SPREADING ANCHOR AND METHOD FOR ITS ANCHORING

Description

[0001] The invention relates to an expansion anchor having the features of the preamble of claim 1 and a method for anchoring the expansion anchor having the features of the preamble of claim 14.

[0002] Patent application EP 0 099 028 A1 discloses an expansion anchor with an expansion sleeve, an anchor shaft, and a frustoconical expansion body arranged coaxially at one end of the anchor shaft. The expansion sleeve is arranged axially displaceably on the anchor shaft at a smaller-diameter end of the expansion body. Longitudinal slots open at a front end facing the expansion body divide the expansion sleeve into expansion tabs that extend over a limited axial section of the expansion sleeve. At their rear ends facing away from the expansion body, the expansion tabs merge via narrow connecting webs into a sleeve-shaped connecting section that connects the expansion tabs to one another.

[0003] For expansion, the expansion body is pulled between the expansion plates and, due to its conical shape, pushes them apart. This is referred to as "expanding the expansion plates" and can also be understood as "expanding the expansion sleeve" or "expanding the expansion anchor." In a particularly cylindrical anchor hole, the expansion body pulled between the expansion plates pushes the expansion plates outward against a hole wall of the anchor hole, so that the expansion anchor is held in the anchor hole by frictional engagement and, if necessary, additionally by positive engagement between the expansion plates of the expansion sleeve and the hole wall. This can be understood as anchoring the expansion anchor in the anchor hole or in the anchor base in which the anchor hole is located.

[0004] From US 1 469 669 A a bolt anchor is known which has an expansion body and an expansion sleeve.

[0005] The object of the invention is to improve the anchoring of an expansion anchor of the type described above in an anchor hole.

[0006] This object is achieved according to the invention by the features of claim 1. The expansion anchor according to the invention comprises an expansion body and an expansion sleeve. In addition to being truncated cone-shaped, the expansion body can also be, for example, truncated pyramid-shaped or wedge-shaped; it can have spherical or hollow peripheral surfaces, or even one or more steps. The expansion body generally has a shape that radially pushes the expansion tabs of the expansion sleeve apart, i.e., spreads them apart, when the expansion body is moved between the expansion tabs, or conversely, the expansion tabs are moved onto the expansion body.

[0007] The expansion sleeve is divided into expansion tabs by longitudinal slots. The longitudinal slots are preferably open at a front end facing the expansion body, so that the expansion tabs are free at their front ends facing the expansion body. The longitudinal slots can run axially parallel or at an angle to the axial parallels of the expansion sleeve, whereby the angle can change along the length of the longitudinal slots. For example, the longitudinal slots can run helically, wave-shaped, or in a zigzag shape. An axial section of the expansion sleeve over which the expansion tabs extend is referred to here as the expansion region of the expansion sleeve.

[0008] A connecting section of the expansion sleeve connects the expansion tabs. The connecting section is located, in particular, outside the expansion tabs and preferably at a rear end of the expansion tabs, remote from the expansion body. The connecting section is, for example, a tubular or sleeve-shaped axial section of the expansion sleeve at the rear end of the expansion tabs.

[0009] The invention provides a positive connection between adjacent expansion tabs and / or the expansion tabs with the connecting section of the expansion sleeve, which connects the adjacent expansion tabs to one another or the expansion tabs with the connecting section by a positive connection acting in a longitudinal direction of the expansion sleeve. The positive connection can be free of play or have play. The latter means limited mobility of the expansion tabs in the longitudinal direction of the expansion sleeve relative to one another and / or to the connecting section of the expansion sleeve. The positive connection between the adjacent expansion tabs prevents or - if it has play - limits movement of adjacent expansion tab edges of the adjacent expansion tabs relative to one another in the longitudinal direction of the expansion sleeve. As a result, the expansion tabs cannot move, or at least only move to a lesser extent, in a circumferential direction of the expansion sleeve or the expansion body during expansion.The expansion of the expansion plates is not reduced, or at least to a lesser extent, by the fact that the expansion plates deflect a longitudinal movement relative to the expansion body during expansion by moving in the circumferential direction. The expansion of the expansion plates and thus the anchoring of the expansion anchor in an anchor hole are improved.

