Assemblies Of Noncircular Section Patents (Class 174/129R)
  • Patent number: 6072120
    Abstract: A top phase transmission line and bottom phase transmission line are stretched between support steel towers so that the bottom phase transmission line is positioned below the top phase transmission line. Each of the transmission lines has at least two conductors, which conductors are arranged to be substantially parallel and are separated by a substantially constant distance by interconductor spacers. An intermediate phase transmission line may be arranged between the top phase transmission line and bottom phase transmission line as well. Such transmission lines are multiconductor transmission lines. In these multiconductor transmission lines, the conductor positioned at the left side in the top phase transmission line and the conductor positioned at the right side in the intermediate phase transmission line or bottom phase transmission line directly below it are connected by a first interphase spacer made of an insulator.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: June 6, 2000
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yutaka Matsuzaki, Jun Katoh, Takeo Munakata
  • Patent number: 6042932
    Abstract: A flexible buss bar adapted for electrical connection with circuitry carried by a glass pane is provided, as well as a method of attaching a flexible buss bar to a glass pane. The flexible buss bar includes a flexible conductor having at least one metallic contact pad affixed thereto. It is also contemplated to have a plurality of such metallic contact pads attached at regular intervals along the length of the flexible conductor. The spacing of the plurality of metallic contact pads is selected to match the locations of corresponding structures formed on the glass pane. Solder cladding is selectively adhered to portions of the at least one metallic contact such that the at least one metallic contact pad may be bonded to the corresponding structure located on the glass pane.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: March 28, 2000
    Assignee: Methode Electronics, Inc.
    Inventors: Gerald Ingles, Raymond Simons, Suellyn Collins, Mario Garritano
  • Patent number: 5732875
    Abstract: A method for producing a sector conductor for electric power cables is introduced, whereby a number of metal wires are joined closely together into a core (8) with a sector-shaped cross section. A lengthwise running metal strip is formed around the core (8) and its longitudinally abutting edges are welded into a tube (9), whose dimensions are reduced so that it lies closely against the core (8) and surrounds it.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: March 31, 1998
    Assignee: Alcatel Kabel AG & Co.
    Inventors: Gerhard Ziemek, Michael Meyer
  • Patent number: 5554826
    Abstract: An electrical overhead transmission conductor cable having a steel reinforcing core which exhibits improved characteristics and unexpected conductivity above about 64% IACS is manufactured of a steel core covered by at least one stranding layer which is formed of round or trapezoidal shaped wire strands subjected to annealing before heat treatment and drawn and stress-relieved/annealed after stranding is completed, to provide a finished cable which includes an aluminum conductive portion which is dead soft, or "O" temper. The steel core of the cable carries substantially the entire tension load of both the core and conductors when suspended between vertical towers. The overhead transmission cable may be formed of trapezoidal cross section conductors wires for improved vibration performance characteristics.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: September 10, 1996
    Assignee: Southwire Company
    Inventor: Bobby C. Gentry
  • Patent number: 5496969
    Abstract: Concentric Compressed Unilay Stranded Conductors are formed of certain combinations of compressed wires, such as 1+7+12, 1+6+11 or 1+7+12+17, which have nominally equal diameters. The combinations of conductors or wires are selected so that the number of wires in any two adjacent layers, including a central layer, are not divisible by a common number with the exception of the integer one. The stranded conductors are optionally formed to have sectored cross-sectional configurations.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: March 5, 1996
    Assignee: Ceeco Machinery Manufacturing Ltd.
    Inventor: Andrew Blackmore
  • Patent number: 5438161
    Abstract: An electrical path or interconnection arrangement is provided within a formed support body of polymeric material that exhibits volumetric changes during and after the forming thereof. The electrical path or interconnection arrangement provides an accurately positioned electrically conductive path through the material of the support body and also responds to, accommodates and alleviates the effects of forces at the interface between the material of the support body and the electrical path or interconnection arrangement that occur during and after the forming of the support body. The interconnection arrangement exhibits predetermined deformability/compressibility characteristics to alleviate stresses caused by the volumetric changes of the polymeric material. In a preferred arrangement, the interconnection arrangement includes an elongated tubular conductor fabricated from a metallic material.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: August 1, 1995
    Assignee: S&C Electric Company
    Inventors: Glenn R. Borchardt, Roy T. Swanson, James W. Barker, Jr.
