Patents by Inventor Aaron D. Friend

Aaron D. Friend 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).

  • Propulsion control system for electrically powered vehicles
    Patent number: 3974429
    Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.
    Type: Grant
    Filed: May 1, 1974
    Date of Patent: August 10, 1976
    Assignee: R. G. LeTourneau, Inc.
    Inventors: Aaron D. Friend, Hilmer C. Lindahl
  • Propulsion control system for electrically powered vehicles
    Patent number: 3967171
    Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.
    Type: Grant
    Filed: May 1, 1974
    Date of Patent: June 29, 1976
    Assignee: R. G. LeTourneau, Inc.
    Inventors: Aaron D. Friend, Hilmer C. Lindahl
  • Propulsion control system for electrically powered vehicles
    Patent number: 3953775
    Abstract: Propulsion control system for electrically powered vehicles, typically heavy duty off-road type work vehicles having electric motor driven wheels. In embodiment shown, power is supplied from direct current generator driven by internal combustion engine. Motor and generator field excitation is automatically varied responsive to selected machine operating conditions and improved means are provided to accomplish such variation. The provision and application of certain propulsion system parameters effects improved machine performance with minimum demand for operator skill and attention.
    Type: Grant
    Filed: March 23, 1973
    Date of Patent: April 27, 1976
    Assignee: R. G. LeTourneau, Inc.
    Inventors: Aaron D. Friend, Hilmer C. Lindahl