GB1216116A - Fluid pressure control valves - Google Patents

Abstract

1,216,116. Fluid-pressure brakes; valves. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. 8 July, 1969 [10 July, 1968], No. 32816/68. Headings F2F and F2V. The brake valve of Specification 1,174,243 shown in Fig. 1, is modified by a loading magnet, Fig. 2, responsive to two or more variable quantities, e.g. speed and load of the vehicle to which it is fitted. The valve has an exhaust port 7 providing a seat for a throttling valve member 13 so as to set up a control pressure at an outlet 10, which is in permanent communication with a supply conduit 26 through a restrictive choke 25. The valve member is engaged by a cantilever leaf spring 14 which is loaded by a magnet 51 to determine the control pressure. Magnet 51 comprises a coil 18 carried by the spring and moving in a gap between a pole 52 and core 53. An end cap 55 supports the core and a permanent magnet 56. Additional windings 57 and 58 are provided to modify the field in accordance with the variable quantities. In a railway vehicle the coil 18 could be controlled by the driver and the windings 57 and 58 could modify the displacement of the magnet in accordance with the speed of the train and the weight of the coach. The permanent magnet can be replaced with an electromagnet excited with a constant current. In Fig. 3, not shown, the coil 18 reacts to the field of three windings (59), (60), (61). A core (53), Fig. 4, not shown, is displaceable between poles (52) and (66) by fluid pressure in a chamber (62). The braking system shown in Fig. 5 is disposed on trailer vehicle, e.g. a railway vehicle, incorporating the brake valve 78 to control a valve 76 and brake cylinder 77. Air from a reservoir 73 is supplied to valve 76 via a conduit 75, and a branch 79 feeds valve 78 to control valve 76 via a conduit 80. The coil 18 in valve 78 is controlled by the driver via a line 81 from, e.g. the driver's cab, a winding 82 is controlled over line 83 from a speed-sensitive device, which can be on the trailer, and the winding 84 is responsive to a transducer 86 in accordance with the load of the vehicle. In Fig. 6, not shown, three vehicles (88), (89) and (90) are controlled from a control point (91) by A.C. control signals which are converted to D.C. by rectifier bridges (92), (94) and (96) respectively located on each vehicle.