WO2014075776A1

WO2014075776A1 - Expansion anchor

Info

Publication number: WO2014075776A1
Application number: PCT/EP2013/003339
Authority: WO
Inventors: Harald Schädler
Original assignee: Fischerwerke Gmbh & Co. Kg
Priority date: 2012-11-14
Filing date: 2013-11-07
Publication date: 2014-05-22
Also published as: DE102013112233A1; CN104956098A; EP2926017A1

Abstract

The invention relates to an expansion anchor (101) having at least two primary expansion tongues (102), which extend in the longitudinal direction of the expansion anchor (101) and which engage at least partly around an expansion channel (107). The primary expansion tongues (102) can be moved radially outward and away from each other from a non-expanded state into an expanded state by means of an expansion element (108) that can be introduced into the expansion channel (107). The expansion anchor (101) additionally comprises at least one secondary expansion tongue (110), which is arranged between the primary expansion tongues (102). In order to devise an expansion anchor (101) by means of which a high retaining force can be transmitted even in soft, porous structural materials, according to the invention the secondary expansion tongue (110) is movable in the radial direction in such a way that, in an expanded state, the secondary expansion tongue (110) substantially completely fills an opening (109), present between the primary expansion tongues (102), in the circumferential surface (103) of the expansion anchor (101).

Description

description

expansion anchor

The invention relates to an expansion anchor with the features of the preamble of claim 1.

From the published patent application DE 198 49 821 A1 an expansion anchor is known, which has two expansion tongues, which extend in the longitudinal direction and are separated by a slot. The two expansion tongues are arranged in a spread region of the expansion anchor and surround a spreading channel into which a spreading element, for example a screw or a nail, can be introduced. When introducing the expansion element, the two expansion tongues are moved away from each other in the radial direction and the expansion region is spread open, whereby the expansion anchor can be anchored in a borehole in an anchoring ground. So that the expansion anchor also finds a firm hold in a porous anchoring base, the expansion anchor has two further expansion tongues in the expansion area, which are offset in the longitudinal direction from the first two expansion tongues and rotated 90 degrees relative to the first expansion tongues about the longitudinal axis, so that the expansion area spread in two mutually orthogonal planes.

A generic expansion anchor shows the European patent application EP 0 834 659 A1. The expansion anchor has a spreading region with two primary expansion tongues, which extend in the longitudinal direction of the expansion anchor and which are connected at their insertion side front and rear ends by sleeve-shaped sections. Between the two primary spreaders there are two secondary spreader tongues separated by slits from the primary spreader tongues. The four expansion tongues surround a screw channel into which a screw can be inserted as a spreading element for spreading the expansion anchor. When spreading, the expansion tongues move radially outwardly away from each other, widening the slots between the expansion tongues. If the expansion dowel spread in a wellbore, the expansion tongues are pressed flat against the borehole wall with a large spreading pressure, which in one

CONFIRMATION COPY Solid solid building material such as concrete, a high holding force between the anchoring ground and the expansion anchor can be transferred. However, the expansion anchor is only conditionally suitable for softer, porous building materials such as aerated concrete, as in these materials too large spreading pressure, which is exerted by the expansion tongues on the anchoring ground, leads to the local destruction of the porous structure of the building material.

The object of the invention is to provide an expansion dowel with which a high holding power can be transmitted even in soft, porous building materials. This object is achieved by a Spreizdübel with the features of claim 1. The expansion plug according to the invention made of plastic has a spreading region with at least two primary expansion tongues, which are connected to each other in particular at its front and at its rear end by a sleeve-shaped portion. The primary expansion tongues are mutually movable in the radial direction, for example, separated by a slot or connected by a hinge, a stretchable spray skin or movable via connecting webs. In particular, the primary expansion tongues are connected to each other at their front and rear ends in the insertion direction by sleeves. In this context, the term "insertion direction" refers to the direction in which the expansion dowel according to the invention is introduced into a borehole in the anchoring base as planned.The primary expansion tongues extend in the longitudinal direction of the expansion anchor and at least partially surround a spreading channel Direction meant in which the longitudinal axis of the dowel extends. The longitudinal direction is thus parallel to the insertion direction. The spreading channel serves to receive a spreading element, for example a screw or a nail, with which the spreading region can be spread open. With the spreading element introduced into the expansion channel, the primary expansion tongues are moved from a non-spread state to a spread state essentially exclusively radially outward and away from one another. In this case, "radial" means "orthogonal to the longitudinal axis of the expansion anchor" or "orthogonal to the longitudinal direction." The expansion anchor according to the invention also has at least one secondary expansion tongue which is arranged between the primary expansion tongues is movable substantially exclusively in the radial direction, that in an expanded state, an existing between the primary expansion tongues opening of the lateral surface of the expansion anchor in Essentially completely. By "substantially complete" it is meant that at least a majority of the openings created or existing during the spreading between the primary expansion lices are closed by the secondary expansion lobe or by a plurality of secondary expansion laces.

