumped from the tank.
Such a toilet system can be integrally formed in a recreational vehicle as shown in Assignee's U.S. Pat. No. 4,776,631. Alternatively, the toilet system can be a two-piece portable toilet such as that disclosed in Assignee's U.S. Pat. No. 4,145,773. These patents are hereby incorporated by reference.
The removable waste holding tanks disclosed in the above referenced patents include an inlet port through which waste enters the tank from the toilet bowl. The inlet port is equipped with a valve for closing the port when the toilet is not in use and for opening the port when waste is to be flushed from the toilet into the holding tank. The valve includes an appropriate seal to prevent the escape of odors from the tank and to prevent leakage during handling of the portable tank.
Once waste has accumulated in the holding tank, biological processes take place in the tank to begin the breakdown of the waste. These processes result in the production of vapor within the holding tank, increasing the tank pressure. The pressure within the holding tank may also deviate from the ambient pressure for various other reasons, such as travel to a higher altitude.
A pressure within the tank greater than the ambient pressure can create problems for the user of the toilet. For example, if a liquid, such as a chemical deodorant is introduced into the toilet bowl for flushing into the holding tank, a jet-like gas discharge from the holding tank through the liquid in the bowl may occur as the inlet port valve is initially opened, causing an upward spray of the liquid.
One solution to the problem of pressure build-up within the holding tank is to equip the tank with a vent that is operably coupled to the inlet port valve to open the vent before the tank inlet port is opened. Such a vent arrangement is shown in U.S. Pat. No. 4,776,631 referred to above. While in principal such a vent will relieve pressure from within the holding tank, in practice, insufficient venting often occurs before the inlet port is opened. This is due in part to the speed employed by the operator in opening the tank inlet port. Insufficient venting can result in the same problems encountered with an unvented tank.
Accordingly, it is one object of the present invention to provide an improved vent for a portable waste holding tank.
It is a further object of the present invention to provide a vent for a portable waste holding tank which is only operable to vent the tank when the tank is operatively coupled to the toilet bowl and not while the tank is being transported to a disposal site.
It is yet another object of the present invention to provide a waste holding tank vent that is normally closed to prevent diffusion of odors from the tank into the area surrounding the tank but which will operate to open and relieve small amounts of excess pressure as the pressure is generated.
The vent assembly of the present invention includes a valve body installed in a vent port in the holding tank wall having a vent passage therein for airflow from the tank interior to atmosphere. The valve body includes an upper valve seat surrounding the vent passage at the upper end thereof and an upper valve member is positioned upon the upper valve seat, covering the passage to seal the interior of the holding tank from the surrounding atmosphere. The only force acting to hold the upper valve member on the upper valve seat is gravity. The upper valve member is sufficient to prevent diffusion from the tank.
The bottom surface of the upper valve member is communication with the interior of the holding tank while the top surface of the valve member is in communication with the atmosphere. When the internal pressure in the holding tank exceeds the ambient pressure by a predetermined amount, sufficient to overcome the gravitational force acting on the upper valve member, the internal pressure will lift the upper valve member off the upper valve seat, allowing gas to be vented from the interior of the holding tank. The upper valve member will return by gravity to the upper valve seat, closing the vent passage, when the tank pressure is sufficiently reduced. By constructing the upper valve member to be light weight, only a small amount of gas will be vented each time the upper valve member is removed from its valve seat.
A lower valve seat is formed at the base of the vent passage and a lower valve member is provided for engagement with the lower valve seat to close the vent passage from the tank interior. The lower valve member is held in a closed, sealed position by a biasing spring. A release button is provided for opening the lower valve. The button is depressed by a cam on an upper portion of the toilet system containing the toilet bowl. When the tank is coupled with the toilet bowl, the release button is automatically depressed by the cam, opening the lower valve. The lower valve thus serves to seal the tank when the tank has been removed from the toilet bowl for dumping of its waste contents.
The lower valve member is also provided with a floatation device to raise the lower valve member against the lower valve seat if the tank is overfilled. This prevents spillage of waste through the vent assembly due to overfilling or splashing of the waste contents.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a representative recreational vehicle with a toilet system containing the vent assembly of the present invention;
FIG. 2 is a fragmentary perspective view showing the toilet system and its waste holding tank;
FIG. 3 is a sectional view of the toilet bowl, and holding tank coupling;
FIG. 4 is a sectional view of the vent assembly of the present invention as seen substantially from the line 4--4 of FIG. 5 showing the vent assembly closed;
FIG. 5 is a sectional view of the vent assembly of the present invention as seen substantially the lines 5--5 of FIG. 4 showing the vent assembly open; and
FIG. 6 is an exploded perspective view of the coupling between the lower valve member stem and the vent assembly release button.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a representative recreational vehicle (RV) 20 containing a toilet system which includes the vent of the present invention. RV 20 comprises a wheeled chassis 22 upon which is supported the RV body 24. Body 24 in general includes a floor 34, a vertical side 36 and a roof 38 forming an enclosure. Side 36 includes four side walls, namely a front wall 36a, a rear wall 36b and two lateral side walls 36c. It is one of these lateral side walls 36c which is viewed directly in FIG. 1. Side wall 36c is provided with a rectangular opening 40 which is shown in FIG. 1 to be closed by a door 42.
Referring now to FIG. 2, the RV contains a water use sanitary toilet 44. The toilet 44 includes an upper portion 46 containing a toilet bowl 48. The toilet 44 further includes a portable waste holding tank 50, which is insertable into the RV body through the opening 40 when the door 42 has been opened. The holding tank 50 includes a top wall 52 having an inlet port 54 therethrough for passage of waste from the toilet bowl 48 into the holding tank. As the tank 50 is moved into the compartment beneath the toilet bowl, guide members 56 on each side of the inlet port 54 and parallel to the direct]on of tank motion, guide the inlet port 54 into registry with the lower outlet 58 of the toilet bowl. The guide members 56 cooperate with annular flange 60 extending radially outwardly about the periphery of the bowl outlet. The inlet port 54 is formed by a seal 62 which seals against the lower edge of the annular flange 60 and against the upper surface of a closure member 64 for closing the inlet port.
The closure member 64 is selectively movable to a position opening the port 54 to enable waste to be flushed from the toilet bowl into the holding tank. When the holding tank is coupled to the toilet bowl, a flush valve actuator 66 on the tank is operatively coupled to a flush knob 68 on the upper portion 46 of toilet 44. Upon actuation of the flush knob 68, the actuator 66 operates to move the closure member 64 horizontally away from the port 54, enabling waste to flow from the bowl into the holding tank. As the closure member 64 is moved to an open position, if the internal pressure within the holding tank is greater than the ambient pressure, the release of this internal pressure can cause the waste or other liquid in the bowl, above the closure member 64, to spray upwardly from the toilet bowl. In order to properly vent the holding tank, the tank is equipped with a vent assembly 70 of the present invention, mounted in an opening in the top wall 52 of the holding tank.
The vent assembly 70 is shown in greater detail in FIGS. 4 and 5. Vent assembly 70 is installed within a recessed aperture 72 in the tank top wall 52. The vent assembly 70 includes a vent body 74 constructed of an upper portion 76 and a lower portion 78 joined together at 80 by sonic welding, adhesive, etc. The vent assembly is installed and held within the aperture 72 by circumferentially spaced lobes 82 which fit beneath the periphery of aperture 72 through corresponding spaced cut outs 84 in the periphery of the aperture. O-ring 86 provides a seal between the vent body 74 and the tank top wall 52. Annular flange 88 seats upon the ledge 90 of the top wall to vertically support the vent assembly.
The vent body 74 forms a generally annular vent passage 92 extending vertically for the passage of vapor from the tank interior to the exterior atmosphere. The upper end 94 of the vent passage has axially raised ridges 96 and 98 about the inner and outer peripheries of the passage 92. The raised ridges 96 and 98 form an upper valve seat.
The vent passage 92 is annular in shape formed by an inner cylindrical wall 100 and an outer cylindrical wall 102. The lower end of passage 92 is formed by the bottom 104 of the inner wall 100 and an annular seal 106 extending downward below the outer wall 102. The seal 106 forms a lower valve seat 108. A lower valve member 110 is engagable with the lower valve seat as shown in FIG. 4 to close the vent passage 92 from the tank interior. The lower valve member 110 thus operates as closure means for the passage 92 when the holding tank 50 is removed from the opening 40.
The lower valve member 110 includes a valve stem 112 which extends upwardly through the center of the vent body. The valve stem 112 is coupled to a release button 114 which includes a cap 116 at the upper end of the vent assembly. A biasing spring 118, positioned between a flange 120 of the button and a spring seat 122 in the vent body, operates to bias the button into a raised position in which the lower valve member is seated against the lower valve seat 108, sealing the vent passage 92 from the tank interior.
When the tank is coupled with the toilet bowl, a cam 124 extending downward from the upper portion of the toilet engages the cap 116, depressing the button 114. The cam 124 thus operates as a release means for the biasing spring 118 by overcoming the force of spring 118 on lower valve member 110 to allow the lower valve member 110 to drop away from the lower valve seat 108, opening the passage 92 to the tank interior. With reference to FIG. 6, the connection between the button core 126 and the valve stem 112 is shown in greater detail. The upper end 128 of stem 112 forms a generally T-shaped section having a pair of lower surfaces 130. The inner hollow cylinder of the button core 126 includes a pair of slots 132 each having a lower wall 134. The lower walls 134 engage the lower surfaces 130 of the valve stem upper end to vertically support the valve stem and lower valve member 110. When the spring 118 has urged the button upward, the valve stem and lower valve member are raised to close the lower end of the vent passage 92. However, when the button is depressed by the cam 124, the lower valve member 110 is allowed to drop by gravity to open the vent passage but the lower valve member is not forced down by operation of the button.
An annular upper valve member 136 is positioned around the button core 126 and rests upon the raised ridges 96 and 98 forming the upper valve seat. Vertical projections 138 circumferentially spaced around the upper valve member operate to hold the upper valve member in position during assembly of the vent prior to insertion of the button core. Once the button and button core have been installed, the upper valve member 136 will be restrained radially by the button core.
The upper valve member 136 is held upon the upper valve seat solely by the affect of gravity acting on the upper valve member. When the holding tank is coupled with the toilet and the lower end of the passage 92 is open, the lower surface 140 of the upper valve member is in communication with the interior of the holding tank. Conversely, the upper surface 142 of the upper valve member is in communication with the ambient atmosphere as shown by the arrow 143.
When the pressure within the holding tank exceeds the ambient pressure and produces an upward force on the upper valve member 136 greater than the gravitational force holding the upper valve member down, the pressure force will cause the valve member to raise toward an upper position shown in phantom lines in FIG. 5. In this position, gas is allowed to vent from the holding tank to relieve the internal pressure. Once the pressure has been reduced, the upper valve member will again drop by gravity onto the upper valve seat. When the upper valve member is seated on its valve seat, it will prevent diffusion of gas from the holding tank into the area surrounding the toilet. The pressure differential between the tank interior and the atmosphere necessary to raise the upper valve member is determined by the weight of the upper valve member and its exposed surface areas. The pressure differential necessary to lift the upper valve member will also affect the quantity of gas relieved from the tank each time the upper valve member is opened. The lower the necessary pressure differential, the less gas will be released.
The vent operates to avoid the build up of pressure within the holding tank while at the same time maintaining the tank substantially closed so that the odors within the tank do not permeate into the surrounding atmosphere. When the tank is disconnected from the toilet bowl and carried to a disposal facility, the vent will be closed automatically by the lower valve member 110 to prevent spillage of the tank contents during transport.
The lower valve member 110 is equipped with a float 144. The float will operate to raise the lower valve member 110 in the event the tank contents reach the level of the float 144. This results in closure of the vent assembly to prevent leakage due to overfilling or splashing of the tank contents.
While the vent assembly of the present invention has been disclosed and described in the context of a recreational vehicle sanitary toilet having a removable holding tank, it is readily apparent that any toilet system with a waste holding tank, such as a two-piece portable toilet having a removable holding tank, can utilize the vent of the present invention.
It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. | A vent for a removable toilet holding tank includes a valve member that is in communication with both the holding tank interior and the ambient atmosphere and is moved off its valve seat when the pressure within the holding tank exceeds the ambient pressure by an amount sufficient to overcome the force of gravity acting to hold the valve member against its valve seat. The vent further includes a second valve member which is operable to close the vent when the holding tank is removed from the toilet bowl thereby precluding spillage of the tank contents during handling of the tank when separated from the toilet bowl. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the invention are directed to preferentially delivering therapeutic gas to a patient. More particularly, the embodiments are directed to delivering therapeutic gas to one, a combination, or all of a patient's left naris, right naris and mouth selectively.
2. Background of the Invention
Patients with respiratory ailments may be required to breathe a therapeutic gas, such as oxygen. The therapeutic gas may be delivered to the patient from a therapeutic gas source by way of a nasal cannula.
Delivery of therapeutic gas to a patient may be continuous, or in a conserve mode. In continuous delivery, the therapeutic gas may be supplied at a constant flow throughout the patient's breathing cycle. A significant portion of the therapeutic gas provided in continuous delivery is wasted, i.e. the therapeutic gas delivered during exhalation of the patient is lost to atmosphere. In order to overcome the wastefulness of continuous delivery, related art devices may operate in conserve mode using a conserver system.
A conserver may be a device which senses a patient's inspiration, and delivers a bolus of therapeutic gas only during inspiration. By delivering therapeutic gas only during inspiration, the amount of therapeutic gas lost to atmosphere may be reduced. Conserver systems of the related art may sense a patient's inspiration at one naris and delivery the bolus of therapeutic gas to the other naris, such as through a bifurcated nasal cannula. Alternatively, conserver devices of the related art may sense a patient's inspiration at the nares generally, and delivery a bolus of therapeutic gas to the nares generally, such as through a non-bifurcated (single lumen) nasal cannula.
Sensing at one naris and delivering to a second naris may not work properly in all situations. If the patient has a blocked naris, e.g. because of congestion or some physical abnormality, either the sensing may not operate properly or the delivery of therapeutic gas may be to the blocked naris. Sensing and/or delivery may also fail to operate properly if the nasal cannula becomes dislodged, such as during sleep. Even if a nasal cannula stays properly on the patient and neither naris is blocked, delivering the patient's entire prescription of therapeutic gas through a single naris may cause nasal irritation.
When sensing inspiration by monitoring both nares simultaneously, congestion and/or abnormalities in the nares may cause the system to not sense properly. Moreover, when delivering therapeutic gas to the nares generally, such as through a single lumen cannula, congestion and/or physical abnormalities of the nares may affect the volume inhaled in each naris, wasting therapeutic gas in some cases and not providing sufficient therapeutic gas in other cases.
SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS
The problems noted above may be solved in large part by a method and system of individually sensing airflow of the breathing orifices of a patient, and preferentially delivering therapeutic gas to those breathing orifices. One exemplary embodiment may be a method comprising sensing airflow of a first and second breathing orifice of a patient, delivering therapeutic gas to the first breathing orifice in proportion to the airflow of the first breathing orifice, and delivering therapeutic gas to the second breathing orifice in proportion to the airflow of the second breathing orifice.
The disclosed devices and methods comprise a combination of features and advantages which enable it to overcome the deficiencies of the prior art devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
FIG. 1 illustrates a preferential delivery system in accordance with embodiments of the invention;
FIG. 2A illustrates, in shorthand notation, the system of FIG. 1 ;
FIG. 2B illustrates an alternative embodiment of the system of FIG. 1 ;
FIG. 2C illustrates yet another alternative embodiment of the system of FIG. 1 ;
FIG. 3 illustrates a preferential delivery system in accordance with alternative embodiments of the invention;
FIG. 4A illustrates, in shorthand notation, the system of FIG. 3 ;
FIG. 4B illustrates an alternative embodiment of the system of FIG. 3 ;
FIG. 4C illustrates yet another alternative embodiment of the system of FIG. 3 ; and
FIG. 5 illustrates an alternative embodiment of the system of FIG. 3 using fewer three-port valves.
NOTATION AND NOMENCLATURE
Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or direct electrical or mechanical connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a preferential delivery system 100 in accordance with at least some embodiments of the invention. The preferential delivery system 100 may be coupled to a therapeutic gas source 10 by way of a gas port 11 . The therapeutic gas source 10 may be any suitable source of therapeutic gas, such as a portable cylinder, an oxygen concentration system or a permanent supply system as in a hospital. The selective delivery system also couples to a patient (not shown) by any of a variety of devices and systems by way of a variety of ports, such as narial ports 23 , 25 and an oral port 27 . For example, the preferential delivery system 100 may couple to a patient's nares by way of a nasal cannula. In accordance with embodiments of the invention, the preferential delivery system 100 monitors patient breathing and selectively delivers therapeutic gas to a left naris (LN), right naris (RN) and/or to the mouth (M) of the patient.
In accordance with at least some embodiments, the preferential delivery system 100 comprises both electrical components and mechanical components. In order to differentiate between electrical connections and mechanical connections, FIG. 1 (and the remaining figures) illustrate electrical connections between components with dashed lines, and fluid connections, e.g. tubing connections between devices, with solid lines. The preferential delivery system 100 in accordance with at least some embodiments of the invention comprises a processor 12 . The processor 12 may be a microcontroller, and therefore the microcontroller may be integral with read-only memory (ROM) 14 , random access memory (RAM) 16 , a digital-to-analog converter (D/A) 18 , and an analog-to-digital converter (A/D) 20 . The processor 12 may further comprise communication logic 17 , which allows the system 100 to communicate with external devices, e.g., to transfer stored data about a patient's breathing patterns. Although a microcontroller may be preferred because of the integrated components, in alternative embodiments the processor 12 may be implemented by a stand-alone central processing unit in combination with individual RAM, ROM, communication D/A and A/D devices.
The ROM 14 may store instructions executable by the processor 12 . In particular, the ROM 14 may comprise a software program that implements the various embodiments of the invention discussed herein. The RAM 16 may be the working memory for the processor 12 , where data may be temporarily stored and from which instructions may be executed. Processor 12 may couple to other devices within the preferential delivery system by way of A/D converter 20 and D/A converter 18 .
Preferential delivery system 100 also comprises three-port valve 22 , three-port valve 24 , and three-port valve 26 . In accordance with embodiments of the invention, each of these three-port valves may be a five-volt solenoid operated valve that selectively fluidly couples one of two ports to a common port (labeled as C in the drawings). Three-port valves 22 , 24 and 26 may be Humprey Mini-Mizers having part No. D3061, such as may be available from the John Henry Foster Co., or equivalents. By selectively applying voltage on a digital output signal line coupled to the three-port valve 22 , the processor 12 may be able to: couple gas from the gas source 10 to the common port and therefore to the exemplary left naris; and couple the pressure sensor 28 to the common port and therefore the exemplary left naris. Likewise, the three-port valve 24 , under command of the processor 12 , may: couple gas from the gas source 10 to the narial port 23 and therefore the exemplary right naris; and couple the pressure sensor 30 to the narial port 23 and therefore the exemplary right naris. Further still, three-port valve 26 under command of the processor 12 , may: couple gas from the gas source 10 to the narial port 25 and therefore the patient's mouth; and couple the pressure sensor 32 to the narial port 25 and therefore the mouth. When the pressure sensors 28 , 30 and 32 are coupled to the respective ports, the processor 12 may read (through corresponding A/D converter 20 input signal lines) pressures indicative of airflow by the patient through the respective breathing orifice. Thus, the processor 12 may be able to determine when the patient is inhaling, and how much of the air drawn by the patient flows through each of the monitored breathing orifices.
Consider a situation where the preferential delivery system 100 couples to the nares of the patient by way of a bifurcated nasal cannula. As the patient inhales, outlet ports in the nasal cannula proximate to the openings of each naris experience a drop in pressure. The drop in pressure may be sensed through the nasal cannula and associated hosing by each of the pressure sensors 28 and 30 . Likewise, a sensing and delivery tube may be placed proximate to the patient's mouth, and thus pressure sensor 32 may detect an oral inspiration by the patient. In accordance with embodiments of the invention, the preferential delivery system 100 senses whether a patient has airflow through a monitored breathing orifice, and delivers therapeutic gas to the location or locations where the therapeutic gas may be inhaled by the patient.
Still considering the situation where the patient couples to the preferential delivery system 100 by way of a bifurcated nasal cannula and a separate sensing and delivery tube for the mouth, if there is no obstruction to inhalation in either of the nares or the mouth, therapeutic gas may be provided to any one or a combination of the nares and the mouth. Here, the preferential delivery system 100 may beneficially alternate the delivery site periodically so as to reduce discomfort associated with the therapeutic gas. Should the nasal cannula become partially dislodged, therapeutic gas may be provided only to the naris where the outlet port of the nasal cannula is still in operational relationship to the naris. Should the patient's nares become congested or blocked, therapeutic gas may be provided to the naris that is open.
The embodiments of the invention described above may work equally well in systems delivering a continuous flow of therapeutic gas, as well as systems operating in a conserve mode. In the continuous mode of operation, each of the three-port valves 22 , 24 and 26 may couple therapeutic gas to their respective breathing orifice for extended periods of time, e.g. several respiratory cycles. Periodically, therapeutic gas delivery may cease and the preferential delivery system 100 may monitor the breathing pattern of the patient. That is, one or more of the three-port valves 22 , 24 and 26 may change valve position, thus coupling pressure sensors to their respective breathing orifices and stopping therapeutic gas flow. If a monitored breath or breaths show that none of the possible breathing orifices are blocked, then the system 100 may simply switch back to the continuous mode of operation. If the preferential delivery system cannot detect an inhalation for any one of the breathing orifices, continuous flow mode may be resumed without providing therapeutic gas to the breathing orifice experiencing a problem.
In alternative embodiments, the preferential delivery system 100 may operate in a conserve mode, delivering a bolus of gas during each inhalation of the patient. Consider for purposes of explanation the left naris illustrated in FIG. 1 , as well as its associated three-port valve 22 and pressure sensor 28 . Prior to an inspiration, the three-port valve 22 may couple the pressure sensor to the common port of three-port valve 22 and therefore the left naris. As the patient starts an inhalation, as sensed by the pressure sensor 28 and read by processor 12 , the three-port valve 22 changes valve position (as commanded by processors 12 ) and couples the therapeutic gas source 10 to the common port (and effectively blocking the pressure sensor from the common port). For a period of time, e.g. 100 mili-seconds, therapeutic gas may flow to the exemplary left naris. When the desired bolus volume has been delivered, possibly as a function of flow rate of the therapeutic gas and time, the processor 12 may command the three-port valve 22 to its original state, again fluidly coupling the pressure sensor 28 to the left naris. During exhalation, again sensed by pressure sensor 28 , the three-port valve 22 remains in the valve position coupling the pressure sensor to the common port, and therefore no therapeutic gas is delivered. This exemplary process is equally applicable to three-port valve 24 and pressure sensor 30 in operational relationship to the right naris, as well as three-port valve 26 and pressure sensor 32 in operational relationship to the patient's mouth. Thus, in conserve mode, the preferential delivery system 100 may detect whether the nares and/or mouth are open to therapeutic gas flow with each inspiration. In the event an inspiration on any particular delivery path is not detected, indicating a blockage or other gas delivery problem (such as a dislodged cannula), the preferential delivery system 100 may refrain from providing therapeutic gas to that breathing orifice.
FIG. 2A illustrates the preferential delivery system 100 of FIG. 1 in a shorthand notation, showing only pressure sensors 28 , 30 and 32 coupled to the respective breathing orifices. FIG. 2B illustrates alternative embodiments of the invention monitoring and delivering therapeutic gas only to the nares of a patient. In the embodiments of FIG. 2B , if both the left naris and right naris are open to flow the preferential delivery system 100 may deliver therapeutic gas to either naris, to both nares, or in an alternating fashion. In the event that either the left or right naris become clogged or blocked, or if the sensing and delivery tubing (such as a nasal cannula) become dislodged, the preferential delivery system may provide therapeutic gas to the naris where airflow is sensed. FIG. 2C illustrates alternative embodiments of the invention where two pressure sensors are used, but in this case only one pressure sensor is associated with the nares, and the second pressure sensor is associated with the mouth. In the embodiments of FIG. 2C , a patient may utilize a single lumen cannula and a second sensing and delivery tube associated with the mouth. The preferential delivery system 100 may thus selectively provide therapeutic gas to the nares and/or to the mouth. In the event that either of the nares as a group or the mouth become blocked or otherwise unavailable for inspiration, the preferential delivery system 100 preferably provides therapeutic gas to the breathing orifice through which inhalation takes place.
FIG. 3 illustrates a preferential delivery system 102 constructed in accordance with alternative embodiments of the invention. Like the system of FIG. 1 , the preferential delivery system 102 comprises a processor 12 , possibly in the form of a microcontroller, comprising ROM 14 , RAM 16 , a D/A converter 18 and an A/D converter 20 . Rather than pressure sensors, the preferential delivery system 102 may use flow sensors 40 , 42 and 44 . Thus, the preferential delivery system 102 may sense a portion of the flow associated with each breathing orifice. Consider for purposes of explanation the flow sensor 40 and three-port valves 46 , 48 coupled to the left naris. Three-port valve 46 , under command of the processor 12 , may: couple the gas source 10 to the common port and therefore the exemplary left naris; and couple the flow sensor 40 to the common port and therefore the exemplary left naris. Thus, during a period of time when the preferential delivery system 102 provides therapeutic gas to the left naris (whether continuous or in a bolus form), the three-port valve 46 provides the therapeutic gas to the left naris and blocks the flow sensor. In a second valve position, the three-port valve 46 fluidly couples the flow sensor to the common port and therefore the exemplary left naris. However, and in accordance with embodiments of the invention, the flow sensor 40 may not be operational until gas can flow through the sensor. Three-port valve 48 , in a first valve position, couples the flow sensor 40 to an atmospheric vent (marked ATM in the drawing), thus allow gas to flow through the flow sensor for measurement purposes. The three-port valve 48 , in a second valve position, couples to a blocked port 49 . Consider for purposes of explanation a preferential delivery system 102 operating in a conserve mode, where a bolus of gas is provided to one or more breathing orifices during inspiration. After a bolus has been delivered, the three-port valve 46 (and possibly the three-port valves 50 and 54 ) may change valve positions, thus fluidly coupling the flow sensor 40 to the common port and the exemplary left naris. If the flow sensor 40 outlet is not blocked, a portion of the therapeutic gas may reverse flow through the flow sensor 40 and out the atmospheric vent. Three-port valve 48 (as well as corresponding three-port valves 52 and 56 ) may be used to temporarily block reverse flow and loss of therapeutic gas, i.e. the valves may remain in a position that blocks flow for about 300 milliseconds after therapeutic gas delivery has stopped by a change of valve position by upstream three-port valves 46 , 50 and 54 . After the expiration of the period of time of possible reverse flow has ended, one or more of the three-port valves 48 , 52 and 56 may change valve positions, thus allowing the flow sensors to sense airflow. The description with respect to the three-port valves 46 , 48 and flow sensor 40 for the left naris is equally applicable for the corresponding structures for the right naris and mouth.
FIG. 4A illustrates the preferential delivery system 102 of FIG. 3 in a shorthand notation, showing only flow sensors 40 , 42 and 44 coupled to their respective breathing orifice. FIG. 4B illustrates alternative embodiments of the invention where only a patient's nares are used for sensing and delivery. In the embodiments of FIG. 4B , if both the left naris and the right naris are open to flow, the preferential delivery system 102 may deliver therapeutic gas to either naris, to both nares, or in an alternating fashion. In the event that either the left or right naris become clogged or blocked, or if the sensing and delivery tubing become dislodged, the preferential delivery system may provide therapeutic gas only to the unblocked naris. FIG. 4C illustrates further alternative embodiments where two flow sensors are used, but in this case only one flow sensor is associated with the nares, and the second flow sensor associated with the mouth. In the embodiments of FIG. 4C , a patient may utilize a single lumen cannula, and a second sensing and delivery tube associated with the mouth. The preferential delivery system 100 may thus selectively provide therapeutic gas to the nares and/or the mouth. In the event that either of the nares as a group or the mouth become blocked or otherwise unavailable for inspiration, the preferential delivery system 102 preferably provides therapeutic gas to the open breathing orifice.
FIG. 5 illustrates alternative embodiments of the invention utilizing flow sensors, but reducing the number of three-port valves used. The electrical components have been omitted from FIG. 5 for purposes of clarity. In particular, FIG. 5 illustrates that the three three-port valves 48 , 52 and 56 of FIG. 3 may be replaced by a single three-port valve 58 . Blocking reverse flow through the flow sensors in the embodiments of FIG. 5 may be accomplished by single three-port valve 58 . Relatedly, opening the second port of each of the flow sensors to the atmosphere vent so that flow may be detected may likewise be accomplished with a single three-port valve 58 .
The embodiments discussed to this point control therapeutic gas flow in a boolean fashion. That is, therapeutic gas is either delivered to a breathing orifice, or the preferential delivery systems 100 , 102 refrain from delivering therapeutic gas to a breathing orifice. However, alternative embodiments of the invention, which may be implemented using any of the exemplary embodiments described above, may control flow to each breathing orifice in proportion (either direct or inverse) to the amount of airflow drawn by that breathing orifice. Consider, for purposes of explanation, the pressure and flow sensor embodiments illustrated by FIGS. 2B and 4B . For a variety of reasons, such as congestion, physical abnormalities, periodic swelling of the nasal tissue, and the like, the amount of air flow drawn by a patient during inhalation through the nares may not be equal. By detecting a pressure and/or detecting a portion of the air flow through each naris, the preferential delivery systems 100 , 102 may quantify the relationship between the air flow as between the nares. For example, the left naris of an exemplary patient may carry 20% of the airflow, and the right naris of a patient may carry the remaining 80% of the air flow. In the embodiments discussed above, therapeutic gas may only be delivered to the right naris, carrying the bulk of the airflow. In the alternative embodiments, the selective delivery systems 100 , 102 may proportion delivery of therapeutic gas. In the example of an 20–80 split between the left naris and the right naris respectively, the preferential delivery system 100 , 102 may correspondingly proportion therapeutic gas flow 20% to the left naris and 80% to the right naris, or vice-versa. As the patient's left naris becomes less congested (or the patient changes head position that affects air flow or swelling, the preferential delivery system may likewise change the proportion of therapeutic gas flow. Referring again to FIG. 3 , proportioning therapeutic gas flow may be accomplished by pulse width modulating each of the three-port valves 46 , 50 and 54 by the processor 12 . In an exemplary situation where a patient's left naris carries only 20% of the total airflow and control is a direct proportion, the electrical signal from the processor 12 to the three-port valve 46 may be pulse width modulating at a duty cycle where only 20% of the therapeutic gas is delivered to the left naris. Although the discussion with respect to the alternative embodiments where therapeutic gas may be proportioned between breathing orifices focused only on proportioning the nares, the proportioning may likewise be done between the nares in general and the mouth, or all three breathing orifices.
In all of the embodiments, in the event an inhalation is not detected through any breathing orifice, an alarm may be sounded. Relatedly, if the preferential delivery systems sense an apnea event, an alarm may be sounded. Moreover, the patient's breathing patterns may be stored, such as in RAM 16 , and communicated to external devices through communication port 17 .
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. For example, while the use of a cannula, at least with respect to coupling the preferential delivery system to the nares, has been discussed, this is only exemplary and any system and method by which the therapeutic gas is fluidly coupled from the preferential delivery system to the breathing orifices of the patient may be equivalently used. A single lumen cannula may be operable in some situations with respect to the nares. Likewise, a bifurcated nasal cannula may be used with respect to the nares. Alternatively, a cannula may be used where the sensing lines couple to the flow sensors are separate and distinct from the lines in which therapeutic gas is delivered proximate to the breathing orifices. Further, while the various embodiments described use electrical components as the control system, other pneumatic/mechanical systems may be equivalently used. It is intended that the following claims be interpreted to embrace all such variations and modifications. | Methods and related systems for individually sensing airflow in the breathing orifices of a patient, and preferentially delivering therapeutic gas to those breathing orifices based on the amount of airflow sensed. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a network system for data transmission wherein a plurality of stations, i.e., transmitters or receivers are connected via a data transmission bus line and a separate synchronous signal transmission bus line and a predetermined code string signal is supplied to each station so that a plurality of addresses changing sequentially at a predetermined frequency are allocated among the stations.
2. Description of the Prior Art
Japanese Patent Publication No. 52-13367 and corresponding U.S. Pat. No. 3,757,050 published on Sept. 4, 1973, to Masanori Mizote discloses a multichannel transmission system for producing, transmitting and receiving pulse signals assigned to corresponding signal channels and modulated for information conveyance, the disclosure of which is incorporated by reference.
FIG. 1 shows a block diagram of a conventional data transmission network system exemplified in the above-described U.S. Pat. No. 3,757,050. In FIG. 1, a plurality of pairs of transmission stations (or transmitters) 4 and reception stations (or receivers) 5 are connected via a synchronous signal transmission bus line 2 and a data transmission bus line 3. The synchronous signal transmission bus line 2 provides a means for conducting the synchronous signal shown in FIG. 2(c) from a synchronous signal generator 1 to each station. The synchronous signal generator 1 generates a clock pulse train having a constant period τ as shown in FIG. 2(a), an M-sequence code string repeating the order of H(1), H(1), H(1), L(0), L(0), H(1), L(0) at a constant period (T) as shown in (b) of FIG. 2, a pulsewidth-modulated signal as shown in (c) of FIG. 2.
Each transmission station 4 comprises: (a) a receiver circuit 6 which receives the above-described synchronous signal and demodulates the clock pulse train and M-sequence signal shown in FIG. 2; (b) shift registers 7, 8, and 9 which shift sequentially the bits of the demodulated M-sequence signal in synchronization with the clock pulses; and (c) a logic circuit 10 which opens a gate circuit 11 when a predetermined logical value results from a logical operation on the outputs of the shift registers 7, 8, and 9.
FIG. 3 shows a combination pattern of the logical outputs D 1 , D 2 , and D 3 of the shift registers 7, 8, and 9 in connection with the output X of the logic circuit 10 for each clock pulse of the clock pulse train signal. As seen from FIG. 3, seven different combinations of the levels "L" and "H" of the shift registers 7, 8, and 9 occur during the frequency period T of the above-described M-sequence signal.
Accordingly, if one of the seven combinations satisfies the logical condition of the logic circuit 10 in each transmission station 4 (for example, H, H, and L as shown in FIG. 3), the logic circuit 10 is activated once during each period T of the above-described M-sequence signal so that the gate circuit 11 is opened. Consequently, one bit of data is transmitted from an output circuit 12 to the data transmission bus line 3 at this time.
Similarly, each reception station or receiver 5 comprises a receiver circuit 13, shift registers 14, 15, and 16 and logic circuit 17. A gate 18 is opened only when a predetermined pattern is achieved during each period T of the above-described M-sequence signal so that a signal from the data transmission bus line 3 is received by an input circuit 19.
In this way, data transmission and reception are made possible between transmitters 4 and corresponding receivers 5 having logic circuits 10 and 17 which have the same logical condition.
Therefore, each pair of transmission and reception stations 4 and 5 can transfer data asynchronously with the remaining transmission and reception stations having different established conditions. Consequently, the transfer of data can be made without collision of data.
However, since only one bit of data can be transferred whenever each gate circuit 11 and 18 is opened in the conventional data transmission network system, the number of bits per frequency period of the above-described M-sequence signal must be increased. Therefore, the construction of the synchronous signal generator 1 becomes complicated and the number of stages of the shift registers in each station is increased accordingly, thus resulting in the increase of the cost and the reduction of processing speed.
In addition, the reliability of the network system is reduced since data transfer in units of one bit does not provide enough information to check for the occurrence of bit error.
SUMMARY OF THE INVENTION
With the above-described problems in mind, it is an object of the present invention to provide a reliable network data transmission system capable of transmitting and receiving a plurality of bits of data and capable of checking for the occurrence of bit error.
This can be achieved by providing a data transmission network system which delivers a predetermined M-sequence signal to each station via the synchronous signal transmission bus line and allocates a plurality of addresses changing sequentially at a predetermined frequency to each station, wherein each station comprises at least one of either means for serially transmitting a plurality of bits of data via the data transmission bus line or means for serially receiving a plurality of bits of data from the data transmission bus line.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be obtained from the following detailed description taken in conjunction with the attached drawings in which like reference numerals designate corresponding elements and in which:
FIG. 1 is a simplified block diagram of a conventional network system disclosed in U.S. Pat. No. 3,757,050;
FIG. 2 is a waveform pattern generated from a synchronous signal generator 1 shown in FIG. 1;
FIG. 3 is an explanatory diagram showing the change pattern of address obtained from the synchronous signal;
FIG. 4 is a simplified block diagram of a first preferred embodiment of a network system according to the present invention;
FIG. 5 is a timing chart of the main input/output waveforms for aid in explaining the operation of the system shown in FIG. 4; and
FIG. 6 is a simplified block diagram of an essential part of a second preferred embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will be made hereinafter to the drawings FIGS. 4 through 6 in order to facilitate understanding of the present invention.
FIG. 4 shows a first preferred embodiment according to the present invention. It should be noted that FIG. 4 shows the internal structure of one representative of the plurality of stations constituting the system. Since the other stations have the same internal structures, detailed description of other stations will not be given.
In the network system of this embodiment, the plurality of stations shown in FIG. 4 are connected via the synchronous signal transmission bus line 2 and data transmission bus line 3. The synchronous signal CM and the M-sequence code supplied to each station from the synchronous signal generator 1 shown in FIG. 1 have the same patterns as those shown in FIG. 2 and FIG. 3.
The receiver circuit 21 receives the synchronous signal CM from the synchronous signal transmission bus line 2 (the same signal pattern as those shown in (c) of FIG. 2) and separates the synchronous signal CM into the clock signal CLK shown in (a) of FIG. 2 and M-sequence code shown in (b) of FIG. 2, these separated signals being supplied to three stages of shift register 22. The shift register 22 outputs logical patterns D 1 , D 2 , and D 3 as shown in FIG. 3. The outputs D 1 , D 2 , and D 3 of the shift register 22 are supplied to a set of latches a, b, c and to a memory circuit 37 provided within a transmission/reception control circuitry 30. The memory circuit 37 stores data G 1 and G 2 used to control data transmission and reception to each address, the combination of "H"'s and "L"'s corresponding to each period T of the above-described M-sequence signal being allocated to one address.
A latch circuit 31 latches the output G 1 of the memory circuit 37 in synchronization with a clock signal CLK supplied from the receiver circuit 21. The latch circuit 31 comprises, for example, a D-type flip-flop. The output L 1 of the latch circuit 31 is supplied to a gate circuit A denoted by 33 and latches a, b, and c. Another latch circuit 32 serves to latch the output G 2 of the memory circuit 37 in synchronization with the above-described clock pulse train signal CLK and also comprises a D-type flip-flop. The output L 2 of the latch circuit 32 is supplied to a gate circuit C denoted by 35 via a gate circuit B denoted by 34 and parallelly via an inverter 36.
In addition, a transmitter circuit 40 comprises: (a) a memory circuit 44 holding a plurality of bits of data; (b) a parallel-to-serial data converter 43 which converts parallel data from the memory circuit 44 into a serial form; (c) a clock pulse generator 41 which supplies a clock signal of a predetermined period (<<T) to the parallel-to-serial data converter 43; and (d) a modulator 42 which modulates the pulsewidth of the clock pulse train signal generated by the clock generator 41 so as to correspond to the levels of "H" and "L" of the serial data from the parallel-to-serial data converter 43 (hereinafter denoted by "1" and "0"). The outputs La, Lb, and Lc of latches, a, b, and c are supplied to the memory circuit 44 as address data to elicit output of data stored in the address specified by the combination of the latch outputs La through Lc.
In addition, the receiver circuit 50 comprises: (a) a demodulator 51 which demodulates and separates data received data via the gate circuit C denoted by 35 into the clock pulse train signal and data signals; (b) a serial-to-parallel data converter (S/P converter) 52 which converts the modulated data into the parallel form; and (c) a memory circuit 53 storing the parallel data from the serial-to-parallel data converter 52.
The memory circuit 53 receives the outputs La, Lb and Lc of the latches a, b, and c as address data and loads data supplied from the above-described serial-to-parallel data converter 52 into a specified address.
The memory circuits 44 and 53 provided within the respective transmitter and receiver circuits 40 and 50 are connected to a microcomputer (not shown). The transmission data are written into the memory circuit 44 according to the state of a controlled load and the controlled load is controlled on the basis of data read from the memory circuit 53.
