Patent ID: 6712562
Filing Date: 2004-03-30
Classification: B23C,Y10T

Abstract:
A milling insert comprising a body having upper and bottom surfaces interconnected by an edge surface structure, a transition between the upper surface and the edge surface structure forming a main cuffing edge structure comprised of a plurality of identical main cutting edges, the body further including a plurality of protruding portions, each protruding portion disposed at a corner toward which two of the main cutting edges converge, each protruding portion forming a secondary cutting edge disposed outside of an intersection of imaginary extensions of the two main cutting edges, the secondary cutting edge being joined to a first of the two main cutting edges by a transition edge; the edge surface structure forming a plurality of clearance surfaces for respective ones of the main cutting edges, each clearance surface including a first portion extending from a respective main cutting edge, a second portion disposed behind the first portion with reference to the cutting edge, and a third portion extending from the second portion in a direction toward the bottom surface, the second and third portions together forming a generally convex profile, wherein the first portions of the respective clearance surfaces extend convergingly toward the bottom surface, wherein the first and second portions of each clearance surface form respective first and second acute angles with a line extending perpendicular to a plane defined by the bottom surface, the first acute angle being smaller than the second acute angle.