Drill having construction suitable for enlarging previously formed hole
US7422396B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 4, 2005 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Nov 6, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/9097
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A drill which includes a cylindrical main body and a shank contiguous to each other, and which is to be rotated about an axis of the cylindrical main body in a predetermined rotating direction, for enlarging a hole previously formed in a workpiece through a die-casting process. The cylindrical main body has flutes which are formed in the cylindrical mainbody and extend from an axially distal end portion of the cylindrical main body toward the shank, so as to provide cutting edges in the axially distal end portion of the cylindrical main body. The cutting edges cooperate with each other to define a point angle which is larger than 170° and is smaller than 180°. Each of the cutting edges is substantially straight or is curved to be convexed as seen in the direction perpendicular to the axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.