EP3918153B1 - Transport anchor having a pressure element and method of producing a transport anchor - Google Patents

Description

• einen bügelförmigen Grundkörper mit
  • einem bogenförmigen Zentralabschnitt zum Einhängen von Anschlagmitteln,
  • zwei vom Zentralabschnitt ausgehenden, sich im Wesentlichen parallel zueinander erstreckenden Ankerschenkeln,
• ein zwischen den Ankerschenkeln angeordnetes Druckelement.

The present invention relates to a lifting anchor for double and sandwich walls, comprising

• a bow-shaped body with
  • an arcuate central section for hanging slings,
  • two anchor legs extending essentially parallel to one another, starting from the central section,
• a pressure element arranged between the armature legs.

Furthermore, the invention relates to a method for producing such a transport anchor.

Such transport and laying anchors are used for the transport of so-called double and sandwich walls. They are usually cast into concrete walls in the precast concrete industry and are used on the one hand as a transport device to which lifting gear can be hung, but on the other hand as spacers during the concreting process. Sandwich or sandwich concrete walls have insulation between the concrete walls. In the following, for the sake of simplicity, the terms double wall are used as synonyms for double walls and sandwich walls.

During the transport process, large forces act on the transport anchor. In order to prevent the armature legs from moving towards one another and, in the worst case, from being detached from the walls, the pressure element for absorbing forces is arranged between them.

For example, from the reference DE 100 38 249 B4 a transport anchor is known in which the pressure element is made of steel and welded onto the anchor legs. The large forces mentioned act on this weakened area when the double walls are being transported, as a result of which there is a very high risk of the weld seams tearing and the subsequent excessive deformation of the transport anchor. A similar pressure element made of steel is known from the publication EP 3 029 220 A1 out. In this case, the pressure element is preferred used by spot welding. The welding process also changes and weakens the surrounding material locally, which also reduces stability. In both cases, the welded joints can cause the transport anchor to break out of the concrete, which in turn can cause the precast concrete element to fall.

The DE 20 2014 103 774 U1 describes a transport anchor in which the pressure element made of steel is slidably held on the base body. In principle, the pressure element should remain in its position due to the diameter of through-openings unless larger forces are acting from the outside: However, this certainly cannot be guaranteed. In this respect, the pressure element can also move during installation, which leads to corresponding disadvantages. For this reason, lifting anchors are known that use a flexible material, such as wood, instead of a pressure element made of steel. Wood is able to absorb the forces that occur, but the disadvantage is that wood can absorb liquid, which on the one hand causes the pressure element to rot, but on the other hand can also freeze and expand. Both are disadvantageous, since damage to the double wall or the precast concrete part can also occur afterwards.

The DE 10 2005 009708 A1 describes, for example, a variant in which the pressure element can be made of textile-reinforced concrete. However, it is also essential in this variant that the pressure element should be flexible in response to transverse pressure. In this respect, detachment from the double wall is also possible with this variant.

The FR2948139 discloses a transport anchor according to the preamble of claims 1 or 2.

The production of all lifting anchors described in the prior art is relatively complex and cost-intensive. Cold bridges, weathering or rusting and the relatively high dead weight are also problematic.

The object of the invention is to create a transport anchor that does not have the disadvantages mentioned above. The lifting anchor should nevertheless be able to be produced inexpensively and enable safe use. Furthermore, the transport anchor should not lead to damage or disadvantages even if it remains in the double wall later. The task remains is to propose a method for the production of such a transport anchor.

The object of the invention is achieved by a transport anchor according to claim 1, wherein, among other things, the pressure element is formed from a fiber-reinforced plastics material and has end caps at its two ends, which are each placed with an open side on a free end of the cylindrical pressure element and each have openings, through each of which an anchor leg extends.

The use of a fiber plastic composite material is not known from the prior art. The use of such a material for lifting anchors is considered to be disadvantageous, particularly with regard to the forces to be absorbed. Tests have shown, however, that the disadvantages to be expected in connection with concrete walls, in particular with sandwich concrete walls, are obviously eliminated. The transport anchors according to the invention are perfectly capable of safely absorbing all the necessary forces.

