Title:
Profiling element
Kind Code:
A1


Abstract:
An element for profiling a wall of a borehole includes a shaft (12; 32) having at least one projecting radially, thread-tapping element (13), and a rotation-transmitting element (15, 35) provided at the first end (14; 34) of the shaft (12); and a cleaning member (21; 41, 46) provided on one of the opposite first (16; 34, 36) and second (34, 36) ends of the shaft a (12; 32).



Inventors:
Ginter, Herbert (Kaufbeuren, DE)
Application Number:
12/218178
Publication Date:
01/15/2009
Filing Date:
07/10/2008
Assignee:
Hilti Aktiengesellschaft
Primary Class:
Other Classes:
175/64
International Classes:
E21B49/00
View Patent Images:
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Primary Examiner:
PAINTER, BRANON C
Attorney, Agent or Firm:
ABELMAN, FRAYNE & SCHWAB (666 THIRD AVENUE, 10TH FLOOR, NEW YORK, NY, 10017, US)
Claims:
What is claimed is:

1. An element for profiling a wall of a borehole, comprising a shaft (12; 32) having opposite first (14; 34) and second (16; 36) ends, at least one projecting radially, thread-tapping element (13), and rotation-transmitting means (15, 35) provided at the first end (14; 34) of the shaft (12; 32); and a cleaning member (21; 41,46) provided on one of the opposite first (16; 34, 36) and second (34, 36) ends of the shaft (12; 32).

2. A profiling element according to claim 1, comprising a further cleaning member (46) provided at another of the first (34, 36) and second (34, 36) ends of the shaft (32).

3. A profiling element according to claim 1, wherein the cleaning member (46) is formed as a radially circumferential element (46).

4. A profiling element according to claim 1, wherein the cleaning member (21; 41) is formed as a disc-shaped element.

5. A profiling element according to claim 1, wherein the cleaning member (21, 41) is formed of a plastic material.

6. A profiling element according to claim 1, wherein the profiling element (46) is formed of metal.

7. A method of chemically setting a fastening element (10) with a profiling element (11) including a shaft (12; 32) having opposite first (14; 34) and second (16; 36) ends, at least one projecting radially thread-tapping element (13), and rotation-transmitting means (15; 35) provided at the first end (14; 34), and a cleaning member (21; 41, 46) provided on one of the opposite first (16; 34, 36) and second (34, 36) ends of the shaft (12; 32), the method comprising the steps of: a. drilling a borehole (4) in a constructional component (6); b. driving the profiling element (11) in the borehole (4); c. filling the borehole (4) with a hardenable mass (9); and d. setting the fastening element (10) in the filed with the hardenable mass (9), borehole (4).

8. A method according to claim 7, wherein the drilling step includes drilling the borehole (4) with a minimal depth (T) corresponding to sum of a predetermined anchoring depth (V) of the fastening element (10) in the hardenable mass (11) and of a length (L) of the profiling element (11).

9. A method according to claim 7, comprising the step of withdrawing the profiling element (11) from the borehole (4) before filling the borehole (4) with the hardenable mass (9).

Description:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an element for profiling a wall of a borehole and including a shaft having opposite first and second ends, at least one projecting radially, thread-tapping element, and rotation-transmitting means provided at the first end. The present invention also relates to a method of setting a chemically anchored fastening element with such a profiling element.

2. Description of the Prior Art

For chemically anchoring a fastening element such as anchor rod, threaded rod, threaded sleeve or reinforcing iron, a borehole is formed in a constructional component in which the fastening element is to be anchored. The borehole is filled with a hardenable mass, e.g., a two-component mortar mass, and the fastening element is set into the filled with the hardenable mass, borehole. After hardening of the filling the borehole, mass, the fastening element has a high load-carrying value.

The force transmission between the fastening element and the constructional component takes place via the hardenable mass. To this end, the fastening element is provided with a profile that insures a good formlocking connection between the fastening element and the hardenable mass.

The connection between the hardenable mass and the constructional component takes place to some extent over formlocking connection resulting from roughness of the borehole wall, and to a substantially greater extent due to adhesion of the hardenable mass to the borehole wall. The adhesion of the hardenable mass to the borehole wall depends first of all from the degree of the wall cleanness and also from moisture in the borehole, e.g., presence of water.

