Patents by Inventor Tadaharu Nakayama

Tadaharu Nakayama 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).

  • Cable fault locating apparatus having an earth current canceller
    Patent number: 4161688
    Abstract: The cable fault locating apparatus employing an inverted Murray bridge circuit having a ratio arm connected to open ends of a faulty cable and a sound return cable, a voltage source connected through a switch to both ends of the ratio arm and a galvanometer connected between the output terminal of the ratio arm and the ground is characterized by an earth current canceller connected either in series or parallel with the galvanometer so as to cancel a stray earth current.
    Type: Grant
    Filed: November 14, 1977
    Date of Patent: July 17, 1979
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Tadaharu Nakayama