EP3959055A1

EP3959055A1 - System for securing an anchor in a mineral substrate

Info

Publication number: EP3959055A1
Application number: EP20751112.2A
Authority: EP
Inventors: Andreas Heck; Ulrich Hettich
Original assignee: Ludwig Hettich Holding GmbH and Co KG
Current assignee: Ludwig Hettich Holding GmbH and Co KG
Priority date: 2019-08-08
Filing date: 2020-07-31
Publication date: 2022-03-02
Also published as: ES2941407T3; US20220299059A1; EP3959056A1; EP3959056B1; US20220299060A1; DE102020108589A1; WO2021023652A1; US12025167B2; DE102020108566A1; WO2021023665A1; DK3959056T3; WO2021023664A1; EP3880422A1; US20220297349A1; DE102020108557A1

Abstract

The invention relates to a system for securing an anchor (40) in a borehole in a mineral substrate, in particular concrete, mortar, or brickwork, comprising an anchor (40) with a core section and a threaded section and comprising a furrowing tool for furrowing an internal thread in the borehole, said furrowing tool comprising the following: a main part with a leading end and a trailing end, wherein a force is applied via which a torque can be transmitted to the main part in order to rotate the furrowing tool into the borehole and furrow the thread, and the main part has an outer surface equipped with a furrowing thread which is suitable for furrowing the internal thread into the wall of the borehole. The ratio of the length h_eff of the threaded section of the anchor to the nominal diameter d_b of the borehole satisfies the following: h_eff/d_b ≥ 10.0, preferably ≥ 12.0, particularly preferably ≥ 15.0, and in particular ≥ 30.0.

Description

System for fastening an anchor in a mineral substrate

FIELD OF THE INVENTION

The present invention is in the field of anchoring technology. In particular, it concerns a system and a method for fastening an anchor in a mineral substrate.

BACKGROUND OF THE TECHNOLOGY

Anchoring in mineral subsoil, for example concrete or masonry, has the task of transferring loads from an attachment into the anchoring base or, in the sense of reinforcement, absorbing tensile loads within a component structure. The prerequisite for this is that this anchoring can subsequently be incorporated into the structure or the anchoring base in the sense of its use.

Screw anchors are known from the prior art, which have a self-tapping thread or self-tapping thread, with the help of which, when the screw anchor is screwed in, an internal thread is grooved into a borehole in the mineral substrate.

Alternatively, it has been proposed to form an internal thread in the borehole before screwing in the screw anchor with the aid of a specially provided forming tool. Such a tool is disclosed, for example, in EP 0 625 400 Ai. In DE 19735 280 Ai and DE 199 05 845 Ai, a screw fastening set is known which comprises a thread cutter designed in the manner of a screw and a screw made of corrosion-resistant material.

According to EAD 330232-00-0601 for screw anchors in concrete, the effective anchorage depth must not exceed eight times the nominal diameter d _{b of} the drill hole. Accordingly, known screw anchors for use in concrete also have threaded sections whose length is eight times the nominal diameter d _{b of} the borehole, or at most only slightly exceeds ge.

Furthermore, in the prior art, especially in the case of subsequent reinforcement or the formation of overlapping joints, such as those required for connecting reinforcement, for example required, appropriate anchor rods in a complex adhesive or composite process are attached to the mineral substrate. The steps required for this are:

- Making the borehole

- laborious cleaning of the borehole with multiple flushing and blowing out, - dosed filling with mortar or compound,

- Insertion of the anchor rod, and

- Hardening of the composite mass over several hours.

SUMMARY OF THE INVENTION

The invention is based on the object of specifying a method and a system for fastening an anchor in a mineral subsurface, which allows easy and secure placement, but at the same time enables a reliably high load level. This object is achieved by a system according to claim 1, a method according to claim 26, a grooving tool according to claim 44 and an anchor according to claim 44. Advantageous further developments are given in the dependent claims.

A first aspect of the invention relates to a system for fastening an anchor in a borehole in a mineral subsurface, in particular concrete, mortar or masonry, which system comprises an anchor with a core section and a threaded section, the core section having a core diameter di and the threaded section having an outside diameter d _G has. The anchor can be, for example, a monolithic screw known per se with a concrete screw thread, and in this case the “core section” would be formed by the core and the “threaded section” by the thread of this monolithic screw. However, the invention is not limited to such anchors. For example, the anchor can be formed by a threaded sleeve with an external thread that is hollow on the inside and therefore does not have a “core” in the strictest sense of the word. For the purposes of the present disclosure, however, it has a “core section” which in this case corresponds to a section between two adjacent threads. Furthermore, an anchor within the scope of the invention can also be designed in two parts, and for example comprise a helix with a thread ridge into which a Ge threaded rod is screwed in the assembled state of the anchor, which is also part of the two-part anchor. In this case, the “threaded section” of the anchor is formed by the thread ridge of the helix of the two-part anchor, as will be explained in more detail below with reference to an exemplary embodiment.

The system further includes a forming tool for forming internal threads in the borehole. The grooving tool comprises an at least approximately cylindrical one or conical base body with a leading and a trailing end, wherein - typically (but not necessarily) at the trailing end - a force application is attached or attachable via which a torque for screwing the grooving tool into the borehole and for grooving the thread on the Base body is portable over. In this case, the base body has an outer surface on which a furrow thread is ausgebil det, which is suitable for furrowing the internal thread into the wall of the borehole.

Furthermore, the following applies to the ratio of the length h _{eff of} the threaded section of the anchor and the nominal diameter d _{b of} the borehole: h _eff / d _b > lo.o, preferably> 12.0, particularly preferably> 15.0, and in particular> 30, 0. The “length of the thread section” refers to the axial length of the part of the armature in which the threads are provided.

Note that the term “heff” is primarily used in the present disclosure to denote the length of the threaded portion of the anchor. When describing fastening methods, however, the size h _e ff is also used to denote the anchorage depth of the anchor when it is used. The person skilled in the art understands that the effective anchoring depth can correspond at most to the length of the threaded section of the anchor, but can also be smaller depending on the substrate or use. From the respective context, however, it is always clear whether it is the length of the threaded section of the anchor itself or its anchoring depth in use.

Please note that according to EAD 330232-00-0601, the effective anchorage depth for screw anchors in concrete must not exceed eight times the nominal diameter d _{b of} the drill hole. Accordingly, known screw anchors for use in concrete also have threaded sections whose length does not exceed eight times the nominal diameter d _{b of} the borehole, or at most only slightly exceeds it. Deviating from this, one aspect of the invention provides systems in which the length of the threaded section is significantly greater than the nominal diameter of the borehole. Note that this applies to both one-piece and two-piece anchors. Such exceptionally long anchors can be used in particular for the purpose of subsequent reinforcement of the mineral fastening base, especially concrete, for connecting a concrete part to an existing concrete structure or for forming overlapping joints.

As mentioned at the beginning, according to the prior art, especially in the case of subsequent reinforcement or in the formation of overlapping joints, such as are required, for example, for connection reinforcement, vent-corresponding anchor rods in a complex Bonding or bonding process attached to the mineral substrate. The steps required for this are:

- Making the borehole

- Insertion of the anchor rod, and

- Hardening of the composite mass over several hours.

The critical factor is the creation of a secure connection between the anchor rod and the anchorage base. The quality of the bond depends on the purity of the surfaces, the temperature and a bond that is as bubble-free as possible. Because this procedure is prone to errors, it may only be carried out by trained, certified persons whose proof of suitability must be regularly checked and proven. This method is therefore currently very complex and expensive.

With a system according to the invention, on the other hand, a subsequent reinforcement or an overlap joint can be implemented simply, quickly, reliably and with a significantly lower risk of error than in the prior art, without the need for special specialist personnel. A particular factor here is that practically any anchor lengths can be used by using the grooving tool, because threads of practically any length can be grooved, and the screwing force can be kept sufficiently low even in the case of long lengths by forming the internal thread beforehand. In some embodiments, the anchor is formed by a screw in which the ge-named threaded section is connected to the named core section in a non-positive, material or form-fitting manner. Since the thread of the screw does not have to be formed for grooving in the anchoring base, there are great freedoms in terms of material and manufacturing process that can be exploited in terms of manufacturing costs and / or the respective requirements for the screw in the planned use. In preferred embodiments, the screw consists, for example, at least predominantly of corrosion-resistant steel, the hardness of which would not be sufficient for independent grooving of a thread in a mineral subsurface, of non-ferrous metal, in particular aluminum, or of plastic, which can be fiber-reinforced in certain embodiments.

In an alternative embodiment, the anchor is formed by a threaded sleeve which has an external thread which forms the said threaded section. The threaded sleeve can also have an internal thread, in particular a metric internal thread. point. In particularly preferred embodiments, the threaded sleeve is wound from a profile tape that has a radially inner and a radially outer side, with a thread ridge being formed on the radially outer side which is suitable for screwing into the internal thread formed in the borehole with the aid of the forming tool become. Such wound threaded sleeves can be manufactured very inexpensively, but it is technically not easy to design such wound threaded sleeves so that they can form their own thread in a mineral substrate. One difficulty is the sufficient hardness at least in the grooving part of the thread, another difficulty is the limited torsional strength of a wound sleeve, which makes it difficult to obtain the torques required for screwing in and simultaneous thread forming from the trailing end, where the force is usually applied would be to transfer to the leading end where the furrow work is done. In view of these difficulties, special modifications of a wound threaded sleeve have been proposed, which are described, for example, in DE io 2013 09987 Ai and EP 3 219442 Ai. The above-mentioned requirements for the threaded sleeve do not occur, or at least to a much lesser extent, if they are used in a system according to the invention in combination with the grooving tool. Also for the threaded sleeve, within the framework of the system according to the invention, the stated degrees of freedom with regard to the materials to be used, among which corrosion-resistant steel, non-ferrous metal, in particular aluminum, or plastic, in particular fiber-reinforced plastic, are also given. Note that the threaded sleeve is also to be understood as an “anchor” within the meaning of the invention. The “core section” is formed by the outer sleeve wall between the threads. In a particularly preferred embodiment, the anchor is formed in at least two parts and comprises, on the one hand, a helix that can be screwed into the internal thread in the borehole formed with the aid of the forming tool. The helix is preferably formed by a wound profile strip which has a radially inner and a radially outer side, with a thread ridge being formed on the radially outer side which is suitable for being screwed into the internal thread formed with the aid of the forming tool in the borehole. Furthermore, the two-part anchor comprises a screw or threaded rod with an external thread that is suitable for being screwed into the helix. The threaded rod can in particular be formed by a formwork tie rod, as is commercially available, for example, from BETOmax, and which can have a B15 or a B20 thread, for example.

The screw or threaded rod preferably has a thread that is rectangular or trapezoidal in cross section, with a flattened thread tip, which in this case is the called core section of the two-part anchor, or at least a part of the Kernab section forms.

This two-part design of the anchor has a number of technical advantages. On the one hand, they can be produced very inexpensively, which is particularly important for long lengths. This applies in particular to variants in which a threaded rod of the type of the aforementioned formwork tie rod is used, which is very cost-effective and is in any case available in virtually any length in concrete construction. By combining them with the helix and the grooving tool, these inexpensive threaded rods, which are known per se, can be firmly and easily anchored in the anchoring base, and can be used in particular for subsequent reinforcement, for connecting a concrete part to an existing concrete structure or for forming overlapping joints.

