Patents by Inventor Karl Engman

Karl Engman 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).

  • Transformer
    Patent number: 6456179
    Abstract: A container (2) with an oil immersed core (1) and windings has corrugated walls. Bushing insulators (9,10) have pressure-resistant and water-resistant cable shoes (11). A tank encompasses another container (4) filled with insulating oil (3) and has pressure-resistant cable bushing (13) and connectors for electrical connections of the transformer.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: September 24, 2002
    Assignee: Merger Recipient ABB Oy
    Inventors: Johan Backa, Karl Engman, Torvald Haldin, Esa Virtanen