DRILL CROWN WITH FRICTION ELEMENTS Russian patent published in 2015 - IPC E21B7/14 E21B10/48 

FIELD: technological processes.

SUBSTANCE: invention relates to drill crowns for the destruction of strong mine rocks, including fractured and alternating ones as to hardness. The drill crown includes a housing with slots in the lower part, which are inclined to the side opposite to the crown rotation direction and divide the crown housing into stepped sectors, the advancing ones of which are reinforced with cutting elements and have the bending resistance providing the rise of cutters when the cutting resistance increases to an unallowable value for these cutters, and a guide sleeve arranged in the housing cavity. The lagging sectors are reinforced with heat-and-wear resistant friction elements. The guide sleeve is connected to the crown housing provided with a connection thread.

EFFECT: effective destruction of a working face and high mechanical drilling speed.

4 cl, 1 dwg