Two-part anchors offer advantages, especially for very long lengths, because the screwing-in forces are limited in each individual step (i.e. inserting the helix, screwing in the screw / threaded rod), because suitable threaded rods are available inexpensively in all required lengths, and because the helix is also can be produced comparatively simply and inexpensively in the required lengths, virtually "by the meter". In contrast to this, the production of conventional screw anchors, which are usually rolled and the heads of which are formed by forming, cannot easily be transferred to very long lengths.

Another advantage of the two-part anchor is that it offers the possibility of re-expansion if there are cracks in the anchoring base, especially concrete. For this purpose, it is advantageous if the external thread of the screw or threaded rod has at least one inclined thread flank which is suitable for pulling the helix in the event of tensile loads (i.e. load in one direction out of the borehole) and / or pressure loads (i.e. load in the direction of in spread open radially into the wellbore), the example forms at least one inclined flank with the radial direction an angle of at least 30 ° preference, of at least 45 ^0th The static friction between the screw or threaded rod and the helix should be sufficiently small that the helix always remains in contact with the anchoring substrate even when cracks form in the anchoring substrate, i.e. it follows this through spreading when cracks form, which requires that static friction between the anchoring base and the helix exceeds the effective static friction between the helix and the screw / threaded rod.

In an advantageous embodiment, there is therefore a coefficient of static friction Lin between the at least one thread flank and the section of the helix that is used in the case of said thread flank Tensile or compressive load can slide along the thread flank, in a range of 0.05 nm _{H <} 0.50, with more preferably: 0.075 ^ Lin, preferably 0.125 <m _H and / or m _{H <} 0.25, preferably m _{H <0.20} .

In alternative embodiments, an additional intermediate helix can also be provided, which is arranged between the screw and the aforementioned helix (that is, between the screw and the helix that is to be screwed into the internal thread grooved with the aid of the grooving tool). The flank of the intermediate helix then has the function of the above-mentioned thread flank when the helix is spread apart. The intermediate helix makes a thread of the screw of the threaded rod specially shaped for spreading unnecessary. In particular, it can be combined with cheaply available screws or threaded rods, for example formwork tie rods, whereby the costs for the system as a whole can be reduced.

Preferably, an inclined thread flank, an inclined flank of the intermediate helix and / or a section of the helix which slides along the inclined thread flank under load when spreading has a coating that reduces the sliding resistance. Such coatings can be applied by means of chemical or electrochemical processes, as painting or by thermal spraying.

Preferably, a plurality of elevations are formed on the outer surface of the base body of the forming tool, each having a cutting edge, with all cutting edges at least partially resting on an imaginary cylinder with a diameter (d ₀ ), and with the cutting edges being suitable for screwing in the Furch tool in the borehole to at least partially remove the inner wall of the borehole in order to adapt the inner wall of the borehole to the imaginary cylinder.

WO 2017/025318A1 discloses a method for setting a screw in a substrate made of a mineral building material. An internal thread is created in the borehole by means of a tap provided with a cutting thread, and the screw is then introduced into the borehole, the external thread of the screw being screwed into the thread produced by the tap in the borehole. According to this document, the outer diameter of the cutting thread of the tap should be smaller than the outer diameter of the outer thread of the associated screw. In other words, it is proposed that the cutting thread of the screw tap be dimensioned so that the internal thread cut in front of the external thread of the screw is smaller. Due to this shortage, the thread tip of the external thread of the screw cuts into the screw when the screw is screwed in, despite the pre-formed internal thread Substrate, so that when the screw is screwed in, loose substrate particles are specifically produced which, according to the teaching of this document, are intended to ensure the desired compression of the screw with the surrounding borehole wall in order to stabilize the borehole. According to this document, it is preferred if the outer diameter of the cutting thread of the tap is only 0.85 times to 0.92 times the outer diameter of the external thread of the screw. As a result, when the screw is screwed in, a certain screwing resistance is generated at the thread tip, which is described as a “solid setting feeling”. Deviating from the teaching of WO 2017/025318, the inventors' investigations suggest that a significant increase in load is only possible by stabilizing the concrete bracket at the thread base of the screw anchor. This was confirmed by the inventors' load level critical tests, especially in cracked concrete. Under load, high pressures occur under the thread flanks of the screw anchor, which lead to a kind of “plasticization” of the concrete matrix, during which pores are displaced and the concrete matrix is irreversibly deformed. Breaking out of the bracket can be prevented if the anchor creates a sufficient supporting effect, which helps to withstand the high pressures of the local load application. For this reason, the gap between the core of the anchor and the borehole wall should be as small as possible over the entire bond.

As a rule, drill holes in concrete are made with a double-edged hammer drill. A hammer stroke is superimposed with a rotary movement in such a way that in the working stroke the chisel is driven into the anchoring base without rotation and the return stroke is superimposed with a rotary movement. This process creates boreholes that are not cylindrical, but rather have a kind of "helix shape". The cross-section of the drill hole typically takes the form of a so-called constant thickness, with a number of sides that exceeds the number of cutting edges of the drill by one. In the typical case of a drill with two cutting edges, the special case is a cross section in the form of a so-called Releaux triangle. As a result, although the core rests against the borehole wall in many places, so that the screw core appears to sit tightly in the borehole and, when screwing in, significant frictional forces also occur between sections of the core and sections of the non-cylindrical borehole (which is a simple enlargement of the Would prohibit core diameter of the anchor), the volume of the gap between see the core of the anchor and the borehole wall is larger than would be required for an optimal le support effect. Preferred embodiments of the invention therefore provide a system with a special forming tool which has an at least approximately cylindrical or conical base body with an outer surface on which a forming thread is formed which is suitable for forming the internal thread into the wall of the borehole. A plurality of elevations are also formed on the outer surface of the base body, each having a cutting edge, with all cutting edges at least partially lying on an imaginary cylinder with a diameter d ₀ , and with the cutting edges being suitable when the forming tool is screwed into the borehole the inner wall of the borehole to be removed at least partially in order to adapt the inner wall of the borehole to the imaginary Zy cylinder. As a result, the borehole is typically not only homogenized in its shape, but also smoothed. This makes it possible to use anchors with a larger core diameter than without such machining of the inner wall of the borehole with the aid of the grooving tool, without significantly increasing the screwing forces due to the friction of the core on the borehole wall. As a result, the total volume between the core of the anchor and the borehole wall can be reduced, whereby the support effect can be increased.

The reference that the cutting edges are “at least in sections” on the imaginary cylinder includes the possibility that the cutting edges actually lie on the imaginary cylinder over their entire length. However, this is not necessary for the function of removing the inner wall of the borehole in order to adapt it to the imaginary cylinder. For this it is sufficient if the cutting edges lie at least over part of their length, in extreme cases only at one point on this cylinder. For example, the cutting edges could only be in a rear in the screw-in direction, i. H. trailing section lie on the lateral surface of the imaginary cylinder, but taper conically in a leading section in the screwing direction to facilitate screwing. In this leading section, the cutting edges could, for example, lie on the lateral surface of a truncated cone which tapers conically in the screwing direction of the forming tool and whose base surface has the same diameter as the imaginary cylinder. It is even conceivable, although not preferred, for the cutting edges to lie over their entire length on a truncated cone, the surface lines of which are only slightly inclined with respect to the central axis; In this case, only the trailing end of the cutting edge would then lie on the lateral surface of the imaginary cylinder, corresponding to the above-mentioned extreme case that they are "only at one point" on the imaginary cylinder.

In an advantageous embodiment, the cutting edge is formed by an edge to which a substantially radial surface facing the radial direction by less than 30 °, preferably less than 15 ⁰ inclined, and a substantially tangential surface opposite to the radial direction to at least 45 ⁰ , butt against each other, where shows the surface normal of the essentially radial surface in the screwing direction. In this case, the “screwing direction” means the direction of rotation when screwing in, ie a tangential direction, not the axial advance direction that results when screwing in. The “essentially radial surface” is at least roughly speaking perpendicular to the borehole wall, while the “essentially tangential surface” is a surface that is at least more parallel than perpendicular to the borehole wall. This shape can provide a stable, sufficiently sharp and low-wear cutting edge.

In an advantageous embodiment, the grooving tool has at least four, preferably at least six, of the named elevations with an associated cutting edge. Such a large number of elevations helps to provide an almost cylindrical shape of the drill hole inner wall. An embodiment with only two or three cutting edges is possible, but in practice leads to a less good shape of the machined borehole and also to increased wear on each individual cutting edge. Similar to the drill, a cross-sectional shape can also result here that at least resembles a constant thickness and approaches a circle with an increasing number of elevations, so that the shape of the treated borehole becomes more similar to a cylinder shape with a greater number of elevations. In a preferred embodiment, the armature is manufactured with a manufacturing tolerance of less than 0.2 * (d _t ,) ⁰ _' ³ mm with respect to the core diameter di, the Furchwerk tool is manufactured with a manufacturing tolerance of less with respect to the diameter d ₀ as 0.1 · (d _b ) ⁰ _' ³ mm, and the following applies: 0.0 mm <d ₀ - the <0.7 mm, preferably 0.1 mm <d ₀ - the <0.5 mm.

The nominal diameter d _{b of} the borehole corresponds to the size specification of a drill, to which the anchor is adapted, in millimeters, but is itself dimensionless. If, for example, the anchor is intended for use with an 8 mm drill, then d _b = 8. The manufacturing tolerances are scaled here with the 0.3th power of the nominal diameter d _b . This dimensioning results in a very small volume between the core of the anchor and the borehole wall, which in practice offers high load capacities, but at the same time avoids excessive screwing-in torques due to friction between the inner wall of the borehole and the core of the anchor.

In an advantageous embodiment, the armature is manufactured with a manufacturing tolerance of less than 0.2 · (d _b ) ⁰³ mm in relation to the outer diameter d _{G of} its thread the grooving tool is also manufactured with a manufacturing tolerance of less than 0.2 (d _b ) ⁰ _' ³ mm in relation to the maximum outside diameter d _{F of} its grooving thread, and the following applies:

0.0 <(d _F - do) / di <0.15, preferably 0.025 <(d _F - de) / die <0.10

The reference to the “maximum outer diameter d _{F of} the threading thread” takes into account the fact that the threading thread typically has a variable outer diameter in order to form a gate. For the depth of the ultimately grooved internal thread, however, only the maximum external diameter d _{F is} decisive. The same applies to the thread of the anchor, which can also have an increasing thread diameter at its leading end, but the outer diameter of the Ge thread of the anchor is usually constant over most of the length of the anchor. The outer diameter d _G here means the diameter of the smallest imaginary cylinder into which the anchor thread can be inscribed as a whole.

