GB990517A - Transverse coupling between the bogie frames of a railway vehicle - Google Patents

Abstract

990,517. Railway vehicle undercarriages. SCHWEIZERISCHE LOKOMOTIV - UND MASCHINENFABRIK. July 12, 1961 [July 13, 1960], No. 25276/61. Heading B7L. A transverse coupling for the two bogies 1, 2, Figs. 1 and 2, of a railway vehicle and which reduces wheel flange pressures when the bogies negotiate a curved track, comprises a forked member 3 on the bogie 1 embracing the piston rods 6 on the ends of a working piston 5 in a cylinder 4 carried by the bogie 2, one or other end of the cylinder 4 being adapted to be supplied with fluid pressure in response to movements of a control piston 8 in a cylinder 7 carried by the bogie 2, which piston 8 is connected by a link 9, pivoted on the bogie 2, to the piston 5, the supply of fluid pressure to the cylinder 7 being controlled by a master piston and cylinder device 12 connected at A and B to the bogies 1, 2, whereby when the bogies are on a straight track as shown in Fig. 1, the coupling force is zero and when they are on a curved track as shown in Fig. 2, the coupling force tends to recentre the piston 5 and increases with a delay produced by throttle valves 31, 32 or by variable volume chambers 33, 34, Fig. 1. Compressed air is supplied to the cylinder 13 of the master control device 12 at 17, through either one of branches 17a and 17b. The piston 14 of the device 12 has enlarged portions normally shutting off the air supply to the space between the enlargements. This space is connected by a flexible pipe 18 to a space between enlarged portions of the portion 8 which normally block-off ducts 19, 20, between the cylinder 7 and the ends of the cylinder 4. The ducts 19, 20 are also connected by flexible pipes 23, 24, with cylinder 13 of the device 12 and are normally in communication with atmosphere through grooves 25, 26 in the piston 14 and ports 27, 28 in the cylinder 13. When the bogie 1 moves transversely relative to the bogie 2, but remains parallel thereto, there is no retraction or extension of the device 12 and thus both sides of the piston 5 are connected to atmosphere. However, when the bogies negotiate a curve they adopt e.g. the positions shown in Fig. 2 and the piston 14 moves into the cylinder and connects air pressure through the branch 17a, pipe 18, duct 20 (since piston 8 is moved by the piston 5) to the bottom end of the cylinder 4 whereby the piston 5 exerts a force on the fork 3 tending to re-align the bogies. At the same time air can escape from the top end of the cylinder 4 through the branch 19, the lower end of the cylinder 7 and to atmosphere through a duct 22 The upper end of the cylinder 7 has a similar atmospheric duct 21. The build-up of air pressure in the bottom of the cylinder 4 is delayed by the throttle valve 31 in the duct 20. Duct 19 has a similar throttle valve 32. The coupling may be operated by hydraulic pressure in which case the delay in the build-up of pressure in the appropriate end of the cylinder 4 is provided by either one of chambers 33, 34, connected to the cylinder ends and provided with pistons 35, 36, movable against springs.