ONE-CONE DRILL BIT Russian patent published in 1995 - IPC

FIELD: rock cutting tools. SUBSTANCE: one-cone drill bit has body 1 with pin 3 inclined relative to its longitudinal symmetry axis. Mounted on pin 3 is spherical roller bit 5. Roller bit 5 has two spherical protrusions 7 with radius less than that of forming spherical surface of roller bit 5. Protrusions 7 are located on roller bit 5 diametrically opposite and their spherical surface is smoothly conjugated with spherical surface of roller bit 5. Formed in cross-section in plane of maximum radii of curvature surface of protrusions 7 is elliptic plane intersecting symmetry longitudinal axes of body 1 and pin 3 at angle. Drill bit allows drilling of well with larger diameter than that of drilled interval before without use of special reamers. EFFECT: extended process capabilities of drill bit. 3 dwg