GB426720A - Regulator for vacuum or compressed air brakes, applicable to fast trains and to goods trains - Google Patents

Abstract

426,720. Fluid - pressure brakes. HOUPLAIN, G. E., 8, Rue de Belloy, Paris. Oct. 4, 1933, No. 27356. Convention date, Oct. 4, 1932. [Class 103 (i)] A device for preventing skidding of the wheels of vehicles during braking comprises a centrifugal device driven by the wheels and adapted if the speed of rotation falls to a low value first to cut off the supply of air to the brake cylinder and then to open a relief valve to reduce the pressure. In systems comprising a first and a second cylinder on a vehicle of which the second cylinder comes into operation after the first, the device is associated with the second cylinder. Fig. 2 shows a device for vacuum brakes mounted on the end of the brake cylinder 40 which is shown of relatively reduced size. Chambers 10, 11 are connected respectively to the main pipe at 12 and to the upper chamber of the brake cylinder 40. A ball-valve 14 disposed in a cavity in a slidable member 22 controls communication between the chambers 10, 11. The member 22 is coupled for left to right movement by a one-way ball-clutch 27 to a rod 28 on which the centrifugal device acts through lever 32. A valve 15 is held open by the engagement of piston 41 with the rod 20 when the brakes are released so that both cylinder chambers are then connected to the main pipe and thus to the vacuum source the one through passage 13 and chamber 10, and the other by way of chamber 11, valve 14 and chamber 10. When the brakes are applied the valve 15 is prevented from closing by the extension 25 of member 22 as long as the speed of wheel rotation is above a predetermined value but if the speed falls considerably the movement of the lever 32 permits the spring 31 to move the members 28, 22 to the right so that the valve 15 is closed by a spring 16 cutting- off the air supply to the lower cylinder chamber while the ball-valve 14 is unseated to connect the chambers 10, 11 thus permitting air to flow to the upper cylinder chamber to reduce the braking pressure. When the wheel speed again rises the valve 14 is re-seated but the valve 15 remains closed. A similar construction adapted for a single-chamber compressed air brake is also shown, the valve 14 being replaced by a lift-valve that connects the brake cylinder to atmosphere.