SEGMENTED ORBITAL DRILL

• US 20120219371A1
• Filed: 02/24/2011
• Published: 08/30/2012
• Est. Priority Date: 02/24/2011
• Status: Active Grant

• Current Assignee: Kennametal Incorporated
• Original Assignee: Kennametal Incorporated
• Inventors: Craig, Karen Anne
• Granted Patent: US 8,858,129 B2
• Time in Patent Office: Days
• US Class Current: 408/1.R
• CPC Class Codes: B23B 2220/08 Deburring
• CPC Class Codes: B23B 2226/275 Carbon fibre reinforced carbon composites
• CPC Class Codes: B23B 2226/61 Plastics not otherwise provided for, e.g. nylon
• CPC Class Codes: B23B 2251/245 Variable cross sections
• CPC Class Codes: B23B 2251/60 Drills with pilots
• CPC Class Codes: B23B 2270/54 Methods of turning, boring or drilling not otherwise provided for
• CPC Class Codes: B23B 35/00 Methods for boring or drilling, or for working essentially requiring the use of boring or drilling machines; Use of auxiliary equipment in connection with such methods
• CPC Class Codes: B23C 2210/247 Stepped milling cutters
• CPC Class Codes: B23C 2210/70 Pilots
• CPC Class Codes: B23C 2220/52 Orbital drilling, i.e. use of a milling cutter moved in a spiral path to produce a hole
• CPC Class Codes: B23C 2226/27 Composites, e.g. fibre reinforced composites
• CPC Class Codes: B23C 3/02 Milling surfaces of revolution B23C3/06, B23C3/08 take precedence
• CPC Class Codes: B23C 5/10 Shank-type cutters, i.e. with an integral shaft
• CPC Class Codes: Y10T 407/19 Rotary cutting tool
• CPC Class Codes: Y10T 407/195 Compound tooth arrangement
• CPC Class Codes: Y10T 407/1962 Specified tooth shape or spacing
• CPC Class Codes: Y10T 408/03 Processes
• CPC Class Codes: Y10T 408/906 Axially spaced
• CPC Class Codes: Y10T 408/9065 with central lead
• CPC Class Codes: Y10T 409/303808 including infeeding

Abstract

A segmented orbital drill includes a segmented portion with a semi-finishing cutting portion and a plurality of finishing cutting portions. The semi-finishing cutting portion and finishing cutting portions are separated by grooves formed by a front wall and a rear wall. The segmented portion allows for a fresh cutting edge (i.e., rear wall of the groove) to be revealed as the orbital drill wears in the axial direction. The segmented portion also causes less contact with the workpiece, which reduces power consumption and minimizes deflection of the orbital drill. The segmented orbital drill also includes an optional pilot at one end of the drill, and a clearance neck portion between a shank and the segmented portion. A method of machining a workpiece using the segmented orbital drill is also disclosed.

Claims

1. A segmented orbital drill, comprising:

a segmented portion including a semi-finishing cutting portion and a plurality of finishing cutting portions, the semi-finishing cutting portion having a diameter that is different than a diameter of the plurality of finishing cutting portions; and

a clearance neck portion between the segmented portion and a shank.

2. The segmented orbital drill of claim 1, wherein the diameter of the semi-finishing cutting portion is less than the diameter of the plurality of finishing cutting portions.

3. The segmented orbital drill of claim 1, wherein the semi-finishing cutting portion and the plurality of finishing cutting portions is separated by a substantially V-shaped groove formed by a front wall, a rear wall and a radius therebetween.

4. The segmented orbital drill of claim 3, wherein the rear wall and the front wall form an angle with respect to each other.

5. The segmented orbital drill of claim 4, wherein the angle is about ninety degrees.

6. The segmented orbital drill of claim 3, wherein an angle formed by the front wall with respect to an axis perpendicular to a central, longitudinal axis of the segmented orbital drill is greater than an angle formed by the rear wall with respect to the axis that is perpendicular to the central, longitudinal axis.

7. The segmented orbital drill of claim 1, further comprising a pilot between the segmented portion and an end of the segmented orbital drill.

8. The segmented orbital drill of claim 7, wherein the pilot has a diameter smaller than the diameter of the segmented portion.

9. The segmented orbital drill of claim 7, further comprising an undercut between the pilot and the segmented portion.

10. The segmented orbital drill of claim 9, further comprising a tapered surface between the undercut and the segmented portion.

11. A method of machining a workpiece using a segmented orbital drill comprising a pilot and segmented portion and a clearance neck portion between the segmented portion and a shank, the method comprising:

drilling a hole in a first layer of material with the segmented portion of the segmented orbital drill;

drilling a hole in a second layer of material with the pilot while drilling the hole in the first layer of material with the segmented portion until the segmented portion has drilled completely through the first layer of material; and

drilling a hole in a third layer of material with the segmented portion without using the pilot until the segmented portion has drilled completely through the third layer of material.

12. The method of claim 11, further including the step of removing burrs from the hole using a tapered surface using a helical interpolation drilling operation or a circular drilling operation.