Cutting Insert Having Curved Ramps for Insertion Into a Tool Holder, Cutting Tool and Method of Assembly

A method for assembling a longitudinally elongated cutting insert (22, 122) in a holder blade (24), the holder blade (24), having a holder longitudinal axis (B) extending in a forward to rearward direction (DF, DR), comprising;

• a body portion (58) and a clamping portion (60);
• the clamping portion (60) having an insert receiving slot (62) opening out to a holder front end surface (64) of the holder blade (24), the insert receiving slot (62) comprising:
• an upper clamping jaw (66) and a lower base jaw (68);
• the upper clamping jaw (66) being resiliently displaceable relative to the lower base jaw (68),
• the lower base jaw (68) having a base jaw lower surface (72), the base jaw lower surface (72) including a front base jaw component surface (74) longitudinally spaced apart from a rear base jaw component surface (76), with a base jaw central surface (80) located between and recessed with respect to the front and rear base jaw component surfaces (74, 76);
• the cutting insert (22, 122) comprising:
• opposing insert upper and lower surfaces (26, 28) extending substantially parallel to an insert longitudinal axis (A) and a peripheral surface (30) extending therebetween;
• the insert lower surface (28) having two longitudinally spaced apart insert lower component surfaces (38), with an insert central lower surface (42) located between and recessed with respect to the two insert lower component surfaces (38);
• and
• the peripheral surface (30) having two opposing end surfaces (32) defining a longitudinal insert length (L), at least one of the end surfaces (32) having an integral cutting portion (34),
• the method comprising the steps of:
• positioning the cutting insert (22, 122) relative to the holder blade (24) so that the insert longitudinal axis (A) and the holder longitudinal axis (B) are contained in a mutual main plane (P2) and the insert lower surface (28) is in contact the base jaw lower surface (72);
• sliding the cutting insert (22, 122) rearwardly until the upper clamping jaw (66) undergoes resilient displacement;
• and
• applying an urging force (F) to the cutting insert (22, 122) in the rearward direction (DR) until the insert lower abutment surface (40) of the insert lower component surface (38) closest to the operative cutting portion (34) abuts the holder lower abutment surface (78) of the front base jaw component surface (74) and the insert lower abutment surface (40) of the insert lower component surface (38) furthest from the operative cutting portion (34) abuts the holder lower abutment surface (78) of the rear base jaw component surface (76).

A cutting insert (22, 122), longitudinally elongated in a direction defining an insert longitudinal axis (A), comprising:

• opposing insert upper and lower surfaces (26, 28) and a peripheral surface (30) extending therebetween, the peripheral surface (30) comprising two opposing end surfaces (32), at least one of the end surfaces (32) having an integral cutting portion (34);
• wherein
• the insert upper surface (26) comprises an insert upper abutment surface (36);
• the insert lower surface (28) comprises:
• two longitudinally spaced apart insert lower component surfaces (38), each insert lower component surface (38) having an insert lower abutment surface (40), the two spaced apart insert lower abutment surfaces (40) forming a lower imaginary line (LIL) parallel to the insert longitudinal axis (A), in a side view of the cutting insert;
• a cutout (29) formed in the insert lower surface (28) between the two spaced apart insert lower abutment surfaces (40) and bounded on one side by the lower imaginary line (LIL), the cutout extending for at least about one-third the length of the insert lower surface (28);
• an insert inner curved ramp (46) extending from at least a first of the two insert lower component surfaces (38) in a direction of the cutout (29);
• and
• an insert outer curved ramp (48) extending from at least a second of the two insert lower component surfaces (38) in a direction of an adjacent end surface (32).