Patents by Inventor Lawrence Hardy Mitchell

Lawrence Hardy Mitchell 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: 7462999
    Abstract: A permanent magnet brushless (PMBL) servo motor test apparatus and method allow testing of a motor in place. A set of static and dynamic tests is performed to determine proper motor operation of armature windings and rotor feedback devices. The test system of the present invention displaces the motor drive system. The test system comprises an armature driver, a feedback device input, and a system controller. The armature windings of the motor-under-test are driven in a polarity sequence according to a test sequence, whereby the rotor is driven in a series of rotations. Angle feedback is tested at a plurality of said rotations. Rotor velocity outputs are tested during said rotations. Armature current and voltage are determined at a plurality of said rotations and winding balance is tested. Said power switch is also operative to apply a voltage between the armature windings and the motor case to test for fault current flow.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: December 9, 2008
    Assignee: Mitchell Electronics, Inc
    Inventors: Lawrence Hardy Mitchell, Stuart Glen Mitchell
  • Patent number: 7005812
    Abstract: An apparatus that allows a non-standard brushless motor to be driven with a standard drive amplifier. The motor rotation angle signal from a custom feedback device is converted to a standard format for driving a standard drive amplifier. Operator display and keypad allow interactive format selection and motor parameter display.
    Type: Grant
    Filed: July 22, 2002
    Date of Patent: February 28, 2006
    Inventor: Lawrence Hardy Mitchell
  • Publication number: 20040036427
    Abstract: An apparatus that allows a non-standard brushless motor to be driven with a standard drive amplifier. The motor rotation angle signal from a custom feedback device is converted to a standard format for driving a standard drive amplifier. Operator display and keypad allow interactive format selection and motor parameter display.
    Type: Application
    Filed: July 22, 2002
    Publication date: February 26, 2004
    Inventor: Lawrence Hardy Mitchell