Patent GB-865155-A (GB)
Title: Improvements in and relating to ballast-tamping or track-packing machines
IPC: E01B27/16
Filed: 1958-06-24
Abstract: 865,155. Railway track packing machines. MATERIAL INDUSTRIEL S.A., and CONSTRUCTIONS MECANIQUES S.A. RENENS. June 24, 1958 [June 26, 1957], No. 20199/58. Class 104 (2). In a railway track packing machine control equipment the number of operating strokes performed by the tool-carrier in each rest position of the vehicle is determined in accordance with the setting of a pre-selecting control-member and the next step of travel of the vehicle, after the pre-selected number of strokes, is initiated by means responsive to the movement of the tool carrier. In the arrangement shown in Fig. 1, a track packing machine, which comprises a chassis 1 on which is vertically slidable pairs of packing tools 3 mounted on a tool carrier moved by means of a piston 5 attached to a piston-rod 4 and working in the cylinder 6, operates as follows. In the position shown the vehicle is stationary, the tools 3 carry out a tamping operation on an underlying sleeper and the toolcarrier 2 is in its lowermost position under its own weight. A manually-operated valve 11 will have been operated to place a chamber 13 in communication with atmosphere through a conduit 12. Likewise, a chamber 15, of a cylinder 16, in communication with atmosphere through a conduit 14 and thus a piston 38 and pawl 36 are retracted by means of a spring 39. It is also assumed that a pre-selecting lever 26 has been engaged in a groove 29 of a guide-plate 30 so that a roller 32 mounted thereon engages one of the depressions 34 in the disc 33 and that the lever 26, under its own weight and through the agency of the cam 25, has depressed a plunger 21a to place conduits 18, 19 in communication. A cam 24 on the lower tool carrier 2 also holds a plunger 21 in the pushed-in position to cut-off conduit 18 from a vessel 9 containing compressed air. In this position a control device 23 holds the vehicle brake applied and the vehicle motor out of gear, thus immobilizing the vehicle. When the valve 11 is operated compressed air is admitted to the chamber 13, to raise the tool carrier 2, and to the chamber 15, to advance the piston 38, thus causing the pawl 36 to rotate the ratchet-wheel 35 by one tooth so that a disc 33 is moved by one-twelfth of a revolution. The disc 33 now raises and maintains raised the roller 32 and the lever 26. The plunger 21a now rises to close the conduit 18 and place conduit 19 in communication with atmosphere. The piston 5 also raises the tool carrier to move the cam 24 clear of the plunger 21 which places conduit 18 under air pressure from vessel 9. Since the tool carrier 2, due to its own weight, is raised relatively slowly the plunger 21a operates first and the conduit 19 remains at atmospheric pressure keeping the vehicle stationary. When the tool carrier 2 is lowered by a further operation of the valve 11 the chambers 13, 15 are discharged, the piston 38 retracts the pawl 36 while the disc 33 remains stationary and movement of the vehicle is prevented. When the tool-carrier 2 is raised for the second time, the disc 33 is again rotated by one-twelfth of a revolution and the roller 32 enters the next depression 34 so that the lever 26 depresses the plunger 21a. The plunger 21 is moved to place the conduits 17, 18 in communication and therefore places the control device 23 under pressure to put the driving-motor into gear and release the brakes of the vehicle to advance the machine a predetermined extent along the track, generally equal to a sleeper pitch, as regulated by the control device 23 which automatically disengages the driving- motor and applies the brakes. When the tool carrier 2 is lowered for a second time plunger 21 is pushed in by the cam 24 to exhaust the conduits 18, 19 and control device 23, thus immobilizing the vehicle so that the cycle can be started again. If the lever 26 is removed from the groove 29 and placed on a rest 41 the roller 32 is removed from the disc 33 and the lever holds the plunger 21a in the depressed position so that the conduits 18, 19 are in permanent communication and travel of the vehicle occurs every time the tool carrier 2 is raised. Several discs 33 may be keyed fast with the ratchet-wheel 35 to provide more than two types of cycle. A second pre-selection device for controlling the depth of tamping is shown in Fig. 2 and operates as follows:- When the tool carrier 2 is raised; air under pressure enters a chamber 15a, through a conduit 14a, to cause a disc 33a to be rotated onetwelfth of a revolution. A lever 26a is lifted and the plunger 42 rises to close a conduit 46 and to place conduits 12, 44 into communication, the latter conduit being temporarily closed at 45 by the piston 5. Pressure air also flows through a conduit 50, a ball valve 48 and conduits 47, 46 to the chamber 13 to lift the piston 5. When the tool-carrier 2 is subsequently lowered, the plunger 42 remains raised and air in the cylinder 6 exhausts through the conduit 44 until the piston 5 closes the orifice 45. The tool carrier is now immobilized in intermediate position affording a second tamping depth of tools 3. When the carrier 2 is raised a second time the rotation of the disc 33a places the plunger 42 in the position shown and pressure air in conduit 12 can flow either through the conduit 46 or through conduit 50, to chamber 13, to raise the piston 5. When the tool carrier 2 is lowered for the second time the plunger 42 remains in the position shown and air in the cylinder 6 escapes through conduit 46 until the piston 5 reaches its lowermost depth corresponding to the greatest tamping depth.