Patent ID: 6585459
Filing Date: 2003-07-01
Classification: B23B,Y10T

Abstract:
A plug cutter rotatable about an axis of rotation, comprising:a main body having a longitudinal axis coinciding with said axis of rotation; a shank extending axially from one end of said main body, concentrically with said axis of rotation; and a plurality of cutting blades extending axially from an opposite end of said main body and terminating in a distal end, each of said blades having a leading edge and an inner surface facing generally radially inwardly, said plurality of blades being adapted to cut a plug in a piece of stock as said main body is rotated about said axis of rotation and advanced axially of the piece of stock, wherein said plurality of cutting blades are constructed and arranged so that when said main body is rotated, said plurality of blades define a bore that is tapered along at least a portion of the length thereof in at least first and second stages, at least first and second angles, respectively, such that a radial distance between said leading edge and said axis of rotation is greater adjacent said distal end than adjacent said main body, said first stage of said taper being defined adjacent said distal end and said second stage of said taper being defined proximal of the first stage, and said first angle of said first stage of said taper differing from said second angle of said second stage of said taper, each said angle being greater than zero with respect to said longitudinal axis.