Patents by Inventor Thomas Schwaninger

Thomas Schwaninger 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).

  • Sleeve for increasing retention value of a screw
    Patent number: 5332153
    Abstract: The retention value of a screw previously inserted into a wooden railroad tie is increased by an axially extending sleeve ( 20 ) having an external thread ( 24 ) and an internal thread (25). The thread revolutions of the internal thread (25) are offset axially by half (h) the thread pitch (H) of the external thread (24). Due to this offset of the threads, the screw is positioned in the sleeve so that its threads are located between the external thread revolutions affording a new retention, while the external thread (24) seats within the thread previously formed in the wooden railroad tie by the screw.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: July 26, 1994
    Assignee: Hilti Aktiengesellschaft
    Inventors: Erich Leibhard, Franz Popp, Wolfgang Ludwig, Thomas Schwaninger