Patents by Inventor John W. Erwin

John W. Erwin 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).

  • Tamperproof construction for hydrant actuating nut
    Patent number: 4936336
    Abstract: A tamperproof construction for preventing actuation of the actuating nut of a fire hydrant comprising a nut actuating body for receiving the hydrant nut in turning relationship, set screws locking the nut actuating body to the actuating nut, a shroud permanently secured on the nut actuating body by means of a snap ring so that it covers the set screws but is rotatable on the nut actuating body, a bore in the shroud for permitting selective access to the set screws, a key-operated plug in the bore, a cap permanently and rotatably mounted on an end of the nut actuating body which protrudes through an opening in the shroud, and a limited axial portion of the nut actuating body exposed between the cap and shroud for receiving a specialized wrench.
    Type: Grant
    Filed: October 30, 1989
    Date of Patent: June 26, 1990
    Assignee: McGard, Inc.
    Inventors: Durham S. McCauley, John K. Waite, John W. Erwin