Julio Dario Ramos

US Patent:

59693037, Oct 19, 1999

Filed:

Mar 17, 1998

Appl. No.:

9/041999

Inventors:

Gerard G. Piserchia - Emerson NJ
Julio C. Ramos - Lake Hiawatha NJ

Assignee:

Inventio AG - Hergiswil NW

International Classification:

B66B 128
H02P 312

US Classification:

187297

Abstract:

An emergency stop circuit for an elevator drive includes an emergency stop control (7) that selectively varies the current flowing in a field winding (4) of a direct current drive motor (M). During an emergency stop, the motor (M) operates as a generator and has an armature winding (1) loaded with a braking resistor (9) to apply a voltage, depending on the direction of movement of the elevator car, either by a first switch (10) and a second switch (11), or by a third switch (12) and a fourth switch (13). The switches (10, 11, 12, 13) are connected as an H-bridge between the windings (1, 4) and are controlled by the emergency stop control (7) depending on the deceleration required by the elevator car, for example by pulse operation depending based upon a preset deceleration value and a measured deceleration value from a deceleration sensor (14) mounted on the car.