Patent GB-190625578-A (GB)
Title: Improvements in Fluid-pressure Brakes.
Inventor: TURNER WALTER VICTOR
Filed: 1906-11-13
Granted: 1907-05-09
Abstract: 25,578. Turner, W. V. Nov. 15, 1905, [date applied for under Patents Act, 1901]. B r a k e s.-Relates to compressed-air brakes, for locomotives and trains, of the t y p e described in Specification No. 13,561, A.D. 1905, in which the driver can control the locomotive and tender brakes either in conjunction with the train brakes or separately. The distributing-valve is simplified ; brake-cylinder pressure i s limited i n service applications, and gradually reduced from a higher pressure in emergency applications by a blow-down valve, which is connected to the application or regulation chamber of the distributing-valve in its application positions ; a hand-operated valve for actuating the locomotive distributing-valves by straight air is interposed between the driver's valve of the automatic system and the locomotive distributing-valves, whereby the locomotive brakes can be operated independently of the train brakes; and, when two or more locomotives are drawing a train, the brakes on the second and following locomotives can be operated automatically with the train brakes by the driver of the head locomotive, or independently by their own drivers. The locomotive equipment is shown in Fig. 1. The triplevalve portion 1 of the distributing-valve mechanism is connected to the train-pipe 2 ; its piston 5 always shuts the train-pipe off from the valve chamber 3 which is in communication with the auxiliary pressure chamber 4. The regulation or application chamber 13 communicates with the piston chamber 15 of the valve for controlling the connexions between the brake cylinders 24, the pipe 19 leading directly to the main reservoir 20 and the exhaust 25. The driver's valve 37 of the automatic system is shown in Fig. 5. It is preferably formed of a number of sections secured to a fixed base section 74. The seat of its rotary disk valve 59 is shown in Fig. 7, and the disk valve 59 itself in Fig. 8. Air at main-reservoir pressure passes through the pipe and passage 19 to the upper side of the disk valve 59 ; while air reduced to train-pipe pressure by a feed-valve 40 is led by a pipe 39 to a port 38 in the valve seat. This seat is also formed with an exhaust port 43, train-pipe ports 41, 42, ports 44, 47 leading to the usual equalizing-chamber 45 of the driver's valve,. a port 48 connected, either directly or through a driver's straight-air valve 51, to the application chamber 13, and a port 49 leading to the exhaust port 56 of the straight-air valve 51. The disk valve 59, Fig. 8, has through ports 60, 61, a long cavity 62, and cavities 63, 64. The seat of the driver's straight-air valve 51 comprises, in addition to the exhaust port 56, a port 55 connected to the main reservoir through a reducing-valve 57, a port 52 leading to the port 48 of the driver's main valve 37, and a port 53 connected to the application chamber 13. When the locomotive and train brakes are both being operated by the driver's main valve 37, the straight-air valve 51 is kept in position to connect its ports 52, 53 and blank its port 55. In the 'running' position, the driver's main valve 37 occupies the position shown in Fig. 10. The train-pipe is fed through the port 38, cavity 63, and ports 42, 41, the equalizing-reservoir 45 is charged through the cavity 64 and port 47, and the application chamber 13 is vented to the atmosphere through pipes 54, 50, port 48, cavity 62, and port 43. Train-pipe air moves the triplevalve piston 5 to the position shown in Fig. 1, and air from the main reservoir or other source feeds through the port 30 in the slide-valve seat, Fig. 3, till the pressure in chambers 3 and 4 has risen sufficiently to move the piston 5 back and cover the port 30. For a service application of the brakes, the driver's valve is moved to connect the port 44 through the cavity 62 to the exhaust port 43, and blank all its other ports. The pressure above the equalizing-piston 73, Fig. 5, is thus reduced, whereby the valve 75 is raised to vent the train pipe 2 in the usual way and apply the train brakes. The triple-valve piston 5 is also moved to the right and uncovers the port 12, allowing the air in chambers 3 and 4 to flow into the application chamber 13, and, through passage 14, to piston chamber 15, until the pressure in chamber 3 has fallen to that of the train-pipe, when the valve 7 is lapped. The piston 8 is thereby moved to shut the brake cylinders 24 off irom the exhaust 25 by means of the slide valve 10, and open the valve 11 to admit main-reservoir air to the brake cylinders. Brake-cylinder pressure acts upon the piston 8 through a port 27 in a collar on the piston stem, this device being adapted to prevent