US 4,263,988 A · Speed control system for a motor

Abstract

A speed control system for an elevator motor, comprising a D. C. motor for driving an elevator, a device which generates a speed command signal for the elevator, a speed dynamo which generates a speed signal corresponding to a speed of the elevator, a speed control device which adjusts an applied voltage to the motor according to the speed deviation between the speed command signal and the speed signal, an emergency stop device which subjects the elevator to braking when the speed deviation has exceeded a predetermined value, and a blind sector device which provides an output when the speed signal has exceeded a predetermined value and which negatively feeds it back to the speed control device.

Claims20

Dependent claims

A speed control system for an elevator comprising:

a motor for driving an elevator;
a magnet brake for holding said motor in a stop state;
means for generating a speed command signal for said elevator;
means for generaging a speed signal corresponding to a speed of said elevator;
speed control apparatus which controls a speed of said motor according to a deviation between the speed command signal and the speed signal;
and
a blind sector device which is electrically connected between said speed signal generating means and said speed control apparatus and provides a feed-back signal which suppresses an output of said speed control apparatus when said speed signal exceeds a predetermined value which is set to be higher than a rated speed of the elevator.

4 more elements

Dependencies are inferred from the claim text.

Speed control system for a motor

Life of this patent

Speed control system for a motor

Life of this patent

Abstract

Claims20