Patents Assigned to Cableform, Inc.
  • 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