Drill bit with an exchangeable cutting portion

Patent metadata

Field	Value
Publication number	US-10201860-B2
Application number	US-201314654461-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 is disclosed. The drill bit has a cutting portion having an annular portion, where the annular portion has a first end on which is disposed a cutting element and a second end that includes an outer insertion element and a stop shoulder. The drill bit has a drill shaft portion having a cylindrical drill shaft, where the drill shaft has an inner insertion element with an end face on a side of the drill shaft facing the cutting portion. 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 the insertion elements are connectable to each other via a pin element that is movable into a slot-shaped recess. The pin element is attached to an outside of the inner insertion element and the outer insertion element has the slot-shaped recess.

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, an outer insertion element, and an annular limit stop shoulder, wherein the cutting element is disposed on a first end of the annular portion, wherein the outer insertion element is disposed on a second end of the annular portion, and wherein the annular limit stop shoulder is 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 on a first end of the inner insertion element and has an end face on a second end of the inner insertion element facing 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 movable into a slot-shaped recess;
wherein the pin element is attached to an outside of the inner insertion element, wherein the slot-shaped recess is formed in the outer insertion element, and wherein in a connected state of the drill bit, the end face of the inner insertion element is in contact with the annular limit stop shoulder of the cutting portion; and
wherein a lug is disposed on the outside of the inner insertion element, wherein the outer insertion element has a groove, and wherein the lug and the groove form a form-fitting connection in a connected state in an axial direction.

2. 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.

3. The drill bit according to claim 2 , wherein the length of the outer insertion element is at least 18 mm.

4. The drill bit according to claim 3 , wherein the length of the outer insertion element is no greater than 28 mm.

5. The drill bit according to claim 1 , wherein the outer insertion element and the inner insertion element are formed as a ring, wherein a difference between an inside diameter of the outer insertion element and an outside diameter of the inner insertion element is greater than 0.11 mm.

6. The drill bit according to claim 1 , wherein one or more additional pin elements are attached to the outside of the inner insertion element, wherein the outer insertion element has one or more additional slot-shaped recesses, and wherein a number of the slot-shaped recesses is greater than or equal to a number of the pin elements.

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

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

9. The drill bit according to claim 1 , wherein the slot-shaped recess has a cross-slot perpendicular to the axis of rotation and wherein the cross-slot is connected to an upper edge of the outer insertion element via a connecting slot.

10. The drill bit according to claim 9 , wherein the cross-slot has a distance parallel to the axis of rotation from an edge of the annular portion of at least 3 mm.

11. The drill bit according to claim 10 , wherein the distance is no greater than 5 mm.

12. The drill bit according to claim 9 , wherein a height of the connecting slot parallel to the axis of rotation is at least 10 mm.

13. The drill bit according to claim 12 , wherein the height of the connecting slot parallel to the axis of rotation is no greater than 13 mm.

14. The drill bit according to claim 9 , wherein the cross-slot has a follower region and a securing region, wherein the follower region is disposed on a first side of the connecting slot and wherein the securing region is disposed on a second side of the connecting slot.

15. The drill bit according to claim 14 , wherein a width of the follower region is no less than a radius of the pin element plus 1.5 mm.

16. The drill bit according to claim 15 , wherein the width of the follower region is no greater than the radius of the pin element plus 3 mm.

17. The drill bit according to claim 14 , wherein a width of the follower region and a width of the securing region are equal.

18. The drill bit according to claim 14 , wherein a width of the follower region is greater than a width of the securing region.

19. The drill bit according to claim 1 , wherein the annular portion has a guide portion, wherein the guide portion is in flush contact with an outer edge, an inner edge, or the outer edge and the inner edge of the cutting element parallel to the longitudinal axis.

20. The drill bit according to claim 19 , wherein a length of the guide portion is less than 4 mm parallel to the axis of rotation.

21. The drill bit according to claim 1 , wherein the lug is disposed between the pin element and the drill shaft in the axial direction and wherein the groove is disposed at a height of the slot-shaped recess in the axial direction.

22. The drill bit according to claim 1 , wherein the groove is ring-shaped and is disposed in a plane perpendicular to the axis of rotation.

Assignees

• Hilti Ag

Inventors

• Hoop Matthaeus
• Weber Christoph
• Britt Thomas
• Amman Christoph

Classifications

• B23B2240/04

  Bayonet connections · CPC title

• B23B51/0466

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

• B23B51/0473 Primary

  Details about the connection between the driven shaft and the tubular cutting part; Arbors · CPC title

• B23B51/0406

  Operations & Transport · mapped topic

• Y10T408/8953

  with lateral outlet · CPC title