AU6809100A

AU6809100A - Drilling tool

Info

Publication number: AU6809100A
Application number: AU68091/00A
Authority: AU
Inventors: Josef Bauer; Udo Hauptmann; Martin Richter; Martin Schautt
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 1999-11-11
Filing date: 2000-10-25
Publication date: 2001-05-24
Also published as: JP2001162417A; CN1295898A; DE19954315A1; CA2325061A1

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

4..

.4 .4 4 4, 44e Name of Applicant: Actual Inventors: Address for Service: Invention Title: Hilti Aktiengesellschaft Udo Hauptmann and Martin Richter and Martin Schautt and Josef Bauer BALDWIN SHELSTON WATERS 60 MARGARET STREET SYDNEY NSW 2000 'DRILLING TOOL" The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 29115AUP00 jp A: rlya~ De~~nP~ cived OT ~w~NO" -1A- BACKGROUND OF THE INVENTION The present invention is directed to a drilling tool having an axially extending shaft with a drill head connected to one end. The drill head has a receiving region extending radially outwardly from the diameter of the shaft with at least one cutting plate extending through the receiving region. Two guiding regions mutually opposite one another follow at least in part from the receiving region. Radially outer ends of the guiding regions form guiding surfaces.

000: In DE-195 45 646 a drilling tool is disclosed for working in rock, concrete and S"the like. The drilling tool has a receiving region and two guiding regions located diametrically opposite one another with the both the receiving region and the guiding oregions.extending radially outwardly from the diameter of the shaft. The receiving region and the guiding regions are disposed at an angle to one another. The free ends of the guiding regions facing in the drilling direction, are displaced rearwardly in the drilling direction relative to the end of the receiving region facing in the drilling 15 direction. A cutting plate, formed of a hard metal and extending radially outwardly from the outer contour of the receiving region, is disposed in a recess extending through the receiving region.

A portion of the receiving region, extending parallel to the drilling direction, and the guiding regions, are disposed in one plane and effect a good centering of the drilling tool in a borehole. Guiding elements are formed by the end faces of a pin-shaped guiding element located in a bore hole in the drill head. The end faces have a spherical -2surface for supporting the drilling tool in the bore hole only at a point or, at most, along a line.

An independent, coaxial alignment of the drilling tool relative to the central axis of the borehole cannot be achieved during the drilling operation with the known drilling tool.

SUMMARY OF THE INVENTION ooooo Therefore, the primary object of the present invention is to provide a drilling tool "of the general type affording good centering properties as well as very good guiding properties assuring good quality for the boreholes formed by the drilling tool.

10 In accordance with the present invention, the guiding regions each have a guiding surface extending essentially parallel to the drilling direction and offset in the ooo.

circumferential direction of the drill head by 90 degrees with respect to the receiving *oV region.

S.i With the displacement of the guiding surfaces of the guiding region relative to the receiving region, the coaxial alignment of the drilling tool in a borehole during the drilling operation is insured whereby very good quality results are obtained in the linear character of the borehole.

In addition, a supporting section of the guiding region also contribute to a coaxial alignment of the drilling tool. The supporting section adjoin the guiding surfaces counter to the drilling direction and extend for a portion of the circumferential periphery of the drill head. Particularly good guiding properties of the drilling tool are obtained because the supporting section advantageously extend the circumferential direction of the drill head up to an axial projection surface of the receiving region. The centering of the drilling tool in a borehole and the coaxial alignment of the drilling tool with respect to the central axis of the borehole is gained over a large portion of the circumference of thedrillhead.

Between the receiving region and the guiding regions, drilled material removal grooves are formed for removing drilled material from the borehole. So that the cross ooooo section of the drilled material removal grooves, the extent of which is partially limited go by the supporting sections of the guiding regions extending in the circumferential of the 10 drill heaid, are as large as possible, the end regions of the supporting sections facing in S-the drilling direction taper inwardly.

*oo.

The best possible support of the cutting plate in the receiving region and the very good alignment of the drill head or drilling tool in a borehole is obtained if at least an enveloping circle enclosing the guiding region has a diameter in the range of 0.80 to 0.95 15 times the diameter of an enveloping circle surrounding the cutting plate.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by it use, references should be had to the drawings and description matter in which there are illustrated and described preferred embodiments of the invention.

-4- BRIEF DESCRIPTION OF THE DRAWING Figure 1 is an axially extending side view of a portion of a drilling tool embodying the present invention; Figure 2 is a view similar to Figure 1 with the drilling tool rotated 90 degrees; Figure 3 is a plan view of the drill head of the drilling tool shown in Figure 1; and oooo, S Figure 4 is a perspective view of the drilling tool in Figure 1.

DETAILED DESCRIPTION OF THE INVENTION A drilling tool, as shown in Figs. 1 to 4 has an axially extending shaft 1 with a diameter D1 and has a drill head 2 connected to one end of the shaft. Drill head 2 has a receiving region 3 with a axial length L1 and projects radially beyond the diameter D1 of the shaft on two opposite sides. In addition, the drill head 2 has two opposite guiding Sregions 4 with a length L2. As can be noted in Figs. 1 and 2, an axially extending portion of the receiving region 3 overlaps the leading end region of the guiding regions.