  • Patent number: 5418333
    Abstract: A method of manufacture and a resultant cable structure of elliptical stranded cable which optimizes the use of existing conventional stranding machines. In accordance with the present invention, one or more layers of shaped, non-circular, wires are interposed to provide support between the inner core of substantially round wires each having essentially the same diameter and the outer layer of round wires of different diameters, which outer layer includes round wires of different diameters which are arranged to provide the minor and major axes of the elliptical cable. The shaped wires are preferably trapezoidal in shape. Alternatively, the shaped wires may be arcuately shaped elliptical wires subtending an angle determined by dividing by the number of shaped wires (for example, for a twelve wire layer) and having an aspect ratio (ratio of major axis X dimension to minor axis Y dimension) sufficient to provide support between the inner core and outer layer of round wires.
    Type: Grant
    Filed: July 8, 1993
    Date of Patent: May 23, 1995
    Assignee: Southwire Company
    Inventor: Eugene T. Sanders
  • Patent number: 5248851
    Abstract: A pseudo rod, fabricated from several plate sections joined together at their edges and having a cross-section resembling a polygon approximates a rod having a circular cross section. Using multiple plates joined at their edges permits growing a crystalline material on the planar faced substrates and if the plates are crystalline material, the crystalline material grown thereon can have improved current carrying capability.
    Type: Grant
    Filed: December 2, 1992
    Date of Patent: September 28, 1993
    Assignee: Motorola, Inc.
    Inventors: Marc K. Chason, Richard S. Kommrusch, Pankaj B. Desai
  • Patent number: 5171942
    Abstract: An oval or elliptical shaped overhead conductor that is twisted along its length to provide a continuously varying profile to the wind. A single core is comprised of a circular center wire wrapped by circular wires and the core is surrounded or encased by one or more layers of wire strands, including strands of different size from that of the core wires. Each layer is helically wound in a direction opposite to the underlying layers. The surrounding strands may be circular, with the strand sizes symmetrically arranged to result in a substantially oval or elliptical cross-section. Alternatively, the strands may be shaped into symmetrically arranged non-circular arcuate cross-sections, which when wound together result in an oval or elliptical conductor cross-section. The core strands are each circular or round wires having the same diameter, with the result that the core is easy and inexpensive to manufacture.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: December 15, 1992
    Assignee: Southwire Company
    Inventor: Wilber F. Powers
  • Patent number: 5149917
    Abstract: Strands of a copper alloy containing 0.2 to 10 percent by weight of Sn are braided to form a stranded wire for a wire conductor for a harness having a conductor sectional area of 0.03 to 0.3 mm.sup.2. After the braiding, preferably stranded wire is heat treated so that its tensile strength is maintained at a prescribed level. The wire conductor for a harness has a breaking strength which is equivalent to that of a conventional harness wire, and is hardly broken by an impact. The wire conductor maintains its straightness, and strand ends do not fray upon cutting.
    Type: Grant
    Filed: May 7, 1991
    Date of Patent: September 22, 1992
    Assignees: Sumitomo Electric Industries, Ltd., Sumitomo Wiring Systems, Ltd.
    Inventors: Kazuo Sawada, Atsuhiko Fujii, Yoshihiro Nakai, Naoyuki Ohkubo, Hajime Shiraishi, Fumio Ono, Katsushi Matsuda, Kazunori Tsuji
  • Patent number: 5036166
    Abstract: An electric fence line for use in confining livestock is formed of strands of a high strength and high visibility electrically insulative material, which have been woven, twisted, or braided, together with at least one highly electrically conductive low electrical resistance metal strand, such as copper wire, and at least one high-strength metal strand of higher electrical resistance, such as stainless steel. The metal strands are oriented in touching relation, either continuously or at positions spaced longitudinally of the metal strands, the high-strength metal strand providing an electrical bridge between ends of the highly electrically conductive strand or strands in the event of breakage of the highly electrically conductive strand, whereby to provide electrical continuity in the fence line with only a minimal increase in the total electrical resistance of the fence line.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: July 30, 1991
    Assignee: Gallagher Electronics Limited
    Inventor: Dion V. Monopoli
  • Patent number: 5030797
    Abstract: A flexible power current conductor (1) comprises a number of thin copper foils and is provided with through-going oblong holes (5) for clamping bolts at each end. The foils are held together in a middle area by means of a thermo-shrinking insulating plastic material which engages incisions (4) and secures the foils in relation to each other.
