Drill bit

Abstract

Abstract The drill-bit body (2) is fastened to the lower end of a set of rods engaged in the borehole (1). The boss (4) projecting into the spherical cavity (3) supports the shaft (6) carrying the rotary element (11) of spherical shape held in place by the nut (7). The outer surface of the element (11) is covered with hard particles, for example grains of hard metal or diamond elements. As a result of the drive of the drill-bit body (2) about its axis and the friction of the surface (18), the rotary element (11) necessarily rotates on the shaft (6), with the result that the entire inner face of the hole (1) is attacked by abrasion. <IMAGE>

Inventors

• 👤 René Treyvaud

Bibliographic Details