BORE BIT Russian patent published in 2009 - IPC E21B10/42 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to rock destroying tool, particularly to bore bits of cutting type, mainly for boring abrasive rock. The bore bit consists of a case with blades made with lengthwise slots and of inserts arranged in several layers in the slots; also inserts are armoured with rock destroying elements and are started up successively; further, inserts of lower layers are designed to perform axial displacement and are equipped with stops. The movable inserts are connected with the blades by means of a spring element preliminary hardened by aging in compressed condition; notably, inserts are thickened in their lower part, cross dimensions of which exceed width of blades slot and serve as stops for them; the stops are designed to interact with lower ends of the blades. Further, the blades with movable inserts are made out of material, wear resistance of which is less, than wear resistance of inserts material; their lower part is made with through cross clots.

EFFECT: simplification of design and reduced cost of bore bit.

3 cl, 2 dwg