Cutting tool and round double sided cutting insert therefor

摘要

A cutting insert for retention in a rotating cutting tool having an axis of rotation has two opposing end surfaces and a peripheral surface extending therebetween, each end surface having a mutual first axis of symmetry passing through the end surfaces about which each end surface has N-fold rotational symmetry for some value of N where N is chosen from the group consisting of 2, 3 and 4. A peripheral cutting edge is formed at the junction between each end surface and the peripheral surface, the peripheral cutting edge having N curved cutting edges merging with N straight cutting edges which extend between the curved cutting edges at extremities thereof. The curved cutting edges of the two end surfaces are not aligned in an end view of the cutting insert along the first axis of symmetry.

主权项

1. A double-sided cutting insert (18, 118) for retention in a rotating cutting tool having an axis of rotation, the cutting insert comprising:
two opposing end surfaces (28, 128) and a peripheral surface (26) extending therebetween, each end surface having a mutual first axis of symmetry (B) passing through the end surfaces about which each end surface has N-fold rotational symmetry, where N is a number from the group consisting of 2, 3 and 4; a peripheral cutting edge (66, 166) formed at the junction between each end surface and the peripheral surface, the peripheral cutting edge comprising N curved cutting edges (32, 34; 132, 134) merging with N straight cutting edges (44, 50; 144, 150) which extend between the curved cutting edges at extremities thereof; wherein: the curved cutting edges of the two end surfaces are not aligned, as seen in an end view of the cutting insert: and each of the N curved cutting edges (32, 34; 132, 134) lies on a torus and extends along an angle equal to or larger than 120°, as seen along the first axis of symmetry (B).