Metal cutting insert for a drill tool and a drill tool

Patent metadata

Field	Value
Publication number	US-12521802-B2
Application number	US-202118013223-A
Country	US
Kind code	B2
Filing date	Apr 21, 2021
Priority date	Jul 1, 2020
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A metal cutting drill insert for a drill tool has opposing top and bottom surfaces with a symmetry axis extending therebetween. At least one stepped cutting edge is configured to cut a continuous chip along the at least one stepped cutting edge. The at least one stepped cutting edge is formed at an intersection of a rake face and an adjoining clearance face of the side surface. In a top view facing the top surface the at least one stepped cutting edge includes a step formed by a transitional edge between a first part and a second part edge. The step extends in a radial direction relative the symmetry axis by a first distance h1, and in a side view facing the side surface the step extends in a direction from the bottom surface towards the top surface by a second distance h2, wherein 0.8·h1≤h2≤1.2·h1.

First claim

The invention claimed is:

1 . A metal cutting drill insert for a drill tool comprising:
opposed top and bottom surfaces and an axis of the cutting drill insert extending there between, wherein a peripheral side surface extends between the top surface and the bottom surface, and wherein the top surface includes a rake face and the side surface includes a clearance face; and at least one stepped cutting edge configured to cut a continuous chip along said at least one stepped cutting edge, wherein said at least one stepped cutting edge is formed at an intersection of the rake face of the top surface and the clearance face of the side surface, the rake face adjoining the clearance surface, wherein in a top view facing the top surface of the metal cutting insert, said at least one stepped cutting edge includes a step formed by a transitional edge disposed between a first part edge and a second part edge, wherein in the top view facing the top surface of the metal cutting insert said step extends in a radial direction to from the axis by a first distance h1, and in a side view facing the peripheral side surface of the metal cutting insert said step extends from the bottom surface towards the top surface by a second distance h2, wherein 0.8·h1≤h2≤1.2·h1, wherein the transitional edge has a curved edge, and wherein the curved edge has a same shape in the top view and the side view.

2 . The metal cutting drill insert according to claim 1 , wherein said second distance h2 is 0.9·h1≤h2≤1.1·h1.

3 . The metal cutting drill insert according to claim 1 , wherein said second distance h2 is 0.95·h1≤h2≤1.05·h1.

4 . The metal cutting drill insert according to claim 1 , wherein said stepped cutting edge includes a corner edge connected to the first part edge, and wherein said corner edge is connected to a second part edge of a further stepped cutting edge of the insert.

5 . The metal cutting drill insert according to claim 1 , wherein the corner part edge provides a continuous edge from the first part edge of the stepped cutting edge to said second part edge of the further stepped cutting edge.

6 . The metal cutting drill insert according to claim 1 , wherein said transitional edge has a curved edge, wherein the curved edge has a same shape in said top view and said side view.

7 . The metal cutting drill insert according to claim 1 , further comprising a through hole extending between the top surface and the bottom surface of the insert, wherein the through hole is aligned along said axis and extends through the opposing top and bottom surfaces.

8 . The metal cutting drill insert according to claim 1 , wherein a plurality of stepped cutting edges are arranged symmetrically around said axis.

9 . The metal cutting drill insert according to claim 1 , wherein the step extends in a positive radial direction relative to the axis in the top view when moving along said stepped cutting edge in a counter-clockwise direction around said metal cutting drill insert.

10 . A metal cutting drill tool comprising:
an elongated drill body having a boring shaft and a mount shank; and at least one drill insert according to claim 1 mounted at an end of the boring shaft.

Assignees

• Sandvik Coromant Ab

Inventors

• Carlberg Hakan
• Harstrom Patrik

Classifications

• B23B2200/24

  Cross section of the cutting edge · CPC title

• B23B51/00

  Tools for drilling machines · CPC title

• B23B2200/204

  with discontinuous cutting edge · CPC title

• B23B2200/126

  stepped · CPC title

• B23B2200/085

  discontinuous · CPC title