Patents by Inventor Setsuo Oshima

Setsuo Oshima 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).

  • Office line connection circuit during service interruptions in key telephone apparatus
    Patent number: 4260857
    Abstract: A switching matrix in the key service unit of a key telephone system is formed by several groups of relays, each group being associated with a particular station set and each relay in each group also being associated with a particular central office line. All of the relays, except one in each group, disconnect the associated station set from the associated line when the relay is de-energized. One relay in each group functions in the opposite manner to connect the associated station set to the associated line upon failure of the local power supply.
    Type: Grant
    Filed: January 30, 1979
    Date of Patent: April 7, 1981
    Assignees: Nippon Tsushin Kogyo KK, TIE/Communications, Inc.
    Inventors: Tsuyoshi Shinoi, Setsuo Oshima