A percussion tool, in particular for the production of the mines and subject of the work.

摘要

P & this percussion tool comprises a hammer 13, a working tool 15, a spring 21 or other energy accumulator and a loading mechanism of the hydraulic circuit used to compress the spring then releasing the hammer to the strike, and which comprises a housing 29 containing a compression chamber of large diameter and surmounted by a chamber of smaller diameter. The rod 25 of the hammer is extended by a rod 31 which slides in the housing 29 and which comprises a lower part of large diameter and an upper part of smaller diameter, separated by an annular stop biconical. A compression sleeve which slides in the compression chamber comes to bear on the annular abutment with a sealed joint in order to form therewith a two-part piston. In a first time, the piston 6 is pushed upwards by pulling the rod and compressing the spring 21. At the end of the ascending stroke, a sleeve of a step-by-step diameter which surrounds the rod to reveal an orifice of the casing in order to allow the pressure acting on the upper surface of the piston and thus release the hammer, the hydraulic fluid being expelled without resistance of the compression chamber. / p