SETTING TOOL AND METHOD FOR PERCUSSIVELY DRIVING AN ANCHOR ROD INTO A BOREHOLE

Abstract

A setting tool used in a method for percussively driving an anchor rod into a borehole in a substrate has a drive-side end and, in an opposite tool direction, an end facing away from the drive. The setting tool has a tool adapter that forms the drive-side end and is arranged to interact with a driven impact tool. The end facing away from the drive is formed by a receiving element that has a recess arranged to receive part of an anchor rod. The tool adapter and the receiving element are coupled together by a coupling element such that an impact force introduced via the tool adapter is transmitted to an anchor rod arranged in the recess of the receiving element. The coupling element, in particular a coil spring, is arranged to allow for a displacement of at least part of the receiving element transversely to the tool direction.

Claims

1-17. (canceled)

18. A setting tool for percussively driving an expansion anchor into a borehole in a substrate, the setting tool having a drive-side end and, in a tool direction, an opposite end facing away from the drive-side end for receiving the expansion anchor, the setting tool comprising: a tool adapter adapted to interact with a driven impact tool at the drive-side end; a receiving element having a recess arranged at the opposite end to receive part of an anchor rod of the expansion anchor extending in a guide direction away from the setting tool; wherein the tool adapter and the receiving element are coupled to one another such that an impact force introduced at the drive-side end oriented in the tool direction toward the opposite end is transmitted to the anchor rod when received in the recess of the receiving element and oriented in the guide direction; and wherein the tool adapter and the receiving element are coupled by a coupling element including a coil spring such that, during a percussive driving in of the expansion anchor into a borehole, the coupling element allows a displacement of at least part of the receiving element transversely to the tool direction.

19. The setting tool according to claim 18 wherein the tool adapter, the receiving element and the coupling element are arranged such that the impact force is transmitted directly from the tool adapter to the receiving element.

20. The setting tool according to claim 18 wherein the tool adapter, the receiving element and the coupling element are arranged such that the impact force is transmitted directly from the tool adapter to the anchor rod received in the recess of the receiving element.

21. The setting tool according to claim 20 wherein the receiving element is formed as a sleeve having the recess that is open both in a direction toward the opposite end and in a direction toward the tool adapter.

22. The setting tool according to claim 18 wherein at least one of the tool adapter and the receiving element has a thread onto which the coil spring is screwed.

23. The setting tool according to claim 18 wherein the receiving element includes a retaining element that applies a retaining force oriented in the guide direction and directed toward the drive-side end to the anchor rod received in the recess of the receiving element, the retaining force counteracting removal of the anchor rod in the guide direction from the recess.

24. The setting tool according to claim 23 wherein the retaining element includes at least one magnet that applies the retaining force to the anchor rod being a magnetizable anchor rod.

25. The setting tool according to claim 23 wherein the retaining element includes a clamping element that is elastic at least transversely to the guide direction and reduces a cross section of the recess of the receiving element transversely to the guide direction.

26. The setting tool according to claim 25 wherein the clamping element is formed as a U-shaped bracket having arms inserted into two punctures of the receiving element, the two punctures being positioned opposite one another and aligned transversely to the guide direction.

27. The setting tool according to claim 23 wherein the retaining element includes at least two arms that are elastic transversely to the guide direction and are arranged such that the anchor rod received in the recess of the receiving element pushes the at least two arms outwardly against a tensioning force.

28. The setting tool according to claim 23 wherein the retaining element is an elastic pressing element having a recess extending in the guide direction, wherein an inner diameter of the recess of the pressing element is dimensioned to exert a pressing force transversely to the guide direction on the anchor rod received in the recess of the receiving element.

29. A method for percussively driving an expansion anchor into a borehole, the method comprising the steps of: providing a driven impact tool; providing the setting tool according to claim 18 and receiving an expansion anchor in the setting tool; and operating the driven impact tool to drive the expansion anchor into a borehole using the setting tool.

30. The method according to claim 29 including the following steps: picking up the expansion anchor from a magazine by receiving an anchor rod of the expansion anchor in the setting tool; positioning the anchor rod in alignment with the borehole; setting the expansion anchor into the borehole by transmitting an impact force of the driven impact tool to the anchor rod via the setting tool; and removing the setting tool from the anchor rod leaving the expansion anchor in the borehole.

