GB256178A - Improvements relating to fluid pressure braking apparatus - Google Patents

Abstract

256,178. Westinghouse Brake & Saxby Signal Co., Ltd., (Assignees of Parke, F. H.). July 31, 1025, [Convention date]. Fluid-pressure. - Fluid-pressure braking apparatus comprises two braking equipments which may be applied either by straight air supply to the straight-air train pipe by means of a driver's valve and a controlling valve device associated with one of the brake equipments or automatically by a reduction in pressure in the automatic train pipe, such reduction being arranged to cut off communication between the straight-air train pipe and the controlling valve device of the equipment. The pipe supplying the brake cylinder 3 on the main locomotive is connected by the straight-air pipe 36 comprising a flexible hose connection 38 to a cut-off valve 16 on the auxiliary locomotive and through a cavity 39 in this valve and pipe 40 to the seat of the equalizing slide valve 11 in the distributing valve 5 and through passage 41 to the application cylinder 13. To effect a straight air application, the driver's valve 1 is operated to supply fluid under pressure to the application cylinder of the distributing valve 2 which supplies fluid under pressure from main reservoir 4 to the brake cylinder 3 on the main locomotive and to the application cylinder 13 of the distributing valve device 5 on the auxiliary locomotive. The movement of the piston 12 in the cylinder 13 supplies fluid from a reservoir 9 to the brake cylinder 10. A branch 34 of the automatic train pipe 32 normally supplies fluid to the piston chamber 14 of the cut.off valve 16, fluid also flowing through a feed groove 35 to. the valve chamber 17 and reservoir 7. The pressure on both sides of the piston 15 is thus equalized and it is maintained in normal position by a spring 44. On automatic application of the brakes, the drop in pressure in the automatic train-pipe 32 allows the higher pressure in the reservoir 7 to shift the piston 15 and thus cut off the straight-air pipe 36 from the distributing valve 5. The reservoir 9 is charged from themain reservoir 4 through pipes 29, 30 and a charging valve 8. Fluid flowing through a pipe 31 raises a diaphragm 18 in the valve 8 when the pressure has attained a certain value, thus raising a pin valve 21 and entering a chamber 22 to shift a piston 23 and a valve 25 connected thereto, allowing fluid to pass through pipe 30 to the reservoir 9. If the pressure in the pipe 30 is reduced by a burst connecting hose for instance, the consequent reduction in pressure causes the diaphragm 18 to be moved to close the pin valve 21 and the fluid in the chamber 22 escapes through a port 42 in the piston 23 and the valve 25 is closed to prevent escape of fluid from the reservoir 9. The port 42 is of such small cross-sectional area that, while charging, fluid enters chamber 22 more quickly than it can escape through the ports. Restrictions 37, 43 are provided in pipes 36, 30 to prevent leakage in case of a break-in-two.