For example, in the above-described network system, data is stored as shown in FIG. 4 in the memory circuit 37 within the transmission/reception control circuit 30 of one of the plurality of stations constituting the network system. On the other hand, an area for data transmission and reception is provided in an address shown in FIG. 4 of the other memory circuits 44 and 53. In addition, the synchronous signal CM shown in FIG. 5 is supplied to each station and the outputs D 1 through D 3 of the shift register 22 in the station shown in FIG. 4 are <"1", "1", "1"> at time t 1 shown in FIG. 5.
As described above, since the outputs of the shift register 22 take a form of <"1", "1", "1">, the output G 1 of the memory circuit 37 turns to a "1" after a delay time t a and the other output G 2 turns to a "0". The delay time t a is the time required for the demodulation performed by the receiver circuit 21.
In the above-described state, the latch circuit 31 and latch circuit 32 receive the clock pulse signal CLK at the time t 2 after one period of the above-described synchronous signal CM has passed. The outputs G 1 and G 2 of the memory circuit 37 at time t 2 are latched. That is to say, the output L 1 of the latch circuit 31 turns to a "1" and output L 2 of the latch circuit 32 turns to a "0".
Simultaneously, the output L 1 of the latch circuit 31 is supplied to the latches a through c so that the outputs of the shift registers 22 in the form <"1", "1", "1"> at time of t 2 are latched. The latch outputs La through Lc are supplied to the memory circuits 44 and 53 as address data.
After the above-described operation is performed, the outputs D 3 through D 1 of the shift register 22 take the form <"1", "1", "0"> after the delay time t a has passed, thus turning the output G 1 of the memory circuit 37 to a "1" and output G 2 to a "1".
Therefore, the gate circuit A 33 is opened since the output L 1 of the above-described latch circuit 31 is turned to a "1" and the gate circuit C 35 is opened since the output L 2 of the latch circuit 32 is turned to a "0", so that the receiver circuit 50 is enabled to receive transmitted data. Therefore, the receiver circuit 50 receives serial data comprising a plurality of bits from the data transmission bus line 3 via the gate circuits A 33 and C 35. Thereafter, the input data is demodulated, converted into parallel data, and loaded into the memory circuit 53.
At this time, the memory circuit 53 receives <"1", "1", "1"> as address data and loads the received data into a memory cell corresponding to the address specified by <"1", "1", "1">.
Next, after another period of the above-described synchronous signal CM has passed and the time t 3 is reached, the outputs G 1 and G 2 of the memory circuit 37 are latched by means of the latch circuits 31 and 32. At this time, the above-described output G 1 is turned to a "1" and output G 2 is turned to a "1", so that the output L 1 of the latch circuit 31 is turned to a "1" and output L 2 of the latch circuit 32 is turned to a "1".
In this way, the gate circuit A 33 is opened, the gate circuit B 34 is opened, and the gate circuit C 35 is closed, so that the transmitter circuit 40 is enabled to transmit data.
On the other hand, the outputs La through Lc of the latches a through c are used to latch the outputs of the shift registers 22 in the form <"1", "1", "0"> at time t 3 and to supply them to the memory circuits 44 and 53.
The outputs D 3 through D 1 of the shift registers 22 take the form <"1", "0", "0">, having been shifted through one stage by the shift registers 22 after the delay time t a has passed after time t 3 and accordingly the output of the memory circuit 37 is updated.
Therefore, serial data comprising a plurality of bits is transmitted from the transmitter circuit 40 to the data transmission bus line 3 via the gate circuits A 33 and B 34 until one more period of the synchronous signal CM passes after time t 3 . At this time, the transmitted data within the area of the memory circuit 44 corresponding to the address data <"1", "1", "0"> is sent onto the bus 3.
As described above, in the station shown in FIG. 4, data can be received when the address is <"1", "1", "1"> and, on the other hand, data can be transmitted when the address is <"1", "1", "0">.
If the memory circuits 37, 44, and 58 are set in such a way that data is transmitted when the address is <"1", "1", "1"> in one of the other stations and data can be received when the address is <"1", "1", "0">, synchronization between this station and the station shown in FIG. 4 is achieved, allowing transmission and reception of data between the two stations.
Furthermore, if data is set in the memory circuit 37 of the station shown in FIG. 4 in such a way that data reception is enabled when the other address is, e.g., <0", "0", "1"> and data transmission is enabled when the address is <"0", "1", "0"> and in another station, data transmission is enabled when the address is <"0", "0", "1"> and data reception is enabled when the address is <"0", "1", "0">, the transmission and reception of data between these stations without collision is achieved.
In this way, the station shown in FIG. 4 can perform transmission and reception of data independently to and from the other two stations without collision of data.
Hence, as described above, if the data transmission and reception is mediated by an address common to the stations between which the transmission and reception of data are carried out, synchronous addressing with each other in accordance with the synchronous signal CM is facilitated.
Furthermore, one station can transmit and receive a plurality of different data to and from a plurality of stations, thus the system performance being improved remarkably.
On the other hand, since in the network system shown in FIG. 4, the transmitted and received data comprise a plurality of bits, the data can be checked for the occurrence of bit errors.
One example of a method of checking for the occurrence of a bit error is a parity-check method shown in FIG. 6.
As shown in FIG. 6, the transmitter circuit 40 is provided with a parity bit adding circuit 45 and the receiver circuit 50 is provided with a parity check circuit 54 and a parallel gate circuit 55.
Hence, during transmission of data, a plurality of bit-parallel data outputted by the memory circuit 44 are supplied to the parity bit adding circuit 45 and to the parallel-to-serial data converter 43 with a parity bit added.
During reception of data, the serial data to which the parity bit is added is received and supplied to the parity check circuit 54 via the demodulator 51 and serial-to-parallel data converter 52 in order to check for the presence of bit errors in the received data. If the received data contains no bit errors, the gate circuit 55 is opened to load the data into the memory circuit 53. If the received data contains a bit error, the gate circuit 55 is closed so that the erroneous data is inhibited from entering the memory circuit 53
It should be noted although in the embodiment shown in FIG. 4 the outputs of the shift registers 22 are supplied to the memory circuits 44 and 53 via the latches a through c, which delay the outputs of the shift register 22 by one period T of the synchronous signal CM, the outputs of the shift register 22 may alternatively be supplied to the memory circuit 44 and memory circuit 53 directly. In the latter case, a minimal delay time is required with respect to the pulses of the synchronous signal CM for timing the transmission or reception of data.
As described in detail above, the network system according to the present invention can transmit and receive a plurality of bits of data, thus, improving the reliability due to the capability of checking for the presence of bit errors.
In addition, since the number of bits of the M-sequence signal serving as a synchronous signal need not be increased even if the number of bits of data is increased, the structure of the code generator can be simplified and the processing speed can be increased.
It will be clearly understood by those skilled in the art that the foregoing description is made in terms of the preferred embodiments and various changes and modifications may be made without departing from the scope of the present invention, which is to be defined by the appended claims. | A data transmitting/receiving network system connects a plurality of stations via a data transmission bus line in a time sharing mode. A specially encoded clocking signal cycles through a plurality of unique states and each station is allowed to transmit/receive in one of the unique cycles. Each station is equipped with serial-to-parallel reception and parallel-to-serial transmission so that a plurality of bits can be transmitted/received in each cycle. Parity error checking is performed on the transmitted/received bit parcels. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a circuit arrangement for supplying a lamp, comprising a DC/AC converter for generating, from an input voltage, a high-frequency lamp current at a frequency f, and provided with
input terminals for connection to terminals of a power supply source supplying the input voltage,
a first branch interconnecting the input terminals and comprising a series arrangement of a first switching element and a second switching element,
a first control circuit coupled to a control electrode of the first switching element for rendering the first switching element conducting and non-conducting,
a second control circuit coupled to a control electrode of the second switching element and also coupled to a point P of the first control circuit for rendering the second switching element conducting dependent upon the voltage present at the point P, and
a load circuit shunting one of the switching elements and having terminals for connection of a lamp.
A circuit arrangement of this type is known from EP 0 294 878. In the known circuit arrangement, the first control circuit comprises a series arrangement of an inductive element L1 and a capacitive element C1, which series arrangement shunts a part of a ballast coil arranged in series with the lamp. The point P is constituted by a common point of the inductive element L1 and the capacitive element C1, and the second control circuit is connected to the point P via a diode. One end of the capacitive element C1 remote from the point P is connected to a common point A of the first and the second switching element of the first branch. Since the ballast coil conveys the lamp current during operation, alternating voltages of the frequency f are present both across the inductive element L1 and across the capacitive element C1. The AC voltage across the capacitive element C1 is used as a control signal for rendering the first switching element conducting and non-conducting. The control of the second switching element is derived from the control of the first switching element, i.e. the second switching element is rendered conducting when the voltage at the point P has reached a relatively low value. During normal operation of the circuit arrangement, this value is reached when the first switching element has been rendered non-conducting. The value of the voltage at the point P is determined by the voltage across the capacitive element C1 and the voltage at the point A. If the second control circuit is to function properly, it is necessary that the voltage at point A, after the first switching element has become non-conducting, decreases to a value which is equal to the voltage at the negative terminal of the power supply source, or is smaller than this voltage. However, practice has proved that, for example, in the case of a relatively low amplitude of the input voltage or in the case of the lamp having rectifying properties, the voltage at point A decreases to an insufficient extent, so that the second switching element is not rendered conducting and the DC/AC converter stops functioning.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a circuit arrangement in which the drawback described above is obviated.
According to the invention, a circuit arrangement of the type described in the opening paragraph is therefore characterized in that the DC/AC converter is also provided with a third control circuit for rendering the second switching element conducting during a time interval Δt1, which is smaller than 1/2f, after the first switching element has become non-conducting.
Since the third control circuit renders the second switching element conducting, a current can flow from the point A to the negative terminal of the power supply source, so that the voltage at point A decreases to the voltage which is present at this negative terminal. Since the voltage at point A has decreased to a sufficient extent, the second control circuit is capable of rendering the second switching element conducting in the next half cycle of the voltage at point A, so that the DC/AC converter continues to function, irrespective of, for example, the amplitude of the input voltage or the properties of the lamp fed by the circuit arrangement. The second switching element is rendered non-conducting by the second control circuit when the voltage at the point P reaches a higher value than the negative terminal of the power supply voltage. It should be prevented that both switching elements are conducting simultaneously. For this reason, it is necessary that the third control circuit does not render the second switching element conducting any longer when the second control circuit renders the second switching element non-conducting. In other words, the time interval Δt1 during which the third control circuit renders the second switching element conducting must be smaller than 1/2f.
Satisfactory results were found with embodiments of a circuit arrangement according to the invention in which the second control circuit is coupled to the point P via a unidirectional element, preferably a diode. The coupling between the first and the second control circuit is thus realized in a relatively simple and effective way. More particularly, satisfactory results were obtained if the circuit arrangement comprises a comparator, with respective inputs of the comparator being coupled to the control electrode and a main electrode of the first switching element, and with an output of the comparator being coupled to the unidirectional element.
The third control circuit preferably comprises a circuit section I for detecting a decrease of the voltage at a point A between the two switching elements of the first branch. Since a decrease of the voltage at point A is caused by the fact that the first switching element becomes non-conducting, the circuit section I indirectly detects that the first switching element has been rendered non-conducting so that the third control circuit can render the second switching element conducting when a voltage decrease of the voltage at point A is detected. It was found that a third control circuit comprising such a circuit section I functions in a very reliable manner.
Satisfactory results were found with embodiments of the third control circuit comprising a monostable multivibrator. This monostable multivibrator produces a control pulse having a relatively long period whenever the first switching element has become non-conducting. By means of this control pulse, the third control circuit renders the second switching element conducting for only a limited period of time in each high-frequency period. This limited period of time may be chosen to be such that the second switching element is conducting for a sufficiently long time to cause the voltage at point A to decrease to the desired level, while it is also prevented that the third control circuit still renders the second switching element conducting when the second control circuit renders the second switching element non-conducting.
Satisfactory results were also found with embodiments of the third control circuit, in which the circuit arrangement comprises a circuit section DR coupled to the second control circuit, the third control circuit and the control electrode of the second switching element for rendering the second switching element conducting in a delayed manner via the third control circuit and for rendering the second switching element conducting in an undelayed manner via the second control circuit. It was found that due to this delayed switching of the second switching element via the third control circuit, the risk that the two switching elements are rendered conducting simultaneously, for example, due to specific properties of the lamp, decreases considerably.
The first control circuit preferably comprises an inductive element and a capacitive element.
These and other aspects of the invention will become apparent from and will be elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWING
In the drawings:
FIG. 1 shows an embodiment of a circuit arrangement according to the invention, with a discharge lamp 1 connected thereto;
FIG. 2 shows a first embodiment of a third control circuit and a second control circuit as may be used in a circuit arrangement according to the invention, as shown in FIG. 1;
FIG. 3 shows a second embodiment of a third control circuit and a second control circuit as, may be used in a circuit arrangement according to the invention, as shown in FIG. 1;
FIGS. 4 and 5 show parts of the embodiment of FIGS. 2 and 3 in greater detail;
FIG. 6 shows an embodiment of a third control circuit, a second control circuit and a circuit section DR as may be used in a circuit arrangement according to the invention, and
FIG. 7 shows the circuit section DR of the embodiment of FIG. 6 in greater detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, the reference numerals 12 and 13 denote terminals for connection to terminals of an AC voltage source. Input terminals 12 and 13 are connected by means of a series arrangement of a fusistor 14 and a capacitor 16. Respective terminals of capacitor 16 are connected to respective inputs of a diode bridge 15. A first output of diode bridge 15 is connected to a second output by means of a capacitor 17. Capacitor 17 is shunted by a series arrangement of a coil 18, a capacitor 4 and a capacitor 11. A common point C of coil 18 and capacitor 4 constitutes a first input terminal in this embodiment. A second input terminal D is constituted by a common point of capacitor 17 and capacitor 11. Together with terminals 12 and 13, fusistor 14, capacitors 16 and 17, coil 18 and diode bridge 15, the AC voltage source constitutes a power supply source which supplies an input voltage. Coil 18 and capacitor 16 function as a filter. Input terminals C and D are interconnected by means of a first branch which is constituted by a series arrangement of a first switching element 7 and a second switching element 6. A common point B of capacitors 4 and 11 is connected to a common point A of the first and the second switching element by means of a series arrangement of terminal K1, a first electrode 2 of discharge lamp 1, capacitor 37, a second electrode 3 of lamp 1, terminal K2 and ballast coil 5. Together with capacitor 11, this series arrangement constitutes a load circuit. Terminals K1 and K2 are terminals for connection of a lamp. A part 21 of the ballast coil 5 is shunted by a series arrangement of coil 19 and capacitor 20. Coil 19 is shunted by a series arrangement of ohmic resistor 28 and zener diodes 29 and 30. P is a common point of coil 19 and capacitor 20. Capacitor 20 is shunted by a series arrangement of ohmic resistor 25 and zener diodes 26 and 27. A common point of ohmic resistor 25 and zener diode 26 is connected to a control electrode of the first switching element 7. The part 21 of ballast coil 5, coil 19, capacitor 20, ohmic resistors 25 and 28 and zener diodes 26, 27, 29 and 30 jointly constitute a first control circuit for rendering the first switching element conducting and non-conducting. The series arrangement of zener diodes 29 and 30 limits the voltage across coil 19 during operation of the circuit arrangement. Ohmic resistor 28 is used for optimizing the phase difference between the current in the load circuit and the control signal generated by the first control circuit. The series arrangement of zener diodes 26 and 27 limits the voltage between the control electrode and a main electrode of the first switching element during operation of the circuit arrangement.
Circuit section SC2 constitutes a second control circuit for rendering the second switching element conducting and non-conducting. An input of circuit section SC2 is connected to the point P via diode D1. An output of circuit section SC2 is connected to a control electrode of switching element 6. Circuit section SC3 constitutes a third control circuit for rendering the second switching element conducting during a time interval Δt1, which is shorter than 1/2f, after the first switching element has become non-conducting. The third control circuit SC3 comprises a circuit section I for detecting a decrease of the voltage at point A. An output of SC3 is connected to the control electrode of the second switching element. An input of SC3 is connected to the point A.
The circuit arrangement shown in FIG. 1 operates as follows.
If terminals 12 and 13 are connected to the terminals of an AC voltage source, an AC voltage supplied by the AC voltage source is rectified, and a DC voltage constituting the input voltage supplied by the power supply source is present between input terminals C and D. The first and the second control circuit render the first and the second switching element high-frequency conducting and non-conducting, respectively. As a result, a high-frequency AC current with which the lamp 1 is fed flows through the load circuit. This high-frequency current causes a high-frequency AC voltage across part 21 of ballast coil 5. As a result, high-frequency AC voltages are also present across coil 19 and capacitor 20. The high-frequency AC voltage across capacitor 20 renders the first switching element conducting if the voltage at point P is higher than the voltage at point A. If the voltage at point P is lower than that at point A, the high-frequency voltage across capacitor 20 renders the first switching element non-conducting. If the first switching element is conducting, the voltage at point A is substantially equal to that at input terminal C. The voltage at point P is higher than the voltage at point A and thus also higher than the voltage at input terminal D. In this situation, the diode D1 is non-conducting, and the non-conducting state of the second switching element is maintained by the second control circuit SC2. When subsequently the polarity of the high-frequency AC voltage across capacitor 20 changes and the voltage at point P becomes lower than the voltage at point A, the first switching element is rendered non-conducting. Due to the action of the ballast coil 5, the current through this ballast coil generally continues to flow from A to B immediately after the first switching element has become non-conducting. A diode junction which forms part of the second switching element conveys current from input terminal D to point A during this phase of operation. This action of the ballast coil and the diode junction of the second switching element is sufficient in many practical circumstances to render the voltage at point A substantially equal to that at input terminal D after the first switching element has become non-conducting. However, in some cases, for example, when the amplitude of the input voltage is relatively low or when the lamp has rectifying properties, the ballast coil and the diode junction are not capable of causing the voltage at point A to decrease to a sufficient extent. However, in the circuit arrangement shown in FIG. 1, the circuit section I which forms a part of the third control circuit detects a decrease of the voltage at point A which results from the fact that the first switching element has become non-conducting. The third control circuit SC3 subsequently renders the second switching element conducting so that the voltage at point A becomes substantially equal to the voltage at input terminal D (also if the ballast coil and the diode junction in the second switching element are not capable of realizing this). Since the voltage at point P becomes lower than that at point A in this phase of operation of the circuit arrangement, this voltage also becomes lower than the voltage at input terminal D. As a result, the diode D1 conveys current and the second control circuit SC2 renders the second switching element conducting. Upon a subsequent change of the bias of the high-frequency voltage across capacitor 20, at which the voltage at point P increases with respect to the voltage at point A, diode D1 will no longer convey current so that the second switching element is rendered non-conducting, whereafter the first switching element is rendered conducting again upon a further increase of the voltage at point P.
In FIG. 2, the third control circuit SC3 is constituted by circuit section I', capacitor C1, amplifier I2, monostable multivibrator MMV, NOR-gate NOR and amplifier I3. Circuit section I' and capacitor C1 jointly constitute a circuit section I for detecting a decrease of the voltage at point A. Circuit section II', amplifier I1, AND-gate AND, NOR-gate NOR and amplifier I3 jointly constitute a second control circuit SC2 which is coupled to the point P via diode D1. Amplifiers I1-I3 are inverting amplifiers.
An input of circuit section I' is connected to point A via capacitor C1. An output of circuit section I' is connected to an input of amplifier I2 and an input of amplifier I1. An output of amplifier I1 is connected to a first input of AND-gate AND. An output of amplifier I2 is connected to an input of monostable multivibrator MMV. An output of monostable multivibrator MMV is connected to a first input of NOR-gate NOR. An output of NOR-gate NOR is connected to the control electrode of the second switching element via amplifier I3. An input of the circuit section II' is connected to the point P via diode D1. An output of circuit section II' is connected to a second input of AND-gate AND. An output of AND-gate AND is connected to a second input of NOR-gate NOR.
The circuit sections shown in FIG. 2 operate as follows.
During a decrease of the voltage at point A, the output of circuit section I' is high. The output of the circuit section I' is low during the remaining period. Since I1 is an inverting amplifier, the first input of AND-gate AND is low in that case. Since the output of circuit section I' is only high during a decrease of the voltage at point A, a pulsatory signal is generated at the output of circuit section I' due to this decrease of the voltage at point A. This pulsatory signal is applied via amplifier I2 to monostable multivibrator MMV which converts this signal into a control pulse having a predetermined period of time because the output of monostable multivibrator MMV is high during the predetermined period of time. This control pulse is applied to the control electrode of the second switching element via NOR-gate NOR and amplifier I3. The third control circuit thus renders the second switching element 6 conducting during a predetermined period of time after the decrease of the voltage at point A.
When the voltage at point P is low, the output of circuit section II' is high. Only when the voltage at point P is low and the voltage at point A no longer decreases, in other words, when the first switching element has been rendered non-conducting, is the output of AND-gate AND and hence also the second input of NOR-gate NOR high. In this situation, the second control circuit renders the second switching element conducting. Amplifier I1 prevents the second control circuit from rendering the second switching element conducting in an undelayed manner, for example, due to unwanted interactions with other circuit sections, during the decrease of the voltage at point A.
In FIG. 3, circuit sections and components corresponding to the circuit sections and components of FIG. 2 are denoted by the same symbols. The configuration shown in FIG. 3 differs from that in FIG. 2 only in that the circuit section II also comprises a comparator COMP. The cathode of diode D1 is not connected to point P but to an output of the comparator COMP, respective inputs of which are connected to the point P and the point A. The diode D1 conveys current only when the voltage at point P is more than a threshold voltage lower than the voltage at point A. Since the voltage at point A in the configuration shown in FIG. 3 is compared with that at point P, the second control circuit has a very reliable operation. The operation of the configuration shown in FIG. 3 is further similar to that of the configuration shown in FIG. 2 and will not be described separately.
FIG. 4 shows an embodiment of the circuit section II'. Vs is a voltage source supplying a substantially constant power supply voltage. A first terminal of Vs is connected to a second terminal thereof by means of a series arrangement of a current source IS, a transistor S1 and a diode D3. The first terminal is also connected to an anode of diode D3 by means of a series arrangement of diode D2, ohmic resistor R1 and zener diode Z1. A common point of ohmic resistor R1 and zener diode Z1 is connected to a control electrode of the transistor S1 and to an anode of diode D1. A common point of current source IS and transistor S1 functions as an output. FIG. 4 also shows the shape of the voltage at point P and the corresponding voltage at the output. If the voltage at point P is relatively high, the transistor S1 is turned on and the voltage at the output is low. If the voltage at point P decreases below a level denoted by a horizontal broken line in FIG. 4, the transistor is turned off so that the output will be high.
FIG. 5 shows an embodiment of the circuit section 1'. Vs is a voltage source supplying a substantially constant power supply voltage. A first terminal of Vs is connected to a second terminal thereof by means of a first series arrangement of a current source IS1 and a transistor S2 and by means of a second series arrangement of a current source IS2 and a transistor S3. Current source IS1 supplies a current which is twice as high as that supplied by the current source IS2. Respective control electrodes of transistors S2 and S3 are interconnected and are connected to a common point of current source IS1 and transistor S2. Consequently, the two transistors constitute a current mirror. Both control electrodes are also connected to point A via capacitor C3. A common point of current source IS2 and transistor S3 constitutes an output. FIG. 5 also shows the shape of the voltage at point A and the associated voltage at the output. If the capacitor C3 does not convey a current because the voltage at point A does not change, the output out of the circuit section shown in FIG. 5 is low. This is caused by the fact that transistor S3 attempts to convey as much current as transistor S2 but receives a current from current source IS2 which is only half as high. If the voltage at point A increases, the current through transistor S2 also increases via capacitor C3. Since transistor S2 constitutes a current mirror together with transistor S3, transistor S3 is also rendered more conducting so that the output out remains low. However, if the voltage at point A decreases, the current in transistor S2 will decrease through capacitor C3. Consequently, transistor S3 also becomes less conducting. If the current conveyed by transistor S3 becomes lower than the current supplied by current source IS2, the voltage at the output out becomes high. As a result, the output of the circuit section shown in FIG. 5 is high only during a decrease of the voltage at point A.
In FIG. 6, circuit sections and components corresponding to the circuit sections and components of FIG. 2 or FIG. 3 are denoted by the same symbols. The configuration shown in FIG. 6 differs from that in FIG. 3 only in that the monostable multivibrator MMV, the NOR-gate NOR and the amplifier I3 are replaced by a circuit section DR coupled to the second control circuit, the third control circuit and the control electrode of the second switching element for rendering the second switching element conducting in a delayed manner via the third control circuit and for rendering the second switching element conducting in an undelayed manner via the second control circuit. A first input of the circuit section DR is connected to the output of AND-gate AND. A second input of the circuit section DR is connected to the output of amplifier I2. An output of circuit section DR is connected to the control electrode of the second switching element. In the part of the circuit arrangement shown in FIG. 6, the second control circuit is constituted by circuit section II', amplifier I1 and AND-gate AND. The third control circuit SC3 is constituted by circuit section I', capacitor C1 and amplifier I2. If the output of the AND-gate AND is high, the circuit section DR renders the second switching element conducting in an undelayed manner. If the output of amplifier I2 is high, the circuit section DR renders the second switching element conducting in a delayed manner. Due to this delayed switching of the second switching element via the third control circuit, the risk that the two switching elements are rendered conducting simultaneously, for example, due to specific lamp behavior, is reduced considerably.
FIG. 7 shows the structure of the circuit section DR which is present in the part of the circuit arrangement according to the invention, shown in FIG. 6. K3 and K4 are terminals between which a power supply voltage is present during operation of the circuit section DR. Terminal K3 is connected to terminal K4 by means of a series arrangement of a current source J0 and capacitor C2. Capacitor C2 is shunted by a series arrangement of transistors MN2 and MN3. A main electrode of transistor MN2 is connected to a control electrode of transistor MN2. Terminals K3 and K4 are also connected by means of a series arrangement of transistor MN4, diode D5 and transistor MN6. Transistor MN4 and diode D5 are shunted by transistor MP7. The output of circuit section DR is constituted by a common point of diode D5 and transistor MN6. A common point of current source J0 and capacitor C2 is connected to a control electrode of transistor MN4. The first input of circuit section DR is constituted by terminal IN1. Terminal IN1 is connected to an input of inverting amplifier INV and to a first input of NOR-gate NORG. An output of inverting amplifier INV is connected to a control electrode of transistor MP7. The second input of circuit section DR is constituted by terminal IN2 and is connected to a second input of NOR-gate NORG. An output of NOR-gate NORG is connected to a control electrode of transistor MN3 and a control electrode of transistor MN6.
The circuit section shown in FIG. 7 operates as follows.
If the two inputs of the circuit section DR are low, the output of NOR-gate NORG is high and the transistors MN3 and MN6 are turned on. In this situation, the control electrode of transistor MN4 is maintained at a threshold voltage by current source J0 and transistor MN2. Diode D5 prevents transistors MN2 and MN4 from forming a current mirror. If one of the two inputs of circuit section DR becomes high, the output of NOR-gate NORG will become low so that the transistors MN3 and MN6 are turned off.
If the second input is rendered high, transistor MP7 remains turned off. The voltage at the control electrode of transistor MN4 starts to increase linearly at a rate which is determined by the capacitance of capacitor C2 and the amplitude of the current supplied by J0. Transistor MN4 now operates as a source follower, and the voltage at the output of circuit section DR will increase at the same rate as the voltage at the control electrode of transistor MN4. The second switching element is rendered conducting in a delayed manner by this voltage which is present at the output of circuit section DR. If the voltage at the second input becomes low again, the output of NOR-gate NORG becomes high so that transistor MN6 is turned on and the output of circuit section DR almost immediately becomes low. Consequently, the second switching element is almost immediately rendered non-conducting.
If the first input of the circuit section DR becomes high, the transistor MP7 is almost immediately turned on so that the output of circuit section DR becomes almost immediately high and the second switching element is rendered conducting in an undelayed manner. If the first input becomes low again, transistor MP7 is almost immediately turned off so that the output of the circuit section DR becomes almost immediately low due to the fact that transistor MN6 is turned on, and the second switching element is almost immediately rendered non-conducting. | In a self-oscillating bridge circuit, the control of the low switch (6) is derived from the control of the high switch (7) by coupling the control circuitry (SC2) of the low switch to a terminal P in the control circuitry of the high switch by means of a diode (D1). The control of the low switch is improved by incorporating control circuitry (SC3) for rendering the low switch conducting for a short period after the high switch has become non-conducting. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for admissions control in a connectionless communications network.
BACKGROUND TO THE INVENTION
[0002] Admissions control is a significant problem in communications networks and especially in connectionless, packet-based, communications networks. For example, consider a particular link in a communications network. If that link becomes congested, the traffic is unable to flow through the link and packets are dropped. This results in deterioration in quality of service for all services provided over that link. In particular situations this has especially severe impact, for example, when the link provides the main access route from a communications network of a particular enterprise or residential customer to a core communications network.
[0003] These problems are particularly relevant for voice over internet protocol (VOIP) solutions. If a link is already carrying the maximum number of VOIP calls, or other non-voice traffic, adding additional calls seriously degrades the voice quality of existing calls using that link. The new call added to the link also has poor voice quality. Continuing to add calls to the link degrades the quality of all calls until none of those calls are recognisable.
[0004] The term “Voice over Internet Protocol call” is used herein to refer calls involving any suitable type of media over internet protocol. For example, speech calls, fax calls, modem calls or video calls.
[0005] [0005]FIG. 4 shows a voice over internet protocol (VOIP) communications network in which admissions control is required. A local area network 40 (LAN), or any suitable type as known in the art, is connected via an access link A to a core communications network 42 . Any suitable type of access link can be used as is known in the art, for example, Gigabit Ethernet, Digital Subscriber, or leased line. However, link A is unable to support calls into the core from all endpoints in the LAN simultaneously. Those endpoints are said to be “concentrated” behind link A. Concentration can be implemented in network designs for example where many of the calls are anticipated to stay on the LAN behind an access link to a core network and/or where not all of the endpoints will need to make calls into the core network at the same time. In this way a customer's LAN may be connected to a core network via a single access link that supports both voice and data at the same time. In such situations there is a need to detect when over utilisation of the access link is likely to occur in order that preventative measures can be taken. However there are currently no suitable methods for detecting link over-utilisation and communicating this to a call server or other management node in order that link over-utilisation can be prevented.
[0006] Another example is illustrated in FIG. 5. In this case an enterprise network 50 is connected via a fixed wireless link 51 to a core network 52 . The fixed wireless link has limited bandwidth and is unable to support calls from all endpoints in the enterprise network at one time. In addition varying amounts of bandwidth are required for calls, depending on the type of call required (e.g. voice calls can use a multitude of different codecs, each of which have their own bandwidth characteristics, fax call, etc.) and this further increases the complexity of the admissions control problem.
[0007] One known form of admissions control for the “access” portion of a network is found in the Packetcable (Trade Mark) standards for dynamic quality of service (DQOS). Packet Cable is a set of protocols developed by Cable Television Laboratories, Inc. The protocols are designed to enable quality of service enhanced communications using packetised data transmission technology to a subscriber's home over the cable network. A network superstructure that overlays the two-way data-ready digital cable television network is used. The Packetcable protocols are thus specifically designed for such cable television networks. Another disadvantage of these protocols from the point of view of admissions control is that all the internet protocol media endpoints (e.g. user terminals and other packet media endpoints) and devices on the edge of low-bandwidth links (i.e. in the Packetcable architecture, the CMTS) are required to fully support the reservation protocol (RSVP). In addition those endpoints and devices are required to support mechanisms to send and receive session identifier information from a call server. Also the call server and the devices at the edge of the low bandwidth link need to support the common open policy service (COPS) protocol. This is problematic because many existing communications networks are formed from equipment made by different manufacturers and where many of the nodes or endpoints do not support RSVP or COPS where needed. In addition, the Packetcable protocols require all layer-3 aware devices in a media path to support RSVP in order that call admission control can be effected. However, this is not the case for many communications networks. For example, FIG. 5 shows a low-bandwidth link 51 where nodes at either end of that link are only layer-2 aware devices. Therefore Packetcable protocol type call admission control mechanisms would not be effective. Other disadvantages of the Packetcable approach to call admission control include that no support for layer 2 flows is provided and the fact that all devices in the network which support RSVP are required to have some policy awareness.
[0008] The reservation protocol is defined in the Internet engineering task forces' request for comments (RFC) 2205 whilst COPS is defined in RFC 2748.
[0009] The known approach to call admissions control mentioned above which uses the Packetcable standards is now described in more detail. This approach involves the Common Open Policy Service (COPS) with RSVP. An example of a typical architecture for COPS and RSVP admissions control is given in FIG. 6 which shows two access networks connected to a core communications network via Policy Enforcement Points (PEPs). The core network comprises a policy decision point (PDP) and a call server. Using this approach, the originating and terminating parties make an admissions request to the call server using H.248, or any other suitable device control protocol such as media gateway control protocol (MGCP) or NCS where NCS is the Packetcable specific version of MGCP as indicated in FIG. 6. The call server then grants an appropriate service ticket to each of those parties. Next, the originating party or originating PEP spawns a network admission request through the network. A similar request is spawned by the destination party or destination PEP to request a call flow in the opposite direction and so provide a 2-way flow. The PDP receives the admission requests and forwards those to the call server.
[0010] The call server verifies the service tickets. The PDP decides whether to accept or refuse the request on the basis of available bandwidth on the low-bandwidth access link and if accepted, opens a reserved path for media for the new call. However, the COPS and RSVP approach is problematic because significant post dial delay occurs as a result of the admission process and also the other problems mentioned above with respect to the Packetcable approach apply. In addition, the means by which the call server and PDP communicate is not yet fully standardized.
[0011] More recently the Internet Engineering Task Force (IETF) have set up a working group to consider ways in which middleboxes can be controlled. The term “middlebox” is used herein to refer to an entity in a communications network which is associated with a low-bandwidth link and which is able to allow or disallow individual traffic flows over that link. For example, the middlebox may be a node connected to one end of a low-bandwidth link. Also, the middlebox may be part of a node which is not directly connected to one end of a low-bandwidth link but which is able to allow or disallow individual traffic flows over that link. The IETF working group is referred to as the MIDCOM (middlebox communications) working group. In the future it may be possible to use protocols developed by the MIDCOM working group to control such middleboxes in order that they themselves perform admissions control. However, these MIDCOM protocols are not yet developed and ratified. Indeed, we understand that the MIDCOM working group is currently working on the control of middleboxes for network address translation and firewall purposes, but not for admissions control purposes. It will be some time before this is the case and those protocols are deployed on all the required nodes in existing communications networks. In addition such MIDCOM methods would require a means by which a call server is automatically able to identify which middleboxes are relevant for a particular call. However, “middlebox discovery” mechanisms like this are not currently known.
[0012] Thus a means of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP approaches is required which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls, lawful intercept (known in North America as CALEA), and other potential call service situations is required.
[0013] The invention seeks to provide an improved method and apparatus for performing admissions control which solves or at least mitigates one or more of the problems mentioned above.
[0014] Further benefits and advantages of the invention will become apparent from a consideration of the following detailed description given with reference to the accompanying drawings, which specify and show preferred embodiments of the invention.
SUMMARY OF THE INVENTION
[0015] A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls and/or lawful intercept Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The information in the database is manually configured for example although this is not essential. The database also has information about which media endpoints are behind what middle box, and maximum bandwidths for the link associated with each middlebox. The call servers are used to keep a running tally of the amount of VoIP call bandwidth associated with each middlebox on the edge of a low-bandwidth link, and to accept or refuse calls on the basis of the bandwidth information on a per-call basis
[0016] According to a first aspect of the present invention there is provided a call server for use in a connectionless, packet, communications network in order to provide admissions control, said communications network comprising a plurality of middleboxes, each middlebox being associated with a different link in the communications network and arranged to control packet flow over that link, said call server comprising:
[0017] an input arranged to receive a call admission request from an originating packet media endpoint, said call admission request comprising information about the originating packet media endpoint, and a destination packet media endpoint;
[0018] an input for accessing information about all first middleboxes associated with the originating node and all second middleboxes associated with the destination node, together with information about the amount of available bandwidth on the link associated with each of those middleboxes;
[0019] a processor for determining whether to accept the call admission request on the basis of the accessed information about available bandwidth;
[0020] an output arranged to output the results of the determination as to whether to accept the call admission request.
[0021] This provides the advantage that the call server effectively provides admission control capability on behalf of the middleboxes. Because the call server is able to access information about middleboxes and the available bandwidth on the low-bandwidth links associated with those middleboxes it is able to perform call admission control. This is achieved without the need to modify existing packet media endpoints such as media gateways and internet protocol endpoints. In addition, it is not necessary for those packet media endpoints to be fully RSVP enabled or for the middleboxes to be MIDCOM enabled with respect to call admissions control. Another advantage is that call admission control over the low-bandwidth links is achieved even where nodes at either or both ends of the low-bandwidth link are layer-2 but not layer-3 aware. This is because effectively the call server performs the admission control determinations.
[0022] The information about the destination packet media endpoint is preferably provided by a destination or called party number representing the packet media endpoint.
[0023] Preferably the processor is arranged to determine whether to accept the call admission request on the basis of the accessed information about available bandwidth together with information about the bandwidth requirements for the call. For example, a pre-specified value of the bandwidth requirements for any call can be used. Alternatively the call server can determine what bandwidth is needed as explained in more detail below.
[0024] Preferably the processor is further arranged to determine whether all the first middleboxes are the same as all the second middleboxes and to accept the call admission request in such cases. This provides the advantage that when the call path does not traverse a low-bandwidth link associated with a middlebox then the call is simply accepted.
[0025] Advantageously said processor is further arranged to identify which of the first middleboxes are not also second middleboxes and vice versa, and wherein said processor is arranged to determine whether to accept the call admission request on the basis of accessed information about available bandwidth only for links associated with those identified middleboxes. This ensures that when the call path or flow does traverse one or more low-bandwidth links associated with middleboxes, then call admission control is performed for each of those links.
[0026] According to another aspect of the present invention there is provided a method of performing admissions control in a connectionless, packet, communications network, said communications network comprising a plurality of middleboxes, each middlebox being associated with a different link in the communications network and arranged to control packet flow over that link, said method comprising the steps of, at a call server:
[0027] receiving a call admission request from an originating packet media endpoint, said call admission request comprising information about the originating packet media endpoint and a destination packet media endpoint;
[0028] accessing information about all first middleboxes associated with the originating packet media endpoint and all second middleboxes associated with the destination packet media endpoint, together with information about the amount of available bandwidth on the link associated with each of those middleboxes;
[0029] determining whether to accept the call admission request on the basis of the accessed information about available bandwidth; and
[0030] outputting the results of the determination as to whether to accept the call admission request.
[0031] The communications network is preferably an internet protocol communications network at layer 3. At layer 2, a variety of protocols could be used, such as ATM, Ethernet, PPP, etc. A variety of layer 1 physical layers can also be provided. The calls are preferably voice over internet protocol calls.
[0032] The middle boxes at both ends of the low-bandwidth link are arranged to use quality of service (QOS) mechanisms as known in the art to prioritise VoIP traffic from other non-VoIP traffic accessing the low-bandwidth link. This is accomplished using well known classification techniques such as packet marking, port based, VLAN based, etc., as well as traffic shaping, and traffic dropping as known in the art. The end-result is that the voice traffic always has priority over non-voice traffic. If there is ever voice traffic to be sent, it is always sent over the low-bandwidth link ahead of non-voice traffic. This results, essentially, in the voice traffic having complete access to all the available bandwidth on the access link. The term “voice traffic” is used here and in the document as a whole to refer to any suitable type of media in a voice over IP call, for example, speech, fax, video and modem.
[0033] Preferably said information about bandwidth requirements for the call comprises session description protocol (SDP) information received from both the originating and destination packet media endpoints. SDP is specified in the IETF's RFC number 2327. This provides a simple and effective means by which bandwidth requirement information can be obtained by the call server on a per-call basis. The call server is also able to adjust the bandwidth requirements used for the call if these requirements change in the SDP information, for example, as codec requirements are negotiated between the packet media endpoints during call setup time, prior to answer. (A codec is a device for converting speech into signals suitable for transfer by a packet based protocol.) Even post-answer, it is possible to use SDP changes to change the codec being used, and the call server is preferably arranged to take this into account when doing admissions control. Suppose that the call server detects a change to a new codec that requires more bandwidth than previously required for a call. In that case, if there is not enough bandwidth on a link used in this call to change to the new codec, then the Call Server is preferably arranged to force the call to remain at the current, un-modified bandwidth.
