DIAMOND DRILL BIT Russian patent published in 1994 - IPC

FIELD: borehole survey. SUBSTANCE: diamond drill bit has body, diamond-containing matrix divided into sectors with flushing grooves. Working faces have protrusions located over concentric circumferences which are displaced in adjacent sectors with respect to each other. Number of full protrusion in sector is equal to integer. In each following sector vertexes of protrusions are displaced with reference to vertexes of preceding ones by value equal to 1/2 of width of protrusion of preceding sector. Sections of increased wear resistance are made on outer and inner sides of each sector of drill bit. Width of these sections in radial direction is equal to 1/2 of width of protrusion. EFFECT: increased wear resistance. 5 cl, 5 dwg