If the expansion plug according to the invention is spread open, the two primary expansion tongues are moved radially away from each other outwards, whereby the distance between the primary expansion tongues increases and an opening in the lateral surface of the expansion anchor is created or an existing opening is widened. In this opening, the at least one secondary expansion tongue is moved by the expansion element. Are in the spread state between the primary expansion tongues multiple openings of the lateral surface, so several secondary expansion tongues may be provided to close the existing openings. In particular, the number of secondary expansion tongues corresponds to the number of openings present in the expanded state between the primary expansion tongues.

By closing the opening or the plurality of openings is achieved that existing in the expanded state lateral surface of the expansion anchor, which can come into contact with the borehole wall, is increased. In the expansion dowels known from the prior art while spreading the openings between the expansion tongues are widened and the expansion tongues are pressed against the borehole wall, the lateral surface, which can come into contact with the borehole wall, but does not change during spreading. The spreading forces which arise during spreading and which act on the anchoring base are not distributed over a larger lateral surface, as is the case with the expansion anchor according to the invention.

An enlarged in the spread state lateral surface has the advantage that the to be transferred to the anchoring base holding force over a larger area, so that the surface pressure is less than if there are unsealed openings between the expansion tongues. Especially with relatively soft, porous building materials, such as aerated concrete, a high surface pressure of disadvantage, since it can lead locally to a destruction of the anchoring ground, whereby the transferable between expansion dowel and anchoring base holding power is reduced. As a result of the filling in of the existing opening by the secondary expansion tongue or the filling of existing openings by a plurality of secondary expansion tongues, the latter is spread over the borehole wall by the expansion tongues exerted pressure over the lateral surface of the expansion anchor distributed over a large area and avoided destruction of the porous building material, which is achieved with the expansion dowel according to the invention in a porous anchoring a relatively large holding force.

Preferably, the at least one secondary expansion tongue has a cross-section which tapers in the radial direction outwards at least in sections. In particular, the taper extends over at least 30% of the radial extent of the secondary spreader tongue. If the at least two primary expansion tongues are moved radially away from one another during spreading of the expansion anchor, the opening between the two primary expansion tongues increases. At the same time, during spreading, the at least one secondary expansion tongue is moved radially outwards into the widening opening. Due to the taper, the secondary expansion lance may continue to penetrate the expanding opening as the opening widens. The opening is therefore filled regardless of the degree of expansion substantially by the secondary expansion tongue and the power transmission available for effective lateral surface of the expansion anchor is substantially always closed and thus increased. With a continuous widening of the opening during spreading, the lateral surface also increases continuously. If a plurality of secondary expansion tongues are arranged on the expansion dowel according to the invention, several or all of these expansion tongues may have a corresponding cross section.

Preferably, the taper is configured such that the secondary expansion tongue has a wedge-shaped cross-section. It has been found that such a shaped cross-section is advantageous for the penetration and filling of the opening during the bracing.

In particular, the taper is configured such that it substantially completely fills the opening widening during the spreading, even if the expansion dowel is not yet fully expanded. This has the advantage that, regardless of the degree of spreading, so the actual existing outer diameter of the expansion anchor, the largest possible lateral surface for power transmission is available: If the expansion plug according to the invention, for example, used in a borehole in a hard, unyielding anchoring ground as concrete, so the primary expansion tongues are not displaced so far in the radial direction outward when spreading as when using the same expansion element in one softer ground of anchoring such as aerated concrete is the case. The achievable in the borehole diameter of the expansion anchor is smaller in the concrete.

Due to the taper, however, the secondary expansion tongue can also penetrate into the opening between the primary expansion tongues even when not fully widened and fill them, so that the largest possible lateral surface for force transmission is available even if the opening is not completely widened. In the case of a very soft anchoring base, the expansion anchor will initially locally destroy the anchoring ground due to the expansion pressure until the lateral surface enlarged by the bracing is so large or the expansion pressure due to the enlarged lateral surface is so reduced that the anchoring base can absorb the spreading pressure.