In order to increase of the formlocking connection component, German Patent DE 37 18 158 C2 suggests using a profiling element with a shaft having opposite first and second ends, radially projecting, pin-shaped, cutting tool inserts which form a thread-tapping element, and rotation-transmitting means provided at the first shaft end for receiving a setting tool. During driving of the profiling element in the borehole, a helically shaped continuous undercut is produced in the borehole, whereby the connection component between the hardenable mass and the borehole wall, which is provided by the formlocking connection therebetween, is greatly increased. After formation of the undercut, the profiling element is withdrawn from the borehole.

The drawback of the solution suggested by the above-mentioned German Patent consists in that for a desired adhesion between the hardenable mass and the borehole wall, the borehole should be subsequently cleaned.

In order to clean a borehole before filling it with a hardenable mass, the borehole is blasted with a pump, e.g. This leads to an undesirable dust accumulation outside of the borehole. In order to eliminate this drawback, German Publication DE 197 57 424 A1 suggests using a borehole cleaning device with a hollow shaft with brush elements projecting radially therefrom, with the produced drilling dust aspirated through the hollow shaft. The drawback of this solution consists in that this type of a borehole cleaning requires additional operational steps.

Accordingly, an object of the present invention is to provide a profiling element and a method of setting a chemically anchorable fastening element using the profiling element, which would reduce expenses associated with setting of a chemically anchorable fastening element and would insure both adhesion and formlocking connection of the hardenable mass with the borehole wall.

SUMMARY OF THE INVENTION

This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a profiling element including a cleaning member provided on one of the opposite ends of the shaft of the profiling element.

With the inventive profiling element, the drilling dust, which sticks to the borehole wall, and the drilling dust and drilling which are present in the borehole, are pushed by the cleaning member in the direction of the borehole bottom. In a single operational step, both formation of the undercut in the borehole wall and the cleaning of the borehole are carried out. Advantageously, the profiling element is driven so far in the borehole that the pushed drilling dust and drillings become compressed in the region of the borehole bottom.

According to an advantageous embodiment of the present invention, the cleaning member is provided at a first end of the shaft facing in a direction opposite the drive-in direction of the profiling element, so that drilling dust and drilling, which are additionally, produced during driving of the profiling element in a constructional component, are pushed by the cleaning member in the direction of the borehole bottom.

The profiling element is driven in a borehole, e.g., with electrical or pneumatic power setting tool, with the force transmission from the setting tool to the profiling element being carried out, directly or indirectly, with a setting adapter. The rotation-transmitting means, which are provided at the first shaft end, has advantageously a polygonal shape or is formed as a TORX receptacle for providing an easily releasable torque-transmitting coupling. Preferably, the rotation-transmitting means is provided in a blind bore at the first end of the shaft, so that the profiling element has a short total length. In addition, the setting working tool or the setting adapter can be easily connected with or disconnected from the profiling element when the rotation-transmitting means is provided in a blind bore.

The length of the shaft corresponds to from 0.4 to 0.16 times, preferably, from 0.9 to 1.1 times of the core diameter of the shaft. The core diameter of the shaft corresponds to from 0.9 to 1 times of the nominal diameter of the borehole.

The thread-tapping element, which projects radially from the shaft, is preferably formed as a thread-tapping outer thread formed integrally with the shaft. The outer diameter of the outer thread corresponds preferably to about 1.1-1.3 times of the nominal diameter of the borehole. For an improved tapping action of the outer thread, it is provided with grooves extending transverse to the course of the thread, or separate cutting elements are inserted into the outer thread. Further, the thread can be formed as a multi-start thread, with, advantageously, at least one of the threads having a smaller height than other extending parallel thereto threads.

The profiling element can remain in a borehole and should not transmit any forces after its use. Therefore, it can be heat-treated to obtain an adequate, for its use, hardness of at least 50 HV10 (Hardness test according to Vikers with a test force of 10 kp or 100 N, so that possible dangers such as, e.g., the danger of embrittlement need not be taken into account. Thus, the profiling element can be produced not only simply but also cost-effectively, which is a big advantage in particular, in mass production of which the inventive profiling element is an example.

Preferably, the cleaning member is fixedly secured at the end of the shaft, so that it is held on profiling element without a danger of being lost. Alternatively, the cleaning member can be formed as a separate part which, e.g., is pushed or entrained, in a coupled condition with the profiling element, during driving of the profiling element in the borehole.

