GB236905A - Elevator safety appliances - Google Patents

Abstract

236,905. Waygood-Otis, Ltd., (Assignees of Lindquist, D. L.). July 11, 1924, [Convention date]. Safety retaining mechanism. -A brake on the cage is applied to a stationary guide rail in case of excessive speed, insufficient retardation on approaching terminal points, and over-travel. The brake comprises a pair of shoes 69 which are supported by links 70 pivoted to jaw members 61, 62. Springs 79 are placed between the shoes and jaw members. The jaw members are connected by pivots 64 to fixed members 58 attached to a beam 21 secured to the cage bottom. Springs 67 are placed between the members 61, 62 and 58. The brake shoes are actuated by rods 60 which are urged downwards by springs 96 and rest on cams 98 mounted on shafts 99. The shafts 99 are geared together and one f them is geared to a shaft 104 provided with an arm 108 to which is connected one end of a rope 38. The .other end of the rope is attached to a hitch 26 on an endless rope 25 which is held normally in a releasing carrier 27 on the cage. The rope 25 passes over a sheave driving a centrifugal governor and between pivoted jaws 28, 29. An arm 31 on the jaw 28 is engaged by a spring-pressed catch 33 and connected to the governor by a link 32. When the cage overspeeds, the governor closes the jaws on the rope 25 and stops its movement. As the cage continues to move, the hitch 26 is withdrawn from the carrier 27 and the shaft 104 is rot'ated, thereby causing the application of the shoes 69 to the guide 16. When the shaft 104 has been turned through an angle of 90‹, the rope 38 draws the rope 25 through the jaws 28, 29 as the latter jaw can move horizontally against the resistance of the spring 37. The brake is applied automatically if the speed is not reduced sufficiently on approaching the landing 42 by a governor-controlled cam 41 projected into the path of a lever 112 mounted on the cage. A link 110 connects the lever 112 and arm 108. The cam 41 is secured to a rod 43 slidably mounted in supports 44 and connected by a toggle linkage 45 to an abutment 46. A link 47 connects the toggle with a lever 48 actuated by a governor 23. An endless rope 39 attached to the cage drives the governor. The cam remains in the path of the lever 112 if the speed is insufficient'ly reduced. Spring catches 49, 50 on the link 47 co-operate with latches 51, 52 respectively on a stationary support. If the car over-travels the landing 42, the brakes are applied by the engagement of the lever 112 with a cam 24 mounted in the well. The cam is pivoted so that it will be turned out of the path of the roller 116 on the lever 112 as the cage rises. The guide rail 16 is increased in thickness above the point 19 so as to apply the brakes if the cage overtravels on the upward run. In order that the slippers 85 of the guides 17, 18 shall always engage the rail 16, they are carried by slidable rods and are acted on by springs 89. A similarlymounted plate 90 is applied by springs 92 to a third face of the rail.