Patent GB-936730-A (GB)
Title: Improvements in or relating to a braking system for rail vehicles
IPC: B60T13/60
Filed: 1960-06-22
Abstract: 936,730. Fluid-pressure brakes. KNORRBREMSE G.m.b.H. June 22, 1960 [June 25, 1959], No. 21903/60. Class 103 (1). A braking system for rail vehicles equipped with an automatic compressed air brake and an automatic vacuum brake, comprises a valve having change-over members 93, 97, 99, 101, in one position of which the valve controls the automatic compressed air brake through relay valve 13, and in the other position of which the valve controls the automatic vacuum brake through relay valve 43. Control of vacuum-brake, the apparatus is shown in the brake release position. Compressed air pipe 1, relay valve chamber 29 and reservoir 135 are fully charged and vacuum exists in pipe 3, relay valve chamber 55, above pistons 107, 109 controlling valves 93, 97, 99, 101 and in chamber 75 of the driver's valve. The main air pipe 5 is vented by a previous brake application and reservoir 169 and chamber 127 are vented via valve 167. Valves 35, 91 are opened by lever 95 when driver's valve is operative, vacuum existing in chambers 69, 59, 85 via valve 91, 93, and chamber 83 is vented via valve 99. Atmospheric pressure obtains in relay valve chamber 33, 37 via valve 35, and relay valve 43 charges vacuum train pipe 7 and chambers 171, 175 of triple valve 117, a spring 159 holding valve 147, 149 open to vent brake cylinder 153. Brake application.-Valve 73, 77 is opened by handle 61 to vent chamber 69 until the loss in vacuum in chamber 85 and spring 89 reclose the valve. The drop in vacuum in relay valve chamber 59 opens valve 45, 47 to vent vacuum train pipe 7 for brake application. The train pipe pressure acts in chamber 171 to raise piston 173 to close valve 147, 149 and open valve 149, 151 to charge brake cylinder 153 from reservoir 135, pressure in chamber 155 moves valve 117 to a lap position. With no vacuum brakes.-Vacuum pipe 7 is vented by vacuum'brake application; vacuum supply to pipe 3 is stopped and chambers 175, 171 vented via valve 177; springs 111 changeover valves 93, 97, 99, 101 to connect relay valve 13 to the driver's valve instead of relay valve 43. Compressed air in pipe 1 passes via valve 97 to chamber 75 and via valve 71, 73, opened by spring 89, to chamber 69 until pressure in chamber 83 connected to chamber 69 via valve 101, moves piston 79 to close valve 71, 75, chamber 85 being vented via valve 99. Chamber 37 is charged from chamber 69 via valves 91, 93 to open valve 19, 25 and charge pipe 5 and cylinder 33 from pipe 1 until piston 15 is raised to its original position, chambers 119, 127 being charged from pipe 5. Brake application.-Valve 73, 77 is opened to vent chamber 69 until reclosed by loss of pressure in chamber 83. Relay valve 13 is operated to open valve 21, 27 to create a pressure drop in pipe 5 causing piston 125 to rise and open valve 149, 151 to charge brake cylinder 153 until valve 149, 151 is reclosed. On brake release, chamber 69 is charged via valve 71, 73 and on recharging of pipe 5, piston 125 is lowered to vent brake cylinder 153 via valve 147, 149. To change back to control of vacuum brakes, the pipe 5 is completely vented, chamber 127 is vented via valve 167 and pipe 3 evacuated, the valves 93, 97, 99, 101 being changed-over and regulation vacuum in chamber 59 of relay valve 43 creates vacuum in pipe 7, chamber 171 and reservoir 179.