HYDRAULIC PERCUSSIVE DEVICE Russian patent published in 2001 - IPC

FIELD: percussive mechanisms used in percussive machines in mining and other industries, in road building equipment. SUBSTANCE: hydraulic percussive device has body, tool, movable striker, working and back stroke chambers, control unit made in the form of differential three-stage control valve with sleeve located coaxially to movable striker in chamber communicating alternately with pressure and return main lines. Control unit has three chambers with active areas: extreme right-hand chamber with small active area continuously communicated with pressure main line, extreme left-hand chamber with large active area continuously communicated with return main line, and middle chamber continuously communicated with chamber of movable striker working stroke and periodically communicated with extreme right-hand or extreme left-hand chambers. EFFECT: higher operating reliability. 1 dwg