Expansion anchor

Abstract

The invention relates to an expansion anchor (1) having a main body (2) made of plastics material. Two expansion elements (12) made of metal are arranged on the outside of the main body (2), extend in parallel with the longitudinal axis (3) and are mounted with their longitudinal ends (14, 15) in engagement openings (21, 22) in the main body. A width (24, 25) of the engagement openings (21, 22) measured in parallel with the longitudinal axis (3) is at most as large as twice the thickness of the longitudinal end (14, 15) engaging in the engagement opening (21, 22), measured in parallel with the longitudinal axis (3).

Description

[0001] FIW2961 07.02.2025

[0002] LD

[0003] Description

[0004] Expansion dowel

[0005] The invention relates to an expansion anchor having the features of the preamble of claim 1.

[0006] A generic expansion anchor is known from German patent application DE 102014 107719 A1. The known expansion anchor consists of a base body extending along a longitudinal axis. The base body is made of plastic and comprises an expansion section with a pointed tip at the front end of the expansion anchor and a sleeve body with a circumferential collar at the rear end. Within the expansion section, two parallel plastic expansion ribs extending along the longitudinal axis form the expansion elements. To improve holding power under heat and fire exposure, cylindrical steel expansion elements are arranged circumferentially between the two expansion ribs. These elements are supported at their lateral edges in grooves in the base body. The grooves extend along the lateral edges of the two expansion ribs and parallel to the longitudinal axis.Once the expansion anchor is inserted into a borehole, screwing in an expansion screw longitudinally into an expansion channel located centrally in the anchor body expands both the two plastic expansion webs and the two steel expansion elements. This means the expansion screw presses them radially outwards against the borehole wall. If the plastic melts under the influence of fire, at least the two steel plates remain in contact with the borehole wall, thus giving the expansion anchor residual load-bearing capacity even during and after the fire.

[0007] A disadvantage of the well-known expansion anchor is that it is only suitable for use in solid building materials such as concrete. If there is no stable borehole wall against which the expansion webs and elements rest and are pressed over a large portion of their length during expansion, the longitudinal edges of the steel plates can move out of the grooves and detach from the base body. The expansion screw then lacks counter-pressure and cannot gain purchase on the steel surfaces.

[0008] The object of the invention is therefore to create an expansion anchor that exhibits good expansion and load-bearing behavior in various building materials, even under fire exposure. This object is achieved according to the invention by an expansion anchor with the features of claim 1.

[0009] The expansion dowel according to the invention has a base body made of plastic and at least one expansion element made of metal.

[0010] The base body extends longitudinally along a longitudinal axis from a rear end (in the insertion direction) to a front end. The base body is, in particular, longer longitudinally than the spreading element. Specifically, the base body extends longitudinally beyond the spreading element at both ends, meaning that the base body extends further forward and / or further back than the spreading element.

[0011] "Front" and "back" refer to the insertion direction of the expansion anchor into a borehole. The "insertion direction" is the direction in which the expansion anchor is normally inserted into a borehole. Thus, the front end is the end of the expansion anchor that is at the front and, when the anchor is normally inserted, is the first end to enter the borehole. The rear end is therefore the end opposite the front end in the direction of the longitudinal axis. The insertion direction is regularly parallel to, or in the direction of, the longitudinal axis. The longitudinal axis runs straight through the anchor body, specifically through the center of the front and rear ends.

[0012] The ends of the base body form, in particular, the ends of the expansion anchor. The base body has, in particular, a tapered anchor tip at its front end and, in particular, a circumferential flange-like collar at its rear end. The base body is made of plastic, in particular as a single piece, especially using a one- or multi-component injection molding process. Due to the injection molding process, the base body has a homogeneous elastic structure, which contributes to good expansion and load-bearing properties. Furthermore, the expansion anchor can be manufactured cost-effectively and in large quantities using injection molding.

[0013] The expansion element is made of metal. It is preferably a sheet metal strip produced from a metal sheet, particularly as a bent part, especially as a stamped and bent part, which allows for very cost-effective manufacturing. The expansion element extends along its length parallel to the longitudinal axis. In particular, the expansion element is designed as a kind of elongated strip. The length of the strip is in particular at least three times, in particular at least five times, and in particular at least ten times its minimum width measured in the circumferential direction of the expansion anchor. In particular, the expansion element extends in the circumferential direction over a maximum of half, in particular over a maximum of one quarter, of the circumference of the expansion anchor.

