The present invention relates to diamond drag bits having cylindrical polycrystalline diamond faced inserts with a convex cutting surface, the insert being imbedded in the cutting face of a drag bit. The invention teaches an optimization of the geometry of the cutting face of cutting elements, particularly...http://www.google.com/patents/US5332051?utm_source=gb-gplus-sharePatent US5332051 - Optimized PDC cutting shape
