Patents by Inventor Robert Michael Sisk

Robert Michael Sisk 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: 4057701
    Abstract: A control system for a pair of hydraulic lift actuators for adjusting the position of a blade-carrying frame of a motor grader includes a pair of control levers respectively operatively connected to a pair of direction control valves which are, in turn, respectively connected to the pair of actuators and selectively operable by means of the levers to place the actuators in neutral, extension, retraction, and float conditions. Each of the levers includes a hollow handle section having an electric switch mounted therein and a finger-operable sleeve is reciprocably mounted on the handle section for selectively closing the switch. Each switch is connected to an electrically responsive portion of a respective one of the control valves and when closed causes the valve to shift to effect the float condition in an associated one of the actuators.
    Type: Grant
    Filed: August 9, 1976
    Date of Patent: November 8, 1977
    Assignee: Deere & Company
    Inventors: Robert Michael Sisk, Lary Lynn Williams