The pressure element made of fiber-reinforced plastic composite material according to the invention is also advantageously watertight, thus preventing the transfer of moisture via the pressure element from one double wall to the other. This is not the case, in particular, with pressure elements made of wood and with tubular, internally hollow pressure elements made of steel.

According to a further, independent aspect of the teaching, the object is also achieved by a lifting anchor according to claim 2, with the pressure element being made of steel and having end caps at both of its ends, each with an open side on a free end of the cylindrical pressure element are placed and each have openings through which an anchor leg extends. The pressure element formed according to this aspect of the teaching from steel instead of fiber-reinforced plastic material has the same advantages with regard to the entire lifting anchor with regard to the connection of the pressure element to the anchor legs, since the connection of the pressure element formed in this embodiment from steel instead of fiber-reinforced plastic material to the anchor legs with the previously described embodiment can be done identically designed end caps. Accordingly, the following advantages of a transport anchor with a pressure element made of fiber-reinforced plastic are also due to this Embodiment of a lifting anchor with a pressure element made of steel transferrable, insofar as the advantages are not explicitly due to the material fiber-reinforced plastic.

In principle, the pressure element can have any desired cross section; round, oval, rectangular or triangular cross sections are particularly suitable. The pressure element can have a groove on its free end faces for each anchor leg, in which the axle leg held by the end caps rests. This further increases the stability.

A major advantage of fiber-reinforced plastic is that no thermal bridges can form. It has a relatively low mass, does not rust and, in contrast to concrete, is very robust. The mechanical and thermal properties of fiber-reinforced plastics can be adjusted using a large number of parameters. In addition to the fiber-matrix combination, the fiber angle, the fiber volume fraction, the layer sequence and much more can be varied. For example, organic, inorganic or also natural fibers can be used. The length of the fibers used can also be varied.

The production of the transport anchor according to the invention can be carried out particularly easily and quickly, in particular by using the advantageous end caps. According to the invention, the end caps are designed as pipe sections which have two opposite openings. Alternatively, the end caps can also be cup-shaped, in which case they have a bottom surface and an adjoining peripheral surface. The cup opening is arranged opposite the bottom surface. Two opposing openings are provided in the end caps or in the peripheral surface of the end caps, through which an anchor leg extends in the assembled final state. The end caps are preferably made of a durable plastic.

When assembling the transport anchor, the end caps are placed on the end of the pressure element made of fiber-reinforced plastic via one of their openings. The anchor legs are each through the openings of End caps are fed through and the pressure element is pushed to the desired position. The inside diameters of the end caps are designed to be somewhat smaller than the outside diameters of the pressure element at the ends. If the elements to be assembled are in the correct position, they are mechanically pressed together, so the end caps are pushed onto the free ends of the pressure element. The elasticity of the end caps is sufficient for them to expand sufficiently. The anchor legs are thus also held firmly in the end caps. The local changes in the welding area usually caused by welding pressure elements to the anchor legs and the breaking of weld seams are excluded.

Alternatively, it is possible to press the end caps first and only then insert the anchor legs through the openings. This assumes that the openings remain free during the pressing process.

The pressure element can be arranged in the area of the transport anchor in which the anchor legs run essentially parallel to one another. However, the pressure element can preferably also be arranged in a transition area between the arcuate central section and the anchor legs extending parallel to one another. Finally, an arrangement within the arcuate central section is also conceivable.

The central section can be formed by two straight leg sections running towards one another, which are connected to one another via a relatively short arc. Thus, the central portion has an approximately triangular shape overall. Alternatively, the arched base body can also run curved over its entire length, starting from the transition area.

The anchor legs can be straight over their entire length, but alternatively they can also have free end regions which are formed out of the otherwise straight extension of the anchor legs. The reshaping can take place in all directions, for example towards one another, away from one another, or parallel to one another, or in different directions.

The base body is usually formed from solid steel or a single strand of steel. In a particularly advantageous embodiment variant, however, this can also consist of a wire or wire cable. A stainless steel rope or cable is preferable, for example a galvanized steel cable, but it is also conceivable to use a rope with sufficient tensile strength, for example made of Kevlar or carbon. Using a cable or rope makes manufacturing easier and faster due to the flexibility. Since a wire or steel cable consists of a large number of strands or wires, the use of the transport anchor according to the invention is safer. Usually not all the strands tear at the same time, but rather individually, so that there is often still time to detach the double walls before the rope tears completely.

