Patent ID: 6196341
Filing Date: 2001-03-06
Classification: E21B

Abstract:
A superabrasive cutting element for use in an earth boring drill bit, comprising:a generally cylindrically shaped substrate comprising:a generally planar top surface having a first circumferential dimension;an outer perimeter surface having a second circumferential dimension greater than the first circumferential dimension of the generally planar top surface;a shoulder located at a vertical distance from the generally a planar top surface and extending a distance inwardly from the outer perimeter surface;a circumferential wall extending downwardly from the generally planar top surface and extending generally parallel to the outer perimeter surface and terminating at the inwardly extending shoulder;at least two annular grooves positioned radially toward the circumferential wall, each of the grooves extending generally downward from the generally planar top surface to respectively different vertical depths, each of the respectively different vertical depths of the at least two annular grooves being less than the vertical distance of the shoulder; anda superabrasive table comprising reduced residual tensile stresses upon the superabrasive cutting element being cooled from an elevated manufacturing temperature, the superabrasive table comprising:a generally planar upper superabrasive layer disposed across the generally planar top surface of the generally cylindrically shaped substrate and generally extending radially no further than the outer perimeter surface of the generally cylindrically shaped substrate;an annular skirt portion of the generally planar upper superabrasive layer extending to the shoulder and being disposed around the circumferential wall of the generally cylindrically shaped substrate; anda corresponding ring portion of the generally planar upper superabrasive layer disposed in each of the at least two annular grooves of the generally planar top surface of the generally cylindrically shaped substrate.