Step drill bit
US11273501B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2019 |
| Grant date | Mar 15, 2022 |
| Priority date | — |
| Expiry date | Apr 18, 2039 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23B2251/242
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A drill bit includes a shank extending along a bit axis and a body with a proximal end adjacent the shank and a distal end opposite the proximal end. The body defines a plurality of axially stacked, progressively sized steps including a first step at the distal end and a terminal step at the proximal end. The drill bit also includes a flute in the body. The flute defines an elongated groove that extends from the distal end to the proximal end. The drill bit further includes a plurality of cutting edges formed in the body. Each cutting edge is disposed along one of the plurality of steps and defines a helix angle and a rake angle. The helix angle of the cutting edge at the terminal step is greater than the helix angle of the cutting edge at the first step. A ratio of the helix angle to the rake angle of the cutting edge at the first step is in a range from 0.5 to 2.4, and a ratio of the helix angle to the rake angle of the cutting edge at the terminal step is in a range of 0.9 to 1.7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.