Furthermore, it is preferred that the primary expansion tongues and the secondary expansion tongue are beveled in a triangular manner on their sides facing the expansion channel. If there are a plurality of secondary expansion tongues, in particular all secondary expansion tongues are beveled triangularly at their sides facing the expansion channel. By chamfering is achieved that the expansion tongues extend relatively far radially inward and thus can tighten the screw relatively strong. The stronger the tightening channel is narrowed, the greater the maximum achievable radial spread of the expansion tongues. The achievable during spreading of the diameter of the expansion anchor is greater, the smaller the diameter of the screw is in the unexpanded state of the expansion anchor. "Diameter" here is to be understood as meaning the diameter of a circumference circumscribing the cross section of the expansion anchor or the diameter of an inscribed circle describing the expansion channel.

In order to achieve the greatest possible radial spread of the expansion anchor according to the invention, the at least one secondary expansion tongue lies in the unexpanded state on at least one primary expansion tongue, preferably on at least two primary expansion tongues. This ensures that in the unexpanded state, the largest possible proportion of the cross section of the expansion anchor is filled with material from which the expansion dowel consists. Cavities and slots between the expansion tongues that reduce the amount of material that can be moved radially outwardly during spreading are reduced. In order to achieve the largest possible reduction of slots and cavities, it is further preferred that the secondary expansion tongue is essentially enclosed by the primary expansion tongues in the unexpanded state of the expansion anchor.

The expansion anchor according to the invention is in particular made of plastic by injection molding. For example, manufacture is by a two-component injection molding process, preferably with the primary expansion tongues and the secondary expansion tongues made as two separate components of the same material. Alternatively, the expansion tongues can also be made of different materials. In particular, during manufacture, the primary and secondary expansion tongues are sprayed without clearance, so that adjacent primary and secondary expansion tongues abut each other and there are no slots or cavities between them.

The invention will be explained in more detail with reference to two embodiments illustrated in the drawings.

Show it:

Figure 1 shows the cross section of a first expansion dowel according to the invention in an unexpanded state;

Figure 2 shows the cross section of the first expansion dowel according to the invention in a spread state;

Figure 3 shows the cross section of a second expansion dowel according to the invention in an unexpanded state; and

Figure 4 shows the cross section of the second expansion dowel according to the invention in a spread state.