31. The method according to claim 29 including a step of guiding the driven impact tool by a robot.

Description

DESCRIPTION OF THE DRAWINGS

[0065] In the drawings:

[0066] FIG. 1 shows a first embodiment of a setting tool with a coil spring as a coupling element and with a bracket as a retaining element with equally oriented tool direction and guide direction;

[0067] FIG. 2 shows the setting tool from FIG. 1 with an angular offset between the tool direction and the guide direction;

[0068] FIG. 3 shows a second embodiment of a setting tool with annular magnets as a retaining element;

[0069] FIG. 4 shows part of a third embodiment of a setting tool with a cylindrical magnet as a retaining element;

[0070] FIG. 5 shows part of a fourth embodiment of a setting tool with a cylindrical magnet as a retaining element;

[0071] FIG. 6 shows part of a fifth embodiment of a setting tool with an O-ring as a retaining element;

[0072] FIG. 7 shows part of a sixth embodiment of a setting tool with a metal ring as a retaining element;

[0073] FIG. 8 shows part of a seventh embodiment of a setting tool with three arms as a retaining element;

[0074] FIG. 9 shows part of an eighth embodiment of a setting tool with an elastic pressing element as a retaining element;

[0075] FIG. 10 shows part of a ninth embodiment of a setting tool with a coupling element made of an elastomeric material and an O-ring as a retaining element; and

[0076] FIG. 11 shows a mounting device in an elevator shaft when setting an expansion anchor in a borehole.

DETAILED DESCRIPTION

[0077] According to FIG. 1, a setting tool 10 has a tool adapter 12 and a receiving element 14, which are designed as separate components. The tool adapter 12 is aligned in a tool direction 16 and has a drive-side end 18 which also forms the drive-side end of the setting tool 10. The tool adapter 12 has two portions. A first portion 11 has a mainly cylindrical shape with two diametrically opposed grooves 22 running in the tool direction 16. The tool adapter 12 is provided to be received by a chuck 74 of a driven impact tool 76 which is only shown in FIG. 11. The shape of the tool adapter 12 is adapted to the chuck 74 of the impact tool 76. The tool adapter 12 is thus designed and arranged such that it can interact with the driven impact tool 76. The first portion 11 of the tool adapter 12 merges into a second portion 13 which is also mainly cylindrical but is designed to have a larger diameter than the first portion 11. A strike surface 15 closes off the second portion 13 and thus the tool adapter 12 on a side opposite the drive-side end 18. On the outer side, the strike surface 15 has a continuous collar 17. A first external thread 19, onto which a coupling element in the form of a coil spring 21 is screwed, is arranged on the second portion 13.

[0078] The coil spring 21 couples the tool adapter 12 to the receiving element 14 which forms an opposite end 20 of the setting tool 10, which is opposite the drive-side end 18 in the tool direction 16 and faces away from the drive. The receiving element 14 is designed as a mainly hollow cylindrical sleeve which is aligned in a guide direction 9. The receiving element 14 is thus designed as a sleeve that is open in two directions. The receiving element 14 has a second external thread 23 corresponding to the first external thread 19, onto which the coil spring 21 is also screwed. An outer contour of the receiving element 14 tapers in the direction of the tool adapter 12 and at its closure in the direction of the tool adapter 12 has a bevel 25 corresponding to the collar 17 of the strike surface 15 of the tool adapter 12.

[0079] The tool adapter 12 and the receiving element 14 are made, for example, from tool steel. The setting tool 10 has, for example, a length between 100 and 180 mm.

[0080] The receiving element 14 has a recess 24 which is open in the direction of the end 20 facing away from the drive, into which an anchor rod 26 of an expansion anchor 28 aligned in the guide direction 9 is inserted. The recess 24 extends in the guide direction 9 through the entire receiving element 14, so that the anchor rod 26 bears against the strike surface 15 and thus has a contact surface with the tool adapter 12.

[0081] The recess 24 has, for example, a length in the guide direction 9 between 15 mm and 30 mm and an inner diameter between 8 mm and 24 mm. The recess 24 of the receiving element 14 thus receives, in a guided manner, part of the anchor rod 26 extending in the guide direction 9 away from the end 20 facing away from the drive. The anchor rod 26 is made, for example, of galvanically nickel-plated steel.

