GB976380A - Tamper - Google Patents

Abstract

976,380. Percussive tools. MASTER CONSOLIDATED Inc. Feb. 13, 1963 [March 19, 1962], No. 5853/63. Heading B4C. [Also in Division E1] A tamping tool comprises a shoe 6 providing a pedestal for a cylinder 1 on which a crank-case 13 is mounted for relative movement thereto by means of two relatively-slidable members 9, 10, a flexible bellows 12 between the housing and cylinder, and resilient means such as springs 18, 19, 20, 22, 23, 24 in the cylinder to induce an axial reciprocating jumping movement of the cylinder and shoe. The shoe is secured to the lower end of the cylinder via an end plate 2, the upper end of the cylinder being closed by an end plate 3. A hollow shaft 10 passes into the cylinder and has fixed thereto a piston-like member 15 which divides the cylinder into upper and lower chambers 26, 25 respectively, a set of the springs 22, 23, 24 being located in the upper chamber and a set 18, 19, 20 in the lower chamber. The upper end of the shaft 10 passes into a crank-case 13 and is secured to a yoke member 35, Fig. 3, which is reciprocated by means of a connecting rod 41 and crank 42, the latter being rotated via a gear 48 driven by an internal combustion engine 62. Before operation of the tool oil is fed via a hole 82 in the crankcase where it drains through holes in the bottom of the latter, interior of the bellows and holes 31 in the upper end of the cylinder and the cylinder then filling up to a plugged sight hole 30. In operation, upon movement downwardly of the shaft 10 the lower set of springs 18, 19, 20 are compressed so that upon the commencement of the upward travel of the shaft, the cylinder is caused to jump vertically; the subsequent compression of the upper set of springs causes a similar downward thrust on the cylinder. The relative movement of the cylinder and pistonlike member 15 is dampened by means of the oil in the cylinder being forced from one chamber to the other via the clearance space between the piston and cylinder. In order to lubricate the various parts in the crank-case, oil is forced upwardly through the hollow shaft 10 by means of a plunger 9 secured to end plate 2 and movable within a bore in the piston 15. The shape of the bottom of the shoe 6 is such that as the tamper jumps up and down it also moves forward.