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US 2019/0299302 A1Published application
Drill
AssigneeToko, Inc.
InventorMakoto TERASHIMA
Life of this patent
Estimating the term…
Abstract
A drill includes a tip cutting edge provided at a tip end thereof and a main cutting edge continuous to a rearward of the tip cutting edge. A point angle of the tip cutting edge is a predetermined acute angle. A point angle of the main cutting edge decreases from a front end toward a rear end of the main cutting edge. A point angle at the front end of the main cutting edge is an acute angle greater than the point angle of the tip cutting edge.
Claims4
A drill comprising:
- a tip cutting edge provided at a tip end;
- and
- a main cutting edge connected to a rearward of the tip cutting edge,
- wherein a point angle of the tip cutting edge is a predetermined acute angle,
- a point angle of the main cutting edge decreases from a front end toward a rear end of the main cutting edge,
- a point angle at the front end of the main cutting edge is an acute angle greater than the point angle of the tip cutting edge, and
- a part at which the tip cutting edge is connected to the main cutting edge, is bent in a direction of being away from a center axis of the drill from the tip cutting edge toward the main cutting edge.
4 more elements
Dependencies are inferred from the claim text.