Patent GB-190809682-A (GB)
Title: Improvements relating to Fluid Pressure Brakes for Railway and other Vehicles
Inventor: TURNER WALTER VICTOR
Filed: 1908-05-04
Granted: 1908-11-05
Abstract: 9682. Turner, W. V. May 6, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Brakes.-In a valve device for fluid - pressure brakes, which operates on a further reduction of trainpipe pressure after an application of the brakes in which the pressure in the brake cylinder and the auxiliary reservoir have equalized, to cause the valve to cut out communication between the auxiliary reservoir and the brake cylinder, and to connect the latter to a supplementary source of high pressure, means are provided for allowing graduated applications with high pressure ; the valve also provides, on the release of the brakes after an application with high pressure, for returning part of the air in the brake cylinder to the auxiliary reservoir. The triple-valve casing is connected at 1, Fig. 2, to the train-pipe, and contains the valve piston 15 controlling the main slide valve 12 and graduating- valve 13. The casing is connected by a pipe 7 to a chamber 9 or to atmosphere, and by a pipe 6 to a control pipe 8 or supplementary reservoir which supplies the air for increasing the brake-cylinder pressure. The communication between the valve chamber 11, connected with the auxiliary reservoir, and the brake cylinder pipe 5 is controlled by a valve 16 actuated by a piston 18, the two sides of which communicate by passages 25, 26 with ports in the valve seat. In the full release position, shown in Fig. 2, the piston 18 is moved to the right by a spring 20, the passages 25, 26 being both open to the valve chamber 11. The brake cylinder is open to the exhaust 31 through a cavity 21 in the valve 16, passage 24, ports 27, 29 in the main valve 12 connected by a cavity 28 in the graduating-valve 13, and exhaust cavity 30. The chamber 9 is also exhausted through a port 41 and the cavity 30. The control pipe 6 communicates with the valve chamber 11 through a check valve 33 in a passage 32 leading to a port in the valve seat, which registers with a port 45 in the valve. In a service application of the brakes, the graduating- valve moves to the left to close the brake-cylinder exhaust port 27, to cover the port 45, and to uncover a port 34, and the main valve is then moved until the piston 15 abuts against the spring stop 35. In this position the port 34 registers with the port 24 in the valve seat, and air passes from the auxiliary reservoir to the brake cylinder through the cavity 21 in the valve 16. When the pressures in the brake cylinder and the auxiliary reservoir have equalized, a further reduction in the train-pipe pressure causes the valve piston 15 to compress the spring of the stop 35, as shown in Fig. 4. The left-hand side of the piston 18 is then open to the exhaust cavity 30 so that the piston is moved to the left, uncovering the brake cylinder port 22. Air from the control pipe 6 passes through the passage 32, cross-over port 39, 37, 38 in the valve 12, and the passage 26 to increase the pressure in the brake cylinder. At the same time, the valve-chamber 11 vents into the chamber 9 through ports 42, 41, so that the pressure is reduced, allowing the train-pipe pressure to move the valve 12 to lap position. In an emergency application of the brakes, the valve is moved directly to the position shown in Fig. 4, and air is supplied to the brake cylinder from the control pipe 6, and also from the auxiliary reservoir through a passage 43 leading to the valve chamber 17. A gradual release of the brakes after an application at high pressure may be obtained by causing a wave of increased pressure to flow in the trainpipe, moving the valves 12, 13 to release position. Air then passes from the brake cylinder through the passage 26 to the chamber 11, and also from the control pipe through the port 45, Fig. 2, until the pressure in the chamber 11 is sufficient to move the valves to lap position. Further reductions in the brake-cylinder pressure may be similarly obtained until the pressures in the chamber 11 and the brake cylinder, and consequently the pressures on the two sides of the piston 18, have equalized, whereupon the spring 20 moves the piston 18 to the right. Further increases in train-pipe pressure cause the valves to be moved into the position shown in Fig. 2, the brake cylinder exhausting through the cavity 30 until the pressure admitted from the control pipe through the port 45 is sufficient to move the piston 15 and the graduating-valve 13 to lap position, closing the auxiliary exhaust port 27 and the inlet port 45.