Pneumatic impact mechanism

Abstract

A pneumatic impact mechanism for driving rod-like members having a hollow cylindrical casing with a tail portion and a front end portion. The casing accommodates a reciprocating stepped hammer piston defining in the casing, on the tail portion side, a variable volume rear end work chamber in permanent communication with a source of compressed air. The stepped hammer piston defines, on the side of the front end portion, a variable volume front end work chamber. The stepped hammer piston has a through-passing axial bore, and its small-diameter portion cooperates with the tail portion of the casing and has radial passages. There is provided a tubular guide member or element for receiving the rod-like member arranged coaxially with the stepped hammer piston and casing and secured to the tail portion and to the front end portion of the casing in such a manner as to cooperate with the stepped hammer piston and define therewith, with the outer periphery thereof an axial passage. A clamp for engaging the individual rod-like members is rigidly removably secured to the front end portion of the casing. The front end-work chamber communicates, at regular intervals, with atmosphere through the axial passage and radial bores when the stepped hammer piston is in its rear end position and with the rear end work chamber when the stepped hammer piston is in the front end position to deliver blows to the casing under the action of compressed air fed to the work chambers.