Patent ID: 7708038

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 for receiving a blade unit; and (b) a plurality of blade units each having at least one 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 when said blade units are secured to said cutterhead body, whereby the minimum offset to provide an overlapping corner of an adjacent blade unit cutting edge is a function of the shear angle orientation of the blades and the geometry of the blade units, wherein the minimum offset is calculated according to the function Minimum Offset equals (w′)(tangent(90°−shear angle°)); where w′ is the blade unit width dimension and the shear angle is the angle formed by the blade unit and the rotational axis of the cutterhead, whereby each helical stepped blade row makes a full cut.