Patents by Inventor James S. Hickman

James S. Hickman 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: 4790513
    Abstract: A solenoid valve assembly has a slidable valve member which responds to a selectively energizable solenoid coil and a spring to control the opening and closing of pressure and exhaust ports through movement of the valve member. When the pressure port is fully opened, the valve member is seated against a solenoid stop and port member. The solenoid stop and port member includes a central flow passage which serves as the exhaust passage for the valve assembly. The flow passage is surrounded by a valve seat area which includes a frusto-conical surface having a recess or groove formed therein. The frusto-conical surface and the groove therein reduces the flow forces imposed on the valve member which generally operate to assist seating of the valve member. By reducing the flow forces, the unseating force necessary to open the exhaust port is reduced resulting in lower spring and magnetic forces.
    Type: Grant
    Filed: July 5, 1985
    Date of Patent: December 13, 1988
    Assignee: General Motors Corporation
    Inventors: Ronald G. Davis, David S. Dennis, James S. Hickman, William J. Linch