Deviating from the teaching of WO 2017/025318, this embodiment of the invention does not provide for the outer diameter d _{G of} the thread of the anchor to be selected to be greater than the maximum outer diameter d _{F of} the grooving thread. While WO 2017/025318 proposes a smaller size of the pre-cut internal thread compared to the external thread of the anchor in order to artificially remove substrate particles and to increase the screwing torque for the purpose of a “solid setting feeling”, one aspect of the present disclosure aims at machining the borehole in this way that the drill hole itself is as close as possible to the core everywhere. A limiting factor for the anchor diameter, in spite of the machining of the borehole to approximate an ideal cylindrical shape, is friction between the core and the borehole wall and an associated increase in the insertion torque. The preferred embodiment of the invention therefore avoids the additional screw-in resistance, as is deliberately created in WO 2017/025318 by deformation work at the tip of the anchor thread, in favor of the possibility of choosing a larger core diameter of the anchor. One could assume that an increase in the load can also be achieved by a particularly close contact of the thread tip of the anchor on the anchoring base, or even a bracing of the thread tip. According to the inventors' knowledge, this is not the case in practice. According to the findings of the inventor, the load-limiting mechanism in a screw anchor is the behavior of the anchor under load in an opening or closing crack. If the crack opens, the thread tip is exposed anyway, so that the hoped-for mechanism does not come into play in this case. In an advantageous embodiment, the self-tapping thread has a plurality of turns, and the plurality of elevations is arranged between turns of the self-tapping thread. This leads to an optimal guidance of the cutting edges in the borehole on the lateral surface of the imaginary cylinder and thus to an improved configuration of the machined borehole.

The self-tapping thread preferably has fewer than four turns, particularly preferably between 2.8 and 3.8 turns. In this way, the force required to screw in the grooving tool can be kept sufficiently small, even if the wall of the drill hole is partially removed or ground smooth with the aid of the cutting edges when screwing in the grooving tool.

In an advantageous embodiment, the forming tool, preferably on the side of the forming thread closer to the trailing end, has an annular scraping element which is suitable for scraping off drill dust from the borehole wall. In this way, the drill hole treated with the aid of the grooving tool is largely cleaned of drill dust and debris from the cutting edges. According to this embodiment, deviating from the above-mentioned WO 2017/025318, it is therefore not intended that significant amounts of substrate particles remain in the borehole between the anchor and the borehole wall. Rather, the not yet deformed concrete matrix should be supported essentially directly by the core of the anchor or the thread base, which due to the processing of the borehole with the aid of the grooving tool can be closer to the concrete matrix not yet deformed under load than in the prior art. Preferably, the outside diameter of the threading thread decreases in the direction of the leading de end in order to facilitate the screwing in of the threading tool.

Preferably, recesses are formed in the thread and incisors, in particular wedge-shaped incisors, are formed between adjacent recesses, at least some of the recesses preferably corresponding to the entire height of the thread so that the thread is interrupted in sections.

The forming tool, or at least its forming thread, preferably has a Rockwell hardness of at least 55 HRC, preferably of at least 60 HRC. The forming tool, or at least the forming thread, can consist of an alloyed steel, tool steel, stellite, a ceramic material or a hard metal. In preferred embodiments, the furrowing tool is intended for multiple uses. This is where the grooving tool differs from some of the grooving tools known in the prior art, for example the thread cutter from DE 199 05 845 A1, which is explicitly only intended for single use.

In an advantageous embodiment, the grooving tool has a drive element at its leading end which is suitable for interacting with a force application of the anchor or - in the case of multi-part anchors described below - a part of the same to screw into the drill hole treated with the grooving tool is. This facilitates the process of setting the anchor, which - like the grooving tool - is typically screwed in with the aid of an electric drill because the tool does not have to be changed between thread cutting and screwing in the anchor. The drive element at the leading end of the furrowing tool can in particular be a polygonal or six-round drive that can be brought into engagement with a corresponding drive element or force application on the armature. However, the disclosure is not limited to such drive elements; rather, they can vary depending on the type of armature. As will be explained in more detail below, the armature can be formed, for example, by a threaded sleeve, at the trailing end of which, for example, a groove can be provided as a force application or drive element; in this case the drive element at the leading end of the furrowing tool would be a corresponding element which can engage in this groove.

In some applications it can be advantageous if the anchor or at least a part of it is completely inserted into the mineral subsoil, and in particular sunk into the borehole, so that its trailing end is spaced from the surface of the subsoil. This applies, for example, to applications in which the anchor is formed by a threaded sleeve, by a threaded rod that, unlike a screw with a head, can be completely received in the borehole, or by an at least two-part anchor, described in more detail below, in which a helix is part of the at least two-part anchor is to be screwed completely into the drill hole.

For such purposes it can be provided that the drive element of the furrowing tool and the force application of the armature are coordinated so that they can assume an engagement position, and in this engagement position the relative orientation of the furrowing tool and the armature or said part thereof is determined in this way that the thread is an imaginary continuation of the thread of the anchor, When the furrowing tool is rotated in the screwing-in direction, a torque can be transmitted from its drive element to the force application of the armature or part of the same, and when the furrowing tool is turned against the screwing-in direction, no torque is applied from its drive element to the force application of the armature or part of the same ben is transferable.

Because the grooving tool and the anchor are aligned in relation to one another in the mentioned engagement position that the grooving thread lies on the imaginary continuation of the anchor thread, the grooving tool can be screwed into the borehole again when the anchor or anchor part is countersunk to furrow another thread, because the furrow thread is automatically guided into the already existing furrowed thread in the borehole due to the synchronization with the anchor thread. As long as the grooving tool is rotated in the screwing-in direction, it transmits a torque from its drive element to the force applied by the anchor / anchor part, so that it is screwed into the thread grooved in the borehole. When the anchor or part of the same has reached the desired depth of use, the direction of rotation of the Furchwerk is reversed so that it is screwed out of the borehole. In this reverse direction of rotation, no torque is exerted on the force application of the armature / armature part, so that the armature / armature part remains in the recessed position.

Various configurations of the drive element of the grooving tool and the force application of the armature / armature part are possible which offer this functionality, and this aspect of the invention is not limited to a specific configuration. EMBODIMENTS In preferred, the driving element of the thread-forming tool a first abutment surface, the surface normal N with a tangent vector t a maximum angle of 45 ^0, is preferably maximally 30 ° and particularly preferably a maximum of 15 ^0, wherein the Tan defined gentialvektor t as a vector product of an axial vector a, which is directed towards the leading end of the furrowing tool, and a radial vector r, the tip of which lies on the first stop surface, so that: t = axr, and the force application of the anchor / anchor part has a first stop surface which rests against the first stop surface of the drive element when the drive element and the force application assume the engagement position.

The tangential vector t is clearly speaking a vector which indicates at any time in which direction the first stop surface is moving due to the rotation of the forming tool in the screwing-in direction. An axial movement due to the thread pitch is superimposed on this rotation, but this is not taken into account by the tangential vector t becomes. In the present preferred embodiment, this direction is to at least on approaching with the surface normal n the first abutment surface coincide, forming n with the surface normal that is a maximum angle of 45 ^0, preferably at most 30 °, and particularly preferably ma ximal 15 ⁰ to when screwing in the thread-forming tool effectively to be able to transmit a torque via the first stop surfaces to the force application of the armature / armature part. Furthermore, the first stop surfaces help to define the relative alignment of the furrowing tool and the anchor / anchor part with respect to their rotational position when the first stop surfaces abut against each other in the said engagement position, thereby synchronizing the anchor thread and the furrow thread with respect to ensure their rotational position. When the furrowing tool is unscrewed, however, the first stop surfaces simply lift from each other so that no torque is transmitted from the furrowing tool to the force applied by the anchor / anchor part, and the anchor / anchor part can remain in the ground while the furrowing tool is unscrewed.

In an advantageous development, the drive element of the grooving tool has a second stop surface, the surface normal of which has a component in the direction of the axial vector a, and the power drive of the armature / armature part has a second stop surface that rests on the second stop surface of the drive element when the Drive element and the power drive take the engagement position. The second stop surfaces help to define the relative orientations of the grooving tool and the anchor / anchor part in relation to their axial position when the second stop surfaces abut one another in the mentioned engagement position, thereby synchronizing the anchor thread and the grooving thread with respect to their axial position to ensure.

In an advantageous development, the drive element has an axial projection and the force application of the armature has a receptacle for receiving the axial projection when the drive element and the power drive assume the engagement position. Through the combination of the axial projection and the receptacle, a secure engagement between the drive element of the furrowing tool and the force application of the armature / armature part can be established.

The anchor is preferably formed by a threaded sleeve or the part of the anchor is formed by a helix, and the receptacle for receiving the axial projection is formed by the interior of the threaded sleeve or the helix. WO 2021/023665 - 16 - PCT / EP2020 / 071691

In a second aspect, the present invention relates to a method for fastening an anchor with a core section and a threaded section in a borehole in a mineral subsoil, with the following steps:

Drilling a borehole,

Forming an internal thread in the borehole by screwing a forming tool into the borehole, and

Insertion of the anchor into the borehole, the furrowing tool comprising: an at least approximately cylindrical or conical base body with a leading and a trailing end, with a force application being provided via which a torque for turning the furrowing tool into the borehole and for furrowing the Thread is transferred to the base body, wherein the base body has an outer surface on which a self-tapping thread is formed which is suitable for tapping the internal thread into the wall of the borehole. The anchor is inserted into the borehole with an effective anchoring depth h _eff , whereby the following applies to the ratio of the effective anchoring depth h _eff and the nominal diameter d _{b of} the borehole: h _eff / d _b > lo.o, preferably> 12.0, particularly preferably> 15.0, and in particular> 30.0.

The anchor is preferably formed by a screw or threaded rod, in which the said threaded section is non-positively, materially or positively connected to the said Kernab section, the screw or threaded rod preferably at least predominantly made of corrosion-resistant steel, non-ferrous metal, in particular aluminum or plastic , in particular fiber-reinforced plastic.

In an advantageous embodiment of the method, the anchor is formed by a threaded sleeve which has an external thread that forms the said threaded section, the threaded sleeve preferably having an internal thread, in particular a metric internal thread, and / or the threaded sleeve preferably being made from a profile band is wound, which has a radially inner and a radially outer side, wherein a thread ridge is formed on the radially äu ßeren side, which is suitable to be screwed into the grooved with the aid of the Furchwerk internal thread in the borehole, and / or wherein the threaded sleeve at least predominantly made of corrosion-resistant steel, non-ferrous metal, in particular special aluminum or plastic, in particular fiber-reinforced plastic. In an advantageous embodiment of the method, the anchor is designed in at least two parts, the at least two-part anchor comprising the following: a helix which can be screwed into the internal thread in the borehole formed with the aid of the grooving tool, the helix preferably being formed by a wound profile strip that has a has a radially inner and a radially outer side, wherein a thread ridge is formed on the radially outer side, which is suitable to be screwed into the grooved internal thread in the borehole with the aid of the grooving tool, and a screw or threaded rod with an external thread that can be screwed into the helix, the threaded rod being formed in particular by a formwork tie rod. In addition or alternatively, the screw or threaded rod preferably has a thread with a rectangular or trapezoidal cross section, with a flattened thread tip which forms the aforementioned core section of the two-part anchor. The mentioned insertion of the anchor into the borehole comprises the following:

Screwing the helix into the internal thread in the borehole that has been grooved with the aid of the grooving tool, and

Screwing the screw or threaded rod into the helix.

