GB1041939A - Improvements in or relating to pneumatically operated reciprocating machines - Google Patents

Abstract

1,041,939. Percussive tools. A. CLANEL. March 11, 1965 [May 11, 1964], No. 10452/65. Heading B4C. A pneumatic rammer, comprises a piston 2 rigidly connected to a cylinder 1 and a movable piston 3 having a skirt 3a adapted to reciprocate over the latter piston and having a lower wall 5 formed with ports F co-operating with a rotary distributer 6 which selectively connects either a chamber G with a source of compressed air when the movable piston is in its lowermost position or an exhaust chamber H with atmosphere when the movable piston is in its uppermost position. The rotary distributer 6 is connected to one end of a rod 8, the other end of the rod having feelers 7 for engagement with a cam track 13 formed either in a sleeve 9 mounted in the stationary piston 2 or directly in the piston itself. In operation, with the rammer in the position shown, compressed air is fed through an inlet A into a chamber B to act on the piston 3, the chamber G being connected, via ports F in the wall 5 and aligned ports D in the distributer, with the exhaust chamber H and atmosphere. As the piston 3 moves downwardly the rod is rotated so that at the end of the stroke, slots C, Fig. 9 (not shown), formed in the periphery of the distributer are aligned with the ports F so as to permit the air in the chamber B to pass into the chamber G and so raise the piston 3, the exhaust passage then being blocked by the distributer. A wall N is formed at the top of the cylinder so as to define a cushion chamber at the top of the stroke and a spring washer 18 forms a buffer at the bottom of the cylinder. A valve 10 is provided for exhausting the chamber G if required.