Patents by Inventor William J. Gresham

William J. Gresham 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).

  • Kelly saver drive
    Patent number: 5107941
    Abstract: A split, solid mass, drive bushing-drive plate for use when a kelly is used to sever a length of well casing. The invention fits into the master bushing and prevents wear on the corners between the flat sides of the kelly.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: April 28, 1992
    Inventor: William J. Gresham