[0082] The receiving element 14 has a retaining element in the form of a mainly U-shaped bracket 30; only its two arms 31 can be seen in FIG. 1. For receiving the bracket 30, the receiving element 14 has two opposite punctures 52 on its outer side, which run transversely to the guide direction 9. The punctures 52 are so deep that they extend into the recess 24 of the receiving element 14. The bracket 30 is arranged on the receiving element 14 such that its two arms 31 run in the punctures 52 and thus reduce the cross section of the recess 24 transversely to the guide direction 9. In this case, the dimensions of the recess 24, the bracket 30, and the anchor rod 26 are selected such that an anchor rod 26 inserted into the recess 24 pushes the bracket 30 outwards at least temporarily during the insertion. The dimensions can be selected such that an anchor rod 26 inserted into the recess 24 permanently pushes the bracket 30 outwards and the bracket 30 thus exerts a clamping force on the anchor rod 26. It is also possible that the bracket 30 is not permanently pushed outwards by an inserted anchor rod 26; instead, the bracket hooks at least slightly onto the anchor rod 26 when the anchor rod 26 is pulled out, thus exerting a retaining force oriented in the guide direction and directed in the direction of the drive-side end 18 on the anchor rod 26 arranged in the recess 24 of the receiving element 14, which counteracts the removal of the anchor rod 26 in the guide direction 9 from the recess 24 of the receiving element 14.

[0083] In this case, the individual parts are dimensioned and matched such that the retaining force on the anchor rod 26 is greater by at least a safety margin of, for example, 20% than the weight force of the expansion anchor 28.

[0084] The anchor rod 26, and thus the expansion anchor 28, inserted into the recess 24 of the receiving element 14 are thus secured against unintentional removal from the recess 24. The setting tool 10 and thus the inserted expansion anchor 28 could also be aligned vertically downwards without the anchor rod 26 and thus the expansion anchor 28 falling out of the recess 24. As a result, the setting tool 10 can remove an expansion anchor 28 from a magazine 70 (see FIG. 11) in which it is stored in an upright manner.

[0085] When the tool adapter 12 is inserted into the chuck of a driven impact tool and an anchor rod 26 is inserted into the recess 24 of the receiving element 14, an impact force oriented in the tool direction 16 and directed in the direction of the end 20 facing away from the drive and introduced via the tool adapter 12 can be transmitted to the anchor rod 26 arranged in the recess 24 of the receiving element 14 and percussively drive it into a bore 60, shown only in FIG. 11, in a substrate, for example, a shaft wall 62 of an elevator shaft 64 of an elevator system. In this case, the impact force is transmitted directly from the tool adapter 12 via the strike surface 15 to the anchor rod 26.

[0086] In FIG. 1, no force acts transversely to the guide direction 9 on the anchor rod 26 and thus on the receiving element 14. The coil spring 21 thus aligns the receiving element 14 with respect to the tool adapter 12 such that the guide direction 9 and the tool direction 16 are the same. An anchor rod 26 can thus be inserted into the recess 24 of the receiving element 14 and also removed again without any problems, i.e., the setting tool 10 can be removed from an anchor rod 26 driven into a borehole.

[0087] FIG. 2 shows the setting tool 10 in a state in which, due to the course of a borehole into which the anchor rod 26 is driven, the guide direction 9 has an angular offset relative to the tool direction 16, i.e., the two directions run at an angle other than zero to one another. In this case, the coil spring 21 is deflected transversely to the tool direction 16, so that the receiving element 14 is pivoted relative to the tool adapter 12. Therefore, when compared to the depiction in FIG. 1, at least parts of the receiving element 14 have been displaced transversely to the tool direction 16.

[0088] In the state shown in FIG. 2, the anchor rod 26 is also correctly aligned with respect to the receiving element 14, so that the setting tool 10 can be removed from the anchor rod 26 without any problems.

[0089] FIG. 2 shows an angular offset between the guide direction 9 and the tool direction 16 and its compensation is described by means of the coil spring 21. An additional or exclusive transverse offset between the guide direction 9 and the tool direction 16 can also be compensated for in an analogous manner.

[0090] A setting tool 110 according to FIG. 3 is structured similarly to the setting tool 10 according to FIGS. 1 and 2, which is why mainly the differences between the two setting tools will be described. The setting tool 110 also has a tool adapter 112 and a receiving element 114, which are made from a magnetizable material, for example, tool steel. The tool adapter 112 is designed to be mainly cylindrical and is closed on a side opposite a drive-side end 118 by a strike surface 115. The tool adapter 112 has a first external thread 119 onto which a coupling element in the form of a coil spring 121 is screwed.

