PNEUMATIC REVERSIBLE PERCUSSION DEVICE FOR DRILLING HOLES IN GROUND Russian patent published in 1997 - IPC

FIELD: equipment for mining and construction industry. SUBSTANCE: device has body, striker, pipe union on larger diameter stage fixed in tail part of body and located in striker hole, rotatable stepped bush with opening, limiter of bush turning relative to pipe union provided with longitudinal circular recess in one of parts (pipe union or turnable bush) and protrusion rigidly fixed on other part of protrusion, lock in the form of circular flexible chamber, and nut with air supply hose. Lock is provided with cylindrical member which embraces flexible chamber and is held from turning relative to rotatable stepped bush and which is also provided with through radial spaces located at openings of lower step of pipe union. Flexible bush at deformation is bulging into these spaces. This embodiment enhances reliability of device due to additional fixing of turnable stepped bush in combine operation of flexible chamber and turnable bush. EFFECT: high efficiency. 8 cl, 9 dwg