DOWEL

Description

[0001] The invention relates to a dowel having the features of the preamble of claim 1.

[0002] From the patent application DE 37 32 596 A1, a dowel is known which is divided by a longitudinal slot in an axial plane over most of its length into two spreading legs which are connected to each other at, for example, three points in a longitudinal direction of the dowel by tabs on the circumference.

[0003] The object of the invention is to propose a dowel that exhibits good holding values ​​in different anchoring substrates.

[0004] This problem is solved according to the invention by a dowel having the features of claim 1.

[0005] The anchor according to the invention has two anchor sections extending longitudinally along the anchor and arranged one behind the other. An "anchor section" is a section of the anchor designed for anchoring the anchor in an anchor hole in the anchor base. The anchor hole is, in particular, a borehole in masonry or a concrete component. A front anchor section is located longitudinally in front of a rear anchor section, with "in front" referring to the intended insertion direction of the anchor into an anchor hole in the anchor base. The front anchor section thus enters the anchor hole before the rear anchor section can enter the anchor hole.

[0006] The two anchor sections are directly adjacent to each other. Together they form an expansion area of ​​the anchor, which constitutes a front end section of the anchor. The rear anchor section has at least two rear expansion legs extending longitudinally across the rear anchor section, which are opposite each other, particularly with respect to a longitudinal axis of the expansion anchor, and which are connected to each other at their longitudinal ends. The length of the rear expansion legs is greater in the longitudinal direction than the diameter of the rear anchor section.

[0007] In particular, the front anchor section also has at least two front expansion legs extending longitudinally across the rear anchor section, which are opposite each other, especially with respect to the longitudinal axis of the expansion anchor, and which are connected to each other at their longitudinal ends. The length of the front expansion legs is greater in the longitudinal direction than the diameter of the front anchor section.

[0008] In particular, the rear spreader legs and the front spreader legs touch. Specifically, the front longitudinal ends of the rear spreader legs merge into the rear longitudinal ends of the front spreader legs, these longitudinal ends being connected, in particular, by a connector.

[0009] Transversely, and especially radially to the longitudinal direction, the two anchor sections are elastic enough that when inserted into a cylindrical anchor hole whose diameter is smaller than one or the diameters of the anchor sections before insertion, they are elastically compressed and bear against the wall of the anchor hole with an elastic contact force. The anchor sections need not have circular cross-sections, but can also have elliptical or elliptical-like cross-sections, i.e., cross-sections with different dimensions in different directions. Therefore, "diameter of the anchor sections" refers to the diameter of a circumscribed circle enclosing one of the anchor sections. This imaginary circumscribed circle rests, for example, on two opposite points or on three or four points around the circumference of one of the two anchor sections.By inserting a pin-shaped expansion element into the anchor sections, these can also be expanded, i.e., radially widened, to increase the anchor force, i.e., the hold of the anchor against being pulled out of the anchor hole. The expansion element is, for example, a screw or a nail. The expansion element is not essential for the invention.

[0010] In an unspread state and before insertion into the anchor hole, the diameter of the front anchor section, and preferably also the rear anchor section, increases from its longitudinal ends towards a longitudinal center. That is, in a longitudinal central region of the anchor sections, the front and preferably also the rear anchor section has a larger diameter than at the longitudinal ends of the anchor sections.

