Patent GB-190617771-A (GB)
Title: Improvements in and relating to Fluid Pressure Brake Systems.
Inventor: HICKS JAMES AMERS
Filed: 1906-08-07
Granted: 1907-07-25
Abstract: 17,771. Hicks, J. A. Aug. 7. Brakes.-In compressed-air brakes, the driver's valve is adapted to give independent control of the automatic brakes on the train and of the engine and tender brakes, the latter of which are actuated by straight air from the main reservoir, and are applied automatically if the train-pipe breaks. The invention is shown applied to a driver's valve of the Westinghouse type, which is connected to the main reservoir at MR, to the train-pipe at TP, and to the exhaust at E. The rotary valve 10, Figs. 1 and 8, works over a valve seat 5, and is shown in different positions thereon in Figs. 3 and 5, the ports and cavities in the rotary valve being distinguished by shaded edges. A valve casing 31 on the driver's valve is connected at 32, Fig. 9, to the engine and tender brake cylinders, and contains a valve 31 which controls ports 35, 36. The port 36 leads to a chamber 37, which is in permanent communication with the main reservoir through a groove 38, Figs. 3 and 5. The valve stem 39, Fig. 9, has a preferably loose connexion with a piston 43, which is subject on one side to train-pipe pressure through a passage 44, so that normally the port 35 is open and the port 36 closed, and the engine and tender brake cylinders are in communication through the passages 30, 29, 28, 27 with a groove 26 in the valve seat 5. In the " running " position, Fig. 3, of the driver's valve, the groove 26 is connected to the atmospheric port 46 by a cavity 45 in the rotary valve 10, so that the engine and tender brakes are off. A port 12 in the valve 10 registers with a port 16 in the valve seat, and main-reservoir air feeds down through the port 12, and through passages 17, reducing-valve 18, passage 19, and cavity 13 in the valve 10 to the train-pipe port 15<@a> and passage 20<a>. Air also passes through a port 20 to the equalizing-chamber 22, Fig. 1, containing the piston of the exhaust valve 23. To apply the engine'and tender brakes without applying the train brakes, the valve 10 is turned so that all the connexions are lapped except that a port 33 is situated over the groove 26, and main-reservoir air passes through port 33, groove 26, port 27, passages 28, 29, 30, and port 35 to the engine and tender cylinders. As the feed-port to the train-pipe is lapped, the train-pipe pressure may leak away, but, before it has fallen sufficiently to apply the train brakes, the engine brakes will have been fully applied and the driver will have to return his valve to " run- " ning " position to release the engine brakes. But by turning the valve to the intermediate position shown in Fig. 5, the engine brakes can be applied without interrupting the air feed to the train-pipe. In that position of the valve, the port 33 has caught the engine-cylinder groova 26, but the port 12 is still partly over the train-pipe feed-port 16 and the cavity 13 is in communication with the port 20 leading to the chamber 22. In the " service appli- " cation" position, the port 33 is still over the engine-cylinder groove 26, a groove 15<a> connects a port 12<a> leading to the equalizing-chamber 22 to a groove 12<b> leading to the exhaust, and the cavity 13 just connects the train-pipe port 15<b> with the exhaust port 24. In the " emer- " gency application " position, the port 33 is immediately over the engine-cylinder port 27, the train-pipe port 15<b> is in full communication with the exhaust port 24 through the cavity 13, and the equalizing-chamber port 12<a> is still connected to the exhaust. When the valve is turned to the " full " release " position for the train brakes, the engine brakes are still held on but are cut off from the main reservoir, the train-pipe is in direct communication with the main reservoir through port 15<b>, cavity 13, cavity 14<a>, and passage 14, and the port 12 is over the port 12<a> so that main-reservoir air can pass to the -equalizing -chamber 22. The engine brakes are released when the valve is returned to the " running " position. In all the abovedescribed operations, the valve 31, Fig. 9, has kept the port 35 open and the port 36 closed since, when the train-pipe pressure which acts against the piston 43 has been reduced, the valve 31 has been balanced by main-reservoir pressure on its two sides. But should the train-pipe break while the valve-controlled passage 30 is connected to atmosphere, the pressure in the chamber 37 would close the port 35, open the port 36, and allow main-reservoir air to pass to the engine cylinders. If, after such an application, the driver's valve is brought to "running " position to restore train-pipe pressure, the train brakes will be released before the engine brakes, because the valve 31 will not be