Patent ID: 7544021
Filing Date: 2009-06-09
Classification: B23C,Y10T

Abstract:
1. A rotary cutting tool with a longitudinal axis, comprising: a shank portion; a cutting portion extending between the shank portion and a free end, the cutting portion having a length, and at least three blades, wherein the blades extend substantially all of the length of the cutting portion, and wherein each of the blades includes a leading face side, a trailing face side, and a land surface extending between the leading face side and the trailing face side; and a plurality of chip-breaking features disposed in the land surface of each blade in a pattern that extends along the length of the cutting portion, which chip-breaking features disrupt an otherwise continuous land surface, and the pattern of chip-breaking features in each blade is different from the pattern of chip-breaking features in adjacent blades thereby creating a non-uniform distribution of chip-breaking features among the blades; wherein the plurality of chip-breaking features includes a first group of features, a second group of features, and a third group of features, which groups are axially spaced and, disposed in a particular one of the plurality of blades; wherein each group contains at least one feature; and wherein a first distance extending between a first feature of the first group and a first feature of the second group is unequal to a second distance extending between the first feature of the second group and a first feature of the third group, wherein the first feature of each group is the feature within the group disposed closest to the free end of the tool.