GB1397372A - Valve device for supplying fluid to a plurality of output lines - Google Patents

Abstract

1397372 Pneumatic control circuits KNORRBREMSE GmbH 14 Feb 1973 [14 Feb 1972] 7374/73 Heading F1P [Also in Division F2] A valve device comprising flow control valves 6, Fig.1, connected to a supply line 2 and having outlets 3, 4, 5, has by-pass paths 7 which include throttles 8 in series with non-return valves 9. A control line 10 is provided. In operation, compressed air is supplied to the line 2 with the three circuits at atmospheric pressure and air flows round the valves 6 through by-pass paths 7 so that some filling of levies 3, 4, 5 occurs. The valves 6 are constructed to open when fluid pressure is present at the control inlet and the fluid outlet. Thus pressure build-up due to the throttles 8 promotes opening of the valves. If the compressed air supply fails, air can flow unthrottled from one line to another until the circuit pressure falls below the opening pressure of valves 6. If one line develops a leak, the valve 6 in that circuit will close when the pressure falls to atmospheric and the loss of compressed air through the by-pass line 7 will be small. The two intact lines will function normally. Fig.2, (not shown), illustrates a modified circuit. Fig.3 shows a four-line system with by-pass valves 22, 23, 24, 25, the valves 22, 23 incorporating shut-off valves 32. The latter ensure that lines 17, 18 are filled first when compressed air is supplied through line 16. Fluid passes through by-pass lines 28 until pressure build-up opens valves 22, 23 and with them valves 32. Flow now occurs through by-pass lines 31 until pressure build-up causes valves 24, 25 to open. Fig.5 shows a construction of the valve device in which two by-pass valves 42, 43 are illustrated. Operation is as follows. If the lines 17, 19 are at atmospheric pressure, compressed air from pipe 16 flows through bores 49, 50 into chambers 47, 48 below valve pistons 42, 43. Sealing ring 63 acts as a non-return valve. The pressure built up below piston valves 42, 43 is insufficient to open them against springs 44. From chamber 47 air flows through an annular gab 51, under a sealing ring 54 and through a throttling duct 56 into a bore 55 and line 17. The sealing ring 54 acts as a non-return valve. Pressure builds up in the line 17 and eventually the valve piston 42 is lifted so that there is a free flow of air into line 17. Air cannot flow from chamber 48 under piston 43 because of sealing ring 62. However, when piston 42 has been raised air passes through bores 60, 59, 61 past the ring 54, which acts as a non-return valve, through throttling duct 56 and into chamber 55 and line 19. Pressure builds up in line 19 and raises piston valve 43 so that there is unrestricted flow into line 19. The other half of the valve operates in the same manner.