Patents by Inventor Lutz Vietze

Lutz Vietze 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).

  • Measuring elevator hoistway position using audible signals
    Patent number: 5306882
    Abstract: A microphone 13 is provided upon the ceiling 4 of an elevator hoistway 3 and a loudspeaker 8 upon the top of an elevator car 1. A 9-16 kHz up-sweep is provided to the loudspeaker 8 and a sound signal is transmitted from the loudspeaker 8 to the microphone 13. The travel time of the sound signal is obtained by cross-correlating 53 the sound signal received by the microphone 13 with a reference signal. The reference signal is a received signal in a relatively noiseless environment. By multiplying the travel time of the signal by its velocity, the distance between microphone and loudspeaker is calculated 59. The hoistway temperature is measured 26 and used 57 in the absolute position calculation 59.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: April 26, 1994
    Assignee: Otis Elevator Company
    Inventors: Axel S. Gerwing, Lutz Vietze, Claudia M. Schmidt-Milkau