PNEUMOSTRIKER Russian patent published in 2004 - IPC

FIELD: well-boring equipment. SUBSTANCE: device has cylinder, adapter, head with a chisel fixed to it, piston with central passage having a thick portion and striking part, a spring. In a thick portion of piston, in its central passage, sliding valve is placed in special bores. Spring is placed between adapter and piston end for pressing said end to stem of a chisel. Piston has a stem capable of entering the central aperture of adapter and having a recess. Three rows of bores are made in central passage of piston. Sliding valve is pipe-shaped and has a compact partitioning wall with side ports on both sides of the wall. Bead of sliding valve is pressed to end of piston stem by means of spring, which is placed between the sliding valve and inner shelf in place where diameter of piston central passage lessens. EFFECT: assured supplying of all spent energy carrier into the well during both working and reverse piston stroke without additional losses. 1 dwg