HELICAL CUTTING INSERT WITH STEPPED CUTTING EDGES Russian patent published in 1999 - IPC

FIELD: milling cutters with cutting inserts for milling straight side walls. SUBSTANCE: insert has body including lower surface, upper surface and lateral surface arranged between upper and lower ones. Stepped cutting edge is formed by crossing upper surface and lateral surface and it is designed for engaging with blank at chipping it. Stepped cutting edge has at least two stepped portions, each portion is designed for forming segment of chip at cutting operation. Insert is provided with means for engaging with blank by chipping it and forming thinned part of chip between chip segments. Said means are in the form of transitional part of edge joining stepped portion of edge. Transitional part of edge is arranged with possibility of crossing stepped portion of edge by obtuse angle. EFFECT: lowered cutting efforts, reduced wear of insert, enhanced chip breaking. 20 cl, 12 dwg