In an advantageous embodiment of the method, the external thread of the screw or threaded rod, or an additionally provided intermediate helix arranged between the screw or threaded rod and the helix, has at least one inclined flank which is suitable for pulling the helix out of the borehole in one direction under tensile loads and / or in radially spread open when pressure loads in the direction of the wellbore, wherein the at least one inclined edge with the radial direction forms an angle of Minim least 30 °, preferably of at least 45 ^0th

Additionally or alternatively, there is a coefficient of static friction pn between the at least one inclined flank of the screw or threaded rod or intermediate helix and the section of the helix that can slide along the inclined flank under the tensile or compressive load mentioned, in a range of 0.05 <P _{H <0.50} , more preferably: 0.075 ^ P _H , preferably 0.125 <p _H and / or p _{H <} 0.25, preferably P _H <0.20.

Additionally or alternatively, the at least one inclined thread flank, the inclined flank of the intermediate helix and / or a section of the helix which slides along the inclined flank when spreading under load has a coating which reduces the sliding resistance. WO 2021/023665-18-PCT / EP2020 / 071691

A plurality of elevations, each having a cutting edge, are preferably formed on the outer surface of the base body of the forming tool, all cutting edges at least in sections lying on an imaginary cylinder with a diameter d ₀ . Furthermore, when the Furchwerk is screwed into the borehole, the inner wall of the borehole is at least partially removed with the aid of the cutting edges in order to adapt the inner wall of the borehole to the imaginary cylinder.

The anchor preferably has a core diameter di, where:

0.0 mm <d ₀ - dx <0.7 mm, preferably 0.1 mm <d ₀ - the <0.5 mm.

The anchor preferably has a core diameter d, the thread of the anchor has an outside diameter d _G , and the thread of the cutting tool has a maximum diameter d _F, where:

0.0 <(BB - do) / the <0.15, preferably 0.025 <(BB - de) / the <0.10.

In an advantageous embodiment, the grooving tool, preferably on the side of the grooving thread closer to the trailing end, has an annular stripping element, with drill dust being stripped from the borehole wall with the aid of the annular stripping element when the grooving tool is screwed in and / or unscrewed.

Preferably, the grooving tool has a drive element at its leading end which is suitable for interacting with an application of force by the anchor or a part thereof, and with the aid of which the anchor or part thereof is screwed into the borehole treated with the furrowing tool.

In an advantageous proclamation of the method, the drive element is a polygonal drive or a six-round drive.

In an advantageous embodiment of the method, the insertion of the anchor into the borehole comprises the following steps:

Bringing the drive element of the grooving tool and the force application of the anchor or the part thereof into an engagement position in which the relative orientation of the grooving tool and the anchor or said part thereof is determined such that the screw thread lies on an imaginary continuation of the thread of the anchor, Rotating the grooving tool in the screwing-in direction, a torque being transmitted from its drive element to the force application of the armature or part thereof is to screw the anchor or part thereof into the borehole until the anchor or part of the anchor is completely and the furrowing tool is at least partially in the borehole,

Rotating the grooving tool counter to the screwing direction in order to screw it out of the borehole, whereby it does not transmit any torque from its drive element to the force attack of the anchor or the part thereof.

In an advantageous embodiment, the drive member of the grooving tool, a first abutment surface, the surface normal N with a tangent vector t a Win angle of up to 45 ^0, preferably at most 30 °, and particularly preferably a maximum of 15 ^0, with the tangent vector t is defined as a vector product of an axial vector a, which is directed towards the leading end of the furrowing tool, and a radial vector r, the tip of which lies on the first stop surface (80), so that: t = axr, and where the force application of the armature or said part the same has a first stop surface which rests against the first stop surface of the drive element when the drive element and the force application assume the engagement position.

In an advantageous embodiment of the method, the drive element of the grooving tool has a second stop surface, the surface normal of which has a component in the direction of the axial vector a, and the force application of the armature or said part of the same has a second stop surface, which selements on the second stop surface of the drive applied when the drive element and the force application take the engagement position.

In an advantageous embodiment of the method, the drive element has an axial projection and the force application of the armature has a receptacle in which the axial projection is at least partially received when the drive element and the force application are brought into the engagement position.

In an advantageous embodiment of the method, the anchor is formed by a threaded sleeve or the part of the anchor is formed by a helix, and the receptacle for taking on the axial projection is formed through the interior of the threaded sleeve or the helix.

In all of the described embodiments of the method, a system according to one of the embodiments described above can be used. Another aspect of the invention relates to a method for reinforcing a mineral fastening base, in particular concrete, or for forming an overlapping joint in the mineral fastening base, in particular concrete, using an anchor, in which a method for fastening an anchor in the fastening base according to one of the preceding Embodiments described below are used. The overlap joint can be designed in particular for the purpose of connecting reinforcement, as explained in more detail below.

Another aspect of the present invention relates to an anchor, in particular for a system according to one of the embodiments described above, wherein the anchor is formed in at least two parts, and comprises the following: a helix that can be screwed into an internal thread formed with the aid of a forming tool in a borehole , and a screw or threaded rod with an external thread which is suitable to be screwed into the helix, the ratio of the length h _{eff of} a threaded section of the anchor formed by the helix (44) and the nominal diameter d _{b of} the borehole following The following applies: h _eff / d _b > 10.0, preferably> 12.0, particularly preferably> 15.0, and in particular> 30.0.

The helix is preferably formed by a wound profile strip which has a radially inner and a radially outer side, with a thread ridge being formed on the radially outer side which is suitable for being screwed into the internal thread formed with the aid of the forming tool in the borehole. The threaded rod can be formed by a formwork rod. Preferably, the screw or threaded rod has a cross-sectionally rectangular or trapezoidal thread with a flattened thread tip. All of the advantages and features described above in connection with the two-part anchor of the system also relate to the two-part anchor according to this aspect of the invention.

Although the embodiments described above for the system for fastening an anchor in a borehole, for the method for fastening an anchor in a borehole in a mineral substrate and for the method for reinforcing a mineral fastening substrate or for forming an overlap joint in the mineral substrate always have been described in the context of a particular grooving tool, the present disclosure is not so limited. In all Embodiments described above may also use other forming tools that only optionally have any of the features of the preferred forming tool described above, as long as they are suitable for forming an internal thread in the borehole. In particular, methods and systems for reinforcing a mineral base or for forming an overlap joint as well as one-part or two-part anchors with suitable dimensions that are not known from the prior art, even without reference to the specifically disclosed grooving tool, are the subject of the present disclosure.

BRIEF DESCRIPTION OF THE FIGURES

Fig. La - le show different views of a first embodiment of a furrowing tool,

2a-2d show different views of a second embodiment of a furrowing tool,

3 shows the components of a two-part anchor, FIG. 4 shows a side view and a sectional view of a two-part anchor in the assembled state,

5 shows a side view and a sectional view of a further two-part anchor in the assembled state,

Fig. 6 shows a side view and a sectional view of a further two-part anchor consisting of a screw and a helix in the assembled state, the screw comprising a steeply inclined flank which is suitable for spreading the helix under tensile load,

7 shows a side view, a sectional view and an enlarged section of the sectional view of a further two-part anchor which, in addition to a screw and a helix, comprises an intermediate helix with an inclined flank, which is suitable for spreading the helix under tensile load,

Fig. 8 shows a side view and a sectional view of a monolithic threaded sleeve with locking elements for forming a locking connection, Fig. 9 shows a side view and a sectional view of a wound threaded sleeve with locking elements for forming a locking connection, and Fig. Io shows a sequence of sectional views of the Threaded sleeve of Fig. 8, into which a connection piece is snapped, Fig. Ii shows a schematic sectional view of a connection reinforcement which is implemented with the aid of a two-part anchor, Fig. 12 shows a schematic sectional view of a connection reinforcement which is implemented with the aid of a threaded rod with a concrete screw thread, Fig. 13 shows a side view of a furrowing tool with a drive element, which allows an anchor or part of an anchor to be completely sunk in the mounting base,

14 shows a perspective view of the furrowing tool from FIG. 13, FIG. 15 shows a side view of the furrowing tool from FIGS. 13 and 14, which is in an engaged position with a helix of a two-part armature,

FIG. 16 shows a side view similar to FIG. 15, but in a situation in which the furrowing tool has left the engagement position. DESCRIPTION OF THE PREFERRED EMBODIMENTS

In Fig. La-id (collectively also referred to as “Fig. 1”) different views of a grooving tool 10 according to a first embodiment are shown. FIG. 1b shows a partially sectioned side view, FIG. Tc shows a view of the end that leads during screwing in, the left end in the illustration of lb, FIG. Ta shows a plan view of the end that traces during screwing in, right end in view of FIG Figure 1d shows a cross-sectional view in the direction of arrows B in Figure 1b. Fig. Le shows an enlarged section of Fig. Id.

The furrowing tool 10 has an approximately cylindrical base body (see FIG. 1b) with a leading end 12a and a trailing end 12b. At the trailing end 12b, a force application 14 is attached, which is a receptacle 16 (see Fig. Ta) for taking on a hexagonal tool. With this hexagonal tool, a torque for screwing the furrowing tool 10 into a borehole (not shown) for furrowing an internal thread in the borehole can be transmitted to the base body 12. The other end of the hexagonal tool could then be clamped into the chuck of a drilling machine in order to be screwed in with the aid of the drilling machine. Instead of the force attack 16 for receiving a hexagonal tool, a shaft could also be permanently attached to the trailing end 14, which could be clamped directly into the drill chuck of a drill and which would also be regarded as a "force application" within the meaning of the invention. The application of force does not necessarily have to be provided on the trailing end 12b, but it should at least be accessible from the trailing side (i.e. from outside the borehole). The advantage of the embodiment shown here, however, is that the furrowing tool 10 can be used for drill holes of any depth, and only the appropriate hexagonal tool needs to be selected.

On the outer surface of the base body 10, a self-tapping thread 18 is formed, which in the embodiment shown has fewer than three complete turns. Due to the comparatively small number of turns of the thread 18, the screwing forces can be restricted. The outer diameter of the thread 18 decreases, as can be seen specifically in Fig. Lb, from in the direction of the leading end 12a. In the thread 18 recesses 20 are formed, and between adjacent recesses 20 cutting teeth 22 are formed. The recesses 20 correspond to the respective height of the threading 18 so that the thread 18 is interrupted in sections. In alternative embodiments, however, the recesses 20 do not have to extend all the way to the upper surface of the base body 12.

