Self-centering drill bit with pilot tip
US7267514B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 2004 |
| Grant date | Sep 11, 2007 |
| Priority date | — |
| Expiry date | Sep 7, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/9097
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An elongate drill bit (20) with a longitudinal axis (X-X) has a shank (28), a working end (24), and a fluted section (26) between the shank and the working end. The shank, the working end and the fluted section are all formed integrally in the drill bit. The working end has an outer cutting portion (34) and a central pilot tip (36) which extends axially ahead of the outer cutting portion. The pilot tip is formed with at least one pair of minor cutting edges (40, 42; 44, 46) arranged on opposite sides of the axis. The outer cutting portion is formed with a pair of major cutting edges (70, 72) arranged on opposite sides of the axis. The outer cutting portion has a major diameter (D) defined by the pair of major cutting edges. The pilot tip has a minor diameter (d) defined by the at least one pair of minor cutting edges. The fluted section has a pair of helical lands (32) each with a respective inner surface (92) extending axially rearward from one of the major cutting edges and from one of the minor cutting edges. The helical lands define a web (94). Each helical land defines a respective helical flute (30). The helical lands have a pitch (S) and the web has a web thickness (K) at th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.