[0011] According to the invention, in a cylindrical anchor hole whose diameter is smaller than the diameters of the anchor sections of the anchor before insertion into the anchor hole, the radial contact force against the hole wall of the rear anchor section of the anchor is greater than that of the front anchor section. Typically, the anchor hole has a nominal diameter equal to that of the anchor, and the anchor sections of the anchor can be compressed to this nominal diameter for insertion into the anchor hole. The greater radial contact force against the hole wall of the cylindrical anchor hole can be achieved by a larger diameter of the rear anchor section compared to the front anchor section before insertion into the anchor hole, and / or by greater radial stiffness of the rear anchor section, and / or by a shorter rear anchor section than front anchor section of the anchor according to the invention.This means that, according to the invention, the spring stiffness in the transverse direction, i.e., in the direction in which the hole wall acts on the anchor sections, is smaller when the front anchor section is compressed to the diameter of the anchor hole than that of the rear section when it is compressed in the transverse direction to the diameter of the anchor hole. As described, the diameters of the anchor sections are the diameters of their circumscribed circles; that is, the rear anchor section can, for example, have a larger transverse dimension in the direction perpendicular to the longitudinal direction of the anchor, in which the anchor section is compressed when inserted into the cylindrical anchor hole, than the front anchor section. The invention does not preclude other possibilities for the greater radial contact force of the rear anchor section.Therefore, the insertion force into an anchor hole and, conversely, the pull-out force from the anchor hole of the rear anchor section of the anchor according to the invention are greater than that of its front anchor section. The radial contact force and the insertion force refer to the anchor sections not expanded by an expansion element, although expansion with an expansion element is not excluded. However, an expansion element changes the radial contact force and the anchor force and can also reverse their ratio between the front and rear anchor sections.

[0012] An advantage of the anchor according to the invention is that its front anchor section can be inserted into a narrow anchor hole in a solid substrate such as concrete or solid masonry with a lower insertion force compared to the rear anchor section. In this case, the anchor can be anchored with sufficient anchoring force using only its front anchor section. In a wide anchor hole, as is typical for hollow building materials such as perforated bricks, or in a relatively soft substrate such as aerated concrete, where drilling results in anchor holes with a relatively large diameter compared to solid building materials due to the lower resistance the substrate offers the drill bit, or in a substrate where a drilled anchor hole exhibits spalling and thus widening, and / or in a substrate containing cavities, the anchor according to the invention achieves good anchoring force by anchoring with both of its anchor sections.

[0013] The dependent claims relate to advantageous embodiments and further developments of the invention specified in claim 1.

[0014] In a preferred embodiment of the invention, the front anchor section has at least two front expansion legs extending longitudinally along the anchor and elastic transversely to the anchor's longitudinal direction, and the rear anchor section has at least two rear expansion legs extending longitudinally along the anchor's longitudinal direction and elastic transversely to the anchor's longitudinal direction, wherein the rear expansion legs have a greater bending stiffness transversely to the anchor's longitudinal direction than the front expansion legs and / or the rear expansion legs project beyond the front expansion legs transversely to the anchor's longitudinal direction. The rear expansion legs are designed such that, due to their greater bending stiffness, they exert a greater radial outward clamping force than the front expansion legs when the front and rear expansion legs are compressed radially to a specific, equal degree.In particular, the spring stiffness of the rear spreader legs is correspondingly greater than that of the front spreader legs. "Protruding transversely to the longitudinal direction" means that the diameter of the circumscribed circle of the rear spreader legs is larger than the diameter of the circumscribed circle of the front spreader legs. Both the greater bending stiffness and the transverse projection result in a greater radial contact force of the rear spreader legs, or the rear anchor section, in the cylindrical anchor hole than of the front spreader legs, or the front anchor section.

[0015] In particular, the expansion legs are curved in the longitudinal direction of the anchor, especially convexly outwards, such that in their longitudinal central regions they protrude most outwards transversely to the longitudinal direction of the anchor. The expansion legs exhibit this curvature in their undeformed state, i.e., neither when compressed in the anchor hole nor when expanded by inserting the expansion element. In the deformed state, the expansion legs need not be convexly curved. The convex curvature affects an outer surface or an outer circumferential surface of the expansion legs.

[0016] Preferably, the front and / or rear spreading legs are supported at their longitudinal ends, which also form the longitudinal ends of the anchor sections, perpendicular to the longitudinal direction. This means that the longitudinal ends of the spreading legs are supported against each other to prevent compression during insertion into the anchor hole. This does not prevent the spreading legs from being compressed to the diameter of the anchor hole, but it does increase the radial contact force of the spreading legs against the wall of the anchor hole and thus the anchor force.

[0017] In the longitudinal direction of the dowel, the front and / or rear expanding legs are preferably continuously separated from each other in the longitudinal central area between their front and rear longitudinal ends in order not to make spreading, i.e. a radial pushing apart of the expanding legs, more difficult.