[0034] In one embodiment said call is a voice call and said information about bandwidth requirements for the call comprises information about one or more codecs to be used in the call. Also, the call may be a conference call to be established using a conferencing service in the communications network. In addition the call may be subject to lawful intercept as explained in more detail below.
[0035] In another embodiment the communications network comprises two or more call servers, and wherein said method further comprises: receiving said call admission request at an origination call server associated with the origination packet media endpoint and determining whether a destination call server, associated with the destination packet media endpoint is the same as the origination call server. This provides the advantage that admissions control for calls which traverse realms of more than one call server can be carried out.
[0036] Advantageously, when said determination indicates that the destination call server and the origination call server are different, the method comprises allowing the origination and destination packet media endpoints to negotiate as to a codec to be used for the call and to send information about that codec to both the origination and destination call servers. This codec can be used to determine an indication of bandwidth requirements for the call based on the codec information. Preferably, the negotiation about which codec to use is accomplished using known methods such as via session initiation protocol (SIP) or SIP-T. These protocols are able to carry SDP information regarding the call between the origination and destination call servers as described below.
[0037] Preferably, for all middleboxes associated with the origination packet media endpoint, the origination call server accesses information about available bandwidth and for all middleboxes associated with the destination packet media endpoint, the destination call server accesses information about available bandwidth.
[0038] Furthermore, if the call request is refused, instructions are sent to the origination packet media endpoint to provide a refusal indication to a calling party terminal which initiated the call request.
[0039] Also, if the call request is accepted, a database of middlebox information is updated with information about the call and updated again when that call ends.
[0040] Advantageously, one or more of said middleboxes are arranged to perform call admission control themselves under MIDCOM protocol control. This means that the method of the present invention can be implemented in communications networks which contain a mixture of MIDCOM enabled and non-MIDCOM enabled equipment. However the present invention does not seek to provide a MIDCOM protocol based solution although some embodiments of the present invention are operable in networks which contain a mixture of MIDCOM enabled and non-MIDCOM enabled equipment.
[0041] The invention also encompasses a communications network comprising at least one call server as specified above. Preferably, every originating and every destination packet media endpoint connected to a particular middlebox is controlled by the same call server. By specifying requirements for network topology in this way it is possible to use a simplified method of call admissions control as described herein.
[0042] The invention also encompasses a computer program arranged to control a call server such that the method specified above is carried out. Any suitable programming language may be used for the computer program as is known in the art.
[0043] The preferred features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] In order to show how the invention may be carried into effect, embodiments of the invention are now described below by way of example only and with reference to the accompanying figures in which:
[0045] [0045]FIG. 1 is a flow diagram of a call admission control method according to an embodiment of the present invention;
[0046] [0046]FIG. 2 is a flow diagram of another call admission control method according to another embodiment of the present invention;
[0047] [0047]FIG. 3 is a schematic diagram of a communications network comprising a call admission control system;
[0048] [0048]FIG. 4 is a schematic diagram of a prior art voice over internet protocol (VoIP) communications network;
[0049] [0049]FIG. 5 is a schematic diagram of a prior art voice over internet protocol (VoIP) communications network;
[0050] [0050]FIG. 6 is a schematic diagram of a typical COPS and RSVP admissions control architecture according to the prior art;
[0051] [0051]FIG. 7 is a schematic diagram of another communications network comprising a call admission control system;
[0052] [0052]FIG. 8 is a schematic diagram of a communications network comprising a conference bridge and a call admission control system according to an embodiment of the present invention.
[0053] [0053]FIG. 9 is a schematic diagram of a communications network comprising a call admissions control system and a lawful intercept system.
DETAILED DESCRIPTION OF INVENTION
[0054] Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved.
[0055] The term “low bandwidth link” is used to refer to a connection between two nodes in a communications network, where the capacity of the link is less than the capacity required should all entities connected to one end of the link issue communications over that link simultaneously. Typically there is only one such low bandwidth link between the two nodes referred to immediately above although this is not always the case.
[0056] The term “packet media endpoint” is used to refer to a terminal that is suitable for connection (possibly indirectly) to a middlebox or to refer to a node via which terminals access a middlebox (e.g. a media gateway).
[0057] The term “call agent” is used to refer to a node which is able to control a middlebox via the MIDCOM protocol. For example, a call server or a media gateway controller may be a call agent if these entities are MIDCOM enabled. In the present invention it is not essential for the call server to be MIDCOM enabled and in a preferred embodiment it is not MIDCOM enabled.
[0058] The present invention addresses the problem of admissions control by using a call server which has access to a pre-configured database of information about middleboxes and the available bandwidths at the low-bandwidth links associated with those middleboxes. By using pre-configured information in this way, a simple and effective means of call admission control is obtained and there is no need to make changes to existing IP media endpoints or to have MIDCOM enabled middleboxes. In addition, by specifying particular requirements for network design and topology it is possible to deal with situations in which more than one call server is involved. It is also possible to deal with complex service interactions such as conference calls and lawful intercept. In addition, the solution works for low bandwidth links where the edges of the low bandwidth link (i.e. the middle boxes) are capable of looking at either the layer 2 or layer 3 of the flow.
[0059] This is now explained in more detail with reference to FIGS. 1, 2 and 3 . FIG. 3 gives a schematic diagram of a communications network comprising a call admission control system according to the invention and FIGS. 1 and 2 are flow diagrams of methods of call admission control in the network of FIG. 3.
[0060] [0060]FIG. 3 shows a Voice over IP communications network 30 comprising a plurality of nodes interconnected by links and for clarity only some of the nodes and links are shown. The communications network 30 comprises one or more call servers and in this example two call servers 31 , 32 are shown and these are interconnected by link 38 , which may be indirect and which uses a suitable protocol such as SIP-T for inter-call-server communication. Each call server 31 , 32 is associated with one or more middleboxes 35 ; that is, the call server is able to control packet media endpoints that are behind those middleboxes with which the call server is associated. As explained above each middlebox is connected (possibly indirectly) to one or more packet media endpoints 36 and those packet media endpoints are connected to one or more terminals via which users are able to access the communications network. It is also possible for a single packet media endpoint to be connected behind more than one middlebox and thus more than one low bandwidth link although this is not shown in FIG. 3 for reasons of clarity.
[0061] Considering an individual call server, this is used to provide services to terminals connected to packet media endpoints. For example, in FIG. 3, call server 31 can be thought of as serving realm A and being associated with the middleboxes, packet media endpoints and terminals in its realm. Similarly call server 32 serves realm B. The two call servers 31 , 32 are connected to one another either directly or indirectly. Communication between call servers 31 , 32 is accomplished through the use of a well known inter-call-server communication protocol such as SIP-T as known in the art.
[0062] Accessible by each call server is a database or other information store 33 , 34 . These contain pre-specified information about all the middleboxes in the particular call server's realm. This information comprises:
[0063] For each middlebox in the realm, which packet media endpoints are associated with that middlebox, as well as, for each packet media endpoint, what the associated middlebox is;
[0064] For each middlebox in the realm the maximum possible bandwidth of the low-bandwidth link associated with that middlebox;
[0065] For each middlebox in the realm the current available bandwidth on the associated low-bandwidth link;
[0066] Optionally, information about whether each middlebox supports MIDCOM based protocol admissions control.
[0067] With reference to FIG. 1, when a call request is made by a user of a terminal, a call request message is sent from that terminal to the associated call server via an packet media endpoint and one or more middleboxes. The call request message is preferably in the form of a device control call origination message using a protocol such as H.248, media gateway control protocol or any other suitable protocol as known in the art.
[0068] The call request takes place in multiple stages although this is represented in FIG. 1 as one stage for clarity. The stages of the call request are known in the art and the exact details depend on the particular device control protocol used. An outline of the type of steps involved is:
[0069] Offhook from packet media endpoint to call server.
[0070] Call server tells packet media endpoint to create connection and collect digits.
[0071] Packet media endpoint tells call server the preferred bandwidth requirements for the call as well as IP addressing details, etc. (i.e. SDP information).
[0072] Packet media endpoint sends digit information to the call server and the call server uses this to form the destination packet media endpoint identity.
[0073] For example, consider a call request from terminal C in FIG. 1. The request message would proceed to packet media endpoint F, through middlebox 1 and to origination call server 31 . The call request message contains information about the call destination as well as the origination and destination packet media endpoints (as mentioned above) and also information about the bandwidth requirements for the call (see box 10 of FIG. 1).
[0074] The origination call server 31 next checks whether the origination and destination packet media endpoints are both in its realm (see box 11 of FIG. 1). For example, if the destination party is terminal D in FIG. 3 then this is the case; the origination packet media endpoint F and the destination node E are both in realm A. In such cases the method proceeds as in FIG. 1; otherwise the method of FIG. 2 is adopted.
[0075] Considering the case where the method of FIG. 1 applies, the call server next checks whether call admission control is required. For example, if the origination and destination terminals are both served by the same packet media endpoint, then the call does not need to flow over a low bandwidth link and so no call admission control is needed. In order to check this, the call server 31 accesses its middlebox database 34 . Details of all first middleboxes associated with the origination packet media endpoint are found. For example, these could be middlebox 1 in FIG. 3. Then details of all second middleboxes associated with the destination packet media endpoint are found. These could be middlebox 2 in FIG. 3. The call server 31 then checks these two sets of middleboxes for any items which are only in one of the sets. If all of the first middleboxes are the same as the second middleboxes then no call admission is required (see boxes 12 and 13 of FIG. 1) and the call request is accepted. Otherwise, any first middleboxes which are not also second middleboxes and vice versa are identified. For each of these middleboxes information about currently available bandwidth is obtained (see box 14 of FIG. 1).
[0076] If the bandwidth required for the call is less than each of the available bandwidths for those middleboxes then the call is accepted (see boxes 15 and 16 of FIG. 1). Otherwise the call is refused (see box 17 of FIG. 1). For example, consider a call from terminal C to terminal D. The low bandwidth links associated with both middleboxes 1 and 2 have to have enough available capacity for the proposed call. (The call server may not have empirical information about the available bandwidths but instead may use a counter or token system representing units of bandwidth or any other suitable scheme for indicating the relative amount of bandwidth).
[0077] When a call is accepted, the appropriate middlebox database is updated once the call begins and when the call ends. When a call is refused it is possible for the end user to be informed, for example by sending an instruction from the call server 31 to the destination packet media endpoint to play a special tone or a recorded announcement.
[0078] When call admission is barred then it is unlikely that a centralised announcement resource can be used to play an announcement, because of congestion in the network for example. Also, in order to use a centralised announcement resource the call admission control process would need to be carried out again. In view of this a treatment tone is preferably used or an announcement resource at the packet media endpoint itself.
[0079] As described with reference to FIG. 1, the call server receives information about the bandwidth requirements for the proposed call. This is preferably achieved via SDP information from the packet media endpoints (as mentioned above). In a preferred embodiment involving VoIP calls, the call server obtains the bandwidth requirement information by examining session description protocol (SDP) messages from each of the packet media endpoints in its realm. These message enable the call server to determine which codecs will be used in the call, as is known in the art. Then, based on the codec to be used in the call, the call server is able to allocate one or more bandwidth credits to the call. A codec using more bandwidth requires more credits. Thus in this embodiment, the call server also has access to pre-specified information about all possible codecs that may be used in calls in its realm and the amount of bandwidth needed by those codecs.
[0080] The method of FIG. 1 thus does not require the middleboxes to have MIDCOM capability and the packet media endpoints may be of any suitable type whether RSVP enabled or not. The method is therefore operable for networks formed from mixed equipment with some entities being MIDCOM controllable and some not if required.
[0081] In the case that the destination packet media endpoint is in a different realm from the origination packet media endpoint the method of FIG. 2 is used. The origination call server 31 receives a call request from packet media endpoint E for example, where the destination packet media endpoint is G for example. The call server recognises that packet media endpoint G is not in its realm, but instead in the realm of destination call server 32 . This is achieved without reference to the middlebox database. Rather, standard call server translation and routing methods are used as is known in the art to determine that access node G is in the realm of destination call server 32 . The origination and destination packet media endpoints are then allowed to negotiate as to which codec will be used for the call (in the case of a VoIP call) as is known in the art. (As explained above, a codec is a device for converting speech into signals suitable for transfer by a packet-based protocol and one or more codecs are associated with each call server.) Information about which codec is to be used is then sent to each of the origination and destination call servers 31 , 32 (see box 22 of FIG. 2). This is preferably achieved using standard inter-call-server signalling such as SIP-T as known in the art.
[0082] Using the codec information, or other information about bandwidth requirements for the call both call servers 31 , 32 allocate bandwidth credits for the call (see box 23 of FIG. 2). That is, each call server determines an indicator of how much bandwidth is needed for the call. Each call server then accesses its middlebox database to check whether the available bandwidth is enough for the call. This is done in a similar way described with respect to FIG. 1. That is, each call server determines which of its middleboxes are involved in the call and checks the available bandwidth on each of the associated low-bandwidth links.
[0083] As a result, if any of the call servers decides to refuse the call, the call is refused (see box 24 of FIG. 2). Otherwise, the call is accepted (see box 25 of FIG. 2). If the call is refused a treatment tone or an announcement is made as described above with reference to FIG. 1.
[0084] Thus the method of FIG. 1 involved checking for situations where no call admission control is needed. However, the method of FIG. 2 does not require such a check because the origination and destination packet media endpoints are always different when the call servers are different provided a particular network design is followed. That is, the network design should not have any middleboxes which are members of more than one realm. Such a situation is illustrated in FIG. 7 which is the same as FIG. 3 except that middlebox 3 is in both realms A and B.
[0085] In a preferred embodiment, the call server determines whether call admission control is required by using information from the middlebox database. For example, if the middlebox database shows that the access node concerned is behind a middlebox and also if the middlebox database shows that the call server is required to perform call admissions control on behalf of that middlebox.
[0086] However it is not essential for the call server to make this determination as described above. Another option is to add an identifier to call request messages as now described.
[0087] In order to inform the call server(s) that call admission control is required an identifier may be added to the call request message. This indicates the need for the call server to count the admissions through each middlebox on behalf of those middleboxes. However, in the case that some of the middleboxes are MIDCOM enabled and able to carry out their own call admission control, such an indicator is useful. For example, if the call server knows that a particular middlebox is MIDCOM enabled in that way, it can simply request call admission control from that middlebox.
[0088] In a preferred embodiment the call server uses a tag (called CAC-CSCount for example) to note in the middlebox database each middlebox that cannot perform call admission control via MIDCOM. Using the methods of FIGS. 1 and 2 the call server then effectively keeps track (using a counter mechanism) of the amount of bandwidth passing the low bandwidth link connected to the middle boxes as described above. Pre-specified in the middlebox database is information about the maximum amount of bandwidth allowed through the low bandwidth link connected to each middlebox. This information is obtained in any suitable manner, for example by theoretical calculations or by empirical measurement. If the current value of the bandwidth counter would exceed the maximum amount of bandwidth specified then the proposed call is refused.
[0089] The method is also able to deal with situations involving conference calls where a centralised conferencing service is used. For example, consider the situation in FIG. 8 which shows an access network 80 connected to a core network 81 comprising a conference bridge 83 via a low bandwidth link 82 . If terminal A sets up a call to terminal C then a call path 84 is established and no admissions control is needed. However, if A proceeds to conference B into the existing call then three 2-way speech paths need to undergo admissions control, one path between each of A, B and C and the conference bridge 83 . This is possible using the method of FIG. 1 for each of those paths.
[0090] The method is also able to deal with situations involving lawful intercept whereby calls from a particular entity are intercepted for security or other lawful purposes. This is illustrated schematically in FIG. 9 which is similar to FIG. 8. Consider user A in FIG. 9 and suppose user A to be a lawful intercept target.
[0091] In order for lawful intercept to proceed a centralised resource (referred to as a centralised receptor) is used in the core network. This means that all A's calls must pass the low bandwidth link, even if those calls would not otherwise need to do so (for example, calls to user B in FIG. 9). As a result user A's calls to user B could be dropped as a result of call admissions procedures associated with the low bandwidth link. This could alert user A to the fact that lawful intercept is being used. In order to prevent this, the present invention drops another existing call to provide enough bandwidth for A's call should this be required. In that way, A's call is not dropped and A does not have reason to become suspicious. A key requirement for lawful intercept is that lawful intercept targets are not aware that calls involving them are being monitored.
[0092] In FIG. 3 the middlebox databases 33 , 34 are shown as separate from the call servers 31 , 32 . However, this is not essential. The middlebox database may be integral with its associated call server, or it may be a separate entitiy. This is an implementation decision.
[0093] Any range or device value given herein may be extended or altered without losing the effect sought, as will be apparent to the skilled person for an understanding of the teachings herein. | A method of providing call admission control which does not require using MIDCOM protocol methods, Packetcable protocols or COPS-RSVP approaches is described which is simple to implement, cost-effective and which is able to deal with particular situations such as conference calls. Each link in a communications network over which it is required to perform call admissions control is provided with a middlebox connected at each end of that link such that admissions control can be carried out at one end of the link. Call services are provided by Call Servers, each of which has access to a database containing pre-specified information about all middleboxes in that call server's realm. The database also has information about maximum bandwidths for the link associated with each middlebox. The call servers are used to keep a running tally of the amount of VolP call bandwidth associated with each middlebox on the edge of a low-bandwidth link, and to accept or refuse calls on the basis of the bandwidth information on a per-call basis. | 7 |
BACKGROUND
This invention relates generally to mortise locks, and more particularly to latch assemblies and locking mechanisms for use in reversible mortise locks.
A mortise lock is designed to fit into a mortised recess formed in the edge of a door which is opposite to the edge of the door that is hinged to the door frame. The mortise lock generally includes a rectangular housing, or case, which encloses the lock components. The principal lock component is a beveled latch bolt which projects beyond the edge of the door and into an opening in the door frame to latch the door in a closed position. The latch bolt is moveable to a retracted position inside the case to permit opening of the door by operation of a latch operator, such as a door knob or lever handle.
Mortise locks are typically configured so that the latch operators mounted on the inside and outside surfaces of the door can operate independently. The outside latch operator can either be rotated to retract the latch bolt, or locked against rotation to prevent retraction of the latch bolt. Preferably, the inside latch operator can always be rotated to retract the latch bolt. The locking of the outside latch operator is usually controlled by a manual actuator, such as, for example, push buttons or a pivoted toggle, which is exposed at the edge of the mortise lock near the latch. The manual actuator has an associated link within the mortise lock case which, in one position of the manual actuator, engages a moveable portion of the outside latch operator inside the lock case so as to prevent rotation of the latch operator. In a second position, the link disengages from the moveable portion thus permitting rotation of the outside latch operator. The inside latch operator is usually unaffected by the manipulation of the manual actuator and remains rotatable at all times.
Adjustments must be made to the mortise lock depending on whether the lock is mounted in a left-hand or right-hand door. A mortise lock mounted in a left-hand door must be rotated 180° about a vertical axis for mounting in a right-hand door. Consequently, the latch bolt must also be rotated 180° about a horizontal axis so that the beveled face of the latch faces the door-closing direction. In addition, the inside and outside latch operators of the left-hand door mounted lock become the outside and inside latch operators, respectively, of the right-hand door mounted lock. Therefore, a change must be made if the latch operator controlled by the locking mechanism happens to be the inside latch operator when the lock is installed.
The necessary adjustments to the mortise lock can be accomplished without opening the case. Typically, the latch bolt can be pulled partially out of the housing, usually against the force of a spring, rotated 180° and then allowed to be pulled back into the housing by the spring. However, this arrangement can lead to tampering after the lock is installed since the latch bolt can be reversed even when the mortise lock is in the door, which would prevent the door from closing. Moreover, the conventional mechanisms for reversing the operation of the locking mechanism are complicated and difficult to manipulate.
For the foregoing reasons, there is a need for a latch assembly for use in a reversible mortise lock which includes a latch bolt that cannot be reversed after the lock is installed in a door. Reversal of the latch bolt for use with a door of the opposite hand should be easily accomplished in the field. Further, any corresponding changes in the locking mechanism to effect locking of the outside latch operator should also be uncomplicated. The new latch assembly and locking mechanism should be straightforward in manufacture and use.
SUMMARY
Therefore, it is an object of the present invention to provide a reversible mortise lock wherein the latch assembly cannot be reversed when the lock is installed on the door.
A further object of the present invention is to provide a new latch assembly and locking mechanism for a mortise lock which are simple to reverse in the field prior to installation in the door.
According to the present invention, a mortise lock includes a latch assembly comprising a latch bolt having a first portion adapted to project from an opening in the lock housing in an extended position of the latch bolt while a second portion of the latch bolt remains within the lock housing. The latch bolt is removable from the lock housing through the opening. A securing member inside the housing is releasably attached to the second portion of the latch bolt.
The securing member comprises a securing element having a blocking surface and means for biasing the securing element and blocking surface into engagement with the second portion of the latch bolt for releasably securing the latch bolt to the moving member. The securing element further comprises a disengaging surface which when moved against the force of the biasing means releases the second portion of the latch bolt from the securing member so that the latch bolt may be removed from the lock housing.
In further accord with the present invention, a mortise lock of the type having a latch bolt normally projecting from the lock housing and means including a moveable member in the lock housing connected to a door knob or lever handle for moving the latch bolt to a retracted position in the housing, has a locking mechanism comprising a blocking element in the housing and means for moving the blocking element between a locked position and an unlocked position relative the moveable member. The blocking element has an opening adapted to receive a portion of the moveable member when the blocking element is in the locked position for allowing the moveable member to move and the door knob or lever handle to rotate. A stop is removably positioned in the opening of the blocking element for preventing movement of the moveable member when the blocking element is in the locked position.
Also in accord with the present invention, a mortise lock comprises a housing and a latch bolt removably mounted in the housing through an opening in the housing. A securing member is disposed inside the housing for movement relative to the housing. The securing member comprises a securing element having a blocking surface and means for biasing the blocking surface into engagement with the latch bolt for releasably securing the latch bolt to the securing member. The securing element further comprises a surface which when pressed moves the securing element against the force of the biasing means for releasing the latch bolt from the securing member so that the latch bolt may be removed from the housing. The securing member is moveable between a first position where the latch bolt is inside the housing and a second position where a portion of the latch bolt projects through the opening in the housing. Means for moving the securing member to the first position are provided, including a moveable member in the housing. A blocking element is disposed in the housing and means are provided for moving the blocking element between a locked position and an unlocked position relative to the moveable member. A stop is removably attached to the blocking element and adapted in the locked position to prevent operation of the moveable member.
An important feature of the present invention is that the releasing surface of the securing member is only accessible through the side walls of the mortise lock case. Therefore, latch bolt reversal must be performed before the lock is installed. Moreover, once the latch bolt is freed from the moveable member, the latch bolt can be completely removed from the lock housing, reversed and reinstalled. The blocking element and removable stop for locking the lock are also accessible through the side walls of the lock housing. Thus, repositioning of the stop in the blocking element is also accomplished before installation. Preferably, the stop is a threaded plug which is received in a threaded opening in the blocking element.
Reversal of the latch bolt and locking mechanism is simple to perform prior to installation of the lock. A screw driver is the only tool needed to release the latch bolt from the lock housing for reversal of the latch bolt and locking mechanism. Once the lock is installed in a door, the latch bolt cannot be reversed because the latch bolt cannot be removed from the lock.
Additional objects, features and advantages of the present invention will be apparent from the following description in which references are made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below.
FIG. 1 is a perspective view of an embodiment of a mortise lock assembly according to the present invention;
FIG. 2 is a elevation view of the mortise lock assembly taken along line 2 — 2 of FIG.
FIG. 3 is a perspective exploded view of an embodiment of a latch assembly used in the mortise lock assembly FIG. 1;
FIGS. 4 and 5 are opposite side elevational views of an anti-friction latch used in the latch assembly of
FIGS. 6 and 7 are front and rear elevational views, respectively, of the latch tail and spring clip of FIG 3 ;
FIGS. 8, 9 , 10 and 11 are side elevational views of the tail plate of FIG. 3;
FIG. 12 is an exploded perspective view of an alternative embodiment of a tail plate and spring clip f use in the latch assembly of FIG. 3;
FIGS. 13 and 14 are front and rear elevational views, respectively, of the tail plate and spring clip embodiment of FIG. 12 similar to FIGS. 6 and 7;
FIG. 15 is a side elevational view of the tail plate embodiment of FIG. 12 similar to FIG. 8;
FIGS. 16 and 17 are side sectional views of the tail plate and spring clip embodiment of FIG. 12 showing the latch tail entering the tail plate taken along line 16 — 16 of FIG. 13;
FIG. 18 . is a side sectional view of the tail plate and spring clip embodiment of FIGS. 16 and 17 in combination with a screw driver blade illustrating the removal of the latch tail from the tail plate;
FIG. 19 is a perspective view of a hub used in the mortise lock assembly of FIG. 1;
FIG. 20 is a sectional view of the mortise lock assembly of FIG. 2 taken along line 20 — 20 of FIG. 2 showing an embodiment of a locking mechanism used in the mortise lock assembly of FIG. 1 in an unlocked position;
FIG. 21 is side elevational view of the locking mechanism embodiment of FIG. 20 with other lock components removed;
FIGS. 22 and 23 are the same views as FIGS. 20 and 21, respectively, but showing the locking mechanism embodiment in a locked position; and
FIG. 24, the same view of the mortise lock assembly of FIG. 2 but showing the latch bolt and deadbolt retracted into the case by actuation of a latch operator.
DESCRIPTION
The latch bolt and locking mechanism according to the present invention are for use in a mortise lock and may be used with any conventional mortise lock assembly such as, for example, the mortise lock assembly described by U.S. Pat. No. 4,118,056, the contents of which are hereby incorporated by reference. Accordingly, detailed explanations of the functioning of all of the mortise lock components are deemed unnecessary for understanding of the present invention by one of ordinary skill in the art.
Referring now to FIG. 1, a mortise lock assembly according to the present invention is shown and is generally designated by reference numeral 30 . The lock 30 comprises a generally rectangular box, or case 32 , for housing the lock components and is adapted to be received in a mortise in the free, or unhinged, edge of a door. One of the side walls of the case 32 comprises a cap 34 which is secured to and forms a closure for the case 32 .
FIG. 2 shows the lock with the cap side wall 34 removed. The case 32 includes a side wall 36 and, as seen in FIG. 2, integral top 38 , bottom 40 , front 42 and rear 44 walls. The front wall 42 has openings for a latch bolt 46 , a deadbolt 48 , an auxiliary bolt 50 and a flush-mounted toggle 52 . A face plate 54 is secured to the front wall of the case 32 and has openings which correspond to the openings in the front wall 42 . The latch bolt 46 , deadbolt 48 and auxiliary bolt 50 are shown projecting from their respective openings in the front wall 42 and face plate 54 .
An embodiment of the latch assembly for use in the mortise lock assembly of FIG. 2 is shown in FIG. 3 and designated generally at 56 . The latch assembly 56 comprises the latch bolt 46 including a bolt head 58 and an integral latch tail 60 , an anti-friction latch 62 , a coil spring 64 , a spring flange 66 , a tail plate 68 and spring clip 70 . The bolt head 58 includes a beveled face 72 and a slot 74 . A short pin 76 extends from one side of the bolt head 58 and into the slot 74 for pivotally mounting the anti-friction latch 62 .
The anti-friction latch 62 is shown in more detail in FIGS. 4 and 5. As seen in FIG. 5, one side of the anti-friction latch 62 has a groove 78 for receiving the pin 76 when the anti-friction latch 62 is slipped into the slot 74 during manufacture. The groove 78 is closed near its open end in a press operation to keep the anti-friction latch 62 in the bolt head 58 . A lever 77 extends from one side of the anti-friction latch and a stub 79 extends from the opposite side. When the latch assembly 56 is in the case (FIG. 2 ), the anti-friction latch 62 and the opening for the latch bolt 46 in the front wall 42 of the case 32 are configured so that the lever 77 engages behind the front wall 42 while the stub 79 engages behind the face plate 54 .
Returning to FIG. 3, the latch tail 60 extends from the rear of the bolt head 58 . The portion 61 of the latch tail 60 adjacent the bolt head 58 is thicker than the free end so that the coil spring 64 must be forced onto that portion of the latch tail thereby holding the coil spring 64 on the latch tail 60 . The free end of the latch tail 60 is rounded and includes a notch 80 longitudinally spaced from the free end. The tail plate 68 is generally cube-shaped and has a pass-through opening 82 for receiving the free end of the latch tail 60 . The spring clip 70 is a flat rectangular piece defining an irregular opening 84 and having an angled tab 86 extending from one edge of the clip 84 . The tail plate 68 has a slot 88 which intersects the tail plate opening 82 for receiving the spring clip 70 . The spring clip tab 86 fits in a groove 90 in the side of the tail plate 68 .
Each side of the tail plate 68 is shown in FIGS. 6 through 11. The tail plate 68 has a support boss 91 which sits against the case side wall 34 when the tail plate 68 is in the case 32 . The support boss 91 has a retraction surface 92 . An opposed boss 94 fits in a linear guide slot 96 in the cap side wall 14 (FIG. 1) for guiding and supporting linear movement of the tail plate 68 . Referring particularly to FIGS. 6 and 7, the tail plate 68 is shown from the front and rear, respectively, with the spring clip 70 in the slot 88 in the tail plate 68 . The irregular opening 84 in the spring clip 70 aligns with the opening 82 in the tail plate 68 . The dimensions of the spring clip 70 and the position of the slot 88 are such that the spring clip 70 partially blocks the opening 82 through the tail plate 68 . The tab 86 is braced against the surface of the groove 90 in the tail plate 68 to bias the spring clip 70 upward to this position as seen in FIGS. 6 and 7.
An alternative embodiment of the tail plate 68 a and spring clip 70 a for use in the latch assembly 56 of the present invention is shown in FIGS. 12 through 15. In this embodiment, the spring clip 70 a is L-shaped and has an irregular opening 84 a . Two coil springs 98 are disposed in depressions 100 (FIG. 15) in the tail plate surface on either side of the groove 90 a for biasing the spring clip 70 a upward to the position shown in FIGS. 13 and 14 partially blocking the opening 82 a in the tail plate 68 a . The other sides of the tail plate 68 a are configured the same as seen in FIGS. 9-11.
Connection of the latch bolt 46 to the tail plate 68 a and spring clip 70 a is shown in FIGS. 16 and 17. In FIG. 16, the free end of the latch tail 60 is shown entering the opening 82 a in the tail plate 68 a . As the latch tail 60 initially enters the tail plate 68 a , the rounded end engages the edge of the opening 84 a in the spring clip 70 a forcing the clip down and compressing the springs 98 . When the latch tail notch 80 passes the spring clip 70 a , the springs 98 push the clip upward so that the edge of the opening 84 a in the clip engages behind the notch 80 in the latch tail 60 securing the latch tail in the tail plate 68 a . It is understood that the embodiments of the tail plate and spring clip in FIGS. 6 through 15 are exemplary and other structures are possible, as long as the function of the overall structure for releasably holding the latch tail in the tail plate is maintained.
As seen in FIG. 2, when the latch assembly 56 is in position in the mortise lock assembly 30 , a substantial portion of the latch bolt 46 is inside the case 32 even when the latch bolt 46 is in the extended position with a predetermined portion projecting beyond the front of the case 32 . The latch tail 60 extends rearwardly from the bolt head 58 through a guide slot formed in a boss 102 fixedly mounted between the side walls 34 , 36 for guiding and supporting the linear reciprocal movement of the latch bolt 46 . The coil spring 64 is held in compression between the bolt head 58 and the spring flange 66 , which is urged against the boss 102 , for normally biasing the latch bolt 46 outwardly to the extended position. A boss 103 on the spring flange 66 fits in a hole 104 (FIG. 1) in the cap side wall 34 for holding the flange 66 in position.
The latch bolt 46 is moveable in the openings in the front wall 42 of the case 32 and face plate 54 to the retracted position inside the case by operation of a latch operator comprising either an inside or outside knob or lever handle (not shown). In addition, the latch bolt 46 automatically retracts when the anti-friction latch 62 and the beveled face 70 of the bolt head 58 engage the door frame upon closing of the door. Initially, the anti-friction latch 62 engages the door frame pivoting the anti-friction latch on the pin 76 in the bolt head 58 . As the anti-friction latch 62 pivots, the lever 77 works against the front wall 42 of the case 32 driving the latch bolt 46 rearward into the case 32 . When the latch operator is released, or the door is in the door 20 B frame, the coil spring 64 returns the latch bolt 46 to the extended position.
According to the present invention, the latch bolt 46 is reversible for use with a door of the opposite hand. In order to reverse the latch bolt 46 , it is necessary to disconnect the latch bolt from the tail plate 68 and remove the latch bolt 46 from the lock assembly 10 . This is accomplished by first removing the face plate 54 and then manually pushing the latch bolt 46 into the case 32 . Next, the user manually depresses the spring clip 70 , which is accessible through the guide slot 96 in the cap side wall 34 . As seen in FIG. 18, by pressing on the spring clip 70 a with a screw driver 106 or other tool, the spring clip 70 a is pushed down against the force of the springs 98 thereby releasing the latch tail 60 from the spring clip 70 a and tail plate 68 a . When the latch bolt 46 is free of the tail plate 68 a , the latch bolt 46 may be pulled through the opening in the front wall 42 of the case 32 (FIG. 1 ), rotated 180° , inserted into the case 32 and reattached to the tail plate 68 a , as described above. The slot 96 and hole 104 in the cap side wall 34 are used for viewing to guide the latch tail 60 through the flange 66 and boss 102 and into the opening 82 a in the tail plate 68 a . Because the anti-friction latch 62 can pivot and move linearly with respect to the bolt head 58 on the pin 76 , at least to the extent of the groove 78 which has not been pressed in, the latch bolt 42 is easily manipulated during removal and reinsertion.
It is understood that other means for biasing the spring clip to the position where the spring clip partially blocks the tail plate opening are possible. For example, the spring clip embodiment shown in FIGS. 12 through 15 would work without the coil springs if the clip material was flexible enough to allow the clip to be pushed down to clear the tail plate opening. Thus, we do not intend ourselves to limit to the specific embodiments of the spring clip biasing means shown herein.
As noted above, the latch operator comprises means for retracting the latch bolt 46 including an inside or outside knob or lever handle. The retracting means comprises two independent, coaxial rollback hubs 108 which are mirror images of one another. The hubs 108 are rotatably mounted in opposed holes in the walls 34 , 36 of the case 32 below the latch assembly 56 (FIG. 2 ). The hub 108 which fits in the case side wall 36 is shown in FIG. 19 . The hubs include a star-shaped aperture 110 for non-rotatable connection to inside and outside spindle drives (not shown) connected to the knobs or lever handles for rotating the hubs 108 . Each hub 108 has an upper rollback surface 112 which faces the rear wall 44 of the case 32 , a forwardly extending boss 114 and downwardly depending legs 116 . As seen in FIG. 2, the legs 116 engage an L-shaped bracket 118 attached to the bottom of the case 32 for preventing clockwise rotation (as seen in FIG. 2) of the hubs 108 . Two torsion springs 120 are mounted on a transverse pin 122 adjacent to the front of each hub 108 . An end of each spring 120 fits in a notch 124 (FIG. 18) in the hubs 108 for restoring the hubs to the neutral or home position when the knob or handle is released. It is understood that, as an alternative, the mortise lock assembly may have a single hub to which both the inside and outside spindle drives are connected.
The retracting means also includes a retractor shoe 126 and a hub lever 128 . The shoe 126 is mounted for linear movement within the case 32 and has a forwardly facing bearing surface 130 for engaging the rollback surfaces 112 of the hubs 108 and a rearwardly facing bearing surface 132 . In this arrangement, the shoe 126 moves linearly rearward in response to counterclockwise rotation, as seen in FIGS. 2 and 24, of either of the rollback hubs 108 . A torsion spring 134 acts between the rear wall 44 and the retractor shoe 126 to urge the shoe toward engagement with the roll back hubs 108 .
The hub lever 128 comprises a generally flat, L-shaped lever disposed within the case 32 against the case side wall 36 . The hub lever 128 is pivotally supported on a pin 129 at its lower forward leg 136 below and in front of the hubs 108 . The upper leg 138 of the hub lever 128 extends upwardly to the rear of the hubs 108 and has a first laterally projecting tab 139 adjacent the rearward bearing surface 132 of the shoe 126 . A portion of the upper leg of 138 of the hub lever 128 is adjacent to the retraction surface 92 of the tail plate 68 . A torsion spring 143 acts between the rear wall 44 and the first tab 139 to bias the hub lever 128 into operative engagement with the retractor shoe 126 .
As seen in FIG. 24, the latch bolt 46 is retracted by rotating one of the rollback hubs 108 . Rotation of the rollback hub 108 causes the rollback surface 112 to engage the bearing surface 130 of the retractor shoe 126 moving the shoe linearly rearward. The shoe's rearward bearing surface 132 engages the first hub lever tab 139 to pivot the hub lever 128 in a counterclockwise direction as seen in FIG. 24 . The portion of the upper leg of 138 of the hub lever 128 acts against the retraction surface 92 of the tail plate 68 to move the tail plate and connected latch bolt 46 to the retracted position.
The present invention is also concerned with the locking mechanism (FIG. 2) for selectively securing one or both of the retractor hubs 108 from rotation. The locking mechanism comprises an elongated slide plate 142 and the toggle 52 . Referring to FIG. 20, the rearward end 144 of the slide plate 142 has two slots 146 for receiving a portion of the hubs 108 adjacent the respective bosses 114 . Both ends 144 , 145 of the slide plate 142 have opposed lateral tabs 148 , 149 which ride in corresponding slots 150 in the side walls 34 , 36 of the case for guiding and supporting linear movement of the slide plate 142 relative to the hubs 108 . Each rear plate tab 148 has a transverse hole 152 which opens into the slots 146 . The holes 152 are preferably threaded for receiving a blocking screw 154 . The screw 154 is sufficiently long so that when the screw 154 is threaded into the tab 148 the screw extends into the slot 146 .
The slide plate 142 is cooperatively linked to the toggle 52 which is accessible through the opening in the front wall 42 and face plate 54 . Manipulation of the toggle 52 linearly reciprocates the slide plate 142 relative to the hubs 108 between an unlocked position (FIGS. 20 and 21) and a locked position (FIGS. 22 and 23 ). The locking mechanism is moved to the locked position by depressing the upper end of the toggle 52 thereby moving the slide plate 142 so that the rearward end 144 is positioned adjacent the hubs 108 . When the locking mechanism is in the locked position, the screw 154 is in the path of the boss 114 on one of the retractor hubs 108 thereby preventing rotation of the hub 108 . As noted above, the hub 108 preferably affected by the locking mechanism is on the outside of the door. Therefore, the screw 154 is preferably placed in the rear slide plate tab 148 corresponding to the outside hub 108 so as to prevent rotation of the outside hub and retraction of the latch bolt 46 from the outside when the lock is locked. The inside hub 108 can still turn to permit retraction of the latch bolt 46 since the hub boss 114 passes freely through the open slot 146 in the slide plate 142 . If the mortise lock is reversed for installation in a door of the opposite hand, the screw 154 is simply moved to the opposite rear tab 148 . Of course, in mortise locks using a single hub, the screw prevents rotation of both operators. Similarly, in the illustrated embodiment, a second stop screw can be used with the same effect. The locking mechanism is unlocked by depressing the lower end of the toggle 52 thereby moving the slide toward the front wall 42 of the case 32 and away from the hubs 108 (FIGS. 20 and 21 ).
Preferably, the mortise lock assembly includes the deadbolt 48 and the auxiliary bolt 50 . The deadbolt 48 is selectively moved between an extended position and retracted position by operation of a key cylinder or thumb turn (not shown) in a conventional manner. The cylinder and thumb turn rotate a deadbolt lever 156 which engages the sides of a slot 158 in the rearward end 160 of the deadbolt 48 for extending or retracting the deadbolt. The upper leg 138 of the hub lever 128 has a second laterally projecting tab 162 for engaging the deadbolt lever 156 when the deadbolt 48 is in the extended position for retracting the deadbolt along with the latch bolt 46 in response to rotation of either hub 108 (FIG. 24 ).
