866,111. Railway track packing machines. MATERIEL INDUSTRIEL S.A., and CONSTRUCTIONS MECANIQUES SOC. ANON. RENENS. June 25, 1958 [June 26, 1957], No. 20385/58. Class 104 (2). A self-propelled track packing machine arranged to travel along a rail track step at a time, equal to the sleeper spacing, and having at least one vertically movable carrier which carries packing tools for operation on the track when the carrier is lowered is provided with control equipment which determines the distance travelled in one step and is preadjustable to cause the machine, at each travel step, to advance a predetermined distance and then stop. In the embodiment shown in Fig. 1 tamping tools 4 are arranged on a member 2 vertically movable in a chassis 1 by means of a pressure cylinder 3. The machine is driven along the rails 6 by a motor 7 through a gear-box 10, chain 9 and wheels 8. The gear-box 10 is actuated by a lever 11 connected to a rod 12 in turn connected at its other end to a lever 13 carrying a brake shoe 14. A rod 15 connects the lever to a spring-biased piston 16 of a servomotor 17. The apparatus operates as follows. The machine is started by manually actuating a lever 19 connected to a mechanism which causes the piston 16 to move the gear lever 11 into the operative position and to disengage the brake shoe 14. At the same time the lever 19 moves a slow release relay 20, previously adjusted by lever 21, to the operative position. After a predetermined time the relay 20 operates to cause the piston 16 to be returned to the position shown in order to move the lever 11 to the inoperative position and to apply the brake shoe 14 to stop the machine in a position in which the tamping tools 4 are located in the correct position above the next sleeper on which a working operation is to be effected. In a further embodiment, shown in Fig. 2, the machine comprises two tamping members 2, 2a and the machine operates as follows. Commencing from the position shown in the Figure control distributers 24, 24a are actuated to connect conduits 23, 23a to atmosphere and to close conduit 26. The members 2, 2a are now lowered by their own weight. Cams 57, 57a, arranged respectively, on the members 2, 2a, depress plungers of distributers 29, 30. Conduits 36, 42 connected to conduit 28 leading from a compressed-air tank 27 are now closed. The conduit 37 communicates with atmosphere through the distributer 29 and the conduits 38, 39, 40 and 41 are connected to atmosphere through distributers 30 and 31 and a valve 34. Servomotors 17, 44 are also connected to atmosphere. In this position an arm 53, mounted on a pulley 52 rotated by a belt 51 driven by a pulley 50 engaging a track wheel 8a, rests against an adjustable stop 54. When control levers 25 and/or 25a are operated a distributer 24 and/or 24a places a conduit 26, connected to the compressed-air tank 27, into communication with conduits 23 and/or 23a. The air pressure in conduit 23 and/or 23a now causes a piston 22 and/or 22a to lift the members 2 and/or 2a. The cam 57 and/or 57a is now moved free of a plunger of the distributer 29 and/or 30. If only member 2 is lifted the distributer 29 places conduit 36 in communication with conduit 37 which, however, is cut off from conduit 38 so that the machine is not advanced along the rail track. The same applies if member 2a only is raised since conduit 38 communicates with atmosphere through conduit 37 and distributer 29. If the two members 2 and 2a are lifted the machine can advance along the track. The conduit 36 and 37 place conduits 38, 39, 40 and 41 under air pressure. The conduit 36 and 37 place conduits 38, 39, 40 and 41 under air pressure. The conduit 43 is closed by a ball 35 thus having two results. First a piston 46 is moved against the spring 45 to rotate the lever 48 about a pivot 49 in order to press the pulley 50 into engagement with the wheel 8a and secondly to move a piston 16 against a spring 18 to release the brake shoe 14 and to move the lever 11 of the gear-box 10 to the operative position and to cause the vehicle to move along the rail track. As the machine advances the wheel 8a rotates the pulley 50 to cause the arm 53 to rotate until it depresses a plunger of a distributer 31 to close conduit 39 and place conduits 40, 41 into communication with atmosphere thus causing the servomotor 17 to apply the brake 14 and to move the lever 11 to the inoperative position to stop the vehicle above the next sleeper on which an operation is to be effected. The angular movement of the arm 53 is proportional to the distance travelled by the machine and can be adjusted by moving the stop 54 in a circular arc by means of a lever 56 under the control of the machine operator. If the machine is to be moved, whether the members 2, 2a are in the raised or lowered position the plunger of the distributer 32 is depressed. The conduits 43, 41 are then placed under air pressure through the conduit 42 and the ball valve 35 closes the conduit 40 to place the servomotor 17 under pressure to move the brake shoe 14 and the lever 11 to the operative position as previously described. The forward movement of the machine will cease when the plunger of the pusher distributer 32 is released. The forward movement of the machine may be predetermined by suitably graduating the slides 55.