Insert rotary cutter

An insert rotary cutter for processing a metal workpiece comprising:

• a cutter body having an axis of rotation therethrough;
• and at least one cutter insert releasably mounted on an outer periphery of said body, said insert being of a generally quadrilateral shape having four corners and a non-planar front face having an axis passing through the center of said front face, said front face having at least four marginal ridge with at least two of said ridges extending in opposed, parallel relation to one another and serving as respective main cutting edges, said front face having marginal portions disposed adjacent and extending along said main cutting edges, said marginal portions serving as respective rake surfaces of said main cutting edges, said cutting edges being disposed in spaced generally parallel relation, said main cutting edges being convexly arcuately curved and said other two of said four marginal ridges being concavely arcuately curved, each of said main cutting edges having a first end and a second end with said respective ends being spaced axially of said body, said insert having one end and an opposite end with said first end of one main cutting edges being at said one end and said first end of the other of said main cutting edges being at said opposite end of said insert, said front face, with respect to a first plane passing through said second ends of said main cutting edges and including said axis of said front face, being symmetrically concavely curved, said front face, with respect to a plane extending perpendicular to said first plane and including said axis of said front face, being symmetrically convexly curved.

A cutter insert for an insert rotary cutter having a generally quadrilateral shape having four corners and a nonplanar front face having an axis passing through the center of said front face, said front face having at least four marginal ridges with at least two of said ridges extending in opposed, parallel relation to one another and serving as respective main cutting edges, said front face having marginal portions disposed adjacent and extending along said main cutting edges, said marginal portions serving as respective rake surfaces of said main cutting edges, said cutting edges being disposed in spaced generally parallel relation, said main cutting edges being convexly arcuately curved and said other two of said four marginal ridges being concavely arcuately curved, each of said main cutting edges having a first end and a second end with said respective ends being spaced axially of said body, said insert having one end and an opposite end with said first end of one main cutting edges being at said one end and said first end of the other of said main cutting edges being at said opposite end of said insert, said front face, with respect to a first plane passing through said second ends of said main cutting edges and including said axis of said front face being symmetrically concavely curved, said front face, with respect to a plane extending perpendicular to said first plane and including said axis of said front face, being symmetrically convexly curved.