US Patent 7690442 Drill bit and cutting inserts for hard/abrasive formations

A rolling cone drill bit comprises a plurality of bottomhole cutter elements positioned in a first circumferential row, wherein at least one of the cutter elements comprises a cutting portion extending from a base portion to a point furthermost from the base portion, defining an extension height. The ratio of the cross-sectional area of the cutter element at a point equal to ninety-four percent of the extension height to the cross-sectional area of the cutter element base is greater than 0.2. Moreover, the ratio of the extension height to the base diameter is not greater than 0.75.