Patents Assigned to Doorlec Corporation/Corporation Doorlec
  • Patent number: 4422029
    Abstract: Disclosed is an instant reverse control circuit for a single phase, squirrel cage induction motor that has an exemplary use for opening and closing elevator doors. The motor has a running winding and a motor starting circuit comprised of serially connected start winding, capacitor, and centrifugal switch for deenergizing the start winding when the motor is up to running speed. The control circuit includes a relay operated, power reversing switch that supplies power to the starting circuit through an additional relay operated instant reverse switch. The instant reverse relay that operates the switch is connected in parallel with the starting circuit and its switch has a relay maintaining contact and a bypass contact. The bypass contact supplies reverse power to the start winding when the motor is to be reversed suddenly, such as to open a closing door that has struck an obstruction.
    Type: Grant
    Filed: May 19, 1982
    Date of Patent: December 20, 1983
    Assignee: Doorlec Corporation/Corporation Doorlec
    Inventors: J. T. Maurice Demers, Peter G. Stefanatos