Patent ID: 7467915

Claim:
A cutting tool assembly for conducting rotary cutting operations on a work piece, comprising a tool shank and a replaceable cutting head which is installed on and engages the tool shank, the tool shank and the cutting head having a common rotational axis and complimentary peripheral surfaces when assembled together, the cutting tool assembly having a leading end which engages the work piece and a trailing end located oppositely from the leading end, relative to the rotational axis; the shank having a pocket for coupling to the cutting head, an interlocking member arranged to retain the cutting head when the cutting head is installed within the pocket, at least one abutment surface abutting the cutting head when the cutting head is installed within the pocket, and at least one driving surface arranged to rotate the cutting head when the shank is rotated with the cutting head installed within the pocket; the cutting head having, a peripheral base surface facing the pocket and a dovetail member located centrally along the common rotational axis, the dovetail member having a lateral surface oriented at an obtuse angle to the rotational axis, a cutting portion at the leading end of the cutting tool assembly, and a shank connection portion opposite the cutting portion and facing the trailing end of the shank connection portion, a corresponding interlocking member for engaging the interlocking member of the shank, a cutting head abutment surface abutting the shank when the cutting head is installed within the pocket, and a driven surface oriented to abut the driving surface of the shank when the cutting head is installed within the pocket; wherein the pocket has at least one internally facing surface oriented to abut the lateral surface of the dovetail member of the cutting head, the internally facing surface being dimensioned and configured to abut the dovetail member of the cutting head along part of the extent of the lateral surface of the dovetail member and to avoid making contact along the balance of the lateral surface of the dovetail member, whereby the uncontacted portion of the pocket allows for deflection of the pocket walls when forces are imposed on the pocket by the cutting head during cutting operations of the cutting tool, thereby mitigating radial deflection of the pocket walls.