CROWN BIT Russian patent published in 2006 - IPC E21B10/48 

FIELD: rock-destroying tools, namely, crown bits with diamond armaments for drilling wells and taking core samples.

SUBSTANCE: crown includes body and diamond-containing matrix, divided by washing grooves on sectors, reinforced by external and internal reaming and volumetric diamonds. Special feature of crown is the positioning schematic of reaming diamonds, which in vertical plane in each sector are mounted along inclined line, while beginning of line, positioned in frontal part of sector is shifted along height relatively to another end of line towards connecting thread.

EFFECT: significantly increased efficiency of operation of crown as a whole.

2 cl, 3 dwg