[0010] As mentioned, the positive connection between the expansion tabs and / or between the expansion tabs and the connecting section can be free of play. If there is play, there may be a gap, for example, that is, in particular, at most half the width of the wall thickness of the expansion sleeve.

[0011] To form the positive connection between the adjacent expansion tabs, one embodiment of the invention provides a connecting tab and a recess into which the connecting tab engages. The connecting tab protrudes from a first expansion tab in a circumferential direction of the expansion sleeve. The recess is provided in an expansion tab edge of an adjacent, second expansion tab facing the first expansion tab and / or in the connecting section of the expansion sleeve. The engagement of the connecting tab in the recess prevents or limits movement of the connecting tab in the longitudinal direction of the expansion sleeve and thereby stabilizes the expansion tab against movement in the circumferential direction of the expansion sleeve. The connecting tab protrudes in particular 1 / 4 to 1 / 3 as far in the circumferential direction of the expansion sleeve as the expansion tabs are wide outside the positive connection.

[0012] The connecting tab can also extend obliquely to the circumferential direction and to the longitudinal direction of the expansion sleeve or have one or more edges running obliquely at an angle between in particular 30° and 60°, or at an angle of in particular approximately 45°±5° or 45°±10° to the longitudinal direction of the expansion sleeve.

[0013] One embodiment of the invention provides a connecting plate in the shape of a rectangle arranged obliquely to the circumferential direction and the longitudinal direction of the expansion sleeve. The recess can also have the shape of such a rectangle or, for example, be triangular to accommodate a corner area of ​​the connecting plate. Recesses of other shapes are not excluded.

[0014] According to the invention, the expansion anchor has connecting webs that connect the expansion tabs to the connecting section of the expansion sleeve, so that the expansion tabs are connected to the connecting section via the connecting webs and to one another via the connecting section. The connecting webs are narrower than the expansion tabs are wide in the circumferential direction of the expansion sleeve. The connecting webs facilitate expansion and increase the risk that the expansion tabs will avoid expansion due to movement in the circumferential direction of the expansion body. The invention counteracts the latter by the positive connection of the adjacent expansion tabs to one another and / or to the connecting section of the expansion sleeve. The connecting webs have a maximum width of 80% of the width of the expansion tabs; in particular, the connecting webs are at most 1 / 3 as wide as the expansion tabs and preferably a maximum of 1 / 5 as wide as the expansion tabs.In particular, 1 / 10 of the width of the expansion tabs can be considered the lower limit. Here, the "width of the expansion tabs" refers to the largest width in the circumferential direction of the expansion sleeve outside the form-fitting connections.

[0015] To provide space for the recesses of the form-fitting connection, one embodiment of the invention provides for the connecting webs to be arranged off-center relative to the expansion tabs. In this embodiment of the invention, the connecting webs are offset in the circumferential direction of the expansion sleeve relative to the longitudinal centers of the expansion tabs. In embodiments of the invention, the connecting webs can also be arranged off-center relative to the expansion tabs independently of the form-fitting connection.

[0016] To ensure that the expansion sleeve has sufficient axial hold in the anchor hole to allow the expansion body to be retracted, one embodiment of the invention provides a rotation and sliding locking tab that projects radially outward beyond a circumferential surface of the expansion sleeve and rests against the wall of the anchor hole even when the expansion tabs are not expanded. The "surface surface" is assumed to be the circumferential surface of an imaginary cylinder that encloses the connecting section of the expansion sleeve. The rotation and sliding locking tab, which projects radially outward, also counteracts rotation of the expansion sleeve when subjected to a torque during expansion.

