Patents by Inventor Marilyn S. Murphy

Marilyn S. Murphy 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: 4700794
    Abstract: An improved mechanical-over-hydraulic steering apparatus capable of providing automotive-type steering includes a steering wheel driven input control member, right and left turn control valves, and first and second actuators mounted for rotation along an axis common with the input control member. Each of the actuators has a cam operatively associated with a cam-following roller assembly that operates the respective control valve. The vehicle has a cross drive mechanism, and the steering apparatus includes an over-center variable displacement steering pump and associated displacement control controllably operated by first and second pilot lines connected to the right and left turn control valves. The steering pump controllably and bidirectionally communicates fluid to a steering motor for the steering input to the cross drive mechanism.
    Type: Grant
    Filed: July 14, 1986
    Date of Patent: October 20, 1987
    Assignee: Caterpillar Inc.
    Inventors: James R. Bernhagen, Elmer R. Crabb, Marilyn S. Murphy, Daniel G. Roley, Gene R. St. Germain, James H. Tunnell