Patents by Inventor Robert Ernest Yapp

Robert Ernest Yapp 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: 4069889
    Abstract: A power steering system has a valve between the pump and steering unit. The valve maintains a constant pressure differential so that the pump is unable to deliver aerated fluid to the unit in the event of loss of fluid or fracture of a pipe.
    Type: Grant
    Filed: November 26, 1976
    Date of Patent: January 24, 1978
    Assignee: Massey-Ferguson Services N.V.
    Inventors: Robert Ernest Yapp, Derek John Smith