[0017] The connecting tab of the positive connection of the expansion tabs can simultaneously form the anti-rotation and anti-sliding tab by projecting radially outwards so far that it rests against the wall of the anchor hole. The positive connection between the expansion tabs and / or the expansion tabs with the connecting section of the expansion sleeve can exist outside the anchor hole or be created when the expansion sleeve is inserted into the anchor hole by the radially outward-projecting connecting tab, which also forms the anti-rotation and anti-sliding tab, being pressed radially inwards by the wall of the anchor hole into the recess in the facing expansion tab edge of the adjacent expansion tab and / or in the connecting section.

[0018] The expansion sleeve of the expansion anchor according to the invention is, in particular, punched from a sheet metal or separated from the sheet metal in another way, for example by laser cutting, and bent into the expansion sleeve. During punching or other processing, the slots, recesses, etc., are preferably also produced in the expansion sleeve.

[0019] In order that the expansion tabs can widen in the circumferential direction during expansion, in particular with a truncated cone-shaped expansion body, in accordance with the cone shape, one embodiment of the invention provides that the expansion tabs have one or more webs which can lengthen in the circumferential direction of the expansion sleeve due to a change in shape of the webs, in particular due to bending of the webs, during expansion. An expansion of the webs in their longitudinal direction is not intended, but is not excluded either. The webs can, for example, be curved or have the shape of a V, the tip of which points in the longitudinal direction of the expansion sleeve. When the expansion tabs are widened, the webs lengthen in the circumferential direction of the expansion sleeve, as the curve or V becomes flatter.Generally speaking, the webs have at least one web section that runs in the longitudinal direction or obliquely to the longitudinal direction of the expansion sleeve, but not exclusively in the circumferential direction. The web(s) extend in the circumferential direction of the expansion sleeve by changing its position more in the circumferential direction of the expansion sleeve through deformation of the web. Preferably, the web(s) have a plurality of oppositely curved or oppositely oblique web sections that pivot in opposite directions as the web extends in the circumferential direction of the expansion sleeve.

[0020] The web(s) may be formed by one or more openings passing through the expansion tabs and axially offset from one another.

[0021] To improve the hold in the anchor hole, one embodiment of the invention provides one or more edges on an outer side of the expansion sleeve facing away from the expansion body. The edge is located at a transition from an opening in an expansion tab to the outer side of the expansion tab, preferably on a rear edge, which means that the outer side of the expansion sleeve extends from the edge toward the front end of the expansion sleeve facing the expansion body. During expansion, the edge forms into the hole wall of the anchor hole and increases the hold of the expansion sleeve in the anchor hole in the axial direction of the expansion sleeve.

[0022] From the edge forward towards the front end of the expansion sleeve, the outer side of the expansion sleeve preferably runs obliquely and / or in an arc shape inwards. The obliqueness is in particular at least as great as and preferably greater than an angle at which an expansion surface of the expansion body runs obliquely to the axial direction of the expansion anchor. The expansion surface of the expansion body is the surface on which the expansion tabs slide when the expansion body gets between them. This design ensures that the edge of the expansion tab is pressed into the hole wall of the anchor hole even when the expansion tab is pivoted outwards during expansion. The outer side of the expansion sleeve can also only run obliquely inwards at an axial distance from the edge, wherein the distance is preferably no greater than 1.5 mm or 1 mm and preferably smaller.

[0023] A preferred embodiment of the invention provides a chamfer or rounded portion at the front edges of the expansion sleeve, the expansion tabs, and / or the webs of the expansion tabs, i.e. those edges facing the expansion body, at a transition to an inner side of the expansion sleeve facing the expansion cone. This avoids an edge on the inner side of the expansion sleeve that could become formed into the expansion body during expansion and make expansion more difficult. A chamfer angle is preferably at least as large as the angle of the expansion surface of the expansion body to the axis of the expansion anchor, so that no front edge on the inner side of the expansion sleeve strikes the expansion body during expansion. The rounded portion at the transition from the inner side of the expansion sleeve to the front edge(s) of the expansion sleeve, expansion tabs, and / or webs is preferably extended outwards accordingly.

