ROCK CUTTING TOOL Russian patent published in 2006 - IPC E21B10/16 

FIELD: drilling equipment, particularly rock cutting tools provided with hard-alloy cutting structure having asymmetric working head or wedge- like cutting edge.

SUBSTANCE: rock cutting tool comprises body with blind orifices, rock-cutting teeth with working heads and stepped tails secured in body orifices by means of main and collet bushes. Collet bush is installed on tooth tail step having larger diameter. Main bush is installed on tail step having lesser diameter. Each collet bush is provided with at least one fixing unit, which prevents collet bush rotation relatively rock-cutting tooth and main bush press-fitted in body orifice so that main bush installation tightness exceeds that of low-diameter tooth tail stage installation in main bush. Collet bush fixer with rock-cutting tool includes flat spots created on side surface of large-diameter tooth tail step and brought into contact with inner bush surface. Collet bush fixer, which connects collet bush with main one, is made as clutch or pin coupling defined by aligned grooves and extensions on contact bush end surfaces.

EFFECT: increased reliability of teeth fixation in predetermined position.

3 cl, 7 dwg