Patents by Inventor Eddie W. Christoffel

Eddie W. Christoffel 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).

  • Silencer for electric motion picture screens
    Patent number: 4159162
    Abstract: This invention relates to electric projection screens to effect the coordinated shifting of the screen surface into and out of picture-projecting position of the type mounted in or to the ceiling or to the wall of a room and more particularly to a means to quiet the operation of the screen roller tube and its appendages during rotation of the roller tube.
    Type: Grant
    Filed: May 22, 1978
    Date of Patent: June 26, 1979
    Assignee: Da-Lite Screen Co. Inc.
    Inventor: Eddie W. Christoffel