Michael J Mealey

US Patent:

57589976, Jun 2, 1998

Filed:

Aug 7, 1996

Appl. No.:

8/689220

Inventors:

Michael Mealey - Oak Ridge TN
Benjamin D. Greenwell - Knoxville TN

International Classification:

B23B 5102

US Classification:

408224

Abstract:

A self-centering indexable drill having cutting inserts disposed such that cutting forces on the inboard and outboard flutes of the drill body are substantially equal while boring a hole, thereby keeping the drill body substantially centered. The drill includes a drill body and a plurality of cutting inserts. The drill body includes a shank portion configured to be received by the spindle of a machine using the drill, a collar, and a fluted portion. The fluted portion of the drill body defines an inboard flute and an outboard flute. At least one cutting insert is releasably secured to each of the inboard and outboard flutes, with an equal number of cutting inserts carried by each. An insert pocket is defined by the drill for closely receiving each cutting insert such that the leading face of the cutting insert is substantially flush with the face of the flute. The cutting inserts are spaced on the inboard and outboard flutes such that as the drill bores a workpiece, the material removed by the cutting inserts on the inboard flute is equal to that removed by the cutting inserts on the outboard flute. The exposed cutting edge of the innermost inboard cutting insert is disposed at a first angle with respect to a line normal to the axis of rotation.