LIFT DOORS AND METHOD OF DOOR CONTROL Russian patent published in 2000 - IPC

FIELD: mechanical engineering; crane units. SUBSTANCE: proposed installation has device with three-phase induction motor to set into motion lift doors, control device and device for generating pulses in process of door movement. Control device is made to control doors according to generated pulses. Signals to control motor are supplied in check points according to schedule defining dependance of speed from distance covered by lift door and preset in per cents. Total distance covered by lift door in one direction is measured by counting number of pulses generated in process of door movement between extreme points at constant speed. Number of counted pulses is normalized and expressed in per cents, 100% being total distance. Proposed installation has no unreliable and difficult-to-adjust mechanical units. Speed and power of motor are controlled by electronic system. EFFECT: increased efficiency of control, reduced cost. 15 cl, 5 dwg