[0014] The base body of the expansion anchor according to the invention comprises, in particular, in addition to the metal expansion element, an expansion body made of plastic, which is part of the base body and, like the expansion element, is arranged in an expansion area of ​​the expansion anchor. The expansion body is an element in the expansion area which, when an expansion screw is inserted or screwed into the expansion channel, is pushed outwards away from the longitudinal axis, thereby increasing the outer diameter of the expansion area, i.e., expanding it. The expansion body is, in particular, an expansion web extending parallel to the longitudinal axis, which is connected to the other parts of the base body, in particular to one or both of its longitudinal ends, and especially integrally.

[0015] The expansion element is arranged on the base body, in particular such that it forms part of the outer surface of the unexpanded expansion anchor. Specifically, the expansion element forms part of an outer surface of the expansion area of ​​the expansion anchor. In particular, the expansion element and the base body form an expansion channel extending along the longitudinal axis within the base body, so that a screw screwed into the expansion channel rests directly against the metal expansion element.

[0016] By additionally forming a plastic expansion body in combination with the metal expansion element, the expansion behavior of the expansion anchor can be very well adapted to different building materials, while the metal expansion element ensures the (residual) load-bearing capacity in case of fire.

[0017] According to the invention, the metal spreading element engages with at least one of its longitudinal ends in an engagement opening of the base body, so that the spreading element is supported in the base body at least with this longitudinal end. In particular, the longitudinal end is inserted into the engagement opening after the base body has been manufactured, or it is overmolded as an insert during the injection molding of the base body.

[0018] The expansion plug forms a fastening set with an expansion screw.

[0019] The longitudinal end, which serves to engage the opening, is a free end piece of the expansion element. This end piece is angled at a bend point, in particular from a longitudinal section of the expansion element running parallel to the longitudinal axis, and bent inwards towards the longitudinal axis with respect to the expansion plug. The longitudinal end thus projects inwards into the base body as a cantilever from the longitudinal section of the expansion element. The longitudinal end therefore deviates from the direction parallel to the longitudinal axis in which the longitudinal section runs. In particular, the end piece forms an angle of at least 45 degrees to 135 degrees with the longitudinal section, in particular 70 degrees to 110 degrees, and in particular substantially 90 degrees. In particular, the end piece runs radially to the longitudinal axis and / or in a radial plane to the longitudinal axis within the opening.The term "longitudinal end" here refers not only to the outermost point of the spreading element in the longitudinal direction, but to an area or section of the spreading element from the bending point to the free end.

[0020] According to the invention, the width of the engagement opening, measured parallel to the longitudinal axis, is at most twice, and in particular at most one and a half times, the thickness of the longitudinal end that engages in the engagement opening. In the case of a changing cross-section of the engagement opening, the "width" is the minimum width of the cross-section in which the longitudinal end lies. In particular, the width of the engagement opening is selected such that it forms a kind of clearance fit with the longitudinal end engaging in it, such that the longitudinal end is held stationary but pivotably movable within the engagement opening.

[0021] The design according to the invention ensures that the expansion element, while connected to the base body, can expand largely unhindered and independently of the base body, particularly independently of any expansion element, provided one is formed on the base body. The expansion behavior of the expansion element can thus be adapted to different building materials. For example, it can be designed to buckle or twist in a cavity, while maintaining its support in the base body. Furthermore, due to the metal expansion element, the expansion anchor according to the invention can retain residual load-bearing capacity even after exposure to fire.The inventive adjustment of the width of the engagement opening to the thickness of the longitudinal end also ensures that the spreading element is held securely in the base body, but can still be mounted easily and without great effort, in particular by inserting the longitudinal end into the engagement opening.

