Soft formation drill bit

摘要

A rock bit with rotary cone cutter means having hardened insert teeth utilizing fewer than the normal number of teeth or of cutters used for a given gage hole wherein the cone cutter body is of greater diameter and for approximately the same axial length, of a greater wall thickness and to accommodate a greater insert tooth depth or grip length and permit a proportional increase in extension of the insert from the cutter body to provide greater penetration with fewer insert teeth in contact at a given time, and also providing for increased journal bearing area to increase the life of the extended insert cutters.