APPARATUS FOR MOUNTING BIT IN PERCUSSION ROTARY MACHINE Russian patent published in 1999 - IPC

FIELD: machine engineering, particularly electric manual perforators. SUBSTANCE: bit stem has two semicircular grooves with lengths restricted by upper and lower edges and it is mounted in guiding cylinder in such a way that to protect stem against release by means of locking member arranged in through slit of guiding cylinder and forced against release by means of spring-loaded sleeve. Additional locking member is arranged in additional through slit of guiding cylinder at level of lower edge of semicircular grooves of stem in position of percussion-free operation mode. Guiding cylinder is embraced by additional sleeve for radial motion of additional locking member. Additional sleeve is fixed in axial direction, it includes locking sector-shaped groove and lengthwise turning and may perform radial motion limited by angle formed by sector-shaped groove and lengthwise turning. There is mechanism for fixing terminal radial positions of additional sleeve covered by elastic casing. The last embraces bit stem and it is kinematically joined with additional sleeve. EFFECT: simplified design, enhanced manufacturing process, lowered mass and size of apparatus. 3 cl, 11 dwg