GB190912112A - Improvements in Safety Brake Arrangements appplicable to Mine Cages and other Hoisting Apparatus. - Google Patents

Abstract

12,112. Smith, J. P., and Bruce, J. May 22. Catch gear of mine-cage type.-Safety suspending- apparatus for mine cages, lifts, &c. travelling in vertical or inclined shafts, comprises a roller adapted to be thrown into contact with the guides if the cage or vehicle is unsupported, the rotation of the roller winding a band upon itself so as to increase its diameter and arrest the cage gradually. In one form of the mechanism shown in Fig. 1, the frictional rollers 18 and reels 21 for the band are mounted in boxes 14 sliding horizontally in guides 13. Chains 31 connected to the hoisting- gear are passed around sheaves 30, carrying helical threads engaging recesses in the sliding boxes 14. In the event of the hoisting-cable breaking, springs rotate the sheaves 30, and the helical threads push the boxes 14 outwards until the rollers 18 engage the guides 1. The rotation of these rollers unwinds the bands 22 from the reels 21, and affords an increasing resistance to the downward movement of the cage. A ratchet-wheel on the shaft of the sheaves 30 prevents the boxes 14 from moving backwards. In another form of the mechanism, shown in Fig. 7, the shafts 56 of the rollers are mounted eccentrically in barrels 53 connected by links 48 to the draw-bar and controlled by a spring 64. If the cage is unsupported, the barrels 53 are rotated by the spring so as to bring the rollers into engagement with the side faces of the guides, and cause the bands to wind themselves thereon as in the first arrangement.