    Type: Grant
    Filed: September 17, 1990
    Date of Patent: July 9, 1991
    Inventor: Jorgen Logstrup
  • Patent number: 4973370
    Abstract: Braided fine wire cable is prepared for termination by electrical terminals by a coating of dielectric material such as curable varnish which coats and embeds the myriad of fine wires. The coating upon hardening imparts structural integrity to the otherwise very flexible cable, enabling handling. The coating also retains the wire portions many of which may be severed during application of electrical terminals thereto to obtain electrical connection of portions of the terminals with ends or surfaces of many of the wires, thus preventing disintegration of the cable's termination region when the terminals are applied. The hardened coating also enables the cable region to be shaped and formed to some extent, even including cutting or notching the cable, to adapt the cable region to the structure of the terminals, enabling use of existing terminals used for terminating solid flat conductor cable, for example.
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: November 27, 1990
    Assignee: AMP Incorporated
    Inventor: Earl R. Kreinberg
  • Patent number: 4912446
    Abstract: A cryogenically coolable inductive coil including: a multicomponent conductor comprising a plurality of components, each component including a cable of conductive material having a longitudinal axis about which the cable is twisted, the cable being wrapped helically and being compacted, after wrapping, to minimize voids in the cable and to give the component a polygonal profile, the components being disposed parallel, and adjacent, to one another with mutually facing sides of adjacent components being in contact with one another; and an electrical insulating and support structure at least partially surrounding the conductor for supporting stresses induced in the conductor due to magnetic fields created by the flow of current through the conductor, the conductor and the structure being wound to form the coil.
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: March 27, 1990
    Assignee: Westinghouse Electric Corp.
    Inventors: Sharad K. Singh, Donald T. Hackworth
  • Patent number: 4889963
    Abstract: A flexible electrically conductive sheet includes a wove fabric of fibers including stainless steel fibers, the woven fabric being impregnated with a synthetic resin material. Portions of the stainless steel fibers are exposed on surfaces of the synthetic resin material. By bringing an electrostatically charged object into contact with the exposed stainless steel fibers, the charged static electricity can be removed.
    Type: Grant
    Filed: November 14, 1988
    Date of Patent: December 26, 1989
    Assignee: Tokyo Sen-I Kogyo Co., Ltd.
    Inventor: Kozo Onai
  • Patent number: 4829417
    Abstract: The secondary winding of a high power transformer for clocked power supplies is composed of a plurality of skeins extending parallel to one another which are, in turn, constructed of a plurality of stranded conductors extending parallel to one another, whereby the stranded conductors are composed of wire-shaped individual conductors respectively provided with an insulating surface and twisted or woven with one another. All stranded conductors are electrically and mechanically connected to one another at both ends of their respective skeins and all skeins are connected to one another at one end of the secondary winding and connected to one another across respective rectifiers at the other end thereof.
    Type: Grant
    Filed: July 9, 1987
    Date of Patent: May 9, 1989
    Assignee: Siemens Aktiengesellschaft
    Inventors: Horst Morgott, Edmund Poetsch, Erich Schmidtner, Hans-Hasso Goercke
  • Patent number: 4778246
    Abstract: A high tensile strength transmission cable having a plurality of main compacted strands. The strands surround, and are adjacent to, an uncompacted and moveable core which may form or contain one or more transmission elements. A method for making such a high strength transmission cable includes the steps of compacting the cable formed by a plurality of pre-compacted strands wound around a hard core wire, opening the strands to replace the hard core wire with a soft core containing transmission elements, and then closing the strands.
    Type: Grant
    Filed: May 15, 1985
    Date of Patent: October 18, 1988
    Assignee: Acco Babcock Industries, Inc.
