Patents by Inventor William F. Erdman

William F. Erdman 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: 11052881
    Abstract: A work machine includes an electric drive system. The work machine includes a prime mover, a machine controller, and a hydraulic control system. The hydraulic control system includes a pump, a control valve and a retarding control valve. The pump is configured to supply pressurized fluid to the hydraulic control system via a supply line. The control valve is fluidly coupled to the pump via the supply line, and includes a pressure relief valve. The retarding control valve is fluidly connected to the pump and the control valve. The retarding control valve includes a solenoid valve, an orifice and a check valve. The solenoid valve is coupled to the machine controller, the orifice restricts a flow of the pressurized fluid through the supply line, and the check valve is coupled to a discharge line, which branches from a point along the supply line between the solenoid valve and the orifice.
    Type: Grant
    Filed: July 23, 2020
    Date of Patent: July 6, 2021
    Assignee: Caterpillar Underground Mining Pty. Ltd.
    Inventors: Dayao Chen, William F. Erdman, Edward W. Mate