ROTARY-PERCUSSION BORE BIT Russian patent published in 2006 - IPC E21B10/36 

FIELD: rock drilling, particularly rotary-percussion bore bits adapted for fissured rock drilling.

SUBSTANCE: bore bit comprises body with cleaning channels, coupling shank and working head with diametrical groove for hard-alloy insert receiving. The bore bit is provided with at least one removable hard-alloy insert installation depth limiter connected to bore bit body. The insert installation depth limiter has end surface displaced with respect to hard-alloy insert end for controllable value. Each limiter is formed as a disc with axial channel. The disc is connected to bore bit by axle. Disc is eccentrically connected to the axle. Angle between axis of disc rotation and longitudinal bit body axis is 80-100°.

EFFECT: increased efficiency of fissured rock drilling.

6 cl, 7 dwg