A rotating stop lever 164 is provided for functionally connecting the deadbolt lever 156 and locking mechanism (FIG. 2 ). The lower end 166 of the stop lever 164 is positioned in a slot 168 in the slide plate 142 and the upper end 170 is arranged in the path of the deadbolt lever 156 . When the deadbolt 48 is moved from the retracted position to the extended position the deadbolt lever 156 engages the upper end portion 170 of the stop lever 164 to rotate the lever in a clockwise direction (as seen in FIG. 2) and move the locking mechanism, including the side plate 142 and toggle 52 , to the locked position. Thus, the locking mechanism automatically moves to the locked position when the deadbolt 48 is moved to the extended position. The locking mechanism remains in this position, even when the deadbolt 48 is retracted by operation of one of the hubs 108 (FIG. 24 ), until the toggle 52 is actuated to move the slide plate 142 away-from the hubs 108 . When the deadbolt 48 is moved from the retracted position to the extended position the deadbolt lever 156 engages the upper end portion 170 of the stop lever 164 to rotate the lever in a clockwise direction (as seen in FIG. 2) and move the locking mechanism, including the side plate 142 and toggle 52 , to the locked position. Thus, the locking mechanism automatically moves to the locked position when the deadbolt 48 is moved to the extended position. The locking mechanism remains in this position, even when the deadbolt 48 is retracted by operation of one of the hubs 108 (FIG. 24 ), until the toggle 52 is actuated to move the slide plate 142 away from the hubs 108 .
Means for deadlocking the latch bolt 46 in the extended position is also provided (FIG. 2 ). The deadlocking means 172 comprises the auxiliary bolt 50 , a deadlocking lever 174 and an auxiliary latch lever 176 . When the door is closed, the auxiliary bolt 50 is depressed by the door frame which allows the deadlocking lever 174 to pivot in a counterclockwise direction under the biasing force of a compression spring 178 to a position where the deadlocking lever prevents manual depression of the latch bolt 46 . The deadbolt 48 also has a shoulder 180 which is adjacent the rear surface of the bolt head 58 when the deadbolt is extended also for preventing depression of the latch bolt 46 .
The previously described embodiments of the present invention have many advantages, including the provision of a reversible mortise lock which cannot be tampered with after installation. Moreover, because the latch bolt reversal relies on removal of the entire latch bolt from the case rather than partial removal, the bolt head can be as long as is practical thereby providing greater strength and security for the lock. The mortise lock incorporating the new latch assembly and locking mechanism is easily modified from outside of the lock casing with a screw driver for use with either a right-hand door or a left-hand door. In either arrangement, the latch operators are operable to open the door when the lock is unlocked. When the lock is locked, rotation of the outside latch operator is prevented, whereas the inside latch operator is still operable to open the door. With the addition of another blocking screw, the inside latch operator can also be locked against rotation.
Although the present invention has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, a single rollback hub can replace the two, independent hubs so that the locking mechanism affects both the inside and outside latch operators. Accordingly, we intend to cover all such modifications, omission, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. | A reversible mortise lock comprises a latch bolt which is removable from the housing for ease of reversal. A securing member is disposed inside the lock housing for releasbly holding the latch bolt in the housing. The securing member includes a securing element having a blocking surface biased into engagement with the latch bolt for securing the latch bolt to the securing member. The securing element has a surface accessible from outside the lock housing which when pressed releases the latch bolt from the securing member. Once the latch bolt is freed, the latch bolt can be completely removed from the lock housing, reversed and reinstalled. This releasing surface is only accessible through the side walls of the lock housing. Therefore, latch bolt reversal must be performed before the lock is installed in a door. Once the lock is installed, the latch bolt cannot be reversed because the latch bolt cannot be removed from the lock. A locking mechanism for use in the lock comprises a blocking element in the housing and a toggle for manually moving the blocking element between a locked position and an unlocked position relative to a latch operator. A stop is removably attached to the blocking element and adapted in the locked position to prevent operation of the outside latch operator. The stop is also accessible through the side walls of the lock housing and positioning of the stop in the blocking element is accomplished before installation. Preferably, the stop is a threaded plug which is received in a threaded opening in the blocking element. Thus, a screw driver is the only tool needed to release the latch bolt from the lock housing for reversal of the latch bolt and locking mechanism. | 4 |
BACKGROUND OF THE INVENTION
The present invention is directed to an improvement in key rings for retaining one or more keys on each of one or two keyholders. More specifically, the present invention relates to an improved, double ended key ring for retaining a key holder and having a unique release means for detachably removing at least one of the keyholders.
Conventional double ended key rings typically employ a pair of keyholders positioned at opposite ends of a central housing. Keys may be segregated and one or more keys placed on each of the keyholders; one or perhaps both of the keyholders is removably secured to the key ring thereby enabling the user of the keys to selectively remove keyholders (or even keys) from the double ended key ring easily.
For example, automobile keys may be placed on one end of a double ended key ring and house keys may be placed on the other end of a double ended key ring to maintain those keys as separate. Examples of conventional double ended key rings are illustrated in MacDonald U.S. Pat. Des. Nos. 271,443 of Nov. 22, 1983 and Des. 285,987 of Oct. 7, 1986.
Typical prior art double ended key rings are illustrated in U.S. Pat. No. 2,916,907 to Bridwell, U.S. Pat. No. 3,957,591 to Nadell and U.S. Pat. No. 4,821,543 to Scungio.
None of the key rings described or illustrated in the aforementioned patents provides a substantially concealed, nonobtrusive release mechanism for removing keys (or keyholders) from a key ring.
Thus there is a need for a fast, reliable, inexpensive releasing means for key rings and, in particular, for double ended key rings.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of the prior art by providing a new, unique and improved releasable key ring.
The present invention includes a key ring, preferably a double ended key ring, comprising a housing which is open at the top and a cover pivotably mounted relative to the housing. The cover and housing have an engaged position and an open position, and are pivotable relative to each other between the engaged and open positions. The cover and housing have an opening therebetween for retaining one or more keys (or more or more keyholders) and when the cover and housing are in the open position access is provided to the opening. When the cover and housing are in the engaged position access to the opening is prevented. A cover biasing means urges the cover into the open position and a latch is provided in the housing for maintaining the cover in the engaged position against the cover biasing means. Means are provided for releasing the latch and, in a preferred embodiment, the latch releasing means is part of the latch itself.
BRIEF DESCRIPTION OF THE DRAWINGS
The various objects of the present invention, together with other advantages and benefits which may be attained by its use, will become more apparent upon reading the following detailed description of the invention taken in conjunction with the drawings.
In the drawings, wherein like reference numerals identify corresponding ,parts of the invention:
FIG. 1 is a perspective illustrated of a double ended key ring according to the principles of the present invention;
FIG. 2 is an exploded front elevation view of the present invention; and
FIG. 3 is a partial perspective exploded illustration of a portion of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 of the drawings, a double ended key ring 10 is illustrated having a keyholder 12, 14 mounted at each end of the double ended key ring 10. A key 16 is illustrated as being mounted on the keyholder 12 and a key 18 is illustrated as being mounted on the keyholder 14.
The double ended key ring 10 includes a housing 20 and a cover 22 pivotably mounted relative to the housing.
With reference to the exploded illustrations of FIGS. 2 and 3, the housing 20 is illustrated as a generally rectangular, partially hollow box having flat front and rear faces, a first or bottom end 24, a second or top end 26 and opposed sides 28, 30. At the top end, the front and rear surfaces extend to form two pairs of laterally spaced apart ears or projections 32, 34, each pair being at one side of the housing.
The housing includes a first longitudinal bore 36 extending almost the full height of the housing, commencing at the top end 26 (opening between one pair of ears 32), and extending downwardly toward the first end 24 adjacent one side 28 of the housing. A semicircular recess 38 is provided interiorly of the housing at the second side 30. This recess 38 communicates with a bore 40 which extends substantially across the housing in a direction generally transverse to the longitudinal bore 36.
At the first end or bottom 24 of the housing a short bore 42 is provided with an axis generally parallel to the axis of bore 36. A slight depression or curved notch 44 is provided in the front and rear faces of the housing extending inwardly from the second side 30 near the vertical bottom of the recess 38.
A pair of aligned apertures 48 is provided through the front and rear housing faces generally in the center of each of the first pair of ears 32 and transversely thereof. A second pair of aligned apertures 50 is provided through the front and rear faces extending transversely through the recess 38. An aperture 52 is provided through the front face of the housing adjacent first end 24 in communication with bore 42.
The cover 22 is a generally thin, flat, solid C-shaped member having a base or top 54 and opposed legs 56, 58. Depending downwardly from the legs 56, 58 are a pair of projections 60, 62, respectively. The projections are of a reduced thickness, front to back, compared to the thickness of the remainder of the cover 22, and the underside 61 of projection 60 is inclined. The thickness and width of projection 60 is such that it fits between the pair of ears 32. The thickness and width of projection 62 is such that it fits between the second pair of ears 34. The facing interior surfaces of the projections 60, 62 and of the ears 32, 34 are curved and with the cover assembled to the housing with projections 60, 62 between their associated pairs of ears a generally rectangular opening with flat sides and curved ends is defined therebetween.
Means are provided for biasing the cover into an open position relative to the housing. Specifically, a compression spring 64 is placed within the bore 36 and a bearing rod 66, having an enlarged head 68 which functions as a bearing surface, is inserted into the bore 36 after the spring 64 has been placed within the bore. The enlarged head 68 of the rod, and more particularly the top of the head 68 will bear against the underside of the projection 60 such that when the cover 22 is pivotably mounted relative to the housing, the force of the compression spring on the rod 66 is transferred to the inclined bottom 61 of the projection 60 to urge the cover into an open position relative to the housing.
Means are provided for pivotally mounting the cover and housing relative to each other. Specifically, an aperture 70 is provided through the projection 60 and a pivot pin or rod 72 is provided. The diameter of aperture 70 is preferably larger than the diameter of pin 72 and aperture 48 such that when projection 60 is inserted between ears 32 and apertures 48 and 70 aligned, pin 72 may be inserted through apertures 48 and 70 so as to pivot the cover and housing together. The pin may be force fit into aperture 48. Alternate fastening is, of course, feasible.
Means are provided to latch the housing and cover in the engaged position to close the opening therebetween and for selectively releasing the latch. With reference to the drawings, and in particular FIGS. 1 and 2, the latch means and latch release means includes an elongated, thin rectangular latch bar 74 having a semicircular protuberance 76 on one side intermediate the opposite ends of the latch bar. An aperture 78 is provided transversely of the protuberance. A first end 80 of the latch bar includes a tooth 82 formed of an inclined surface which tooth extends laterally of the latch bar on the same side thereof as the protuberance 76. A compression spring 84 is provided and with the spring 84 positioned in the bore 40, the latch bar protuberance 76 may be inserted within the recess 38 until apertures 50 and 78 are aligned. Thereafter, a pivot pin or rod 86 is force fit into aperture 50 and through the slightly larger diameter aperture 78 to pivotally secure the latch bar 74 relative to the housing. In the orientation illustrated in FIGS. 1, 2, and 3 the spring 84 urges the latch bar counterclockwise. The projection 62 includes a slot 88 configured to receive the tooth 82 such that when the key ring is assembled as described the cover 22 may be pivoted clockwise relative to the housing such that the projection 62 moves between the pair of ears 34. The projection 62 bears against the inclined surface of the tooth 82 to move the latch bar 74 clockwise against the force of the compression spring 84 until the cover 22 is completely closed relative to the housing. At that time, spring 84 urges the latch bar counterclockwise such that the tooth 82 engages the slot 88. In this closed or engaged position there is no access to the elongated opening between the cover and housing.
The key ring of the present invention includes a rotatably mounted connector 90 having a bore 92 therethrough to receive a keyholder 14. The connector 90 is a generally cylindrical member having a reduced diameter portion 94 with a circumferential groove 96 therein. The reduced diameter portion 94 is configured to be of slightly smaller diameter than the diameter of bore 42 such that the reduced diameter portion of the connector may be inserted into the bore 42 until the circumferential groove 96 is aligned relative to the aperture 52. A pin 98 may thereafter be force fit through the aperture 52 into the reduced groove 96 such that the connector 90 is rotatably secured to the housing but longitudinal movement is precluded.
The operation of the key ring of the present invention will now be explained. With the key ring in the engaged position as illustrated generally in FIG. 1, if it is desired to remove the keyholder 12, the latch bar 74 is moved clockwise by external pressure exerted toward the first side 28. This may be conveniently done by pressing against the latch bar 74 and, as the latch bar pivots in a clockwise direction, the semicircular depression 44 would accommodate the thumb or finger of a person utilizing the key ring of the present invention.
In response to the clockwise movement of the latch bar, tooth 82 is disengaged from slot 88 and the cover 22 pivots in a counterclockwise direction under the urging of the biasing spring 64. This provides access to the opening such that the keyholder 12 may be removed. In this fashion, keys such as automobile ignition keys may remain with the vehicle while house keys may be retained by the user of the key ring. Spring 84, of course, urges the latch bar back to a vertical position as soon as the external pressure on the latch bar is released.
After the keyholder 12 has been removed (or replaced within the opening) the cover 22 is manually pivoted in a clockwise direction against the bias spring 64, until the projection 62 bears against the tooth 82 temporarily causing the latch bar to pivot clockwise until the projection 62 is seated between the pair of ears 34 at which time the spring 84 will urge the latch bar counterclockwise until the tooth 82 engages the slot 88 in the projection 62.
It should be appreciated that in lieu of a keyholder, an actual key may be engaged within the opening if the key has a sufficiently large aperture therein.
In the embodiment of the present invention, each of the springs are preferably stainless steel and the other components are brass. After the key ring is assembled, conventional metal finishing is employed such as sanding (tumbling), polishing and decorative plating. The key ring may be made of other strong or rigid materials such as plastics, wood, etc. The housing may, of course, be embossed with a trademark or a logo of an automobile manufacturer or with other decorative designs. The various directions such as top, bottom, clockwise, etc., are purely for illustrative purposes.
The foregoing is a complete description of the preferred embodiment of the present invention. Numerous changes may be made without departing from the spirit and scope of the present invention. The invention, therefore, should be limited only by the following claims. | A double ended key ring includes a housing and a cover which are pivotally connected. A bias mechanism urges the housing and cover into an open position thereby providing access to an opening therebetween for mounting or removing keys or keyholders. A latch mechanism is pivotally mounted relative to the housing for releasably holding the cover in the closed position. The entire bias mechanism and the latch mechanism is effectively concealed when the key ring is in the engaged or closed position, in which position the removal of keyholders is precluded. | 0 |
[0001] The present application claims priority to U.S. provisional application Ser. No. 60/710,354, filed on Aug. 22, 2006, entitled Sensors On Patrol (SOP): Using Mobile Sensors for Environmental Monitoring, to Tao Zhang, et al., the entire disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present application relates generally to wireless networking, and more particularly to systems and methods for supporting the use of mobile devices as sensors to detect various types of environmental conditions and situations, such as weather and traffic conditions, as well as potential biological, chemical or other types of hazards, together with advanced handover (handoff) operations whereby such mobile devices may connect to different wireless networks and/or wireless network access points as needed to maintain continuity of connectivity of the mobile sensor devices with a host control or command center.
[0004] 2. General Background Discussion
[0000] A. Environmental Monitoring
[0005] Environmental sensors have been developed to monitor conditions such as potential biological and chemical attacks, air quality, road conditions, traffic accidents, and so on. For example, flame detectors monitor and analyze incident radiation at selected wavelengths to determine the existence of a fire. Humidity sensors test for absolute humidity, relative humidity, or dew point in air. Moisture sensors are used to measure the moisture content in gases. Photometers and calorimeters, water quality sensors, are ion-specific computer-interfaced probes designed to determine the concentration of a solution from its color intensity. Radiation sensors are used for medical diagnoses, radioactive dating measurements, and measurements of background radiation, activity levels and radiation doses. Smoke detectors (e.g., ionization chambers and photoelectric smoke detectors) are designed to sense the products of combustion. Solar radiation sensors measure the spectral range of radiation, including global solar radiation, net solar radiation and the photosynthetic light spectrum. Temperature sensors are used to measure the temperature. UV sensors are used to detect ultraviolet power or intensity. Opacity sensors, dust sensors and visibility sensors measure the amount of light transmitted through a sample. Weather sensors are designed to measure one or multiple components of weather including wind speed and direction, rain or snow fall, solar radiation, temperature, pressure and humidity.
[0006] Many cities are deploying or considering the deployment of sensors to monitor the environment. Today, a typical approach is to deploy fixed sensors at selected geographical positions of interest. This works well when each sensor can sense a large geographical area. However, many environmental sensors can typically sense only a small area. As a result, a large number of fixed sensors are needed to cover a large city. This also means that a large and complex network infrastructure is required to connect all the sensors to monitoring centers. Furthermore, fixed sensors are prone to tampering. Accordingly, there exists a need in the art for improvement in environmental monitoring and reporting.
[0000] B. Wireless Networks
[0007] Wireless networks can incorporate a variety of types of mobile devices, such as cellular and wireless telephones, PCs (personal computers), laptop computers, wearable computers, cordless phones, pagers, headsets, printers, PDAs (personal digital assistants), etc. Mobile devices may include digital systems to secure fast wireless transmissions of voice and/or data.
[0008] Wireless LANs (WLANs) in which a mobile user can connect to a local area network (LAN) through a wireless connection may be employed for wireless communications. Wireless communications can include communications that propagate via electromagnetic waves, such as light, infrared, radio, microwave. There are a variety of different WLAN standards that currently exist, such as Bluetooth, IEEE 802.1 1, and HomeRF.
[0009] For example, Bluetooth products may be used to provide links between mobile computers, mobile phones, portable handheld devices, personal digital assistants (PDAs), and other mobile devices and connectivity to the Internet. Bluetooth is a computing and telecommunications industry specification that details how mobile devices can easily interconnect with each other and with non-mobile devices using a short-range wireless connection. Bluetooth creates a digital wireless protocol to address end-user problems arising from the proliferation of various mobile devices that need to keep data synchronized and consistent from one device to another, thereby allowing equipment from different vendors to work seamlessly together. Bluetooth devices may be named according to a common naming concept. For example, a Bluetooth device may possess a Bluetooth Device Name (BDN) or a name associated with a unique Bluetooth Device Address (BDA). Bluetooth devices may also participate in an Internet Protocol (IP) network. If a Bluetooth device functions on an IP network, it may be provided with an IP address and an IP (network) name. Thus, a Bluetooth Device configured to participate on an IP network may contain, e.g., a BDN, a BDA, an IP address and an IP name. The term “IP name” refers to a name corresponding to an IP address of an interface.
[0010] Similarly, IEEE 802.11 specifies technologies for wireless LANs and devices. Using 802.11, wireless networking may be accomplished with each single base station supporting several devices. In some examples, devices may come pre-equipped with wireless hardware or a user may install a separate piece of hardware, such as a card, that may include an antenna. By way of example, devices used in 802.11 typically include three notable elements, whether or not the device is an access point (AP), a mobile station (STA), a bridge, a PCMCIA card or another device: a radio transceiver; an antenna; and a MAC (Media Access Control) layer that controls packet flow between points in a network.
[0011] Wireless networks also may involve methods and protocols found in Mobile IP (Internet Protocol) systems, in PCS systems, and in other mobile network systems. With respect to Mobile IP, this involves a standard communications protocol created by the Internet Engineering Task Force (IETF). With Mobile IP, mobile device users may move across networks while maintaining their IP Address assigned once. See Request for Comments (RFC) 3344. Mobile IP enhances Internet Protocol (IP) and adds means to forward Internet traffic to mobile devices when connecting outside their home network. Mobile IP assigns each mobile node a home address on its home network and a care-of-address (CoA) that identifies the current location of the device within a network and its subnets. When a device is moved to a different network, it receives a new care-of address. A mobility agent on the home network can associate each home address with its care-of address. The mobile node can send the home agent a binding update each time it changes its care-of address by using a protocol such as Internet Control Message Protocol (ICMP).
[0012] In basic IP routing, routing mechanisms typically rely on the assumptions that each network node always has a constant attachment point to the Internet and that each node's IP address identifies the network link it is attached to. In this document, the terminology “node” includes a connection point, which can include a redistribution point or an end point for data transmissions, and which can recognize, process and/or forward communications to other nodes. For example, Internet routers can look at an IP address prefix or the like identifying a device's network. Then, at a network level, routers can look at a set of bits identifying a particular subnet. Then, at a subnet level, routers can look at a set of bits identifying a particular device. With typical mobile IP communications, if a user disconnects a mobile device from the Internet and tries to reconnect it at a new subnet, then the device has to be reconfigured with a new IP address, a proper netmask and a default router. Otherwise, routing protocols would not be able to deliver the packets properly.
[0000] C. Handovers (Handoff) of Mobile Devices
[0013] In the context of a mobile device with an IP-based wireless network interface, the mobile device needs to perform roaming or handovers when it moves from one network to another network, or from one access point of a network to another, in order to maintain session continuity, thus making it imperative for a mobile device to find immediately an appropriate point of network attachment and remain connected to ensure session continuity. With existing handover methodologies, handover is typically accomplished by performing the following sequence of protocol layer specific handovers:
First, handover takes place at the physical layer. In this regard, the mobile device switches its radio channel to a wireless base station or wireless access point in the target network. Second, handover takes place at layer-2. In this regard, the mobile device switches its layer-2 (i.e., link-layer) connections to the target network. As explained above, the link layer or layer-2 refers to the protocol immediately below the IP-layer that carries user traffic. The mobile device performs layer-2 authentication with the target network if the target network requires such authentication. Third, handover takes place at the IP-layer. In this regard, the mobile device obtains a local IP address from the target network, performs IP-layer authentication if required by the target network, and then performs IP-layer location update so that IP packets destined to the mobile device can be routed by the IP network to the mobile device via the target network. In some instances, one way to support IP layer location update is to use Mobile IP defined by the Internet Engineering Task Force (IETF). Fourth, handover takes place at the application-layer. The mobile device performs necessary steps at the application layer to ensure that its application traffic will flow correctly to the applications on the mobile device via the target network. For example, when the mobile device uses the Session Initiation Protocol (SIP) defined by the IETF to manage its application-layer signaling, an application layer handover can be achieved by the mobile device updating its current location with its home SIP server. The mobile device may also need to carry out application-layer authentication with the target network if required by the target network. This is the case, for example, when the mobile device is using the IP Multimedia Subsystem (IMS) in a visited 3GPP (3 rd Generation Partnership Project) wireless network, where the IMS is a SIP-based system supporting application-layer signaling and management for multimedia applications over 3GPP networks.
D. Network Discovery, Media Independent Information Servers, and Handovers
[0018] Network Discovery refers to the identification of an appropriate point of network attachment that meets the application requirements and the characteristics of the mobile device, in a timely, accurate and efficient manner. It is important for the mobile device to obtain this network information before it becomes necessary to carry out a handover or connectivity transfer operation. Network information is any information that is used by a mobile device for identifying networks, accessing networks, and seamlessly transitioning from one network connection to another. The mobile device's network connections may be homogeneous (e.g., access points belonging to the same network) or heterogeneous (e.g., access points belonging to different networks). With the proliferation of wireless network service providers, seamless handover across heterogeneous networks is becoming as important as handover between homogeneous networks. However, heterogeneous handover requires the following key capabilities:
Quick Network Discovery: To discover the most up-to-date and accurate information about the existence and availability of networks and information regarding the networks to which the mobile device may connect in a handover operation. Quick Selection of Candidate Networks: To quickly select one network that the mobile device will prefer to use, when multiple networks are available at the same time.
[0021] With Network Discovery, Proactive Handover Actions can be enabled. Proactive handover actions refer to performing some or all of the required handover actions before the mobile device is actually handed over to a target network to reduce delay and possible session discontinuity. For example, the mobile device may pre-acquire a local IP address and perform pre-authentication with a target network while still connected to a first network, so that when the time comes for the handover, the mobile is already assigned a valid IP address and already is authenticated with the target network.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0022] The preferred embodiments of the present invention fulfill the existing need as explained above, by providing systems and methods for environmental monitoring and detection by using mobile sensors to patrol an area of interest and relay collected data substantially in real time to a command center. According to one aspect of the present invention, mobile sensors are mounted on public vehicles (e.g., buses, taxis, police cars, trains, trucks) and are worn or carried by public personnel (e.g., policemen, fire fighters, mail carriers, emergency response personnel) to monitor the environment. A vehicle or person that carries a mobile sensor will be referred to as a Sensor Carrier. The mobile sensors or the Sensor Carriers can be equipped with geographical location determination devices (e.g., the Global Positioning System or GPS) so that they can map the environmental data collected to geographical locations.
[0023] The Mobile Sensor System (MSS) can co-exist with fixed sensors. MSS can be used to monitor areas which are frequently traveled by Sensor Carriers and fixed sensors can be used only in areas where few vehicles and/or people travel to or sub-areas which cannot be easily sensed by vehicle-mounted or wearable sensors.
[0024] MSS can reduce the number of sensors required to cover a given geographical area, and also reduce the size and complexity of the network infrastructure for connecting sensors to monitoring command centers. Rather than having to connect a large number of fixed sensors over a potentially large geographical region, a smaller number of wireless local-area networks (WLANs), such as those using IEEE 802.11 (WiFi) or IEEE 802.16 (WiMax), can be established in selected locations in the region of interest for the mobile sensors to report the information they collected to monitoring centers when these mobile sensors move through the WLANs.
[0025] In conjunction with the mobile sensing of environmental conditions and situations, it is important to have information about neighboring wireless networks that a mobile user may enter so as to enable a mobile sensor device to implement advanced capabilities to better support mobility and mobile applications. For example, knowing the addresses of the address servers and the authentication servers in a neighboring network may allow a mobile sensor device to acquire a local Internet protocol address from, and authenticate with, the neighboring network before the mobile actually enters the radio coverage area of the neighboring network. This can significantly reduce handover delays. In other words, to support such proactive handover mechanisms, the mobiles need to be able to discover the neighboring networks and their parameters ahead of time. This can be achieved if, for example, other communications devices that previously visited the networks reported the information they collected to a Knowledge Server (such as a MIIS as described above) so that any mobile device can later query such Knowledge Server to find the information about the neighboring networks at their current locations.
[0026] The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages where applicable. In addition, various embodiments can combine one or more aspect or feature of other embodiments where applicable. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The preferred embodiments of the present invention are shown by a way of example, and not limitation, in the accompanying figures, in which:
[0028] FIG. 1 is a schematic diagram of one embodiment of a mobile sensor device system according to the invention, utilizing multiple “roadside” wireless LANs;
[0029] FIG. 2 is a schematic diagram illustrating one method of dividing a geographic region of interest into a plurality of sub-areas for sensor coverage calculations;
[0030] FIG. 3 is a graph showing the number of mobile sensors needed as a function of the number of sub-areas into which a region of interest is divided; and
[0031] FIG. 4 is a flow diagram of an algorithm according to one aspect of the invention that sorts collected environmental data from the mobile sensor devices into critical data and stable data categories.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] In accordance with one aspect of the present invention, advantage is taken of the natural mobility of vehicles and people that routinely move throughout a geographical region by supplying such vehicles and/or people with mobile sensors as they move about in such regions. A vehicle or person that carries a Mobile Sensor will be referred to as a Sensor Carrier.
[0033] The term “sensor” in this document is used in its most general sense. Any type of sensors may be used. These include, for example, sensors that can be used to detect potential nuclear, biological, chemical or other types of airborne hazards. Any communication device may be used as a sensor to collect (i.e., “sense”) information about the networks they visit. Such information may include the location, type, capabilities of networks, network elements (e.g., wireless access points, routers, IP address servers, network authentication servers, and application servers), and their properties (e.g., addresses and information needed to access these network elements). They can also collect user information contents available on the networks. The mobile devices can map the network information they collected to geographical coordinates and report the information to the Knowledge Server. Specially designed “network sensors” can also be mounted on mobile vehicles or carried by people and used to collect the network information described above.
[0034] Referring to FIG. 1 , monitoring the environment along a city street is shown as an example to illustrate the principles and operations of the invention. In one preferred embodiment, mobile sensors monitor the area of interest (e.g., a street), as the Sensor Carriers move about. For example, as taxis move down a street, sensors mounted on the taxis monitor their surroundings continuously. Sensors report the information they collect to a processing center, for example to a Knowledge Server as shown in FIG. 1 . Users, such as policemen, emergency management personnel, and environmental monitoring agencies can then query the Knowledge Servers for information collected from the sensors. Users and computer programs can also query the mobile sensors directly over wireless networks.
[0035] A small number of wireless LANs, such as WiFi LANs (IEEE 802.11), can be deployed at selected locations and positions along a street to be used by the mobile sensors to transmit their collected data. Key factors that impact the number of required wireless LANs include the required sensor information reporting frequency, the size of the geographical area to be monitored, and the velocity and mobility patterns of the Sensor Carriers inside the area. The frequency with which a sensor reports its findings depends on the requirements of the specific applications that use the sensor data. Depending on the required sensor information reporting frequency, the wireless LANs may not need to cover the entire street and a sensor may or may not need to report its findings at every roadside WiFi LAN it traverses.
[0036] The roadside wireless LANs can also be used for a processing center to support other mobile sensor-based networking capabilities and applications, such as:
Remote configuration of the sensors. For example, the frequency with which sensors report information can be changed, and selected sensors can be turned on or off remotely; Proactively polling the mobile sensors that pass through a wireless LAN to collect sensor data; Sending alerts to vehicles and people who pass through the wireless LANs based on sensor the collected sensor information.
[0040] One important issue in accordance with the MSS of the present invention is how many Sensor Carriers will be required in a given geographical area so that each position of interest in the region can be sensed at a minimum required frequency, which will be referred to as the required Sensing Frequency. One approach according to the invention for determining the minimum number of sensor carriers needed to meet a given sensing frequency for a given geographical region is based on the observation that it is generally easier to determine the number of Sensor Carriers required to cover a small and regular area than a large and random area. Therefore, one basic approach is as follows:
[0041] Step 1: Decompose the original, and potentially large, geographical region of interest such as a city, into n smaller sub-areas so that:
The number K of Sensor Carriers required to meet the sensing frequency inside each sub-area can be easily determined, and The value of K is roughly identical for each sub area.
[0044] Step 2: Compute the value of K for each sub-area.
[0045] Step 3: Compute the minimum number S(n) of Sensor Carriers required so that there will be at least one sensor carrier inside each sub-area.
[0046] Step 4: The minimum total number S of Sensor Carriers required to meet the required sensing frequency in all sub-areas can then be computed as S=K*S(n).
[0047] Methods for estimating the value of K and for estimating S(n) will now be described.
[0000] A. Methods for Determining the Value of K
[0048] This section first describes methods for estimating the number K of sensor carriers required to meet the sensing frequency for each sub-area. It then discusses how to estimate the number W of wireless LANs required to be deployed inside the sub-area to meet a given sensor information reporting frequency.
[0049] The decomposition of a given region into n sub-areas so that each sub-area will need roughly the same number K of sensor carriers generally depends on factors that are specific to the given geographical region. For example, it may depend on how frequently each area within the given region is traveled by the potential Sensor Carriers.
[0050] Using Manhattan, which is part of New York City, as an example, FIG. 2 illustrates how to decompose the given region and how to compute the value of K. As shown in FIG. 2 , Manhattan is naturally divided into streets that go east and west and avenues that go north and south. The section of each street between two adjacent avenues, and the section of each avenue between two adjacent streets, is called a block.
[0051] To determine the number of Sensor Carriers needed to cover Manhattan, the blocks can be treated as sub-areas. Alternatively, we can treat the streets and avenues as the sub-areas. Given the traffic conditions in Manhattan, one can estimate the average time it may take a vehicle to traverse a sub-area. In Manhattan, the street blocks are typically between 250 to 300 meters long and the avenue blocks are much shorter. Hence, given average vehicle speeds, one can estimate the time it takes for a vehicle to traverse a block.
[0052] We denote by Δ the average sensing interval, which is the inverse of the sensing frequency, for each specific point of interest inside a sub-area. If T is the average time in minutes it takes one Sensor Carrier to traverse a sub-area, the average sensing interval Δ for each point of interest inside a sub-area will be T minutes when only one sensor carrier roams inside the sub-area. With K sensors in a sub-area, the average sensing interval Δ for the sub-area can be estimated as Δ≅T/K. Therefore, for a given target sensing interval Δ and the value of T, we can easily derive the value of K.
[0053] Assume that K sensor carriers are roaming randomly inside a sub-area. For a given sensor information reporting frequency F r (in number of reports per minute), the number W of required wireless LANs in the sub-area can be estimated as W≅T*F r /K
[0054] B. Methods for Estimating S(n) A method for estimating S(n), the minimum number of sensor carriers needed so that there will be at least one sensor carrier in each of the n sub-areas, will now be described. We assume that at any given time all Sensor Carriers are distributed in the n sub-areas uniformly at random. Then, the problem becomes one of determining the minimum number S(n) of balls one has to throw randomly into n urns before each urn contains at least one ball. The balls correspond to the Sensor Carriers and the urns correspond to the n sub-areas.
[0055] Let S(j) be the minimum number of sensor carriers required so that at least one sensor carrier will be in each of j sub-areas. Suppose that a minimum of M(j) additional sensor carriers will be needed so that one new sub-area will have at least one sensor carrier. Then we have,
S ( n )= S ( n− 1)+ M ( n− 1)
S ( n− 1)= S ( n− 2)+ M ( n− 2)
.
.
.
S (2)= S (1)+ M (1)
S (1)=1
[0056] The probability that one additional Sensor Carrier will be sufficient for the value of M(j) to be 1 will be 1/n. The probability that only the second additional sensor carrier can make the value of M(j) to be 1 will be (1−1/n)(1/n). The probability that only the third additional sensor carrier can make the value of M(j) to be 1 will be (1−1/n)(1−1/n)(1/n), and so on. Therefore, M(n−1) can be calculated as follows
M ( n - 1 ) = 1 1 n + 2 · n - 1 n · 1 n + 3 ( n - 1 n ) 2 1 n + 4 ( n - 1 n ) 3 1 n + ⋯ = 1 n { 1 + 2 ( n - 1 n ) + 3 ( n - 1 n ) 2 + 4 ( n - 1 n ) 3 + 5 ( n - 1 n ) 4 + ⋯ } = 1 n n 2 = n
Similarly, we can derive that:
M ( k ) = 1 n - k n + 2 ( k n ) ( n - k n ) + 3 ( k n ) 2 ( n - k n ) + 4 ( k n ) 3 ( n - k n ) + ⋯ = ( n - k n ) { 1 + 2 ( k n ) + 3 ( k n ) 2 + 4 ( k n ) 3 + ⋯ } = n n - k
[0057] S(n) can be derived as follows:
S ( n ) = n n - 1 + n n - 2 + n n - 3 + n n - 4 + ⋯ + n = n ( 1 + 1 2 + 1 3 + ⋯ + 1 n - 1 ) ( 1 )
[0058] Based on Equation (1), S(n) can be estimated as in Equation (2) when n is very large,
S ( n )≦ n lg( n ) (2)
[0059] When n is large, the problem of determining the number of Sensor Carriers required so that there will be at least one sensor carrier in every sub-area can also be modeled as the so-called Coupon Collector's Problem. The Coupon Collector's Problem can be formulated as follows: given n bins, how many coupons S(n) on average do we have to throw into the n bins before each bin contains at least one coupon? The n bins correspond to the n sub-areas in our problem and the S(n) balls correspond to the total number of Sensor Carriers needed so that there will be at least one Sensor Carrier monitoring each of the n sub-areas. Formulating the problem in this manner also leads us to the same conclusion as in Equation (2).
[0060] FIG. 3 shows S(n) vs. n for n up to 400. We observe from this figure that if at least one Sensor Carrier is required to be in each of n sub-areas in order to meet the sensing requirement in the sub-areas, a relatively small number of Sensor Carriers will be sufficient for a fairly large number of sub-areas. For example, less than 2450 Sensor Carriers will be sufficient for 300 sub-areas. Taking Manhattan again as an example, the number of taxis alone that roam the approximately 300 streets and avenues are far more than 2450 (there are about 13,000 taxis in New York City, and most of them are in Manhattan).
[0000] C. Data Processing
[0061] In another embodiment of the present invention, as referred in FIG. 4 , a sorting algorithm will sort out the environmental data obtained continuously through the sensors into two categories, which will be given different priorities when the mobile sensors and Sensor Carriers have limited wireless network resources or time to report the data:
[0062] a) Critical Data: Data that lies below or above the standards set by Environmental Protection Agency (EPA) and is absolutely necessary to be conveyed to the knowledge server on real time basis;
[0063] b) Stable Data: That lies within normal range as specified by EPA and is not necessary to be communicated to the knowledge server on real time basis.
[0064] The critical data will be stored in a Transitory Memory and reported to the Knowledge Server immediately through the first WLAN that becomes available on the movement path of the Sensor Carrier. However, the stable data will be stored in a Retention Memory and will be uploaded to the server when the Sensor Carrier still have time and wireless resources after it finishes reporting the critical data or when the Sensor Carrier returns to its home WLAN. The data, if it lies beyond a tolerance limit and needs immediate action can also be routed automatically to an appropriate emergency center based on the geographical location information appended with the data.
[0065] This embodiment will further reduce the number of required wireless LANs deployment because the required sensor information reporting frequency will be reduced.
[0066] While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and that such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
[0000] Broad Scope of the Invention
[0067] While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language present invention or invention should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure, the following abbreviated terminology may be employed: “e.g.” which means “for example.” | Sensors mounted on vehicles (e.g., buses, taxis, police cars) and public personnel (e.g., policemen) are used to monitor various conditions and situations such as air quality, potential biological and chemical attacks, and road and traffic conditions. The invention improves upon the typical approach that deploys fixed sensors at every geographical position of interest. The total number of required sensors and the size and the complexity of the network infrastructure required to connect the sensors are reduced and simplified. A method for estimating the number of mobile sensors required to cover a region of interest also is disclosed. A relatively small number of mobile sensors may be sufficient to cover a large area at a lower cost and less complexity than a fixed sensor network. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a multiple system circular knitting machine having electromagnetic needle selection means whereby the longitudinally shiftable and radially tiltable selecting plate bars or jacks are tilted by a push cam member against the force of a resetting spring to be forwarded in the range of a selection electromagnet at each selection point of the machine.
In circular knitting machines having electromagnetic needle selection there occurred problems as regards the reliability of functioning of the needle selection means when rotary speed of the machine has been increased. In particular, the abrasion of selecting jacks and of selecting cam parts has been found as the source of interferences during the operation of the machine.
SUMMARY OF THE INVENTION
It is therefore a general object of this invention to overcome the disadvantage of prior art knitting machines of this kind and to provide a circular knitting machine having electromagnetic selection wherein the wear phenomena on selecting jacks which might affect the functionability of the electromagnetic needle selection means, are diminished and their negative effect is reduced.
In keeping with this object and others which will become apparent hereafter, one feature of this invention resides in the provision of a common supporting ring surrounding the needle cylinder and supporting the superposed jack cams and needle cams of all knitting systems, the support ring resting on a plurality of radial ribs mounted on a supporting plate secured to the machine frame, each of the selecting electromagnets being mounted on an end portion of an elongated holder which is insertable into the spacing between two radial ribs such that the electromagnet enters a circumferential recess in the needle cylinder opposite the path of movement of end portions of the selecting jacks, the magnet holders being disconnectably secured to the support ring and adjusted in a position at which the assigned electromagnet is located at the corresponding selection point, and the jack cams including for each selection point a pair of axially superposed and circumferentially offset pressure cams which during the rotation of the needle cylinder swing the end portions of the selecting jacks in the working range of respective electromagnets at the selection points.
In a preferred embodiment, the lower one of the pressing cams engages the end portion of the selecting jack first and moves the same radially inwardly at a relatively slow rate to a transfer point before the selection point, and the upper pressing cam taking over the end portion of the selecting jack at the transfer point and moving the end portion at a higher rate in contact with the electromagnet at the selection point.
The construction of the circular knitting machine according to the invention has the advantage that the selecting electromagnet can be inserted, exchanged and most importantly readjusted in position at the selection point without the necessity to remove the corresponding system cam races. One of the two pressure cams executes the major part on the swinging movement of the selecting jacks in the direction against the selecting magnets. The second pressure cam whose position in the cam race preferably is finely adjustable, executes the accurate position adjustment of the end portion of the selecting jack relative to the selecting magnet whereby with advantage it presses the jacks with a slight overpressure against the magnets to such an extent that a slight elastic bending of the end portion of the jack between its fulcrum engaging the bottom of the guiding slot in the needle cylinder and the point of engagement of the jack on the electromagnet will occur. With advantage, the first pressure cam acts on the straight end surface portion of the stem of the selecting jack whereby the opposite surface portion acts as the armature for the magnet. At the same time, each selecting jack which acts as a needle pusher is free to perform without obstacles its movement in longitudinal or axial direction during the swinging movement enforced by the first pressure cam. The second pressure cam acts preferably on a run-on surface of a lift butt formed on the selecting jack at a distance from its lower end portion whereby it also can exert a slight overpressure to cause a certain amount of elastic bowing of the selecting jack.
