DRILLING BIT Russian patent published in 2003 - IPC

FIELD: drilling tools, particularly, drilling rock-cutting tools for well planetary-bit drilling. SUBSTANCE: drilling bit consists of welded or cast body with fastening thread, legs or sections with axles, radial thrust bearings and roller cutters whose external working surface is made in the form of combination of truncated conical surfaces located for formation of circular bottom hole with bit rotation round its axis. EFFECT: reduced expenditures for drilling bit manufacture and performance of drilling due to improved drilling bit design with reduced weight of roller cutters and simplified geometry of their working surfaces. 3 dwg