Patents by Inventor Howard L. Hull

Howard L. Hull 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).

  • Door lock device
    Patent number: 4004833
    Abstract: A lock bolt device which comprises a lock bolt received upon the shaft of a door knob and extending into an aperture in a retaining plate attached to the door jamb.
    Type: Grant
    Filed: October 17, 1975
    Date of Patent: January 25, 1977
    Inventor: Howard L. Hull