Twist drill with a pilot tip
US7520703B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 7, 2005 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Dec 28, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/9097
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An elongated drill bit has a shank at one end and working end at the other. A flute portion is between the working end and the shank. The flute portion is continuous with the shank and working end and is generally unitarily formed with them. The working end has a pilot tip with a first cutting portion. A second cutting portion is at the terminus of the flute portion and is axially spaced from the pilot tip first cutting portion. The second cutting portion includes a pair of cutting edges on opposing sides of the pilot tip. Each of the second cutting edges is on an angle from about 22° to 27° to a line transverse to the longitudinal axis. The cutting edges are defined by the junction of a rake face, defined by the flute surface, and a primary clearance face. Also, a secondary clearance face may be present which is continuous with the primary face at a different angle. The angle is about 50° to 65° with respect to the longitudinal axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.