    Inventor: David W. Carroll
  • Patent number: 4664158
    Abstract: An elastic conductive fabric for use as a grounding strap and the method of making the same are disclosed. The fabric is woven utilizing elastic yarn ends intermingled with conductive yarn ends. The weaving process is carried out while the elastic yarn ends are distended by at least 150% and preferably 250-400% as compared with the relaxed condition thereof. Preferably the conductive yarn is woven in a two over one pattern so that when tension is released in the elastic ends, the crests of the conductive ends which span two picks will project a substantial distance from the fabric surface. The opposite face of the fabric may be comprised of insulative ends likewise woven in a two over one pattern to provide enlarged crests at said face. Locking yarn ends maintain the conductive crests in a perpendicular condition relative to the fabric body.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: May 12, 1987
    Assignee: C. M. Offray & Son, Inc.
    Inventor: Timothy A. Sands
  • Patent number: 4654477
    Abstract: The electric conductor comprises at least three kinds of element wires which are electrically connected with each other at least at their both ends, and the electric conductor performs a superior signal transmission characteristics for audio signal and so on.
    Type: Grant
    Filed: November 30, 1984
    Date of Patent: March 31, 1987
    Assignees: Osaka Fuji Kogyo Co., Ltd., Nippon Light Metal Co., Ltd.
    Inventor: Yukitomo Isoda
  • Patent number: 4634805
    Abstract: A conductive cable made up of a plurality of polyaramid elements referred to as tows, which are woven, twisted, or braided together, in which each of said tows comprises a large number of individual fine filaments (usually about 1,000 or so) with each of the individual filaments being coated with an adherent metal coating such as copper, nickel, silver, zinc, cadmium, platinum, iron, cobalt, chromium, tin, lead, rhodium, ruthenium, and indium in single or multiple layers so as to provide strength and good electrical conductivity. Woven polyaramid fabric is also disclosed with the individual filaments in each element or tow of the fabric having been treated in the same manner.Methods of making such a cable or woven fabric are also disclosed.
    Type: Grant
    Filed: May 2, 1985
    Date of Patent: January 6, 1987
    Assignee: Material Concepts, Inc.
    Inventor: Ralph F. Orban
  • Patent number: 4605819
    Abstract: A conductor for high voltage of electricity, comprising a plurality of circular conductor wires which are wound helically to form a circular cable and a protrusion wire which is helically wound with the conductor wires as part of the cable in the outer periphery of the cable, so as to protrude beyond the outer periphery of the cable.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: August 12, 1986
    Inventor: Frank W. Warburton
  • Patent number: 4552990
    Abstract: A conductor, provided with insulation for forming windings for transformers and other inductive apparatus comprises two substantially rectangular uninsulated conductor strands, which are arranged with a flat side of one conductor strand facing a flat side of the other conductor strand and with an insulating layer arranged between the flat conductor sides, of a material which forms a glued joint between the conductor strands and which contains a spacer of insulating material to ensure that the conductor strands are held at a distance from each other. The glued joint may be provided either before or after the forming of the conductor into a winding. After the glued joint has been achieved, a winding manufactured from the conductor has a high breaking strength and low additional losses. The conductor is suitable for the manufacture of complicated windings as well, such as interleaved disc windings.
    Type: Grant
    Filed: May 19, 1983
    Date of Patent: November 12, 1985
    Assignee: Asea Aktiebolag
    Inventors: Bo G. Persson, Erich Spicar
  • Patent number: 4529837
    Abstract: Improved multistrand Rutherford-type superconductor cable is produced by using strands which are preformed, prior to being wound into the cable, so that each strand has a variable cross section, with successive portions having a substantially round cross section, a transitional oval cross section, a rectangular cross section, a transitional oval cross section, a round cross section and so forth, in repetitive cycles along the length of the strand. The cable is wound and flattened so that the portions of rectangular cross section extend across the two flat sides of the cable at the strand angle. The portions of round cross section are bent at the edges of the flattened cable, so as to extend between the two flat sides. The rectangular portions of the strands slide easily over one another, so as to facilitate flexing and bending of the cable, while also minimizing the possibility of causing damage to the strands by such flexing or bending.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: July 16, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Albert R. Borden
  • Patent number: 4518661
    Abstract: Electrically conductive bodies and methods of using same are disclosed which generally incorporate the feature of wire crossing wire at multiple sites of mutual contact throughout the body with the wire interconnected at the sites by a chemical deposition of metal to yield a rigid, open metallic lattice.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: May 21, 1985
    Inventor: Ralph E. Rippere
  • Patent number: 4439256
    Abstract: A cable comprised of coated conductors, wound together and compacted, has an insulating strip interposed between the two layers in which the conductors are disposed, to ensure good insulation therebetween. Apparatus for producing the cable includes a stranding machine, with which a hollow mandrel is used for the purpose of introducing the insulating strip between the layers of conductors, and a method for producing the cable is also provided.