The area of the selecting jack which is subject to the greatest wear is the surface region of the stem engaging the first pressure cam. In contrast, only a minute wear occurs on the run-on surface of the lift butt of the jacks and on the second cam acting on the lift butts, that means the parts which finely determine the abutment point of the selecting jack on the magnet remain substantially without wear.
With advantage, the region of the needle cylinder at the level of the first pressure cams is provided with a recess in the outer side of the guiding slots in which the first pressure cam can enter. In this manner it is achieved that in this region the butts of the selecting jacks are subject to no load, the selecting jacks are prevented from tilting against lateral walls of the guiding slots and are fully guided by the latter. When the lift butt of the jack contacts the second pressure cam, it has been already partially immersed in the recess between the guiding slots. Accordingly, even with finely divided spacings and with thin guiding webs for the jacks there is no danger of lateral bending of the selecting jacks. Moreover, by virtue of the construction of the two pressure cams installation space is saved in the circumferential area of the systems inasmuch as the radial tilting and the longitudinal shifting of the selecting jacks can partially overlap.
The operational reliability of the needle selection in the circular knitting machine constructed according to the invention can be further increased by providing the circumferential recess in the needle cylinder with a lining or annular jacket of a magnetically nonconductive material which separates the selecting electromagnets at respective selection points from the cylinder. In this manner any magnetic short circuits via the needle cylinder are avoided and the total magnetic energy at the magnet poles is available for acting on the selecting jacks.
The novel arrangement of selection magnets according to the invention makes it also possible to compensate dimensional changes resulting due to the unavoidable heating up of the machine during its operation in the range of the functionally important and adjusted needle selection locations. For this purpose, the magnet holders which according to the invention are constructed in the form of elongated bars fastened to the lower side of the common support ring by means of a tilt adjusting plate and by radial position adjusting screws. The inner end of the holder projecting into the recess in the needle cylinder is made of a magnetically non-conductive material upon which the selection magnet is seated. The selection magnet has pole pieces of soft iron which are directed radially outwardly toward the path of movement of the selecting jacks. The thermal expansion of the holding bar which is secured to the support ring is directed radially inwardly whereas the thermal expansion of the pole pieces of the soft iron is directed in opposite direction that means radially outwardly and consequently practically neutralizes the thermal expansion of the holder.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a radial section of a cutaway part of the needle cylinder, the cam races with supporting parts thereof on a circular knitting machine in the area of a needle selection point;
FIG. 2 is a front view in the direction of arrow II of a sectional plane of the machine of FIG. 1 showing on an enlarged scale the cam components of two adjacent systems of the machine each having its own needle selection point; FIG. 2a shows a needle in conjunction with a selecting jack;
FIG. 3 shows on an enlarged scale the detail III in FIG. 2;
FIG. 4 is a plan view a jack lifting cam of FIG. 3 when viewed in the direction of arrow IV;
FIG. 4A shows a partial view of the selecting jack;
FIGS. 5 through 8 show respectively on an enlarged scale positions of a selecting jack of a system pertaining to a needle selection point at circumferential positions V through VIII indicated in FIG. 3; and
FIG. 9 is a schematic side view of a selecting electromagnet together with its holder, shown on an enlarged scale.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates in a radial section the part of a circular knitting machine which includes a needle cylinder 10 bolted to a cylinder support gearing 11 which on its circumference is provided with outer toothed drive gear 12. A stationary cam race support plate 14 is bolted to machine frame 13 and is provided on its upper surface with a plurality of radially directed and uniformly distributed ribs 16 upon which a common support ring 15 is mounted. A jack cam race 17 which includes all cam components for each of the systems of the knitting machine is fastened on the support ring 15 and a needle cam race 18 is fastened on top of the underlying jack cam race 17. In this embodiment, the cam races 17 and 18 can be individually disassembled and removed by releasing the fastening screws 19 and 20. In a modification, both races can be integrated in a single construction unit.
The needle cylinder 10 is provided on its circumference with a plurality of axially directed slots in which webs 23 are inserted to guide needles 21 and the corresponding selecting jacks 22 which act from below on the ends of the needles. A needle in conjunction with a selecting jack is illustrated on an enlarged scale on FIG. 2. The guiding slots of the needle cylinder terminate at the level of the support ring 15 and below this level a circumferential recess 24 is formed in the lower cylinder portion which communicates with free spaces between the radially directed ribs 16 on the supporting plate 14. Selecting magnets 25 are inserted through the spacings between the ribs into the annular recess 24 and their location coincides with the selection points of respective systems of the knitting machine. The inner wall of the recess 24 is provided with an annular jacket 26 of magnetically non-conducting material which separates the magnets 25 from the needle cylinder 10 and its gear ring 11 and prevents a magnetic short circuit of the magnetic field through the needle cylinder. Each selecting magnet 25 is arranged on an end portion of a bar shaped holder 27 which is fastened via an adjustment plate 28 to the lower side of the stationary support ring 15 and adjusted in its radial position and its tilted position relative to the adjustment plate 28 by setting screws 29.1 and 29.2 and fixed in the adjusted positions by a clamping screw 30. The two setting screws 29.1 and 29.2 are supported in mounting plate 31 which is fixed to the outer wall of the support ring 15.
FIG. 2 illustrates cam components of the jack cam race 17 and needle cam race 18 pertaining to two adjacent systems of the knitting machine. In an annular groove in the jack cam race 17 is arranged a safety ring 32 for the jacks which prevents during the removal of the jack cam race 17 the selecting jacks 22 from falling out of their guiding slots in the needle cylinder 10. The superposed needle cams include a conventional sinker cam component 33 with a counter cam 34 which are jointly adjustable by means of an adjusting disk 35 illustrated in FIG. 1. The needle cam components act on a butt 21.1 of the needles 21. The selecting jack 22 which acts as a needle pusher is provided with a head butt 22.1, a lift butt 22.2, a fulcrum 22.3 and a resetting spring 35. The lower end of the stem of the selecting jack 22 is formed on its inwardly directed side with an armature surface 22.4 and the opposite stem side is formed with a straight run-on surface 22.5. This configuration of the selecting jack 22 permits simultaneously a longitudinal displacement and a tilting displacement in its guiding slot. On the front or outer side of the lift butt 22.2 a second run-on surface 22.6 is formed.
The jack cam race 17 includes lift cam components 36 for engaging the lift butt 22.2 and two circumferentially offset press cam components, namely a first press cam component 37 and a second press cam component 38 whose operation will be explained later in connection with FIGS. 3 to 8. The two press ca components 37 and 38 are situated before the selecting range A of each selecting magnet 25 when viewed in the direction of circulation of the selecting jacks, the selection regions coinciding with the selection points assigned to respective systems of the knitting machine. The additional cam components 40 and 41 serve for engaging the head butts 21.2 and for detaining the jacks in the range of their fulcrums 22.3. The cams 40 clear the way for the raising movement of the jacks 22 and guide their head butts downward into the circulation channel 40.1. The needle selection at the needle selection points takes place when the head butts are at the level of the circulation channel 40.1. The cam 41 does not act as a press cam component and a certain play is always present between the cam 41 and the stem of the selecting jack 22.
Enlarged illustrations in FIGS. 3 and 4 show a jack lifting cam 36 together with its lifting edge 36.1 for engaging the lift butt 22.2 whose various positions in the range of the first pressure cam 37 and the second pressure cam 38 are indicated for different phases of circulation of the jacks. Four of the circulation phases are indicated by reference numerals V, VI, VII and VIII. In addition, FIG. 4 also shows the lower end portion of a selecting jack 22. It will be seen from FIG. 4 that the selecting jacks 22 in the course of their circulation in the direction of arrow 39 first engage with their run-on surface 22.5 the first pressure cam component 37 which raises at relatively small angle and which moves the selecting jack 22 radially inwardly at a relatively slow rate until the jack 22 is tilted inwardly up to the position VII which is a transfer point and where the lift butt 22.2 engages with its run-on surface 22.6 the second pressure cam component 38. The position of the cam 38 is accurately adjustable by an intermediate piece 42. The pressure cam component 38 moves the selecting jack 22 from the transfer point (position VII) at a higher rate until its armature surface 22.4 abuts against a selecting magnet 25. The second pressure cam component 38 terminates in the direction of circulation with a discharge edge 38.1 which allows the spring 35 to swing back the jack 22 after its release from the magnet 25. FIG. 3 indicates also recess 43 in the lift cam 36 for receiving lift butts 22.2 of those jacks which proceed in the circumferential direction that is which don't engage the lift edge 36.1, thereby allowing an early engagement of their stems with the first pressure cam component 37.
FIG. 5 shows an entire selecting jack 22 in its position V indicated in FIGS. 3 and 4. The jack has been selected at a preceding needle selection point to engage with its lift butts 22.2 the lift edge 36.1 of cam component 36 which lifts the jack and hence the superposed needle 21 in its knitting position. The lower end portion of the jack is situated shortly before the run-on surface of the first pressure cam component 37. It will be seen from FIGS. 5 through 8 that the guiding slots or webs 23 at the level of the first pressure cam component 37 are formed with a recess 44 into which the first pressure cam 37 can enter. The lower end portion 23.1 of the guiding webs 23 overlaps the edge of the recess 24 in the needle cylinder to guide the lower end portions of the jacks passed the electromagnets 25. Inner sides 45 of the projecting portions 23.1 of the guiding webs are beveled so as to prevent interference with the pole pieces of the magnets 25.
FIG. 6 shows the selecting jack 22 in its circulation position VI in FIGS. 3 and 4. In this position, the lift butt 22.2 has exited the recess 43 in the lift cam 36 and its run-on surface 22.5 starts engaging the first pressure cam component 37.
FIG. 7 illustrates the selecting jack 22 in the position VII according to FIGS. 3 and 4. Its first run-on surface 22.5 has already raised a certain distance on the first pressure cam component 37 and accordingly, the jack has been tilted about its fulcrum 22.3 and has reached a point where the second run-o surface 22.6 on the lift butt 22.2 starts engaging the second pressure cam component 38. The peak point on the first pressure cam component 37 has been already reached and the tilting movement of the selecting jack 22 is taken over by the second pressure cam component 38 acting on the lift butt 22.2.
FIG. 8 shows the jack 22 in its position VIII of FIGS. 3 and 4. The lift butt 22.2 has reached the highest point on the second pressure cam component 38. At this maximum swing out position the armature surface 22.4 at the lower end of the jack is pressed against the corresponding selection magnet 25 whereby preferably a light overpressure is exerted by the cam so as to introduce a slight bowing or arching of the jack stem portion between the fulcrum 22.3 and the contact point of the armature surface 22.4 with the magnet, thus neutralizing manufacturing tolerances and wear. Then the jack 22 is discharged from engagement with the second pressure cam component 38 along the discharge edge 38.1 of the second pressure cam component 38 (FIG. 4) and the jack is either retained in this position by the electromagnet 25 to proceed to the next system of the machine in the circulating direction, or is released by the electromagnet and consequently the return spring 35 tilts the jack in a position in which in the following system its lift butt 22.2 is brought into engagement with lift cam 36.
FIG. 9 shows the construction of the selection magnets 25. Each selection magnet is designed in conventional manner and includes two superposed pole pieces 46 and 47 of soft iron which at one end thereof are in contact with an interposed permanent magnet 419 and anchored in a support block 48 of a magnetically non-conducting material. The opposite free ends of the pole pieces are connected to an interposed slide strip 50 of saphire having a raised slide face against which the armature surface 22.4 of the selecting jacks 22 is pressed. Each of the pole pieces 46 and 47 is provided with a releasing winding 51 or 51.1 supplied by current pulses which neutralize the pulling force of the permanent magnet and by a magnetic field pole reversal release the end portions of the selecting jacks 22. The magnetically non-conductive support block 48 is screwed to an end portion of a web or bar-shaped magnet holder 27 whose opposite end is adjustably secured to the support ring 15 as it has been described in connection with FIG. 1. Both the magnet holder 27 and the pole pieces 46, 47 have their free ends oriented in opposite radial directions. Accordingly, after heating the machine the longitudinal expansion of the magnet holders 27 occurs in the direction of arrow 53 and this expansion is neutralized by the opposite expansion movement of the soft iron pole pieces in the direction of arrow 52. As a consequence, the adjusted position of the selection magnets 25 relative to the circulation path of the selecting jacks 22 is held constant. In addition, the construction of the knitting machine according to this invention permits a readjustment of the position of the selecting magnets 25 or the exchange of individual magnets without the necessity of dismantling the supports of cams of the corresponding system.
While the invention has been illustrated and described as embodied in a specific example of a circular knitting machine, it is not intended to be limited to the details shown, since various modifications and structural changes ma be made 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. | In a multiple system circular knitting machine having an electromagnetic needle selection, the needle and jack cam races are supported on a stationary support ring which rests on a plurality of radially directed and mutually spaced ribs. To improve operational reliability and maintenance of needle selection devices, each selection electromagnet is mounted at an end portion of an elongated holder and is situated in a circumferential recess in the needle cylinder opposite end portions of respective selecting jacks. The magnet holders are adjustably secured to the lower surface of the support ring. The needle selecting cams include a pair of circumferentially staggered and axially superposed pressing cams of which the leading lower pressing cam first engages the lower end portion of the selecting jack and moves the same radially inwardly to a point where the upper pressing cam takes over and presses an armature surface of the end portion of the jack against an electromagnet. In this manner, the negative effect of wear of selecting cams is neutralized. | 3 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates in general to the construction of sewing machines and, in particular, to a new and useful sewing device for producing form seams which includes a guide device for the needle which is provided with a force-away surface which is movable in a direction opposite to the movement of the workpiece in respect to the needle.
DESCRIPTION OF THE PRIOR ART
The present invention relates to a sewing device for producing form seams, including a guide mechanism for guiding the workpiece along a path corresponding to the desired configuration of the seam and relative to the needle of a sewing machine which cooperates with a rotary hook. The guide mechanism comprises a vertically movable support by which the workpiece is supported in the piercing area of the needle and the support is provided with a stitch hole for the needle.
The term "form seams" refers to seams which may run in different directions, for example, seams for sewing pockets on pieces of clothing, sewing collars and cuffs, ornamental seams on top parts of shoes, etc.
In a sewing device of this kind, for example, as seen from German Offenlegungsschrift No. 2,251,929, it is known to provide a workpiece support which is similar to the feed dog support and is provided with a cylindrical extension corresponding to the width of the slot for the needle passage in the workpiece holder. Vertical oscillating motions are imparted to this holding element, in order to provide an exact support for the workpiece held in the workpiece holder of the guide mechanism during the period of time in which the needle is engaged in the material, and thus to prevent the so-called wave formation caused by the attack of the needle as it penetrates into the workpiece in the abscence of a support.
Since during the production of form seams, the direction of displacement of the workpiece changes several times in the course of one sewing operation, and since in such sewing devices it was necessary, for various reasons, to dispense with an intermittent displacement of the workpiece, the result of the continuous displacement and change of direction of the sewn material, is that the needle, particularly while working with densely woven firm cloth, is bent or deflected by the material in different directions. In order to avoid defective stitches, the needle and the point of the rotary hook, in their loop-engaging position, must be spaced from each other as little as possible without coming into contact with each other since this would damage the point of the hook and make the hook useless in a very short time. However, this is exactly what occurs if the workpiece is displaced in the direction of the rotary hook and, at the same time, the needle is bent toward the hook.
SUMMARY OF THE INVENTION
The purpose of the present invention is to prevent damaging of the rotary hook. More particularly, the invention is directed to a design which prevents the needle from moving into the circular path of the hook point during the displacement of the workpiece in the direction of the rotary hook.
In accordance with the invention, the limiting surface of the stitch hole is associated with the needle as a guide or force-away surface and is made displaceable, in tune with the stitch formation, in an opposite direction relative to the motion of the workpiece toward the rotary hook.
The exchange of the workpiece support and the timing of the displacement of the needle guide surface are facilitated by designing the workpiece support as an anvil plate which is secured to a supporting bar of the sewing machine, and by providing adjustment means for adjusting the magnitude of the displacement which is connected to the bar.
Accordingly, it is an object of the invention to provide a sewing device for producing form seams which are usable with a sewing machine having a needle which reciprocates in respect to a cooperating rotary hook and which also includes a guide mechanism for guiding the workpiece along a path corresponding to the configuration of the form seam in respect to the needle, and which comprises a workpiece support member having a stitch hole for the passage of a needle and which includes a raised surface forming a force-away surface bounding the stitch hole and wherein the workpiece support member is mounted between the needle and the rotary hook by mounting means which are connected to actuating means so as to move the force-away surface in a direction away from the movement of the workpiece during the reciprocation of the needle.
A further object of the invention is to provide a sewing device for producing form seams which is simple in design, rugged in construction and economical to manufacture.
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 uses, reference should be had to the accompanying drawing and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the Drawing:
FIG. 1 is a partial top plan view of a sewing machine with a workpiece clamping mechanism usable with the sewing device constructed in accordance with the invention;
FIG. 2 is an enlarged perspective view of a portion of the sewing machine in a simplified representation which includes a workpiece clamping mechanism and guide mechanism associated therewith; and
FIG. 3 is an enlarged partial sectional view of a workpiece support constructed in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawing in particular, the invention embodied therein, comprises a sewing device which is used on a flat-bed, single-needle sewing machine 1 of conventional construction, which is mounted on a frame, not shown, and driven by a stop motor, also not shown, in a well known manner. Sewing machine 1 is associated with a guide mechanism 2 (FIG. 1) for a workpiece clamping mechanism 3. The free end of a main shaft 4 of the sewing machine, (FIG. 2), carries a main shaft crank 5 which is connected, through a link 6 and an intermediate member 7, to a needle bar 9 carrying a thread guiding needle 8 which is guided for up and down motion in a frame 10. Thread guiding needle 8 cooperates with a lock stitch rotary hook 11 of well-known design having a hook point 12. Rotary hook 11 is secured to a hook shaft 13 rotating at a speed double that of the main shaft 4. To engage hook point 12 into the needle thread loop, needle 8 plunges into a stitch hole 14 of a workpiece support 15 which is designed as a plate and provided with an anvil-like cylindrical extension 16. The loop-engaging position of the stitch-forming parts is shown in FIG. 3.
Workpiece support 15 is secured to a supporting bar 17 of sewing machine 1, the free end 18 of which is forked and engages over an eccentric 19 which is secured to a shaft 20. The free end of supporting bar 17 is hinged, by means of a pin 23, to a crank 22 which is secured to an oscillating shaft 21. With shaft 20 in rotary motion, an oscillatory motion in a vertical plane, about pin 23, is imparted by eccentric 19 to supporting bar 17 and workpiece support 15.
Oscillating shaft 21 is hinged, through a lever 24, a pin 25 and a link 26 to a mechanism for adjusting the magnitude of the horizontal motion in order to also impart a horizontally reciprocating motion to supporting arm 17. On its other end, link 26 is engaged on a pin 27 to which a further link 28 is secured and the free end of which is acted upon by an eccentric bar 29 which engages over a drive eccentric 31 secured to a shaft 30. Link 28 is connected to lever 33, which is secured to an adjusting shaft 36, by means of a pin 32. Shaft 36 is mounted for rotation in a bearing bracket 34 of the fabric supporting plate of sewing machine 1 and can be fixed by means of screws 35. A hand lever 37 is secured to the free end of adjusting shaft 36 by means of a screw 38. Links 26 and 28 have effective lengths which are equal to each other.
As seen in FIG. 1, the workpiece clamping mechanism 3 which receives the workpieces (hind part of trousers W and pocket cut T), comprises a support plate 39 which is displaceable on the fabric supporting plate 15 of sewing machine 1. A clamping plate 40 is pivotally mounted on the supporting plate 39. Both supporting plate 39 and clamping plate 40 are provided with a slot 41, corresponding to the configuration of the seam to be produced. In the example shown, a substantially U-shaped pocket seam N defines a passageway for needle 8. It is to be noted that the diameter of the cylindrical extension 16 of workpiece support 15 is slightly smaller than the width of slot 41 so that, in the piercing area of needle 8, extension 16 can support the workpiece.
Supporting plate 39 of the workpiece clamping mechanism 3 is connected to two links 42, 43 of a parallelogram guide of guide mechanism 2. Link 42 is pivoted to a fixed pin 44 and carries a guide roller 45 projecting into a guide groove 47 which is provided in the underside of a control disc 46 and which, for clarity, is shown as a curved endless dash-dotted line in FIG. 1. Second link 43 is hinged to an intermediate member 48 which is also pivoted to pin 44. Intermediate member 48 carries a guide roller 49 which projects into a guide groove 50 which is provided in the upper side of control disc 46 and is shown curved endless dash-double dot line in FIG. 1. By the rotary motion of control disc 46 about a fixed pivot 51 through 360° divided into portions of travel indicated by F, a 1 - g 1 and R, produced by a separate motor (not shown), the two links 42 and 43 are pivoted about pin 44 and impart a corresponding motion composed of two components and following the pattern of the seam to be produced to workpiece clamping mechanism 3.
As soon as workpieces W and T are clamped in mechanism 3 with the control disc 46 in rotary motion about its pivot 51 through the portion of travel indicated by F in the direction of arrow D, workpiece clamping mechanism 3 is first displaced from its feed position, according to FIG. 1, to the stitch-forming area in a manner such that point I, at which seam N starts, becomes vertically aligned with the needle, whereupon, sewing machine 1 is started. Due to the guidance of the rollers 45 and 49 in guide grooves 47 and 50 respectively, the workpiece is first displaced in the direction of arrow a, for securing the seam while the disc 46 is rotated through portion a 1 , and then the clamp 3 is continuously moved, while changing its direction several times, as indicated by arrows b to g of FIG. 1, up to the finish end at II, following a path corresponding to the seam N which has been provided while the disc 46 is rotated through the portions of travel indicated by b 1 - g 1 . At the end of the seam N at II, the sewing machine is stopped, the thread is cut by a known thread cutter and the disc 46 is rotated to its initial or starting position through the portion of travel indicated by R, moving the clamp 3 to its feed position, shown in FIG. 1.
During the run of sewing machine 1, due to eccentric 19, vertical oscillatory motions about pin 23 are imparted to workpiece support 15. These motions are coordinated with the up and down movements of needle 8 in a manner such that the anvil-like extension 16 projecting into slot 41 of plates 39, 40 supports the portion of the workpiece which is presented above the stitch hole 14 during the penetration of needle 8.
Due to the continuous motion of the workpiece during the displacement of the workpiece in the direction of arrows c, d, and e, needle 8 is pressed by the fabric in the direction of rotary hook 11. Horizontal motions are also imparted to the workpiece support 15 in order to displace the limiting surface of stitch hole 14 which serves as a guide or forceaway surface for needle 8. The surface 16 bounding stitch hole 14 is moved in a direction opposite to the motion of the workpiece toward the rotary hook 11 and thus prevents the needle from moving into the circular path of, and colliding with, the hook point 12. The horizontal motions of workpiece support 15 are produced so that through eccentric bar 29 and pin 27, drive eccentric 31 imparts oscillatory motions about pins 25 and 32 to links 26 and 28. These motions are pure rotary motions as long as pins 25 and 32 are aligned. If, upon loosening screws 35, the angular position of adjusting shaft 36 is changed, this shaft, while turning, takes along lever 33 and thus changes the position of pin 32, serving as an axis of rotation for link 28, relative to pin 25. Therefore, while pin 27 is swung out by eccentric bar 29, it executes a pure rotary motion about pin 32, while link 26, aside from this rotary motion, in addition executes a relative motion about shaft 21. This relative motion is transmitted by lever 24 as an oscillatory motion to crank 22 which imparts horizontal motions to workpiece support 15 through supporting bar 17. Adjusting shaft 36 is secured in its adjusted position by tightening screws 35.
It is evident that due to the composed movement of workpiece support 15, the workpiece clamped between plates 39 and 40 is supported during the penetration of needle 8 by the cylindrical extension 16 in the area of penetration of the needle, and that the needle is forced away by the limiting surface of stitch hole 14 in the opposite direction relative to the workpiece displacement (arrow d) which is directed toward rotary hook 11.
The movements of the workpiece clamping mechanism 3 in the directions designated a to g, in relation to guide rollers 45, 49 and to control disk 46, are such that with a complete revolution of control disk 46, all the partial movements of mechanism 3 in the directions indicated a to g in FIG. 1 are produced, which movements are rectilinear. For transmitting these straight-lined partial movements from guide grooves 47, 50 of control disk 46 through guide rollers 45, 49 to mechanism 3, always both guide grooves 47, 40 must participate in the control. Thus, for producing the partial movements a, b, f, and g, horizontal in FIG. 1, groove 50 will produce, through roller 49, the main component of the motion, but groove 47 will add, through roller 45, an equalizing motion, since, due to the mounting of the parallelogram linkage 2 supporting mechanism 3 on pivot pin 44, all rectilinear movements are produced by two components of the rotary motion about pin 44. As to partial movement d, on the contrary, the main motion component is produced by groove 47 through roller 45, while the equalizing motion for the rotation about pin 44 is furnished by groove 50 through roller 49.
In the obliquely directed partial movements c and e, both grooves 47 and 50 participate approximately to the same extent.
As shown in FIG. 1, groove 47, in which roller 45 is guided, is indicated as a dash-dotted line, and groove 50, in which roller 49 is guided, is indicated by dash-double dotted line following the actual shape of the groove necessary for producing the movements of mechanism 3. Further, F indicates the angular portion for moving mechanism 3 from its feed position into its sewing-start position. a 1 to g 1 indicate the corresponding annular portions for producing the partial movements a to g, and R indicates the angular portion for returning mechanism 3 into its initial position upon finishing the seam.
While producing form seams, the workpiece is moved continuously, even though the direction of the movement is varied several times. This means that the motion of the fabric or the clamping mechanism is not interrupted during the periods in which the needle is engaged in the fabric. Thereby, if thicker and firmly woven material is sewn, the needle is temporarily deflected in the direction of the fabric motion. A deflection of the needle in directions, straight or obliquely, away from the circular path of the hook point has no disadvantageous consequences. If, however, the needle is deflected by the motion of the fabric in a straight or oblique direction toward the path of the hook point, thus in the direction of arrows c, d, and e of FIG. 1, there is a risk that, in spite of the provisions of the non-designated recess in needle 8, the needle will collide with the hook point and cause damage to the quite expensive rotary hook. The purpose of the boundary surface of the stitch hole is to counteract this deflection of the needle in the direction of the path of motion of the hook point, caused by the moving fabric. The effect is that the needle is not deflected from its normal position and is rather backed by the mentioned boundary surface of the stitch hole or displaced in a direction opposite to the fabric motion, in a manner such that the needle keeps its normal position during a displacement of the fabric toward the hook point or is pushed into its normal position, as shown in FIG. 3.
A force-away motion of some tenths of a millimeter is quite satisfactory for effectively preventing a deflection or bending of the needle by the workpiece and for securely maintaining the needle out of the circular path of the hook point during the displacement of the workpiece toward the hook.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A sewing device for producing form seams is usable with a sewing machine having a needle which reiprocates in respect to a cooperating rotary hook. The sewing machine also includes a guide mechanism for guiding a workpiece along a path corresponding to the configuration of the form seam in respect to the needle. The device includes a workpiece support member having a stitch hole for the passage of the needle and a force-away surface bounding the stitch hole. The device includes a plate which is mounted so that the force-away surface is disposed between the needle and the rotary hook and it is mounted for vertical movement and horizontal oscillatory movement. The actuating means for the device causes a movement of the force-away surface in timed relationship to the reciprocation of the needle and in accordance with the movement of the workpiece in a direction opposite to the movement of the workpiece with respect to the needle and the rotary hook. | 3 |
BACKGROUND AND SUMMARY OF THE INVENTION
There exists a need to rapidly and inexpensively drill holes through earth in vertical, slanted and horizontal positions. Oil wells are now drilled vertically or nearly so, usually with a slow rotary drill. Water wells are drilled vertically with either a hammer type impact drill or a rotary drill, usually in a vertical position. Usually ditching machines are used to dig the ditches, for laying pipe, burying cables and installing fiber optic cables. This invention is for drilling an oil well and uses an expendable electromagnetically accelerated drilling projectile or drill head to drill a hole by hyper velocity impact. The nearest prior art we find is my pending patent application for a High Speed Electromagnetically Accelerated Earth Drill, Ser. No. 07/491,276, filed Mar. 9, 1990, now U.S. Pat No. 4,997,047. However, this invention differs significantly in necessary mechanical structure.
We visualize that drilling an oil well would be started in the usual way and some twelve hundred feet of twenty-four inch diameter casing would be set. The electromagnetically accelerated impact oil well drilling equipment or drilling gun would then be hoisted into place in the derrick and aligned accurately to shoot an ice filled thin plastic projectile down through the casing at hyper velocity. In the approximately seventy-five foot long drilling gun the missile should attain a velocity of over 15,000 feet/second and our calculations indicate that this would penetrate over 50 to 100 feet of concrete, shale, soft rock or normally compacted sand. A special well effluent diverter is activated in a nanosecond after the drilling missile enters the casing. This is necessary to divert well effluent away from the interior of the drilling gun.
SUMMARY OF THE INVENTION
The equipment for drilling vertical holes in this invention encompasses an external housing to contain means to freeze water in an expendable drill head that has metallic induction rings on the drillhead. In use, the expendable drill head is air propelled into the firing chamber which is aligned with central cylindrical openings of multiple conductive wire coils called accelerator coils and separating spacers for the coils in an electromagnetic accelerator, an integral part of the drilling gun. Circuitry of each of the multiple conductive wire coils produces an alternating electromagnetic force or ringing circuit when a tip end of the expendable drill head interrupts a photo-electric cell circuit that acts to open a nanosecond switch in a charging circuit for each coil. The circuit to each coil includes a variable or fixed capacitor across the inlet leads. The frequency of the alternating electromagnetic force produced is controlled by the capacity of the capacitor while strength of the electromotive force is controlled by the charging voltage and construction of the coil. In a preferred embodiment a variable capacitor with multiple plates allows easy variation of capacitor capacity.
The coils may be relatively slowly charged using batteries or homopolar generators. Nanosecond switches are used to open the circuit to cause an alternating electromotive force quite generally called a ringing circuit and must be properly timed with arrival of the projectile or drill head a it is accelerated through the magnetic accelerator.
Acceleration is determined by strength of the electromotive forces generated in the accelerator coils and strength of the magnetic field on the expendable drill head and timing to have maximum interaction. Direct current charged coils induce current in aluminum or copper rings or other type conductive rings around the expendable drill head and opening the circuit of each accelerator coil allows production of high strength alternately aligned magnetic poles for the short duration time needed for acceleration through the electromagnetic accelerator to increase the speed after the drill head has been propelled into the accelerator by an air propellant chamber. Expected residence time after the drill head is air propelled into the unit should be less than two hundredths of a second.
The accelerator is prestressed to avoid separation of the coils during use and in one preferred embodiment is mounted between heavy rails with shock absorbers to minimize recoil and return the accelerator to position for continued use. In another embodiment, the accelerator is mounted between reinforced concrete bases of sufficient weight to absorb recoil. Adjustable mounting pads may be automatically adjusted to maintain the unit in proper alignment as expendable drill heads are serially fed into the accelerator unit.
In one preferred embodiment, the accelerator with double concrete side support is held upright by the drilling block in the usual oil field drilling rig in the same way as drill pipe is supported. The base of the accelerator may have interconnecting tapered dowels or tapered grooves or other alignment interlocking shapes in the floor of the drilling rig to assure proper alignment. The large primary oil well casing installed is equipped with a diverter valve that is activated in less than a nanosecond after each projectile is fired down through the primary casing. This diverter prevents effluent from the well from being thrown back into the drilling gun.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 1A show an upright view of the assembly.
FIGS. 2-2C show the accelerator with an expendable drill head in firing position with electronic circuitry.
FIG. 3 shows a top view of the induction coil as it is formed in plastic.
FIG. 4 shows a baffled cooling water path that is formed on top of each induction coil.
FIGS. 5-5C show an exploded view of a preferred embodiment wherein one accelerator coil unit is formed with three internal inductance coils electrically connected in parallel to act as one unit and with cooling water flow over each of the three inductance coils.
DESCRIPTION OF PREFERRED EMBODIMENT
The electromagnetically accelerated impact oil well drill of this invention uses hardware best described from the drawings. The drawings refer to preferred embodiments but we will also describe some variations useable in other embodiments.
In FIG. 1 we show a section view indicating major hardware and arrangement. The unit 1 is meant to be moved using power means such as a crane or winch truck and lifting lugs 4 attached to steel head reinforcement 7 which is bolted integrally to concrete rails 2. In use, the weight of the unit is held by drilling rig lifting block through lifting cables 21 and the base is properly positioned by positioning guide 5 in drilling rig base 20. Proper alignment is critical and the unit is equipped with four adjustable alignment jacks 11 to allow proper lateral adjustment. A surveyor transit would be used for measurement to ascertain proper positioning. The base 20 may be weighted with concrete. In a preferred embodiment, concrete mounting rails 2 absorb reactive forces. In other embodiments, the recoil may be handled in several ways such as by bolting to a very heavy base, spring loading, and hydraulic shock absorbers.
An external storage compartment holds expendable drill heads 8 with means to cool and freeze water in the drill heads. The drill heads 8 with charge rings 9 may be hand fed through compressed air chamber 6 to rest on double spring loaded holder 13. When air is fed into chamber 16 and pressure builds up to about 500 psi to compress spring 17, the poppet valve opens and the ice filled drill head 8 is propelled into the accelerator barrel 47. An explosive charge could also be used for this initial acceleration.
Drill head 8 is electromagnetically accelerated throughout the length of acceleration barrel 47 and is aligned to enter casing 25. As the tip of the drill head 8 breaks a light beam from light source 31 to photochemical cell 32 conventional electrical circuitry activates diverter valve flapper drive coil to position diverter valve flapper 27 to cause effluent from the casing 25 to blowback through blowout preventer 26 and out diverter exit line 29.
Multiple clamps 3 clamp the coil assembly between rails 2. Depending upon size of the unit two or four rails 2 may be used. Alignment jacks 11 near the top of the unit are used to adjust the unit to perfect vertical position. Any of several methods may be used for the checking to make certain the unit is exactly vertical and properly aligned with casing 25.
In FIG. 2 we show one of the simple versions of the ice filled drill head. Many other type drill heads of non-conducting crushable material could be visualized. The drill heads have two or more, usually four conductive metal rings 9 and are filled with water which is held frozen by refrigeration coils 12. Induction coils 10 induce current in rings 9 when a switch 42 is closed. Charge rings 9 are preferably made of aluminum. Switch 42 may be interlocked to open when pressure in chamber 6, FIG. 1, is just sufficient to open spring holder 13. When the expendable drill head 8 leaves the mounting position, flow of current in the conductive rings 9 creates alternate N-S magnetic fields. Tip 14 is of a length that properly times opening of nanosecond switch 53 by activating photoelectrical cell 45 by interference of tip 14 with a light path from source 46 to the photoelectric cell 45.
Calculations indicate that with less than thirty electromagnetic accelerator coils 49, using four conductive rings 9 around a cylindrical expendable ice filled drill head 8 that, when capacitors 51 are properly sized to vary the frequency of the current to make maximum use of stored electrical energy, velocities of 5 miles per second or more may be reached. Maximum use of electrical energy occurs when N-S, S-N, N-S, etc., magnetic force interaction is such that the first pulse in coils 49 acts to "push" the first conductive ring 9 while pulling the second conductive ring 9 and the second pulse acts to "push" the second conductive ring 9 while pulling the third ring 9 and the third pulse acts to "push" the third ring 9, etc. As the expendable drill head 8 increases in velocity the second ring comes into the force field generated by the electromagnetic accelerator coils more rapidly. Therefore, for maximum efficiency the frequency of the generated current must increase as the velocity of the expendable drillhead increases. This frequency may be increased by reducing the capacitance of the capacitor 51. In this manner, nearly constant acceleration may be achieved. Calculations would indicate some small efficiency increase by varying the spacing of the second, third and fourth conductive rings on the expendable drill head.
With electrical circuit as shown in FIG. 2 the rings 9 will have alternate N-S, S-N, N-S magnetic force field. The induced electromagnetic force in rings 9 exists for sufficient time for acceleration to speeds in the range of five miles per second.
Also shown in FIG. 2, accelerator coils 49, also referred to as electromagnetic propellant rings, are made of multiple turns of insulated conductive wire such as copper, wound in a coil with a square cross section and potted in a hard resin. In a preferred embodiment, the conductive wire is ribbon shaped. Spacer rings 48 are made of a non-conducting material in a shape similar to the accelerator coils. We've indicated a light source 46 and photoelectrical cells 45 in the spacer rings 48, with one extra at the end of the accelerator. Spacer rings 48 and coils 49 are arranged in a gun barrel-like configuration. Leads from accelerator coils 49 go through a nanosecond switch 53 such as a Power MOS-FET switch to a D.C. source 52. A capacitor 51 is across the leads going to the power source. The capacitor may be a variable capacitor with multiple plates with multiple take off leads to allow in-service choice of sufficient plates to give desired microfared capacity. Differing size capacitors 51 vary the frequency of the "ringing" type circuit caused when switch 53 is opened after coils 49 are charged by batteries 51. Note that other types of D.C. source such as homopolar generators or an A.C. rectifier could replace the batteries. As shown in FIG. 3, the coils 49 and spacers 48 are square and four large boIts 43, FIG. 2, through holes 64 are used to pre-load the coils and spacers to form the barrel.
FIG. 3 shows a top view as an accelerator coil 49 is formed. An insulated copper ribbon 60 is wound in a coil with an exit lead 62 creased to lay flat on top of the coil 60 and a flat inlet lead 63 attaching to an inlet end of coil 60. A simple form, which may be of any of several plastics, and is about 3/8 of an inch higher than the thickness of the coil 60, is placed to form an exterior baffle with other cylindrical forms of the same height placed to form holes 64 and a hard plastic such as an epoxy poured to be level with the top edge of coil 60. Now, when the coil 60 is charged and discharged rapidly enough, heat is generated and FIG. 4 shows the cooling face 76 formed on top of coil 60 in FIG. 3 as follows: the edge of coil 60 is coated with an acrylic glue and flat ceramic strips 73 approximately 1/2 inch de and 3/8 inch thick are laid as shown between an inner 0 ring 71 and outer O ring 72; a baffle 70 separates a plastic water inlet line 74 and exit line 75. A hard plastic, such as epoxy, is poured exterior of O ring 72 to be just slightly below the top of O ring 72 to form face 76. Face 76 is then coated with acrylic glue and three segments formed as described are glued together to form one accelerator coil, in one preferred embodiment. In other embodiments with electrical connections as shown in FIG. 2 one accelerator coil is made with a single internal insulated metal coil which may be either of an insulated metal ribbon or insulated wire.
In FIG. 5 we've shown a three part accelerator coil 65 as described, which is a preferred embodiment, indicating that the ringing circuit in each coil is formed simultaneously since MOS-FET nanosecond switches 53 are connected in parallel with a photoelectric sensor 45 in spacer 48 activating the switches 53. A D.C. source 67 which may be a battery charges the internal copper coils 60, FIG. 3. The three units are glued together thereby forming three internal coils that are wired to act simultaneously and have cooling water on each side, with inlet water 72 traveling between baffles 73 and out to exit header through exit line 75. An increase in effectiveness of the accelerator coils 65 may be realized by chilling the cooling water to the coils or by cooling using a refrigerant.
Since many mechanical and electrical details may be changed without altering the function, we do not wish to be limited to exact details, but only as to the spirit and purpose as outlined in these claims and specifications. | The electromagnetically accelerated impact oil well drill uses magnetic interaction of a ringing circuit formed in each of multiple accelerating coils with the electromagnetic field of charge rings around an expendable ice filled plastic drill head to accelerate the drillhead to hypervelocity with the drill head properly aligned to shoot down through an upper installed oil well casing. The oil well casing being fitted with a rapidly operating diverter valve to deflect effluent from the casing from blowing back into the electromagnetically accelerated impact drill. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and hereby claims priority to PCT Application No. PCT/DE00/04535 filed on Dec. 19, 2000 and German Application No. 199 615 16.0 filed on Dec. 20, 1999, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The invention relates to a method for controlling a handover in a radio communications system.
