PERCUSSIVE DEVICE Russian patent published in 1994 - IPC

FIELD: mining industry. SUBSTANCE: percussive device body 1 and striker 4 with piston form accumulating hollow, cocking chamber 7 and overflow chamber 8. Striker 4 has shoulder 13 and recess 14. Piston of striker is made in form of toroidal split ring 22, cylindrical bushing 15 with grooves on its inner and outer surfaces for sealing members, cylindrical split ring 18 and closing bushing 20 with recess 21. Split ring 22 is installed in recess 14 and cylindrical bushing 15, split ring 18 and bushing 20 are arranged on striker 4 successively between shoulder 13 and recess 14. Contacting each other, the end faces of cylindrical bushing 15 and split ring 18 are of cone shape with angle at cone vertex of at least 160 deg. During operation, striker 4 with piston reciprocates. Design of piston of striker 4 allows transfer of grooves for sealing members of piston projection from the surface loaded with intensive dynamic loads of striker 4 to cylindrical bushing 15 which due to presence of gap between it and outer surface of striker 4 is protected from effect of high-intensity shock waves. During blow, cylindrical bushing 15 undergoes only inertial loads which are minor in magnitude, as total mass of cylindrical bushing 15 and split ring 18 and bushing 20 contacting with it are less than mass of striker 4 conjugated with them by 1000 times. EFFECT: higher operate reliability of device and its service life due to reduced concentration of stresses in striker. 2 dwg