Patent ID: 8113303

Claim:
A cutter for a fixed cutter drill bit for cutting earth formations, the cutter comprising: a substrate for mounting on said bit, said substrate having a periphery, an end surface, a longitudinal axis extending through said end surface; and an ultra hard material disposed on the end surface, said ultra hard material layer comprising an exposed upper surface opposite said end surface and a peripheral surface, wherein said ultra hard material upper surface intersects said ultra hard material peripheral surface along a peripheral edge wherein said peripheral edge continuously decreases and increases in height as measured from a first plane perpendicular to said longitudinal axis, wherein a second plane along said longitudinal axis intersects said peripheral edge at a first point and a second point and wherein a third plane along said longitudinal axis and perpendicular to said second plane intersects said peripheral edge at a third point and a fourth point, wherein said peripheral edge has a first convex portion extending from said first point in a direction toward said third point and a first concave portion from said first convex portion to said third point, wherein said peripheral edge has a second concave portion extending from said third point in a direction toward said second point and a second convex portion extending from said second concave portion to said second point, wherein said peripheral edge has a third convex portion extending from said second point in a direction toward said fourth point and a third concave portion extending from said third convex portion to said fourth point, and wherein said peripheral edge has a fourth concave portion extending from said fourth point in a direction toward said first point and a fourth convex portion extending from said fourth concave portion to said first point, wherein the first concave portion and the second concave portion define a first continuous concave curve, wherein the second convex portion and the third convex portion define a first continuous convex curve, wherein the third concave portion and the fourth concave portion define a second continuous concave curve and wherein the fourth convex portion and the first convex portion define a second continuous convex curve.