A mobile radio communications system typically comprises a multiplicity of transceiver stations or base stations which exchange radio signals with mobile terminals which are located within the range of these stations, and at least one administration unit which switches user data between mobile terminals which are located within the range of different base stations, or between a mobile terminal and a fixed network.
A “W-CDMA” mobile radio communications system such as the TDD mode of the forthcoming third-generation UMTS mobile radio system (Universal Mobile Telecommunication System) provides the facility for a mobile terminal to communicate at a given time with a subset of these transceiver stations by receiving user data associated with a single call connection on different channels of a plurality of these stations, and, conversely, user data transmitted by the terminal are also received by this plurality of stations. This subset is also designated as the active set.
The purpose of this intrinsically redundant transmission is the avoidance of transmission gaps if the mobile terminal moves out of range of a station with which it is communicating; if it is communicating with one single station only, the radio link is interrupted when it moves outside its range and the user data transmission from and to the terminal cannot continue until a different station is allocated to said terminal, the user data which are to be transmitted to the terminal are switched to this station, and the terminal and the new station can be synchronized with one another. On the other hand, in the event of simultaneous communication with a plurality of stations, failure of the radio link between the mobile terminal and one of the stations does not yet result in interruption of the transmission, since said transmission continues to run unchanged via the other stations, while an alternative station is defined for the failed station and communication is set up with said alternative station. This type of station changeover with continuation of the communication with one or more other stations is referred to as “soft” handover.
However, simultaneous communication with a plurality of stations entails a substantial loading of the switching and transmission capacity of the radio communications system. If each active terminal occupies transmission channels of a plurality of stations, the number of mobile radio subscribers which can be served simultaneously with a given network infrastructure is of course considerably smaller than if each terminal uses only one channel of a station. Similarly, in the mobile terminal, the need to process receive signals from a plurality of channels can result in increased power consumption and therefore in a reduction of the network-independent usage time of a terminal of this type. A compromise between transmission reliability and transmission capacity therefore needs to be found, which is usually such that, for a radio communications system of this type, the maximum number of stations which may belong to the active set is defined as a small value of e.g. 2 or 3.
The stations which belong to the active set are identified using regularly repeated evaluations of the quality of transmission between the mobile terminal and the stations which are able to communicate with it. For this purpose, the mobile terminal measures the quality of radio signals which it receives from these stations. Stations which do not belong to the active set, but whose transmission quality, from one evaluation to the next, has become higher than that of a station of the active set, are reported to an administration unit which adds them to the active set and in return excludes the poorer station.
Simulation experiments have shown that, in a system of this type, it may often be the case that the quality of transmission between the mobile terminal and all stations of the active set becomes so poor between two transmission quality evaluations that the entire active set must be replaced at once. This results in a transmission gap. Such a situation may arise in particular if the mobile terminal is moving in an urban environment, where roads bordered by buildings can transport a radio signal over long distances in a longitudinal direction, but will screen it in a transverse direction, so that a terminal located on a road of this type may have an active set in which only relatively far-distant stations are located. As soon as the terminal moves into a transverse road, transmission from and to all the stations may be virtually simultaneously interrupted.
From WO99/04593, a method is known for the selection of base stations for communication with a mobile station, in which the mobile station receives signals from a plurality of base stations, referred to as the “candidate set”, identifies a relevant receive strength and compares it with a first threshold value. Base stations whose receive strengths lie above the threshold value are reported to a base station controller as suitable for inclusion in the active set of base stations. The mobile station identifies the need for changes to the current active set through measurements of the energies of pilot signals of the base stations of the active set and the candidate set, and through dynamic adaptation of the threshold values.
One potential object for the invention is to provide a method for controlling a soft handover with which high immunity of the transmission to interruptions is achieved without loading the switching and transmission capacity due to substantially increased redundancy, and without resulting in a significant increase in the power requirement of the terminal.
SUMMARY OF THE INVENTION
While the mobile terminal is located in a designated typical normal operating condition, a check is preferably carried out periodically to ascertain whether there is at least one station among the transceiver stations which do not belong to the active set which is suitable as an additional station in the event that a handover must be carried out. The check may be carried out at a frequency of at least 1 Hz. A station of this type, referred to below as a candidate station, is added to the active set if a need for a handover is established. The periodic repetition of the check is required in order to ensure that the candidate station is still suitable if this need actually arises. Communication between the candidate station and the mobile terminal can then be set up immediately without losing valuable time in identifying a suitable candidate station.
According to a first alternative, in order to identify the candidate stations, the transmission quality of a radio signal originating from the mobile terminal can be measured at the transceiver stations which do not belong to the active set, and the stations which receive the best signal are selected as the candidate stations. In such a case, it is appropriate for the measured transmission qualities to be transferred from the stations to an administration unit of the radio communications system, which selects the candidate stations on the basis of the transferred transmission qualities.
According to a second alternative, the mobile terminal can measure the transmission quality of radio signals which originate from transceiver stations which do not belong to the active set, and one or more transceiver stations which reveal the highest transmission quality are selected as candidate stations. The selection can be carried out by the mobile terminal and reported to an administration unit of the radio communications system, or the mobile terminal transmits the measurement results to the administration unit, which selects the candidate stations.
This second alternative can usually be implemented at lower cost than the first. Since an administration unit is normally responsible for a large number of terminals, substantial computing outlay may be required in the administration unit in the first alternative in order to allocate the transmission qualities delivered by the stations for each individual mobile terminal to the individual terminals, to compare them and to select suitable candidates. If, however, according to the second alternative, the transmission qualities are measured by the mobile terminal, the expensive allocation is not required, thereby relieving the load on the administration unit.
The need for a handover is preferably identified if the qualities of transmission between the mobile terminal and the transceiver stations of the active set fall below a limit value. The transmission quality considered here may be that of the uplink transmission (from the mobile terminal to the station) and/or that of the downlink transmission (from the station to the mobile terminal).
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 shows a block diagram of a radio communications system, in particular a mobile radio system,
FIG. 2 shows the results of an evaluation of the quality of transmission between a mobile terminal and the individual stations of a radio communications system;
FIGS. 3 a to 3 c show a sequence of evaluation results at different times during and after a handover procedure;
FIGS. 4 and 5 in each case show evaluation results at the beginning of handover procedures.
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 mobile radio system shown in FIG. 1 as an example of a radio communications system comprises a multiplicity of mobile switching centers MSC, which are networked with one another or which set up access to a fixed network PSTN. Furthermore, these mobile switching centers MSC are in each case connected to at least one terminal RNC for allocation of radio resources, previously referred to as the administration unit. Each of these terminals RNC in turn enables a connection to at least one base station BS. A base station BS of this type can set up a connection via a radio interface to subscriber stations, e.g. mobile stations MS or other mobile and stationary terminals. At least one radio cell is formed by each base station BS. An operation and maintenance center OMC implements monitoring and maintenance functions for the mobile radio system or for parts thereof.
The functionality of this structure can be transferred to other radio communications systems. Examples of such systems are the GSM and FDD mode of the UMTS mobile radio system, or mobile radio systems based on the American standard IS-95 with CDMA subscriber separation. One aspect of the invention relates in particular to W-CDMA systems, but is generally applicable to any radio communications system which offers the facility for a plurality of radio links to an individual terminal to be maintained, on which a plurality of stations in each case transmit the same user data to the terminal or user data transmitted by the terminal are received and processed by a plurality of stations.
In order to explain different designs of the method, a radio communications system with a plurality of base stations BS 1 , BS 2 , . . . and an administration unit is considered. A mobile terminal MS moves in the geographical area covered by the base stations, at different distances from the individual base stations and with different transmission qualities between it and the base stations.
FIG. 2 shows in diagrammatic form the transmission qualities between the mobile terminal MS and five base stations BS 1 , BS 2 , BS 3 , BS 4 , BS 5 . The minimum transmit power p which the mobile terminal MS requires in order to transmit to the relevant base stations BS 1 . . . BS 5 while maintaining a given error quota is plotted on the vertical axis of the diagram as a measure of the transmission quality. The BS with the lowest minimum transmit power, i.e. the lowest on the diagram, is in each case regarded as the BS with the highest transmission quality.
In the diagram in FIG. 2 , BS 1 has the highest transmission quality. Its minimum transmit power forms the lower limit of a tolerance interval referred to as the handover margin HO, which, in a normal operating condition of the radio communications system, has a width of e.g. 5 dB. Further base stations BS 2 , BS 3 , BS 4 , BS 5 lie within this interval. Any available base stations with a higher minimum transmit power are not shown.
In the radio communications system considered here as an example, the active set comprises a maximum of 2 elements in the normal operating condition, i.e. a call connection of the mobile terminal runs simultaneously via a maximum of two base stations, which transmit the same user data to or receive the same user data from the mobile terminal. In FIG. 2 , the active set comprises the stations BS 1 and BS 2 shown by a solid black dot, which require the lowest transmit power.
At regular intervals, the mobile terminal checks the transmission quality of the base stations in whose range it is located, e.g. by measuring the receive field strength of synchronization signals which the base stations continuously emit. This check may remain restricted to stations whose receive field strength on the mobile terminal does not fall below a given percentage of the receive field strength of the strongest station BS 1 . These stations are generally identical to those in the HO margin. In the case of FIG. 2 , a check of this type indicates that, after the stations BS 1 and BS 2 of the active set, stations BS 3 and BS 4 are the next weakest stations. The mobile terminal reports these two stations to the administration unit as candidate stations which would be suitable replacements for the stations BS 1 and BS 2 , if the connection to the latter were to be interrupted. The candidate stations are in each case shown as semi-solid black dots, whereas the weakest station BS 5 is shown by an unshaded circle in the diagram.
While the mobile terminal is moving, the strength ratios of the individual stations may shift in relation to one another. If, for example, the receive signal from BS 3 becomes stronger than that from BS 2 , BS 2 is excluded from the active set and is replaced by BS 3 . To avoid having to change the composition of the active set too frequently in the event of substantially changing receive conditions, a hysteresis is provided, whereby receive signals are replaced by one another only if the receive signal of the station which is getting stronger is, for example, 1 dB stronger than that of the station which is getting weaker.
In this way, it is ensured in the case of most applications that the active set constantly contains base stations with adequately high transmission quality, so that the occasional exclusion of a station from the active set and its replacement by a differentstation does not adversely affect the communication of the mobile terminal.
If the quality of transmission between the mobile terminal and the stations of the active set is generally poor, situations may easily arise in which, within a time interval between two transmission quality checks, the connection to all stations of the active set is interrupted. This risk can be reduced by allowing a larger active set, i.e. by providing multiple-redundancy transmission from and to the mobile terminal. However it is clear that a solution of this type would severely restrict the total capacity of a radio communications system, and would therefore increase costs for operators and users.
FIGS. 3 a to 3 c shows a situation of this type, in which the minimum transmit powers of all stations BS 1 to BS 4 are clearly higher than in the case shown in FIG. 2 . The periodic checking of the transmission quality, which can be carried out in the stations of the active set in particular by measuring the bit error rate or the signal interference ratio, delivers critically poor values, so that a slight further deterioration could result in interrupted communication. In this situation, the mobile terminal transmits a special warning signal, which is intercepted by the stations of the active set BS 1 and BS 2 and forwarded to the administration unit. The radio communications system then switches to a temporary operating condition in which the number of stations which may belong to the active set is increased, whereby the administration unit adds the candidate stations BS 3 and BS 4 to the active set and transmits a related message back to the mobile terminal. The mobile terminal then also begins, in addition to the channels used by BS 1 and BS 2 , to process receive signals on those channels which the administration unit has allocated to the base stations BS 3 and BS 4 , and to reconstruct the user data intended for it from the signals received on these four channels.
FIG. 3 b shows this temporary operating condition, wherein all four base stations BS 1 to BS 4 are shown here as solid black dots:.
FIG. 3 c shows a situation at a later time, where, on the basis of the situation shown in FIG. 3 b , the transmission quality of the base stations BS 1 and BS 2 has simultaneously deteriorated, whereas the transmission quality of BS 3 has clearly improved so that it is now the strongest station and defines the position of the HO margin. Since BS 3 has belonged to the active set since the condition shown in FIG. 3 b , the mobile terminal has been able to communicate constantly via it, and the deterioration in the transmission quality of BS 1 and BS 2 has not resulted in interrupted communications. A transmission quality check carried out at the time shown in FIG. 3 c has indicated that BS 1 and BS 2 have moved out from the HO margin. The mobile terminal reports this to the administration unit, which then excludes BS 1 and BS 2 from the active set, i.e. user data intended for the mobile terminal are no longer forwarded to these stations. The active set then comprises only the stations BS 3 and BS 4 , whereby the normal operating condition is restored and a soft handover is completed.
If BS 1 and BS 2 , in contrast to the situation shown in FIG. 3 c , were still located within the HO margin, the return to the normal operating condition would be completed in that, following a predefined duration of the temporary operating condition of e.g. 10 seconds, the mobile terminal reports the two poorest stations to the administration unit during a transmission quality check, whereupon the administration unit excludes these stations from the active set.
The method can also be applied to radio communications systems which provide different base station transmit powers depending on the receive situation on the mobileterminal. To control the transmit power, the mobile terminals of such a system transmit commands in the form of
“TPC” (Transmit Power Control) bits to the base stations to cause them to reduce or increase their transmit power. If a base station receives a command to reduce the transmit power from a mobile terminal in the temporary operating condition, this is a sure indication that the transmission quality of this terminal is again high. The reception of a command of this type therefore also gives cause to return to the normal operating condition.
FIG. 4 shows a different situation with critically poor transmission conditions. BS 1 is again assumed to be the strongest base station. The station BS 2 still remains within its HO margin HO, whereas the next weakest stations BS 3 and BS 4 lie outside. In its periodic transmission quality check, the mobile terminal therefore finds no suitable candidate stations in the HO margin HO, and consequently also reports none to the administration unit. This is uncritical as long as the transmission quality of the base stations of the active set is high, i.e. there is still no risk of sudden interruption of the communication with them. If, however, as in the situation considered here, the transmission quality of the active set is also poor, the mobile terminal increases the HO margin to e.g. 10 dB, reports this to the administration unit and begins to look for candidate stations in this increased HO margin HO′. It finds the stations BS 3 and BS 4 in the increased HO margin HO′ and reports them to the administration unit. If the administration unit then receives the warning signal from the mobile terminal, it switches to the temporary operating condition by adding BS 3 and BS 4 to the active set. The return to the normal operating condition takes place as described above.
FIG. 5 describes a situation in which the HO margin of the strongest station BS 1 contains no further station. Since, in the normal operating condition, only those stations which lie within the HO margin HO are included in the active set, the active set in this case is smaller than the maximum value of 2 which is used here as an example. If the transmission quality of the station BS 1 falls under a limit value, the mobile terminal extends the HO margin, as described with reference to FIG. 4 . In the extended margin HO margin HO′, it finds the station BS 2 and reports it as a candidate station. On receiving the warning signal, the administration unit switches to the temporary operating condition and adds BS 2 to the active set. The active set then contains two stations, i.e. no more than is also permitted in the normal operating condition. If both stations BS 1 and BS 2 lie in the original HO margin HO at the end of the temporary operating condition, the station BS 2 remains in the active set; all that is then required in order to return to the normal operating condition is for the mobile terminal to reverse the extension of the HO margin HO.
Various permutations of the method described here are possible. Thus, for example, the changeover from the narrow to the extended HO margin HO can be made dependent on an approval of the administration unit.
The maximum permissible number of base stations in the active set may be greater than 2. For the maximum number of candidate stations which are reported to the administration unit, a fixed value can be predefined which is greater than 2, but can also be 1. Instead of this, however, a maximum number of stations which are permitted to belong to the active set in the temporary operating condition can also be predefined. If the active set does not attain its maximum permissible size in the normal operating condition, correspondingly more candidate stations can then be measured and added in the temporary operating condition to the active set.
Instead of a receive quality check by measurements on the mobile terminal, or in addition to these measurements, corresponding measurements can also be carried out on the base stations of the active set and the temporary operating condition can be initiated if these measurements reveal a signal power which is too low, a bit error rate which is too high or a signal interference ratio which is too low. Since each base station can only measure its own transmission quality, the measurement results are transmitted to the administration unit, which, with the knowledge of the transmission qualities reported by the stations of the active set and, where appropriate, by the mobile terminal, makes a decision on the transition to the temporary operating condition.
Furthermore, base stations can independently apply to the administration unit as candidate stations for a specific terminal if they do not belong to its active set, but are able to receive its radio signal well. Here, it can be provided that a base station applies particularly if its transmission capacity is poorly utilized. If a station of this type is added if necessary to the active set, this loads the capacity of the radio communications system less than in the case of a heavily utilized station.
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. | A radio communications system has a plurality of transmitter/receiver stations. At a certain point in time, a first set of said transmitter-receiver stations forms a group of active stations, which communicate with a mobile terminal device. When a requirement is detected, after a connection has been relayed, the number of active of stations is increased by at least one additional station. Thereafter, at least the station having the lowest transfer quality is removed from the active stations in order to close the connecting relay. | 7 |
FIELD OF THE INVENTION
The present invention is directed to dark look LED automotive lighting. More particularly, the present invention is directed to dark look LED automotive lighting, used as but not limited to external signal lighting.
BACKGROUND OF THE INVENTION
Automobile manufacturers are constantly improving vehicles by improving reliability, improving performance and developing devices which may be useful in succeeding generations of vehicles. As an aspect of vehicle design, automotive lighting evolves as vehicles improve. As automotive lighting evolves, there is a general need to minimize power consumption and to enhance performance and reliability, while at least maintaining and perhaps improving conspicuity. With respect to automotive lighting, it is important to have lighting schemes which not only have a pleasing appearance, but for the benefit of prospective customers, differentiate vehicles using those lighting schemes from other vehicles.
Since LEDs draw relatively little current, can last the life of a vehicle, illuminate almost instantaneously and produce little heat; LEDs are of interest as automotive lighting arrangements evolve. An attractive and distinct appearance is important for LED lamps located on the rear of the vehicle because drivers necessarily focus most of their attention on the rear surface of vehicles in front of them. This is because tail lamps of preceding vehicles indicate the presence of preceding vehicles at night, and brake, turn and hazard lamps at any time caution following vehicles.
Ambient sunlight is a consideration when designing automotive lighting because ambient sunlight can obscure signal lamp functions when reflected therefrom. Since individual LEDs are typically not as bright as individual incandescent bulbs currently used as signal lamps on automotive vehicles, the reflection of ambient sunlight from signal lamps is a concern.
SUMMARY OF THE INVENTION
In view of the aforementioned considerations, the present invention is directed to an automotive lamp comprising an array of light emitting diodes (LEDs) supported within the lamp. A bezel having a dark surface for absorbing visible light from external sources is positioned adjacent to the LEDs. The dark surface of the bezel has a high gloss finish or other reflective area at least adjacent the LEDs to reflect light from the LEDs, while the dark surface absorbs visible light from external sources. A lens of light transmitting material covers the array of LEDs.
In a further aspect of the invention, the dark surface is substantially black and the lens is clear.
In another aspect of the invention, the automotive lamp is a rear combination lamp assembly including a first array of LEDs which emit red light to function both as a tail light and as a brake light. The rear combination lamp assembly further comprises a second array of LEDs that in one embodiment emit amber light to provide turn and emergency signals which flash. A bezel surrounds the LEDs and is substantially black in color to absorb incoming light from exterior sources, such as sunlight, and includes a gloss finish to reflect light rearwardly from the LEDs. The bezel is mounted in a housing and a lens is positioned over the bezel and the arrays of LEDs.
In a preferred arrangement of the LEDs within the rear combination lamp assembly, the LEDs are arranged in vertical columns and at least a rearwardly facing reflector is positioned adjacent to the columns of LEDs.
In a preferred embodiment of energizing the LEDs, the LEDs of the first array are connected to a power supply which is connected with both a road light control system and a brake system in a vehicle. The power supply has a first mode of a reduced duty cycle for illuminating the LEDs of the first array only as taillights, and has a second mode activated by the braking system for delivering current at a higher percentage of the duty cycle to the LEDs of the first array. This illuminates the LEDs of the first array more brightly then when used as tail lights in order to provide brake lights. In still a further aspect of the invention, the power supply is connected to the second array of LEDs that emit flashing amber or red light and provides current thereto at a higher percentage of the duty cycle to contrast with the tail lights provided by the first array, as well as to be visible in conjunction with the second array, if the first array is brightly lit indicative of the vehicle's brakes being applied.
In still another aspect of the invention, the aforedescribed automotive lamp is used as a center, high mounted, stop lamp (CHMSL) comprising an array of red light emitting LEDs surrounded by a bezel which is substantially black in color to absorb incoming light from exterior sources while having a gloss finish providing reflector elements adjacent to the LEDs to reflect light from the array of red LEDs rearwardly. The bezel is mounted by a housing and a lens is positioned over the bezel and the array of red LEDs.
In further aspects of the CHMSL the red LEDs are arrayed in a line and the lens is clear.
In still another aspect of the invention the aforedescribed automotive lamps are utilized in combination in an arrangement of rear signal lamps on an automotive vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a schematic view illustrating light from the sun illuminating the rear of an automotive vehicle;
FIG. 2 is a rear view of the automotive vehicle of FIG. 1 ;
FIG. 3 is a rear view similar to FIG. 2 but showing tail lamps of the automotive vehicle illuminated;
FIG. 4 is a view similar to FIGS. 2 and 3 but showing stop signals illuminated;
FIG. 5 is a view similar to FIGS. 2–4 but showing a left turn signal illuminated;
FIG. 6 is a perspective view of a rear combination lamp configured in accordance with the principles of the present invention;
FIG. 7 is an elevation taken along line 7 — 7 of FIG. 6 showing optional side marker illumination;
FIG. 8 is a rear view of a center, high mounted, stop lamp (CHMSL) configured in accordance with principles of the present invention;
FIG. 9 is an elevation taken along line 9 — 9 of FIG. 8 , and
FIG. 10 is a schematic diagram showing a power supply arrangement used with each of the rear combination lamps of FIGS. 2–5 , shown in FIG. 6 .
DETAILED DESCRIPTION
Referring now to FIG. 1 there is shown an automotive vehicle 20 having a rearwardly facing area 21 on which is disposed a pair of rear combination lamps 23 a ( b ) and a center high mount stop lamp (CHMSL) 24 . The pair of rear combination lamps 23 a ( b ) and the CHMSL 24 are dark in color so as to not reflect exterior light rays, such as light rays 25 and 26 from an external source such as the sun 27 , back to an observer 28 in a following vehicle. This is because dark objects absorb rather than reflect visible light. Since the rear combination lamps 23 a ( b ) and CHMSL 24 absorb the externally emitted light rays 25 and 26 , light rays 29 and 30 emitted by the rear combination lamps and CHMSL are not obscured by the light rays 25 and 26 , and are thereby clearly visible to the observer 28 . As will be explained hereinafter, this is accomplished by having dark surfaces of the lamps 23 a ( b ) and 24 black, or substantially black in color, with a glossy surface, so that when the lamps are illuminated, they are not obscured by exterior light sources, such as light from the sun 27 or from other sources such as headlights of following vehicles.
Referring now to FIGS. 2–5 where the rear area 21 of the vehicle 20 is shown, FIG. 2 shows the vehicle as it appears to a following driver in normal daylight. In FIG. 2 , the rear combination lamps 23 a and 23 b and the CHMSL lamp 24 are not illuminated, whereas in FIG. 3 , the rear combination lamps 23 a and 23 b are illuminated as tail signal lights 31 a and 31 b (preferably red in color) when the vehicle is traveling at night or twilight, in fog or in any other situation, such as with a group of other vehicles (convoy), where tail lights of vehicles are illuminated.
In FIG. 4 , red signal stop lights 32 a and 32 b are substantially brighter than the red signal tail lights 31 a and 31 b of FIG. 3 , notifying a following vehicle that brakes have been applied in the vehicle 20 . In addition to illuminating the red signal stop lights 32 a and 32 b in the combination lamps 23 a and 23 b , respectively, a red signal stop light 34 in the CHMSL 24 is illuminated. The red signal stoplights 32 a , 32 b and 34 are substantially brighter than the red signal tail lights 31 a and 31 b , providing a contrasting stop signal to following vehicles.
Referring now to FIG. 5 , a left turn signal is indicated by the rear combination lamp 23 a as a preferably amber (or red) turn signal light 35 a which flashes. While “amber” is a required color for some turn signals in jurisdictions, such as the European Union; “red” or “white” is acceptable in other jurisdictions. For emergency vehicles “orange” or “blue” lights are employed and for funerals “violet” lights are also used in various ways. For conventional vehicles the general practice is to have red lamps for tail, stop and rear fog lights; amber or red lamps for turn and hazard signals, and white lamps for backing lights Since the turn signal light 35 a both flashes and is bright, it contrasts with both the tail signal lights 31 a and 31 b and the stop signal lights 32 a and 32 b . If a hazards situation is being conveyed from the driver of the vehicle 20 to other drivers, then the turn signal light 35 a flashes in unison with a turn signal light 35 b.
Referring now to FIG. 6 one of the rear combination lamps 23 a is shown, the other rear combination lamp 23 b being a reverse image thereof. As is seen in FIG. 6 , both the tail signal light 31 a and the stop light signal source 32 a are provided by a first array 40 of first LEDs 42 that emit red light. The turn signal light 35 a is provided by a second array 44 of second LEDs 46 that preferably emit either flashing amber or flashing red light. In the embodiment of FIGS. 6 the first array 40 of first LEDs 42 and the second array 44 of second LEDs 46 are linear and are arranged in vertical columns to provide illumination proximate the vertical edges of the rear area 21 of the vehicle 20 (see also FIGS. 2–5 ). Beneath the two columns formed by the first and second arrays 40 and 44 of the LEDs 42 and 46 , respectively, is a passive reflector 47 having a rear panel 48 and a side panel 49 . The rear panel 48 is primarily visible from the rear area 21 of the vehicle 20 and the side panel 49 primarily visible from the side of the vehicle.
The LEDs 42 and 46 are surrounded by a bezel 50 which is dark in color to absorb rather than reflect exterior light sources such as sunlight (or following headlights), whereby the arrays of LEDs 40 and 44 are not obscured by reflected light rays from exterior light sources (see FIG. 1 ) when viewed by a following driver. Preferably, the bezel 50 is black or substantially black so that substantially all of the light rays 25 and 26 from an external source such as the sun 27 (see FIG. 1 ) are absorbed, however the bezel 50 has a high gloss surface at least in areas such as areas 52 and 54 , which are directly adjacent to and extend obliquely with respect to the LEDs 42 and 46 . Since at least these surfaces 52 and 54 of the bezel 50 are glossy, these surfaces reflect portions 56 and 58 of light emitted by the LEDs 42 and 46 , respectively. Portions of emitted light which do not reflect from the glossy surfaces 52 and 54 of the bezel 50 are directed rearwardly in a direct line of sight to the following observer. By stepping the second array 44 of LEDs 46 with respect to the first array 40 of LEDs 42 , there is less interference between the stop signal light 32 a and turn signal 35 a emitted from the LEDs 42 and 46 , respectively. The portions 52 of the bezel 50 adjacent to the LEDs 42 are above and below the LEDs 42 so as to reflect substantially all of the laterally emitted light from the LEDs 42 back toward the following vehicle. At least some of the light from the LEDs 42 emits laterally, providing at least some side illumination for the rear combination lamps 23 a and 23 b.
The bezel 50 is preferably made of black polycarbonate and the reflective surfaces 52 and 54 may either be at least glossy portions of the black polycarbonate or may be in the shape of small, non-metalized reflector elements surrounding each of the LEDs 42 and 46 . In the preferred illustrated embodiment the entire bezel is molded of black polycarbonate with a continuous glossy surface molded therewith.
The bezel 50 is attached to a housing 70 by a pair of metal push-in clips and at least one screw utilizing a rubber sealing gasket (neither of which is shown) so that the bezel is structurally stable with respect to the housing. In a preferred embodiment, the LEDs 42 project through openings 74 in the bezel 50 and the LEDs 46 project through openings 76 in the bezel, the openings 74 and 76 being adjacent the reflective surfaces 52 and 54 of the bezel.
The first array 40 of LEDs 42 is mounted on a stamped metal circuit 80 that is press fitted or otherwise attached to the back surface of the bezel 50 . The second array 44 of LEDs 46 is attached to a stamped metal circuit that is also press fitted or otherwise attached to the back surface of the bezel. Alternatively, the stamped metal circuits are attached to surface of the housing.
Disposed over the arrays 40 and 46 of LEDs 42 and 46 is a lens 90 . The lens 90 is preferably made of crystal clear (non-colored), medium impact, acrylic plastic having a black acrylic frame around the entire periphery of the lens. The frame is preferably molded integrally to the lens and the combination of the lens and the frame are adhered to the housing 70 using a two-part polyurethane adhesive 91 to combine the housing, lens and lens frame in an integral, closed structure protecting the LEDs 42 and 46 . The housing 70 is attached removably to the rear of the vehicle 20 ( FIGS. 1–5 ) in a conventional manner by using, for example, screws or bolts to mount the rear combination lamp 23 a on the vehicle, the rear combination lamp 23 b being generally configured and mounted on the vehicle in the same manner.
As is seen in FIG. 7 , for certain markets, red side marker LEDs 93 are required. In these situations, the bezel 50 ′ is provided with an additional opening 94 and the LEDs 93 are supported in the housing 70 by a printed circuit board 95 . Preferably, a pair of LEDs 93 provide a third array 96 of LEDs in each of the rear combination lamps 23 a and 23 b to provide side marker illumination for the two rear combination lamps. In a preferred embodiment, the LED or LEDs 93 are mounted to project light through a light transmitting portion of the side marker reflective panels 49 of each rear combination lamp 23 a and 23 b.
Referring now to FIGS. 8 and 9 where the center, high-mounted stop lamp (CHMSL) 24 is shown in isolation, it is seen that the stop signal light 34 of the CHMSL is comprised of an additional array 100 of individual red LEDs 102 . In the illustrated embodiment there are 34 LEDs. While a linear array 100 of LEDs 102 is a preferred arrangement of a CHMSL for a vehicle such as an SUV, this third array 100 of LEDs 102 may be arranged in other configurations, such as lines of LEDs arranged one above the other, or in any other arrangement conveying a signal to a following driver to “stop.”
As is seen in FIG. 9 , the additional array 100 of LEDs 102 providing the CHMSL signal light 34 cooperate with a bezel 104 that has openings 106 therein through which red light from the LEDs passes. The bezel 104 is of a dark material which absorbs exterior light such as ambient sunlight or light from a following headlight, but has reflective surfaces 108 at least adjacent the LEDs 102 . In a preferred embodiment, the bezel 104 is made of a dark plastic, such as black polycarbonate, having a glossy surface which provides the reflective surfaces 108 at least adjacent each LED 102 . The LEDs 102 are mounted on a circuit board 110 positioned behind the bezel 104 , the circuit board being affixed to a housing 112 . The housing 112 is preferably made of a plastic material and supports a clear plastic lens 114 preferably made of an acrylic material. The clear plastic lens 114 preferably has a black acrylic frame. The clear plastic lens 114 , which is preferably a crystal clear acrylic, is bonded to the housing 112 with a two-part polyurethane adhesive 116 to provide a permanently closed integral structure that protects the additional array 100 of red LEDs 102 for the life of the CHMSL 24 .
Referring now to FIG. 10 there is shown a power supply, which is referred to in the art as an LED drive module or an LDM. An LDM 130 a is mounted in the housing 70 of the left rear combination lamp 23 a and an LDM 130 b is mounted in the housing 70 of the right rear combination lamp 23 b . The LDM modules 130 a and 130 b use constant vehicle current at 9 – 16 volts DC. When the outboard lights 31 a and 31 b (see FIG. 3 ) are functioning as taillights, the associated LDMs 130 a and 130 b are operating in a first mode at a 5% duty cycle to provide current to the red LEDs 42 of the first array 40 in each of the rear combination lamps 23 a and 23 b . Consequently, the red LEDs 42 emit light at a reduced intensity when in the first mode.
When the brake pedal of the vehicle 20 is pressed, the LDMs 130 a and 130 b change to a second mode during which the duty cycle is increased, preferably to a full duty cycle, which substantially brightens the red LEDs 42 in both rear combination lamps 23 a and 23 b , signaling a following driver that brakes have been applied in the vehicle 20 .
The CHMSL light 34 is not modulated by the LDMs 130 a and 130 b , but is connected directly to the DC electrical system through a brake pedal detector and is illuminated immediately when the brake pedal is pressed (not shown) with current preferably at a full duty cycle, so that there are three rearwardly facing brake signal lights 32 a , 32 b and 34 (see FIG. 4 ) displayed to following vehicles when the brake pedal in vehicle 20 is pressed.
The rear turn signal lights 35 a and 35 b always operate at a full duty cycle and are therefore always bright when flashing to indicate a left turn 35 a or a right turn 35 b , or when both are flashing in conjunction to indicate an emergency situation. The second LEDs 46 contrast with the first LEDs 42 in the first arrays 40 of the two rear combination lamps 23 a and 23 b . This contrast indicates to following vehicles that the vehicle 20 is turning or that the vehicle is aware of a hazardous condition. The turn signal lights 35 a and 35 b flash together when a caution switch in the vehicle 20 is activated to indicate the presence of a hazard to following drivers. The turn signal lights 35 a and 35 b , positioned inboard of the tail and stop signal lights 31 a and 31 b , are either red or amber and contrast markedly with the red tail lights 31 a and 31 b and stop lights 32 a and 32 b because the turn signal lights 35 a and 35 b continuously flash.
FIG. 10 is the actual circuit diagram of the illustrated embodiment. Although the LEDs 42 and 46 are each physically in single columns in the other drawing figures, other physical arrangements of the LEDs 42 and 46 may be used, such as but not limited to circular or polygonal arrangements.
As seen in FIG. 10 , if a side marker function is utilized with the rear combination lamps 23 a and 23 b , then the LED 93 or the array 96 of LEDs 93 are preferably energized directly by the vehicles DC electrical system to always preferably illuminate at a full duty cycle. The CHMSL 24 is preferably also energized by 9 – 16 volt constant DC current at a full duty cycle taken directly from the electrical system of the vehicle 20 .
The present invention is also applicable to front parking and directional signal lights configured in substantial similarity with the rear combination lights 23 a and 23 b , wherein turn signal LEDs have dark bezels with a reflective portion or element adjacent to the LEDs, so as to indicate turns when flashed one at a time to indicate turning direction, or in unison, to indicate an emergency condition. These lights may also be used as parking lights using amber or white LEDs with dark color bezels having reflective surfaces, such as the aforementioned glossy surfaces.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. | Automotive lamps are configured having at least one array of light emitting diodes (LEDs) supported within the lamps. A bezel is positioned in each lamp adjacent to the LEDs, the bezel having a dark surface, the dark surface having a high gloss finish with reflector shaped surfaces to reflect light from the LEDs while absorbing visible light from external sources. A lens of light transmitting material covers the array of LEDs. The automotive lamp is especially useful as a rear combination lamp having red LEDs serving both tail light and stop light functions, as well as amber or red LEDs providing turn and hazard signals. A center, high-mounted stop lamp (CHMSL), also using an array of LEDs surrounded by a dark bezel with high gloss reflector shaped surfaces, is used in combination with a pair of the rear combination lamps. In one embodiment the rear combination lamps include side marker LEDs. | 5 |
TECHNICAL FIELD
[0001] The present invention relates generally to semiconductor circuit devices and, more specifically, to a circuit for changing the voltage applied to selective portions of a memory array. Such portions include digit line pairs as well as the gate of a transistor used to regulate sense amplifiers.
BACKGROUND OF THE INVENTION
[0002] In the operation of certain semiconductor circuit devices, pullup and pulldown sense amplifiers (sense amps) detect and amplify a small charge stored within a memory cell. In general, two complementary digit lines are attached to a pullup sense amp and a pull down sense amp. At the beginning of a reading operation, both lines are at an equilibrate voltage Veq, which is generally between the potential of a voltage source used to operate the semiconductor device (V CC ) and ground potential (0 volts). While Veq is changeable either intentionally or inadvertently through a defect, Veq is ideally equal to V CC /2 during non-test operations. This midpoint voltage is defined as DVC 2 .
[0003] One of the digit lines is coupled to a memory cell. The reading process involves a discharge from the memory cell to the corresponding digit line, which creates a slight difference in voltage between the two digit lines. This difference is then amplified by the sense amps: the digit line with the slightly lower voltage has its voltage further decreased by the pulldown sense amp, and the voltage of the other digit line is increased by the pullup sense amp. Once the voltage difference has been amplified, the digit lines can then be used to operate less sensitive circuitry.
[0004] Between reading cycles, it is necessary to return the complementary digit lines to Veq. This occurs during what is known as a precharge cycle, wherein equilibration transistors short the complementary digit lines together. Further, a signal having a potential of DVC 2 is communicated from a DVC 2 voltage generator to the shorted digit lines through a bleeder device.
[0005] Concerning the operation of the sense amps, it should be noted that pulling down the voltage of a digit line involves coupling the line to ground through a pulldown transistor. Because an entire row of digit line pairs often connects to the same pulldown transistor through a common node, the pulldown transistor will most likely have to draw current from one line of each of several pairs. In doing so, there is a risk that the transistor will become saturated with current and therefore become slower in pulling down the voltage of additional digit lines. This may lead to errors in reading, especially if an entire row of memory cells is storing logic 1's except for one cell storing a logic 0; for once the logic 0 is discharged, a slow pulldown may result in an improper reading of that logic 0 value.
[0006] One known way to solve this problem is to include an optional active area in the gate of the pulldown transistor. The increased size of the gate raises the threshold at which the pulldown transistor becomes saturated. However, one of ordinary skill in the art will appreciate that this solution requires a costly metal mask change. Further, any attempt to speed up the slowed pulldown raises other problems in reading, as disclosed in U.S. Pat. No. 5,042,011, by Casper, et al. The Casper '011 reference discloses that pulling down the common node too quickly may result in capacitive coupling between the sources and drains of the sense amp's transistors. During capacitive coupling, both digit lines in one sense amp are pulled down before the common node is pulled down low enough to turn on one of the sense amp transistors. When the sense amp finally turns on, it shorts out the capacitive coupling, bouncing the digit lines and, in the process, creates line noise that will interfere with the ability to read the data properly.
[0007] Early saturation and capacitive coupling could be avoided if one knew the margin— the difference in voltage between a logic 0 signal and a logic 1 signal—that the pulldown transistor was capable of accommodating. The only way to do so, as taught by the prior art, is to separate the pulldown transistor with a laser and probe the gate.
[0008] As an alternative to determining the sense amp's margin, one could simply test the sense amp's ability to operate at the given source voltage used in non-test operations. Prior art suggests entering a series of test data patterns into memory. Logic 1's are written to the cells of each memory array, with the exception of one column of logic 0's. As a result, each row contains only one cell storing a logic 0, thereby creating the most likely circumstance for an error in reading the data. The data in the array is then read and checked for errors. Once the first group of test data has been processed, a second sample of test data is entered with the logic 0's written to the next column. This process repeats until a logic 0 has been written to and read from every cell in any given row in the memory array. The results will indicate the pulldown transistor's ability to read data accurately. The problem with this process, however, is that it is time consuming to enter multiple samples of test data.
[0009] Thus, there is a need in the art for a quicker circuit and method for testing the capabilities of a sense amp. Further benefit would be derived if this test could indicate the margin of the sense amp's pulldown transistor.
[0010] In addition to inadequate pulldown transistors, other problems, such as defects arising during the processing of semiconductor devices, may contribute to reading errors. Various techniques involving equilibration of the complementary digit lines can be used during testing to detect these problems. For example, occasionally a digit line will inadvertently have a short to ground. As a result, the potential of that digit line will leak towards 0 volts. To detect this problem, prior art teaches extending the time for the precharge cycle during a test mode. If the short has a low enough resistance, the short will overcome the charging ability of the DVC 2 voltage generator, which remains coupled to the digit lines, and Veq of the digit lines will decrease. Thus, a longer precharge cycle allows Veq to lower even further. As a result, line noise is more likely to register as a logic 0 discharge on the digit line when in fact the storage cell contains a logic 1 and has not yet discharged. Alternatively, assuming that a logic 1 is properly discharged and sensed, a reading error is still likely: Veq may be so low due to the short that the pullup sense amp may not be able to pull up the digit line's voltage in time to register as a logic 1 for purposes of driving external circuitry. Increasing the likelihood of error is desirable in the test mode, as it helps to identify errors that would affect non-test operations. Further, a reading error occurring after this extended precharge cycle will indicate the nature of the defect—in this case a short in at least one of the digit lines. However, this testing process can be time consuming. As an example, a 64 meg DRAM having a 16 meg×4 configuration requires approximately 170 seconds to carry out this test. It would be a benefit to the art to have a faster way to test for this problem.