[0018] In a preferred embodiment of the invention, a front expansion leg is rigidly connected to a rear expansion leg such that the front and rear expansion legs form a kind of seesaw: When the front expansion leg is pressed inwards transversely to the longitudinal direction of the anchor, it exerts an outward force on the rear expansion leg transversely to the longitudinal direction of the anchor, and vice versa. In this way, the expansion legs alternately increase their contact force radially outwards when inserted into the anchor hole. "Rigidly" means a stiffness such that the described seesaw function results, in which pressing the front expansion leg inwards exerts an outward force on the rear expansion leg, and vice versa.

[0019] In particular, a front and a rear spreader leg merge seamlessly at a connection point, forming a connector. This means they are rigidly connected by means of the connector. This allows the bending moment to be transferred between two longitudinally arranged spreader legs, extending along a longitudinal axis and merging into one another, via the connector, so that the two spreader legs act statically like a continuous beam. Specifically, the connector forms a kind of material thickening, giving it a higher bending stiffness at the connection point than the spreader legs between their longitudinal ends.

[0020] In a preferred embodiment of the invention, a rear longitudinal end of the front expansion leg and a front longitudinal end of the rear expansion leg are supported transversely to the longitudinal direction of the dowel inwards. Thus, pressing the front expansion leg inwards transversely to the longitudinal direction of the dowel exerts an inward force on the rear expansion leg transversely to the longitudinal direction of the dowel outwards, and vice versa, particularly in the manner of a continuous beam, thereby mutually increasing the contact force of the expansion legs radially outwards.

[0021] Preferably, the rear longitudinal ends of the front spreading legs and / or the front longitudinal ends of the rear spreading legs are connected to each other in such a way that the resistance to being pushed apart transversely to the longitudinal direction of the dowel is increased at the rear longitudinal ends of the front spreading legs and / or at the front longitudinal ends of the rear spreading legs.

[0022] A connection of the rear longitudinal ends of the front spreader legs and / or the front longitudinal ends of the rear spreader legs transversely to the longitudinal direction of the dowel preferably also forms a support bearing that supports the rear longitudinal ends of the front spreader legs and the front longitudinal ends of the rear spreader legs transversely to the longitudinal direction of the dowel inwards in order to ensure the rocking function of the front and rear spreader legs.

[0023] One embodiment of the invention provides that the front anchor section has exactly two front expansion legs opposite each other with respect to the longitudinal axis of the anchor, and / or the rear anchor section has exactly two rear expansion legs opposite each other with respect to the longitudinal axis of the anchor. To expand the anchor, the anchor sections, or the expansion legs, an expansion element can be inserted between the expansion legs in the longitudinal direction of the anchor. "Expanding" means pushing the expansion legs apart transversely to the longitudinal direction of the anchor. The expansion element is, in particular, pin-shaped and, for example, a screw or a nail.

[0024] One embodiment of the anchor according to the invention provides a shaft extending in the longitudinal direction of the anchor, in particular a hollow shaft, especially in the form of a cylindrical tube with a closed outer surface, at a rear longitudinal end of the rear anchor section, which is furthest from the front anchor section. The anchor can thus be used, for example, as an insulation anchor, in which the shaft penetrates an insulating material on the anchor base, or as a frame anchor, in which the shaft bridges a gap between the anchor base and an attachment or the like. The shaft can be an integral part of the anchor or a separate component.

[0025] Preferably, the anchor has an axial abutment projecting transversely to the longitudinal direction beyond the longitudinal ends of the anchor sections or the expansion legs, either at or behind the rear longitudinal end of the rear anchor section. This abutment limits the common insertion depth of both anchor sections into the anchor hole.

[0026] 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 figure description and / or drawn in a figure, are not only usable in the combinations specified or drawn, but also in any other combination or individually. Embodiments of the invention are possible that 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 that do not have all the features of the exemplary embodiment, but rather any part of the characterized features of the exemplary embodiment, are also possible.