In the embodiment of FIG. 1, five elevations 24 are formed on the outer surface of the base body 12, each having a cutting edge 26. The elevations 24 have a “rib shape”, which can be seen particularly well in FIG. As can be seen in FIG. 1e, the cutting edge 26 is formed by an edge at which an “essentially radial surface” 28 and an “essentially tangential surface” 30 abut one another. It shows the surface normal 32 of the essentially radial surface 28 in the screwing direction, ge more precisely in the direction of rotation when screwing. The "substantially radial surface" 28 is a surface that is directed at least approximately perpendicular to the borehole wall, and more specifically a surface which is less than 30 °, preferably less than 15 ⁰ relative to the Radi inclined alrichtung. The “essentially tangential surface” 30, on the other hand, is a surface that is at least more parallel to the borehole wall than perpendicular to it. More specifically, it is a surface which is opposite to the radial direction inclined by at least 45 ^0th

The cutting edges 26 of the elevations 24 all rest at least in sections on an imaginary cylinder with a diameter d ₀ . Half the diameter d _{_0/2} of _the imaginary cylinder is located in the embodiment of Fig. 2b. The cutting edges 26 are suitable for at least partially removing the inner wall of the borehole when screwing the furrowing tool 10 into the borehole in order to adapt the inner wall of the borehole to the imaginary cylinder. Vividly speaking, with the help of the elevations 24, the borehole, which has a helical shape due to its production with a hammer drill, is adapted to a cylindrical shape with a predetermined diameter d ₀ by a grinding removal process through the cutting edges 26 of the elevations 24. This makes it possible to use an anchor with a comparatively large core diameter that is in close contact with the borehole wall practically everywhere (and not just in places, as in the case of an untreated borehole) without the frictional forces between the borehole wall and the anchor core being excessive when screwing in increase. Overall, the volume between the borehole wall and the anchor core can be significantly reduced over the entire length of the anchor, whereby the supporting effect of the concrete bracket and thus the load-bearing capacity can be increased significantly. It should be noted that the elevations 24 are arranged between two turns of the forming thread 18. Although it would in principle also be possible to provide the elevations 24 on the leading end 12a of the base body 12, the selected embodiment allows better guidance of the cutting edges along the outer surface of the imaginary cylinder and ultimately a better quality of the treated borehole.

In the area of the trailing end 12b, an annular stripping element 32 is provided, with which drilling dust can be stripped from the borehole wall. In the prior art, the drilling dust is sometimes considered useful in order to fill the spaces between the core and the concrete matrix and thereby create a supporting effect. In the embodiment shown, however, a different approach is taken. Here, the drilling dust is largely kept away from the composite, and instead the supporting effect is brought about by a small distance between the core of the anchor and the as yet undamaged concrete matrix.

Finally, at the leading end 12a of the base body 12, a drive element 34 is seen (see in particular Fig. Tc), which is intended to interact with a drive of an associated armature (not shown). This facilitates the process of setting the anchor, because the tool does not need to be changed between the grooving of the thread and the insertion of the anchor.

The forming tool shown in FIG. 1 can be produced inexpensively by forming. The forming tool is hardened after forming in order to obtain a Rockwell hardness of at least 55 HRC, preferably at least 60 HRC, overall, but at least in its forming thread 18 and the elevations 24.

FIG. 2 shows an alternative embodiment of a forming tool 10, the structure of which corresponds essentially to that of FIG. 1, and the components of which are therefore denoted by the same reference numerals. A renewed detailed description can therefore be omitted. The furrowing tool 10 shown in FIG. 2 is to be produced in a machining process, which allows greater degrees of freedom in the formation of the details, but at the same time increases the costs. While in the embodiment of FIG. 1, the base body 12 was cylindrical in order to permit production in a rolling process, the base body is slightly conical in the case of the furrowing tool of FIG. Note that the outer diameter d _{F of} the forming thread 18 of the forming tool 10 is shown in FIG. 2a.

Fig. 3 shows a two-part anchor 40, consisting of a threaded rod 42 and a helix 44. The threaded rod 42 is in this case by a formwork anchor rod formed a so-called Bi5 thread, as it is commercially available from BETOmax. Such threaded rods are inexpensively available Lich in virtually any length. Fig. 3 also shows a magnified portion of the thread of the threaded rod 42. As seen therein, the threaded rod 42 has a thread 46, with two thread flanks 48, which are relative to the radial direction in each case inclined by 45 ^0th Furthermore, the thread is trapezoidal in cross section and has a flattened thread tip 50.

The helix 44 is formed by a wound profile band which has a radially inner and a radially outer side, a thread ridge 52 being formed on the radially outer side. The profile strip can be produced in a cost-effective rolling process, with the hardness of the thread burr 52 not being subject to any special requirements due to the pre-cut internal thread in the borehole (not shown). The helix 44 can therefore be produced inexpensively and in practically any length. Note that the side edges of the profile band are bevelled so that they have the same inclination as the flanks 48 of the thread 46 of the threaded rod 42.

To set the two-part anchor 40, a hole is first drilled in a mineral underground, and with the aid of the furrowing tool 10, as shown in FIGS. 1 and 2, an internal thread is cut in the borehole. At the same time, the borehole wall is processed by the elevations 24, so that the borehole is at least approximated to an ideal cylindrical shape. Subsequently, the helix 44 is screwed into the borehole, with the thread degrat 52 engaging the grooved internal thread in the borehole. For this purpose, the slope of the helix 44 is adapted to the slope of the furrow thread 18 of the furrowing tool 10. Finally, the threaded rod 42 is screwed into the helix 44 located in the borehole. This is shown in FIG.

As can be seen from FIG. 4, the width, thickness and shape of the profile band forming the helix 44 (especially with regard to the beveled edges) is designed in such a way that it fills the spaces between the threads of the thread 46. In this case, the radially outer side of the profile band and the flattened thread tip 50 together form the core or “core section” of the two-part anchor, and the diameter d _{0 of} the imaginary cylinder is adapted to its diameter di (see FIG. 4) on which the cutting edges 26 of the furrowing tool used for furrowing rest. The Ge thread or the “thread section” of the two-part armature 40 is formed by the thread ridge 52 and has an outer diameter d _G , which is also shown in FIG. 4.

It should be noted that the two-part anchor 40, due to the spatial separation of the helix 44 and the threaded rod 42, has the ability to “expand” in the borehole under load. If an axial force acts on the helix 44 under load, it has the tendency to slide up the respective thread flank 48 of the thread 46 of the threaded rod 42, that is to say to move radially outwards. In this way, the two-part anchor can follow an enlargement of the borehole due to cracking to a certain extent by expanding. It is beneficial for this if the static friction between the helix 44 and the threaded rod 42 is comparatively low, so that the thread ridge 52 of the helix 44 remains in close contact with the mineral substrate at all times, and the relative movement only between the helix 44 and the threaded rod 42 takes place. For this purpose, the helix 44 is coated in preferred embodiments on its radially inner side and on the beveled edges with a sliding layer which lowers the coefficient of static friction m _H. The coefficient of static friction is preferably in the range 0.05 <Lin <0.50, with the following preferably also applies: 0.075 ^ ün, preferably 0.125 <m _H and / or m _H <0.25, preferably m _{H <} 0.20.

FIG. 5 shows a closely related embodiment of a two-part anchor 40, with the difference that the profile band is made narrower than in the embodiment of FIG. 4. As a result, the permitted relative movement between threaded rod 42 and helix 44, and so that the adaptation to crack formation in the concrete is increased.

Fig. 6 shows a side view and a sectional view of another two-part anchor 40 consisting of a screw 43 and a helix 44 in the assembled state, where the screw 43 has a thread 46 which has a strongly inclined flank 48 on its rearward side in the screwing direction relative to the radial direction significantly exceeds the inclination of 45 ^0th Such steeply inclined flanks, with inclination angles with respect to the radial direction of 55 ⁰ or more, preferably 6o ° or more, and particularly preferably 65 ° or more are particularly suitable for spreading. It should be noted that the helix 44 is adapted to this strongly inclined thread flank 48. Specifically, the helix 44 has an inclined support surface 45 which has at least approximately the same angle to the radial direction as the strongly inclined flank 48 of the thread 46 of the screw 43.

7 shows a side view, a sectional view and an enlarged detail of the sectional view of a further two-part anchor which, in addition to a screw 43 and a helix 44, includes an intermediate helix 54 with an inclined flank 56 that is suitable for spreading the helix 44 under tensile load . It should be noted that in the present disclosure a “two-part anchor” is always an anchor that consists of at least two parts, but can also contain further parts, such as the intermediate helix 54 in the case shown. The function of the intermediate helix 54 is to provide the inclined flank 56 so that the screw 43 or, alternatively, a threaded rod 42 in turn does not such a strongly inclined flank 48 needs to have. In this way, screws 43 or threaded rods 42 with standard threads can be used, such as the above-mentioned Bi5 thread. When the two-part anchor of FIG. 7 is subjected to tensile load, the bearing surface 45 of the helix 44 on the inclined surface or flank 56 of the intermediate helix 54 in the direction of the leading end of the screw 43, whereby the helix 44 is spread open as a whole .

8 shows a side view and a sectional view of a monolithic threaded sleeve 58 on which an external thread 60 is formed. Such a threaded sleeve also forms an “anchor” within the meaning of the present disclosure, in which the “threaded section” is formed by the external thread 60, which, as shown in FIG. 8, has an external diameter d _G. The area between two adjacent turns of the thread 60 forms a “core section” in the sense of the present disclosure with a diameter di (see FIG. 8). As can be seen in the sectional view, an annular locking element 62 is provided in the interior of the threaded sleeve 58 for forming a locking connection with a connection piece 64, which is shown in FIG. Fig. 9 shows a similar embodiment of a threaded sleeve 58, which, however, is not monolithic, but is wound from a profile band. Such a wound sleeve can be produced more cost-effectively than a monolithic one. Since in the context of preferred embodiments of the invention, the Ge threaded sleeve is screwed into a pre-formed internal thread in the borehole, so it is not even used for furrowing the thread, the required Verschraubmo elements for screwing the threaded sleeve 58 are limited. In this respect, the reduced torsional stiffness of a wound threaded sleeve 58 compared to a monolithic sleeve 58 is unproblematic in many applications. Instead of the annular locking element 62, an internal thread can also be provided in the interior of the threaded sleeve 58, into which, for example, a screw with a metric thread can be screwed.

FIG. 10 shows a sequence of sectional views of the threaded sleeve 58 from FIG. 8, into which a connection piece 64 is locked. For this purpose, the connecting piece 64 comprises latching hooks 66 which are resiliently mounted and are suitable for latching onto the annular latching element 62. The ring-shaped latching element 62 and the latching hooks 64 form a type of snap connection, via which the connecting piece 64 can be easily attached in the threaded sleeve 58. The connection piece 64 can for example be made of plastic, and can be used for example to attach insulating materials to a wall or ceiling. For such applications, the threaded sleeve 58 could also be made of plastic. For fire protection reasons, however, both the threaded sleeve 58 and the connection piece 64 can be made of metal. 11 shows a sectional view of a so-called connecting reinforcement. In concrete construction, connecting reinforcement is the term used to describe comprehensive reinforcement in the area of working joints, for concreting sections or for precast concrete parts for later frictional connection with so-called in-situ concrete, i.e. fresh concrete that is placed in components in their final position on the construction site and hardens there. Reference numeral 70 denotes an already existing concrete part which is reinforced with a conventional reinforcing rod 74 made of steel. It should be noted that in the present disclosure, as is customary in the technical field, the terms “reinforcement” and “reinforcement” are used synonymously. Reference numeral 72 denotes an attachment which was subsequently concreted onto the existing concrete part 70 using in-situ concrete.

