Patents by Inventor Derek H. Dennis

Derek H. Dennis 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).

  • Telephone intercommunication set
    Patent number: D325381
    Type: Grant
    Filed: September 19, 1990
    Date of Patent: April 14, 1992
    Assignee: Stentofon A.S.
    Inventors: Derek H. Dennis, Jakob Jensen
  • Intercommunication apparatus without a hand set
    Patent number: D332095
    Type: Grant
    Filed: September 19, 1990
    Date of Patent: December 29, 1992
    Assignee: Stentofon AS
    Inventors: Derek H. Dennis, Jakob Jensen