Modular rotary cutting tools
Rotary cutting tools are disclosed comprising shanks and replaceable cutting inserts are provided. The shank comprises a pocket which receives an interchangeable cutting insert. The pocket includes a floor with a central pin-receiving hole, opposing pocket centering walls, and torque transmitting pocket drive walls. The cutting insert has a relatively long rear pin receivable in the central hole of the shank. A head of the cutting insert includes insert centering surfaces that contact the pocket centering walls of the shank, and insert drive surfaces that contact the torque transmitting pocket drive walls of the shank. The configurations and sizes of the shank and cutting insert features are controlled to provide improved torque transmission, rigidity and stability during operation of the rotary cutting tools.
1 . A modular rotary cutting tool comprising:
a shank having a central longitudinal axis and comprising a central pin-receiving hole and a front pocket, the front pocket comprising:
first and second opposing pocket centering walls wherein each of the first and second opposing pocket centering walls are disposed at a seating angle S of greater than 0.5° measured from the longitudinal axis of the shank;
first and second torque transmission pocket drive walls; and
a pocket floor; and
a cutting insert removably installable in the front pocket of the shank comprising a pin receivable in the pin-receiving hole of the shank,
wherein the first pocket centering wall defines a plane, the first pocket drive wall defines another plane, the first pocket centering wall plane and the first pocket drive wall plane intersect at a pocket intersection point P located at the pocket floor at a pocket wall angle A measured at the intersection point P, and the pocket wall angle A is from greater than 90° to less than 155°, wherein each of the first and second pocket drive walls are spaced apart from each other in planes parallel with the longitudinal axis of the shank such that a virtual extension of each of the first and second drive walls project unobstructed across a diameter of the front pocket.
2 . The modular rotary cutting tool of claim 1 , wherein the pocket wall angle A is from 130 to 150°.
3 . The modular rotary cutting tool of claim 1 , wherein the intersection point P is located at a pocket offset distance Y measured at the pocket floor in a direction in the first pocket centering wall plane from a plane in which the longitudinal axis of the shank is located, and the pocket offset distance Y is from 1 to 20% of a diameter D S of the shank.
4 . The modular rotary cutting tool of claim 3 , wherein the pocket offset distance Y is from 3 to 15% of the shank diameter D S .
5 . The modular rotary cutting tool of claim 1 , wherein the pocket has a pocket centering wall width W C measured at the pocket floor, a pocket drive wall width W D measured at the pocket floor, and the pocket drive wall width W D is greater than 10% of the pocket centering wall width W C .
6 . The modular rotary cutting tool of claim 5 , wherein the pocket drive wall width W D is from 25 to 75% of the centering wall width W C .
7 . The modular rotary cutting tool of claim 1 , wherein the seating angle S is from 1 to 4°.
8 . The modular rotary cutting tool of claim 1 , wherein the pin-receiving hole has a substantially constant inner diameter along an axial length of the pin-receiving hole.
9 . The modular rotary cutting tool of claim 1 , wherein the shank comprises coolant holes in front surfaces of the shank on opposite sides of the front pocket.
10 . The modular rotary cutting tool of claim 9 , wherein the coolant holes have the same size.
11 . The modular rotary cutting tool of claim 9 , wherein the coolant holes have different sizes.
12 . The modular rotary cutting tool of claim 11 , wherein the shank comprises an angled set screw hole extending through a side of the shank adjacent the first opposing pocket centering wall and adjacent a first one of the front surfaces of the shank to the central pin-receiving hole, and one of the coolant holes having a smaller size than the another one of the coolant holes is located in the first front surface of the shank that is adjacent the set screw hole.
13 . A shank of a modular rotary cutting tool, wherein the shank has a central longitudinal axis and comprises a central pin-receiving hole and a front pocket, comprising:
first and second opposing pocket centering walls;
first and second torque transmission pocket drive walls; and
a pocket floor,
wherein the first pocket centering wall defines a plane, the first pocket drive wall defines another plane, the first pocket centering wall plane and the first pocket drive wall plane intersect at a pocket intersection point P located at the pocket floor at a pocket wall angle A measured at the pocket intersection point P, and the pocket wall angle A is from greater than 90° to less than 155°, and wherein each of the first and second pocket drive walls are disposed in planes parallel with the longitudinal axis of the shank and wherein a virtual extension of each of the first and second pocket drive walls project unobstructed across a diameter of the front pocket.