Patents by Inventor Graham S. Thexton

Graham S. Thexton 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: 7132808
    Abstract: A solid state series motor control includes first and second FORWARD DRIVE elements, first and second REVERSE DRIVE elements, first and second diodes, a current sensor, and a capacitance. The series motor control is configured to be interconnected with controlling logic or a processor, the field and armature of a series wound motor, and an external DC power source. The FORWARD DRIVE elements and REVERSE DRIVE elements can be IGBTs or similar semiconductors. The current sensor is configured to measure current passing through the motor armature. The capacitance is a combination of a line filter and source impedance reduction for IGBT switching. The solid state series motor control can control the speed and direction of a series wound motor using solid state components while maintaining the series connection of the armature and the field winding.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: November 7, 2006
    Inventors: Graham S. Thexton, Andrew S. Thexton
  • Patent number: 5875281
    Abstract: Direct current (DC) solid state series wound motor drives for hoist and crane applications. A microprocessor controlled electronic system is employed to control the speed, direction, acceleration and deceleration of a direct current DC solid state series wound motor drive for a hoist or a crane (bridge or trolley). The operation can be via an operator, radio remote, or computer communication link. The system requires a speed and direction command from the operator controls; it then configures the motor and varies the speed while offering certain protection circuits. The DC series wound motor drive includes a DC series wound motor comprising an armature and a series wound field that is supplied with DC voltage power from an external source. The DC voltage power supply can either be generated DC or rectified alternating current (AC). High speed insulated gate bipolar transistor (IGBT) switching elements are provided.
    Type: Grant
    Filed: July 24, 1997
    Date of Patent: February 23, 1999
    Assignee: Cableform, Inc.
    Inventors: Graham S. Thexton, John Aker