Patents by Inventor Eizo Urata

Eizo Urata 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).

  • 29
    Patent number: 5186213
    Abstract: An improved hydraulic servo-valve including a spool (10, 10R, 10L) adapted to slidably move in a valve body (1) to change the direction of flow of a working liquid and vary a flow rate of the working liquid, nozzle back-pressure chambers (18, 18R, 18L) to which a pilot pressure is applied for displacing the spool (10, 10R, 10L), and a flapper mechanism comprising nozzles (19, 19R, 19L) and flappers (20, 20R, 20L) is disclosed. Static pressure bearings (14R, 14L, 141R, 141L, 142R, 142L) are formed at opposite ends of the spool (10, 10R, 10L). In addition, the hydraulic servo-valve is formed with passages extend from a pump port (P) to the nozzle back-pressure chambers (18, 18R, 18L) via the static pressure bearings (14R, 14L, 141R, 141L, 142R, 142L).
    Type: Grant
    Filed: June 10, 1991
    Date of Patent: February 16, 1993
    Assignees: Ebara Research Co. Ltd., Eizo Urata
    Inventors: Eizo Urata, Shinpei Miyakawa