Patents by Inventor David J. Rado

David J. Rado 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 leveling signal error and correction
    Patent number: 4520904
    Abstract: In an elevator that has a position indicator that indicates through separate indication signals if the car is above, at, or below floor level, the position indicator is checked prior to and during the approach to the floor for a stop, and if an incorrect indication is sensed, the error is stored. The stored error and the other indications are used during the approach to slow and stop the car and open the doors.
    Type: Grant
    Filed: November 9, 1983
    Date of Patent: June 4, 1985
    Assignee: Otis Elevator Company
    Inventors: David J. Rado, Steven D. Coste