GB190802889A - Improvements in Safety Appliances for Mines. - Google Patents

Abstract

2889. Bennett, S. G. Feb. 10. Uverwinding, preventing. -A mine cage is automatically detached from the hoisting-cable in the event of overwinding by means of a special detacha b l e coupling, and the cage and its hoisting- shackle are independently supported in the e headgear. Fig. 1 shows the head-gear of the mine, Fig. 3 shows one.of a series of catches for supporting the cage, and Fig. 5 shows the detachable coupling and the eoacting parts of the head gear. The cage chains e are attached to a vertical rod c, Fig. 5, having a collar c' at its upper end. The hoisting- cable is attached to a rod b having a similar collar b<1> at its lower end. The collars b<1>, c' are normally retained by a split ring E, which closely envelopes the collars and slides within a cylinder d, to which is screwed a bell-shaped casting f. Fixed to the crossbeams at the top of the shaft is a plate K, provided with a central raised ring k<2> and with a pair of spring-pressed pawls l. When the cage rises too high in the shaft, the bell f forces back the pawls l and abuts against the ring k<2>. The spring h is then compressed by the continued motion of the hoisting- cable, and the spindles b, c rise until the collars b<1>, c' and their enveloping-ring E are clear of the cylinder d, the ring sections then falling apart and allowing the collars b<1>, c<1> to separate. The lower rod c then falls until a collar c<2> rests on a ring. G secured in the bell f, which itself rests on the pawls l. In order to provide additional security, the cage is supported on a series of pawls p which are mounted adjacent to the guides between the surface of the mine and the top of the head-gear. On each side of the head-gear are fixed guide-rails o of channel or other suitable section having slots cut in tbeir webs to allow a swinging motion of the pawls p about their pivots q. The pawls are formed with a tailpiece p<2> which prevents them from falling too far forwards and forms a connexion with a slotted vertical rod r by which the pawls may be swung out of action when necessary. On each side of the cage, a bar fitted with projections u<1> is fixed, and as the cage rises, the pawls p are pushed back, returning by gravity into their original position. The projections u<1> are so spaced in relation to the supporting- pawls p that one of the projections is always immediately above one of the pawls, thereby diminishing the shock due to the detachment of the cage. The bars on the cage are led into correct position by guide-rails widened out at their lower ends.