Patents by Inventor Allen R. Markham

Allen R. Markham 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).

  • Plumbing test plug and method
    Patent number: 7021337
    Abstract: An improved screw in test plug covering the opening of a test plug opening adapted to removably secure inflatable test balls thereto for inflation therein for water column pressure testing, and deflation for release of the water before removal of the test plug and test ball from the plumbing system.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: April 4, 2006
    Inventor: Allen R. Markham