In the figures 1 and 2, the cross section of the expansion region of a first expansion dowel 1 according to the invention is shown. The expansion anchor 1 according to the invention has two primary expansion tongues 2, which are connected at their front and rear ends by sleeve-shaped sections (not shown), as is known from the expansion anchor shown in the European patent application EP 0 834 659 A1. The two primary expansion tongues 2 extend in the longitudinal direction of the expansion anchor 1 along its longitudinal axis L which is orthogonal to the plane of the drawing. The cross sections of the two primary expansion tongues can be simplified by semicircular segments. In the unexpanded state, the circular arcs of the two segment-shaped primary expansion tongues 2 essentially form the lateral surface 3 of the expansion anchor 1. The two primary expansion tongues 2 are separated by a slot 4 in the region of the chords 5 of the segments over a substantial part of the diameter of the expansion anchor 1 and only at one end of the tendons 5 in the region of the lateral surface 3 via a hinge-like connection 6 rotatably connected to each other. The slot 4 intersects on the opposite side of the compound 6, the lateral surface 3 of the expansion anchor 1 and forms an opening 9 in the lateral surface 3. Between the two primary expansion tongues 2, an expansion channel 7 is formed centrally. The spreading channel 7 is triangular in shape and comprises about 5% to 10% of the cross-sectional area. The expansion channel 7 is encompassed by the two primary expansion tongues 2 with the sides 19 and serves to receive a spreading element 8 shown in Figure 2, here in the form of a screw (Figure 3) with thread 17 and screw head 18. The expansion element 8 could also be smaller, but in particular also be significantly larger in diameter. Between the expansion channel 7, the opening 9 and the two primary expansion tongues 2, a secondary expansion tongue 10 is arranged, which has a cross section which consists of a radially outwardly η triangular portion 11 and a screw channel 7 facing the trapezoidal region 12. The triangular-shaped portion 11 is formed as an isosceles triangle whose tip is directed radially, in the radial direction η, outwards. The triangular-shaped portion 11 and the trapezoidal portion 12 are formed symmetrically with respect to the radial direction η. The shorter side 16 of the trapezoidal region 12 faces the expansion channel 7 and rounded concavely for receiving the expansion element 8. The cross section of the secondary expansion tongue 10 tapers in the triangular-shaped region 11 in the radial direction in a wedge-shaped outward direction, while the secondary expansion tongue 10 is bevelled triangularly on its side 16 facing the expansion channel 7. The secondary expansion tongue 10 is in the unexpanded state (Figure 1) substantially over the entire surface and without spacing on the two primary expansion tongues 2, which surround the secondary expansion tongue 10 substantially. In the area in which the secondary expansion tongue 10 rests against the primary expansion tongues 2, the two primary expansion tongues 2 have a cavity that is complementary to the cross section of the primary expansion tongue 2, so that the two primary expansion tongues 2 rest against their ends Spreizkanal 7 facing sides 20 are also tapered triangular. The shape of the primary expansion tongues 2, which was previously described as semicircular segments, is excluded in mirror image form by the cavities on the side of the tendons 5. Figure 2 shows the expansion anchor 1 according to the invention in a spread state after the expansion element 8 has been introduced into the expansion channel 7. By the expansion element 8, the two expansion tongues 2 are pressed apart and pivoted about an axis of rotation, which is formed by the hinge-like compound 6. The primary expansion tongues 2 move away from each other due to the rotational movement in the radial directions r ₂ , r ₃ , whereby the opening 9 is widened. By introducing the expansion element 8 into the expansion channel 7, the secondary expansion tongue 10 is moved in the radial direction n outwardly and moved into the opening 9, so that the outer side 13 of the secondary expansion tongue 10 rests against the primary expansion tongues 2 and between the two primary expansion tongues 2 in the lateral surface 3 existing opening 9 substantially completely fills. Due to the wedge-shaped tapering of the triangular-shaped region 11 of the secondary expansion tongue 10, the secondary expansion tongue 10 can also at least partially penetrate into the opening 9 and fill it substantially completely when the opening 9 has not yet been completely widened. When spreading the expansion anchor 1 thus no cavities or slits in the lateral surface 3 of the expansion anchor 1, but the lateral surface 3 is increased by the lying in the opening part 9 of the outer side 13 of the secondary expansion tongue 10.

FIGS. 3 and 4 show the cross section of a second expansion dowel 101 according to the invention, which differs substantially from the above-described first expansion dowel 1 according to FIGS. 1 and 2 in that it has two secondary expansion tongues 110, each of which has a cross section. which essentially corresponds to the cross section of the secondary expansion tongue 10 of the first expansion anchor 1 according to the invention. In order to avoid repetition, only the differences between the two expansion anchors 1, 101 will be discussed below.

The two primary expansion tongues 102 are separated by a continuous slot 104. A hinge-like connection between the two primary expansion tongues 102 does not exist in this case. The two primary expansion tongues 102 each have an inside on their side 119 facing the expansion channel 107 lying, pointing to the spreading channel 107 triangular web 114 with a u-shaped groove 115 which serves to receive the expansion element 108 (Figure 4). The two U-shaped grooves 115 of the primary expansion tongues 102 surround and, together with the expansion channel 107 facing sides 116 of the secondary expansion tongues 110, the expansion channel 107. In the unexpanded state (Figure 3) are the expansion tongues 102, 110 over the entire surface to each other, so that no slots or cavities in the cross section of the expansion anchor 101 are present except the oval expansion channel 107. If now, as shown in Figure 4, a spreader 108 introduced into the spreader 107, so the two primary expansion tongues move from the unexpanded state in the expanded state radially outward, in the opposite radial directions r ₂ , r ₃ and thus from each other path. This results in two openings 109, in which the two secondary expansion tongues 110 are also moved by the introduction of the expansion element 108 in the expansion channel 107 radially outward, in the opposite radial directions η, r ₄ , that is, away from each other. As with the first inventive expansion dowel 1 described above, the secondary expansion tongues 110 substantially completely fill the two openings 109 of the lateral surface 103, so that the lateral surface 103 is enlarged by the outer side 113 of the secondary expansion tongues 110 when the expansion dowel 110 is spread apart.

