Drill bit roller cutter - with circumferential chisel-shaped webs having cutting inserts

摘要

A roller cutter including a body contains >=1 substantially chisel-shaped circumferential web extending outwardly from the body, and several hardened wear-resistant inserts, one end of which is substantially chisel-shaped, positioned in the web and the body so that the cross-sectional shape of the web and the inserts have substantially the same included angle, the combination of the web and the inserts presenting a relatively continuous chisel-shaped surface to the formation whereby on rotation of the body the chisel-shaped surface cuts >=1 circular kerf in the formation. Cutter is capable of drilling large dia. holes in hard formations.