Patents by Inventor Donald Hatch

Donald Hatch 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).

  • Valves for hydraulic brakes
    Patent number: 4271937
    Abstract: Hydraulically-operable rotary friction brake comprising a retarding device incorporating hydraulically actuated operating members have a hydraulic circuit including a valve whereby in periods of operation a major portion of the hydraulic flow is directed through the hydraulically actuated operating members and in periods of non-actuation only a minor proportion of the hydraulic flow is directed through the operating members.
    Type: Grant
    Filed: November 29, 1977
    Date of Patent: June 9, 1981
    Assignee: Ferodo Limited
    Inventors: Donald Hatch, Christopher R. Ellis, Richard H. Gibbon, Walter R. Stirling
  • Method of producing grey cast iron brake rotors with uniform friction and wear characteristics
    Patent number: 4121925
    Abstract: The friction characteristics and wear rate of grey cast iron are controlled within pre-determined limits by controlling the content in the cast iron of an element which is capable of forming in the cast iron hard high melting discrete particles.
    Type: Grant
    Filed: August 11, 1977
    Date of Patent: October 24, 1978
    Assignee: Ferodo Limited
    Inventors: Barbara Jean Chapman, Donald Hatch