[0022] In possible embodiments of the expansion anchor according to the invention, the expansion element is supported in the base body exclusively at one of its longitudinal ends. However, in other embodiments of the expansion anchor according to the invention, it may be preferred that the at least one expansion element is supported in the base body at both of its longitudinal ends, i.e., at the front and rear of the expansion element. The choice of support depends on the intended use of the expansion anchor and the desired expansion behavior. For example, if supported at both ends, the expansion element can buckle outwards and / or form a node with one or more other expansion elements and / or one or more expansion bodies. For buckling to occur, the expansion element is specifically not supported in a central section of its longitudinal extent in such a way that outward movement is hindered.

[0023] By mounting the spreading element at at least one of its longitudinal ends, it is ensured that the spreading element can move independently of the base body, at least in partial regions of its length, when spreading. Preferably, the spreading element is mounted such that it is movable outwards, away from the longitudinal axis, relative to and independently of the base body and, in particular, also of any spreading body that may be present.

[0024] "Supported in the base body" means that the expanding element engages with the engagement opening at least at one of its longitudinal ends in such a way that it is fixed in the base body. The expanding element engages spatially with the base body. In particular, the longitudinal end penetrates the base body radially to its longitudinal axis. The longitudinal end is held in the engagement opening, in particular by a positive locking mechanism, to prevent unintentional movement out of the engagement opening. Depending on the type of support, the longitudinal end may have degrees of freedom in the engagement opening. In particular, the expanding element is held essentially axially fixed in the engagement opening with its longitudinal end. In particular, the expanding element is held essentially circumferentially fixed in the engagement opening with its longitudinal end. "Essentially fixed" here means that some play may exist between the longitudinal end and the engagement opening, but is not required.The spreading element can be clamped in the engagement opening with no play at its longitudinal end, so that the spreading element is bent at the transition from the longitudinal end to the adjoining longitudinal piece when moved radially away from the longitudinal axis.

[0025] According to the invention, the metal spreading element does not rest on the outer surface of the plastic base body with at least one of its longitudinal ends, but rather penetrates inwards into the base body, in particular by at least 20 percent, and in particular by at least 25 percent, of the diameter of the base body at the point of engagement. In particular, the front and / or rear end face of the spreading element lies within the base body and is, in particular, enclosed by the base body. For this purpose, the longitudinal end can be completely or partially surrounded by plastic, for example, overmolded with plastic. The spreading element can be used as an insert during the injection molding of the base body. Alternatively, the spreading element can be subsequently inserted into the spreading body, in particular by being plugged in or clipped into place.

[0026] The longitudinal section of the spreading element can touch any existing spreading body, lie flat against it, and / or detach from it and / or slide along it during spreading. The spreading element and the spreading body can also be connected by stretchable or detachable connectors, which serve as a kind of transport safety device, but do not, or only minimally, impede independent movement of the spreading element during spreading.

[0027] In particular, the expansion element is not covered by plastic over more than half its length on the outside, so that when expanded with an expansion screw, the screw comes into direct contact with the metal expansion element. Specifically, the longitudinal section of the expansion element running parallel to the longitudinal axis is completely uncovered by plastic on the outside and, more importantly, also completely uncovered on the inside, towards an expansion channel. This ensures that, in the event of a fire, the force is transferred from the borehole wall to the expansion element and from the expansion element directly to the expansion screw, thus maintaining its integrity.

[0028] If an expansion element and an expansion channel are formed in an expansion area of ​​the expansion anchor, the expansion element, together with the expansion element, can enclose the expansion channel, at least partially. In particular, the expansion channel is enclosed circumferentially by several expansion elements and / or several expansion bodies, whereby individual circumferential openings may be present between the expansion element(s) and the expansion body(s).

[0029] In a preferred embodiment of the expansion dowel according to the invention, the width of the engagement opening narrows inwards, i.e., from the radial outside towards the longitudinal axis. In particular, the engagement opening has an insertion chamfer on the outside in the region of the outer surface of the expansion dowel, for example, in the form of a wedge. This means that, in this embodiment, the engagement opening has a larger width radially outwards in the region of the outer surface than radially inwards, which facilitates the insertion of the longitudinal end but ensures a secure, captive hold of the longitudinal end, which is inserted into the engagement opening as intended.