[0027] The invention is explained in more detail below with reference to an embodiment illustrated in the drawing. The drawing shows: Figure 1 is a side view of a dowel according to the invention; Figure 2 is a magnification of anchor sections of the dowel made of Figure 1 ; and Figure 3, an end view of the dowel according to arrow III in Figure 2 .

[0028] The dowel 1 according to the invention, as shown in the drawing, is designed as an insulation dowel and has a straight, tubular hollow shaft 2 with a retaining plate 3 at a rear end and two anchor sections 4, 5 arranged one behind the other in a longitudinal direction L of the dowel 1 at a front end of the hollow shaft 2. The "rear end" of the hollow shaft 2 is here referred to as the end at which the retaining plate 3 is arranged. The "front end" is the end of the hollow shaft 2 at which the anchor sections 4, 5 are arranged as the expansion area of ​​the dowel 1.

[0029] The two anchor sections 4, 5, the hollow shaft 2, and the retaining plate 3 can be integrally formed or assembled as separate parts. Preferably, the two anchor sections 4, 5, or their expanding legs 6, 7 (to be explained later), are integrally formed. In particular, the anchor sections are manufactured together as an injection-molded plastic part.

[0030] The retaining plate 3 is – in the exemplary embodiment – ​​a circular disc with openings 11, serving as a large-area support for holding an insulation panel (not shown). Neither the retaining plate 3 nor the hollow shaft 2 are essential components of the dowel 1; in embodiments of the invention, they may be omitted or replaced by other elements.

[0031] Both anchor sections 4, 5 each have two expansion legs 6, 7 opposite each other with respect to an axial plane 12 of the anchor 1. Here, the expansion legs 6 of the front anchor section 4 are referred to as the front expansion legs 6 and the expansion legs 7 of the rear anchor section 5 as the rear expansion legs 7. The anchor section 4 furthest from the hollow shaft 2 is referred to here as the front anchor section 4, and the anchor section 5 closest to and connected with the hollow shaft 2 is referred to as the rear anchor section 5. The number of two front expansion legs 6 and two rear expansion legs 7 is preferred, but not essential for the invention. Embodiments of the anchor 1 according to the invention are also possible, in particular with more than two front expansion legs 6 and / or more than two rear expansion legs 7.

[0032] In the longitudinal direction L of the dowel 1, the opposing front expansion legs 6 and likewise the opposing rear expansion legs 7 are curved outwards in an arc such that the front and rear expansion legs 6, 7 protrude further radially outwards from the axial plane 12 or from a longitudinal axis 13 of the dowel 1 at their longitudinal centers 18, 19 than at their longitudinal ends 14, 15, 16, 17. The rear longitudinal ends 15 of the front expansion legs 6 face the front longitudinal ends 16 of the rear expansion legs 7, the rear longitudinal ends 17 of the rear expansion legs 7 face the hollow shaft 2, and the front longitudinal ends 14 of the front expansion legs 6 face away from the hollow shaft 2 and the rear expansion legs 7. The longitudinal ends 14, 15, 16, 17 of the spreader legs 6, 7 also form the longitudinal ends 14, 15, 16, 17 of the corresponding anchor sections 4, 5.

[0033] Due to the outward curvature of their spreading legs 6, 7 in the longitudinal direction L of the dowel 1, the anchor sections 4, 5 of the dowel 1, in their undeformed state, have a larger diameter at their longitudinal centers 18, 19 or in longitudinal center sections between the longitudinal ends 14, 15, 16, 17 than at the longitudinal ends 14, 15, 16, 17. The diameter of the anchor sections 4, 5 is defined here as a diameter of a circumcircle 20 (see Figure 3 ) understood as, for example, lying against the spreading legs 6, 7 at two opposite circumferential points or at three, four or more circumferential points distributed evenly or unevenly over the circumference, and over which the spreading legs 6, 7 do not project outwards.

[0034] The expansion legs 6, 7 do not need to have circular circumferential surfaces and, in the exemplary embodiment, have elliptical circumferential surfaces. In the exemplary embodiment, the expansion legs 6, 7, or the anchor sections 4, 5, have a larger dimension radial to the longitudinal axis 13 of the dowel 1 in an expansion direction than perpendicular to the expansion direction.

