Rock bit.

摘要

A rock bit having a body (1) integrally made with three legs (2), three bearing pins (3) implanted into the legs (2) and extending obliquely centripetally to the center line of the body (1), and three cone cutters (7) supported by the journals (6) thereof. The journal (6) of the bearing pin (3) has a shape of spherical segment with one base having a height larger than the radius, and a locking member (10) is provided to retain the cone cutter (7) in place. An appropriate conical shape of a though hole (5) in the leg (2) provided to insert the bearing pin (3) eliminates the need for block fabrication of the body (1).