Pneumatic impact devices

A pneumatic impact device comprising a hollow cylindrical casing with side walls, an open end and a closed end;

• a nut closing the open end of said casing, said nut being provided with outlet channels and having an inner space;
• a multi-stepped ram located within said casing and adapted to reciprocate therein, an axial channel provided in said stepped ram and opening with one of the ends thereof on an end-surface of a maximum diameter step on said multi-stepped ram, a radial channel in said ram and communicating an outer surface of the maximum diameter step of said ram with said axial channel;
• a compressed air line for constantly communicating pressure to the inner space of said nut, a smaller diameter step on said multi-stepped ram, being disposed and extending within the inner space of said nut and subject to air pressure therein, said maximum diameter step of said ram comprising a front part of said ram and interacting with the inner surface of said casing, said maximum diameter step having at least one longitudinal channel and defining with the side walls and the closed end of the casing a working chamber for receiving compressed air from the compressed air line and the inner space of said nut through said channels of the ram, the pressure of said compressed air reacting on said smaller diametered step in said inner space of said nut to move the ram for delivering a blow and functioning to discharge the air thereafter, said longitudinal channel communicating constantly with the working chamber and periodically with the inner space of the nut and the compressed air line.