    Type: Grant
    Filed: February 18, 1981
    Date of Patent: March 27, 1984
    Assignee: New England Electric Wire Corporation
    Inventor: Robert F. Meserve
  • Patent number: 4436954
    Abstract: A steel-cored aluminum cable for electric power conduction comprises a steel core including a plurality of steel wires and an aluminum coating disposed therearound in direct contact therewith and formed from an aluminum sheet and a plurality of aluminum staples disposed around the aluminum coating in direct contact with the aluminum coating along the entire innermost circumferential surface of the aluminum staples.
    Type: Grant
    Filed: August 3, 1981
    Date of Patent: March 13, 1984
    Inventors: Gyula Kaderjak, Albert Veres, Istvan Barkoczy, Janos Lonscsak
  • Patent number: 4384168
    Abstract: A conductor and method of making the conductor are provided for use in winding electrical coils which are cooled by a fluid communicating with the conductor. The conductor is cold worked through twisting and reshaping steps to form a generally rectangular cross section conductor having a plurality of helical cooling grooves extending axially of the conductor. The conductor configuration makes it suitable for a wide variety of winding applications and permits the use of simple strip insulation between turns and perforated sheet insulation between layers of the winding.
    Type: Grant
    Filed: May 12, 1981
    Date of Patent: May 17, 1983
    Assignee: The United States of America as represented by the Department of Energy
    Inventor: Walter J. Kenney
  • Patent number: 4367372
    Abstract: A flat multi-strand superconducting conductor with a separator.The conductor is constituted by transposed strands which form two layers (12, 14) on either side of an insulating separator (2, 3, 4) which is formed around a core (3, 4) including a continuous metal detector line so as to allow the transitions of the superconducting strands to be detected by measuring the voltage at the terminals of the conductor and compensating the induced voltage detected at the terminals of this detector line.Application to cryoalternators.
    Type: Grant
    Filed: April 6, 1981
    Date of Patent: January 4, 1983
    Assignees: Alsthom-Atlantique, Electricite de France Service National
    Inventors: Michel Kiblaire, Henri Nithart, Alain Fevrier, Jacques Maldy
  • Patent number: 4354917
    Abstract: This disclosure is directed to an asymmetric woven wire mesh current distributor for an electrode containing more conductive elements (portions) in one direction than in the other direction when installed in use in an electrode so that the greater number of wires is perpendicular to the major current feeder bars and span the narrow part (conductive path) of a rectangular air cathode. In accordance with the preferred embodiment of this invention, the current distributor is a woven wire mesh wherein the numerical ratio between the number of said perpendicular wires to said parallel wires ranges from about 1.5 to about 3:1.
    Type: Grant
    Filed: October 31, 1980
    Date of Patent: October 19, 1982
    Assignee: Diamond Shamrock Corporation
    Inventor: Frank Solomon
  • Patent number: 4350580
    Abstract: A current distributor for an electrode for an electrolytic cell for the electrolysis of aqueous solutions of ionic compounds is provided which comprises an electrically conductive material having a front surface comprised of a plurality of electrode-engaging means projecting from it for attachment to a foraminous electrode. The rear surface of the current collector is suitable for attachment to an electrical conductor. The novel current distributors are particularly suitable for use with reticulate electrodes.