[0035] Transverse to the longitudinal direction L of the anchor 1, that is, perpendicular to the axial plane 12 of the anchor 1, with respect to which the expansion legs 6, 7 are arranged opposite each other, or radially to the longitudinal axis 13 of the anchor 1, the expansion legs 6, 7 are elastic, which does not preclude elasticity in another direction. When the anchor sections 4, 5 are inserted into a cylindrical anchor hole (not shown), the diameter of which is smaller than the diameters of the anchor sections 4, 5, that is, smaller than the diameters of the circumcircles 20 of the anchor sections 4, 5, the expansion legs 6, 7 are elastically compressed to the diameter of the anchor hole such that they press against a wall of the anchor hole with a compressive force radial to the longitudinal axis 13 of the anchor 1. This occurs without an expansion element being inserted between the expansion legs 6, 7.According to the invention, the radial contact force of the rear expanding legs 7 against the wall of the anchor hole is greater than the radial contact force of the front expanding legs 6 against the wall of the anchor hole, which has the same diameter as the rear expanding legs 7. Therefore, the rear anchor section 5 exhibits both greater insertion resistance when inserted into the anchor hole and greater resistance to withdrawal from the anchor hole than the front anchor section. The insertion resistance and resistance of each anchor section 4, 5 are described separately.

[0036] In other words, the force required to radially compress the spreader legs 6, 7 to a certain degree is greater for the posterior spreader legs 7 than for the anterior spreader legs 6.

[0037] The greater radial contact force against the wall of the cylindrical anchor hole, and thus the greater insertion resistance and greater anchor force, are achieved through various measures: Firstly, the rear anchor section 5 is shorter in the longitudinal direction of the dowel 1 than the front anchor section 4, meaning that the rear, arc-shaped expanding legs 7, curved outwards in the longitudinal direction L, are stiffer against elastic deformation by a certain amount radially inwards than the front expanding legs 6.

[0038] Furthermore, the rear anchor section 5 has a larger diameter than the front anchor section 4, meaning that opposite circumferential points in the expansion direction of the rear expansion legs 7 are further away from the axial plane 12 or from the longitudinal axis 13 of the anchor 1 than opposite circumferential points of the front expansion legs 6. In the longitudinal direction L of the anchor 1, the rear expansion legs 7 project radially beyond the front expansion legs 6 in the expansion direction.

[0039] The measures described, which ensure that the rear spreading legs 7 exert a greater radial contact force against the wall of the cylindrical anchor hole, can be implemented individually or in any combination and sub-combination. The invention also does not preclude the use of other, unmentioned measures, either additionally or exclusively instead of the measures described.

[0040] At their front and rear longitudinal ends 14, 15, 16, 17, the front expansion legs 6 and the rear expansion legs 7 are connected to each other in such a way that they support each other radially inwards and are held against moving apart when inserted into an anchor hole. The connectors 8 at the rear longitudinal ends 15 of the front expansion legs 6 and the front longitudinal ends 16 of the rear expansion legs 7, and the connectors 8 at the rear longitudinal ends 17 of the rear expansion legs 7 are located in a circumferential region of the anchor 1, so that a pin-shaped expansion element (not shown), such as a screw or a nail, can be inserted from behind through the hollow shaft 2 between the rear and front expansion legs 7, 6 for spreading, i.e., for pushing the expansion legs 6, 7 apart in the direction of the longitudinal axis 13 of the anchor 1.

[0041] Between the connectors 8, the spreading legs 6, 7 are continuously separated from each other in the longitudinal direction of the dowel 1 in order not to impede movement of the spreading legs 6, 7.

