High speed metal drill bit

• US 20060029477A1
• Filed: 08/09/2004
• Published: 02/09/2006
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Black & Decker Incorporated (Stanley Black & Decker, Inc.), University of Maryland
• Original Assignee: University of Maryland
• Inventors: Rescigno, Gerald, Xu, Li, Thomas, Rickey J., Anjanappa, Muniswamappa, Crosby, Stephen R., Timmons, Russell M.
• Granted Patent: US 7,237,986 B2
• Time in Patent Office: Days
• US Class Current: 408/230
• CPC Class Codes: B23B 2251/04 Angles, e.g. cutting angles
• CPC Class Codes: B23B 2251/043 Helix angles
• CPC Class Codes: B23B 2251/14 Configuration of the cutting part, i.e. the main cutting edges
• CPC Class Codes: B23B 51/02 Twist drills
• CPC Class Codes: Y10T 408/909 Having peripherally spaced cutting edges
• CPC Class Codes: Y10T 408/9097 Spiral channel

Abstract

A metal cutting drill bit has a shank portion, a flute portion defining a helix angle and a tip. The tip has a primary cutting edge extending to an outer periphery of the drill bit. The primary cutting edge has a rake face defining a rake angle. The rake angle is different from the helix angle at the tip of the drill bit.

Claims

1. A metal cutting drill bit comprising:

a shank portion;

a flute portion, said flute portion defining a helix angle; and

a tip, said tip including a primary cutting edge extending to an outer periphery of the drill bit, said primary cutting edge defined by a rake face, said rake face defining a rake angle, said rake angle being different from said helix angle at said tip.

2. The drill bit according to claim 1 wherein an egress surface is between said rake surface and said flute at said tip.

3. The drill bit according to claim 1 wherein said tip has a secondary cutting edge.

4. The drill bit according to claim 1 wherein said rake surface has a desired length dependent on the diameter of said drill bit.

5. The drill bit according to claim 1 wherein said egress face is on a desired angle to enhance chip removal.

6. The drill bit according to claim 1 wherein said drill bit has a pair of primary cutting edges.

7. The drill bit according to claim 6 wherein said pair of primary cutting edges define a primary point angle of between 90°

and 150°

.

8. The drill bit according to claim 6 wherein said drill bit has a pair of secondary cutting edges.

9. The drill bit according to claim 8 wherein said pair of secondary cutting edges define a secondary point angle of between 120°

and 165°

.

10. A metal cutting drill bit comprising:

a shank;

a flute; and

a tip, said tip having at least one primary cutting edge, said cutting edge defined by a rake surface, said rake surface extending from said cutting edge a desired length, an egress surface continuous with said rake surface, said egress surface extending outward from said rake surface and said egress surface continuous with a flute surface such that said flute surface and rake surface extend axially along the drill bit.

11. The drill bit according to claim 10 wherein said rake surface and said flute surface define different angles.

12. The drill bit according to claim 11 wherein said rake surface angle is between 15°

and 45°

.

13. The drill bit according to claim 11 wherein said flute surface angle is between 10°

and 40°

.