GB284387A - Improvements in and relating to winders, haulages, lifts and the like - Google Patents

Abstract

284,387. British Thomson-Houston Co., Ltd., and Liddiard, H. W. C. Oct. 25, 1926. Electric plant.-In lift systems of the kind provided with an auxiliary electric motor for bringing the lifts accurately and automatically to rest level with a floor, the auxiliary motor is used automatically to vary the effective length of the winding rope through auxiliary apparatus independently of the main winding drum and hoisting mechanism. In one construction the winding ropes 3, 4, Fig. 3, pass round stationary sheaves 5, 6 and over travelling sheaves 7, 8 to a winding drum 9. The sheaves 7, 8 are moved independently in directions to cause the lifts to approach the floors by small electric motors 10, Fig. 6, which drive screws 14 engaging travelling nuts attached to the bearings 12 in which the sheaves are mounted. These motors are switched in after the main hoisting motor has been cut out and are de-energized when the lifts reach the floor. They are again switched in and reversed if the lifts overrun the floors. The sheaves 7, 8 may be connected in such a way that they move in opposite directions and are actuated by a single motor. In another construction the winding rope passes from the main drum 9, Fig. 9, under a sheave 36 attached to the lift 37, and then back to a small auxiliary drum 38 driven by an auxiliary motor 10. In a further construction the auxiliary drum and motor are mounted on the lift.