Patents by Inventor Charles A. L. Ruhl

Charles A. L. Ruhl 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).

  • Hydrostatic transmission control with hydraulic follow-up
    Patent number: 4139985
    Abstract: A hydraulic follow-up for use with a hydraulic system placed between a rotating input member and a rotating output member. The hydraulic system is a hydrostatic transmission for driving a tractor, and comprises a hydrostatic pump and a hydrostatic motor driven by the pump. When the hydrostatic pump is angularly shifted with respect to the input member, the shifting is controlled by the hydraulic follow-up, which also shifts the motor in relation to the output member.
    Type: Grant
    Filed: October 25, 1977
    Date of Patent: February 20, 1979
    Assignee: International Harvester Company
    Inventors: Charles A. L. Ruhl, Edward Meyer, Probir K. Chatterjea