    Type: Grant
    Filed: May 5, 1980
    Date of Patent: September 21, 1982
    Assignee: Olin Corporation
    Inventor: Igor V. Kadija
  • Patent number: 4317955
    Abstract: A barbed wire construction. The construction includes an iron wire having a longitudinally extending groove therein. A copper wire, coated with insulation, is inserted into the groove and extends along the groove. The iron and copper wires are coated.
    Type: Grant
    Filed: October 23, 1979
    Date of Patent: March 2, 1982
    Inventor: Oh Y. Choi
  • Patent number: 4154429
    Abstract: The invention is an improved method for the electrical grounding of insulation coated chain link fabric that is usually used for fences or similar enclosures. The invention provides a continuous wire at the top or bottom, or both, edges of the erected fabric that electrically connects each of the insulation coated wires which make up the fabric. The continuous wire is then grounded at intervals along the length of the fence or enclosure and thus effectively electrically grounds the fabric. Numerous variations in the configuration of the wire are included in the embodiments for accomplishing the grounding.
    Type: Grant
    Filed: April 28, 1977
    Date of Patent: May 15, 1979
    Assignee: Anchor Post Products, Inc.
    Inventor: Robert R. Brannan
  • Patent number: 4154430
    Abstract: The invention is an improved method for electrical grounding of plastics coated chain link fabric that is usually used for fences or similar enclosures. The invention provides a method for grounding by employing an insulating coating containing conductive particles to form a continuous linkage or electrical path through and between all wires that compose the fabric. The said fabric, after said continuous linkage or electrical path is established, is then grounded at various intervals along the length of the fence or enclosure and thus effectively electrically grounds the fabric.
    Type: Grant
    Filed: July 15, 1977
    Date of Patent: May 15, 1979
    Assignee: Anchor Post Products, Inc.
    Inventor: Walter L. Pfarr, Jr.
  • Patent number: 4079510
    Abstract: Disclosed is an electrical conductor formed from a plurality of elongate filaments, at least a portion of which have a non-circular cross section, the filaments arranged such that the conductor has a substantially smooth exterior surface and high density of material of the filaments in a cross section through the conductor perpendicular to its axis. A preferred method for forming such an electrical conductor involves the continuous electroforming of a plurality of elongate conductive filaments. After such filaments are stripped from a cathode track upon which they are deposited, a number of them are bunched and/or twisted together to form an electrically conductive strand. Finally, that strand is compacted to reduce its cross sectional area to provide it with a smooth exterior surface.
    Type: Grant
    Filed: August 23, 1976
    Date of Patent: March 21, 1978
    Assignee: Kennecott Copper Corporation
    Inventors: Kenneth W. McGrath, David W. Marshall, William R. O'Day, Jr., Thomas C. Wilder
  • Patent number: 3961832
    Abstract: A lightweight electrical cable comprises a plurality of laminations of loops of continuous strips of silver foil, defining an opening at least at one end thereof for receiving a battery post or other electrical connector, and a spring clip engagable with the cable end received on an electrical connector to readily releasably secure the cable in place. The method of making an electrical cable as described above is also disclosed.
    Type: Grant
    Filed: March 12, 1975
    Date of Patent: June 8, 1976
    Inventor: Richard E. Diggs
  • Patent number: H369
    Abstract: A mechanically stable, wound, multifilar, ribbon-type conductor having a cross-sectional aspect ratio which may be greater than 12:1, comprising a plurality of conductive strands wound to form a flattened helix containing a plastic strip into which the strands have been pressed so as to form a bond between the strip and the strands. The bond mechanically stabilizes the conductor under tension, preventing it from collapsing into a tubular configuration. In preferred embodiments the plastic strip may be polytetrafluoroethylene, and the conductive strands may be formed from a superconductive material. Conductors in accordance with the present invention may be manufactured by winding a plurality of conductive strands around a hollow mandrel; the cross-section of a hollow mandrel; the cross-section of the mandrel continuously varying from substantially circular to a high aspect ratio elipse while maintaining a constant circumference.
    Type: Grant
    Filed: March 15, 1982
    Date of Patent: November 3, 1987
    Assignee: The United States of America as represented by the Department of Energy
    Inventor: James G. Cottingham