DEVICE FOR ROTARY DRILLING Russian patent published in 1997 - IPC

FIELD: mining industry, in particular, tools for blasthole rotary drilling. SUBSTANCE: device includes tubular drill rod carrying Y-shaped drill bit which has shank, working head with wings armored with hard-alloy inserts provided with main and auxiliary cutting edges formed by internal faces of wings, central channel made in working head and communicating shank hollow with inlet, and inclined radial channels oriented from end face of working head. Formed between end of drill rod and base of shank hollow is chamber. Inclined radial channels are made in form of bores in shank wall connecting chamber, formed by end of drill rod and base of shank hollow, with annular space. Segment recesses are made on external surface of end of drill rod located in drill bit shank. Recess length exceeds length of part of drill bit found in shank. EFFECT: higher efficiency. 3 cl, 3 dwg