High speed milling cutter

Abstract

A milling cutterhead provided with slots for receiving indexable, disc-shaped cutting bits mounted in individual nest plates. The cutterhead is a generally cylindrical body comprising two concentric body parts, namely, a main member having a circumferential rim portion and an interior ring member which mates with and fits tightly within that rim portion. The nest-receiving slots are cut through the full radial width of the rim portion, and the outer circumference of the interior ring forms the inner walls of the slots. Each nest plate supports more than one-half the circumference of its respective indexable bit at three or more spaced locations so that any inserted bit, no matter how indexed, will have either its radial or axial diameter substantially aligned in a predetermined plane, thereby assuring that the cutting edge of each indexable disc-shaped bit will be positioned to an axial or radial accuracy equal to or less than one-half the diametral tolerance for such disc-shaped bits. With such assured accuracy, no further truing of the individual bits is required when they are indexed. Further, the interior ring design of the cutterhead reduces the probability of stress-related failures and provides increased rigidity needed for high-speeding cutting, and separate tightening wedges permit cutting discs to be readily indexed and/or changed without disturbing the nest plates and without necessitating further truing of such indexed or newly-inserted bits.