Patents by Inventor Yasushi Nakaisumi

Yasushi Nakaisumi 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: 4099704
    Abstract: Disclosed is a vacuum valve apparatus comprising a valve head, a motor for driving the valve head, means for checking the position of the valve adapted to issue a first signal upon detecting that the valve head is moved to be within a predetermined valve-closed range, means for checking electric current adapted to issue a second signal when the driving current for the motor is increased to a predetermined value, switching means adapted to cut the driving current supply to the motor upon detecting said second signal, and means for issueing a third signal for confirming the complete closure of the valve when both of the first and the second signals are simultaneously obtained.
    Type: Grant
    Filed: December 20, 1976
    Date of Patent: July 11, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Masahide Okumura, Yoshio Sakitani, Yasushi Nakaisumi, Toshiaki Nakata