GB586294A - Improvements relating to colliery winding and like machinery - Google Patents

Abstract

586,294. Fluid-pressure controlled brakes. WILD & CO., Ltd., M. B., and BATTY, A. W. H. Sept. 6, 1944, No. 17049. [Class 103 (i)] [Also in Group XXX] In a winding drum brake mechanism of the kind in which brakes co-operating with drums are applied by weights and released by hydraulic or pneumatic means, additional hydraulic or pneumatic means counteract in part the brake applying weights and are put into and out of action by valve mechanism. As shown the winding drums a are on a common shaft and clutching means (not shown) are provided so that both drums may rotate together or alternatively one drum may remain stationary while the other rotates. Brake shoes b are applied by weights c and are released by the action of hydraulic or pneumatic pistons d and cylinders e. The weights c are counteracted in part by cylinders n driving pistons m secured to the pistons d. The supply of fluid to the cylinders n is controlled by a valve s the setting of which is determined by the relative position of levers u, t which also operate respective isolating valves q controlling fluid supply to the cylinders e. In operation when the levers u, t are set to position the isolating valves q to supply fluid pressure to both the cylinders e, the valve s is set by a linkage y coupled to the levers u, t to supply fluid to the cylinders n. Normal control of the brakes is effected by the pistons d under the control of a valve p and lever v. When one drum is to remain stationary the respective lever u, t is manipulated to cut off pressure from the respective cylinder e and due to the linkage s this causes pressure to be cut off from both cylinders n so that the full force of the respective weight c is applied to the brake of the active drum The force exerted by either piston m may be half the corresponding weight c.