Patents by Inventor John F. Lagenbach

John F. Lagenbach 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 door lock
    Patent number: 4844521
    Abstract: This invention involves a security lock for a door hinged on a first door jamb for swinging between an open position and a closed position in which the door is positioned between the first door jamb and a second door jambs.
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: July 4, 1989
    Inventors: George Langenbach, John F. Lagenbach