PERCUSSION-ROTARY MECHANISM Russian patent published in 1998 - IPC

FIELD: mining and construction industry. SUBSTANCE: this can be used in hand-held drills. Percussion-rotary mechanism has body with internal tapered surface. Located in body is stem brought in rotation by motor. Spindle of tool has shank located in round axial hole of stem. Striker is concentrically located on stem and has slot-type movable joint with tool spindle. Also provided are pivoted joints with levers. Stationary installed on some of levers are centrifugal weights and rollers which interact with internal curvilinear surfaces of disk-type cam which is rotated by roller in idle running. Disk-type cam is decelerated by means of pin when it is in contact with shank of tool spindle and with surface of slot in disk-type cam. Contact of external tapered surface of cam with mating tapered surface of mechanism body is achieved when tool comes in contact with material to be treated or rock mass to be drilled. This ensures transition to working mode of drilling or striking. Working mode of operation is adjusted by pressing on drill handle. Mechanism allows for increasing reliability of performance and reducing amount of metal needed for manufacture of percussion-rotary mechanism. EFFECT: higher efficiency. 2 dwg