GB646824A - Improvements relating to fluid pressure transmission systems - Google Patents

Abstract

646,824. Fluid-pressure brakes. FIAT SOC. PER AZIONI, and BALDWIN, P. S. Dec. 30, 1947, No. 34742. Convention date, May 1, 1942. [Class 103 (i)] [Also in Group XXIX] A fluid-pressure actuator has at least one compound piston slidable as a unit in the cylinder 1, the compound piston comprising two metal parts 7, 8 and an inner expansible element 14 surrounded by a number of curved leaf-springs 15 which produce an axial force when the expansible element 14 is subjected to an internal pressure. The supply of pressure fluid to the actuator is automatically controlled by the valve 18. Pressure fluid is admitted via the inlet connection T through the passage B to the inside of the expansible element 14 and through the bore of the screwed plug 22, rubber ring 23 and grooves in the sides of valve piston 19 to the space M behind the compound piston part Y. At a predetermined pressure the valve piston 20 moves downwardly carrying with it the push-rod 21 thus allowing the valve piston 19 to seat on the rubber ring 23, thereby preventing the return flow of fluid from the space M behind the compound piston. The trapped fluid thus forms an unyielding base for the compound piston and the pressure fluid acting radially in the expansible element 14 produces an axial force on the brake shoe. When the pressure in the inlet T drops, the valve piston 19 is unseated by the action of the spring 28 through the push-rod 21 and the fluid in space M is released. Specifications 439,487 and 503,696 are referred to.