GB487526A - Improvements in or connected with fire escapes - Google Patents

Abstract

487,526. Lowering-appliances; brakes. LONGWORTH, J. R. March 10, 1937, No. 6998. [Classes 78 (ii) and 78 (v)] [Also in Group XXXIV] In fire-escapes of the type comprising a casing housing a shaft on which is mounted a grooved rope pulley, a coaxial gear, a fixed brake drum and revolvable support arms adapted to be rotated at high speed through the multiplying gear when the rope rotates the pulley during lowering of a load, such arms carrying and guiding radially movable segmental brake blocks connected together by springs and by toggle-links, the blocks i embrace the revolving arms h by long tongue and groove slide connections h<2>. One link l of each pair of toggles carries a mass l<1> which assists the blocks i in their centrifugal motion when the speed becomes excessive. Fig. 3 is a cross-section showing the general layout. The serrated pulley g is loose on a fixed shaft d and has an integral internally-toothed wheel g<2> which engages pinions b<2> loose on shafts b<3> fixed to a partition b which is always stationary relative to the back plate a of the casing, being riveted thereto through distance sleeves c. The pinions b<2> mesh with a central wheel h<1> integral with the arms h. The blocks i are fitted with a friction covering i<1>. The shaft d is held to the casing front f by a screw f<1> which also serves to force oil placed in the screw hole through a passage d<3> into an oil annulus h<2> The rope is guided in and out of the casing by rollers m<2> separated by a partition.