Patents by Inventor Marc Doolittle

Marc Doolittle 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: 5713429
    Abstract: A power steering system includes first and second valve members (40 and 42) which are movable relative to each other to port fluid to a vehicle power steering motor (31) and a pump (24) for providing fluid to the first and second valve members (40 and 42) and the power steering motor. A force transmitting member (116) is connected with the first valve member (40) and movable toward and away from the second valve member (42) for applying a force to resist relative movement between the first and second valve members. A fluid pressure chamber (138) receives fluid from the pump (24), the pressure of which acts on the force transmitting member (116). The first and second valve members (40 and 42) include passages for conducting fluid to the fluid pressure chamber (138). A fixed size bleed orifice (182) conducts fluid from the pressure chamber (138) to a reservoir (32). The orifice (182) restricts the flow of fluid from the chamber (138) to the reservoir (32).
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: February 3, 1998
    Assignee: TRW Inc.
    Inventor: Marc Doolittle