Patents by Inventor Christopher J. Kolbe

Christopher J. Kolbe 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).

  • Hydraulic Actuator Control Circuit With Pressure Operated Counterbalancing Valves
    Publication number: 20080034957
    Abstract: A valve assembly controls fluid flow between first and second ports of a hydraulic actuator and each of a supply line and a return line. A first electrohydraulic proportional valve is connected between the supply line and the first port, and second electrohydraulic proportional valve is connected between the supply line and the second port. A first counterbalance valve couples the second port to the return line and operates in response to pressure created by the first electrohydraulic proportional valve and the first port. A second counterbalance valve couples the first port to the return line and operates in response to pressure created by the second electrohydraulic proportional valve and the second port. Thus operation of the first counterbalance valve is slaved to the first electrohydraulic proportional valve, and the second counterbalance valve is slaved to the second electrohydraulic proportional valve.
    Type: Application
    Filed: August 9, 2006
    Publication date: February 14, 2008
    Inventors: Dwight B. Stephenson, Joseph L. Pfaff, Christopher J. Kolbe, Robert J. Valenta, Eric P. Hamkins