Patents by Inventor Darrell W. Brewer

Darrell W. Brewer 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: 5071327
    Abstract: This gerotor-type hydraulic motor operates at two speeds (low speed, high torque and high speed, low torque) at a given flow rate and pressure of driving hydraulic fluid. It includes first and second rotating power elements disposed along an axis. Between the first and second power elements are first and second commutators. Located between the two commutators is a valve piece which is an integral portion of the motor. The valve piece selectively directs fluid, either in parallel or in series, through the first and second commutators, respectively, to the first and second power elements. Preferably the valve piece includes a spool valve. Also preferably the valve piece includes inner and outer concentric galleries located on opposite sides of the spool valve.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: December 10, 1991
    Assignee: Parker Hannifin Corporation
    Inventor: Darrell W. Brewer