[0030] It is further preferred that the longitudinal end engages a retaining element of the base body arranged in the engagement opening after the longitudinal end has been inserted into the base body as planned, such that the longitudinal end is positively locked in the engagement opening. The retaining element is, in particular, a rib, a spring, or a web. A retaining device can be provided at the longitudinal end, for example, in the form of a hook or groove, which corresponds to the retaining element. This design ensures a secure, positive-locking fit of the longitudinal end in the engagement opening.

[0031] To ensure a particularly secure fit of the longitudinal end in the engagement opening, the longitudinal end engages the cross-section of the base body to more than half its transverse diameter, in particular to at least two-thirds, and especially to at least three-quarters, of its transverse diameter. "Transverse diameter" refers to the extent of the base body in the direction in which the longitudinal end is inserted into the engagement opening.

[0032] The "direction of engagement" is the direction in which the respective longitudinal end is inserted into the corresponding opening. The direction of engagement forms a surface normal to a plane in which the longitudinal axis lies.

[0033] Preferably, the expansion anchor according to the invention comprises at least two metal expansion elements whose front and / or rear longitudinal ends are angled such that they engage in the same cross-section in engagement openings of the base body. The engagement openings have the same cross-section and, in particular, merge into one another, i.e., they occupy a common volume. "Angled" here refers to the longitudinal section of the respective expansion element extending parallel to the longitudinal axis. In particular, the two expansion elements are identical. In particular, the two expansion elements engage the base body on opposite sides. In particular, the two longitudinal sections run parallel.

[0034] The two longitudinal ends rest against each other, particularly along their facing inner surfaces. This allows the two longitudinal ends to be supported within the respective engagement openings, preventing unintentional movement of the longitudinal ends into or out of the engagement openings. Specifically, the longitudinal ends overlap in their respective engagement direction, and the inner surfaces rest against each other in the direction of engagement. Preferably, the inner surfaces have inclined surfaces that are inclined towards the respective engagement direction, particularly at an angle of 10 degrees to 45 degrees to the engagement direction. Preferably, the inner surfaces of the segments adjacent to the inclined surfaces have contact surfaces that run parallel to the respective engagement direction. And preferably, the two segments rest against each other at their inclined surfaces and their contact surfaces, thus achieving good support.In a further preferred embodiment of the expansion anchor according to the invention, the metal expansion element engages with its second longitudinal end in a further engagement opening in the base body, so that the second section is supported in the base body. The second longitudinal end and the further engagement opening are designed in particular like the first longitudinal end and the first engagement opening described above.

[0035] In particular, the further engagement opening forms a rear engagement opening and the engagement opening described above forms a front engagement opening, which are longitudinally offset from each other on the base body. In particular, the expansion anchor has at least two front and at least two rear engagement openings, in particular exactly two front and exactly two rear engagement openings, wherein the front and / or the rear engagement openings are in particular each located in a common radial plane to the longitudinal axis, i.e. in the same cross-section of the base body of the expansion anchor according to the invention.

[0036] The rear longitudinal end of a metal spreading element, and in the case of multiple spreading elements, preferably all rear longitudinal ends, are T-shaped, with the bar of the T forming the outer end of the longitudinal end that projects into the base body. The bar is particularly concave, bent inwards towards the longitudinal axis, so that its two ends form the outer ends of the longitudinal end. Furthermore, the rear longitudinal ends preferably engage the cross-section of the base body only up to a maximum of half its transverse diameter. This design allows for the simple formation of a spreading channel between the rear longitudinal ends of several spreading elements, enabling a screw for spreading to be moved forward through the spreading channel between the end faces of the rear longitudinal ends.

[0037] 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 are possible.

[0038] The invention is explained in more detail below with reference to an embodiment shown in the drawing. The drawing shows:

[0039] Figure 1 shows an expansion dowel according to the invention in a perspective view;

[0040] Figure 2 shows the expansion dowel according to the invention in a side view;

[0041] Figure 3 shows a front end of the expansion dowel according to the invention in a side view;

[0042] Figure 4 shows the front end of the expansion dowel according to the invention in a perspective sectional view, cut in plane IV-IV of Figure 3;

[0043] Figure 5 shows the front end of the expansion dowel according to the invention in a top view, cut in the plane VV of Figure 3;

[0044] Figure 6 shows the front end of the expansion dowel according to the invention in a radial section in the plane Vl-Vl of Figure 3;

[0045] Figure 7 shows a rear end of the expansion dowel according to the invention in a side view;

[0046] and

[0047] Figure 8 is a radial section through the rear end in the plane VIII-III of Figure 7 as a perspective representation.