[0024] The features and combinations of features, embodiments and configurations of the invention mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or drawn in a figure can be used not only in the respective combination specified or drawn, but also in basically any other combinations or individually. Embodiments of the invention are possible which do not have all the features of a dependent claim. Individual features of a claim can also be replaced by other disclosed features or combinations of features. Embodiments of the invention which do not have all the features of the exemplary embodiment, but have in principle any part of the identified features of the exemplary embodiment, are possible.

[0025] The invention is explained in more detail below using an exemplary embodiment illustrated in the drawing. In the drawings: Figure 1 shows a view of an expansion anchor according to the invention; Figure 2 shows an enlargement of the expansion anchor from Figure 1 ; Figure 3 a development of an expansion sleeve of the expansion anchor made of Figure 1 ; Figure 4 an axial half-section of the expansion sleeve Figure 3 ; and Figure 5 an enlargement of the axial half-section of the expansion sleeve from Figures 3 and 4 .

[0026] The Figure 1The expansion anchor 1 according to the invention shown in the drawing comprises an anchor shaft 2, an expansion body 3, and an expansion sleeve 4. In the exemplary embodiment, the expansion body 3 is frustoconical and adjoins the anchor shaft 2 with its smaller diameter end coaxially. The smaller diameter end of the expansion body 3 adjoins the anchor shaft 2. In the exemplary embodiment, the anchor shaft 2 and the expansion body 3 are integrally formed; however, they can also be screwed or riveted, for example.

[0027] At a rear end remote from the expansion body 3, the anchor shaft 2 has an external thread 5.

[0028] At an axial distance from the expansion body 3, the anchor shaft 2 has an annular step as an axial abutment 6 for the expansion sleeve 4. The expansion sleeve 4 is arranged axially displaceably on the anchor shaft 2 between the expansion body 3 and the abutment 6.

[0029] The expansion sleeve 4 is, as in Figure 3 to see, punched from a flat sheet or, for example, separated from the flat sheet by laser cutting and to the Figures 1 and 2 shown, cylindrical tube-shaped sleeve bent.

[0030] The expansion sleeve 4 has longitudinal slots 7, which divide it into expansion tabs 8, which extend in a longitudinal direction of the expansion sleeve 4 and are arranged next to one another in the circumferential direction of the expansion sleeve 4. The longitudinal slots 7 begin at a front end of the expansion sleeve 4 and extend - in the exemplary embodiment - over approximately 2 / 3 of an axial length of the expansion sleeve 4. An axial section of the expansion sleeve 4 having the expansion tabs 8 is referred to here as the expansion region 9. The front end here is the end of the expansion tabs 8 and the expansion sleeve 4 facing the expansion body 3. In the exemplary embodiment, the longitudinal slots 7 run parallel to the axis, but they can also run, for example, in a helical, wave-shaped, or zigzag shape (not shown).

[0031] By pulling the expansion body 3 between the expansion tabs 8, the expansion tabs 8 are radially pushed apart by the expansion body 3, which is referred to as spreading of the expansion tabs 8 and can also be understood as spreading of the expansion sleeve 4 and the expansion anchor 1. For spreading, a relative movement between the expansion sleeve 4 or the expansion tabs 8 and the expansion body 3 in the axial direction of the expansion anchor 1 is required; the expansion tabs 8 can also be spread by sliding them onto the expansion body 3.

[0032] In the exemplary embodiment, front edges 10 of the spreading tabs 8 are oblique to the longitudinal axis, which, however, is not mandatory for the invention.

[0033] At the rear ends, remote from the expansion body 3, the expansion tabs 8 taper to form connecting webs 11, which integrally connect the expansion tabs 8 to a connecting section 12 of the expansion sleeve 4. The connecting section 12 is a cylindrical, tubular axial section of the expansion sleeve 4 at an end of the expansion sleeve 4 remote from the expansion body 3, which connects the expansion tabs 8 to one another via the connecting webs 11. In the exemplary embodiment, the connecting webs 11 are less than half as wide as the expansion tabs 8 in a circumferential direction of the expansion sleeve 4, namely approximately 1 / 3 to 1 / 4 as wide as the expansion tabs 8. The connecting webs 11, which are narrower than the expansion tabs 8, facilitate the spreading of the expansion tabs 8.

