Patents by Inventor Donald E. Graham

Donald E. Graham 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: 4138630
    Abstract: Electrically operable switching circuitry is effective to energize, in response to the application of a control signal, a commutated electrical motor in a first direction for driving a member driven thereby through a travel stroke and to energize, in response to the removal of the control signal, the motor in a second direction for driving the member driven thereby through another opposite travel stroke and an electrical signal produced while the motor is in the run mode is effective to maintain the switching circuitry operated for motor energization. Upon motor stall when the member driven thereby has reached the end of a travel stroke, the electrical signal produced while the motor is in the "Run" mode terminates and the switching circuitry then operates to deenergize the motor.
    Type: Grant
    Filed: July 5, 1977
    Date of Patent: February 6, 1979
    Assignee: General Motors Corporation
    Inventor: Donald E. Graham
  • Patent number: 4105216
    Abstract: Electrical circuits responsive to a logic signal pair produced when the sprung mass of a motor vehicle is above a selected trim band and to another logic signal pair produced when the sprung mass of the vehicle is below the trim band produce respective sprung mass high and sprung mass low signals for a leveling system of the type operative to level the sprung mass of the vehicle within a predetermined trim band in response thereto. A delay circuit effective to inhibit the production of both the sprung mass high and sprung mass low signals for a predetermined time duration is provided to prevent unnecessary operation of the leveling system and respective accumulator circuits inhibit the production of each the sprung mass high and sprung mass low signals at the conclusion of respective predetermined accumulated periods of time.
    Type: Grant
    Filed: April 18, 1977
    Date of Patent: August 8, 1978
    Assignee: General Motors Corporation
    Inventors: Donald E. Graham, Paul J. Long, Jr.