×

Elevator controller

  • US 4,979,593 A
  • Filed: 08/17/1988
  • Issued: 12/25/1990
  • Est. Priority Date: 08/26/1987
  • Status: Expired due to Fees
First Claim
Patent Images

1. An elevator controller comprising:

  • trolley wire disposed along a hoistway of an elevator to supply electric power from a machine room of the elevator to an elevator car and to transmit a safety related condition signal from the elevator car to the machine room;

    a radio system which transmits information signals including an operating condition signal between the machine room and the elevator car;

    a transmitter-receiver of said radio system in the machine room;

    said transmitter-receiver having a receiving amplifier and a transmitting output circuit;

    an electric motor for moving the elevator car; and

    means for generating a car position signal in accordance with rotation of the electric motor,the car position signal representing distance between the elevator car and the machine room as the elevator car travels along the hoistway; and

    means for adjusting gain of said receiving amplifier and means for adjusting output of said transmitting output circuit in response to the car position signal whereby the radio system information signals are varied in accordance with the distance between the elevator and the machine room to avoid saturating receiving circuits.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×