[0034] At their rear ends, the expansion tabs 8 have connecting tabs 13 that engage in corresponding recesses 14 in a spreading tab edge 15 of an adjacent expansion tab 8. In the exemplary embodiment, the recesses 14 extend in the longitudinal direction of the expansion sleeve 4 from the expansion tabs 8 into the connecting section 12 of the expansion sleeve 4. Designs of the expansion sleeve 4 are also possible in which the recesses 14 are located exclusively in the connecting section 12 or at least outside the expansion tabs 8 (not shown). The connecting tabs 13 and the recesses 14 form effective positive connections 16 in a longitudinal direction of the expansion sleeve 4 between adjacent expansion tabs 8 or between the expansion tabs 8 and the connecting section 12 of the expansion sleeve 4.The form-fitting connections 16 counteract a pivoting of the expansion tabs 8 with their front edges 10 in the circumferential direction of the expansion sleeve 4, or in the circumferential direction of the expansion body 3, around the connecting webs 12 when the expansion body 3 is pulled in between the expansion tabs 8.

[0035] In the exemplary embodiment, the connecting tabs 13 are rectangular and arranged at an angle of 45° to the longitudinal direction or axial direction and to the circumferential direction of the expansion sleeve 4, wherein the connecting tabs 13 merge integrally into a first expansion tab 8 on one side of the rectangle and engage with their other three sides into the recess 14 of an adjacent, second expansion tab 8, which together with the expansion tab 8 form the positive connection 16 between the adjacent expansion tabs 8 or between the first expansion tab 8 and the connecting section 12 of the expansion sleeve 4. Other shapes and orientations of the connecting tabs 13 and the recesses 14 are possible. For example, the connecting tabs 13 can be aligned in a different direction, for example in the circumferential direction of the expansion sleeve 4 (not shown).

[0036] When the expansion tabs 8 are pivoted with their front edges 10 in the circumferential direction of the expansion sleeve 4 or in the circumferential direction of the expansion body 3 around the connecting webs 11 at their rear ends, an edge of the connecting tabs 13 abuts against an opposite edge of the respective recess 14, whereby a relative movement of the expansion tabs 8 in the longitudinal direction of the expansion sleeve 4 is prevented or limited, which prevents or at least limits the pivoting of the expansion tabs 8 in the circumferential direction of the expansion sleeve 4 or the expansion body 3.

[0037] The positive-locking connections 16 can be free of play. In the exemplary embodiment, there is a small gap 17 between the connecting tabs 13 and the recesses 14, i.e., the positive-locking connections 16 between the expansion tab edges 15 have a small amount of play. On two sides of the connecting tabs 13, the gap 17 is at most half the width of the wall thickness of the expansion sleeve 4. On a third side, the gap is wider in the exemplary embodiment, and on the fourth side, the connecting tabs 13 merge integrally into the expansion tabs 8.

[0038] In the exemplary embodiment, the connecting tabs 13 protrude from the expansion tabs 8 by approximately 1 / 4 of the width of the expansion tabs 8 at their widest points in the circumferential direction of the expansion sleeve 4. The connecting tabs 13 can also be shorter in the circumferential direction of the expansion sleeve 4, but preferably, as mentioned, they protrude from the expansion tabs 8 by approximately 1 / 4 of the width of the expansion tabs 8 or more in the circumferential direction of the expansion sleeve 4.

[0039] The connecting webs 11 can be arranged centrally to the expansion tabs 8, i.e., in a center between the mutually facing expansion tab edges 15, whereby the center between the expansion tab edges 5 can be understood as the transverse center of the expansion tabs 8. In the exemplary embodiment, the connecting webs 11 are offset in the circumferential direction of the expansion sleeve 4 relative to the transverse centers of the expansion tabs 8 in order to create space for the form-fitting connections 16.

