Patent ID: 6527486
Filing Date: 2003-03-04
Classification: B23B,Y10S,Y10T

Abstract:
Cutting insert for a rotary drill, comprising a body having a polygonal shape with substantially flat upper and lower surfaces, and edge surfaces adjoining the upper and lower surfaces; the lower surface having a smaller area than the upper surface to provide the insert with a positive cutting geometry; a first of the edge surfaces intersecting the upper surface to form a main cutting edge; the main cutting edge comprising short cutting edge portions converging from respective ends of the cutting edge and forming an obtuse angle with one another; at least one end of the first edge surface joining a second one of the edge surfaces by a curved nose portion; the curved nose portion intersecting the upper surface to form a curved cutting edge defined by a plurality of sequentially arranged curved cutting edge segments having respective radii, the radii being of different respective lengths, wherein a first of the segments is joined to an end of a respective main cutting edge, a second of the segments projecting farther laterally outwardly than the first segment to define a wiper segment, a radius of the second segment being longer than a radius of the first segment.