the pressure, when first admitted from the main reservoir, from increasing too rapidly against the piston. When the pressures on the two sides of the piston 8 have equalized, it is moved back by its spring stop 29 to close the valve 11 ; but, owing to some lost motiou between the piston and the slide valve 10, the exhaust port 25 is not uncovered. The brakes are thus held on with a pressure equal to that in the application chamber 13. If the brake pressure falls by leakage, the piston 8 is moved to open the valve 11 and make up the brake-cylinder pressure to that in the application chamber. In the `service ' application ' position of the triple valve, a cavity 34, Fig. 4, in its slide valve 7, connects the application chamber through ports 31, 32, Figs. 3 and 2, to a blow-down valve 33, which limits the applicationchamber pressure to that required in the brake cylinder. To release the train brakes, the driver's valve is turned to the release' position, Fig. 9, in which main-reservoir air at full pressure passes to the train-pipe through ports 60, 42. If it is required to release the locomotive brakes as well, the driver's valve is then returned to the ' running' position, Fig. 10, in which the application chamber 13 is vented, as described above, and the piston 8 and its slide valve 10 are returned to the ' release ' position, Fig. 1. But if it is desired to retain the locomotive brakes on after the train brakes have been released, the driver's valve is turned to the 'holding' position, Fig. 11, in which the trainpipe and equalizing-chamber 45 are fed as in the ' running ' position, but the port 48 of the equalizing - chamber 13 is blanked. By turning the driver's valve alternately to the running' and ' holding' positions, the locomotive brakes can be released gradually. For an 'emergency' application, the driver's valve is turned to the position, Fig. 14, in which the train-pipe is vented through the port 41 and the larger branch of the cavity 62. In this position, a cavity 65 may connect ports 48 and 47, to increase the capacity of the application chamber 13 by that of the equalizing-chamber 45. The triple-valve piston 5 is now moved to its extreme position, compressing its spring and uncovering the port 12 to allow the air in the chambers 3, 4 to expand into the application chambers 13, 15. In this position, the blow-down valve is connected to the application chamber only through a restricted port 35, Figs. 2 and 4, in the slide valve; since, moreover, main-reservoir pressure can feed into the chamber 3 through the port 30 and a restricted port 36, Fig. 4, the pressure in the application chamber, and consequently in the brake cylinders, falls slowly to the limit fixed by the valve 33. To apply the locomotive brakes independently of the train brakes, the driver's straightair valve 51 is turned to connect ports 55, 53, when air from the main - reservoir pipe 58 passes to chambers 13, 15 and moves the piston 8 to apply the brakes, as described above, the triple-valve piston 5 not being disturbed. The valve 51 is then turned to lap' position, and the locomotive brakes can be gradually released by turning it alternately to running ' and lap' positions, since in the former position the application chamber is vented through the pipe 54, ports 53, 52, pipe 50, port 48, cavity 62, Fig. 10, and .port 43. When both the train and locomotive brakes have been applied, and the driver's main valve 37 has been returned to ' lap' position, Fig. 12, in which the port 49 is connected to the exhaust, the locomotive brakes can be released without interfering with the train brakes by turning the driver's straight-air valve 51 to connect port 53 to port 56, to exhaust the application chamber 13 through pipes 54, 72 and port 49. The locomotive brakes can then be reapplied independently by the valve 51. When two or more locomotives are used on a train, a valve 71 on the second and following locomotives is turned from the position shown in Fig. 1 to cut off the driver's valve from the train-pipe 2 and connect up the two parts of the pipe 70, which leads to the atmosphere, or, as shown, to the port 49 of the driver's main valve. The brakes on these locomotives can then be applied with the train brakes from the leading locomotive in the usual way, and, when train-pipe pressure is increased to release the brakes, the cavity 16 in the valve 7 connects the ports 12, 17 and vents the application chamber 13 through pipe 70 and the port 49 of the driver's valve, which is left in ' lap' position, Fig. 12. If the driver of the second locomotive desires to operate his brakes independently, he turns his main valve 37 to ' running' position, Fig. 10, to close the pipe 70 and open the port 48, when he can apply or release his brakes by means of the straight-air valve 51.