GB1363030A - Valve device for controlling operation of a brake cylinder - Google Patents

Abstract

1363030 Relay valves; rail vehicle compressed air braking system KNORR-BREMSE GmbH 21 Dec 1972 [28 Dec 1971] 59261/72 Heading F2F A rail vehicle compressed-air brake system includes a valve device 2 for controlling the operation of a brake cylinder 35 in response to pressure changes in a main air line 5. The device 2 comprises a control piston 3 separating a control chamber 4 from an admission chamber 6 connected to the line 5, the piston 3 being connected by a rod 8 to a valve packing 9 of a bleed valve 9, 14 which controls admission of compressed air from chamber 6 to a bleed chamber 12 which is connected to atmosphere via a valve 54 and is also connected via a duct 19 to a space 17 of a piston chamber; the packing 9 carries a valve tube 27 which is actuable to operate an inlet valve 38, 41 connecting an auxiliary reservoir to the brake cylinder 35 and an outlet valve 37, 38 connecting the brake cylinder 35 to atmosphere. Seat 14 of valve 9, 14 is formed on a control sleeve 13, on the external surface of which there bears a tappet 15 connected to an auxiliary piston 16 which separates space 17 from a space 18. The space 18 is connected via a duct 20 with chamber 6 and via a duct 25 and a shut-off valve 47 with chamber 4. The piston 16 is slidable over a duct 22 to connect this duct 22 with one or other of the spaces 17, 18, and the piston 16 has a valve seat 24 co-operable with a sealing ring 26 to form a shut-off valve 24, 26. Operation.-To brake the vehicle, a pressure drop is introduced into line 5, whereupon piston 3 moves upwardly to open valve 9, 14 whereby air flows from chamber 6 to the bleed chamber 12 and thence to atmosphere. Thus piston 3 is displaced upwards to an increased extent to move valve tube 27 to close outlet valve 37, 38 and open inlet valve 38, 41. Compressed air is thereby introduced into braking cylinder 35 and also into a chamber 51 and a chamber 43. The pressure in chamber 43 acts on a piston 44 to close a valve 47 cutting off chamber 6 from chamber 4, and increasing pressure from bleed chamber 12 acting in chamber 17 will move piston 16 to close valve 24, 26 and establish a throttled connection between line 5 and bleed chamber 12 via throttled connection 22. The control sleeve 13 is thereby allowed to move upwards to close valve 9, 14 and valve 54 is also closed by pressure building up in the chamber 51. As soon as braking pressure builds up in chamber 34 corresponding to the pressure drop in line 5, a piston 32 is moved downwardly to close inlet valve 38, 41.