Patents by Inventor Gramling William D.

Gramling William D. 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).

  • Pressure-operated valving for oil and gas well swabs
    Patent number: 4712981
    Abstract: Apparatus and method of utilizing differential pressure to seat an almost-closed valve ball. Included are apparatus and means to protect valve ball from excessive closing force. Also included is a multiple valve arrangement to relieve excessive differential pressure.
    Type: Grant
    Filed: October 29, 1986
    Date of Patent: December 15, 1987
    Inventor: Gramling William D.