GB770835A - Distributor valve assembly - Google Patents

Abstract

770,835. Fluid-pressure brakes. WESTING- HOUSE BRAKE & SIGNAL CO., Ltd. June 16, 1955 [June 17, 1954], No. 17347/55. Class 103 (1). [Also in Group XXIX] In a driver's brake valve for a fluid pressure installation for a lorry or tractor trailer system having two independent fluid pressure circuits, two independent distributer valves operated by a single control member coupled to the distributer valves by means of a transmission, the ratio of which is controllable by the driver, permit the two fluid pressure circuits to be placed in communication with the atmosphere or with a source of fluid under pressure. In the embodiment illustrated, applied to a lorry or a tractor-trailer unit, a double body c of the distributer valve assembly comprises two cylinders 1, 1<SP>1</SP> forming, with the pistons 5, 5<SP>1</SP> two delayed reaction chambers 2, 2<SP>1</SP> connected by two small calibrated passages 32, 32<SP>1</SP> with chambers 3, 3<SP>1</SP> in communication with the circuits to be supplied. Chambers 4, 4<SP>1</SP> receive compressed air from reservoirs and flow of air from chambers 4, 41 to chambers 3, 31 is controlled by double distributer valve members 8, 8<SP>1</SP> and from chambers 3, 3<SP>1</SP> to atmosphere via tubes 6, 6<SP>1</SP> in pistons 5, 5<SP>1</SP>; a cover c<SP>1</SP> enclosing the control mechanism. In operation, when the driver depresses control rod 29, the floating lever 16 which, as a result of eccentricity of rod 29 relative to the mid-point of lever 16 and the more feeble resistance offered by the weaker right hand return spring 10<SP>1</SP> causes the right hand piston to move downwards before the other. This effect is not impeded at the commencement of the operation by the effect of biasing spring 20 since a lost-motion connection is provided between levers 16 and 17. Thus the right hand distributer valve is constantly in advance of that of the left whatever the relationship established for the final pressures of the two circuits. When the compression of the spring 13 is sufficient to bring about the opening of inlet valve on left hand distributer valve, compressed air will be supplied to the corresponding circuits and the pressures will develop in the two circuits depending upon (1) the compression of the two returning springs 10, 101; (2) the eccentricity of controlrod 29; and (3) the position of axle 22 of lever 17 which may be controllable by the driver by means of control member 25. By adjusting the position of axle 22, the driver can, at any time, distribute the braking to two axles on the same vehicle or to a tractor and trailer in accordance with the load it carries.