US 4,565,472 AGrant
Drill for Hand-Held Drilling Devices
Issue Date:1986-01-21
•10 Claims
•1 Drawing Sheets
Abstract
A drill is secured in percussion drilling machines and in tool holders of hammer drills by locking elements. The locking elements fit into axially extending grooves formed in the axially extending circumferential surface of the shank of the drill. Webs located intermediate the ends of the grooves divide the grooves into axially extending groove sections with the locking elements fitting into the groove sections. The outer surfaces of the webs are located in the circumferential surface of the shank and serve to support the jaws of the tool holder in the correct position.
Metadata
Assignee
- Hilti Aktiengesellschaft
Inventors
- Ernst Brennsteiner
- Dieter Scholz
Application Information
Application Number:US 7272073
Filing Date:1985-04-29
Priority Date:1981-11-11
Art Unit:322
Classifications
IPC:
B23B 5100B23B 3108E21B 1036
Field of Search:
408173175279226;199132414;41519.1;19.2;19.3;19.4;19.5;19.6;19.7;19;76;77;83;84;85
Patent Drawings (1 sheets)
Description
BRIEF DESCRIPTION OF THE DRAWING
In the drawing
FIG. 1 is an elevational view, partly in section, illustrating a drill, embodying the present invention, and having three axially extending grooves each of which has a rounded base in transverse cross section;
FIG. 2 is a similar view of another embodiment of a drill incorporating the present invention where the axially extending grooves are V-shaped in transverse section; and
FIG. 3 is a sectional view of the drill shown in FIG. 2 taken along the line III--III.
SUMMARY OF THE INVENTION
In FIG. 1 a drill 1 is illustrated made up of an axially extending working or cutting end 2 and an axially extending shank 3. The leading end of the drill is formed by the cutting end 2 and the trailing end by the shank 3. In the shank 3, three axially extending grooves 4 are spaced angularly apart around the circumferentially extending surface of the shank. The grooves 4 have a rounded or circular base. Each groove 4 is divided by a pair of axially spaced and axially extending webs 5 into three serially arranged axially extending groove sections 4a, 4b, 4c. The surface of the webs form a continuation of the circumferential surface of the shank 3.
The adjacent end of the axially extending groove 4 is spaced from the trailing end face 3a of the shank 3 by a distance A. The distance A corresponds to 0.4 times the diameter D of the shank. The axial length B of the web 5 is 0.6 times the diameter D of the shank. Each axially extending groove section 4a, 4b, 4c has the same length L and in the illustrated embodiment the length L is 0.8 times the diameter D of the shank 3. The maximum depth T of the axially extending groove sections 4a, 4b, 4c corresponds in the illustrated embodiment to 0.2 times the diameter D of the shank 3.
In FIG. 2 another embodiment of the invention is shown including a drill 11 with an axially extending working or cutting end 12 and an axially extending shank 13. Three angularly spaced axially extending grooves 14 are formed in the circumferentially extending surface of the shank 13. Each of the grooves is divided by means of a web 15 into a pair of axially extending groove sections 14a, 14b. As shown in FIG. 3, the groove sections each have a V-shaped transverse section. The V-shaped groove sections 14a, 14b have axially extending sides 16 and the sides enclose an angle .alpha. which in the illustrated embodiment is 100.degree..
The dimension A between the trailing end face 13a and the adjacent end of the axially extending groove 14 in the embodiment of FIG. 2 is 0.6 times the diameter D of the shank. The axial length B of the web and the axial length L of the groove sections 14a, 14b is the same and is 0.8 times the diameter D of the shank. The maximum depth T of the grooves 14 is 0.2 times the diameter D of the shank 13.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
Claims
We claim:
1. A drill for use in a hand-held drilling device comprises an axially elongated shank arranged to be inserted into the hand-held device, said shank having an axially extending outside circumferential surface with a closed ended axially extending groove formed in the axially extending outside circumferential surface and said groove having ends extending transversely of the axially extending direction thereof, wherein the improvement comprises that said shank has a leading end, a trailing end, and a diameter D, the axially extending distance between the trailing end of said shank and the adjacent end of said axially extending groove is in the range of 0.3 to 1 times the diameter D of said shank, at least one web is located within said axially extending groove extending in the axially extending direction of said groove and also transversely thereof and divides said groove intermediate the ends thereof into axially extending groove sections, the surface of said web is located in the outside circumferential surface of said shank, each said groove section has a base spaced radially inwardly from the outside circumferential surface of said shank with said base extending parallel to the axis of said shank and each said groove section having opposite ends spaced apart in the axial direction with said groove section ends forming shoulders extending transversely of the axial direction.
2. A drill, as set forth in claim 1, wherein the axial length of said web is in the range of 0.4 to 1.1 times the diameter D of said shank, the axial length of each of said axially extending groove sections is in the range of 0.7 to 1.7 times the diameter D of said shank, the maximum depth of said axially extending groove sections is in the range of 0.1 to 0.3 times the diameter D of said shank.
3. A drill, as set forth in claim 1, wherein the axial length of said web is in the range of 0.4 to 1.1 times the diameter D of said shank.
4. A drill, as set forth in claim 1, wherein the axial length of said groove sections of said axially extending groove is in the range of 0.7 to 1.7 times the diameter D of said shank.
5. A drill, as set forth in claim 1, wherein the maximum depth of said axially extending groove inwardly from the outside circumferential surface thereof is in the range of 0.1 to 0.3 times the diameter D of the said shank.
6. A drill, as set forth in claim 1, wherein said axially extending groove sections are V-shaped in cross section transverse of the axial direction.
7. A drill, as set forth in claim 6, wherein the angle enclosed between the sides of said V-shaped axially extending groove sections is in the range of 50.degree. to 130.degree..
8. A drill, as set forth in claim 7, wherein the angle enclosed between the sides of said V-shaped axially extending groove sections is in the range of 50.degree. to 70.degree..
9. A drill, as set forth in claim 2, wherein said axially extending groove sections have a concave surface in section transverse to the axial direction.
10. A drill, as set forth in claim 2, wherein said axially extending groove sections are V-shaped in section transverse to the axial direction.
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