GB400157A - Improvements in or relating to elevator installations - Google Patents

Abstract

400,157. Lift cages. WESTINGHOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, U.S.A.-(Assignees of Arnold, E. E. ; Cathedral Mansions, Pittsburg, and James, H. D. ; 435, Locust Street, Edgewood, both in Pennsylvania, U.S.A.) Jan. 12, 1932, No. 900. Void [Abridged as open to inspection under Sect. 91 of the Acts, Jan. 13, 1932]. [Class 78 (iii).] An elevator installation, wherein the cage is operable between vertical guide rails, is provided with a service brake carried by the cage and comprising brake shoes which engage the rails to control the speed of the cage at any point. As shown in Figs. 2, 3, lined brake shoes 8, normally engaging non-lubricated guide rails 1, are mounted on eccentric shafts 16 connected by links 17, 19, to a piston 21 mounted in a cylinder 22. When the main control circuit is closed, a valve 12 is opened by a magnet 32 and allows fluid to flow from a pressure tank 11 to the cylinder 22 and actuate the piston 21 to remove the shoes 8 from the rails 1 against the action of springs 24. The tank 11 is supplied from a storage tank 28 by a pump 26 driven by a motor 27 which is controlled by a pressureresponsive switch 31 to maintain a constant pressure in the tank 11. Lateral oscillation of the cage is prevented by rollers 41, 42, Fig. 4, which are mounted on a bracket 43, pivoted on a frame 44 secured to the cage, and are maintained in engagement with the rails by an adjustable spring 46 tending to rotate the bracket away from the horizontal. Longitudinal movement of the cage is prevented by a roller 49 which is mounted on a bracket 51x, pivoted on the frame 44, and held against the edge of the rail by a spring 53. Fig. 11 shows a modification in which rollers 113, 114, 121, co-operate with a channel guide rail 112. In a modification Fig. 8, the brake shoes 71 are normally held against the rails by springs 75 engaging arms 73 on shafts 72 supporting the shoes, but are disengaged by a corrugated member 78 actuated by fluid-pressure generated when required from a device 81, Figs. 9 and 10. This device comprises a chamber 83 which is provided with resilient corrugated walls 85 compressed by a magnet 96 depressing a disc 82 when the brake circuit is closed, fluid pressure then being transmitted to the member 78 through a pipe 89. The application and release of the brakes is controlled by spring-loaded valves 91, 92, and the pressure applied to the member 78 is automatically varied by a resistor 101 in the magnet circuit 102, 103, associated with a governor 104, sections of the resistor being inserted in the circuit as the speed of the cage diminishes so as to bring the cage smoothly to rest.