FLUID PRESSURE RELAY DEVICE AND ITS APPLICATION TO BRAKE SYSTEMS

摘要

1331626 Valves; braking systems WESTINGHOUSE BREMSEN-UND APPARATEBAU GmbH 21 Dec 1970 [20 Dec 1969] 60498/70 Addition to 1294987 Headings F2F and F2V A tractor multicircuit braking system incorporates a relay device 11 which serves as a trailer brake valve and acts to control the pressure in a trailer direct brake line 18 in response to the pressures in the circuits I, II of the trailer braking system and also in response to the pressure in a spring power auxiliary circuit III. A valve 3 controls the circuits I, II which incorporate respective storage tanks 2 and 5 and which respectively operate cylinders 4, 4SP1/SP for the front wheels and the rear wheels, and a manually operable valve 101 is included in the circuit III incoporating a storage tank 102 which valve 101 on actuation vents the cylinders 4SP1/SP. The relay device 11 includes two coaxially arranged relay pistons 53, 54 and the piston 53 consists of two parts 104, 105 connected together by a guide sleeve 57, and the relay piston 54 consists of two ports 60, 61. A double valve element 67 forms an inlet valve 56, 68 in conjunction with a valve seat 56 on the piston 53 and an outlet valve 66, 69 in conjunction with a valve seat 66 on the piston 64. The brake circuit I communicates with a chamber 73 above the relay piston 54, the second brake circuit II communicates with a chamber 76 below the piston part 105 and the valve 101 by way of line 103 communicates with a chamber 110 above the piston part 105, and this chamber 110 is normally charged with the pressure in the circuit III when the valve 101 is not actuated. The supply tank 102 communicates via a line 14 with a chamber 79 below the piston part 104 and a chamber 80 above the piston part 104 communicates with the direct trailer line 18. When the valve 3 is actuated air from tanks 2 and 5 enters cylinders 4, 4SP1/SP to brake the tractor and also enters chambers 73, 76 in device 11 and with either or both of the circuits I, II operative the pistons 53, 54 move relative to one another to cause inlet valve 56, 68 to open and outlet valve 66, 69 to close: air then flows from chamber 79 into chamber 80 and thence into line 18 to actuate the trailer brakes in advance of the tractor brakes. An equilibrium is established with the double valve 56, 68 and 66, 69 in a terminal position but when the valve 101 is actuated to vent the cylinders 4SP1/SP this equilibrium is disturbed and the inlet valve 56, 68 is opened until a pressure proportional to the resultant pressure decrease in chamber 110 is fed to the line 18.