[0091] The coil spring 121 couples the tool adapter 112 to the receiving element 114 which forms an end 120 of the setting tool 110 that is opposite to the tool direction 16 and faces away from the drive. The receiving element 114 also has a mainly cylindrical basic form. It has a second external thread 123 corresponding to the first external thread 119, onto which the coil spring 121 is also screwed. An outer contour of the receiving element 114 tapers in the direction of the tool adapter 112.

[0092] Analogously to the coil spring 21 from FIGS. 1 and 2, the coil spring 121 thus allows for a flexible coupling between the receiving element 114 and the tool adapter 112.

[0093] The receiving element 114 adjoins the tool adapter 112 in the direction of the end 120 facing away from the drive and forms the end 120 facing away from the drive. The receiving element 114 has a recess 124 which is open in the direction of the end 120 facing away from the drive and into which an anchor rod 26 of an expansion anchor 28 aligned in the guide direction 9 is inserted. The recess 124 has, for example, a length in the guide direction 9 between 15 mm and 30 mm and an inner diameter between 8 mm and 24 mm. The recess 124 of the receiving element 114 thus receives, in a guided manner, part of the anchor rod 26 extending in the guide direction 9 away from the end 120 facing away from the drive. The anchor rod 26 is made of a magnetizable material, for example, galvanically nickel-plated steel.

[0094] The receiving element 114 has a retaining element 130 in the form of three annular magnets 130a, 130b, 130c which are arranged one behind the other in the guide direction 9 around the recess 124 of the receiving element 114. The receiving element 114 has, at least in the region of the recess 124, a cylindrical outer contour onto which the annular magnets 130a, 130b, 130c are pressed. In this case, the magnets 130a, 130b, 130c are arranged offset in the guide direction 9 with respect to the recess 124 in the direction of the drive-side end 118.

[0095] The magnets 130a, 130b, 130c attract the anchor rod 26 and thus hold it in the depicted position, i.e., inserted into the recess 124 of the receiving element 114. The retaining element 130 in the form of the magnets 130a, 130b, 130c thus applies a retaining force oriented in the guide direction 9 and directed in the direction of the drive-side end 118 to the anchor rod 26 arranged in the recess 124 of the receiving element 114, which counteracts a removal of the anchor rod 26 in the guide direction 9 from the recess 124 of the receiving element 114. In this case, the magnets 130a, 130b, 130c are dimensioned such that the retaining force on the anchor rod 26 is greater by at least a safety margin of, for example, 20% than the weight force of the expansion anchor 28.

[0096] The anchor rod 26 inserted into the recess 124 of the receiving element 114 and thus the expansion anchor 28 are thus secured against unintentional removal from the recess 124. The setting tool 110 and thus the inserted expansion anchor 28 could also be aligned vertically downwards without the anchor rod 26 and thus the expansion anchor 28 falling out of the recess 124. As a result, the setting tool 110 can remove an expansion anchor 28 from a magazine 70 (see FIG. 11) in which it is stored in an upright manner.

[0097] When the tool adapter 112 is inserted into the chuck of a driven impact tool and an anchor rod 26 is inserted into the recess 124 of the receiving element 114, an impact force oriented in the tool direction 16 and directed in the direction of the end 120 facing away from the drive and introduced via the tool adapter 112 can be transmitted via the strike surface 115 to the receiving element 114 and from the receiving element 114 to the anchor rod 26 arranged in the recess 124 and thus percussively drive it into a bore 60, shown only in FIG. 11, in a substrate, for example, a shaft wall 62 of an elevator shaft 64 of an elevator system. In this case, the impact force is transmitted directly from the tool adapter 112 via the strike surface 115 to the receiving element 114.

[0098] In the description of the further embodiments of setting tools in connection with FIGS. 4 to 9, mainly the design of the retaining elements will be addressed. In the case of the setting tools according to FIGS. 4 to 8, the coupling between the tool adapter and the receiving element is designed in accordance with FIG. 3 and in the case of the setting tool according to FIG. 9, it is designed in accordance with FIGS. 1 and 2. Similar or identically acting parts are denoted with a reference sign which is higher by a multiple of one hundred than the corresponding reference sign in FIG. 1. The size specifications for individual components of the setting tool 10 in FIG. 1 also apply to all further setting tools described.

