SHOT DRILLING BIT Russian patent published in 2011 - IPC E21B7/16 E21B10/02 

FIELD: mining.

SUBSTANCE: bit includes housing with screwed nipple and with spiral slots and protective sleeve arranged in cavity of the housing. Protective sleeve is installed in cavity of the housing with possibility of axial movement and provided with projection on outer surface; at that, bit housing is provided with support surface for interaction with projection of protective sleeve. As per the preferred version, projection of protective sleeve is made in the form of annular shoulder, and mating surface of housing is made in the form of annular bore.

EFFECT: higher operating reliability of drilling bit and thus higher technical and economic parametres of its operation.

2 cl, 1 dwg