Drilling tool

Patent metadata

Field	Value
Publication number	US-2026034589-A1
Application number	US-202519275307-A
Country	US
Kind code	A1
Filing date	Jul 21, 2025
Priority date	Aug 5, 2024
Publication date	Feb 5, 2026
Grant date	—

Abstract

The present invention provides a tool for drilling, the tool comprising two or more cutting edges and a web thinning, in which a thinning heel surface facing backward in a rotating direction of the tool is formed by a convex surface, and in which a thinning angle gradually becomes smaller from a leading end of the tool toward a base end thereof. A thinning rake surface of the web thinning may be shaped straight so as to extend from an area around a center of the tool and in a radial direction or a parallel direction thereto in a tool front view. A thinning rake surface may be shaped in a helix in an opposite direction to the rotating direction of the tool so as to extend from an area around a center of the tool and in a radial direction in a tool front view.

First claim

What is claimed is:

1 . A tool for drilling, the tool comprising two or more cutting edges and a web thinning,
wherein a thinning heel surface facing backward in a rotating direction of the tool is formed by a convex surface, and wherein a thinning angle gradually becomes smaller from a leading end of the tool toward a base end thereof.

2 . The drilling tool according to claim 1 , wherein a thinning rake surface of the web thinning is shaped straight so as to extend from an area around a center of the tool and in a radial direction or a parallel direction thereto in a tool front view.

3 . The drilling tool according to claim 1 , wherein a thinning rake surface of the web thinning is shaped in a helix in an opposite direction to the rotating direction of the tool so as to extend from an area around a center of the tool and in a radial direction in a tool front view.

4 . The drilling tool according to claim 3 , wherein a curvature radius of the helix of the thinning rake surface is constant.

5 . The drilling tool according to claim 3 , wherein a curvature radius of the helix of the thinning rake surface is inconstant.

6 . The drilling tool according to claim 1 , wherein the thinning heel surface is formed along an arc about a predetermined location in a side view as seen perpendicularly to a central axis of the tool in a given direction.

7 . The drilling tool according to claim 6 , wherein a curvature radius y of the thinning heel surface is a value obtained through y=ax+b with respect to a tool diameter x.

8 . The drilling tool according to claim 1 , wherein the number of web thinnings is equal to the number of cutting edges.

9 . The drilling tool according to claim 1 , wherein a plurality of web thinnings are uniformly arranged at regular intervals in a circumferential direction.

10 . The drilling tool according to claim 1 , wherein the drilling tool is a head exchangeable drill comprising a body and a head that is removable with respect to the body, wherein the head is provided with the cutting edges.

11 . The drilling tool according to claim 10 , wherein the thinning heel surface of the head protrudes further backward with respect to the rotating direction of the tool than a back metal of the body.

Assignees

• Tungaloy Corp

Inventors

• Komatsu Naoki

Classifications

• B23B2251/182

  Web thinning · CPC title

• B23B2222/80

  Stainless steel · CPC title

• B23B51/0003

  with exchangeable heads or inserts · CPC title

• B23B51/02 Primary

  Twist drills · CPC title

• B23B2251/14

  Configuration of the cutting part, i.e. the main cutting edges · CPC title