Furthermore, it has been shown that when wire ropes are used as the base body, this can be delivered in the coiled state. The approximately parallel free sections of the axle stubs of the manufactured transport anchors can be rolled up and fixed in the rolled up position with the aid of fastening means. This reduces the overall length of the transport anchor, which means that smaller pack sizes can be achieved. As a result, the transport costs and the transport effort are significantly reduced. The use of plastic retaining clips to fix the rolled-up steering knuckles has proven to be particularly suitable. Alternatively, the retaining clips can also be made from a different material, for example from wire or steel. Ultimately, they must be able to secure the rolled up knuckles against unwinding.

The openings for inserting the base body or the armature legs can preferably run obliquely or be offset from one another, so that the armature legs are passed through the pressure element at an angle and do not run parallel to one another. In the direction of their free ends, the distance between the two anchor legs increases. This is particularly advantageous when the base body is formed by a flexible steel cable. In this case, the arched central section deforms above the pressure element when the component to be transported is lifted. The arcuate central portion is stretched. Under load, the armature legs thus run straight through the pressure element due to the oblique openings.

Furthermore, it can be provided according to the invention that the pressure element is either stationary, ie immovably connected to the base body, but it can also be provided that this is displaceable along the anchor legs. The different connection can be determined by the production method according to the invention by selecting the pressure via which the end caps are pressed onto the pressure element in the axial direction, with which they therefore clamp the steering knuckle.

The base body of a transport anchor according to the invention can preferably be shortened in that the free ends have cross-sectional reinforcements, for example in the form of tube sections or cylindrical bodies. This improves the connection of the base body or the anchor legs with the respective double wall. The cross-sectional reinforcements can also be made of a different material.

In order to prevent the anchor legs from floating during installation in the double wall, a fixed or detachable fixing element can advantageously also be provided, which runs approximately parallel to the pressure element between the axle legs. This can also be made of steel, but also made of plastic or another suitable material.

Alternatively, however, it can also be advantageous if the free ends of the anchor legs are tapered. This makes it easier to insert the anchors into the double walls, especially if they have steel reinforcement.

Fig. 1:

eine erste Ausführungsvariante eines erfindungsgemäßen Transportankers mit einem Grundkörper aus Stahl, in perspektivischer Darstellung,

Fig. 2:

eine zweite Ausführungsvariante eines erfindungsgemäßen Transportankers mit einem Grundkörper aus einem Stahlseil, in zwei perspektivischen Darstellungen,

Fig. 3:

eine vergrößerte Ansicht einer Endkappe mit eingeführtem Stahlseil,

Fig. 4:

den Transportanker aus Figur 2 in Transportzustand. 3 in Draufsicht,

Fig. 5

einen erfindungsgemäßen Transportanker mit Querschnittsverstärkungen,

Fig. 6:

einen erfindungsgemäßen Transportanker mit Fixierungselement in perspektivischer Darstellung,

The invention is explained in more detail with reference to the following figures. These show various embodiments of a transport anchor according to the invention, with other shapes being conceivable. Show it:

Figure 1:

a first embodiment of a transport anchor according to the invention with a base body made of steel, in a perspective view,

Figure 2:

a second embodiment of a transport anchor according to the invention with a base body made of a steel cable, in two perspective views,

Figure 3:

an enlarged view of an end cap with inserted steel cable,

Figure 4:

the transport anchor figure 2 in transport condition. 3 in top view,

figure 5

a transport anchor according to the invention with cross-sectional reinforcements,

Figure 6:

a transport anchor according to the invention with a fixing element in a perspective view,

The Figures 1 to 6 show different variants of a transport anchor 20. The figures and embodiments shown serve for explanation, individual features of the individual embodiments can be combined with features of other embodiments.

The transport anchor 20 has a base body 22 with an arcuate central section 24 and adjoining anchor legs 26 running parallel to one another. Furthermore, a pressure element 28 arranged between the armature legs 26 is shown.

