NZ553100A

NZ553100A - Rock drilling head with rinsing channels suitable for both wet and dry drilling

Info

Publication number: NZ553100A
Application number: NZ553100A
Authority: NZ
Inventors: Kay Heemann; Wolfgang Ludwig; Uwe Bohn
Original assignee: Hilti Ag
Priority date: 2006-02-20
Filing date: 2007-02-08
Publication date: 2008-05-30
Also published as: US20070193784A1; DE102006000081A1; AU2007200580A1

Abstract

A rock drilling heat 1 with a drilling diameter D between 25mm and 60mm has at least one rinsing channel 2 formed in the outer surface 3 of the drilling head and expanding from the outer surface 3 inward in the form of a nozzle, the rinsing channel having a diameter S amounting to between 1/20 and 1/5 of the drilling diameter D.

Description

10053200700* ;553100 ;Patent No. 5 Our Ref: 52787NZP00 ;Patents Act 1953 ;COMPLETE SPECIFICATION ;ROCK DRILLING HEAD ;I/We, Hilti Aktiengesellschaft, a body corporate organised under the laws of Liechtenstein of Feldkircherstr. 100, LI-9494 Schaan, LIECHTENSTEIN ;hereby declare the invention, for which l/we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement- ;Total Fee Paid: NZ$250.00 - by Direct Debit (as per covering letter) ;INTELLECTUAL PROPERTY OFFICE OF N.2. ;- 8 FEB 2007 RECEIVED ;501086974_1 .DOC/6858 ;-1 - ;ROCK DRILLING HEAD ;INTELLECTUAL PROPERTY OFFICE ;OF N.2. ;2 8 MAY 2007 ;RECEIVED ;BACKGROUND OF THE INVENTION Field of the Invention ;The present invention relates to a rock drilling head provided with hard material means and having rinsing channels and designed for use, in particular, in blast shot drills or injection self-drilling anchors. ;Description of the Prior Art ;Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. ;Such mass-produced drilling heads have, at a drilling diameter between 25mm and 60mm, a small degree of complexity. So the number of separate parts, such as hard material inserts that form cutters, is limited, for manufacturing reasons, to a small number, maximum five. Dependent on the type of a to-be-drilled rock material, these rock drilling heads are operated in a wet drilling process with low (5 to 30 bar) water pressures or in a dry drilling process with aspiration of drillings (with suction pressure .3 to .7 bar), with the rinsing or suction taking place through the rinsing channels having a rinsing channel diameter between 1/20 and 1/5 of the drilling diameter. ;U.S. Patent No. 4,185,708 discloses such a rock drilling head equipped with hard material cutter means and having cylindrical rinsing channels formed directly of the drilling head base body and having different channel diameters. ;U.S. Patent No. 4,540,056 discloses a rock drilling head equipped with hard material cutter means with a drilling diameter of 2.5cm replaceably secured in head support in which special high pressure nozzles, which are formed as screw-in inserts, are screwed in cylindrical openings. The opening diameter of the high-pressure nozzles is too narrow to ;INTELLECTUAL PROPERTY OFFICE ;OF HZ ;2 8 MAY 2007 ;RECEIVED ;-2- ;provide for removal of drillings at a dry drilling or to obtain, at wet drilling with a low water pressure, a necessary rinsing medium flow. ;It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. ;Advantageously, in one preferred embodiment the present invention provides a rock drilling head equipped with hard material cutter means, having a drilling diameter between 25mm and 60mm, rinsing channels suitable for both wet and dry drilling, and suitable for mass production. ;SUMMARY OF THE INVENTION ;This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a rock drilling head haying a drilling diameter between 25mm and 60mm and including at least one rinsing channel formed in the outer surface of the drilling head and expanding from the outer surface inward in the form of a nozzle, and having a diameter(s) amounting to between 1/20 and 1/5 of the drilling diameter. ;Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". ;With a rinsing channel that constantly expands inwardly in the form of a nozzle (along the flow and having a concave, conical, or convex profile and being, in flow cross-section, rotationally symmetrical, completely symmetrical, and asymmetrical), the drillings, which are aspirated from outside in the rinsing channel in the dry drilling process, cannot be detained there because the cross-section of the rinsing channel constantly widens inward. During wet drilling with low-pressure rinsing means, with the flow directed from the interior outwardly, a high flow velocity is achieved in the narrowing outer region of the ;25 ;INTELLECTUAL PROPERTY OFFICE ;OF N.Z. ;2 8 MAY 2007 ;RECEIVED ;-3- ;rinsing channel, and the drillings, which are accumulated in the rinsing channel, are subjected to the dynamic pressure of the rinsing medium flow and are carried along. ;Advantageously, the rinsing channel expands from the outer surface with a cone angle 5 between 3° and 30°, which ensures a sufficiently large widening of the cross-section inwardly. ;Advantageously, there are provided two rinsing channels which are advantageously arranged symmetrically with respect to the drilling axis, so that with blocking of one of the 10 rinsing channels, at least one other rinsing channel is available. ;Advantageously, the rock drilling head is formed of a base member formed as a casting, with the rinsing channel being advantageously formed during casting. ;15 Advantageously, the rock drilling head is formed of only one base member and only one hard material insert extending diametrically over the drilling diameter and secured in a groove formed in the one base member. This ensures an economical production of the rock drilling head with few process steps. ;20 The novel features of the present invention which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment, when read with reference to the accompanying drawings. ;BRIEF DESCRIPTION OF THE DRAWINGS: ;A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: ;30 ;Fig. 1 is a longitudinal cross-sectional view of a rock drilling head according to the present invention along line I-I in Fig. 2 in three planes; and ;INTELLECTUAL PROPERTY OFFICE ;OF N.Z. ;28 MAY 2007 ;RECEIVED ;-4- ;Fig, 2 is a plan view of the rock drilling head according to the present invention. ;DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT ;A drilling head 1 for a rock drill, which is shown in Figs. 1-2, has drilling diameter D of 35mm and two rinsing channels 2 located on opposite sides of a drilling head axis A. The rinsing channels 2 have a rinsing channel diameter S at an outer surface 3 and equal to about 1/10 of the drilling diameter D. The rinsing channels 2 expand conically inward from the outer surface 3 in form of a nozzle with a cone angle a of 20° that constantly diminishes further inward. The drilling head 1 is formed of exactly two separate parts, a base member 4 of steel cashing and a hard material insert 5 secured in a groove 6 of the base member 4. The hard material insert 5 extends diametrically over the drilling diameter D and forms drilling cutters 7. ;Though the present invention was shown and described with references to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims. *

