Patents by Inventor David J. Haugen

David J. Haugen 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 hybrid vehicle with safe and efficient hydrostatic operation
    Patent number: 9032723
    Abstract: A shut off valve is configured to shut off flow from the high pressure fluid line to the high pressure accumulator in a series hydraulic hybrid vehicle in order to quickly raise system pressure in the high pressure fluid line and enable additional torque output from the hydraulic motor for vehicle propulsion. A pressure relief valve is further provided to vent excess flow from the high pressure line to the high pressure accumulator as needed to avoid exceeding a maximum desired system pressure in the high pressure fluid line, thereby providing for safe and efficient hydrostatic operation in the vehicle.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: May 19, 2015
    Assignee: The United States of America, as represented by the Administrator of the U.S. Environmental Protection Agency
    Inventor: David J Haugen
  • Hydraulic Hybrid Vehicle with Safe and Efficient Hydrostatic Operation
    Publication number: 20120324879
    Abstract: A shut off valve is configured to shut off flow from the high pressure fluid line to the high pressure accumulator in a series hydraulic hybrid vehicle in order to quickly raise system pressure in the high pressure fluid line and enable additional torque output from the hydraulic motor for vehicle propulsion. A pressure relief valve is further provided to vent excess flow from the high pressure line to the high pressure accumulator as needed to avoid exceeding a maximum desired system pressure in the high pressure fluid line, thereby providing for safe and efficient hydrostatic operation in the vehicle.
    Type: Application
    Filed: March 9, 2011
    Publication date: December 27, 2012
    Inventor: David J. Haugen