Preferably, a set, which consists of at least one inventive profiling element and a setting adapter, is available to the user.

Advantageously, there are provided two cleaning members one of which is provided at the first end of the shaft, and another one is provided at the second opposite end of the shaft. The cleaning member, which is provided at the second, front end of the shaft facing in the setting direction, grazes the drilling dust that sticks to the borehole wall and pushes the drilling dust and drillings, which accumulate in the borehole, toward the borehole bottom. The second cleaning member, which is provided at the rear, in the setting direction, end of the shaft, grazes, upon the profiling element being driven in the borehole, remaining drilling dust from the borehole wall and pushes it, together with the drilling dust and drillings, which are produced during tapping of the undercut by the thread-tapping element, in the direction of the borehole bottom.

Alternatively, the second cleaning member can be loosely secured on the profiling element or is displaced in a loose condition, together with the profiling element, so that the second cleaning member advantageously is removed by the setting working tool or by the setting adapter during withdrawal of the same from the borehole, and one more time cleans the borehole, this time in the direction of the borehole mouth. Thereby, the degree of cleaning of the borehole is additionally increased.

The setting tool and/or the setting adapter can be provided with additional cleaning members, which increase the degree of cleaning the borehole even further.

Advantageously, the cleaning member extends radially circumferentially and projects from the axial projection of the shaft of the profiling element in such a way that during driving of the profiling element, the cleaning member abuts the borehole wall over the entire drive-in length. The cleaning member can be formed, e.g., as a circular ring the outer diameter of which is greater than the nominal diameter of the borehole.

According to an alternative embodiment, the cleaning member is formed as a disc-shaped member with the outer diameter of the cleaning member being greater than the nominal diameter of the borehole. Advantageously, the cleaning member has a disc-shaped form, with the produced thereby, receiving space advantageously facing in the setting direction of the profiling element.

Advantageously, the cleaning member is formed of a plastic material, which insures simple manufacturing and flexible shaping of the cleaning member. E.g., if a cleaning member is formed of a porous foam material, a portion of the produced drilling dust can be received in the pores of the material, so that the necessary size of the receiving space in front of the cleaning member for receiving the produced drilling dust and drillings in the region of the borehole bottom is reduced.

Alternatively, the cleaning member can be formed of metal, e.g., of spring sheet metal, of wire or a wire bundle.

Further, the cleaning member can include a plurality, advantageously, radially projecting brush elements formed of plastics or metal and the extension of which from the shaft surface is greater than the radial distance between the shaft outer surface and the borehole wall.

If the profiling element has more than one cleaning members, they all can be formed of the same or different material. The degree of a borehole cleaning is influenced by selection of the material and shape of the cleaning member.

The method of setting a chemically anchorable fastening element using the inventive profiling element includes, as a first step, drilling of a borehole in a constructional component in which the fastening element is to be anchored. Then, the profiling element is driven into the borehole, whereby the borehole wall is provided with a helically-shaped undercut, and simultaneously, the drilling dust, which sticks to the borehole wall and fills the borehole, and the drillings are pushed by the cleaning member almost completely in front of the profiling element toward the borehole bottom. Thereafter, the borehole is filled with a hardenable mass, and the fastening element is set into the borehole which is filled with the hardenable mass.

If the setting tool or the setting adapter also equipped with at least one cleaning member, then, a portion of the drilling dust and the drillings is removed from the borehole when the setting working tool and/or adapter is pulled from the borehole.

Advantageously, a minimal depth of the borehole corresponds to the sum of a predetermined anchoring depth of the fastening element in the hardenable mass and of a length of the profiling element, so that the profiling element can remain in the borehole and despite that, a sufficient anchoring of the fastening element is insured.

According to a further method step, the profiling element is withdrawn from the borehole before filling the borehole with the hardenable mass. Thereby, a greater anchoring length for the fastening element in the hardenable mass is available even in constructional components having a reduced thickness.

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 embodiments, when read with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS:

The drawings show:

FIG. 1 a side view of a first embodiment of a profiling element according to the present invention;

FIG. 2 a cross-sectional view of a second embodiment of a profiling element according to the present invention with a setting adapter;

FIG. 3a a cross-sectional view illustrating a first step of an inventive method of setting with a profiled element according to the present invention;

FIG. 3b a cross-sectional view illustrating a second step of an inventive method of setting with a profiled element according to the present invention; and

FIG. 3c a cross-sectional view illustrating a third step of an inventive method of setting with a profiled element according to the present invention.

