Patents Examined by Robert F. Nappi
  • Measuring elevator car position using ultrasound
    Patent number: 5223680
    Abstract: Two ultrasonic transducers are provided, one upon the ceiling of an elevator hoistway and the other one the top of an elevator car for measuring the time for an ultrasonic signal to travel from one transducer to another and return for treasuring elevator position.
    Type: Grant
    Filed: June 3, 1991
    Date of Patent: June 29, 1993
    Assignee: Otis Elevator Company
    Inventors: Claudia M. Schmidt-Milkau, Klaus Disterer, Rolf E. Hanitsch