Multiple Conductor Patents (Class 174/26R)
  • Patent number: 4994632
    Abstract: A paper-polymeric material, laminated tape, an electric cable insulated with such tape and a method of making the tape. The tape includes a film of polymeric material to at least one surface of which a paper tape comprising cellulose fibers is bonded by contacting the paper tape at room temperature with the film heated to a temperature above its melting temperature. Prior to contacting the paper tape with the heated film, fibrils are caused to project from at least one surface of the paper tape by subjecting it to a high voltage, electrostatic field. In the laminated tape, the fibrils are embedded in the material of the film to provide an improved bond between the film and the paper tape.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: February 19, 1991
    Assignee: Societa' Cavi Pirelli S.p.A.
    Inventors: Claudio Bosisio, Antonio Campana
  • Patent number: 4639544
    Abstract: In an alternating current pipe-type cable system in which a group of individual insulated conductors are loosely disposed eccentrically within a conduit, an electromagnetic field shaping device interposed between the conductors and the conduit wall, so as to line the wall is configured so as to reduce eddy current losses in the conduit and in the conductors. The device is in the form of a slotted cylinder positioned so that the slot is diametrically opposite the group of conductors thereby to redistribute the magnetic flux induced. The device is preferably laminated in the radial and axial directions.
    Type: Grant
    Filed: August 1, 1985
    Date of Patent: January 27, 1987
    Inventors: Joseph H. Dableh, Raymond D. Findlay
  • Patent number: 4613923
    Abstract: 1-phenyl-1-tetrahydronaphthyl-ethane or an alkyl-substituted derivative thereof is useful as dielectric fluid in capacitors and undersea power cables having low flammability, high aromaticity and high density.
    Type: Grant
    Filed: October 17, 1984
    Date of Patent: September 23, 1986
    Assignee: Exxon Research & Engineering Co.
    Inventors: Wolfgang Gunter, Guido Nespoli
  • Patent number: 4602121
    Abstract: An oil-filled electric cable in which the solid insulation is formed, at least in part, by separately applied, alternate layers of cellulose paper tape and of film tapes made of a plastic. Prior to application of the tapes around the cable conductor, the moisture content of the paper tape is selected and the swelling of the plastic tape by the oil after application is adjusted, if necessary, such as by immersing the plastic tape in the oil prior to application, so that the swelling of the plastic tape by the oil in the formed cable is offset by the shrinkage of the paper tape during drying of the cable. Also, apparatus for pre-swelling the plastic tape.
    Type: Grant
    Filed: January 11, 1985
    Date of Patent: July 22, 1986
    Assignee: Societa' Cavi Pirelli S.p.A.
    Inventor: Paolo G. Priaroggia
  • Patent number: 4536610
    Abstract: An oil-filled, multi-core, electric cable having three cores within a metal sheath. Each core has a conductor surrounded by insulation and has substantially the same outer dimensions as the other cores. One conductor is made of copper and has a central oil duct. The other conductors are made of stranded aluminum wires in side-by-side and contacting relation and the ratio of the cross-sectional area of the metal of the copper conductor to the cross-sectional area of the metal of each aluminum conductor is the reciprocal of the ratio of the electrical conductivities thereof.
    Type: Grant
    Filed: June 18, 1984
    Date of Patent: August 20, 1985
    Assignee: Societa' Cavi Pirelli, S.p.A.
    Inventor: Alberto Giussani
  • Patent number: 4523648
    Abstract: An electric cable having a fluid-tight, metal sheath containing a plurality of cores without oil ducts, each including a conductor surrounded by insulation, and a separate tubular member adjacent and contacting two of the cores and having an oil duct of a cross-sectional area at least equal to the cross-sectional area of the sum of the oil duct cross-sectional areas normally included in each core. The spaces between the tubular member and the cores and between the cores, the tubular member and the sheath are filled with an insulating filler, and the insulation of the cores and the filler are impregnated with an insulating oil and the duct of the tubular member is filled with the insulating oil. The sheath contacts the outer surfaces of the tubular member and the cores, and the oil duct of the tubular member contains a plurality of longitudinally spaced, oil flow restrictors.
    Type: Grant
    Filed: February 9, 1984
    Date of Patent: June 18, 1985
    Assignee: Societa Cavi Pirelli S.p.A.