In the drawings, the same parts are designated with the same reference numerals.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A profiling element 11 according to the present invention, a first embodiment of which is shown in FIG. 1, has a shaft 12 with a radially projecting thread-tapping element 13 in form of an outer thread. At a first end 14 of the shaft 12, there is provided a blind bore with a polygonal receptacle, which forms a rotation-transmitting element 15, for receiving a setting tool. At a second end 16 of the shaft 12 opposite the first end 14, there is provided a cleaning member 21 in form of a disc formed of a plastic material. The cleaning member 21 is fixedly secured on the profiling element 11 with fixing means 22.

The cleaning member 21 has a plate-shaped form, with a remote, from the profiling element 11, receptacle.

The length L of the shaft 12 corresponds to 1.0 times of the core diameter K of the shaft 12. The core diameter K of the shaft corresponds to 0.95 times of the nominal diameter D of a borehole 4 (see FIG. 3a) in which the profiling element 11 is set. The outer diameter A of the outer thread corresponds to 1.3 times of the core diameter K of the shaft 12. The outer diameter B of the cleaning member 21 is larger than a nominal diameter D of the borehole 4.

The profiling element 31, which is shown in FIG. 2, has two cleaning members 41 and 46. The first cleaning member 41 is provided at the second 36 of the shaft 12, and the second cleaning member 46 is provided at the first end 34 of the shaft 32. The first cleaning member 41 has likewise a plate-shaped form and is formed of a plastic material. The second cleaning member is formed as a circular ring and is made of metal.

In addition, on the setting tool 26, there can be provided additional brush arrangements 27 which subject the borehole wall to a secondary cleaning. The setting tool 26 is releasably connected with the rotation-transmitting element 35 with its correspondingly formed end 28. The produced connection provides for a simple driving of the profiling element 31 in the borehole 4 with a driving tool and, if necessary, for withdrawal of the profiling element 11 out of the borehole.

The setting tool 26 can be formed as a setting adapter that, if needed, can be arranged between a setting tool without cleaning brush-like elements and the profiling element 31. Such an adapter is shown in FIG. 2 with dash lines.

A method according to the present invention of setting a chemically anchorable fastening element 10 with a profiling element 11 will be explained below with reference to FIGS. 3a-3c. As shown in FIG. 3a, firstly, a borehole 4 with a nominal diameter D is formed in the constructional component 6. The depth T of the borehole 4 corresponds at least to the sum of the necessary anchoring length V of the to-be-anchored fastening element 10 in the hardenable mass 9 and the length L of the profiling element 11. Finally, the profiling element 11 is driven in the borehole 4 with the setting tool 26 by a driving tool not shown, with the cleaning member 21 grazing the borehole wall 5 and pushing the produced drilling dust 7 away in the direction of the bottom of the borehole 4.

Simultaneously, the thread-tapping element 13, which is formed as an outer thread, forms a helically shaped undercut 8 in the borehole wall 5.

As shown in FIG. 3b, the profiling element 11 remains in the borehole 4, with the drilling dust 7 and with drillings, which were pushed previously by the profiling element 11 or the cleaning member 21, accumulating on the bottom of the borehole 4. Then, a corresponding amount of the hardenable mass 9 is brought into the borehole 4.

Finally, as shown in FIG. 3c, a fastening element 10, which is formed as a threaded rod with a profile in form of an outer thread, is set into the borehole 4 filled with the hardenable mass 9, with the hardenable mass 9 rising through the annular space between the fastening element 10 and the tapped borehole wall 5. After hardening of the hardenable mass 9, the force transmission takes place via formlocking connections of the hardenable mass 9 with the fastening element 10 and with the constructional component 6, respectively on one hand, via the profile of the fastening element 10, and on the other hand, via the profile of the borehole wall 5.

In an alternative method step, e.g., when the construction component 6 has a smaller thickness, in order to reduce the necessary borehole depth T, the profiling element 11 can be withdrawn from the borehole 4 before filling it with the hardenable mass 9.

Though the present invention was shown and described with references to the preferred embodiments, such are merely illustrative of the present invention and are 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 embodiments 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.