Patents by Inventor Edwin W. Thomas

Edwin W. Thomas 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).

  • Differential pressure energized circulating valve
    Patent number: 4481973
    Abstract: A circulating valve is provided for connection into the tubing string of a well for establishing selective flow of fluid between the tubing string and the well casing. The circulating valve incorporates a valve body which is adapted for connection into the tubing string of the well, which body defines a flow passage in registry with the flow passage of the tubing string. A valve seat is provided on the valve body and an outlet opening is defined downstream of the valve seat which is of sufficiently restricted dimension to permit opening of the valve at a particular injection pressure and to permit maintenance of the valve open condition by means of a pressure lower than the valve opening injection pressure.
    Type: Grant
    Filed: January 31, 1983
    Date of Patent: November 13, 1984
    Assignee: O'Brien Goins Engineering, Inc.
    Inventors: Thomas B. O'Brien, Edwin W. Thomas