Patent GB-616145-A (GB)
Title: Improvements relating to triple valves for use with compressed air braking systems on railway vehicles
IPC: B60T15/30
Filed: 1946-08-29
Abstract: 616,145. Fluid-pressure-operated brakes. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Aug. 29, 1946, No. 25928. Convention date, Dec. 9, 1943. [Class 103 (i)] The application and release movements of triple valves of compressed air brake systems are initiated by the one and the other of a pair of pilot valves arranged to be selectively operated by the single armature of a magnet by the energization of the one or the other of two windings which may be effected by the provision of only two line wires by the use of rectifiers. The pilot valves may operate relay valves which respectively vent the brake pipe and auxiliary reservoir sides of the main valve piston to atmosphere to operate the piston. Fig. 1 shows a triple valve of standard type except for the provision of passages 7, 8, 9 and the parts in the base 6 including relay valves 18, 19 controlled by a magnet valve comprising an armature 2 which is moved in one direction or the other to open valves 4, 4<SP>1</SP> by the selective energization of two coils 3, 3<SP>1</SP>. By the use of rectifiers 5 only two line wires are required, the current being sent in one direction or the other to energize the coils respectively. Passage 7 extends from the seat of the slide valve 11 to the peripheral chamber around the seat of the relay valve 19. Passage 9 extends from the peripheral chamber of relay valve 18 to the brake pipe connection 16. Passage 14 extends from the slide valve seat to the accelerating bulb 15 and passage 8 extends from passage 14 past a non-return valve 20 to the valve 4 and to the underside of valve 18. A restricted passage 26, 27 connects the two sides of each valve 18, 19. Normally, therefore, brake pipe pressure exists on both sides of valve 18. To effect a brake application, coil 3 is energized to open valve 4, thus venting the under-chamber of valve 18 which then moves down to connect the brake pipe to atmosphere through passages 9, 24. The consequent movement of slide valve 11 by piston 12 connects the brake pipe to the bulb 15 and thus also to passage 8 and the lower chamber of valve 18 which is then reclosed by the spring 23. The brake pipe continues to vent, however, through valve 4 by way of passages 9, 26 and also passage 8 until the coil 3 is de-energized to close this valve. With the slide valve 11 in a braking position, the passage 7 is open to the slide valve chamber so that when to release the brakes, the valve 41 is opened by energizing the coil 3<SP>1</SP>, the valve 19 is moved downwards to vent the auxiliary reservoir by passages 7, 28, thus effecting return of the slide valve to release position. The triple valve shown in Fig. 2 includes two charging grooves 38, 39, only one of which extends to the inner end of the piston chamber for a purpose described below and through which air from the brake pipe connection 50 flows through chamber 53 to the auxiliary reservoir connection 51. A quick-inshot valve 68 is normally held open by the pressure in chamber 53 acting on piston 62 through passage 63. The brake cylinder is thus open to atmosphere through passage 64, 67, valve 68, passages 69, 70, 71 and a " mountain-plain " baffle device 66 which may be set for level or hilly track by a cock 65. With the " passenger-goods " cock 42 in the " passenger " position shown, the valve 68 is byepassed through passages 37, 36 and an additional exhaust port 32 is connected to the brake cylinder through passages 72, 73. The accelerator bulb 15 is connected to exhaust port 32 by passages 33, 34, 35. Energization of the coil 3 to apply the brakes opens valve 4, thus venting the upper chamber of relay valve 18 which is connected to the brake pipe by port 26 in the valve and passages 57, 56, 55. Valve 18 is thus unseated and vents the brake pipe to atmosphere by passage 57 and port 24, thus effecting movement of piston 12 with the main and graduating slide valves 11, 45 to application position in which the brake pipe is 'connected to bulb 15 by passages 55, 34, 33 and the auxiliary reservoir to the brake cylinder by passages 51, 54, chamber 53, slide valve passage 83, passage 69, thence through cock 42 by passages 36, 37 and at first also past valve 68 until the cylinder pressure acting on piston 87 is able to overcome the pressure in the chamber of piston 62 which has been cut off from chamber 53 by the slide valve 45. The valve 68 then closes. When the coil 3 is deenergized, the valve 18 re-closes. In the application position of the slide valves, the passage 60 from the relay valve 19 is connected to the exhaust port 32 by passages 70, 35. The passage 58 from the valve 19 is connected to the valve chamber 53, the pressure in which normally equalizes through port 27 to the back of the valve 19 and the passage 59. Thus, when to release the brakes, the passage 59 is connected to atmosphere by energizing the winding 3<SP>1</SP> to open the valve 4, the