GB169032A - Automatic compressed air brake controlled electrically and by compressed air, particularly for trains composed of several motor vehicles - Google Patents

Abstract

169,032. Rushen, P. C., (Knorr-Bremse Akt.-Ges.). June 26, 1920. Fluid-pressure. - Relates to compressed-air brakes which can be controlled either pneumatically or electrically and in which a main reservoir is connected to the brake cylinder both in electric and pneumatically controlled applications, so that the maximum braking pressure remains the same irrespective of the stroke of the piston and consists in connecting the electric application valve to a pipe which connects the main to an auxiliary reservoir. The main reservoir e is supplied through a reducing-valve d from the reservoir c, which is charged by the compressor. The auxiliary reservoir is supplied from the reservoir e through a reducing-valve g and a constriction h in the pipe g<1>. This constriction mav be provided in a non-return valve which permits a free flow of air out of the reservoir i. Air can flow past the usual groove in the triple valve piston k to the train-pipe p, which is normally not connected to the main reservoir through the driver's valve. If there are any trailer vehicles in the train, the auxiliary reservoirs on these are supplied by the train-pipe from the main reservoirs on the motor-vehicles. The constriction h prevents the occurrence in the auxiliary reservoir of a pressure sufficient to move the triple valve to application position when the reservoir is feeding the train-pipe. The brakes can be applied by energizing the valve l, thereby connecting the reservoirs e and i to the brake cylinder o through the double-check valve n, the supply from the reservoir i being substantial only if the constriction at h is provided in a non-return valve. The brakes can be released by energizing the valve m. The brakes can also be applied by reducing the train-pressure to actuate the triple valve k, the pressure in the reservoir i being maintained at the normal value through the connection g<1>. Release after a pneumatically-controlled application is obtained by admitting the full pressure in the reservoir e to the train-pipe through the driver's valve, to return the triple valves. To permit release of the brakes by train-pipe pressure control after an application by the valve l, the valve n is provided with a light spring urging it to the right, so that by initiating a pneumatically-controlled application after an electrically-controlled application the valve n is returned to the position in which it connects the brake cylinder to the triple valve through which the cylinder exhausts when the train-pipe pressure is restored.