Patents by Inventor Erwin A. Billman

Erwin A. Billman 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: 4317979
    Abstract: In an induction heating apparatus, direct sensing of the high frequency high power current flowing in the tank circuit to load the induction coils, is obtained with a coil current measuring transformer comprising one of the power current busses leading to the induction coil and a secondary winding of many ampere-turns wound around said one bus. The bus is given a half-loop shape to accommodate the secondary winding. The secondary winding is made of a magnetic core wound with many turns of Litz wire. Cooling tubes are cemented outside the wound secondary with conductive cement to form a heat sink with a circulation of cooling medium through the tube. The cement is divided in two parts separated by gaps to prevent circulation of induced currents. A cooling tube is installed between the core and wound wire to provide an internal heat sink.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: March 2, 1982
    Assignee: Westinghouse Electric Corp.
    Inventors: William E. Frank, Erwin A. Billman