As explained above, the reinforcing bars for connecting reinforcement in the prior art are introduced using a complex adhesive or bonding process, which involves laborious cleaning of the borehole with multiple flushing and blowing, metered filling with mortar or compound, introduction of the reinforcing rod and curing of the compound includes over several hours. The subsequently introduced reinforcement bar forms an overlap joint with the existing reinforcement bar 74, for which certain overlap lengths according to DIN EN 1992-1-1 must be adhered to. In the connection reinforcement shown in FIG. 11, a two-part anchor 40, as described in connection with FIGS. 3 to 5, and which is formed by a threaded rod 42 and a helix 44, is used instead of a further conventional reinforcing rod. This two-part anchor can be set much easier and faster than a conventional reinforcing rod using the conventional adhesive or composite method. After the two-part anchor 40 has been placed in the overlap joint, the attachment 72 can be made with in-situ concrete.

FIG. 12 shows a connection reinforcement similar to FIG. 11, with the only difference that instead of the two-part anchor 40, a threaded rod 76 with a concrete screw thread is used. In the present disclosure, a “concrete screw thread” is understood to be a thread which is designed to be screwed directly into a concrete substrate, ie without using dowels or the like. The person skilled in the art can readily distinguish a concrete screw thread from a thread for other purposes, in particular from a wood screw thread or a thread for cooperation with a nut (for example a metric thread) and the like. In the present disclosure, “concrete screw thread” is understood to mean in particular a thread which - apart from its length - resembles a thread in its geometry that is used in a concrete screw with a technical approval in Europe or the USA on the priority date of the present application . When “Concrete screw thread” is also understood in the present disclosure as a thread with a geometry which, if used in a screw with a permissible length, would receive a European technical assessment / approval (ETA) according to the priority date of the present application. In Fig. 12 is an enlarged view of part of the threaded rod 76 is shown in which the outer diameter of the thread deabschnitts d _G and the core diameter _{K of} the core section are shown.

Instead of the threaded rod 76, a concrete screw could also be used which has a head at its trailing end, that is to say on the right in the illustration of FIG. 12. It should be noted that sufficiently long screws or threaded rods with concrete screw threads, with which a connecting reinforcement, as shown schematically in FIG. 12, could be made, to the knowledge of the inventors in the prior art are not known because they are for the herein described purposes have not been taken into account, and such lengths for conventional applications in concrete are not considered. On the contrary, according to EAD 330232-00-0601, the effective anchorage depth for screw anchors in concrete must not exceed eight times the nominal diameter d _{b of} the borehole, so that known screw anchors for use in concrete usually have threads with a length that is eight times the nominal diameter d _b of the borehole not or al least only slightly exceeds. The length of the threaded rod 76 shown schematically in FIG. 12, on the other hand, in the applications provided here, can exceed the nominal diameter d _b by more than ten times, preferably more than twelve times, particularly preferably more than fifteen times and in particular more than thirty times. Since the concrete screw thread is formed over the entire length of the threaded rod 76, the "length of the threaded section" mentioned at the beginning is identical to the length of the threaded rod 76. Despite the relatively large anchoring depth in the concrete part 70, the threaded rod 76 with concrete screw thread can be compared with Screw in low screw-in torques because the internal thread in the borehole can be previously grooved with a grooving tool 10 according to one of the embodiments described here.

In preferred embodiments, the threaded rod 76 is manufactured with a manufacturing tolerance of less than 0.2 * (d _b ) ⁰ _' ³ mm in relation to the core diameter di, and the forming tool 10 in relation to the diameter d _{0 of} the imaginary cylinder which the cutting edges 26 lie, with a manufacturing tolerance of less than 0.1 · (d _b ) ⁰ _' ³ mm, and the following applies: 0.0 mm <d ₀ - di <0.7 mm, preferably 0.1 mm <d ₀ - di <0.5 mm. As explained at the beginning, the nominal diameter d _{b of} the borehole corresponds to the size specification of a drill to which the anchor is matched, in millimeters, but is itself dimensionless. The manufacturing tolerances are scaled to the power of 0.3 of the nominal diameter d _b . With this dimensioning, there is a very small volume between the core of the destange 76 and the borehole wall. Nevertheless, excessive screwing-in torques can be avoided if the borehole wall is machined with the above-described forming tool 10, so that the friction between the core section and the borehole wall can be kept comparatively low. As a result, for the reasons explained above, high load capacities result in practice.

In preferred embodiments, the threaded rod is in relation to the outer diameter D _G of its thread with a manufacturing tolerance of less than 0.2 · (d _b) ⁰ ³ mm _'set 76 here, is the grooving tool (10) with respect to the maximum outer diameter d _F be nes self-tapping thread 18 also produced with a manufacturing tolerance of less than 0.2 (d _b ) ⁰ _' ³ mm, and the following applies:

0.0 <(dF - dü) / di <0.15, preferably 0.025 <(dF - de) / die <0.10

Here, the reference to the “maximum outside diameter d _{F of} the threading thread 18” takes into account, as mentioned at the beginning, the fact that the threading 18 of the threading tools 10 shown in FIGS. 1 and 2 has a variable outside diameter in order to form a gate. For the depth of the ultimately grooved internal thread, however, only the maximum external diameter d _F (see FIG. 2a) is decisive. The same applies to the concrete screw thread of the threaded rod 76, which can also have an increasing thread diameter at its leading end (not shown in Fig. 12), but the outer diameter of the thread is constant over the major part of the length of the threaded rod 76, and this constant diameter is denoted by d _G. In other words, the outer diameter d _G corresponds to the diameter of the smallest imaginary cylinder into which the thread of the threaded rod 76 can be inscribed as a whole.

In contrast to the prior art cited at the outset, this embodiment expressly does not provide for the outer diameter d _{G of} the thread of the armature to be selected to be greater than the maximum outer diameter d _{F of} the self-tapping thread. While in the prior art a smaller size of the pre-cut internal thread compared to the external thread of the anchor is shown to be advantageous in order to artificially remove substrate particles and to increase the screwing torque for the purpose of a "solid setting feeling", in preferred embodiments the borehole is machined with the aid of the furrowing tool 10 that it is as close as possible to the core section of the respective anchor everywhere. A limiting factor for the anchor diameter remains, despite the machining of the borehole to approximate an ideal cylindrical shape, the friction of the core or core section on the borehole wall and an associated increase in the insertion torque. Preferred execution Forms of the invention therefore avoid the additional screwing resistance, as it is deliberately created in the prior art discussed at the beginning by deformation work at the tip of the Ankerge, in favor of the possibility of choosing the core diameter of the anchor larger, thereby increasing the load-bearing capacity from the initially explained Reasons to increase.

In order to be able to set the threaded rod 76 with concrete screw thread or a correspondingly long concrete screw even easier, it was proposed in connection with the Furchwerk tool 10 of FIGS. 1 to 2d to provide a drive element 34 at the leading end 12a of the base body 12, which is intended to interact with an application of force from a corresponding anchor. In the threaded rod 76, the force application could be, for example, a hexagonal recess, while the drive selement 34 could be formed by a hexagonal drive. In this case, the Ge threaded rod 76 can be screwed into the existing component 70 immediately after the threading of the thread in the borehole using the same machine that was used for the cutting without having to change the tool. Note that at the time at which the threaded rod 76 is screwed into the fastening base 70, the attachment 72 is not yet present, and both the trailing end of the threaded rod 76 with power drive (ie the right end in FIG. 12) as The furrowing tool 10 (not shown in Fig. 12) used to penetrate the hen always remains outside the mounting base 70.

In some applications, however, it may be necessary or desirable to completely sink the anchor, or in the case of a two-part or multi-part anchor, a part of the same in the existing component 70. This applies, for example, to the helix 44 of the two-part armature 40 shown in FIG. 11, which is screwed completely into the existing component 70. A simple hexagonal drive element at the leading end of the furrowing tool 10 is not suitable for these purposes. In order to completely sink the anchor or anchor part in the fastening base 70, the furrowing tool 10 must be screwed at least partially into the borehole again, so that it would typically have to furrow another thread. Furthermore, after reaching the desired insertion depth in the fastening base, the hexagonal drive element of the furrowing tool cannot easily be separated from the force attack when the furrowing tool itself is in the borehole. In order to be able to carry out countersunk screwing in without a tool change, a further forming tool 10 with a drive element 34 suitable for these purposes is described in connection with FIGS. 13 to 16. 13 and 14 show a side view and a perspective view of a Furchwerk tool 10, at the leading end of which a drive element 34 is formed which comprises a first stop surface 80, a second stop surface 84 and an axial projection 88. This drive element 34 is intended to interact with a "force application" of a helix 44, which also has a first stop surface 82, a second stop surface 86 (which in the exemplary embodiment shown in FIGS. 15 and 16 are simply formed by the edges at the trailing end of the helix 44 are) and comprises a receptacle for receiving the axial protrusion 88 before, which is formed in the present case by the cylindrical interior 90 of the helix 44.

The drive element 34 of the furrowing tool 10 and the force application of the helix 44 can assume an engagement position, which is shown in FIG. 15, and in which the first surfaces 80, 82 and the second surfaces 84, 86 of the drive element 34 and the force application abut one another , and in which the axial projection 88 of the drive element 34 in the receptacle, i. H. is received in the axial interior 90 of the helix 44. It can be seen that the drive element 34 of the furrowing tool 10 and the force application of the helix 44 are coordinated with one another in such a way that in this engagement position the relative alignment of the furrowing tool 10 and the helix 44 is determined in such a way that the self-tapping thread 18 is on an imaginary continuation of the thread 52 of the helix 44, when the furrowing tool 10 is rotated in the screwing-in direction, a torque can be transmitted from its drive element 34 to the "force application" of the helix 44, which in the present example is simply formed by the trailing end of the same, and when the furrowing tool is rotated 10 against the screwing-in direction, no torque can be transmitted from the drive element 34 of which to the force application of the helix 44.

Since the grooving tool 10 and the helix 44 are aligned with respect to one another in the engagement position shown in FIG. 15, that the grooving thread 18 lies on the imaginary continuation of the thread 52 of the helix 44, the grooving tool 10 can, when the helix is countersunk 44 can be screwed again into the borehole (not shown in FIGS. 15 and 16) without forming a further thread, because the threading 18 through the synchronization with the thread 52 of the helix 44 described above automatically into the already existing grooved thread in the Borehole is guided. As long as the furrowing tool 10 is rotated in the screwing direction, it also transmits a torque from its drive element 34 to the force applied by the helix 44, so that it is screwed into the thread furrowed in the borehole. When the helix 44 has reached the desired insertion depth, as shown for example in FIG. 11, the direction of rotation of the furrowing tool 10 becomes vice versa so that it is screwed out of the borehole. In this reverse direction of rotation, no torque is exerted on the force applied by the helix 44, so that the helix 44 remains in the sunk position in the fastening base 70. Depending on the type of anchor / anchor part to be screwed in, various drive elements and associated force applications can be provided that offer the functionality described here, i.e. the synchronization of the self-tapping thread 18 and anchor thread 52, torque transmission in the screwing direction and no torque transmission against the screwing in direction. It is emphasized that this aspect of the invention is not limited to a specific design of drive element 34 and force application. However, drive elements 34 have proven to be particularly suitable which have a first stop surface, the surface normal n of which at least approximately corresponds to a tangential vector t, which at all times indicates the direction in which the first stop surface 80 is due to the rotation (but not of the axial advance) of the furrowing tool 10 is moved in the screwing direction in order to be able to effectively transmit a torque to an associated first stop surface 82 of the force application. The vectors n and t are drawn in FIG. Specifically, the surface normal of the first stop surface 80 with the Tangen should tialvektor t a maximum angle of 45 ^0, preferably at most 30 °, and particularly preferably a maximum of 15 before forming ^{the 0th} This can be seen, for example, in FIG. 13, in which it can be seen that the angle between the vectors n and t is comparatively small and, in the present case, corresponds to the pitch angle of the threads 18, 52. For pure torque transmission, it would be preferable if the surface normal n corresponds exactly to the tangential vector t, but the geometry shown has the advantage that the manufacture of the “power drive” for the helix 44 is simplified, which here is simply due to the edges 82, 86 is formed at the trailing end of the wound profile band from which the helix 44 consists.