    Inventors: Francesco Strada, Giuseppe Bazzi
  • Patent number: 4491684
    Abstract: A flameproof electrical insulating fluid and an electrical cable impregnated with such fluid, the insulating fluid being a mixture of a polymethylsiloxane having a viscosity greater than 5 centistokes at 25.degree. C. and an aromatic compound corresponding to the chemical formula: ##STR1## where R is an aliphatic radical and said aromatic compound is present in the mixture in an amount from 0.5% to 10% by weight of the total weight of the mixture. Preferably, the aromatic compound is isopropyldiphenyl.
    Type: Grant
    Filed: April 29, 1983
    Date of Patent: January 1, 1985
    Assignee: Societa Cavi Pirelli S.p.A.
    Inventor: Bernardino Vecellio
  • Patent number: 4487991
    Abstract: A high voltage oil-impregnated electrical cable with fully polymer taped insulation operable to 765 kV. Biaxially oriented, specially processed, polyethylene, polybutene or polypropylene tape with an embossed pattern is wound in multiple layers over a conductive core with a permeable screen around the insulation. Conventional oil which closely matches the dielectric constant of the tape is used, and the cable can be impregnated after field installation because of its excellent impregnation characteristics.
    Type: Grant
    Filed: July 15, 1983
    Date of Patent: December 11, 1984
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Eric B. Forsyth, Albert C. Muller
  • Patent number: 4407854
    Abstract: Heat treating stranded together conductors in a reeled condition by passing electrical current along a path through some of the conductors in one direction around the reel and then through other conductors in the opposite direction around the reel. In preferred methods, the current is passed in one direction through one half of the conductors and then in the opposite direction through the other half.
    Type: Grant
    Filed: March 24, 1981
    Date of Patent: October 4, 1983
    Assignee: Northern Telecom Limited
    Inventor: Ali Pan
  • Patent number: 4366770
    Abstract: In order to reach every void between the individual cable conductors, particularly when filling a multi-pair communication cable, the water repellent substance is supplied to the cable core in great excess; a filling basin surrounding the filling station proper collects the re-emerging excess substance.
    Type: Grant
    Filed: May 1, 1978
    Date of Patent: January 4, 1983
    Assignee: Siemens Aktiengesellschaft
    Inventors: Horst Eckstein, Willi Seyfart, Norbert Sutor
  • Patent number: 4207427
    Abstract: An electric power cable having a Milliken-type conductor comprising at least four sectors, the conductor being paper-insulated and oil filled and each sector comprising metal wires stranded together. Each wire is covered with a layer of a cross-linked synthetic resin having a thermal classification of 120.degree. C., a CEI resistance to abrasion of at least 50 cycles, a CEI thermal pressure value higher than 170.degree. C. and an insulating oil contaminating effect of substantially zero, such resin also being substantially completely volatizable by the heat used for joining cables by welding. Preferred resins are a polyvinyl-acetal resin, such as a polyvinyl-formal resin, cross-linked with a phenol resin and, optionally, a melamine resin and such with the addition of a blocked isocyanate.
    Type: Grant
    Filed: March 15, 1978
    Date of Patent: June 10, 1980
    Assignee: Industrie Pirelli S.p.A.
    Inventors: Germano Beretta, Cesare Seveso, Giulio Tuci
  • Patent number: 4118593
    Abstract: A process for making a multi-core, fluid impregnated, electric, submarine cable of long length in which each core is separately formed, impregnated and sheathed before the so-formed units are combined within an armor layer which is covered by a bituminous material. Each unit is formed by forming a conductor of long length having an oil conduit therein. The conductor is covered by paper tape insulation layers, conductive screening layers optionally being applied before and after the covering of the conductor by the paper tape. The so-formed core is then vacuum treated and impregnated with insulating oil, covered with a fluid impermeable sheath which is then protected by blindage of metal tape. Over the blindage, a plastics sheath is formed, and the so-formed unit is combined with similar units which are covered by the armor layer of metal and the layer of bituminous material. The spaces between units and between the units and the armor layer may be filled with a filler material.
    Type: Grant
    Filed: November 24, 1976
    Date of Patent: October 3, 1978
    Assignee: Industrie Pirelli Societa per Azioni
    Inventor: Andrea Borroni