[0099] According to FIG. 4, in a setting tool 210 according to a third embodiment, a retaining element is designed as a cylindrical magnet 230. The magnet 230 is arranged in the guide direction 9 between the recess 224 of the receiving element 214 and the drive-side end. For this purpose, a further recess 232 with a somewhat smaller inner diameter, in which the magnet 230 is arranged, adjoins the recess 224 in the direction of the drive-side end. A strike plate 234 adjoins the magnet 230 in the direction of the end 220 facing away from the drive, which is pushed, and thus secured, with a metallic safety ring 236 against a shoulder resulting from the transition from the recess 224 to the further recess 232. The strike plate 234 thus forms a bottom of the recess 224 of the receiving element 214. It consists of hardened steel and protects the magnet 230 from damage.

[0100] According to FIG. 5, in a setting tool 310 according to a fourth embodiment, the receiving element 314 has a multipiece design. A carrier part 339 coupled to the tool adapter (not depicted in FIG. 5) has an external thread 338 at its end 320 facing away from the drive, which is screwed into an internal thread 340 of an intermediate piece 342 of the receiving element 314. The intermediate piece 342 has a mainly hollow cylindrical basic form and is also aligned in the guide direction 9. A strike plate 334 is arranged on the opening of the intermediate piece 342 oriented in the direction of the end 320 facing away from the drive. In the region of the opening of the intermediate piece 342, the intermediate piece 342 has a somewhat larger inner diameter, resulting in a shoulder against which the strike plate 334 can be pushed. A retaining element in the form of a cylindrical magnet 330, which is pushed against the strike plate 334 by means of a press-on element in the form of a slightly pretensioned coil spring 344, adjoins in the interior of the intermediate piece 342 in the direction of the drive-side end. The coil spring 344 is supported both on the magnet 330 and on the carrier part 339.

[0101] At its end oriented in the direction of the end 320 facing away from the drive, the intermediate piece 342 has an external thread 346 which is screwed into an internal thread 348 of an end piece 350 adjoining the intermediate piece 342 in the direction of the end 320 facing away from the drive. The end piece 350, together with the strike plate 334, forms the recess 324 of the receiving element 314 and forms the end 320 facing away from the drive. It has a shoulder which is continuous on the inside and pushes the strike plate 334 against the shoulder of the intermediate piece 342, so that the strike plate 334 is clamped, and thus secured, between the intermediate piece 342 and the end piece 350.

[0102] The intermediate piece 342 and the end piece 350 are made of non-magnetizable material. However, the strike plate 334 consists of magnetizable material. The press-on element in the form of the coil spring 344 can consist of magnetizable or non-magnetizable material.

[0103] The screw connections between tool adapter (not shown), intermediate piece 342, and end piece 350 are all secured, in particular glued.

[0104] FIG. 6 shows a receiving element 414 of a setting tool 410 according to a fifth embodiment and part of an anchor rod 26. The setting tool 410 is constructed very similarly to the setting tool 110 according to FIG. 3. The only difference is that the retaining element of the receiving element 414 is designed as an O-ring 430. The O-ring 430 is arranged in a continuous groove in the inner surface of the recess 424 of the receiving element 414. The O-ring 430 can be viewed as a clamping element that is elastic at least transversely to the guide direction 9 and reduces a cross section of the recess 424 of the receiving element 414 transversely to the guide direction 9. In this case, the dimensions of the recess 424, the O-ring 430, and the anchor rod 26 are selected such that an anchor rod 26 inserted into the recess 424 compresses the O-ring 430, so that it exerts a clamping force on the anchor rod 26.

[0105] FIG. 7 shows a receiving element 514 of a setting tool 510 according to a sixth embodiment and part of an anchor rod 26. The setting tool 510 is constructed very similarly to the setting tool 410 according to FIG. 6. The only difference is that the retaining element of the receiving element 514 is not designed as an O-ring but as a metal ring 530. The metal ring 530 has an inner contour, as a result of which the force for inserting the anchor rod 26 into the recess 524 of the receiving element 514 is smaller than a force for pulling the anchor rod 26 out of the recess 524. This is realized in that an inner diameter of the metal ring 530 decreases slightly both from the drive-side end and from the end facing away from the drive, and the decrease of the inner diameter at the drive-side end is steeper than at the end facing away from the drive.

