Patents by Inventor Tadao Uchida

Tadao Uchida 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: 4669504
    Abstract: A hydraulic control solenoid valve comprising a plunger provided in a coil case and a shaft freely shiftable in a body. The shaft is provided with a first spool valve and a second spool valve. A feedback chamber is provided in the body and on the side of the first spool valve. A round shaped thin plate is fixed to the end of the first spool valve and positioned in the feedback chamber so as to form a constricted part of a flow passage formed between an interior wall of the feedback chamber and a peripheral surface of the thin plate. The cross-sectional area (S.sub.2) of the constricted part is not greater than 0.04 of the side surface area (S.sub.1) of the thin plate. The thin plate adds the damping coefficient (C.sub.d) and also functions as the stabilization of the behavior of the spool valves. The thin plate facilitates the prevention of the resonance phenomenon of the spool valves.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: June 2, 1987
    Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.
    Inventors: Yutaka Fujitsugu, Tomoo Ito, Tadao Uchida