[0042] The front spreader legs 6 and the rear spreader legs 7 are rigidly connected by the connectors 8 at their rear longitudinal ends 15 and 16, respectively. A front spreader leg 6 and a spreader leg 7 located longitudinally L behind it thus act statically as a continuous beam, for which the connectors 8 provide supports. Each front spreader leg 6 is rigidly connected to a rear spreader leg 7 located on the same side of the axial plane 12 or longitudinal axis 13 of the dowel 1. Due to their elasticity, the front spreader legs 6 do not transition rigidly into the rear spreader legs 7, but are rigid enough that radial compression of the front spreader legs 6 causes the rear spreader legs 7 to expand, and vice versa.The connectors 8 at the rear longitudinal ends 15 of the front expansion legs 6 and the front longitudinal ends 16 of the rear expansion legs 7 act as support bearings, supporting the expansion legs 6, 7 radially inwards via these bearings. This allows the front expansion leg 6, 7 and the rear expansion leg 6, 7, which transitions rigidly into it, to form a kind of rocker that can pivot around the connectors 8, which form the support bearings. The alternating radial outward force exerted on the expansion legs 6, 7 when the other expansion leg 6, 7 is pressed radially inwards increases the contact force and the anchoring force of the dowel 1 in an anchor hole.

[0043] Due to the lower insertion force of the front anchor section 4 into an anchor hole in a solid anchor base, for example, a concrete anchor base, the front anchor section 4 can be inserted into the anchor hole relatively easily. In a solid anchor base, anchoring with only the front anchor section 4 is usually sufficient. The rear anchor section 5 is preferably inserted only into an anchor hole in a less solid anchor base or in an anchor base containing cavities. The anchor force can be further increased by inserting the pin-shaped expansion element (not shown) between the expansion legs 6, 7, as it spreads the expansion legs 6, 7, i.e., pushes them radially apart, and thus exerts greater pressure against the wall of the anchor hole.

[0044] At its front longitudinal end, that is, at or shortly behind the rear longitudinal end 17 of the rear anchor section 5, the hollow shaft 2, or more generally the anchor 1, has one or more axial abutments 9 projecting radially in the longitudinal direction L of the anchor 1 beyond the front and / or rear longitudinal ends 14, 15, 16, 17 of the anchor sections 4, 5, which limit the insertion depth of the two anchor sections 4, 5 into the anchor hole in the anchor base. In the exemplary embodiment, the anchor 1 has two axial abutments 9 opposite each other, which are designed as radially projecting ribs.

[0045] To increase the anchor force in the anchor hole, the spreading legs 6, 7 have outer ribs 10 which extend in the circumferential direction and which are directed obliquely outwards / backwards as barbs in the longitudinal direction L of the dowel 1. Reference symbol list

[0046] Longitudinal direction 1 Dowel 2 Hollow shaft 3 Retaining plate 4 Front anchor section 5 Rear anchor section 6 Front expansion leg 7 Rear expansion leg 8 Connector 9 Axial abutment 10 Rib 11 Opening 12 Axial plane 13 Longitudinal axis 14 Front longitudinal end of the front expansion leg 6 or of the front anchor section 4 15 Rear longitudinal end of the front expansion leg 6 or of the front anchor section 4 16 Front longitudinal end of the rear expansion leg 7 or of the rear anchor section 5 17 Rear longitudinal end of the rear expansion leg 7 or of the front anchor section 5 18 Longitudinal center of the front expansion leg 6 19 Longitudinal center of the rear expansion leg 7 20 Circumference

Claims

1. Anchor (1), comprising a front anchoring section (4), which extends in a longitudinal direction (L) of the anchor (1), is elastic transversely to the longitudinal direction (L), and the diameter of which, in an unexpanded state, increases from its longitudinal ends (14, 15) towards its longitudinal middle (18), characterized in that the anchor (1) has a rear anchoring section (5), which extends in the longitudinal direction (L) of the anchor (1), is elastic transversely to the longitudinal direction (L), and has at least two rear expansion legs (7) extending in the longitudinal direction (L) over the rear anchoring section (5), which are connected to one another at their longitudinal ends and the length of which in the longitudinal direction (L) is greater than a diameter of the rear anchoring section (5), and which is located in the longitudinal direction (L) of the anchor (1) behind the front anchoring section (4), and in that, in a cylindrical anchor hole, the rear anchoring section (5) has a greater radial contact pressure force against a hole wall of the anchor hole than the front anchoring section (4).

