Patents Assigned to Guthrie Canadian Investments Limited
  • Patent number: 5225802
    Abstract: A low loss composite spider arrangement for use in inductive electrical epment and an air core reactor incorporating the same in which a non-conductive or a conductive material having very low relative permeability and relatively high resistivity is used to fulfill the mechanical and structural requirements of the spider, and a relatively small amount of electrical conducting material, bonded to and preferably electrically isolated therefrom, is used to fulfill the electrical requirements of the spider.
    Type: Grant
    Filed: January 3, 1983
    Date of Patent: July 6, 1993
    Assignee: Trench Electric, a division of Guthrie Canadian Investments Limited
    Inventors: Richard F. Dudley, Patrick E. Burke
  • Patent number: 5027099
    Abstract: An air core reactor of the type having a plurality of coaxial coil windings connected electrically in parallel by structurally rigid spiders at opposite ends of the reactor. There are two electrically conductive spiders at least one end of the reactor. Selected ones of the coil windings are connected to one of the two spiders and further selected ones of the coil windings are connected to the other of the spiders at the one end. In the preferred form the windings connecterd offset from one another around the coaxially disposed coils. In a further preferred embodiment, there are two electrically conductive spiders at each of opposite ends of the coaxial coils. In a still further preferred form, at least some of the coil windings are wound at least two conductors high with the same number of turns and wherein the ends of said two conductors are circumferentially offset from one another by preferably 180.degree..
    Type: Grant
    Filed: March 30, 1988
    Date of Patent: June 25, 1991
    Assignee: Guthrie Canadian Investments Limited
    Inventors: Patrick E. Burke, Richard F. Dudley, Ralph S. Daniel
  • Patent number: 4916428
    Abstract: An electrical resistor having first and second cylindrical resistance windings helically wound closely adjacent one another about a common axis and wound in opposite directions about such axis. The helical windings of the resistor are connected in parallel and the resistor is provided with terminals for placing it in series with a circuit to provide a resistance in such circuit. The resistors are used in a power distribution system that includes a first system connected to a second system by a tie line. The resistors referred to as braking resistors are located adjacent at least one of the power sources and are connected to the tie line through one or more circuit breakers.
    Type: Grant
    Filed: December 19, 1988
    Date of Patent: April 10, 1990
    Assignee: 501 Guthrie Canadian Investments Limited
    Inventor: Patrick E. Burke
  • Patent number: 4874916
    Abstract: Improved electric induction heating apparatus wherein the coil has two or more windings of special low loss conductor with such windings electrically connected in parallel. The two or more windings can be wound simultaneously one on top of the other and/or disposed radially one outside of the other. The coil windings embedded in a rigid set resinous material thus providing a rigid cylindrical unit. At least one of the coil windings has the low loss conductor around a tube the latter providing a fluid flow path for circulatig cooling fluid therethrough by at least one of current balancing transformers, transposition of the windings, and appropriately choosing the number of turns of each coil layer. A split ring bus can be used at the ends of the coils to connect the windings in parallel and laminated steel yokes can be disposed about the coil.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: October 17, 1989
    Assignee: Guthrie Canadian Investments Limited
    Inventor: Patrick E. Burke
  • Patent number: 4775849
    Abstract: A gas insulated current transformer wherein the metal tank having the inductive unit therein is mounted on the hollow insulating bushing and preloaded with spring pressure so that when the insulating gas within the bushing and the container reaches a predetermined and maximum safe limit the excess build up of gas pressure is allowed to escape between the otherwise sealed contact between the container and the bushing.
    Type: Grant
    Filed: December 24, 1987
    Date of Patent: October 4, 1988
    Assignee: Guthrie Canadian Investments Limited
    Inventor: Howard R. Lucas