The tangential vector t can be mathematically defined as a vector product of an axial vector a, which is directed towards the leading end of the grooving tool, and a radial vector r, the tip of which lies on the first stop surface, so that: t = axr, see in particular Fig. 14.

The first stop surfaces 80 and 82, which are aligned as described, generally allow a torque to be effectively transmitted to the force applied by the armature / armature part when the furrowing tool 10 is screwed in. Furthermore, the first stop surfaces 80, 82 help to define the relative alignment of the furrowing tool 10 and the anchor / anchor part in relation to their rotational position when the first stop surfaces 80, 82 abut one another in the mentioned engagement position, thereby synchronizing the anchor thread 52 and the screw thread 18 with respect to their rotational position. When turning out the furrowing tool 10, on the other hand, the first stop surfaces 80, 82 stand out from each other, so that no torque is transmitted from the furrowing tool 10 to the force applied by the anchor / anchor part, and the anchor / anchor part can remain in the ground while the Grooving tool 10 is unscrewed.

Furthermore, it has generally proven to be advantageous if the drive element 34 of the furrowing tool 10, regardless of its specific design, has a second stop surface 84, the surface normal n of which has a component in the direction of the axial vector a, and the power drive of the armature / armature part has one has second stop surface 86 which rests against the second stop surface 84 of the drive element 34 when the Antriebsele element 34 and the power drive assume the engaged position. This criterion is obviously fulfilled with regard to the second stop surfaces 84, 86 in the exemplary embodiment shown in FIGS. 13 to 16. The surface normal n of the second stop surface 84 of the drive element 34 is shown in Fig. 16, and it can again be seen that the surface normal n forms only a small angle with the axial vector a, which in turn corresponds to the pitch angle of the threads 18, 52 . In any case, however, the surface normal n has a (positive) component in the direction of this axial vector a. In preferred forms approximately exporting is the angle between the surface normal n the second stop surface 84 and the axial vector a is less than 45 ^0, preferably less than 30 °. The second stop surfaces 84, 86 help to define the relative alignment of the furrowing tool 10 and the anchor / anchor part with respect to their axial position when the second stop surfaces 84, 86 abut one another in the mentioned engagement position, thereby synchronizing the Anchor thread 52 and the screw thread 18 to ensure their axial position.

Finally, it has generally proven to be advantageous if the drive element 34 has an axial projection and the force application of the armature has a receptacle for receiving the axial projection when the drive element and the power drive assume the engagement position, as in the specific embodiment by the axial projection 88 and the interior space 90 of the coil 44 serving as a “receptacle” is shown. Through the combi nation of an axial projection with a receptacle, a secure engagement between the drive element 34 of the furrowing tool 10 and the force application of the anchor / anchor part can generally be produced.

Although the invention has been described on the basis of specific embodiments, it is understood that the exemplary embodiments shown serve only to illustrate the invention, but do not restrict it. Instead, the invention is only limited by the features indicated in the appended claims.

Claims

EXPECTATIONS

A system for fastening an anchor (40) in a borehole in a mineral substrate, in particular concrete, mortar or masonry, comprising an anchor (40) with a core section and a threaded section (52), the core section having a core diameter _K and the threaded section has an outer diameter d _G , and a forming tool (10) for forming an internal thread in the borehole, the forming tool (10) comprising: an at least approximately cylindrical or conical base body (12) with a leading and a trailing end (12a, 12b ), whereby an application of force is provided via which a torque for screwing the furrowing tool (10) into the borehole and for furrowing the thread on the base body (12) can be transmitted, the base body (12) having an outer surface on which a groove thread (18) is designed, which is suitable for cutting the internal thread into the wall of the borehole, wherein for the ratio of the length h _{eff of} the Gewi nd section of the anchor and the nominal diameter d _{b of} the borehole, the following applies: h _eff / d _b > 10.0, preferably> 12.0, particularly preferably> 15.0, and in particular> 30.0.

2. System according to claim 1, in which the anchor is formed by a screw or threaded rod (76), in which said threaded section is connected to said core section in a non-positive, material or form-fitting manner, the screw or threaded rod (76) preferably consists at least predominantly of corrosion-resistant steel, non-ferrous metal, in particular aluminum or plastic, in particular fiber-reinforced plastic.

3. System according to claim 1, in which the anchor is formed by a threaded sleeve (58) which has an external thread (52) which forms the said threaded section, the threaded sleeve (58) preferably having an internal thread, in particular a metric internal thread, and / or wherein the threaded sleeve (58) is preferably wound from a profile strip which has a radially inner and a radially outer side, a thread ridge (52) being formed on the radially outer side, which is suitable for being inserted into with the aid of the Grooving tool (10) grooved internal thread to be screwed into the borehole, and / or wherein the threaded sleeve (58) consists at least predominantly of corrosion-resistant steel, non-ferrous metal, in particular aluminum or plastic, in particular fiber-reinforced plastic.

4. System according to claim 1, in which the anchor (40) is designed in at least two parts, and comprises: a helix (44) which can be screwed into the internal thread in the borehole formed with the aid of the furrowing tool (10), the helix (44 ) is preferably formed by a wound profile band which has a radially inner and a radially outer side, with a thread ridge (52) being formed on the radially outer side which is suitable for the internal thread in the borehole formed with the aid of the forming tool (10) to be screwed in, and a screw or threaded rod (42) with an external thread (46) which is suitable to be screwed into the helix (44), wherein the threaded rod (42) is formed in particular by a formwork tie rod, and / or wherein the screw or threaded rod (42) preferably has a thread (46) rectangular or trapezoidal in cross section, with a flattened thread tip (50), which at least part of said n core portion of the two-part anchor (40) forms.

5. System according to claim 4, in which the external thread (46) of the screw or threaded rod (42) or an additionally provided intermediate helix (54) arranged between the screw / threaded rod (42) and the helix (44) has at least one inclined flank (48), which is suitable for spreading the helix (44) radially out of the borehole under tensile loads and / or in the direction of the borehole under pressure loads, the at least one inclined flank (48) merging with the radial direction angle of at least 30 °, preferably forms at least 45 ^0, and / or wherein a coefficient of static friction pn between the at least one inclined flank (48) of the screw or threaded rod (42) or intermediate filament (54) and the portion of the helix (44) , which can slide along the inclined flank (48) under the said tensile or compressive load, in a range of 0.05 <PH <0.50, with more preferably: 0.075 ^ PH, preferably 0.125 <P _H and / or p _{H <} 0.25, preferably P _H <0.20, and / or wherein the at least one inclined thread flank, an inclined flank of the intermediate helix (54) and / or a section of the helix (44) that is opened when spreading slides along the inclined flank under load, has a coating that reduces sliding resistance.

6. System according to any one of the preceding claims, wherein on the outer surface of the base body (12) of the furrowing tool (10) a plurality of elevations (24) are formed, each having a cutting edge (26), all cutting edges (26) an imaginary cylinder with a diameter (d ₀ ), and wherein the cutting edges (26) are suitable for at least partially removing the inner wall of the borehole when screwing the forming tool (10) into the borehole in order to adapt the inner wall of the borehole to the imaginary cylinder.

7. System according to claim 6, wherein the cutting edge (26) is formed by an edge on which a substantially radial surface (28) which is inclined relative to the radial direction by less than 30 °, preferably less than 15 ⁰ , and a substantially tangential surface (30), which is opposite to the radial direction inclined by at least 45 ^0, abut one another, wherein the surface normal (32) is substantially radial (28) surface in the screwing.

8. System according to claim 6 or 7, wherein the grooving tool (10) has at least four, preferably at least six of the said elevations (24) with associated cutting edge (26).

9. System according to one of the preceding claims, wherein the anchor (40) is manufactured with a manufacturing tolerance of less than 0.2 · (d _b ) ⁰ _' ³ mm in relation to the core diameter di, the grooving tool (10) in relation to the diameter d _{0 is manufactured} with a manufacturing tolerance of less than 0.1 (d _b ) ⁰ _' ³ mm, where d _{b is} the numerical value of the nominal diameter of the borehole in millimeters, and where:

0.0 mm <d ₀ - di <0.7 mm, preferably 0.1 mm <d ₀ - di <0.5 mm.

10. System according to any one of the preceding claims, wherein the armature (40) is made with a manufacturing tolerance of less than 0.2 · (d _b ) ⁰ _' ³ mm with respect to the outer diameter d _{G of} its thread, the forming tool with respect to the maximum outside diameter d _{F of} its thread is produced with a manufacturing tolerance of less than 0.2 x (d _b ) ⁰ _' ³ mm, where d _{b is} the numerical value of the nominal diameter of the borehole in millimeters and where:

0.0 <(d _F - do) / di <0.15, preferably 0.025 <(d _F - de) / die <0.10.

11. System according to one of the preceding claims, wherein the self-tapping thread (18) has a plurality of turns and the plurality of elevations (24) are arranged between turns of the self-tapping thread.

12. System according to one of the preceding claims, wherein the self-tapping thread (18) has fewer than four turns, preferably between 2.8 and 3.8 turns.

13. System according to one of the preceding claims, wherein the scouring tool (10), preferably on the side of the scoring thread (18) closer to the trailing end (12b), has an annular scraper element (32) which is suitable for scraping drill dust from the borehole wall .

14. System according to any one of the preceding claims, wherein the outer diameter of the thread (18) decreases in the direction of the leading end (12a).

15. System according to one of the preceding claims, wherein recesses (20) are formed in the grooving thread (18) and incisors (22), in particular wedge-shaped incisors, are formed between adjacent recesses, preferably at least some of the recesses (20) of the entire height of the furrow thread (18), so that the furrow thread (18) is interrupted in sections.

16. System according to one of the preceding claims, wherein the furrowing tool (10), but at least its furrow thread (18) and the elevations (24) have a Rockwell hardness of at least 55 HRC, preferably of at least 60 HRC.

17. System according to any one of the preceding claims, wherein the forming tool (10), but at least the forming thread (18) and the elevations (24) consist of an alloy steel, tool steel, stellite, a ceramic material or a hard metal

18. System according to one of the preceding claims, wherein the furrowing tool (10) is intended for multiple use.

19. System according to one of the preceding claims, wherein the furrowing tool (10) at its leading end (12a) has a drive element (34) which is suitable for interacting with a force application of the armature (40) or a part of the same, which is in the screwed in the hole treated with the grooving tool.