[0048] The figures show an expansion anchor 1 according to the invention. The expansion anchor 1 has a base body 2 made of plastic, which extends along a longitudinal axis 3 from a rear end 4 of the base body 2 to a front end 5 of the base body 2. The front end 5 and the rear end 4 of the base body 2 also form the two ends of the expansion anchor 1. The base body 2 is manufactured in one piece from plastic by injection molding, here from a polyamide. At the front end 5, the base body 2 has a frustoconical anchor tip 6 for easier insertion into a borehole, while at the rear end 4 a circumferential collar 7 is formed, from which two anti-rotation ribs 8 extend forward.At the rear end 4, an opening for a screw (not shown) is formed, through which the screw can be screwed into an expansion channel 9 extending along the longitudinal axis 3 in the base body 2. Between its two ends 4, 5, the base body 2 has an expansion area 10 with two expansion bodies 11. The two expansion bodies 11 are opposite each other with respect to the longitudinal axis 3 and are separated from each other. The expansion channel 9 is arranged between the two expansion bodies 11. By inserting a screw into the expansion channel 9, the two expansion bodies 11 are pushed away from each other and radially outwards towards the longitudinal axis 3, thereby anchoring the expansion anchor 1 firmly in a borehole (not shown).

[0049] Two metal spreading elements 12 are arranged on the base body 2 in the spreading area 10. The spreading elements 12 are manufactured as sheet metal strips from a metal sheet by means of stamping and bending. The two spreading elements 12 are also positioned opposite each other with respect to the longitudinal axis 3. To accommodate the two spreading elements 12, slot-like, longitudinally extending recesses 13 are formed laterally on the base body 2 between the two spreading bodies 11. The two spreading elements 12 are inserted into the recesses 13. They thus lie circumferentially between the two spreading bodies 11 and extend parallel to the longitudinal axis 3. The spreading bodies 11 and the spreading elements 12 are essentially the same length. When a screw is inserted into the spreading channel 9, the spreading elements 12 are also spread outwards, away from each other.

[0050] To ensure optimal expansion and load-bearing behavior of the expansion anchor 1 in different building materials, the two expansion bodies 11 are integrally connected to the other parts of the base body 2 only at their longitudinal ends 16, 17. Similarly, the two expansion elements 12 are also connected to, or supported within, the base body 2 only at their longitudinal ends 14, 15.

[0051] The two spreading elements 12 are geometrically identical. They extend with a longitudinal section 18 parallel to the longitudinal axis 3 and each has a bending point 19, 20 at both ends of the longitudinal section 18, at which the respective longitudinal end 14, 15 is bent or angled inwards by 90 degrees towards the longitudinal axis 3. The two spreading elements 12 thus each have a first, front longitudinal end 14 and a second, rear longitudinal end 15, with which they engage in engagement openings 21, 22 formed in the base body 2 to receive the longitudinal ends 14, 15. The longitudinal ends 14, 15 engage in the base body 2 in the direction of an engagement direction 23, which in the exemplary embodiment runs perpendicular to the longitudinal axis 3, as shown by an arrow in Figures 6 and 8. In the exemplary embodiment, the two first, front engagement openings 21 lie in a cross-section, as do the two second, rear engagement openings 22.This also applies to the two first, front longitudinal ends 14 and to the two second, rear longitudinal ends 15.

[0052] The longitudinal ends 14, 15 are mounted in the engagement openings 21, 22. In this embodiment, they are fixed in position but with play, i.e., not rigidly clamped against bending. For this purpose, the minimum width 24 of the first, front engagement opening 21 and the minimum width 25 of the second, rear engagement opening 22, measured parallel to the longitudinal axis 3, are slightly larger than the thickness 35 of the longitudinal end 14, 15 engaging the respective engagement opening 21, 22, measured parallel to the longitudinal axis 3. In this embodiment, the thickness 35 corresponds to the sheet thickness of the stamped and bent part. As can be seen in Figures 3 and 7, the widths 24, 25 of the engagement openings 21, 22 are smaller in this embodiment than one and a half times the thickness 35 of the respective longitudinal end 14, 15.

