Patent GB-190513561-A (GB)
Title: Improvements in Fluid Pressure Brakes for Locomotives and Railway and other Vehicles.
IPC: B60T15/04
Filed: 1905-07-01
Granted: 1906-04-12
Abstract: 13,561. Westinghouse Brake Co., [Westinghouse Air Brake Co.]. July 1. Brakes.-Pneumatic-pressure brakes for locomotives and trains are arranged so that the driver can control the locomotive and tender brakes either in conjunction with the train brakes or separately therefrom. The ordinary auxiliary reservoirs and triple valves on the locomotive and tender are dispensed with, and a special arrangement of distributing-valves is employed by means of which air is supplied to the engine and tender brakes from the main reservoir at a suitably reduced pressure. These distributing-valves are controlled by the train-pipe air when all the brakes are worked together and by straight air when the engine and tender brakes are used separately. A special driver's valve in addition to the ordinary driver's valve may be used, or the ordinary driver's valve may be modified to perform the additional functions. The distributing-valves employed on the locomotive may be adapted for use on cars. Figs. 13 and 14 show an arrangement of distributing- valve for supplying air from the main reservoir to the engine and tender brake cylinders, wbich is controlled, together with the triple valves of the train, by the pressure in the train-pipe or the equalizing-reservoir. Air from the train-pipe enters by a connexion 18 and acts on the piston 22 of a valve 20, which is similar to the ordinary graduating triple valve and is adapted to connect a brakecylinder port 28 and a regulating-chamber 31 with an exhaust port 30, and so shut off the exhaust port 30 and connect the chamber 31 with the chamber 19. The chambers 19, 31 are fitted with enlargements 25, 32 to make them proportional in volume to the ordinary auxiliary reservoir and brake cylinder respectively. The pressure in the chamber 31, which is thus regulated in the same way as that in the brake cylinders of the train, acts on a diaphragm 33, below which is a chamber 34 connected to the brake-cylinder port 28. On reduction of the train-pipe pressure to apply the brakes, the pressure above the diaphragm is caused to exceed that below, and to open a valve 36, which allows air to pass by a port 37 from above the operating- piston 42 of a valve 40, which is in consequence moved to open the port 28 to the main-reservoir supply 17, thus applying the brakes. As soon as the pressure in the brake cylinder becomes equal to that in the chamber 31, the valve 36 is closed by a spring 39, and the valve 40 by a spring 44, the main-reservoir air leaking past the piston 42. A stop 72 limits the movement of the piston 42. In order to provide for independent operation of the locomotive and tender brakes, the modification shown in Figs. 9 and 10 is employed. A similar arrangement of triple valve 20, regulating-valve 36, and main-reservoir pressure supply valve 40 to that shown in Figs. 13 and 14 is used, except that the graduating-port 69, Fig. 13, of the valve 20 is omitted, and an additional driver's valve 46, Fig. 9, is used, which is adapted to connect the chamber 23 to the train-pipe or equalizing-reservoir so that the valve works like that shown in Figs. 13 and 14, or to cut it off from the train-pipe and to connect it as required with the main reservoir or with the atmosphere for releasing or applying the locomotive brakes independently of the train brakes. When the valve 46 is being thus used for controlling the locomotive brakes, it is arranged to connect up the chamber 31 to an additional enlargement 53, and the chamber 23 to another enlargement (not shown) in order to compensate for the increased pressure being used, or these enlargements may be dispensed with and the chamber 32 fitted with a loaded escape valve for preventing the pressure in the chamber 31 from exceeding a safe limit. The valve 46 is shown to a larger scale in Fig. 4, and its seating in Fig. 3. The valve has a through port 63, and cavities 64, 65, 66, 68. Air from the main reservoir has access to the top of the valve by a passage 67, Fig. 10. The valve face has ports 51, 57, Fig. 3, communicating with the train-pipe or equalizing- reservoir, ports 50, 56 communicating with the chamber 23, Fig. 9, an exhaust port 60, a port 55 leading to the chamber 19, elongated ports 61, 62 communicating respectively with the chamber 31 and the enlarging-chamber 53, and a port 58 leading to the enlarging-chamber for the chamber 23. Fig. 5 shows the valve in the position for trainpipe control, the thick lines showing the ports in the valve. For straight-air control, the valve is turned to bring the pressure ports 63 or exhaust cavity 