Patents by Inventor Mark H. Duckworth

Mark H. Duckworth 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).

  • Elevator system having microprocessor-based door operator
    Patent number: 4832158
    Abstract: An elevator system has a door operator with a door operator motor and a dedicated microprocessor for storing door open and door close cycles. The microprocessor initiates door open and close cycles responsive to external door open and door close commands. Preferably the microprocessor stores a plurality of door closed cycles in which the elevator controller selects one of the cycles when issuing a door closed command.
    Type: Grant
    Filed: December 3, 1987
    Date of Patent: May 23, 1989
    Assignee: Delaware Capital Formation, Inc.
    Inventors: Dennis J. Farrar, Mark H. Duckworth