[0040] As particularly in Figure 2As can be seen on the right side of the expansion sleeve 4, the connecting tabs 13 are bent outward at an acute angle to the axial direction of the expansion sleeve 4, so that - in the exemplary embodiment - a rear corner of the connecting tabs 13, remote from the expansion body 3, protrudes radially outward beyond a circumferential surface of the expansion sleeve 4 by - in the exemplary embodiment - approximately the wall thickness of the expansion sleeve 4. "Current surface" here refers to an imaginary cylindrical surface with the diameter of the expansion sleeve 4 in the region of the connecting section 12. As a result, the connecting tabs 13 rest in a cylindrical anchor hole (not shown) and hold the expansion sleeve 4 in the axial direction so that the expansion body 3 can be pulled between the expansion tabs 8 for expansion or can be generally moved. In addition, the connecting tabs 13 hold the expansion sleeve 4 against rotation in the anchor hole, for example, if a torque acts on the expansion sleeve 4 during expansion.Because the connecting tabs 13 project radially outward to such an extent that they rest against the wall of the anchor hole with preload, they simultaneously form anti-rotation and anti-sliding tabs 18, which, if necessary, hold the expansion sleeve 4 in an anchor hole with limited force against axial movement and rotation. Embodiments of the invention are also possible in which the expansion sleeve 4 has anti-rotation and anti-sliding tabs other than the connecting tabs 13 (not shown).

[0041] The expansion tabs 8 have V-shaped openings 19 which are offset from one another in the longitudinal direction of the expansion sleeve 4 and through which V-shaped webs 20 are formed in the expansion tabs 8, which are offset from one another in the longitudinal direction of the expansion sleeve 4, i.e. 8 V-shaped webs arranged one behind the other in the longitudinal direction of the expansion sleeve 4 and the expansion tab 8. The tips of the Vs are directed forward in the exemplary embodiment. Due to the V-shape, the webs 20 have two web sections 21 on either side of their tips which run obliquely in opposite directions to the longitudinal direction of the expansion sleeve 4. Due to their shape, the webs 20 allow the expansion tabs 8 to widen when they are expanded, so that the expansion tabs 8 adapt to the conical shape of the expansion body 3 and can widen according to the conical shape when the expansion body 3 is pulled between the expansion tabs 8 for expansion.

[0042] It is not necessary for the webs 20 to expand in order to widen the expansion tabs 8; rather, the widening of the expansion tabs 8 is possible by changing the shape of the webs 20. The V-shape of the webs 20 becomes flatter and the web sections 21 on either side of the tips of the Vs pivot such that their angles to the circumferential direction of the expansion sleeve 4 become smaller. A reduction in the angles to the circumferential direction of the expansion sleeve 4 of the web sections 21 of the webs 20 that run obliquely to the circumferential direction and the longitudinal direction of the expansion sleeve 8 means an increase in the angles of the web sections 21 to the longitudinal direction of the expansion sleeve 4. The change in shape of the webs 20 to widen the expansion tabs 8 is a bending of the webs 20. The webs 20 can also have a different shape; for example, the webs 20 can be arcuate (not shown).Their shape and arrangement are selected such that they can increase their length or their extension in the circumferential direction of the expansion sleeve 4 by changing their shape in order to enable the widening of the expansion tabs 8 when expanding.

[0043] On an outer side of the expansion sleeve 4 facing away from the expansion body 3 and the anchor shaft 2, edges 22 are formed on the rear sides of the webs 20 facing away from the expansion body 3 at the transition from the openings 19 forming the webs 20 in the expansion tabs 8 to the outer sides of the expansion tabs 8 ( Figures 4 and 5). In the exemplary embodiment, the edges 22 have an edge angle of 90°, whereby the edge angle can in particular also be more acute and is preferably not more blunt. When the expansion tabs 8 are expanded in the anchor hole (not shown), the edges 22 on the rear sides of the webs 20 are pressed radially outward against the hole wall of the anchor hole by the expansion body 3 and are formed into the hole wall if the anchor base is not too hard. The edges 22 increase the hold of the expanded expansion sleeve 4 in the anchor hole and thereby improve the anchoring of the expansion anchor 1.