[0011] A second problem that could be detected by altering the equilibration rate of the digit lines involves a short between the cell plate and the digit line. The typical technique for discovering this problem is to initiate a long RAS (Row Address Strobe) low signal. During the low RAS, the digit lines are not equilibrated. Rather, they are charged to their complementary voltage levels. Ideally, once the low RAS ends and the lines are shorted, both digit lines should approach a Veq level of DVC 2 . However, a short between one of the digit lines and the cell plate will allow the DVC 2 generator 68 to change that digit line's voltage during the RAS low period. Thus, once the lines are shorted, their respective voltages will meet at a different Veq level. This will affect the margin between Veq and the voltage corresponding to one of the logic values and thereby increase the likelihood of a reading error. Eventually, the signal from the DVC 2 voltage generator will restore the proper equilibrate voltage once the RAS low signal ends. Nevertheless, for purposes of detecting this problem before non-test operations begin, it would be desirable to slow the restoration of the proper Veq level.
[0012] A third example concerns a defect that could exist within the memory cell's storage capacitor, such as a defect in a nitride layer acting as a dielectric between the memory cell's conductive plates. Such a defect could cause a short within the storage capacitor. Because the storage capacitors are coupled to the DVC 2 voltage generator, a defective capacitor “storing” a 0 volt charge, representing a logic 0, will slowly charge to the DVC 2 level. The closer the storage capacitor approaches a DVC 2 charge, the more likely that a logic 1 value may be misread during the next reading. One way to detect this problem in the prior art is to initiate a static refresh pause, wherein the memory cell's access transistor remains deactivated for a longer time than usual—generally 100 milliseconds. As a result, the capacitor, which should be storing a logic 0, has a longer time to charge to a higher voltage, thereby making an error in the next reading cycle more likely.
[0013] Once again, a speedier test is desired. The defect might be detected earlier if the problem were exacerbated to the point where the leaked charge for the stored logic 0 exceeded the equilibrate charge of the digit lines. As a result, a logic 1 would be read from the cell even though it was known that a logic 0 had been written. One could speed up the leakage into the storage capacitor by forcing DVC 2 to a higher voltage. However, the equilibrate voltage of the digit lines would also increase accordingly and remain higher than the voltage of the charge in the storage capacitor. Thus, forcing DVC 2 would not appreciably increase the ability to detect an error unless the equilibration of the digit lines could be slowed. The only way to do this in the prior art is through the use of a costly metal option to change the gate voltage of the bleeder device.
SUMMARY OF THE INVENTION
[0014] Given the need for regulating the drive of a sense amp, as well as the need for regulating the equilibration signal from a DVC 2 voltage generator, a test circuit is provided for varying the voltage of a signal used to drive a connection device that allows electrical communication within a semiconductor circuit. One preferred circuit embodiment includes a contact pad for carrying a range of test voltage signals to said connection device. In another preferred circuit embodiment, a regulator circuit enables a series of discrete voltages to drive the connection device.
[0015] In one set of applications involving the regulation of a sense amp, the connection device comprises a sense amp's voltage pulling transistor. Any circuit embodiment covered by the present invention can be used to test drive the transistor. In a preferred method of use, a test data pattern is entered and the data is read several times, with a different voltage driving the sense amp's pulldown transistor each time. One advantage of this preferred method is that it reduces the need for entering several elaborate test data patterns and, therefore, allows for quicker testing of memory arrays. A second advantage is that the embodied method and devices allow a determination of the lowest supply voltage that can be used during normal operation without errors in reading data. Yet another advantage is the ability to determine the highest supply voltage, and therefore the fastest reading speed, that can be used during normal operations without causing capacitive coupling. In doing so, the preferred circuit embodiments and method increase the sense amp's ability to distinguish between a logic 0 voltage and a logic 1 voltage without physically altering the sense amp. Further, in the process of determining the lowest and highest voltages at which the sense amp is capable of functioning, the preferred embodiments and method also provide a way to ascertain the margin without dissecting components of the sense amp.
[0016] Concerning the specific errors that may be detected in relation to equilibrating the digit lines, the connection device comprises an isolation bleeder device coupled between the DVC 2 voltage generator and a digit line pair. The circuit embodiments provide a test mode apparatus for driving the bleeder device in order to slow or quicken the equilibration of the digit line pair. Applying these embodiments provides the advantage of a quicker detection of defects such as a short from a digit line to ground, a short from a digit line to a cell plate, and a short within the storage capacitor of a memory cell. The embodiments also provide an alternative advantage of overcoming the influence of these defects during non-test modes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 depicts a row of n-channel pulldown sense amps with associated D, D*, and WL lines; a pullup sense amp; and a series of memory cells, as found in the prior art. FIG. 1 also shows a digit line equilibration circuit as found in the prior art.
[0018] [0018]FIG. 2 is a graph indicating the voltage of the conductive paths D and D* over time in the event that a memory cell storing a logic 0 discharges to D. FIG. 2 also demonstrates the resulting amplification of the difference in voltage.
[0019] [0019]FIG. 3 is a graph demonstrating the relationship between drive current (I DV ) and the gate-source voltage of a pulldown transistor (V GS ) at various levels of voltage applied to the gate (V GATE ).
[0020] [0020]FIG. 4 details one exemplary circuit embodiment in accordance with the present invention as used with a sense amp.
[0021] [0021]FIG. 5 illustrates a second exemplary circuit embodiment in accordance with the present invention as used with a sense amp.
[0022] [0022]FIG. 6 shows a third exemplary circuit embodiment in accordance with the present invention as used with a sense amp.
[0023] [0023]FIG. 7 a is a schematic of a portion of a memory array depicting an embodiment of the current invention as used in the digit line/cell plate region of a memory array. FIG. 7 a further depicts a first type of possible defect within said memory array.
[0024] [0024]FIG. 7 b is a graph illustrating the effect of the first defect and a first embodied method of the current invention.
[0025] [0025]FIG. 7 c is another graph illustrating the effect of the first defect and the first embodied method of the current invention.
[0026] [0026]FIG. 8 a depicts a cross-section of a portion of a memory array including a second type of defect.
[0027] [0027]FIG. 8 b demonstrates the effect on a memory array of the second type of defect as well as the effect of a second embodied method of the current invention.
[0028] [0028]FIG. 8 c further demonstrates the effect on a memory array of the second type of defect as well as the effect of a third embodied method of the current invention.
[0029] [0029]FIG. 8 d depicts the effect of a fourth embodied method of the current invention as it relates to the second type of defect.
[0030] [0030]FIG. 9 a is a schematic of a portion of a memory array depicting a third type of defect in said memory array.
[0031] [0031]FIG. 9 b is a graph indicating the effect of the third type of defect.
[0032] [0032]FIG. 9 c is a graph illustrating a method in the prior art for detecting the third type of defect.
[0033] [0033]FIG. 9 d is a graph illustrating the effect of a fifth embodied method of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] [0034]FIG. 1 illustrates the general configuration of sense amps in a memory array. A pulldown sense amp 20 includes cross coupled n-channel transistors Q 1 and Q 2 , as well as a pulldown transistor Q 3 , which is an n-channel transistor driven by a signal designated as LENSA. These elements play a part in sensing and amplifying a voltage difference between D and D* caused by shorting a memory cell 22 to D by way of access transistor Q 4 . The sources of Q 1 and Q 2 are connected to a common pulldown node 24 , and the gate of each is connected to the other's drain. The gate of Q 1 also connects to the line D*, whereas the gate of Q 2 connects to the line D.
[0035] As discussed above, each line D and its corresponding line D* are initially at the same voltage DVC 2 . For purposes of explanation, DVC 2 is assumed to be 1.65 volts, or one half of the source voltage V CC , which is 3.3 volts. Lines D and D* connect to opposite sides of each sense amp 20 . Common pulldown nodes 24 found in the sense amp arrays will also be at DVC 2 . A signal sent through the path WL will cause a storage capacitor 150 of particular memory cell 22 to discharge to a line D, thereby slightly changing D's voltage while the voltage of D* remains at DVC 2 . Again, for purposes of explanation, a memory cell discharge will be assumed to cause a 0.2 volt difference in D. The pulldown sense amp 20 will then turn on when the common pulldown node 24 is one transistor threshold voltage below D or D*, whichever is highest. For instance, if a memory cell 22 is storing a logic 1, a discharge to D will increase D's voltage to 1.85 volts. As a result, the pulldown sense amp transistor gated by D (Q 2 ) turns on faster than the one gated by D* (Q 1 ). With transistor Q 2 on, D*'s voltage is pulled down from 1.65 volts towards ground as the common pulldown node 24 is pulled down as well. Further, the lowering voltage of D* serves to turn on the pullup sense amp transistor gated by D* (Q 14 ) before the other pullup sense amp transistor turns on. The voltage supply V CC then charges line D.
[0036] On the other hand, if the memory cell 22 had been storing a logic 0, then a discharge to D would slightly lower D's voltage to 1.45 volts. The pulldown sense amp transistor gated by D* (Q 1 ) would turn on first and D's voltage would be further decreased toward ground by the pulldown sense amp, thereby allowing the pullup sense amp to increase D*'s voltage toward V CC . In this way, a small voltage difference between D and D* is sensed and amplified. Once the voltage difference has been amplified, D and D* can drive less sensitive circuitry not shown in FIG. 1. It should be noted that, if a logic 0 is transmitted to D, then the pulldown sense amp need only pull down D from 1.45 volts. If a logic 1 is transmitted to D, then the pulldown sense amp must pull D* from the higher DVC 2 level—1.65 volts.
[0037] Therefore, if many logic 1's in a memory array row are read, the extra voltage that must be pulled contributes to saturating the pulldown transistor Q 3 with drive current, thereby slowing any further pulldown. The problem created by slow pulldown is illustrated in FIG. 2, where slope X denotes the initial discharge to D from a memory cell 22 storing a logic 0. FIG. 2 further illustrates the amplification of the difference in voltage between D and D*. Slope Y denotes the time required for D to drop in voltage given a situation where a row of cells contains a roughly equal number of logic 1's and logic 0's. Should there be many logic 1's read amongst a single logic 0, then the outcome changes: as the logic 0 is read, the pulldown transistor Q 3 , having approached saturation, takes much longer to pull down D's voltage. This result is illustrated by slope Z. Other circuitry elements (not shown) that are driven by D may read D before its transition to a lower voltage has been completed. As a result, a logic 0 value may be misread as a logic 1.
[0038] As illustrated in FIG. 3, increasing the voltage to the gate of the pulldown transistor allows the transistor to pulldown more current before saturation. One preferred embodiment of the current invention that uses this principal is detailed in FIG. 4, where the pulldown transistor Q 3 is driven by a test circuit 26 through an inverter 27 . In this embodiment, the inverter 27 comprises a p-channel transistor Q 6 and an n-channel transistor Q 8 . The coupled gates of inverter transistors Q 6 and Q 8 form an input node 28 for receiving a signal ENSA*, which may be V CC , ground, or a signal from another driver. The coupled drains of the inverter transistors Q 6 and Q 8 output the LENSA signal that drives the pulldown transistor Q 3 . The source of Q 8 is coupled to ground. The source of Q 6 is coupled to a source node 30 that branches into a first conducting path 32 and a second conducting path 34 . The first conducting path 32 is coupled to an n-channel transistor Q 10 , which has a channel width-to-length ratio of around 500/2. The drain of transistor Q 10 is coupled to a contact pad 36 . It should be understood that the term “contact pad” includes any conductive surface configured to permit electrical communication with a circuit or a node. The gate of transistor Q 10 is coupled to an inverter 60 through another n-channel transistor Q 36 . Together, inverter 60 and transistor Q 36 comprise a latch device, and both are coupled to V CCP . Further, inverter 60 receives a TEST* signal as an input. In addition, the gate of transistor Q 10 is also coupled to a feedback capacitor 62 . This feedback capacitor 62 comprises an n-channel transistor having a size of approximately 100/100, wherein the drain and source are shorted and coupled to the first conductive path 32 . The second conducting path 34 is coupled to a p-channel transistor Q 12 , driven by a signal TEST, which is understood to be the complement of TEST*. The transistor Q 12 is also coupled to V CC , although no voltage source is considered to be a part of the invention.
[0039] During testing, TEST* transmits a low voltage signal which is received by the inverter 60 . In response, the inverter 60 initiates a V CCP signal, sending it through transistor Q 36 which outputs the V CCP signal to the gate of transistor Q 10 , thereby switching on Q 10 . The feedback capacitor 62 serves to maintain and replenish this V CCP signal in the event of leakage. Capacitive coupling between the gate and drain of transistor Q 10 allows Q 10 to carry signals having a range of voltages for modifying the drive of the pulldown transistor Q 3 . Simultaneously, the TEST signal, applying a high voltage to transistor Q 12 , isolates V CC . A test data pattern is entered into the memory cells 22 and read with varying voltages driving the pulldown transistor Q 3 . The data read at various alternate voltages sent through bond pad 36 can be compared with the data as originally written. This series of readings indicates the range of voltages through which the pulldown transistor Q 3 is capable of allowing accurate data readings. Once testing has ended, TEST* sends a high voltage signal and TEST becomes low, thereby isolating the bond pad and allowing the V CC signal to transmit to the pulldown transistor Q 3 .
[0040] The embodiment illustrated in FIG. 5 is a package part of the semiconductor circuit device and receives a plurality of voltage sources with different magnitudes. The test circuit 26 allows selection among these sources for driving the gate of the pulldown transistor Q 3 . The inverter 27 is the same as in FIG. 4. In this exemplary embodiment, however, source node 30 is coupled to three discrete voltage sources. First, source node 30 is coupled to V CCP through a p-channel transistor Q 20 that is driven by a low signal A*. Source node 30 is also coupled to DVC 2 through another p-channel transistor Q 22 that is driven by a low signal B*. Finally, source node 30 is coupled to V CC by way of a p-channel transistor Q 24 . This p-channel transistor Q 24 is gated by the output of a logic unit, such as a NAND gate 46 , which will drive transistor Q 24 in response to receiving a high signal A as a first input and a high signal B as a second input. Given the input vector scheme of this embodiment, one of the transistors Q 20 , Q 22 , or Q 24 will be operable to the exclusion of the other two.
[0041] Thus, a low signal A* will drive the p-channel transistor Q 20 , thereby allowing V CCP to drive the pulldown transistor Q 3 . Simultaneously, signal B will be high, turning off p-channel transistor Q 22 . Further, the NAND gate output will also be high and turn off p-channel transistor Q 24 . If, on the other hand, signal B is low and signal A is high, then only p-channel transistor Q 22 will be on, allowing DVC 2 to transmit to the pulldown transistor Q 3 . Only when both signals A and B are high does the NAND gate 46 output a low signal and allow V CC drive the pulldown transistor Q 3 . The data read at these three voltage levels can then be compared with the data as originally written. It should be noted that this configuration does not require the die space needed for the contact pad 36 .
[0042] Another embodiment concerns varying the voltage applied to a pullup sense amp 40 . As seen in FIG. 1, the pullup sense amp 40 includes cross coupled p-channel transistors Q 14 and Q 16 as well as a pullup transistor Q 18 . As one of ordinary skill in the art understands, there is generally a pullup sense amp 40 corresponding to every pulldown sense amp. Nevertheless, for purposes of clarity, only one pullup sense amp 40 is shown. The sources of Q 14 and Q 16 are connected to a common pullup node 42 , and the gate of each is connected to the other's drain. Further, the gate of Q 14 connects to line D*, and the gate of Q 16 connects to line D. Common pullup node 42 is coupled with pullup transistor Q 18 , which is another p-channel transistor. Pullup transistor Q 18 is also coupled to the voltage source V CC . The pullup transistor Q 18 is driven by a signal LEPSA*. FIG. 6 illustrates that the voltage driving pullup transistor Q 18 may also be varied through the use of a test circuit 26 analogous to that used with the pulldown transistor Q 3 in FIG. 5. FIG. 6 depicts an inverter 27 comprising a p-channel transistor Q 26 and an n-channel transistor Q 28 . The coupled gates of inverter transistors Q 26 and Q 28 form an input pathway 48 for a control signal designated EPSA. The coupled drains transmit the inverted output signal EPSA* which, in turn, is received by a prior art device 50 that outputs the LEPSA* signal used to drive the pullup transistor Q 18 . The source of Q 26 is coupled to V CC , whereas the source of Q 28 is coupled to the test circuit 26 which, in this embodiment, includes three conductive paths. The first path 52 leads to DVC 2 by way of an n-channel transistor Q 30 , which is driven by a signal C. The second path 54 is coupled to a voltage source V BB through an n-channel transistor Q 32 , as driven by a signal D. The third path 56 leads to ground by way of n-channel transistor Q 34 . The gate of n-channel transistor Q 34 is coupled to the output of a NOR gate 58 . The NOR gate 58 accepts signal C as a first input and signal D as a second input and will activate transistor Q 34 only when both signals are low. Further, this embodiment is configured in a manner analogous to the embodiment in FIG. 5, in that signals C and D will never simultaneously activate their respective transistors Q 30 and Q 32 .
[0043] The three n-channel transistors Q 30 , Q 32 , and Q 34 will turn on if a high, or logic 1, signal is transmitted to their respective gates. As with the embodiment shown in FIG. 5 for the pulldown sense amp, the signals and transistors are configured to allow only selective communication between one voltage source and the pullup transistor Q 18 . As a result, if signal C is high, it will latch the n-channel transistor Q 30 and provide electrical communication between DVC 2 and the pullup transistor Q 18 . At the same time, the low signal from D turns off n-channel transistor Q 32 . Under these circumstances, the signals C and D also result in a low signal output from the NOR gate 58 , thereby turning off n-channel transistor Q 34 . Thus, all of the other voltage sources are isolated. Similarly, if signal D is high, then only n-channel transistor Q 32 is turned on and V BB electrically communicates with pullup transistor Q 18 . When both signals are low, the NOR gate 58 outputs a high signal, thereby grounding the source of the n-channel inverter transistor Q 28 . This embodiment has benefits similar to the embodiment in FIG. 5.
[0044] Returning to FIG. 1, a prior art equilibration circuit can be seen as part of the memory device. For purposes of explaining the following embodiments of this invention, V CC is now presumed to be 5 volts. A transistor Q 101 is coupled between digit line D and its complementary digit line D*. The transistor is driven by an equilibration signal EQ. It should be noted that the signal EQ results from a logic function and is distinguishable from the equilibrate voltage Veq, which represents the common mid-range voltage level of the complementary digit lines before a reading operation.
[0045] The signal EQ also drives two additional transistors Q 102 and Q 103 , which are connected together in series at a node 120 . These connected transistors Q 102 and Q 103 are also coupled between lines D and D*. Moreover, node 120 is coupled to a cell plate 138 and a DVC 2 voltage generator 68 through a bleeder device 122 . The DVC 2 voltage generator 68 transmits a cell plate signal CP of voltage DVC 2 to the node 120 . For purposes of explaining the following embodiments of this invention, DVC 2 is now 2.5 volts. The bleeder device 122 is driven by a signal of voltage V CCP , wherein V CCP results from having pumped V CC to an even higher potential.
[0046] At the beginning of a precharge cycle, digit line D and its complementary digit line D* are at different voltages as a result of a discharge of the memory cell 22 during the reading cycle. One line will have a charge equal to the V CC value of 5 volts, while the other line will have a 0 volt charge. The equilibrate signal EQ is then sent, activating transistor Q 101 , which shorts D and D* together. Moreover, the signal EQ activates transistors Q 102 and Q 103 , which not only provide another short between D and D* but also allow the CP signal to be communicated to those lines. As a result, the lines D and D* equilibrate, both gaining a charge of potential DVC 2 (2.5 volts), which is the desired equilibrate voltage Veq in this example. Once the lines are equilibrated, they are ready for further testing.
[0047] For various reasons, a particular portion of the memory array may be defective. Hopefully, testing processes will identify those defects. As discussed above and illustrated in FIG. 7 a , a first defect 124 that may exist as a short to ground of the digit line D. FIG. 7 b illustrates the effect of the first defect 124 . During the precharge cycle, the CP signal is trying to charge the digit lines D and D* to the 2.5 volt DVC 2 level and maintain that level. However, if the resistance of the short is not too great, the first defect 124 may cause the digit lines to discharge toward ground faster than CP can charge them to 2.5 volts. As a result, once the precharge process has ended at time t 1 , the digit lines may be equilibrated at a potential lower than 2.5 volts, such as 1.7 volts. Having a Veq at a level other than DVC 2 makes the memory array susceptible to reading errors. For example, in the present situation illustrated in FIG. 7 b , where Veq is too low, line noise on D occurring at time t 2 is more likely to register as a logic 0 discharge when in fact the storage cell 150 contains a logic 1 and has not yet discharged. Alternatively, assuming that a logic 1 is properly discharged and sensed at time t 2 ′, a reading error is still likely: as seen in FIG. 7 c , Veq may be so low due to the short that the pullup sense amp may not be able to sufficiently pull up the digit line's voltage by the time t 3 , when external circuitry accesses line D. In order to find such a reading error, prior art requires an extended precharge time, up to time t 1 , in order to allow the discharge from the first defect 124 to overtake the charge from CP.
[0048] The current invention, however, provides an alternative to requiring a long precharge time. FIG. 7 a illustrates that the V CCP signal driving the bleeder device has been replaced with the test circuit 26 that applies a different voltage V REG to regulate the bleeder device. In the case of the first defect 124 , the test circuit 26 transmits a signal having a voltage lower than V CCP to drive the bleeder device 122 . This causes a slower charge rate and allows the discharge from the first defect 124 to quickly overtake the charging from CP, as seen by the dashed lines in FIGS. 7 b and 7 c . With the resulting increased disparity between the charge rate and the discharge rate, the precharge period need only endure until time t 1 ′ in order to increase the likelihood of detecting an error.
[0049] The design of test circuit 26 can be the same as those used in FIGS. 4 and 5, wherein a source node 30 has access to at least one test voltage, either through a bond pad 36 or from a discrete voltage source. In this application, however, the source node 30 is coupled to the bleeder device 122 . Furthermore, V CCP is the voltage used in non-test operations to drive the bleeder device, and V CC and DVC 2 are used to slow the charge rate. It should be further understood that the number of voltage options could be increased. Alternatively, the number of voltage options could be decreased to offer only one test voltage and one non-test voltage.
[0050] These circuit embodiments, as well as others falling under the scope of the invention, have uses in detecting other defects. FIG. 8 a illustrates another defect 136 that might occur within a memory array. The cross-sectional view in FIG. 8 a shows the cell plate 138 coupled to a first n-region 140 of access transistor Q 4 . Ideally, the only way for the DVC 2 voltage generator 68 to charge the digit line D through the cell plate 138 is to drive the gate 142 of transistor Q 4 so that the charge may pass from the first n-region 140 to a second n-region 144 . From there, the charge travels through a tungsten plug 146 , which serves as a contact between the second n-region 144 and the digit line D. Occasionally, however, a second defect 136 in the memory array may occur in the form of a short between the cell plate 138 and the tungsten plug 146 . As discussed above, a long RAS low signal is used to detect this second defect 136 . Assuming line D is charged to 0 volts, FIG. 8 b shows that the long RAS signal allows line D to be charged to a higher voltage. Thus, when the low RAS signal ends at time t 1 and the digit lines are shorted to begin equilibration, the digit lines will no longer have an initial tendency to reach an average potential between 5 and 0 volts (2.5 volts). Rather, because line D is now higher than 0 volts, the shorted lines will settle at a higher midpoint, such as 3.5 volts. At this point, the margin between the new equilibrate voltage and the voltage representing a logic 1 has decreased. Thus, an erroneous reading is more likely, as discussed above.
[0051] Conversely, if line D is initially charged to V CC (FIG. 8 c ), the short to the cell plate will cause D's voltage to lower during a long RAS low period. The resulting equilibrate voltage of lines D and D* could be lower than the preferred 2.5 volts. The lower equilibrate would again make an error in reading more likely. In either case, the CP signal will restore the equilibrate voltage to 2.5 volts by time t 2 . However, by decreasing the drive to the bleeder device 122 , any of the embodiments of the current invention will serve to slow down the restoration of Veq to DVC 2 . With restoration time extended to time t 2 ′, any circuit embodiment of the current invention increases the likelihood of detecting errors that would suggest the existence of the second defect 136 . Alternatively, FIG. 8 d shows that a circuit embodiment of the current invention could be used during a non-test mode to compensate for the second defect 136 by driving the isolation device 122 at a higher-than-normal level. As discussed above, the bleeder device 122 is normally driven at V CCP , a voltage level representing one or two V t 's above V CC . The potential V t , in turn, is the threshold voltage of the bleeder device 122 . A further increase in the potential of V CCP would allow the bleeder device 122 to quickly restore Veq to 2.5 volts by time t 2 ″. The shorter restoration period reduces the chances of an erroneous reading.
[0052] [0052]FIG. 9 a demonstrates yet another instance wherein the current invention could shorten test time. This instance concerns a third defect 148 comprising a short that may be caused by a nitride defect within the storage capacitor 150 of a memory cell 22 . It should also be noted that one of the plates of the storage capacitor 150 is in fact the cell plate 138 and is therefore connected to the DVC 2 generator. Given this third defect 148 , FIG. 9 b indicates that the CP signal, having a potential of DVC 2 , will charge the storage capacitor 150 toward that potential even though a logic 0 has been written to that cell for test purposes. During a static refresh pause, the word line WL leading to the memory cell 22 will continuously transmit a low signal, which turns off access transistor Q 4 of the memory cell 22 and allows the storage capacitor 150 to take on a greater charge. With the stored charge having a higher voltage, such as 2 volts, it is more likely that the logic 0 will be misread at line D as a logic 1. In order to speed up the leakage into the storage capacitor 150 , DVC 2 is forced to a voltage higher than the normal 2.5 volts. Unfortunately, this would not result in much benefit under the prior art, as demonstrated by FIG. 9 c : because the CP signal has a voltage of DVC 2 and is in communication with D and D* during the static refresh pause, the CP signal would also charge lines D and D* to a higher voltage. With the circuit embodiments of the present invention, however, a lower voltage could be used to drive the bleeder device 122 and thereby slow the charging of the digit lines, as illustrated in FIG. 9 d . Thus, while D and D* are regulated to substantially remain at 2.5 volts despite the forced DVC 2 voltage, the storage capacitor may be quickly charged to a higher potential, such as 2.7 volts, which exceeds the equilibrate voltage and makes it very likely that a logic 1 will be mistakenly recognized.
[0053] One of ordinary skill can appreciate that, although specific embodiments of this invention have been described for purposes of illustration, various modifications can be made without departing from the spirit and scope of the invention. Concerning the invention as used with a sense amp, for example, a test circuit for the pullup sense amp could be configured to transmit an entire range of voltages through a contact pad, as done with the pulldown sense amp depicted in FIG. 4. In addition, the test circuit 26 in FIG. 6 could be used with a pulldown sense amp. Conversely, the test circuit 26 in FIG. 5 could be used with a pullup sense amp. Moreover, both of these test circuits could be coupled to the same inverter and used to test drive either type of sense amp.
[0054] Further, regarding the embodiments use with a cell plate, it should be noted that the embodiments may be applied for other testing. Any circuit embodiment, for instance, may be used during the precharge cycle discussed above in order to detect a short between a row line and a column line. Moreover, a circuit embodiment of the current invention could also be used during a non-test mode to overcome other defects in addition to the short between a digit line and cell plate, as described above.
[0055] It should also be noted that, given a particular voltage source used in an embodiment, that source can be independent of V CC rather than a mere alteration of V CC , such as V CCP or DVC 2 . Accordingly, the invention is not limited except as stated in the claims. | As part of a memory array, a circuit is provided for altering the drive applied to an access transistor that regulates electrical communication within the memory array. In one embodiment, the circuit is used to alter the drive applied to a sense amp's voltage-pulling transistor, thereby allowing modification of the voltage-pulling rate for components of the sense amp. A sample of test data is written to the memory array and read several times at varying drive rates in order to determine the sense amp's ability to accommodate external circuitry. In another embodiment, the circuit is used to alter the drive applied to a bleeder device that regulates communication between the digit lines of the memory array and its cell plate. Slowing said communication allows defects within the memory array to have a more pronounced effect and hence increases the chances of finding such defects during testing. The circuit is configured to accept and apply a plurality of voltages, either through a contact pad or from a series of discrete voltage sources coupled to the circuit. | 6 |
BACKGROUND
1. Field of the Invention
This invention relates to electronic musical instruments which are simple and fun to use and more particularly to a voice controlled musical instrument.
2. Description of the Prior Art
Musical instruments have traditionally been difficult to play, thus requiring a significant investment of time and, in some cases money, to learn the basic operating skills of that instrument. In addition to frequent and often arduous practice sessions, music lessons would typically be required, teaching the mechanical skills to achieve the proper musical expression associated with that instrument, such as pitch, loudness, and timbre. In addition, a musical language would be taught so that the user would be able to operate the instrument to play previously written songs.
The evolution of musical instruments has been relatively slow, with few new musical instrument products taking hold over the past several hundred years. The introduction of electronics-related technology, however, has had a significant impact on musical instrument product development. The music synthesizer, for example, together with the piano keyboard interface/controller, has vastly expanded the number and variety of instrument sounds which can be produced by a person who has learned to play a single instrument--that of piano or keyboards. The requirement remained, however, that for someone to operate a synthesizer, that person would have to learn at least some of the fundamentals of music expression associated with playing a piano.
Therefore, for those people who wanted to be able to express themselves musically, but had not learned to play an instrument, or wanted to be able to make many instrument sounds without learning how to play each instrument, there was still a significant time investment required to learn the skill, with no assurance that they could ever reach a level of proficiency acceptable to them.
A variety of methods have been proposed to use the human voice to control a synthesizer, thus taking advantage of the singular musical expression mechanism which most people have virtually anyone who can speak has the ability to change musically expressive parameters such as pitch and loudness. One such method is described in U.S. Pat. No. 4,463,650, by Robert Rupert, issued Aug. 7, 1984 incorporated herein by reference. In the Rupert device, real instrumental notes are contained in a memory with the system responsive to the stimuli of, what he refers to as, "mouth music" to create playable musical instruments that will respond to the mouth music stimuli in real time.
The difficulty in practice with using the voice as a controller of a musical synthesizer is that some people have little real or perceived ability to reach pitches in a manner accurate enough to believe they sound good. Even trained vocalists have vocal characteristics such as frequency and interval which are unstable and to some degree inaccurate. Such frequency error or instability goes virtually unnoticed by any one who hears the vocal tone directly. However, the frequency error or instability of the output tone signal can be distinctly perceived by any one when he hears a vocal tone processed by a conventional voice-controlled music synthesizer, as that suggested by Rupert. As a result, there is some segment of the population which may not perceive the voice controlled music synthesizer, alone, as a viable route to personal musical expression and/or entertainment.
One such solution is described in European Pat. No. 142,935, by Ishikawa, Sakata, and Obara, entitled "Voice Recognition Interval Scoring System", dated May 29, 1985. In this patent, Ishikawa et. al., recognize the inaccuracies of the singing voice and "contemplates providing correcting means for easily correcting interval data scored and to correct the interval in a correcting mode by shifting cursors at portions to be corrected". In a similar attempt to deal with the vocal inaccuracies, a device described in U.S. Pat. No. 3,999,456 by Masahiko Tsunoo et al, issued Dec. 28, 1976, utilizes a voice keying system for a voice-controlled musical instrument which limits the output tone to a musical scale. The difficulty in employing either the Ishikawa or the Tsunoo devices for useful purposes is that most untrained musicians will not know which scales are appropriate for different songs and applications. The device may even be a detractor from the unimproved voice-controlled music synthesizer, due to the frustration of the user not being able to reach certain notes he desires to play.
In a related area, the concept of "music-minus-one" is the use of a predefined usually prerecorded musical background to supply contextual music around which a musician/user sings or plays an instrument, usually the lead part. This concept allows the user to make fuller sounding music, by playing a key part, but having the other parts played by other musicians. Benefits to such an experience include greater entertainment value, practice value and an outlet for creative expression.
SUMMARY DESCRIPTION OF THE INVENTION
The invention disclosed herein is an enhancement on the music minus-one concept, providing a degree of intelligence to the musical instrument playing the lead the voice-controlled music synthesizer, in this case so as not to produce a note which sounds dissonant or discordant relative to the background music. In addition, this invention is an improvement on the voice-controlled music synthesizer, by employing correction, but in such a way that the device can be used and enjoyed by all parties. Rather than correcting the interval in an arbitrary manner, as suggested in the Tsunoo and Ishikawa patents, this device adjusts the output of the music synthesizer to one which necessarily sounds good, to the average listener, relative to predefined background music. The key advantage of this invention is that it allows any person with speaking ability to be able to express himself/herself musically and sound good doing it, with virtually no training. Such a device can provide useful entertainment and/or creative expression value to a large number of people. In addition, it can help people learn to improvise and play music "by ear".
The entertainment and creative expression device disclosed in this application is comprised of pitch extraction means for determining pitch from a sound source, a means for storing and transmitting background music information, such as note pitches and intervals and background instruments selected, a means for storing and transmitting relevant allowable, or pleasant sounding, lead tone and harmony tone data associated with the background music, a means for using the associated filter data to translate the tone determined from the pitch extraction means raw frequency or pitch data extracted from the source tone to a tone determined to be allowable as defined in the associated filter data, music synthesizer means for musically synthesizing the output tones from the output tone data, and a means for synthesizing, transmitting, or reproducing the background music from the background music data.
Other objects, features and advantages will be made clear from the following description of embodiments thereof considered together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of an embodiment of the voice controlled entertainment device for easily playing along to background music, made in accordance with this invention;
FIG. 2 illustrates three examples of filter schema "filter tables" of varying degrees of correction;
FIG. 3 illustrates some of the options regarding changing of the filter schema or tables during or between musical sequences songs;
FIG. 4 pictorially illustrates one of the preferred embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a Source Tone 100 is received by the entertainment and creative expression device disclosed herein. The sound source can be single or multiple tones produced by a human voice singing voicing or not voicing words, humming, whistling, talking, using any single syllable such as "doo, doo, doo" or "lah, lah, lah" at varied pitches, or multiple syllables at varied pitches, or any audio apparatus which can produce tones, such as acoustic or electric or electronic musical instruments, for example, recorders, whistles, trumpets, electric guitars and the like. Each "tone" contains a fundamental frequency identifying a pitch together with a start time and duration. A sequence of pitch, start time and duration data defines a "tone sequence", "tune", "musical sequence", or "song" these terms are used interchangeably.
The introduction of the tone into the device can be either through a built-in microphone 101, external microphone, or specialized audio sensing device, such as a guitar "pick-up". For purposes of this application, the term "microphone" represents all such devices. The source tones which are introduced into the device through the microphone 101 are the basis for controlling musical tones which emerge from the device which will sound pleasing relative to predefined background music.
The input signal which is detected by the microphone 101 is analyzed by the pitch extractor 102 to determine at least the fundamental frequency or pitch of the source tone. A variety of approaches exist to detect fundamental frequencies from analog signals. One such approach is described in U.S. Pat. No. 4,202,237, dated May 13, 1980, by Bjarne C. Hakansson. Hakansson's invention extracts a fundamental frequency from signals coming from played musical instruments. Another such approach is described in U.S. Pat. No. 4,457,203, dated July 3, 1984, by Schoenberg et al. Schoenberg's patent describes a device which can automatically detect and display the fundamental frequency from sound sources with continuous frequency ranges such as the human voice.
The device's input or source tone 100, associated output tone, and associated tone-in-process at any stage within the device, are referred to herein as the "lead". The lead can be any tone or sequence of tones which the user desires, including the user's idea of a melody associated with the respective background music, the actual melody associated with the background music, a harmony associated with the background music, or a sequence totally unassociated with the intent of the author of the musical piece comprising the background music. The output tone associated with the lead is referred to as the "output lead tone" 116.
In addition to being able to generate an output lead tone 116 from the respective source tone 100, the invention optionally generates another output tone associated with the output lead tone 116 and the output background tones 115--analog tones of the background music called, in this application, an output harmony tone or tones 117. The output harmony tone is an output tone which appears to "follow" or "harmonize" with the lead tone, in such a way as to sound pleasant relative to the output background tones 115.
The memory means 105--"musical sequence data" or "song data" for the background music, along with which the user is playing the lead, contains the background music data 103 and the associated filter data 104. The musical sequence data is a necessary component of he invention. The background music data 103 can be any sequence of single or multiple notes which creates a context of musical information along with which the device's user can play a lead. The tone sequences can form recognizable songs, or parts of songs, generic patterns of tone sequences associated with certain musical styles, such as rock, folk, blues, jazz, reggae, country, and classical, or any other sequence or sequences of tones. The sound types used to play these note sequences can be pitched or nonpitched, having timbres or sound personalities associated with traditional musical instruments, electrical musical instruments, electronic or synthesized musical instruments, known or unknown sound effects, or any other type or types of sounds. For purposes of this specification, these tone sequences are referred to as "background music" or "background music data".
The media which is used to store the musical sequence data in 105 can be read-only-memory ROM circuits, or related circuits, such as EPROMs, EEROMs, and PROMs; optical storage media, such as videodiscs, compact discs CD ROMs, CD-I discs, or other, and film; bar-code on paper or other hard media; magnetic media such as floppy disks of any size, hard disks, magnetic tape; audio tape cassette or otherwise; phonograph records; or any other media which can store digital or analog song data or songs, or a hybrid of analog and digital song data or songs; or any combination of media above. The medium or media can be local, or resident in the embodiment of the device, or remote, or separately housed from the embodiment of the device.
The associated filter data 104 must necessarily be used by the device, either directly read from the storage media, or after any processing inside, or outside the device, to establish relevant allowable output tones from the source tones.
The musical sequence data storage means 105 communicates the associated filter data 104 to a tone filter 107 which accepts at least the raw frequency or pitch data 106 from the pitch extractor 102 and translates the raw frequency or pitch data 106 and any other relevant tone data to relevant allowable output tone data 108 in accordance with the associated filter data 104 predefined for the background musical sequence 103 being played. The allowable output tone data will include, at the minimum, data regarding the output lead tone 116, and may optionally include data regarding the output harmony tone or tones 117. The output harmony data can be data describing one, two, or more tones generated simultaneously. Both output lead data and output harmony data is determined by the tone filter 107 which utilizes the filter data 104 associated with the background musical data 103 to analyze and process the raw frequency or pitch data 108 from the pitch extractor 102. Examples of implementation means for translating the raw frequency or pitch information 106 into output tone data 108 are illustrated in FIG. 2 and FIG. 3, and described in detail later in this specification.
The output tone data 108, at least the output lead tone data, and optionally the output harmony tone data is then transmitted to a music synthesizer and converted to analog musical output tones 112 synthesizing musical instruments of known timbre, timbre which is similar to known timbres, or unknown timbre, or sound effects, in accordance with the defined output tone data. The user may either be allowed to define which timbre to choose for the output tone or tones, or the musical sequence data 105 will specify the appropriate timbre or timbres, or the device will be implemented so as not to offer a choice to the user as to timbre for the output tone or tones.
One implementation of the invention has the output tone data transmitted to an external interface 111 which allows the information to be used to drive an external music synthesizer, and/or to be transmitted to an external sequencer or recording device, computer, printer, another voice-controlled entertainment and creative expression device such as that disclosed herein, or any other external device for accepting and/or processing the output tone data. The interface may be an accepted standard, such as RS-232 or MIDI Musical Instrument Digital Interface, or any other communicating or interface means.
Concurrent with the transmission of the output tone data 108 to the music synthesizer 110, the background musical data 103 is transmitted to a music synthesizer (either the same 110 as that used to generate the analog musical output tones 112 or a different one) and converted to analog musical output tones 112 synthesizing musical instruments of known timbre, timbre which is similar to known timbres, or unknown timbre, or sound effects, in accordance with the defined background music data, or transmitted to an external interface 109 similar to 111, or transmitted to another musical player, such as a phonograph, radio, stereo, tape player, compact disc player, videodisc player, video tape player or any other sound generating device. The user may either be allowed to define which timbres to choose for the output tones or the musical sequence data 105 will choose the appropriate timbres, or, in some low cost embodiments the device can be implemented so as not to have a choice as to timbre.
