Patents by Inventor Douglas R. Hart

Douglas R. Hart 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).

  • Valve locking device and method
    Patent number: 5927313
    Abstract: A valve locking device has a rigid covering member with an axial bore extending inside it. The bottom of the covering member has an annular skirt, and an annular groove is formed in the interior wall of the skirt. A resilient retaining ring with opposite terminal ends resides in the groove. The groove has a diameter greater than the outer diameter of the retaining ring so that the ring can be expanded radially within the groove to the extent that the interior diameter of the retaining ring is larger than the diameter of the axial bore. The skirt portion of the covering member has a cut out for accessing the terminal ends of the retaining ring with retaining ring pliers. The terminal ends of the ring have bores for receiving tines on the pliers.
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: July 27, 1999
    Inventor: Douglas R. Hart