DRILLING TOOL FOR ROTARY HOLE DRILLING Russian patent published in 1996 - IPC

FIELD: mining industry. SUBSTANCE: drilling tool has casing and blades fixed on casing for limited rotation about their axes of rotation and engagement one with the other in extreme positions. Main and auxiliary cutting members formed as sharpened hard-alloy plates are mounted on blades. Auxiliary cutting members are positioned at side opposed to side where main cutting members are mounted. Blades have plates defining profile mounted on blade generatrix and on main cutting members. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. 4 dwg