The analog musical output tones are transmitted to the user through output means 105 such as speaker, headphones, display, external amplifier and associated speaker, or any other audio transmission means.
FIG. 2 illustrates three examples of filter schema 107 employed at any discrete point in time during the operation of the entertainment and creative expression device disclosed herein. For these examples, the source tone introduced into the entertainment and creative expression device is a whole note which has a pitch 202 squarely on a D note of any octave, and therefore, the tone's raw pitch 106 detected by the pitch extractor 102 is that of a D. The examples show the use of "the key of A" 200, as represented by three sharps 201 as illustrated on the musical staffs in FIG. 2, as the filter's reference scale, and illustrates three degrees of correction or conversely three degrees of freedom which can be employed using the scale in the key of A. These examples are the "diatonic scale filter" 203, the "pentatonic scale filter" 206, and the "melody filter" 208, in order of decreasing degrees of freedom, or increasing degrees of correction, respectively.
In the diatonic scale filter example 203, the allowable tones are the seven notes 204 at any octave of the A major scale, or the notes A, B, C♯, D, E, F♯, and G♯ illustrated in FIG. 2 by showing the whole notes in the scale as open or clear in the center 209. Not allowed would be all tones with pitches between notes in the A major scale. Since the pitch of the source tone is D 202, the output lead tone data will include the pitch designation of D 205, implementing no pitch correction on the source tone.
In the pentatonic scale filter example 206, the allowable tones are the five illustrated notes A, B, C♯, E, and F♯ open whole notes 209 on the staff in 206. The tones in the scale which are not allowed are D and G♯ closed whole notes 210 on the staff in 206. Also not allowed are all tones with pitches between notes in the A major scale. Since the pitch of the source tone in this example is D, the pitch will be corrected by the tone filter to become the closest tone in the allowable tone set, which in this case is C♯ 207.
In the melody filter 208 example, the allowable tones are limited to the single note at all octaves which is designated as the singular lead tone intended for that point in the musical sequence, wherein named the melody tone. In this example, the filter schema and musical sequence data define A 211 to be the allowable melody tone. Since the pitch of the source tone in this example is D, that pitch will be corrected by the tone filter, in this example to the nearest A note 211 which is three scale steps down from D.
FIG. 3 illustrates one of the key dynamic characteristics of the tone filter 107--that of changing the filter schema within or between musical sequences. FIG. 3 illustrates some of the options for changing these filter schema termed "filter tables" in the figure. The musical sequence represented by the musical staff or "sample song"--300 is displayed at the top of the figure and four options for the frequency of change of the filter tables 304 are positioned below the musical staff purposely aligned to show various possible frequencies for the change of filter tables. A change in the filter table is represented by a vertical arrow 305 pointing upward, at the relevant point in the musical sequence, as represented by the musical staff.
The filter data associated with the musical sequence can be set or changed once 302, at the beginning of the musical sequence song and remain the same throughout the song, or it may change every time there is a change in a chord 303, or it may change every measure 301 or fraction of a measure 306, or it may change every note or fraction of a note 307. These frequencies of filter table changes 302, 303, 306, 307 are some of the many options which can be employed to change the filter schema or tables. These examples represent differing degrees of sophistication of the filter schema, and thus differing costs, as well as memory requirements for the filter data 104 associated with the musical background data. The more frequent the change of filter tables, the more development time and thus associated cost required to "score" or annotated each musical sequence, and the more memory required to store the filter data.
FIG. 4 is an illustration of an example of one of the preferred embodiments of the invention. This embodiment includes a console 400 with built-in speaker 403, a microphone or pickup 405, one or more musical sequence or song ROM cartridge 401 with associated filter data, and optional connectors for outside amplification 408 or headphones 409. The cartridge for the desired musical sequence is inserted into the console. On the console, the user is offered the control 402 over which specific musical sequence to play as background if the cartridge contains more that one such musical sequence. This configuration shows four choices 402 but the embodiment could include any number of choices of songs, depending on what is determined to be economic to offer in the system's largest available or planned cartridge. Also on the console, the user is offered the control 404 over which lead instruments are used to sound the output lead tones 116. In addition, the console has master volume control 407 and a "voice guide" selection 406, the latter which enables "on" or disables "off" the tone filter 107. The purpose of this control would be to let singers choose to implement no correction to at least the pitch in the source tone. Optional, but not shown in this configuration, is a set of user controls to activate and manipulate a harmony feature as described in this application.
Although the present invention has been shown and described with respect to preferred embodiments, various changes and modifications which are obvious to a person skilled in the art ow which the invention pertains are deemed to lie within the spirit and scope of the invention. | An electronic entertainment device which allows an untrained vocalist or instrumentalist to easily synthesize an instrumental lead, and optionally, one or more harmonies, simultaneous with the lead, playing along with predefined background musical sequences. While the background parts to a song are being played by the device, or any outside musical player, the user plays the melody, or "lead", by humming, singing, whistling, or operating any tone-producing device, such as a musical instrument, into the device. The device then identifies the pitch, compares it with a table of allowable pitches, as dictated by predefined data associated with the background music, chooses an appropriate output tone, and drives a music synthesizer to play the chosen instrument at the determined pitch, in accordance with the allowable pitches. The note which is produced by the device is one which sounds pleasing in the context of the musical background. The device facilitates an active involvement in music expression without a need for well developed skills as a vocalist or instrumentalist. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic anti-skid brake system of a motor vehicle, and more particularly to a system for controlling the power train of the vehicle, when the anti-skid brake system (ABS) is in operation.
The anti-skid brake system is installed on a brake system for wheels of the vehicle. The anti-skid brake system is provided for preventing the wheels from completely locking, and hence from skidding during rapid braking or by braking on slippery surfaces such as snowy roads, thereby ensuring directional stability and steering control of the vehicle during the braking operation and improving safety of the vehicle. For example, Japanese Patent Laid Open 60-61354 discloses an anti-skid brake system where an anti-skid control unit is operated to stop a supply of brake fluid to cylinders of the wheels so as to reduce the brake fluid pressure in dependency on speed reduction rate of the wheels and on relative reduction rate of the wheels to that of the vehicle speed. When the wheel speed is increased by the reaction from the road surface to approach the vehicle speed, the brake fluid is then again supplied to the cylinders to increase the pressure. The operation is repeated so as to effectively brake the vehicle without locking the wheels.
However, on a road having little reaction or a small friction coefficient, the wheels are easily locked with a slight braking pressure. Although the anti-skid brake system is operated to reduce the fluid pressure in the cylinders, since the reaction of the road surface is small, it requires a long time for the wheels to recover their speed. Moreover, although a minimum pressure is applied after the wheel speed is recovered, braking effect is too large for the road surface to cause an excessive slipping rate which results in unstable steering of the vehicle. Such a phenomenon is aggravated when engine braking is effected on the vehicle body.
If the engine braking is effected in the anti-skid operation, the engine braking force is exerted on the wheels to lock them in spite of the anti-skid operation. Since the anti-skid brake system operates to reduce the fluid pressure in the system in accordance with the deceleration of the wheel speed, if the wheel speed is disturbed by the engine braking, the efficiency of the anti-skid brake system is reduced. Thus, it is desired to eliminate the disturbance due to the operation of the engine braking, for providing a proper anti-skid brake system control.
In order to eliminate the disturbances, there has been proposed a system where a transmission control unit is provided in the anti-skid brake system to disconnect a clutch provided in the power train between a transmission of the vehicle and the wheels. Namely the power transmitting system from the engine to the wheels is disconnected when the anti-skid brake system is operated. The disconnection of the transmitting system, where the engine braking does not act, continues as long as the anti-skid brake system operates. However, exclusive terminals for operating the transmission control unit must be provided on the anti-skid control unit. Accordingly, a conventional anti-skid brake system can not be used.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a system for controlling a clutch for transmitting engine power to vehicle wheels when the anti-skid brake system is operated, without providing exclusive terminals on an anti-skid control unit.
According to the present invention, there is provided a power transmission control system for a motor vehicle having an anti-skid brake system, the vehicle having a clutch for transmitting power of an engine to either of front or rear wheels, the system comprising a brake switch closed by depressing a brake pedal of the vehicle to produce a brake signal, detector means for detecting operation of the anti-skid brake system and for producing an anti-skid signal, and releasing means responsive to the brake signal and to the anti-skid signal for releasing the clutch to eliminate a disturbance of the vehicle speed due to the operation of the engine braking so as to provide a proper anti-skid brake system control.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram showing a power transmission system of a four-wheel drive vehicle to which the present invention is applied;
FIG. 2 is a schematic block diagram showing a brake system according to the present invention;
FIG. 3 shows an electric circuit in the brake system;
FIG. 4 is a flow chart showing the operation of the system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 showing a power transmission system for a four-wheel drive vehicle, an internal combustion engine 1 is mounted on a front portion of the vehicle. The engine 1 is operatively connected with an automatic transmission 3 through a torque converter 2. The automatic transmission 3 is further connected to a transfer device 4 comprising a multiple-disk transfer clutch 5 operated by a solenoid valve 5a (FIG. 3). The output of the automatic transmission 3 is transmitted to a front drive shaft 6, through the transfer device 4. The front drive shaft 6 is connected with front wheels 8 through a front differential 7. The output of automatic transmission 3 is further transmitted to a rear drive shaft 9 through the multiple-disk transfer clutch 5 and a rear differential 10 so as to drive rear wheels 11.
Referring to FIG. 2 showing a brake system for the front and rear wheels having an anti-skid brake system as an electronic brake control system, a brake pedal 12 is connected to a master cylinder 13 for producing a fluid pressure in accordance with the depression of the brake pedal 12. The master cylinder 13 is communicated with a modulator 17 of the anti-skid brake system. The modulator 17 is communicated with brake devices 14 of the wheels 8 and 11 (only one of the wheels is shown in FIG. 2). A wheel speed sensor 16 is provided adjacent each wheel and produces a wheel speed signal which is applied to an anti-skid control unit 20 of the anti-skid brake system. An output signal of the control unit 20 is applied to the modulator 17. The modulator 17 has a motor pump 23 (FIG. 3) and various valves (not shown) for reducing and for increasing and holding the pressure, so as to control the brake fluid pressure when the anti-skid brake system is in operation. The system further has a normally open brake pedal switch 15 which is closed by depressing the brake pedal 12 and connected to the control unit 20. A transmission control unit 18 is provided in the system for applying a duty ratio signal to the solenoid valve 5a to disengage the transfer clutch 5.
Referring to FIG. 3 showing an electric circuit for the brake system, the anti-skid control unit 20 comprises a CPU (central processing unit) 21 which is applied with signals from the brake pedal switch 15 and the wheel speed sensor 16 representing the wheel speed.
The CPU 21 is connected to a base of a transistor 22, an emitter of which is grounded. A collector of the transistor 22 is connected through a terminal 28 with a relay coil 24a of a relay 24 provided in the modulator 17. The coil 24a is connected to a power source B through an ignition switch IGN. The CPU 21 produces an output signal Sm which is fed to the base of the transistor 22 to render it conductive. Thus, the coil 24a is energized to close a contact 24b, thereby connecting the motor pump 23 with power source B. The terminal 28 is further connected to one of a pair of input terminals of a comparator 25 in the transmission control unit 18. The other input terminal of the comparator 25 is applied with a reference voltage. An output of the comparator 25 is applied to an input terminal T1 of a CPU 26. When the input terminal T1 is at a low level, the coil 24a is energized to close the contact 24b so as to operate the motor pump 23. This means that the anti-skid brake system is in operation. Another input terminal T2 of the CPU 26 is applied with a brake signal Sb from the brake pedal switch 15. When the brake pedal 12 is depressed to close the brake pedal switch 15, the input terminal T2 is at a high level. The CPU 26 produces a duty signal to the solenoid valve 5a of the transfer clutch 5 when terminal T1 is at the low level and terminal T2 is at the high level. A stop lamp 19 is further provided in the circuit so as to be turned on when the brake pedal switch 15 is closed.
When the brake pedal 12 is depressed, the master cylinder 13 produces the brake fluid pressure which is supplied to the brake device 14 to brake the wheels 8 and 11. When the reduction rate of the wheel speed by the braking exceeds a predetermined value, the CPU 21 of the anti-skid control unit 20 produces a high level output Sm to render the transistor 22 conductive. Accordingly, relay coil 24a is excited, thereby closing the contact 24b of the relay 24. Thus, the motor pump 23 is driven to operate the anti-skid brake system so as to maintain and to reduce the fluid pressure in the brake device 14. Accordingly, the wheel speed reduction rate decreases and increases alternately until the wheel speed approaches the vehicle speed. Thereafter, the pressure to brake the wheels is increased. By repeating the operation, the locking of the wheels can be prevented.
Even though brake pedal 12 is released, the anti-skid brake system may be operated when the wheel speed does not approach the vehicle speed.
While the transistor 22 is conductive, the terminal 28 is at the low level, so that a low level signal SM is applied to the terminal of the comparator 25. The level of the other input terminal of the comparator 25 is at a high level. Thus, the comparator 25 applies a low level output signal to the terminal T1 of the CPU 26. On the other hand, when the brake pedal 12 is depressed to close the brake pedal switch 15, the high level output signal is applied to the other terminal T2. Accordingly, the CPU 26 produces a duty ratio signal which is applied to the solenoid valve 5a to disengage the clutch 5. Thus, the rear drive shaft 9 is disconnected from the transmission 3, thereby reducing the engine braking effect on the vehicle body. Therefore, the anti-skid brake system is sufficiently operated without being affected by the engine brake.
Referring to FIG. 4 describing the operation for cutting the transmission of power to the rear wheels, it is determined whether the anti-skid brake system is operating depending on the level of the signal SM. When the anti-skid brake system is operated, that is when the level of terminal T1 is at a low level, it is further determined whether the brake pedal switch 15 is closed. When the brake switch is closed, that is when the terminal T2 has a high potential, the power transmission system is in an anti-skid brake mode, namely the transfer clutch 5 is disengaged.
The present invention may be applied to a four-wheel drive vehicle having a transfer clutch, the capacity of which is changeable. In such a transmission system, the distribution ratio to the rear wheels is decreased instead of entirely cutting off the transmission in the anti-skid brake mode. The present invention may be further modified so as to be applied to a vehicle having an automatic transmission with an auxiliary speed range.
From the foregoing, it will be understood that the present invention provides a system applied to an anti-skid brake system for preventing the locking of the wheels on roads having a low friction coefficient while the anti-skid system is working. The system can be realized by a slight modification of the conventional anti-skid system without providing exclusive terminals.
While the presently preferred embodiments of the present invention have been shown and described, it is to be understood that this disclosure is for the purpose of illustration and that various changes and modifications may be made without departing from the scope of the invention as set forth in the appended claims. | A clutch is provided for transmitting power of an engine to either of the front or rear wheels of a motor vehicle. A brake switch is provided to be closed by depressing a brake pedal of the vehicle to produce a brake pedal, and a detector is provided for detecting operation of an anti-skid brake system and for producing an anti-skid signal. In response to the brake signal and to the anti-skid signal, the clutch is disengaged, thereby reducing engine braking effect. | 1 |
RELATED APPLICATION DATA
Claim to Priority
This application claims priority from U.S. Provisional Patent Application Ser. No. 61/299,547 entitled “Coupling Member” filed Jan. 29, 2010 and is incorporated by reference herein.
FIELD OF THE INVENTION
The present invention relates to coupling mechanisms for oil and gas processes and related apparatuses. More specifically the present application discloses an invention which is employed for coupling communication lines and other apparatuses which pertain to riser joints and those which allow control of blowout preventers (“BOP”) and other related wellhead control devices.
BACKGROUND OF THE INVENTION
Currently mechanisms which bind various well control lines to drill strings fall short of effectively coupling components which are used in drilling and production of oil, gas, and other minerals. Components which supply communication to various portions of BOPs, well heads, subsea production trees, and associated members often do so through communication lines which supply fluid, pressure, electronic communication, and allow for physical manipulation of the BOP, well head, subsea production tree and associated tools. Unfortunately, communication lines inadequately couple to components which are run subsea. When communication lines are inadequately coupled to the riser string, the various components are at risk of being damaged and are rendered inoperable.
In an underwater drilling rig riser, multiple lines are integrated in the rig riser. These include multiplexed (MUX) hydraulic lines, choke lines, boost lines, an Installation/Workover Control Systems (IWOCS) line, and other umbilical lines. In conventional installations, the failure of a riser or its release from the subsea installation due to tripping of a blowout preventer cuts these various lines as they are integrated in the riser. The present invention presents an improved riser clamp to securely hold the various lines in place typically as a retrofit as well as allowing for the selective release of the all important IWOCS line away from the riser for easy replacement or continued control of the subsurface wellhead assembly.
Presently numerous coupling mechanisms fail to appropriately couple communication lines and allow for interference from physical damage, and sometimes even sea life in subsea applications. In certain instances, movement of communication lines and drill string through subsea currents are believed to attract aquatic life, and from time to time have been retrieved with bite marks.
Sometimes, communication lines are attached to various segments of a riser. When a riser and various pipes are lowered and raised from drilling and/or work-over rigs a coupling mechanism is mounted to riser joints at inappropriate locations which causes extra pauses during the runs to attached said lines and therefore increasing the deployment times dramatically. Then, a communication line is subsequently coupled to the coupling mechanism. This is somewhat problematic, due to rig day-rate costs and auxiliary services employed in drilling and servicing oil wells.
Floatation (Buoyancy) is fitted to the riser in deepwater drilling to reduce the overall weight of the riser string and allow deployment of such in a reasonable manner. In some cases “cutouts” or cavities are provided in the floatation to allow for the mounting of the control cable clamps at an appropriate location so that the cables/hoses can be attached in conjunction with the addition of the next joint of riser, but this is not always the case. Where the floatation is not supplied with this feature the clamps have to be fitted either above or below the floatation which adds an extra stopping point for each joint during the run, thus adding an inordinate amount of time to the riser run. The design of this clamp allows the positioning of the clamp along the full length of the joint without the need of a cutout or a cavity. This allows the positioning of the clamp to be coordinated with the landing point of each joint so that the cables/hoses can be attached simultaneously with the adding of the next joint of riser thus greatly reducing the run time of the riser.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the invention there is shown a clamp for placement about a riser having an assembly with a housing for releasably engaging at least one strap, the strap having a first and second end wherein the first and second ends are releasably attached to the housing, a plate on the housing for selectively engaging the first and second ends of the strap, and a support operably connected to the housing for releasably holding at least one cable.
In accordance with another preferred embodiment of the invention there is shown a clamp for placement about a riser having an assembly with a housing for releasably engaging at least one generally circular member, the circular member having a male protrusion to engage a rotating shaft in said housing, and a support operably connected to the housing for releasably holding at least one cable.
In accordance with another preferred embodiment of the invention there is shown a clamp for placement about a riser having an assembly with a housing for releasably engaging at least one generally circular strap, a mount in said housing for selectively engaging said strap; and a support operably connected to said housing for releasably holding at least one cable.
Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
FIG. 1 shows a perspective view of an assembly of a preferred embodiment of the present invention.
FIG. 2A shows a perspective view of a portion of the assembly of a preferred embodiment of the present invention.
FIG. 2B shows an alternative perspective view of a portion of the assembly of a preferred embodiment of the present invention.
FIG. 3 shows another perspective view of a portion of the assembly of a preferred embodiment of the present invention.
FIG. 4 shows an overhead perspective view of the assembly of a preferred embodiment of the present invention.
FIG. 5 shows a perspective view of an alternative preferred embodiment of the present invention.
FIG. 6 shows another perspective view of an alternative preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 , a perspective view of a preferred embodiment of the present application is illustrated. A coupling member 10 includes strapping assembly 20 , communication grasp 30 , and swivel assembly 42 for assisting in coupling a communication member (not shown) by communication grasp 30 . In a preferred embodiment of the present application strapping assembly 20 includes opposing straps 20 a and 20 b that align substantially parallel to one another and are disposed to circumferentially surround another member such as a drill string or pipe component. Straps 20 a and 20 b may be of any of a variety of materials including composite, rubber, synthetic, or metallic. Strapping assembly 20 includes a bracket member 22 for coupling one or more straps 20 a and 20 b . Bracket member 22 includes receiving portions for drawing tension via straps 20 a and 20 b . Bracket member 22 includes grooves for adapting one or more straps 20 a and 20 b.
Communication grasp 30 couples to bracket member 22 and is fashioned to receive one or more communication lines. Communication grasp 30 includes a clamping portion 32 that includes channels 34 a and 34 b . Clamping portion 32 includes a hinging apparatus 36 for allowing communication lines having various diameters to be adapted to coupling member 10 . Components of clamping portion 32 are adapted to receive swivel assembly 42 . Swivel assembly 42 includes a first swivel member 40 and a second swivel member 44 . Swivel member 44 is optionally spring loaded to apply tension and couple communication lines about channels 34 a and 34 b of communication grasp 30 .
In one mode of operation, straps 20 a and 20 b remain in an open position about strapping assembly 20 . Coupling member 10 is adapted about a substantially circumferential body. Straps 20 a and 20 b are then drawn around a substantially circumferential body in tension via strapping assembly 20 and optionally pulled or ratcheted to create additional tension about a substantially circumferential body. Communication lines are secured about communication grasp 30 . Communication grasp 30 receives communication lines via channels 34 a and 34 b . Swivel assembly 42 is positioned to allow for containment of communication lines. Once communication lines are disposed within channels 34 a and 34 b , swivel member 40 is pivoted towards swivel assembly 42 . Swivel member 40 is subsequently secured against swivel assembly 42 , via swivel member 44 . In an instance in which communication lines are not aligned with the direction of a substantially circumferential body, strapping assembly 20 and swivel assembly 42 are allowed to pivot about one another while securing communication lines and a substantially circumferential body. In the event that strapping assembly 20 and swivel assembly 42 need to be immediately separated from one another, in certain embodiments, their coupling methodology may allow for the severance of each component.
Referring now to FIG. 2 a , a view of a strapping assembly 20 is illustrated. As is shown, strapping assembly 20 is illustrated having strap 20 a and strap 20 b in a “closed” position as if each were surrounding a circumferential component. Accordingly, set screw 21 a and set screw 21 b are positioned to retract and deploy first strap 20 a and second strap 20 b . Once strap 20 a or strap 20 b is within the confines of channels 23 a and 23 b , set screws 21 a and 21 b may be rotated, allowing tension to be drawn about straps 20 a and 20 b . Straps 20 a and 20 b may be fitted with a grommet on each of the strap that engages screws 21 a and 21 b for selective movement of the strap thereby tightening and loosening the straps about the riser. Alternatively, straps 20 a and 20 b may have one end that is fixed to strapping assembly 20 and a second end that is fitted with a grommet for engagement to screws 21 a or 21 b . In the event that it is desirable to draw tension about strap 20 a and 20 b , set screws 21 a and 21 b may be rotated in order to draw straps 20 a and 20 b within the confines of channels 23 a and 23 b to tighten the strap about the riser. In the event that it is desirable to partially or fully release tension from straps 20 a and 20 b , from the confines of channels 23 a and 23 b , set screws 21 a and 21 b may be rotated to allow tension to be released from the detent in which each screw is selectively disposed. Screws 21 a and 21 b may be threaded through plates 26 a and 26 b respectively so that upon engagement of said screws, the plate moves inward and outward along the shaft of the screw. By doing so, the straps are pulled inward and tightened or loosened. Plates 26 a and 26 b may be of a variety of configurations including a tapered square wedge, as shown in the inset of FIG. 2A , which facilitates locking the straps in place into a reciprocal void that may be tapered or not.
As is readily apparent to one of ordinary skill, the straps may alternatively be engaged to the housing by other means including a ratcheting mechanism that engages the plate or straps alone to pull them inward to the housing.
Strapping assembly 20 includes stabilizing members 24 a and 24 b which align about straps 20 a and 20 b . Stabilizing members 24 a and 24 b assist in aligning strapping assembly 20 both about the bottom and top of straps 20 a and 20 b . Through including stabilizing members about the bottom and top of straps 20 a and 20 b , drifting and walking of coupling member 10 is prevented when extraneous forces are exerted.
Referring now to FIG. 2 b , an alternative view of strapping assembly 20 as shown in FIG. 2 a , is illustrated. Accordingly, detents or voids 25 a and 25 b are illustrated for communicating with set screws 21 a and 21 b (not illustrated). In certain embodiments, communication grasp 30 may be separated from strapping assembly 20 to allow for manipulation of set screws 21 a and 21 b (not illustrated). Similarly, an adapting member 27 for coupling communication member 30 (not illustrated) and strapping assembly 20 is illustrated. Adapting member 27 includes indentation 28 , for preventing slippage between communication member 30 and strapping assembly 20 . Adapting member 27 also includes aperture 29 a which is disposed parallel to the longitudinal axis of communication member 30 . Adapting member 27 also includes aperture 29 b , which is disposed normal to the longitudinal axis of communication member 30 . Insert (not pictured) may be disposed within apertures 29 a and 29 b in order to allow removable coupling of communication grasp 30 and strapping assembly 20 .
Referring now to FIG. 3 , a view of communication grasp 30 is illustrated. As is illustrated, communication grasp 30 , includes a receiving aperture 31 for allowing coupling of strapping assembly 20 via adapting member 27 (shown in FIG. 2 b ). When strapping assembly 20 couples to communication grasp 30 , indentation 28 (shown in FIG. 2 b ) mates with ridge 33 . Ridge 33 allows for a slip fitting of communication grasp 30 and strapping assembly 20 . Once communication grasp 30 and strapping assembly 20 fully abut one another, a securing pin (not shown) may be inserted into aperture 29 b , while locking pin 35 may be disposed within aperture 29 a (shown in FIG. 2 b ) to securely couple strapping assembly 20 and communication grasp 30 .
Referring now to FIG. 4 , an alternative view of coupling member 10 is illustrated. As is shown, communication grasp 30 includes parallel channels which are substantially cylindrical and hollow. Channel 34 a incorporates a slightly smaller diameter than channel 34 b . Swivel assembly 42 secures communication and other lines (not pictured) via swivel member 44 and swivel member 40 through coupling components of hinging apparatus 36 in a substantially perpendicular manner. Strapping assembly 20 as well as straps 20 a and 20 b along with channels 34 a and 34 b are all substantially aligned. When swivel assembly 42 secures communication lines via hinging apparatus 36 in the depicted orientation, each of the communication lines align the substantially perpendicular to the longitudinal orientation of swivel assembly 42 .
Turning now to FIG. 5 , there is shown a perspective view of an alternative assembly according to a preferred embodiment of the present invention. Assembly 60 has clamp base 88 which is operably connectable to clamp assembly 63 and 65 . Clamp assembly 63 has side clamp 66 in hinged connection to side clamp 68 . Side clamp 66 has hinge section 74 that mates with side clamp 68 at hinge section 72 . Hinge sections 72 and 74 have reciprocal interleaved members but any of a variety of hinge mechanism may be employed. Pin 70 is inserted into hinge sections 72 and 74 thereby making a flexible hinge joint.
Side section 66 has end section 99 that mates with end section 97 of side section 68 to form a male insert 100 for operable engagement to clamp base 88 . Male section 100 has a threaded opening 90 for insertion of screw 96 through aperture 92 into opening 90 . Screw 96 is inserted into lock washer 94 and tightened into opening 90 thereby drawing clamp assembly 63 into stable engagement to clamp base 88 . Pads 76 and 77 and 80 and 82 , are positioned on the inside circumference of clamp assemblies 63 and 65 respectively to provide cushioned support for the clamp when it is positioned around the riser. Alternatively, clamp assembly 63 could be configured of a single flexible piece of material in a circular configuration with end sections 97 and 99 mating to form male insert 100 and still have the same ability for stable engagement to clamp base 88 .
Male inserts 100 and 101 are preferably configured with a tapered outer dimension so that upon engagement by screws 96 and 98 , each wedges into clamp base 88 . As shown in FIG. 6 , male insert 100 is inserted into void 104 upon engagement of clamp assembly 63 being drawn into void 104 upon activation of screw 96 . As is readily apparent, a tapered shape to male insert 100 provide stable engagement with void 104 when fully inserted. Void 104 may be preferably tapered in a reciprocal manner to facilitate stable engagement to male insert 100 . Similarly, clamp assembly 65 is inserted into void 106 by male insert 101 and stably engaged.
Clamp assemblies 63 and 65 may be composed of a variety of materials including composite, rubber, synthetic, or metallic.
Assembly 60 as shown in FIGS. 5 and 6 may be connected in similar fashion as previously described to communication grasp 30 for holding various lines including multiplexed (MUX) hydraulic lines, choke lines, boost lines, an Installation/Workover Control Systems (IWOCS) line, and other umbilical lines.
It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims.
All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the structures and methods of this invention have been described in terms of various embodiments, it will be apparent to those of skill in the art that other variations can be applied to the structures and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. | A clamp for placement about a riser having an assembly with a housing for releasably engaging at least one strap, the strap having a first and second end wherein the first and second ends are releasably attached to the housing, a plate on the housing for selectively engaging the first and second ends of the strap; and a support operably connected to the housing for releasably holding MUX, IWOC and other umbilical cables used in subsea applications. The housing may have two straps for engagement to a riser that shorten and lengthen by the turning of a screw through a plate engaged to the straps. The clamp may also have a hinged or fixed circular member for attachment around the riser. The cables are held by a hinged attachment to the housing that forms cylindrical vertical openings upon closure of the hinge. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to a lockwire system for header bolts. More specifically the invention is intended for use in assemblies that are susceptible to loosening due to vibration or other forces. The invention includes a bolt with at least one hole drilled through the head of the bolt and a lockwire that is placed through two bolts. A coiled wire is also provided to keep the lockwire in position in the holes in the heads of the bolts.
BACKGROUND OF THE INVENTION
[0002] Various methods have been used in the past to prevent or reduce the possibility that a nut or bolt will loosen or back out due to vibrations. Methods of this type include castle nuts, thin safety wire, cotter pins, hairpins and Nylock nuts or bolts.
[0003] One common method of reducing the rotation of a bolt is with the use of safety wire such as shown in FIG. 1 . Safety wire is used with drilled bolts, and a thin wire that is placed through the heads of bolt and then twisted using a special tool and connected to either other bolts or to an anchor to prevent the bolt from loosening. While this method locks bolts from loosening, it is installed using special safety wire pliers, and in order to remove the safety wire, the wire is usually cut. The installation is usually arduous, and requires special equipment.
[0004] C. M Rice U.S. Pat. No. 2,758,628 discloses a Bolt and Nut Rotation Restraining Means consisting of a special clip member retainer that fits over a bolt. A wire is placed through the special clip member to prevent the bolt from backing out. This patent is most specifically designed for use with the nuts on the wheels of an automobile. While this patent discloses a method of preventing the loosening of bolts, it requires special clip members that are placed around the bolt pattern. Because the safety wire does not go through an anchor location the bolt retaining means can loosen off of all the bolts, and the entire bolt retaining means can fall off as a set.
[0005] James R. Quales U.S. Pat. No. 4,298,299 discloses a cotter pin that is placed through the end of a smooth shaft or nut. The cotter pin is easily installed and removed. While the cotter pin can be placed through a bolt and nut to prevent the nut from loosening on the bolt, it requires that a hole be drilled through both the nut and the bolt, and that the holes be aligned in order to place the wire through the nut and bolt.
[0006] Anthony U.S. Pat. No. 4,893,975 discloses a locking device for engagement onto bolt heads consisting of a special locking plate that fits over a bolt. A wire is placed through the special locking plate member to prevent the bolt from backing out. This patent is most specifically designed for use with the nuts on an aircraft engine. While this patent discloses a method of preventing the loosening of bolts, it requires special locking plate members that are placed over the bolts. A safety wire is then placed through the head of the bolt to prevent the locking plate from sliding off the bolt head(s). The invention uses multiple safety wires that go through two bolts and also a separate locking plate that adds complexity and expense to the assembly.
[0007] What is needed is a simple method to install and remove lockwire for header bolts that can be installed without requiring special tooling. The ideal device would be packaged in a single kit containing multiple sets of drilled bolts, lockwire and retainer coils to prevent the possibility that the bolts will not back-out. The proposed application satisfies these requirements.
BRIEF SUMMARY OF THE INVENTION
[0008] It is an object of the lockwire to provide a bolt retention mechanism that prevents a bolt from loosening. The loosening can be caused by vibration or thermal expansion and contraction.
[0009] It is another object to provide bolts with holes that are pre-drilled through the flats of the bolt. The pre-drilled holes can accept a lockwire to prevent the possibility that the bolt will loosen while it is installed in an automotive application.
[0010] It is another object of the lockwire components to provide pre-drilled bolts that are heat-treated to allow for higher torque capability of the bolts when they are installed in an automobile or other application.
[0011] It is another object of the lockwire to provide a lockwire that is easy to install and remove without requiring the use of special tools.
[0012] It is another object the lockwire to provide a lockwire with a helical retaining mechanism that prevents the lockwire from falling out of the bolts that are retained by the lockwire.
[0013] It is another object of the lock wire kit to provide bolts that include both a hexagonal head for use with a conventional socket wrench or open-end wrench. An installation tool is provide with a hex or Allen drive socket for ease of installation where the Allen head socket is used to start the bolt, and the external hexagonal head is used to torque the bolt to the desired setting prior to the installation of the lockwire.
[0014] It is another object of the lockwire to provide a lockwire that can be formed or deformed for placement through the holes of the bolts, after the bolts are torqued to the desired setting. The lockwire is placed through the helical coil and then placed through the holes in the heads of the bolts and remain in place.
[0015] It is another object of the lockwire kit to provide an installation tool that is compatible for use with a standard socket wrench on one end and a multi-position Allen key wrench on the other. The Allen key wrench is used in combination with the socket wrench and the lock wire bolt to start and drive the bolt into a threaded hole.
[0016] It is still another object of the lockwire to provide a kit of multiple drilled bolts, multiple lockwire, multiple helical retaining coils and an installation all in one kit to allow a user to install the lockwire without the need to purchase the components separately.
[0017] Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is various prior art methods of using a wrapped lockwire.
[0019] FIG. 2 is two views of the preferred embodiment of the drilled bolt.
[0020] FIG. 3 is a view of lockwire as installed in the preferred embodiment.
[0021] FIG. 4 is a view showing the included installation tool.
[0022] FIG. 5 is a view of the packaged lockwire.
DESCRIPTION
[0023] Refer first to FIG. 1 that shows various prior art methods of using a wrapped safety wire. This figure shows three views of a common method of securing nuts 10 with safety wire 12 . The view on the left shows two nuts being secured. The view on the right shows three nuts being secured. The middle view shows the safety wire wrapped on multiple bolts as it might be installed on a manifold 15 . This type of safety wire installation involves using drilled head bolts, and passing a thin flexible wire through the head of each bolt. After the wire is passed through the head of each bolt, the ends of the wire are brought together and a special safety wire tool is incorporated to twist 11 the wires together. The process of passing the ends of the wire through each bolt and twisting the free ends is continued until all the bolts have been secured and the ends of the wire are twisted together 13 .
[0024] FIG. 2 shows two views of the preferred embodiment of the drilled bolt. The bolt 20 is constructed in a similar method that a standard hex bolt is manufactured. In the preferred embodiment, the bolt is a high torque rated heat-treated steel bolt. Other materials for the bolt are contemplated and include but are not limited to aluminum, copper, brass, stainless steel, plastics, or combination thereof. A bolt is shown as the preferred embodiment, but the threaded fastener may be a screw or nut that has at least one hole drilled through the head, flat or side of the fastener and a wire can be passed through the hole. In the preferred embodiment the bolt is constructed with a hexagonal shaped head 24 . The head has holes drilled 22 or fabricated perpendicular to the flats on the sides of the head. In the preferred embodiment a hole goes through each of the six flat side of the bolt. The drilled hole(s) can be in a range from 0.050 to 0.100. In the preferred embodiment the hole is nominally 0.076 inches in diameter. The bolt is also constructed with a flange 26 or integrated washer to eliminate the need for an additional washer and or to distribute the load from the bolt to larger area. A threaded area 28 exists on the side opposite the head of the bolt. The threaded area is for engagement in the hole where the bolt will be threaded in. In the embodiment shown the entire length of the bolt is shown threaded, but the bolt may include a non-threaded area under the head of the bolt. Referring now to the top of the bolt, an Allen or hex head recess is provided to allow a secondary driving location to thread the bolt into the manifold. This embodiment shows the bolt with a 7/16″ external hex drive side and a 3/16″ hex internal drive side with the bolt having an overall length of ⅞ inch. While these dimensions are shown as one contemplated embodiment, other dimensions and drive configurations are possible provided a through hole can be placed through the head of the threaded fastener.
[0025] FIG. 3 shows a view of lockwire as installed in the preferred embodiment. This figure shows the bolts 40 installed on an exhaust header 95 as they may be used in an automotive application. For this type of application the header is placed onto the vehicle with any required gasket material between the header and the engine block. Once the header is brought into position the lockwire header bolts can be installed onto the engine. FIG. 4 shows one possible installation method used for this installation. In FIG. 4 the header 90 is shown with a bolt 40 . An instructional prompt 92 shows some information regarding the use of the installation tool 80 that can be used in the installation. The tool 80 consists of a driver with a ⅜″ socket fitting on one side and an Allen or hex driver on the other. The hex driver can be placed into the head of the bolt, and the bolt can be seated onto the header-mounting flange 90 . The header exhaust tube 95 is shown in this figure as it is connected to the header-mounting flange. The instruction information 92 indicates that the hex driver tool allows driving the bolt at an angle making the installation of the bolts simpler. Referring back to FIG. 3 for further clarification on the lockwire installation. After the bolts have been installed onto the header, the bolts can be torqued to the required specifications.
[0026] Once the bolts are torqued, as required, the lockwire 50 with the coiled retainer member 60 is placed into the holes 22 in the heads of each bolt until the lockwire exits the bolt on the other side of the through hole 23 . The ends of the wires are slightly bent out 51 to lock them into the bolts. The bent ends and the coiled retainer member 60 provide sufficient friction and hold to the lockwire to reduce the possibility that the lockwire will move in the drilled holes in the bolts. The lockwire is not twisted or locked onto itself, another wire, or onto another component to retain the lockwire in place.
[0027] The lockwire is fabricated from a corrosion resistant material that will not melt under the temperatures of engine. The lockwire may be fabricated from material including, but not limited to, aluminum, copper, brass, stainless steel or combination thereof. In the preferred embodiment the lockwire is made from stainless steel. The diameter of the lockwire can range from 0.02 to 0.08 inches in diameter and more preferably 0.040 to 0.060 inches in diameter. In the preferred embodiment the wire is nominally 0.046 inches in diameter or 18-gage wire.
[0028] The coiled retainer wire is fabricated from a corrosion resistant material that will not melt under the temperatures of engine. The coiled retainer may be fabricated from material including but not limited to aluminum, copper, brass, stainless steel or combination thereof. In the preferred embodiment the coiled retainer wire is made from stainless steel. The diameter of the coiled retainer wire can range from 0.01 to 0.15 inches in diameter and more preferably 0.015 to 0.050 inches in diameter. In the preferred embodiment the wire is 0.023 inches in diameter or 23-gage wire. The coiled retainer wire has an outside diameter sufficient to wrap around the lockwire to allow movement of the lockwire without allowing the lockwire to fall free through the coiled retaining wire. In the preferred embodiment the outside diameter is nominally 0.135 inches in diameter.
[0029] FIG. 5 shows a view of the packaged lockwire. This packaging method 30 shows one contemplated embodiment that the lockwire header bolts can be packaged for sale. The packaging includes at least two drilled bolts 40 , and in the packaging shown twelve bolts are included. A lockwire 50 and coiled retainer wire 60 are shown in the packaging placed through a set of drilled header bolts 51 and 53 . In this embodiment of packaging a hole 70 is used to hold the packaging on a display rack. The packaging further includes an installation tool 80 that is provided to assist in the installation of the lockwire header bolts.
[0030] Thus, specific embodiments and applications for a lockwire utilizing a lockwire with a helical retainer for the lockwire have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. | A locking device for preventing the loosening of bolts that are subject to vibration is disclosed. The locking device is a simple to install and remove lockwire section that is placed through bolts having a plurality of holes drilled through head of the bolts. The locking device further includes a spiral wrapped retainer wire that the lockwire is placed through, reducing the possibility that the lockwire will back out of the bolt head. Advantages over traditional safety wire include the elimination of twisting the wire to install and clipping the wire to remove. The lockwire device is used with sets of two bolts, and is ideally suited for automotive applications where engine vibration can loosen manifold bolts. | 5 |
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