US Patent 10100581 Rotary drill bit

A rotary dill bit with a drill bit head and a connecting portion, wherein the rotary bit is positioned and oriented for shearing a surface of a subterranean formation. The drill bit head is comprised of one or more cutting discs, wherein each cutting disc is rotatably mounted to at least one shaft between a pair of support structures with each cutting disc having a cutting disc edge extending outwardly beyond the support structures. The cutting discs have cutting inserts in an overlapping pattern, wherein each cutting insert comprises a projection extending from the cutting disc edge and angled from the cutting disc edge at a side rake and a front rake angle.