According to the invention, the base body is preferably made of steel, a steel cable or a cable made of another resistant, suitable material. The pressure element 28 is formed from a fiber plastic composite material.

According to the invention, the pressure element 28 can be arranged at various points along the course of the base body. The figures 1 and 2 show an example of a possible positioning, namely adjacent to a transition area between the armature legs 26 and the arched central section 24. Alternatively, the pressure element 28 can be arranged in the transition area, at a greater distance from the transition area 30 or also within the arched central section 24.

The arcuate central portion 24 may have a generally triangular shape formed by two straight leg portions 32 merging into a relatively narrow arc 34 . This is the case, for example, with a base body 22 made of steel or steel wire ( figure 1 ). As an alternative to this, the arched central section 24 can also be designed arched overall, in particular when using a steel cable ( figure 2 ).

At the free ends of the pressure element 28, the end caps 62 close with openings 52 for inserting the armature leg 26 ends. In the exemplary embodiment shown, the end caps 62 are essentially tubular and are pushed onto the ends of the pressure element 28 with one of their open sides. Due to the fact that the inner diameter of the end caps 62 is smaller than the outer diameter of the pressure element 28, the end caps 62 must be pressed or pressed onto the pressure element 28. They widen as a result and are held firmly and immovably on the pressure element 28 after assembly due to their elasticity.

The openings 52 through which the armature legs 26 extend are arranged exactly opposite one another in the exemplary embodiment shown, so that the armature legs 26 run parallel to one another and essentially at right angles to the main extension of the pressure element 28 . Alternatively, the openings 52 can also be arranged at an angle or offset from one another, so that the armature legs 26 are guided through the end caps 62 at an angle and do not run parallel to one another in the further course.

3 12 is an enlarged view of end cap 62 with steel cable inserted through openings 52. FIG. The design of the end caps 62 as a tubular section has the advantage that when the transport anchor 20 is poured into the component to be transported, liquid concrete can penetrate from the outside through the open free end of the end cap 62, which improves the subsequent stability and tensile strength of the overall construction. The pressure element 28 can have a groove on each of its two free end faces, in which the armature legs come to rest.

figure 4 shows the transport anchor figure 2 in transport condition. It can be seen that the use of a steel cable advantageously offers the possibility consists of rolling it up and provisionally fixing it with the aid of fasteners 60 for transport or for packaging. Shown are retaining clips that can be pressed onto the steel cable. Alternatively, fastening means 60 can also be made from a different material, for example from wire or steel.

The armature limbs 26 can, on the one hand, be conical or tapered at their free ends, but cross-sectional reinforcements 36 can also be provided at the free ends (see FIG figure 5 ). The cross-sectional reinforcements 36 can be made of the same material as the base body 22, but they can also be made of other materials. Shown is the use of a base body 22 made of a steel cable; of course, the cross-sectional reinforcements 36 can also be combined with a base body made of steel or steel wire.

figure 6 shows a fixing element 48, which runs essentially parallel to the pressure element 28 and holds the two anchor legs 26 in their position or towards one another under pretension. Fixing elements 48 are particularly useful when using a base body 22 made of steel or steel wire. By connecting, preferably welding, the fixing element 48 to the two anchor legs 26, the overall length of the anchor legs 16 can be additionally reduced.

The in the Figures 1 to 6 Illustrated variants with the pressure element 28 made of a fiber plastic composite material can alternatively also be modified in such a way that the pressure element 28 is made of steel. The advantages shown can also be transferred to such an embodiment variant.

The end caps 62 are particularly advantageously formed from a plastic.

As a result, the elements of pressure element 28, armature leg 26 and end caps 62 can be pressed together in a particularly simple manner.

