Patents by Inventor Robert D. Gilbert

Robert D. Gilbert 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).

  • Patent number: 3958484
    Abstract: Improvement in sealing means for wind instruments wherein pads are mounted on the cups of keys which are actuated to open one or more tone holes on such instruments which holes are normally closed by the pads. The improvement resides in the pads being comprised of a first layer of a relatively soft, closed-cell, cross-linked polyethylene foam material which is adapted to enter the tone hole of such instruments and seal it off from the atmosphere thus preventing air leaks through such holes and a second layer, bonded to the first layer, of a greater rigidity than the first layer, of a closed-cell polyethylene foam material which is adapted to be secured to the key cup thus forming a pad having a long life and one which is unaffected by moisture.
    Type: Grant
    Filed: May 29, 1975
    Date of Patent: May 25, 1976
    Assignee: Roberts' Products, Inc.
    Inventors: Robert E. Nelson, Robert D. Gilbert