Patent GB-862449-A (GB)
Title: Improvements relating to compressed fluid and vacuum braking apparatus
IPC: B60T13/46
Filed: 1958-10-29
Abstract: 862,449. Fluid-pressure brakes. WESTING- HOUSE AIR BRAKE CO. Oct. 29, 1958 [Oct. 30, 1957], No. 34684/58. Class 103 (1). A valve device 18 controlling admission and release of fluid to and from a brake cylinder 19 in a compressed fluid braking system, is controlled by the degree of vacuum in a train pipe 14 of a vacuum braking system and comprises an abutment 28 additional to a vacuum responsive abutment 26, arranged so that when subjected to fluid pressure supplied thereto by an independent application valve 3 it affects admission of fluid to the brake cylinder independently of the degree of vacuum in the vacuum train pipe. To charge the apparatus shown, the handle 7 of the independent application valve 3 and handle 12 of independent release valve 8 are turned to vent pipe 6 and chamber 34 of valve device 18 and to block pipe 9, the main reservoir 5 is charged from compressors on the locomotive and vacuum reservoir 16 exhausted via pipe 54; the driver's valve 1, actuated by handle 55, is moved to the release position to connect brake pipe 2 with passage 56, continually charged from reservoir 5 through a reducing valve 57; valve 23 is moved by handle 25 to charge pipe 24 from train pipe 2 to adjust valve 15 to establish a large capacity flow between vacuum reservoir 16, pipe 17, control valve 13 controlled by pressure in train pipe 2, and vacuum train pipe 14 and chamber 29 of valve device 18, the chamber 30 and volume 10 being exhausted through check valve 44. On completion of charging the apparatus is as shown, the handle 25 being returned to a normal position to vent pipe 22 causing valve 15 to close the large capacity flow to vacuum reservoir 16, the pipe 17 being now connected to reservoir 16 via choke 23a. Application of vacuum train and fluid-pressure locomotive brakes.-Handle 55 is moved to a service position to reduce pressure in brake pipe 2 and then moved to a lap position to maintain the required reduction; control valve 13, operated by this reduction, causes a proportional reduction of vacuum in train pipe 14 to brake the train vacuum brakes. The reduction in pipe 14 acts on chamber 29 to move abutments 26, 27 and valve 38 upwards against spring 48 to first close the atmospheric connection 53, 52, 50, 37 to the brake cylinder 19 on the locomotive and then open valve 41 to supply compressed fluid from reservoir 5 to brake cylinders 19. Brake cylinder pressure acts through passage 37 and choke 36 in chamber 35 to move valve 38 to a lap position when its reduced end just engages the closed valve 41. To release the brakes, handle 55 is moved to increase pressure in train pipe 2 which acts on valve 13 to increase the vacuum in train pipe 14, the valve device 18 returning to the shown position. For a quick release, handles 25 and 55 are moved to the release position to restore pressure in brake pipe 2 and pipe 22 to operate valve 15 for opening the large capacity flow between reservoir 16 and pipe 17 to rapidly increase vacuum in train pipe 14 and chamber 29. Release of locomotive brakes alone.-Handle 12 is rotated to vent pipe 9 and chamber 30 to move valve 38 down to vent brake cylinders 19. Atmospheric air will slowly vent chamber 29 and the vacuum train pipe 14 through choke 47 but the vacuum is maintained in pipe 14 from reservoir 16 via choke 23a and valve 13 to keep the vacuum train pipes applied. Independent application of locomotive fluidpressure brakes.-Handle 7 of valve 3 is moved to pressurize pipe 6 and chamber 34 from train pipe 4 to a pressure according to the degree of braking required, this pressure moves abutment 28 and valve 38 upwards to open valve 41 to apply the brakes.