68 over the port 56 as required, the cavity 66 at the same time connecting the ports 50, 58, and the cavity 64 the ports 61, 62. The cavity 65 is for connecting the ports 55, 57 when changing from straight-air control to train-pipe control, thus reducing the pressure in the chamber 19 to that of the train-pipe and preventing a re-application of the locomotive brakes. In a modified arrangement shown in Fig. 16, a single driver's valve is used for both automatic control, and straight-air control of the locomotive brakes, and the various parts of the distributing-valve device are separated from one another. In this arrangement the valve 136 controls the supply of air from the main reservoir 84 to the brake cylinders 139, the valve 129 controls the escape of air from the back of the piston 132 of the valve 136, a piston 125 subject to the pressure of a regulating-chamber 122 operates the valve 129 and also a brake cylinder exhaust valve 127, and a valve 110 operated, similarly to a triple valve, by a piston 106 exposed to the pressure of the trainpipe, controls the passage of air from the main reservoir to an auxiliary chamber or reservoir 121, from the chamber 121 to the regulating-chamber 122, and in a certain position of a cock 116, from the regulating-chamber 122 to the atmosphere. In the position shown, the cock 116 connects the ports 111, 112 of the valve 110 both to a pipe 118 leading to a port 94 in the driver's valve seat, but it can be turned to connect the port 112 to atmosphere and to disconnect the port 111 from the pipe 118. In the latter position of the cock 116, the distributing-valve device is controllable solely by the pressure in the train-pipe 87. When the driver's valve is moved to release' position, the piston 106 moves the valve 110 until it uncovers a side port 113, which allows air to pass from the main reservoir 84 to the chamber 121 until the pressure in this chamber just exceeds that in the tram-pipe ; the piston 106 then moves back and causes the valve 110 to lap the port 113. On a reduction of pressure in the train-pipe, the piston, 106 is moved against a graduation stop 123, and the chamber 121 connected to the regulating-chamber 122, thus applying the locomotive brakes together with the train brakes. With the cock 116 in the position shown, however, the release of the train brakes does not affect the locomotive brakes owing to the blanking of the port 94 in the driver's valve seat when the valve is in full-release position as described below. The driver's-valve seat has a train-pipe port 88, cavity 89, exhaust port 90, feed-port 91, preliminary discharge port 92, and equalizing-port 93 arranged in a known manner, and also the port 94 already described. The valve ports are indicated by thick lines in Fig. 19, which shows the running position ; they consist of through ports 96, 100, 101, a large cavity 97 with ports 98, 99, 103, 104, and a cavity 102 with an extension 143. In this position of the valve, the extension 143 connects the port 94 and thereby the regulating-chamber 122, Fig. 16, to the atmosphere, and the feed-port 91 is supplied with air from the main reservoir through one of the ports 100. The position for service application is shown in Fig. 20, the lap position in Fig. 21, and and the train-brake release position in Fig. 18 with the port 94 blanked for the purpose of retaining the locomotive brakes. To release the locomotive brakes, the valve is returned to the running position shown in Fig. 19. For independent straight-air control of the locomotive brakes, the valve is moved to the position shown in Fig. 22, in which the through port 101 coincides with the port 94, and then to the lap position shown in Fig. 23. In each of these positions the feed-port 91 and the equalizing-port 93 are kept open by the ports 100, 103 as in the running position, Fig. 19, in which the port 143 causes the release of the locomotive brakes. In place of this modified driver's valve, a separate additional valve 145, Fig. 24, may be used for the straight-air control. The seating for this valve has an exhaust port 149 and a port 144 leading to the pipe 118, and the valve has a through port 147, Fig. 25, and a cavity 148, main-reservoir pressure from the pipe 85, Fig. 24, being admitted to the space above the valve. In adapting the distributing-valve device shown in Fig. 16, for use on cars, a large auxiliary reservoir 150, Fig. 26, is employed and is supplied through ports 152, 153, Fig. 27, and a non-return valve 151 from the trainpipe 87, the ports 152, 153 being cut off by the valve 110 when the pressure in the auxiliary reservoir 150 just exceeds that in the train-pipe. The cock 116, Fig. 16, is also dispensed with; otherwise the apparatus is the same.