GB731580A - Improvements in railway ballast tamping machines - Google Patents

Abstract

731,580. Railway ballast tamping machines. MATERIEL INDUSTRIEL SOC. ANON. Aug. 6, 1953 [Aug. 7, 1952], No. 21715/53. Class 104 (2). In a railway ballast tamping machine with. tamping tools carried by a frame suspended from a piston which is slidable in a cylinder having a fluid supply pipe leading to a space beneath the piston for raising the frame the descent speed of the frame is regulated by valve means including a single acting valve in the pipe and means for adjusting the throttling effect to reduce the descent speed. The frame 2 carrying the tamping tools 6 is suspended from a rod 10 attached to a piston 11 slidable in a cylinder 12 mounted on a machine frame 1. The frame 2 is raised by passing fluid through a pipe 13 to a cylinder space 12<SP>1</SP> below the piston 11. The speed of descent of the frame 2, which falls under its own weight or is accelerated by passing fluid to a cylinder space 12<SP>11</SP> above the piston 11, is reduced through the operation of a single-acting valve in the pipe 13. The piston 11 on descending compresses the fluid into the space 121 which fluid escapes through the pipe 13 to move a block 14 into contact with an abutment 16, as shown in Fig. 1. With the block 14 in this position fluid can only escape through a small hole 141 in the block 14 and thus the speed of descent of the frame 2 is retarded. The speed of descent can be altered by replacing the block 14 by another having a larger or smaller hole 14<SP>1</SP>. To raise. the frame 2 fluid is passed through the pipe 13 to the chamber 12<SP>1</SP> and in passing moves the block 14 to the left, Fig. 1, and then passes freely through a chamber 151 in the valve. In an alternative arrangement' shown in Fig. 2 the sliding block 14 is replaced by a ball 17 and the amount of fluid passing through the valve as the frame 2 descends is determined by a milled out portion 22<SP>1</SP> of a shaft 22, arranged in a bore 20 and rotatably adjusted by means of a hand wheel 21 held in the adjusted position by a spring pressed ball, Fig. 3 (not shown). The descent of the frame 2 is limited by nuts 43 engaging stops 50 or 51. The stops 50 or 51 are carried by slide blocks 42 and are moved into the operative position by a fluid-actuated piston 53 through rods 52 or by a lever, Fig. 6 (not shown), or any other suitable means. The tamping tools 6 are moved towards and away from each other by screws 9 and are vibrated by an eccentric 3 through links 4.