Patents by Inventor Donald V. Knierim

Donald V. Knierim 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).

  • Security device
    Patent number: 4348879
    Abstract: The security device of the present invention is mounted in the floor of a building adjacent the hinge side of a door to be made secure. The security device has elements which can be elevated from their storage position to engage against the inner face of the door to prevent the door from being opened beyond a minimum amount. A lock is provided for holding the elements in their elevated position.
    Type: Grant
    Filed: November 7, 1980
    Date of Patent: September 14, 1982
    Inventor: Donald V. Knierim