Drill bit with an exchangeable cutting portion

Patent metadata

Field	Value
Publication number	US-10201858-B2
Application number	US-201314654459-A
Country	US
Kind code	B2
Filing date	Dec 20, 2013
Priority date	Dec 21, 2012
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A drill bit, which is rotatable in a direction of rotation about an axis of rotation, is disclosed. The drill bit has a cutting portion with an annular portion where the annular portion has a first end on which is a cutting element and has at a second end a first insertion element. The drill bit has a drill shaft portion with a cylindrical drill shaft which has at an end, towards the cutting portion, a second insertion element. In a direction of insertion parallel to the axis of rotation, the insertion elements form a plug-in connection and can be additionally connected by way of at least one pin element which is movable in at least one slit-shaped clearance.

First claim

The invention claimed is:

1. A drill bit that is rotatable in a rotational direction around an axis of rotation, comprising:
a cutting portion having an annular portion, a cutting element connected on a first end of the annular portion, an outer insertion element connected on a second end of the annular portion, and an annular limit stop shoulder disposed at a transition from the annular portion to the outer insertion element; and
a drill shaft portion having a cylindrical drill shaft and an inner insertion element, wherein the inner insertion element is connected to the cylindrical drill shaft at a first end and has an abutting face at a second end;
wherein in a connected state the abutting face of the inner insertion element is in flush contact with the annular limit stop shoulder of the cutting portion, wherein the outer insertion element and the inner insertion element together form a plug connection in an insertion direction that is parallel to the axis of rotation and wherein the outer insertion element and the inner insertion element are connectable to each other via a pin element that is attached to an outside of the inner insertion element and is movable into a slit-shaped clearance in the outer insertion element;
wherein the slit-shaped clearance includes a connector slit and a transverse slit having a catching region and a locking region, wherein the catching region is disposed on a first side of the connector slit and the locking region is disposed on a second side of the connector slit; and
wherein a nose is disposed on the outside of the inner insertion element, wherein the outer insertion element includes a groove, and wherein the nose and the groove form a positive connection in an axial direction in the connected state.

2. The drill bit according to claim 1 , wherein a height of the connector slit parallel to the axis of rotation is at least 10 mm.

3. The drill bit according to claim 2 , wherein the height of the connector slit parallel to the axis of rotation does not exceed 13 mm.

4. The drill bit according to claim 1 , wherein the transverse slit has a distance parallel to the axis of rotation from a lower edge of the annular portion of at least 3 mm.

5. The drill bit according to claim 4 , wherein the distance parallel to the axis of rotation from the lower edge of the annular portion does not exceed 5 mm.

6. The drill bit according to claim 1 , wherein the pin element has a pin height perpendicular to the axis of rotation that is 68% to 89% of a width of the drill shaft.

7. The drill bit according to claim 1 , wherein the pin element is cylindrical with a pin radius that is between 2.5 and 5 mm.

8. The drill bit according to claim 7 , wherein a width of the catching region is not less than the pin radius plus 1.5 mm.

9. The drill bit according to claim 8 , wherein the width of the catching region does not exceed the pin radius plus 3 mm.

10. The drill bit according to claim 8 , wherein the width of the catching region is greater than a width of the locking region.

11. The drill bit according to claim 8 , wherein the width of the catching region and a width of the locking region are equal.

12. The drill bit according to claim 1 , wherein a length of the inner insertion element is greater than a length of the outer insertion element.

13. The drill bit according to claim 12 , wherein the length of the outer insertion element is at least 18 mm.

14. The drill bit according to claim 13 , wherein the length of the outer insertion element does not exceed 28 mm.

15. The drill bit according to claim 1 , wherein the outer insertion element and the inner insertion element are annular with a difference between an inner diameter of the outer insertion element and an outer diameter of the inner insertion element being greater than 0.11 mm.

16. The drill bit according to claim 15 , further comprising one or more additional pin elements that are attached to the outside of the inner insertion element and further comprising one or more additional slit-shaped clearances, wherein a number of the slit-shaped clearances is greater than or equal to a number of the pin elements.

17. The drill bit according to claim 1 , wherein the annular portion includes a guide portion, wherein the guide portion rests flush against an outer edge, an inner edge, or against the outer edge and the inner edge of the cutting element parallel to the longitudinal axis.

18. The drill bit according to claim 17 , wherein a length of the guide portion parallel to the axis of rotation is less than 4 mm.

19. The drill bit according to claim 1 , wherein the nose is disposed in the axial direction between the pin element and the drill shaft and wherein the groove is disposed in the axial direction at a level of the slit-shaped clearance.

20. The drill bit according to claim 1 , wherein the groove is annular and is disposed in a plane perpendicular to the axis of rotation.

Assignees

• Hilti Ag

Inventors

• Hoop Matthaeus

Classifications

• B23B51/0466

  with exchangeable cutting inserts, e.g. able to be clamped · CPC title

• E21B10/62

  characterised by parts, e.g. cutting elements, which are detachable or adjustable (E21B10/64 takes precedence; for roller bits E21B10/20; for augers E21B10/44) · CPC title

• B23B2251/428

  Operations & Transport · mapped topic

• B23B2240/04

  Bayonet connections · CPC title

• E21B17/046

  with ribs, pins, or jaws, and complementary grooves or the like, e.g. bayonet catches · CPC title