2. Anchor (1) according to claim 1, characterized in that a diameter of the rear anchoring section (5), in an unexpanded state, increases from its longitudinal ends (16, 17) towards its longitudinal middle (19).

3. Anchor (1) according to claim 1 or 2, characterized in that the rear anchoring section (5) is shorter in the longitudinal direction (L) of the anchor (1) than the front anchoring section (4).

4. Anchor (1) according to one or more of claims 1 to 3, characterized in that the rear anchoring section (5) has a greater diameter than the front anchoring section (4).

5. Anchor (1) according to claim 1 or 2, characterized in that the front anchoring section (4) has at least two front expansion legs (6), extending in the longitudinal direction (L) of the anchor (1) and elastic transversely to the longitudinal direction (L), that the rear expansion legs (7) are elastic transversely to the longitudinal direction (L), and that the rear expansion legs (7) have a greater flexural rigidity transversely to the longitudinal direction (L) of the anchor (1) than the front expansion legs (6) and / or that the rear expansion legs (7) project beyond the front expansion legs (6) transversely to the longitudinal direction (L) of the anchor (1).

6. Anchor (1) according to claim 5, characterized in that the expansion legs (6, 7) are curved in the longitudinal direction (L) of the anchor (1).

7. Anchor (1) according to claim 5 or 6, characterized in that the front expansion legs (6) support one another at their longitudinal ends (14, 15) transversely to the longitudinal direction (L) of the anchor (1) and / or that the rear expansion legs (7) support one another at their longitudinal ends (16, 17) transversely to the longitudinal direction (L) of the anchor (1).

8. Anchor (1) according to one or more of claims 5 to 7, characterized in that the front expansion legs (6) and / or the rear expansion legs (7) are continuously separated from one another between their longitudinal ends (14, 15, 16, 17) in the longitudinal direction (L) of the anchor (1).

9. Anchor (1) according to one or more of claims 5 to 8, characterized in that a front expansion leg (6) is connected in a flexurally rigid manner to a rear expansion leg (7).

10. Anchor (1) according to one or more of claims 5 to 9, characterized in that a rear longitudinal end (15) of the front expansion leg (6) and a front longitudinal end (16) of the rear expansion leg (7) support one another inwardly in the manner of a support bearing transversely to the longitudinal direction (L) of the anchor (1), such that a force exerted inwardly transversely to the longitudinal direction (L) of the anchor (1) on the front expansion leg (6) loads the rear expansion leg (7) outwardly transversely to the longitudinal direction (L) of the anchor (1), and vice versa.

11. Anchor (1) according to one or more of claims 5 to 10, characterized in that expansion legs (6, 7) which are opposite one another with respect to a longitudinal axis (13) of the anchor (1) are connected to one another at a transition from the front anchoring section (4) to the rear anchoring section (5).

12. Anchor (1) according to claims 10 and 11, characterized in that the connection of the longitudinal ends (14, 15, 16, 17) of the expansion legs (6, 7) simultaneously forms a support bearing.

13. Anchor (1) according to one or more of the preceding claims, characterized in that the front anchoring section (4) has two opposite front expansion legs (6), between which an expansion element can be inserted for expanding the front expansion legs (6), and / or that the rear anchoring section (5) has two opposite rear expansion legs (7), between which the expansion element can be inserted for expanding the rear expansion legs (7).

14. Anchor (1) according to one or more of the preceding claims, characterized in that the anchor (1) has a shank, in particular a hollow shank (2), at the rear longitudinal end (17) of the rear anchoring section (5), which is remote from the front anchoring section (4) in the longitudinal direction (L) of the anchor (1).

15. Anchor (1) according to one or more of the preceding claims, characterized in that the anchor (1) has an axial abutment (9), projecting transversely to the longitudinal direction (L) of the anchor (1) beyond the front and / or rear longitudinal ends (14, 15, 16, 17) of the front and / or rear anchoring sections (4, 5), at or behind the rear longitudinal end (17) of the rear anchoring section (5), which is remote from the front anchoring section (4) in the longitudinal direction (L) of the anchor (1).