Claims

-5- INTELLECTUAL PROPERTY OFICE OF NZ 2 8 MAY 2007 RECEIVED THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

1. A rock drilling head having a drilling diameter between 25 mm and 60mm, comprising an outer surface; and at least one rinsing channel formed in the outer surface and expanding from the outer surface inward in form of a nozzle, and having a diameter amounting to between 1/20 and 1/5 of the drilling diameter.

2. A rock drilling head according to claim 1, wherein the rinsing channel expands with a cone angle between 3° and 30°.

3. A rock drilling head according to claim 1 or claim 2, comprising two rinsing channels.

4. A rock drilling head according to claim 3 wherein the two rinsing channels are arranged symmetrically with respect to the drilling axis.

5. A rock drilling head according to any one of the preceding claims, comprising a base member.

6. A rock drilling head according to claim 5, wherein the base member is formed as a steel casting.

7. A rock drilling head according to claim 6 wherein the at least one rinsing channel is formed during casting of the base member.

8. A rock drilling head according to any one of claims 5 to 7, further comprising a hard material insert extending diametrically over the drilling diameter and secured in a groove formed in the base member.

9. A rock drilling head according to claim 8, comprising only one base member, and only one hard material insert extending diametrically over the drilling diameter and secured in a groove formed in the one base member.

10. A rock drilling head according to claim 8 or claim 9 wherein the hard material insert forms at least one drilling cutter.

11. A rock drilling head substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.