[0053] The second, rear longitudinal ends 15 have a different geometric configuration than the first, front longitudinal ends 14 of the two spreading elements 12. As can be seen particularly in Figure 8, the second, rear longitudinal ends 15 are T-shaped, with the inner beams 26 of the Ts being concavely bent towards the longitudinal axis 3. The second, rear longitudinal ends 15 are positively engaged in the rear engagement openings 22. The beams 26 engage with their free ends walls of the base body 2 that adjoin the engagement openings 22 in the circumferential direction. In addition, the two beams 26 rest against inner ribs 27 of the base body 2, so that they are also fixedly supported in the circumferential direction.To insert the two second, rear longitudinal ends 15, the two second, rear engagement openings 22 are widened circumferentially in a V-shape outwards, so that the engagement openings 22 expand elastically when the beams 26 are inserted and the second, rear longitudinal ends 17 can be clipped into the second, rear engagement openings 22 in a form-fitting manner. Due to their concave shape, the two inner beams 26 do not close the expansion channel 9, but form a through-opening that is part of the expansion channel 9. A screw to be screwed into the expansion channel 9 can therefore pass between the two beams 26 without the two second, rear longitudinal ends 15 being moved outwards out of the second, rear engagement openings 22.

[0054] In contrast, the first, front longitudinal ends 14 and the first, front engagement openings 21 have a different geometry, as can be seen particularly in Figures 3 to 6. The width 24 of the first, front engagement openings 21, measured in the direction of the longitudinal axis 3, narrows from the outside to the inside towards the longitudinal axis 3, because the front boundary surfaces 28 of the first, front engagement openings 21 are each wedge-shaped, inclined from the outside front to the inside rear towards the longitudinal axis 3. This inwardly narrowing design of the first, front engagement openings 21 allows the first, front longitudinal ends 14 to be easily inserted into the respective first, front engagement opening 21. Nevertheless, the first, front longitudinal ends 14 are held securely and in a fixed position within the first, front engagement openings 21.

[0055] For a secure hold, a triangular rib is arranged as a retaining element 29 in each of the first, front engagement openings 21. Each rib engages in a groove 30 formed on the first, front longitudinal end 14 of the two spreading elements 12, as shown in Figure 6. This ensures that the first, front longitudinal ends 14 are positively locked in the first, front engagement openings 21. To achieve the most stable and secure fit possible, the first, front longitudinal ends 14 engage the cross-section of the base body 2 to more than half its transverse diameter, i.e., beyond a longitudinal plane 31 in which the longitudinal axis 3 lies and on which the respective engagement direction 23 forms a normal (see Figure 6). The two first, front longitudinal ends 14 overlap and abut each other on their facing inner surfaces 32.The inner surfaces 32 have inclined surfaces 33 that are inclined towards the direction of engagement 23. In addition, the inner surfaces 32 adjacent to the inclined surfaces 33 have contact surfaces 34 that run parallel to the respective direction of engagement 23. As can be seen in Figure 6, the two first, front longitudinal ends 14 support each other. This support ensures that the positive-locking connection between the retaining element 29 and the groove 30 is maintained even if the dowel is twisted or bent transversely to the longitudinal axis 3. This design securely holds the first, front longitudinal ends 14 in the first, front engagement openings 21.

