GB691982A - Improvements in braking control systems for winders and the like - Google Patents

Abstract

691,982. Hydraulic brakes for hoist gear. BRITISH THOMSON-HOUSTON CO., Ltd., WILD & CO., Ltd., M. B., BATTY, A. W. H., LIDDIARD, A. H. C., and McVEIGH, E. M. C., [Representatives of LIDDIARD, H. W. C.]. Sept. 27, 1951 [Nov. 6, 1950], No. 27061/50. Class 103 (i). A fluid-pressure control system for winding drum brakes of the type normally applied by a weight 2 or a spring, comprises a pressure release system for the brake applying cylinder 3 which operates in such a way as to provide a rapid take-up of slack in the brake rigging and thereafter gives a degree of braking when the winding machine is raising loads which is more sensitive than that provided for lowering loads. Fluid pressure, preferably oil pressure, is supplied to the cylinder 3 by way of inlet 5 and the operator's control valve 4, which are of known type. On release of the brakes, the fluid exhausts into a chamber 6 closed by a throttle valve 7 which may be adjusted by a piston in a cylinder 14 to such a volume that it permits any slack in the brake rigging to be rapidly taken up, further release of the brakes being controlled by the valve 7. The valve 7 is controlled by a pressure-operated device 8 supplied by a displacement pump 9 from a storage reservoir 13, the pump being driven by the winder so as to give full operating pressure at a fraction of full speed when raising loads, excess pressure being by-passed by a relief valve 12. A non-return valve 15 is arranged to pass oil when the winder is lowering loads so that the pump and pipework are kept full of oil for both directions of rotation. Member 11 is a second adjustable by-pass which allows pressure in cylinder 8 to fall when the winder is stationary. Member 10 is a further throttle valve dependent on the position in the wind and does not form part of the invention.