[0044] From the edges 22 on the rear sides of the webs 20, in the direction of the front end of the expansion sleeve 4, the outer sides of the webs 20 extend obliquely radially inwards, wherein an angle α between the outer sides and the axial direction of the expansion sleeve 4 is greater than half a cone angle of the expansion body 3, so that when the expansion tabs 8 are pivoted radially outwards during expansion, the edges 22 on the rear sides of the webs 20 rest against the hole wall of the anchor hole.

[0045] Preferably, the outer sides of the webs 20 extend diagonally inward directly from the edges 22 to obtain sharp, cutting-edge edges 22. For manufacturing reasons, the outer sides of the webs 20 in the exemplary embodiment extend a short distance axially parallel from the edges 22 before extending diagonally inward. A distance t between the edges 22 and the points from which the outer sides of the webs 20 extend diagonally inward is short and, in the exemplary embodiment, amounts to no more than 1.5 mm and preferably 1 mm or less.

[0046] On an inner side of the expansion sleeve 4 facing the expansion body 3, transitions from the inner side to the front edges 10 of the expansion tabs 8 and to the front sides of the webs 20 facing the expansion body 3 have curves R. The curves R are not manufacturing-related; the radii of the curves R are larger than the radii of manufacturing-related curves. A radius of the curves R is preferably 0.1 mm or larger. Instead of the curves R, chamfers, i.e., beveled surfaces, can also be provided at the transitions from the inner side of the expansion sleeve 4 to the front edges 10 of the expansion tabs 8 or to the front sides of the webs 20 (not shown). A chamfer angle of the chamfers to the longitudinal direction or axial direction of the expansion sleeve 4 is greater than half the cone angle of the expansion body 3.Both the curves R and the chamfers (not shown) avoid edges on the inside of the expansion sleeve 4 on the front edges 10 of the expansion tabs 8 and on the front sides of the webs 20, which could form into the expansion body 3 when the expansion body 3 is pulled in between the expansion tabs 8 to spread the expansion tabs 8 and hinder the pulling in of the expansion body 3 between the expansion tabs 8 and spreading of the expansion tabs 8.

[0047] When the expansion tabs 8 are spread in the anchor hole (not shown), the hole wall presses the connecting tabs 13 radially inwards so that the connecting tabs 13 enter the recesses 14 and the positive connections 16 are created. List of reference symbols

[0048] αAngle RRounding tDistance 1Expansion anchor 2Anchor shaft 3Expansion body 4Expansion sleeve 5External thread 6Abutment 7Longitudinal slot 8Expansion tab 9Expansion area 10Front edge 11Connecting web 12Connecting section 13Connecting tab 14Recess 15Expansion tab edge 16Form-fit connection 17Gap 18Turn and slide locking tab 19Opening 20Web 21Web section 22Edge

Claims

1. An expansion anchor having an expansion body (3) and an expansion sleeve (4), wherein the expansion sleeve (4) has an expansion region (9) in which expansion tabs (8) are formed by longitudinal slots (7), which tabs can be expanded by pulling in the expansion body (3) between the expansion tabs (8), and a connecting portion (12) which connects the expansion tabs (8), wherein an expansion tab (8) has a positive connection (16) with an adjacent expansion tab (8) or with the connecting portion (12) which connects the adjacent expansion tabs (8) or which connects an expansion tab (8) to the connecting portion (12) by a positive connection in a longitudinal direction of the expansion sleeve (4), wherein the connecting portion (12) is arranged at a rear end of the expansion tabs (8) remote from the expansion body (3), characterized in that the expansion tabs (8) are connected by connecting webs (11), which are narrower than the expansion tabs (8) in the circumferential direction of the expansion sleeve (4), to the connecting portion (12) of the expansion sleeve (4) which connects the expansion tabs (8) to one another via the connecting webs (11).

2. The expansion anchor according to claim 1, characterized in that the positive connection (16) has play in the longitudinal direction of the expansion sleeve (4).

