Drill bit

Patent metadata

Field	Value
Publication number	US-10947788-B2
Application number	US-201716095174-A
Country	US
Kind code	B2
Filing date	Apr 19, 2017
Priority date	Apr 21, 2016
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A drill bit that serves to remove mineral materials and that consecutively has on a longitudinal axis ( 6 ) a drill head ( 2 ), a helix ( 3 ), an insertion end ( 4 ) and an impact surface ( 7 ) on the end face of the insertion end ( 4 ) that faces away from the drill head ( 2 ) and that serves to absorb impact along a direction of impact ( 8 ), is provided. The drill head ( 2 ) has at least two cutting edges ( 13 ) and at least two blades ( 20 ). The cutting edges ( 13 ) each have a cutting face ( 16 ) and a free face ( 17 ). The blades ( 20 ) run parallel to the longitudinal axis ( 6 ) and adjoin the cutting edges ( 13 ). The blades ( 20 ) each have a radially projecting tooth ( 24 ) that adjoins the cutting face ( 16 ), whereas it adjoins the free face ( 17 ) either only partially or not at all. The axial dimension ( 29 ) of the tooth ( 24 ) is smaller than the axial dimension ( 25 ) of the blade ( 20 ).

First claim

What is claimed is:

1. A drill bit serving to remove mineral materials, the drill bit consecutively on a longitudinal axis comprising:
a drill head;
a helix; and
an insertion end, an impact surface on an end face of the insertion end facing away from the drill head, the impact surface serving to absorb impact along a direction of impact;
the drill head having at least two cutting edges and at least two blades, the cutting edges each have a cutting face and a free face and the blades running parallel to the longitudinal axis and adjoining the cutting edges,
the blades each have a radially projecting tooth adjoining the cutting face, the radially projecting tooth not adjoining the free face, and an axial dimension of the tooth being smaller than a blade axial dimension of the blade.

2. The drill bit as recited in claim 1 wherein the blades have a blade free face arranged in front of the tooth in the direction of impact and in front of the tooth in the direction of rotation, a radial distance of the blade free face to the longitudinal axis being smaller than a tooth radial distance of the tooth to the longitudinal axis.

3. The drill bit as recited in claim 2 wherein the blade free face is configured so as to have a partially cylindrical surface.

4. The drill bit as recited in claim 1 wherein the tooth has a partially cylindrical outer surface.

5. The drill bit as recited in claim 4 where a radius of the partially cylindrical outer surface is the same as a radial distance to the longitudinal axis of the drill bit.

6. The drill bit as recited in claim 1 wherein the tooth adjoins a concave inner surface defining a removal groove for drill cuttings.

7. The drill bit as recited in claim 1 wherein that the axial dimension of the tooth amounts to between 50% and 80% of the blade axial dimension.

8. The drill bit as recited in claim 1 wherein the at least two cutting edges are monolithically joined to two additional cutting edges.

9. The drill bit as recited in claim 8 wherein the two additional cutting edges have smaller radial dimensions than the at least two cutting edges, and a continuously prismatic or cylindrical secondary cutting blade to the longitudinal axis is configured adjacent to each of the two additional cutting edges.

10. The drill bit as recited in claim 1 wherein the drill head is made of sintered metal carbide and the helix is made of steel.

11. The drill bit as recited in claim 6 wherein the removal groove transitions into a helical groove of the helix.

12. The drill bit as recited in claim 1 wherein the helix has a plurality of helical grooves.

13. The drill bit as recited in claim 1 wherein the drill head as two secondary cutting edges, a radius of the free face corresponding to a radius of the secondary cutting edges.

14. The drill bit as recited in claim 13 wherein the tooth has an outer surface offset radially between 0.2 mm and 1.0 mm vis-à-vis the free face.

15. The drill bit as recited in claim 1 wherein a height of the tooth is in a range between 50% and 80% of a height of the blade.

Assignees

• Hilti Ag

Inventors

• Domani Guenter
• Pluemacher Bastian
• Foser Roland

Classifications

• B23B51/02 Primary

  Twist drills · CPC title

• B23B2251/44

  Margins, i.e. the narrow portion of the land which is not cut away to provide clearance on the circumferential surface · CPC title

• B23B2200/121

  with projections · CPC title

• B28D1/146

  Tools therefor (drill bits for earth or rock drilling E21B10/00) · CPC title

• E21B10/445 Primary

  percussion type, e.g. for masonry · CPC title