valve 19 is unseated and connects passage 58 and chamber 53 to passage 60, thence to exhaust port 32. The piston 12 with the slide valves is thus returned to the release position shown. If while the winding 3<SP>1</SP> is energized, the triple valve fails to be operated, the pressure in the brake pipe which is being recharged will exceed that in the chamber 53 and this pressure difference acting on a diaphragm 43 and projections 90 will unseat the relay valve 19 and so effect the venting of the chamber 53 to return the piston 12 and the slide valves. According to the Specification as open to inspection under Sect. 91, charging of the auxiliary reservoir in the case of the construction shown in Fig. 2 is normally effected through both of the grooves 38, 39, but if as may occur at the forward part of a train the pressure in the brake pipe acting on piston 12 exceeds that in the chamber 53 sufficiently to overcome a spring-stop 92, the piston is moved to cut off the groove from the chamber 53. The " mountain-plain " brake cylinder exhaust device 66 comprises two sets of baffle plates 72, 73, Fig. 6 (Cancelled), separated by a spacer 95 having ports in register with ports in a container tube 99. According as the cock 65 is open, as shown, which is the " plain " position, or closed, the cylinder exhausts through both sets of plates and ports 74, 138 or only through the lower set. The sets differ and to prevent the device being assembled with the tube 99 the wrong way round, the tube has a projecting part 94 which if it is in the upper position prevents the casing 98 from being screwed into the main body of the triple valve. In another construction, Fig. 9 (Cancelled), the accelerating chamber 107 is formed in the main body of the device and is permanently open to atmosphere by a restricted port 108. The piston 12 operates the main slide valve 11 with lost motion by a spring buffer 103, 141. Normally, the piston 12 is held by a spring stop 102 in the position shown so that air flows from the brake pipe to the auxiliary reservoir by passages 50<SP>1</SP>, 115, piston grooves 38, 39, slide-valve chamber 53, passages 110, 132, 51. The brake cylinder is open to atmosphere by passage 64<SP>1</SP>, quick-inshot valve 105 and passages 111, 112, 113. The valve 105 being held open by the piston 62<SP>1</SP> acted on by auxiliary reservoir pressure through passage 114. When to apply the brakes the winding 3 is energized to open the valve 4 and thus the relay valve 18, the brake pipe is vented to the chamber 107 by passages 116 ... 119, 107<SP>1</SP>. The piston and slide valve 45 are thus moved to an intermediate position in which the brake pipe is still connected to the chamber 107, but by passages 116, 117, 138, 125 instead of by the relay valve 18 which may now be closed consequent upon the de-energizing of the winding 3. The continued fall of brake pipe pressure causes the piston 12 with the slide-valves to move to the extreme right-hand position in which the brake pipe vents to the brake cylinder through passages 116, 117, 126, non-return valve 1061, valve 106 and passage 64<SP>1</SP>. The brake cylinder is also supplied by the auxiliary reservoir through passages 51<SP>1</SP>, 110, valve chamber 53, passages 127, 111, valve 105, passage 128 and passage 641. When the brake cylinder pressure acting on piston 87<SP>1</SP> is sufficient to overcome the pressure acting in the chamber below piston 621, which is now shut off from the auxiliary reservoir, the valves 105, 106 close and the supply to the brake cylinder continues only through the passage 128. When an emergency application is made, the valves 4, 18 are maintained open and the brake pipe continues to vent to the chamber 107. When to release the brakes the winding 3<SP>1</SP> is energized to open valves 41, 19, the slide-valve chamber 53 is vented to atmosphere by passages 129, 130, 130<SP>1</SP>, thus causing the piston and valves to move to the left. As in the form shown in Fig. 3, a diaphragm 88<SP>1</SP> subject on its two faces to brake pipe and auxiliary reservoir pressure respectively is provided and is adapted under the action of the increasing brake pipe pressure if the electric release action fails, to open a valve 19<SP>1</SP> by projections 90<SP>1</SP> thus connecting the chamber 53 to atmosphere by passages 132, 123, 112, 113. If with the valve in the release position shown, the brake pipe pressure exceeds that in the chamber 53 sufficiently to overcome the spring stop 102, the piston 12 is moved to the extreme right in which the feed groove 38 is cut off. Fig. 2 (Cancelled) shows the application of the invention to another type of triple valve, the regulating valve cover being replaced by a part 61 which comprises the magnet valves and the relay valve 18, use being made of the usual release relay valve.. The pipe 30 is connected to the brake pipe so that when the valve 41 is opened by energizing winding 3<SP>1</SP>, the chamber at the back of valve 18 is exhausted through port 136<SP>1</SP> and the valve is unseated by the brake