Patent GB-768386-A (GB)
Title: Improvements relating to automatic couplers for railway and like vehicles
IPC: B61G5/08
Filed: 1954-11-16
Abstract: 768,386. Train pipe couplings. MARSH, G. C., GRESHAM & CRAVEN, Ltd., WILSON, E. J., ENGLISH STEEL CORPORATION, Ltd., KERSHAW, J. W. G., and WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Nov. 3, 1955 [Nov. 16, 1954], No. 33121/54. Class 99(1) In an automatic coupler for railway vehicles including a vertical face 10 arranged to abut a corresponding face on a mating coupler and in which when the two couplers are locked together relative movement between the two faces is prevented, a detachable train pipe connecting unit for use with a vacuum braking system comprises a hollow body 23 defining a chamber open at one end 24 and closed at the other end and having a port for permanent communication between the chamber and train pipe, a valve 29 for closing the open end of the chamber, a resilient sealing member 28 around the open end of the chamber for engagement with a corresponding member on the mating coupler, and means for automatically opening the valve by coupling of the two couplers. The valve 29 is biased by a spring 32 towards the closed position thereof and is held open by the flow of air between the train pipe and the atmosphere through the chamber when the two couplers are accidentally parted and remains open until the difference in pressure between the pipe and atmosphere is reduced to a value no longer sufficient to hold the valve open against the action of the spring. As shown in Fig. 2. the body 23 has a port 26 communicating with a train pipe connecting piece 18 integral with the body and held, by a helical spring 27, in abutment with a bolt 17 retained in lugs 16 located on either side of a split in the housing 14 provided in the coupler for the connecting unit. A frusto-conical sealing member 28 of rubber is disposed on the face of the body at the open end 24 thereof. The valve 29, in the uncoupled condition of the coupler, extends beyond the front face of the body and is formed with a hollow stem 30 telescopically engaging a tubular extension 31 of a cap 25 closing the inner end of the body; the stem contains a helical spring 32 by which the valve is biased on to an inwardly-projecting seating of the body. When the units of mating couplers are engaged together, the valves coacting to open each other, the springs 27 press the sealing members 28 of the units together to form a fluid-tight seal. In a modification, a connector unit for a compressed air system has a body comprising end parts 52 and 53, Fig. 3, screwed into an intermediate cylindrical section 54 and includes an auxiliary valve 41 provided a stem 43 on which is slidably mounted a sleeve 42 carrying an annular, main valve 40 seating on an inwardly projecting shoulder at the open end of the body part 52 and having a conical seating surface 40a for the valve 41. The stem 43 is of reduced section in the region of ports 44 in the sleeve 42, and the valve 41 is normally maintained closed by a spring 46 extending between a shoulder on the sleeve and a collar 47 fixed to the stem 43. Within the section 54 of the body is a bush 55 formed with a guide 56 supporting the sleeve 42, and affording a sliding surface for a cup-shaped piston 48 fitted with a packing ring 49 and closing the rear end of the body of the unit; an axially extending blind hole 51 in the stem 50 of the piston accommodates the stem 43 of the valve 41. Located between an internal flange 58 of the body part 53 and a plate 59 retained in place by a ring 60 adjacent the rear end of that part is a spring 57 which, when the unit is installed in the housing provided in the coupler, acts to push the unit forward to hold the train pipe connecting piece 18 against the side of an L-shaped slot 61 in the housing. The plate 59 is positioned clear of the ring 60 by engagement with an abutment 62 formed in the coupler housing. When the coupler is uncoupled, the spring and plate are rendered captive by the ring within the body; also, the body part 52 projects beyond the vertical face 10 of the coupler and the stem 50 of the piston 48 is held separated from the plate 59 due to abutment of the piston, under the action of the spring 45, against a shoulder 63 of the body part 53. If the coupler is parted from its mating coupler, the compressed air in the chamber of the connector unit holds the valve 40 seated, forces open the auxiliary valve 41 and escapes to atmosphere thus reducing the air pressure in the train pipe and causing an application of the brakes; reduction of the pressure in the train pipe to a predetermined value allows the valve 41 to be closed by the spring 46. In a further modification, a unit for making a connection between the steam pipes of adjacent vehicles, includes a cap 25 similar to that shown in Fig. 2 but slidable in the body 23 and extended rearwardly to abut the rear wall of the housing for the unit, the spring 27 bearing directly against the body. Two units, one for an air pipe connection and the other for a steam pipe connection may be installed in the same coupler, there being corresponding units in the mating coupler.