3. The expansion anchor according to claim 1 or 2, characterized in that the positive connection (16) is formed by a connecting tab (13) which protrudes from a first expansion tab (8) in a circumferential direction of the expansion sleeve (4), and a recess (14) in an expansion tab edge (15) of an adjacent, second expansion tab (8) facing the first expansion tab (8) and / or in the connecting portion (12), wherein the connecting tab (13) engages in the recess (14).

4. The expansion anchor according to claim 3, characterized in that the recess (14) and / or the connecting tab (13) has / have edges running obliquely to the circumferential direction and the longitudinal direction of the expansion sleeve (4).

5. The expansion anchor according to claim 3 or 4, characterized in that the connecting tab (13) and / or the recess (14) has / have the shape of a rectangle arranged obliquely to the circumferential direction and to the longitudinal direction of the expansion sleeve (4).

6. The expansion anchor according to one or more of the preceding claims, characterized in that the connecting webs (11) are offset in the circumferential direction of the expansion sleeve (4) to the transverse centers of the expansion tabs (8).

7. The expansion anchor according to one or more of the preceding claims, characterized in that the connecting webs (11) in the circumferential direction of the expansion sleeve (4) are at most 0.8 times, in particular at most 0.33 times, and preferably at most 0.2 times as wide as the expansion tabs (8), and / or that a gap (17) between the connecting tabs (13) and the recesses (14) in a narrowest gap portion is at most 0.5 times as wide as a wall thickness of the expansion sleeve (4), and / or that the connecting tab (13) protrudes 1 / 4 to 1 / 3 of a width of the expansion tab (8) in the circumferential direction of the expansion sleeve (4) from the expansion tab (8).

8. The expansion anchor according to one or more of the preceding claims, characterized in that the expansion sleeve (4) has a rotation and sliding locking tab (18) which protrudes radially outward beyond a lateral surface of the expansion sleeve (4).

9. The expansion anchor according to one or more of the preceding claims, characterized in that the expansion tabs (8) have a web (20) which can be extended in a circumferential direction by a change in shape, in particular by a bend in the longitudinal direction of the expansion sleeve (4), so that the expansion tabs (8) can be widened in the circumferential direction when expanded.

10. The expansion anchor according to claim 9, characterized in that the expansion tabs (8) have a plurality of webs (20) offset from one another in the longitudinal direction of the expansion sleeve (4).

11. The expansion anchor according to claim 9 or 10, characterized in that the web (20) extends in the circumferential direction of the expansion sleeve (4) and has a bend and / or an angulation in the longitudinal direction of the expansion sleeve (4).

12. The expansion anchor according to one or more of the preceding claims, characterized in that the expansion tabs (8) have an opening (19) and an edge (22) at a transition of the opening (19) to an outer side of the expansion sleeve (4) facing away from the expansion body (3), and that the outside of the expansion sleeve (4) extends from the edge (22) or at a distance (t) in front of the edge (22) in the direction of the expansion body (3) obliquely inward in the direction of a longitudinal axis of the expansion sleeve (4).

13. The expansion anchor according to one or more of the preceding claims, characterized in that a transition from an inner side of the expansion sleeve (4) facing the expansion body (3) to a front edge (10) of the expansion sleeve (4) facing the expansion body (3), an expansion tab (8) of the expansion sleeve (4) or a web (20) of an expansion tab (8) of the expansion sleeve (4) has a chamfer or a fillet (R).

14. A method having an expansion anchor according to one or more of claims 3 to 13 for anchoring the expansion anchor in an anchor hole, characterized in that the connecting tab (13) of the positive connection (16) of the expansion tabs (8) forms the rotation and sliding locking tab (18) which projects radially outward beyond the lateral surface of the expansion sleeve (4) outside the anchor hole and which, when the expansion tabs (8) are expanded in the anchor hole, is pressed by a hole wall of the anchor hole into the recess (14) in the expansion tab edge (15) of the adjacent expansion tab (8).