CUTTING TOOL AND CUTTING INSERT HAVING EXACTLY THREE CUTTING PORTIONS THEREFOR Russian patent published in 2018 - IPC B23B27/04 

FIELD: molding.

SUBSTANCE: cutting tool comprises indexable cutting insert (20) with three cutting portions (26). Cutting insert (20) is removably securable to insert holder (52) by means of fastener (54). Cutting insert (20) has two opposing end surfaces (22) with peripheral side surface (24) extending therebetween. At least one end surface has central boss (36) protruding therefrom with raised support surface (38), and the peripheral side surface has three abutment recesses (28). In an end view of the cutting insert, each of the three abutment recesses is visible and located inside a first imaginary circle (C1) circumscribing the visible central boss. Holding portion of the insert holder has seating surface (58) with at least one protuberance (60a, 60b) protruding therefrom. Said support surface is in clamping contact with the seating surface, and exactly two of the three abutment recesses are engaged with the at least one protuberance.

EFFECT: invention provides increased strength of fastening of the cutting insert, possibility of its installation on the left and right cutting tools and increased depth of the groove to be bred during boring.

18 cl, 9 dwg