Patents by Inventor Leonard A. Johnson

Leonard A. Johnson 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: 7199571
    Abstract: A probe apparatus disclosed for use in a separable connector includes an insulating body and spaced apart first and second electrical conductors in contact with the insulating body. The first and second electrical conductors have adjacent surfaces configured such that when an electrical potential is applied between the conductors, an electric field is formed between the conductors. The insulating body has an opening positioned between the conductors and adapted to receive a sensor such that a portion of the sensor is subjected to the electric field. A separable electrical connector system is described including the probe apparatus, as is a voltage sensing system including the probe apparatus and a voltage sensor positioned within the opening of the insulating body.
    Type: Grant
    Filed: July 27, 2004
    Date of Patent: April 3, 2007
    Assignee: Optisense Network, Inc.
    Inventors: Leonard A. Johnson, Joseph Yossi Harlev, John M. Branning, Jr., Robert D. Elliott
  • Patent number: 6215940
    Abstract: A high voltage insulator for use with optical fibers includes an insulative support rod with at least one optical fiber wrapped about the support rod. The optical fiber and support rod are covered by an outer elastomeric skirted insulative sleeve which squeezes the optical fibers against the support rod. A dielectric sealant, such as a silicone gel, is dispersed along the optical fiber to fill any voids which occur adjacent the optical fiber, thereby providing a void-free bond between the interior surfaces of the insulator. The elastomeric outer sleeve provides a resilient barrier against the ingress of moisture. In a preferred embodiment, an inner layer of elastomeric material is provided between the support rod and the optical fiber to provide additional cushioning of the fiber and to reduce the size of voids which may occur adjacent the fiber.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: April 10, 2001
    Assignee: 3M Innovative Properties Company
    Inventor: Leonard A. Johnson
  • Patent number: 5729005
    Abstract: A fiber optic subassembly for a Faraday-effect current sensor has an optical sensing fiber supported by a tubular holder in a square or rectangular configuration, with the three of the four corners thereof designed with bends which have a net zero bend-induced birefringence. The bends are formed by providing two loops which have effective angles of about 90.degree., the two loops lying in orthogonal planes, such that the fast axis of birefringence in the first loop is parallel to the slow axis of birefringence in the second loop, and the slow axis of birefringence in the first loop is parallel to the fast axis of birefringence in the second loop. In this manner, retardance accumulated in the first loop is offset by retardance accumulated in the second loop. If the loops are substantially identical, the offsetting of the retardance is effectively complete such that the bend exhibits negligible bend-induced birefringence.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: March 17, 1998
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Trevor W. MacDougall, Jay W. Dawson, Leonard A. Johnson
  • Patent number: 4226085
    Abstract: A single point attachment for a unitary tail pipe plug and convoluted lobe mixer supports the assembly in the tail pipe of a turbofan engine.
    Type: Grant
    Filed: February 13, 1978
    Date of Patent: October 7, 1980
    Assignee: United Technologies Corporation
    Inventor: Leonard A. Johnson
  • Patent number: 4053702
    Abstract: A means for relieving dielectric stress at a termination of a shielded and insulated high voltage cable. A smooth geometry high permittivity homogeneous material tube coaxially contacts both the ground electrode and the high voltage electrode. The tube consists of an elastomeric material having a permittivity in a range of from 10 to 25. The elastomeric material is non-rigid, thereby enabling the tube to be more readily fitted firmly around the cable and into the housing of the stress relief means. The ground electrode is the outer portion of the housing and diverges from the opening of the housing at the vicinity thereof in a direction toward the high voltage electrode. This dielectric stress relief means provides a satisfactory electric field gradient in applications wherein the rating is in a range from 15 kilovolts to 35 kilovolts.
    Type: Grant
    Filed: July 14, 1975
    Date of Patent: October 11, 1977
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Roy D. Erickson, Leonard A. Johnson, Edward I. Porwit