Patents by Inventor John W. Tompkins

John W. Tompkins 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).

  • Armored cattle guard
    Patent number: 4434975
    Abstract: A pre-cast concrete cattle guard having longitudinally extending rails and transversely extending beams. The upper edges of selected rails are armored with a protective metal cap which is securely anchored in the rails.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: March 6, 1984
    Inventor: John W. Tompkins