Patents by Inventor Nils V. Holmgren

Nils V. Holmgren has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4845324
    Abstract: Apparatus for opening and closing a switch, which apparatus comprises a lever mounted on a frame for pivotal movement between a first position and a second position, a first spring biasing the lever from the second position to the first position, a cam and follower for effecting pivotal movement of the lever from the first position to the second position against the influence of the first spring, a step on the cam for permitting movement of the lever from the second position to the first position under the influence of the first spring after the lever has moved from the first position to the second position, a member adapted to be connected to the switch and movable between a switch opening position and a switch closing position, which member is movable to the switch closing position in response to movement of the lever from the second position to the first position, a second spring displaceable between extended and contracted conditions, which second spring is extended to the extended condition in response t
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: July 4, 1989
    Assignee: Cooper Power Systems, Inc.
    Inventors: Donald R. Martin, Nils V. Holmgren
  • Patent number: 4821143
    Abstract: A switchgear apparatus comprising a row of pressure vessels, a frame including first and second generally horizontal, elongated members rigidified by the row of pressure vessels, an outer housing including a generally horizontal top portion supported by the frame, generally vertical, spaced apart side portions connected to the top portion, and a door which is movable between a lowered, closed position in which the door prevents access to the interior of the housing and a raised, open position in which the door affords access to the interior of the housing, the door including a generally planar first portion connected to the top portion for pivotal movement relative thereto about a generally horizontal axis, the first portion being angularly spaced from the top portion when the door is in the raised position, a mechanism for assisting manual movement of the door from the lowered position to the raised position, and a mechanism for releasably retaining the door in the raised position.
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: April 11, 1989
    Assignee: Cooper Power Systems, Inc.
    Inventors: Nils V. Holmgren, Donald R. Martin, Hinhsomchay Phouybanhdyt
  • Patent number: 4780581
    Abstract: A switch apparatus comprising a fixed tubular contact having an inner end, a movable tubular contact having an inner end and being movable between a closed position wherein the inner ends of the contacts overlap and an open position wherein the inner ends of the contacts are spaced apart, a piston fixed to the movable contact for movement thereiwth, a cylinder slideably receiving the piston and cooperating with the piston to define a variable volume pressure chamber which decreases in volume as the movable contact moves from the closed position to the open position, and a housing fixed to the piston and having an inner surface which cooperates with the piston to define an arc chamber containing the inner end of the movable contact, the housing having therein an aperture through which the fixed contact extends when the movable contact is in the closed position, and the arc chamber communicating with the pressure chamber so that gas is forced from the pressure chamber into the arc chamber when the movable conta
    Type: Grant
    Filed: October 30, 1987
    Date of Patent: October 25, 1988
    Assignee: RTE Corporation
    Inventors: Nils V. Holmgren, Donald R. Martin
  • Patent number: 4553008
    Abstract: An load interrupter is disclosed having the characteristics of an ordinary puffer interrupter and a self-extinguishing gas flow interrupter. The load interrupter comprises a generally hollow cylinder which is adapted to be filled with an arc extinguishing fluid and which has an electrically insulated nozzle at one end. A piston is sealingly and slidingly disposed within the cylinder so as to be movable between a first and second position to change the internal volume of the cylinder that is in flow communication with the nozzled end. A stop limits the relative motion between the piston and the nozzled end of the cylinder. A spring biases the piston against the stop. One of the two contacts across which the arc is formed is carried by the piston. The other contact is operated by a prime mover to move into and out of the chamber formed by the piston, cylinder and nozzle. Thus, under low current conditions, the piston follows the movement of the other contact.
    Type: Grant
    Filed: June 14, 1984
    Date of Patent: November 12, 1985
    Assignee: Cooper Industries, Inc.
    Inventors: Edward F. Veverka, Nils V. Holmgren, Donald R. Martin
  • Patent number: 4489226
    Abstract: An interrupter is provided having: an outer enclosure or tank adapted to contain an arc-extinguishing fluid; a fixed tubular electrical current carrying member disposed at one end of the tank; a movable tubular current carrying member disposed in the tank in an end-to-end relationship with the fixed electrical current member; a prime mover for stroking the movable current carrying member between an open position and a closed position; an electrically conductive piston means, carried by the movable electrical current carrying member, for supplying pressurized fluid into the gap formed between two current carrying members when the interrupter is opened and for purging the vicinity of the gap when the interrupter is closed; a non-electrically conductive base means, carried by the outer enclosure, for housing the piston means and for guiding the movement or the stroking of the movable current carrying member; and an insulated plenum means, carried by the piston means and disposed around the contacting ends of the
    Type: Grant
    Filed: September 3, 1982
    Date of Patent: December 18, 1984
    Assignee: McGraw-Edison Company
    Inventors: Nils V. Holmgren, Donald R. Martin
  • Patent number: 4464583
    Abstract: An apparatus is provided for single-point, multi-point or cross-bonding electrical power cables. The apparatus includes an electrically insulated housing which defines an access well, two electrical conductors each having one end disposed within the well, a cover for closing-off the well, a linking device carried by the cover for removably and electrically connecting together those ends of the two electrical conductors which are disposed within the well, and a connecting device for electrically connecting the linking device to a terminal on the exterior of the housing. In the preferred embodiment a movable over-voltage protective device or surge arrester is electrically interposed between the linking device and the connecting device. When the cover is installed two electrical conductors are electrically connected together and to the surge arrester. Other embodiments are described and illustrated.
    Type: Grant
    Filed: March 4, 1983
    Date of Patent: August 7, 1984
    Assignee: McGraw-Edison Company
    Inventor: Nils V. Holmgren
  • Patent number: 4445018
    Abstract: A unique, energy efficient puffer interrupter having a puffer piston and an opposed floating piston or head is described in detail. In one embodiment, the puffer interrupter is formed from a pair of electrical contacts which are disposed within a chamber filled with an arc extinguishing fluid. A prime mover or switching means is used to open and close the switch by moving one of the contacts with respect to the other. A puffer piston is disposed at one end of a cylinder surrounding the fixed contact. A floating piston is disposed at the opposite end of the cylinder and biased towards the moving contact assembly and away from the puffer piston. The puffer piston and the floating piston and the cylinder define a pressurization chamber, which is in fluid communication with the gap defined by the switch contacts. A pressurizing valve means controls the flow of gas from between the two pistons and into the gap thereformed when the switch is opened.
    Type: Grant
    Filed: January 7, 1982
    Date of Patent: April 24, 1984
    Assignee: McGraw-Edison Company
    Inventor: Nils V. Holmgren