| 摘要 |
821,391. Vacuum brake systems. VACUUM BRAKE CO. Ltd. Sept. 11, 1957 [Sept. 12, 1956], No. 28641/57. Class 103 (1). A vacuum brake system for rail and road vehicles includes a vacuum pipe 2 communicating with a vacuum brake 26, a vacuum reservoir 21, and a vacuum reservoir 14 via a guide release valve 1; when the pressure in pipe 2 is at or near atmospheric the brakes are applied and when reservoir 21 is allowed to create a mixed vacuum in pipe 2 the valve 1 automatically operates to connect reservoir 14 to pipe 2 to create a vacuum surge to rapidly release the brakes. A piston 6, Fig. 1, controlled by diaphragms 7, 8 clamped between quick-release valve casing portions 3, 4, 5, is sealed against an inner casing wall 9 by ring 10 and is movable up and down by pressure differentials in chambers B, C, D; on rising a projection 11 engages and raises a valve 12, 13 to connect chambers A and D. On brake application, pressure in pipe 2 and chamber D moves piston 6 down, its portion 17 forcing valve 13 against seat 15 and a valve 19 closes bores 18 in valve 12, 13, pressures in chambers B, D equalizing through bores 16. For brake release, the reservoir 21 is connected to pipe 2 by driver's valve 30 creating a mixed vacuum in pipe 2, defined as being of the order of 18-19 inches of mercury, chamber D and eventually, through bores 16, chamber B, causing piston 6 to move up to raise valve 12 to connect reservoir 14 to pipe 2, the vacuum surge created is propagated to the next vehicle F to automatically operate its quick-release valve 1a to connect its reservoir 14 through chamber A to pipe 2 and so on for the remaining vehicles to release the brakes simultaneously. The brake cylinder 26 with the auxiliary reservoir 27 is connected to the pipe 2 through throttle valve 28, the reservoir 27 can be vented by valve 29. The system is evacuated during running by a generator 22 through non-return valve 23 and air filter 24, the vacuum created in chamber D and B and atmospheric pressure in chamber C causes piston 6 to move down to its lower position, reservoir 14 being exhausted through ports 18 until closed by valve 19 which is held open by spring 20 until the operational vacuum has been created in reservoir 14. |