[0106] FIG. 8 shows a setting tool 610 according to a seventh embodiment. The retaining element 630 is formed by three arms 630a, 630b, 630c that are elastic transversely to the guide direction 9. The arms 630a, 630b, 630c are fastened to the outer surface of the receiving element 614 with two rivets each and form the end 620 of the setting tool 610 facing away from the drive. The arms 630a, 630b, 630c are arranged such that an anchor rod (not depicted) arranged in the recess 624 of the receiving element 614 pushes the arms 630a, 630b, 630c outwards against a tensioning force.

[0107] FIG. 9 shows a receiving element 714 and part of a tool adapter 712 of a setting tool 710 according to an eighth embodiment and part of an anchor rod 26. The setting tool 710 is constructed very similarly to the setting tool 10 according to FIG. 1. The only difference is that the retaining element of the receiving element 714 is formed as an elastic pressing element 730 with a continuous recess 754 in the guide direction 9. An inner diameter of the recess 754 of the pressing element 730 is selected such that the pressing element 730 exerts a pressing force transversely to the guide direction 9 on the anchor rod 26 arranged in the recess 724 of the receiving element 714. The pressing element 730 has a continuous, inwardly aligned collar 756 which dips into a continuous groove 758 of the receiving element 714. The pressing element 730 is thus fixed on the receiving element 714.

[0108] FIG. 10 shows a receiving element 814 and part of a tool adapter 812 of a setting tool 810 according to a ninth embodiment and part of an anchor rod 26. The tool adapter 812 and the receiving element 814 overlap in the tool direction 16 in an overlap region 878. The tool adapter 812 has a mainly cylindrical basic form in the overlap region 878 and the receiving element 814 has a mainly hollow cylindrical basic form. An inner diameter of the receiving element 814 is somewhat, for example, between 4 and 20 mm, larger than an outer diameter of the tool adapter 812. A hollow cylindrical coupling element 821 made of elastomer is clamped and thus arranged between the tool adapter 812 and the receiving element 814 in the overlap region 878. The coupling element 821 thus establishes a frictional connection between the tool adapter 812 and the receiving element 814. The receiving element 814 also has a retaining element 830 corresponding to the retaining element 30 in FIG. 1.

[0109] A method for setting, i.e., for percussively driving an expansion anchor 28 with an anchor rod 26 into a borehole 60 in a substrate designed as a shaft wall 62 of an elevator shaft 64 will be described in connection with FIG. 11. One of the setting tools described herein and shown in FIGS. 1 to 10 is used to drive in the expansion anchor 28. The setting tool 10 is shown as an example.

[0110] The method is carried out at least partially automatically by a mounting device 66 which can be displaced in the elevator shaft 64 by means of a suspension element 68. The mounting device 66 has a magazine 70 in which a plurality of expansion anchors 28 is stored in an upright manner. The mounting device 66 can drill the borehole 60 into the shaft wall 62 in particular with a drilling tool (not depicted). A robot 72 of the mounting device 66 then picks up an expansion anchor 28 from the magazine 70 with a setting tool 10 inserted into a chuck 74 of a driven impact tool 76. For this purpose, the setting tool 10 is moved from above onto the expansion anchor 28 such that the anchor rod 26 of the expansion anchor 28 dips into the recess 24 of the setting tool 10 and the anchor rod 26 is held by the retaining element (not depicted in FIG. 11) of the setting tool 10.

[0111] After an expansion anchor 28 has been picked up with the setting tool 10, the expansion anchor 28 and thus the anchor rod 26 are positioned in alignment with the borehole 60 by means of the robot 72. When the expansion anchor 28 and thus the anchor rod 26 are correctly aligned, the impact tool 76 is activated and the expansion anchor 28 is percussively driven into the borehole 60. For this purpose, an impact force applied by the impact tool 76 is transmitted via the setting tool 10 to the anchor rod 26 of the expansion anchor 28. After the expansion anchor 28 has been driven in, the setting tool 10 is removed from the anchor rod 26. The next expansion anchor can then be driven into a borehole.

[0112] Finally, it should be noted that terms such as “comprising,” “having,” etc. do not preclude other elements or steps and terms such as “a” or “an” do not preclude a plurality. Furthermore, it should be noted that features or steps that have been described with reference to one of the above embodiments can also be used in combination with other features or steps of other embodiments described above.

[0113] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.