BORING BLADE ROCK BIT Russian patent published in 2004 - IPC

FIELD: rock-destroying equipment. SUBSTANCE: rock bit has body and radial blades. Front edge and calibrating surface are reinforced with hard alloy along the full length. Rock bit is provided with plates, which are connected to the body and blades for forming the passage for washing fluid, lower parts of said plates being provided with safety half-openings. Plates are placed with possibility of overlapping the pit-face in one turn. Blades have grooves placed on the side of calibrating surface at different heights relative to each other. EFFECT: increased rock bit cutting due to self-sharpening blades, fluid overflow creation onto calibrating surface, increased rock bit reliability. 2 cl, 3 dwg