Patents by Inventor Edwin W. Turnquist

Edwin W. Turnquist 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: 4404891
    Abstract: An improved brake valve for a hydraulically powered winch which has one flow path permitting the relatively unrestricted flow of hydraulic fluid through the valve when the winch is being used to raise a load and a second flow path in which the flow of fluid is controlled in response to the pressure of fluid at the motor inlet when the winch is being used to lower a load. Of particular significance are a fixed area orifice, an annular restrictive passageway and a variable area orifice which cooperate to distribute the pressure drop in the control circuit so as to reduce the sensitivity of the valve to pressure fluctuations in the hydraulic motor circuit. Also of significance are seals used on the spool and damper piston to retard the movement of the spool and to produce a desirable hysteresis effect in its response to pilot pressure.
    Type: Grant
    Filed: August 18, 1980
    Date of Patent: September 20, 1983
    Assignee: Paccar Inc.
    Inventors: Edwin W. Turnquist, Rick J. Bentley