PNEUMATIC PERCUSSION DRILLING MACHINE Russian patent published in 1996 - IPC

FIELD: mining, mechanical engineering, and other industries. SUBSTANCE: machine has body with exhaust ports, piston-striker located inside body and dividing inner body space into working and idle stroke chambers, air distributing mechanism, stationary stepped rod with its large step facing the idle stroke chamber. Striker is provided with central stepped hole and slots in its outer surface. Smaller step of striker central hole forms main pressure chamber with larger step of rod. Body inner surface has recesses forming channels with striker slots for communication between working and idle stroke chambers. EFFECT: high efficiency. 4 cl, 4 dwg