Patents by Inventor Soutarou Tanaka

Soutarou Tanaka 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).

  • Hydraulic pilot operation circuit and valve for quickly discharging oil
    Patent number: 5081905
    Abstract: A hydraulic control valve is controlled and changed over by a hydraulic pressure output from a remote control valve. A change-over valve is provided between an output port of the remote control valve and a pilot port of the hydraulic control valve. The change-over valve connects the output port of the remote control valve to the pilot port of the hydraulic control valve when the remote control valve is operated, and it connects the pilot port of the hydraulic control valve to a tank when the remote control valve is set to the neutral position. The change-over valve comprises a hydraulic change-over valve capable of establishing the above states of connection by the hydraulic pressure output from the remote control valve, or an electromagnetic change-over valve capable of establishing the above states of connection by electrically detecting the operation of the remote control valve.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: January 21, 1992
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takashi Yagyu, Soutarou Tanaka, Kimio Katsuki