[0056] The arrangement of the expansion elements 12 on the base body 2 according to the invention enables secure anchoring of the expansion anchor 1 in a borehole. The two metal expansion elements 12 also ensure that the expansion anchor 1 can transmit a holding force to the borehole wall even in the event of fire. The additional design of plastic expansion elements 11 in the expansion area 10 of the base body 2 allows the expansion behavior to be adapted to different anchoring substrates, making the expansion anchor 1 according to the invention suitable for a wide range of applications. FIW2961 07.02.2025

[0057] LD

[0058] List of reference signs

[0059] Expansion dowel

[0060] 1 expansion anchor

[0061] 2 basic shapes

[0062] 3 Longitudinal axis

[0063] 4 rear end of the base body 2

[0064] 5 front end of the base body 2

[0065] 6 dowel tips

[0066] 7 collars

[0067] 8 anti-rotation ribs

[0068] 9 Spreading channel

[0069] 10 Spreading range

[0070] 11 Spreader bodies

[0071] 12 Spreading element

[0072] 13. Further Study

[0073] 14 first, front longitudinal end of the spreading element 12

[0074] 15 second, rear longitudinal end of the spreading element 12

[0075] 16 front longitudinal end of the spreader body 11

[0076] 17 rear longitudinal end of the spreader body 11

[0077] 18 longitudinal pieces

[0078] 19 first, front bending point

[0079] 20 second, rear bending point

[0080] 21 first, front access opening

[0081] 22 second, rear access opening

[0082] 23 Direction of intervention

[0083] 24 Width of the first, front access opening 21

[0084] 25 Width of the second, rear access opening 22

[0085] 26 bars

[0086] 27 Inner rib

[0087] 28 front boundary surface of the first, front access opening 21

[0088] 29 Holding element

[0089] 30 Groove Longitudinal plane

[0090] Inner surface

[0091] inclined surface contact surface

[0092] Thickness of the spreading element 12

Claims

FIW2961 07.02.2025 LD Claims 1. Expansion dowel (1), with a base body (2) made of plastic, which extends from a rear end (4) along a longitudinal axis (3) to a front end (5), and with at least one spreading element (12) made of metal, which is arranged on the base body (2) and which extends in its length parallel to the longitudinal axis (3), characterized in that that the spreading element (12) made of metal engages with at least one of its longitudinal ends (14, 15) in an engagement opening (21, 22) of the base body, so that the spreading element (12) is supported in the base body (2) with this longitudinal end (14, 15), and that a width (24, 25) of the engagement opening (21, 22) measured parallel to the longitudinal axis (3) is at most as large as twice the thickness (35) of the longitudinal end (14, 15) engaging in the engagement opening (21, 22) measured parallel to the longitudinal axis (3).

2. Expansion dowel (1) according to claim 1, characterized in that the width (24) of the engagement opening narrows inwards.

3. Expansion dowel (1) according to one of claims 1 or 2, characterized in that the longitudinal end (14) engages behind a retaining element (29) of the base body (2) arranged in the engagement opening (21).

4. Expansion dowel (1) according to one of the preceding claims, characterized in that the expansion dowel (1) has at least two expansion elements (12) made of metal, the longitudinal ends (14, 15) of which are angled so that they engage in the same cross-section in engagement openings (21, 22) of the base body (2).

5. Expansion dowel (1) according to claim 4, characterized in that the two longitudinal ends (14) abut each other on mutually facing inner surfaces (32).

6. Expansion dowel (1) according to claim 4 or claim 5, characterized in that the inner surfaces (32) have inclined surfaces (33) which are inclined towards a direction of engagement (23) in which the longitudinal ends (14) engage in the engagement opening (21).

7. Expansion dowel (1) according to claim 6, characterized in that the inner surfaces (32) of the longitudinal ends (14) have contact surfaces (34) adjacent to the inclined surfaces (33) which run parallel to the respective direction of engagement (23).

8. Expansion dowel (1) according to one of the preceding claims, characterized in that the expansion element (12) made of metal engages with its second longitudinal end (15) in a further engagement opening (22) in the base body (2), so that the second longitudinal end (15) is supported in the base body.

9. Expansion dowel (1) according to one of claims 1 to 8, characterized in that one of the longitudinal ends (14) engages in the cross-section of the base body (2) to more than half the transverse diameter of the base body (2).

10. Expansion dowel (1) according to one of claims 1 to 9, characterized in that one of the longitudinal ends (15) is T-shaped and in particular engages in the cross-section of the base body (2) up to a maximum of half the transverse diameter of the base body (2).

11. Expansion dowel (1) according to one of claims 1 to 10, characterized in that the expansion element (12) is a sheet metal strip made from a metal sheet.

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