Claims (15)

1. A transportation anchor (20) for double and sandwich walls, comprising

   - a bow-shaped base body (22), with

   - an arch-shaped central section (24) for hooking-in lifting means,

   - two anchor legs (26) projecting from the central section (24), extending essentially parallel to one another,

   - a pressure element (28) arranged between the anchor legs (26),

   wherein

   - the pressure element (28) is made from a fibre plastic composite material,

   - the pressure element (28) comprises at its two ends cup-shaped or tubular section-shaped end caps (62), which are each placed with an open side on a free end of the cylindrical pressure element (28),

   characterised in that two openings (52) lying opposite one another are provided in the peripheral surface of the cup-shaped or tubular section-shaped end caps (62), through each of which openings an anchor leg (26) extends in the final assembled state.
2. The transportation anchor (20) for double and sandwich walls, comprising

   - a bow-shaped base body (22), with

   - an arch-shaped central section (24) for hooking-in lifting means,

   - two anchor legs (26) projecting from the central section (24), extending essentially parallel to one another,

   - a pressure element (28) arranged between the anchor legs (26),

   wherein

   - the pressure element (28) comprises at its two ends cup-shaped or tubular section-shaped end caps (62), which are each placed with an open side on a free end of the cylindrical pressure element (28),

   characterised in that the pressure element (28) is made of steel, and that two openings (52) lying opposite one another are provided in the peripheral surface of the cup-shaped or tubular section-shaped end caps (62), through each of which openings an anchor leg (26) extends in the final assembled state.
3. The transportation anchor (20) according to claim 1 or 2, characterised in that a maximum inner diameter (D2) of the end caps (62) is smaller than a maximum outer diameter (D1) of the free ends of the pressure element (28), as a result of which the end caps (62) are held on the pressure element (28) by friction.
4. The transportation anchor (20) according to any one of claims 1 to 3, characterised in that the openings (52) are arranged diametrically opposite one another, so that the anchor legs (26) are passed through at right angles to the extension of the pressure element (28).
5. The transportation anchor (20) according to any one of claims 1 to 3, characterised in that the openings (52) run obliquely to the straight extension of the pressure element (28), so that the anchor legs (26) pass through the pressure element (28) at an angle.
6. The transportation anchor (20) according to any one of claims 1 to 5, characterised in that the bow-shaped base body (22) is made of steel rope.
7. The transportation anchor (20) according to any one of claims 1 to 5, characterised in that the bow-shaped base body (22) is made of steel.
8. The transportation anchor (20) according to any one of claims 1 to 7, characterised in that the pressure element (28) and the end caps (62) have a corresponding cross-sectional shape from the group round, oval, rectangular or triangular.
9. The transportation anchor (20) according to any one of claims 1 to 8, characterised in that the pressure element (28) is arranged in the course of the anchor legs (26) extending parallel to one another.
10. The transportation anchor (20) according to any one of claims 1 to 9, characterised in that the pressure element (28) at each of its free ends has a slot on the end side, in each of which an anchor leg (26) extends.
11. The transportation anchor (20) according to any one of claims 1 to 10, characterised in that a thermally insulating separating body (38) is provided in the course of the pressure element (28), which divides the pressure element (28) into a first pressure element section (40) and a second pressure element section (42).
12. The transportation anchor (20) according to any one of claims 1 to 11, characterised in that a fixing element (48) is provided, which runs essentially parallel to the pressure element (28) and fixes the anchor legs (26) in their position.
13. The transportation anchor (20) according to any one of claims 1 to 12, characterised in that the anchor legs (26) comprise cross-sectional reinforcements (36) at their free ends.
14. The transportation anchor (20) according to any one of claims 1 to 13, characterised in that the anchor legs (26) comprise an end section (50) at each of their free ends, which projects at an angle to the essentially straight extension of the anchor legs (26).
15. A method for the production of a transportation anchor (20) with the features of claims 1 to 14, characterised by the process steps

    - production of a bow-shaped base body with an arch-shaped central section (24) and two anchor legs (26) projecting from the central section (24), extending essentially parallel to one another,

    - production of a longitudinal pressure element (28) made from a fibre plastic composite material or steel,

    - production of ends caps (62) with a corresponding cross section at the free ends of the pressure element (28), wherein the maximum inner diameter of the end caps is smaller than a maximum outer diameter of the free ends of the pressure element (28) and each of the end caps further comprises openings (52) for passing-through anchor legs (26),

    - arrangement of the end caps (62) on the pressure element (28),

    - passing the anchor legs (26) through the openings (52) and positioning of the pressure element (28) at the final position,

    - pressing of the elements pressure element (28), anchor legs (26) and end caps (62) with one another.

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