The receiving region 3 and the guiding regions 4 are offset relative to one another in the circumferential direction at an angle of 90 degrees, note Figure 3.

A recess in the receiving region 3 and extending transversely of the drilling direction holds a cutting plate 5 formed of a hard metal with the plate projecting radially outwardly from the receiving region 31. The end of the cutting plate 5 facing in the drilling direction has two cutting edges with concave surfaces, note Fig. 1. The length L3 of the cutting plate 5, extending transversely of the drilling direction decreases opposite to the drilling direction as can be seen in Fig. 1.

The ends of guiding regions 4, facing in the drilling direction, are offset rearwardly relative to the drilling direction with respect to the ends of the receiving region 3, facing in the drilling direction. An enveloping circle 6 around the guiding regions 4 has a diameter D2 which, at most, corresponds to the diameter D3 of an enveloping circle containing the radially outer ends of the cutting plate 5. Each of the guiding regions 4 has a guiding surface 41 extending essentially parallel to the drilling S* •direction, and in the circumferential direction of the drill head, is disposed offset by 10 degrees to the receiving region 3.

The guiding regions 4, extending at least partially parallel to the drilling direction, are located rearwardly relative to the drilling direction with respect to the receiving region 3 which extends parallel to the drilling direction. The amount of offset of the guiding regions 4 with respect to the receiving region 3 corresponds °15 approximately to 0.5 times the length L1 of the receiving region measured parallel to the drilling direction.

At each guiding surface 41 of the guiding regions 4, a supporting section 42 extends in the circumferential direction of the drill head to an axially projecting surface of the receiving region 3 and extends counter to the drilling direction. As can be seen in Fig. 1, the end region of the supporting section 42 tapers counter to the drilling direction.

The parts of the guiding regions 4, in the transition section between the drill head 2 and the shaft 1, extend in the circumferential direction of the drill head and taper -6inwardly towards the shaft axis. The tapering section extends in the circumferential direction of the drill head up to the axially projecting surface of the receiving region 3.

Grooves for the removal of drilled material extend between the receiving region 3 and the guiding regions 4. An enveloping circle, not shown and formed at the base of these grooves, has a diameter corresponding substantially to the diameter D 1 of the shaft 1.

On the opposite sides of the cutting plate 5, note Fig. 3, flushing boreholes 7 are arranged through which a flushing medium, not shown, is supplied for washing the drilled material out of the borehole, not shown, and are located in an end 8 of the drill head faCing in the drilling direction.

oooe *o The enveloping circle 6 including the guiding surfaces 41 of the guiding sections 4, has a diameter D2 corresponding to 0.80 times the length L3 of the cutting plate measured perpendicularly to the drilling direction.

i The drilling tool has a coolant supply duct, not shown; extending parallel to the drilling direction over a part of the tool and is open at an end region of the shaft opposite the drill head 2. The outlets of the two flushing bore holes 7 are connected with the coolant supply duct and are located in the end 8 of the drill head facing in the drilling direction between the receiving region and the guiding regions 4.

What is claimed as new and desired to be protected by letters patent is set forth in the appended claims.

Claims

1. A drilling tool, such as for drilling rock, comprising an axially extending shaft extending in a drilling direction and having a diameter, a drill head connected to and extending axially from one end of said shaft and having a receiving region extending radially outwardly from the diameter of said shaft on two mutually opposite sides, at least one cutting plate secured in said receiving region, two guiding regions mutually opposite one another relative to the axis of said shaft, said guiding regions each having a oo oo first end facing in the drilling direction spaced rearwardly with respect to a first end of said receiving region facing in the drilling direction, radially outer ends of said guiding 10 regions forming guiding surfaces located on an enveloping circle having a diameter at most corresponding to a diameter of an enveloping circle containing radially outer ends of said cutting plate and said guiding surfaces extend essentially parallel to the drilling direction and are offset by 90 degrees with respect to said receiving region. Or 0.:

2. A drilling tool, as set forth in Claim 1, wherein said guiding regions have S.i 15 a supporting section connected with said guiding surface and located opposite to the drilling direction from said receiving region and extending over a circumferential portion on the outer periphery of said drill head.

3. A drilling tool, as set forth in Claim 2, wherein said supporting sections extend in the circumferential direction of the said drill head to an axial projection surface of said receiving region.

4. A drilling tool, as set forth in Claim 2 or 3, wherein an end region of said supporting sections tapers relative to the drilling direction. -8- A drilling tool, as set forth in Claim 1, 2 or 3, wherein the enveloping circle enclosing the guiding regions has a diameter in the range of 0.80 to 0.95 times the diameter of the enveloping circle enclosing the cutting plate.

6. A drilling tool substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings. DATED this 25th day of October 2000 HILTI AKTIENGESELLSCHAFT Attorney: CAROLINE M. BOMMER Fellow Institute of Patent and Trade Mark Attorneys of Australia 10 of BALDWIN SHELSTON WATERS