HYBRID DRILL BIT WITH HIGH PILOT-TO-JOURNAL DIAMETER RATIO

摘要

The invention disclosed and taught herein are directed to an improved hybrid drill bit and associated elements having at least two frusto-conical cutter assemblies, each rotatable around separate axles on the bit, and at least two fixed blade cutters adjacent the frusto-conical cutter assemblies. The improved drill bit expands the pilot pin to journal diameter ratio within the body of the frusto-conical cutter assembly, but within the confines of the allowable space of the frusto-conical cutter assembly.