20. System according to claim 19, wherein the drive element (34) is a polygon or a six-round drive.

21. System according to claim 19, in which the drive element (34) of the furrowing tool (10) and the force application of the armature (40) are coordinated with one another so that they can assume an engagement position, and in this engagement position the relative orientation of the furrowing tool (10 ) and the anchor (40) or said part of the same is set in such a way that the threading thread (18) lies on an imaginary continuation of the thread of the anchor (40), a torque of the drive element when the threading tool (10) is rotated in the screwing direction (34) can be transmitted to the force application of the armature (40) or part of the same, and when the furrowing tool (10) is rotated counter to the screwing direction, no torque is transmitted from its drive element (34) to the force application of the armature (40) or the part thereof is transferable.

22. The system of claim 21, wherein the drive member (34) of the grooving tool, a first abutment surface (80), whose surface normal n with a tangent vector t a maximum angle of 45 ^0, is preferably maximally 30 ° and particularly preferably a maximum of 15 ^0, The tangential vector t is defined as the vector product of an axial vector a, which is directed towards the leading end (12a) of the grooving tool (10), and a radial vector r, the tip of which lies on the first stop surface (80), so that: t = axr, and wherein the force application of the armature (40) or said part thereof has a first stop surface (82) which rests against the first stop surface of the drive element (34) when the drive element (34) and the force application assume the engaged position .

23. System according to claim 22, wherein the drive element (34) of the furrowing tool (10) has a second stop surface (84), the surface normal of which has a component in the direction of the axial vector a, and the force application of the armature (40) or said part the same has a second stop surface (86) which rests against the second stop surface (84) of the drive element (34) when the drive element (34) and the force application assume the engaged position.

24. System according to one of claims 21 to 23, wherein the drive element (34) has an axial projection (88) and the force application of the armature (40) or said part thereof has a receptacle for receiving the axial projection (88), if the drive element (34) and the force application assume the engagement position.

25. System according to claim 24, wherein the anchor is formed by a threaded sleeve or the part of the anchor (40) is formed by a helix (44), and the receptacle for receiving the axial projection (88) through the interior of the threaded sleeve or the Helix is formed.

26. A method for fastening an anchor (40) with a core section and a threaded section in a borehole in a mineral substrate, comprising the following steps:

Drilling a borehole,

Forming an internal thread in the borehole by inserting a forming tool (10) into the

Borehole is screwed, and

Insertion of the anchor (40) into the borehole, the forming tool (10) comprising: an at least approximately cylindrical or conical base body with a leading and a trailing end (12a, 12b), with a force application (14) being provided over the a torque for screwing the forming tool (10) into the borehole and for forming the thread is transmitted to the base body (12), the base body (12) having an outer surface on which a forming thread (18) is formed which is suitable to furrow the internal thread in the wall of the borehole, characterized in that the armature (40) having an effective anchorage depth h _eff is inserted into the borehole, where h is the ratio of the effective anchorage depth _eff and the nominal diameter d _b of the borehole, the following applies: h _eff / d _{b> 10} .0, preferably> 12.0, particularly preferably> 15.0, and in particular> 30.0.

27. The method according to claim 26, wherein the anchor is formed by a screw or threaded rod (76), in which the said threaded section is non-positively, materially or positively connected to the said core section, the screw or threaded rod (76) preferably consists at least predominantly of corrosion-resistant steel, non-ferrous metal, in particular aluminum or plastic, in particular fiber-reinforced plastic.

28. The method according to any one of claims 26 or 27, wherein the armature is formed by a threaded sleeve (58) which has an external thread (60) which forms the said threaded section, the threaded sleeve (58) preferably having an internal thread, in particular a having a metric internal thread, and / or wherein the threaded sleeve (58) is preferably wound from a profile strip which has a radially inner and a radially outer side, with a thread ridge (52) being formed on the radially outer side which is suitable in the internal thread grooved with the aid of the grooving tool (10) to be screwed into the borehole, and / or wherein the threaded sleeve (58) consists at least predominantly of corrosion-resistant steel, non-ferrous metal, in particular aluminum or plastic, in particular fiber-reinforced plastic.

29. The method according to any one of claims 26 to 28, wherein the anchor (40) is formed in at least two parts, and comprises: a helix (44) which can be screwed into the internal thread in the borehole formed with the aid of the forming tool (10), wherein the helix (44) is preferably formed by a wound profile strip which has a radially inner and a radially outer side, with a thread ridge (52) being formed on the radially outer side, which is suitable for inserting with the aid of the forming tool (10) grooved internal thread to be screwed into the borehole, and a screw or threaded rod (42), with an external thread (46) which can be screwed into the helix (44), the threaded rod (42) being formed in particular by a formwork tie rod, and / or wherein the screw or threaded rod preferably has a thread that is rectangular or trapezoidal in cross section, with a flattened thread tip (50) which at least part of said kerna portion of the two-part anchor (40), and wherein said inserting the anchor (40) into the borehole comprises: screwing the helix (44) into the internal thread in the borehole formed with the aid of the cutting tool (10), and

Screwing the screw or threaded rod (42) into the helix (44).

30. The method according to claim 29, wherein the external thread of the screw or threaded rod (42), or an additionally provided intermediate helix (54) arranged between the screw or threaded rod and the helix has at least one inclined flank (48) which is suitable , the helix (44) in the case of tensile loads in one direction out of the borehole and / or in the case of compressive loads in the direction of the Wellbore radially spread apart, wherein the at least one inclined flank (48) with the radial direction forms an angle of at least 30 °, preferably of at least 45 ^0, and / or wherein a coefficient of static friction pn between the at least one inclined flank (48) of the screw or The threaded rod (42) or intermediate helix (54) and the section of the helix (44) which can slide along the inclined flank (48) under the aforementioned tensile or compressive load, in a range of 0.05 <PH <0.50 , where further preferably applies: 0.075 ^ PH, preferably 0.125 <P _H and / or p _{H <} 0.25, preferably P _H <0.20, and / or where the at least one inclined thread flank (48) is an inclined flank of the The intermediate helix (54) and / or a section of the helix (44) which slides along the inclined flank (48) when spread under load has a coating that reduces the sliding resistance.

31. The method according to any one of claims 26 to 30, in which a plurality of elevations (24) are formed on the outer surface of the base body (12) of the furrowing tool (10), each having a cutting edge (26), all cutting edges (26 ) lie on an imaginary cylinder with a diameter (d ₀ ), the inner wall of the borehole being at least partially removed with the aid of the cutting edges (26) when the forming tool is screwed into the borehole in order to adapt the inner wall of the borehole to the imaginary cylinder.

32. The method according to any one of claims 26 to 31, wherein the anchor (40) has a core diameter di, and where:

0.0 mm <d ₀ - the <0.7 mm, preferably 0.1 mm <d ₀ - the <0.5 mm.

33. The method according to any one of claims 26 to 32, wherein the anchor (40) has a core diameter that _, the thread of the anchor has an outer diameter d _G , the thread of the forming tool has a maximum outer diameter d _F , and where:

0.0 <(d _F - de) / die <0.15, preferably 0.025 <(d _F - de) / die <0.10.

34. The method according to any one of claims 26 to 33, wherein the forming tool (10), preferably on the side of the forming thread (18) closer to the trailing end (12b), has an annular stripping element (32), with screwing in and / or turning out of the furrowing tool (10) with the aid of the annular scraping element (32), drill dust is stripped from the borehole wall.

35. The method according to any one of claims 26 to 34, wherein the furrowing tool (10) at its leading end (12a) has a drive element (34) which is suitable for interacting with a force application of the armature (40) or a part thereof, and with the aid of which the anchor (40) or part of it is screwed into the drill hole treated with the furrowing tool (10).

36. The method according to claim 35, wherein the drive element (34) is a polygon or a six-round drive.

37. The method of claim 35, wherein inserting the anchor (40) into the borehole comprises the steps of:

- Bringing the drive element (34) of the furrowing tool (10) and the force application of the armature (40) or the part thereof into an engagement position in which the relative alignment of the furrowing tool (10) and the armature (40) or said part of the same it is determined that the thread (18) lies on an imaginary continuation of the thread of the anchor (40),

- Rotating the furrowing tool (10) in the screwing-in direction, a torque being transmitted from its drive element (34) to the force application of the anchor (40) or the part thereof in order to screw the anchor (40) or the part thereof into the borehole, to the anchor (40) or part of the anchor is completely and the furrowing tool (10) is at least partially in the borehole,

- Rotating the grooving tool (10) counter to the screwing direction in order to screw it out of the borehole, whereby it does not transmit any torque from its drive element (34) to the force application of the anchor (40) or of the part thereof.

38. The method of claim 37, wherein the drive member (34) of the grooving tool, a first abutment surface (80), whose surface normal n with a tangent vector t a maximum angle of 45 ^0, is preferably maximally 30 ° and particularly preferably a maximum of 15 ^0, The tangential vector t is defined as the vector product of an axial vector a, which is directed towards the leading end (12a) of the grooving tool (10), and a radial vector r, the tip of which lies on the first stop surface (80), so that: t = axr, and wherein the force application of the armature (40) or said part thereof has a first stop surface (82) which rests against the first stop surface of the drive element (34) when the drive element (34) and the force application assume the engaged position .

39. The method according to claim 38, wherein the drive element (34) of the furrowing tool (10) has a second stop surface (84), the surface normal of which has a component in the direction of the axial vector a, and the force application of the armature (40) or said part the same has a second stop surface (86) which rests against the second stop surface (84) of the drive element (34) when the drive element (34) and the force application assume the engaged position.

40. The method according to any one of claims 37 to 39, wherein the drive element (34) has an axial projection (88) and the force application of the armature (40) has a receptacle in which the axial projection (88) is at least partially received when the drive element (34) and the force application are brought into the engagement position.

41. The method according to claim 40, wherein the anchor is formed by a threaded sleeve (58) or the part of the anchor (40) is formed by a helix (44), and the receptacle for receiving the axial projection (88) through the interior of the threaded sleeve or the helix is formed.

42. The method according to any one of claims 26 to 41, using an anchor (40) and a grooving tool (10) of a system according to any one of claims 1 to 25.

43. A method for reinforcing a mineral fastening base, in particular concrete, or for forming an overlap joint, in particular for connecting reinforcement, in a mineral fastening base (70), in particular concrete, using an anchor (40), the method being a method for fastening the Anchor (40) in a mounting base according to any one of claims 26 to 31.

44. Anchor (40), in particular for a system according to one of claims 1 to 25, wherein the anchor is designed at least in two parts, and comprises the following: a helix (44) which is formed into an internal thread grooved with the aid of a grooving tool (10) Borehole can be screwed in, and a screw or threaded rod (42) with an external thread (46) which is suitable to be screwed into the helix (44), the ratio of the length h _{eff being} one formed by the helix (44) Thread section of the anchor and the nominal diameter d _{b of} the borehole, the following applies: h _eff / d _{b> 10} .0, preferably> 12.0, particularly preferably> 15.0, and in particular> 30.0.

45 .Anchor according to claim 44, wherein the helix (44) is formed by a wound profile band which has a radially inner and a radially outer side, wherein a thread ridge (52) is formed on the radially outer side, which is suitable in to be screwed into the drill hole using the grooving tool.

46. Anchor (40) according to claim 44 or 45, wherein the threaded rod is formed by a formwork anchor rod (42), and / or wherein the screw or threaded rod (42) has a rectangular or trapezoidal thread with a flattened thread tip (52) .