GB563591A - Improvements in or relating to safety devices for lifts, skips, cages and the like - Google Patents

Abstract

563,591. Catch gear for lifts. MACLEAN, G. R., and BARDER, H. Nov. 24, 1942, No. 16651. Convention date, Dec. 23, 1941. [Class 78 (iii)] A safety device for lifts, mine cages, and the like, comprises a cross-bar that extends between and slides on opposite guides in a lift shaft, and brake shoes pivoted to the cross-bar and to a lever pivoted in the lift cage, the arrangement being such that the shoes are held out of contact with the guides when the haulage cable is intact but are forced against the guides if the cable should break. The brake blocks are covered with a layer of soft, readily fusible metal. The cross-head 6, Fig. 1, is provided at its end with runners 7 that engage the shaft guides 3. The brake shoes 12 are pivoted at 10 to the runners 7 and also to links 16 which are pivoted to the sides of the cage 1. Springs 14 urge the brake shoes into contact with the guides 3, but a loop 5 of the haulage cable 2 passes through holes 20 in the ends of the links 16 and normally holds the brake shoes in the position shown. If the cable 2 should break, the shoes are swung downwards into contact with the guides by the springs 14 and by gravity, and when the fall of of the cage'is arrested, its weight keeps it in the arrested position. A canopy 23 with inclined sides is fitted to the cross-bar 6 to protect the cage from damage by a falling cable. Each brake shoe 12 is fitted with a pair of inclined brake blocks 25, Fig. 4, a curved leaf spring 25a arranged between them, and a body 26 of readily-fusible metal moulded over the blocks. When the brakes come into action, the friction between the guides 3 and the bodies 26 heats and melts the fusible metal, and the braking-friction is brought into action gradually.