Twist Drill
US6315504A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1999 |
| Grant date | Nov 13, 2001 |
| Priority date | — |
| Expiry date | Oct 27, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/9097
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An improved twist drill is provided which reduces wear or chippings of the major cutting edges (3) and those of the leading edges (7) of land (9) and which has a long service life and stays sharp. A twist drill has a pair of chip discharge flutes (6), a pair of chisel edges (1), a pair of inner cutting edges (2) and a pair of major cutting edges (3) extending from each outer end of the inner cutting edges (2). Further, the drill has a pair of outer cutting edges (4) each receding from each of the major cutting edges (3) at an angle (.alpha.1), and a pair of leading edges (7) of lands (9) each formed by the land (9) and the outer cutting edge (4) and has a linear or curved rake face (8). Wherein, an angle (.alpha.4) of the leading edge (7) of land (9) between the leading edge (7) of the land (9) between the leading edge (7) of the land (9) and the linear or curved rake face (8) is an obtuse angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.