Drill having construction for reducing thrust load in drilling operation, and method of manufacturing the drill
US6923602B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2002 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Jan 5, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/9097
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A drill including a shank portion and a cylindrical body portion contiguous to each other. The cylindrical body portion includes (a) primary cutting edges and secondary cutting edges formed in its axially distal end portion such that each of the secondary cutting edges is located on a radially inner side of the corresponding primary cutting edge; (b) primary rake surfaces of the primary cutting edges and secondary rake surfaces of the secondary cutting edges; and (c) inclined surfaces each of which extends from the corresponding secondary rake surface to a periphery of the cylindrical body portion, and is inclined such that an axial distance between each of the inclined surfaces and the shank portion is reduced as viewed in a direction substantially perpendicular to the corresponding secondary cutting edge, from the corresponding secondary rake surface toward the periphery of the cylindrical body portion. Each of the secondary rake surfaces and the corresponding secondary cutting edge are formed together with each other in a web thinning. Each of the secondary rake surfaces and the corresponding inclined surface are connected to each other without a step therebetween.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.