The expansion dowels 1, 101 according to the invention shown in Figures 1 to 4 are made of plastic by injection molding. First, the secondary expansion tongues 10, 110 are produced and then overmolded with the primary expansion tongues 2, 102. It can thus be achieved that the expansion tongues 2, 102, 10, 110 in the unexpanded state can be manufactured substantially without any distance from each other, ie substantially without cavities or slots. In the illustrated expansion dowels 1, 101, the proportion of existing in the unexpanded state cavities is less than 10%, so that in the two illustrated expansion dowels according to the invention 1, 101 a relatively large amount of material is available, which can be displaced to the outside during Verspreizen. In particular, in soft anchoring reasons, a relatively high holding force can be transmitted to the anchoring reason, in conjunction with the enlargement of the available in the expanded state lateral surface 3, 103. The primary expansion tongues 2, 102 and the secondary expansion tongues 10, 110 may be made of the same material or of different materials. In which in Figures 1 and 2 shown the first inventive expansion dowel 1, both the primary expansion tongues 2 and the secondary expansion tongue 10 of the same material, namely made of polyamide. In the second inventive expansion dowel 101 shown in Figures 3 and 4, the primary expansion tongues 102 are also made of polyamide, while the secondary expansion tongues 1 10 are made of harder, reinforced with glass fibers polyamide.

List of accessories Expansion dowel

I, 101 expansion dowel

2, 102 primary sprain

3, 103 lateral surface

4, 104 slot

5 tendon

6 hinged connection

7, 107 expansion channel

8, 108 expansion element

9, 109 opening

10, 1 10 secondary spreading tongue

I I, I 11 triangular area of the secondary expansion tongue 10, 110 12, 112 trapezoidal area of the secondary expansion tongue 10, 1 10

13, 113 outside of the secondary expansion tongue 10, 110

1 14 triangular bridge

1 15 groove

16, 116 of the expansion channel 7, 107 facing side of the secondary

Spreader tongue 10, 110

17, 117 thread

18, 118 screw head

19, 119 of the expansion channel 7, 107 facing side of the primary

Spreader tongue 2, 102

L longitudinal axis

Π, r ₂ , r ₃ , r ₄ radial direction

Claims

claims

Expansion anchors (1, 101) made of plastic,

with at least two primary spreader tongues (2, 102),

extending in the longitudinal direction of the expansion anchor (1, 101), which at least partially surround an expansion channel (7, 107), and by means of a in the expansion channel (7, 107) insertable expansion element (8, 108) of an unexpanded state in one substantially only radially outwardly and away from one another, and with at least one secondary expansion tongue (10, 110),

which is arranged between the primary expansion tongues (2, 102), characterized in that

the secondary expansion tongue (10, 110) is movable essentially exclusively in the radial direction in this way,

that in an expanded state, it substantially completely fills an opening (9, 109) of the circumferential surface (3, 103) of the expansion anchor (1, 101) between the primary expansion tongues (2, 102).

Expansion dowel according to claim 1, characterized

the secondary expansion tongue (10, 110) has a cross-section which tapers in the radial direction outwards at least in sections.

Expansion dowel according to claim 2, characterized

the secondary expansion tongue (10, 110) has a wedge-shaped cross-section.

Expansion dowel according to one of claims 1 to 3, characterized

in that the primary expansion tongues (2, 102) and the secondary expansion tongues (10, 110) are bevelled triangularly at their sides (16, 116) facing the expansion channel (7, 107).

Expansion dowel according to one of claims 1 to 4, characterized in that the secondary expansion tongue (10, 110) rests in the unexpanded state on at least one primary expansion tongue (2, 102).

Expansion dowel according to one of claims 1 to 5, characterized

in that the primary expansion tongues (2, 102) essentially surround the secondary expansion tongue (10, 110) in the unexpanded state.

Expansion dowel according to one of claims 1 to 6, characterized

the primary expansion tongues (2) and the secondary expansion tongue (10) are made of the same material.

Expansion dowel according to one of claims 1 to 6, characterized

that the primary expansion tongues (102) and the secondary expansion tongue (110) are made of different materials.

Expansion dowel according to one of claims 1 to 8, characterized

that in the expanded state between the primary expansion tongues (102) a plurality of openings (109) of the lateral surface (103) of the expansion anchor (101) are present and that for filling the openings (109) a plurality of secondary expansion tongues (110) are present.

Expansion dowel according to claim 9, characterized

the number of secondary expansion tongues (110) corresponds to the number of openings (109).