Patent ID: 8251112

Claim:
A cutterhead for a peripheral milling machine, said cutterhead comprising: (a) a cutterhead body including (i) a generally cylindrical portion and (ii) a plurality of circumferential, spaced and offset blade unit mounting cavities extending into the cutterhead body from the periphery of the cylindrical portion in a helical arrangement for receiving a blade unit; and (b) a plurality of blade units each having at least one cutting edge aligning in said helical arrangement to form a substantially continuous helical cutting edge, whereby said cutting edge of each of said blade units is disposed to align with the cutting edge of each of the other blade units in adjacent mounting cavities to form a substantially helical, stepped blade row having said substantially continuous helical cutting edge when said blade units are secured to said cutterhead body at a tilt angle between about 2 and about 20 degrees and a shear angle greater than zero to align said cutting edge of each of said blade units in said substantially continuous helical cutting edge; wherein said tilt angle is measured from said blade unit to an axis perpendicular to a rotational axis of said cutterhead and is inversely proportional to the diameter of said cutterhead; wherein said shear angle is measured from said at least one cutting edge of said blade unit to said rotational axis and is inversely proportional to an axial offset between said blade unit and an adjacent blade unit.