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Title:
TENSION LOCK WITH AN ADAPTER FOR JOINING PREFABRICATED CONCRETE ELEMENTS
Document Type and Number:
WIPO Patent Application WO/2017/093471
Kind Code:
A1
Abstract:
The present invention relates to a tension lock with an adapter for joining prefabricated concrete elements, which is substantially formed to be shell-shaped, with at least two side walls which are substantially planar and disposed parallel opposite to each other, and at least two side walls which in a cross-sectional view at least in sections converge conically, and with a receiving space accessible at least from the outside via an access opening, and additional passage sections preferably disposed opposite to each other which open into the receiving space and which are provided as passage openings for the insertion of fastening devices, where the passage sections are formed in the planar side walls and have at least one insertion opening which is arranged in the base of the tension lock facing the access opening, where the adapter is arranged in the receiving space of the tension lock and is at its side facing the base of the tension lock at least in sections formed to be curved, preferably barrel-shaped, so that a positive fit between the tension lock and the adapter arises at least in sections and the adapter has a planar bearing surface at least in sections at its side facing the access opening, and the adapter has an opening disposed opposite to the insertion opening of the tension lock for the insertion of fastening devices. The present invention additionally relates to a construction kit for joining prefabricated concrete elements with at least one tension lock according to the invention, at least one anchor, preferably a pigtail anchor, and at least three fastening devices, where the longitudinal axes of the fastening devices in the passage sections in the planar side walls extend substantially parallel to one another, and the longitudinal axis of the fastening device in the opening of the adapter extends substantially perpendicular thereto.

Inventors:
JAESCHKE KLAUS (DE)
DITTMAR JAN (DE)
Application Number:
PCT/EP2016/079563
Publication Date:
June 08, 2017
Filing Date:
December 02, 2016
Export Citation:
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Assignee:
BT INNOVATION GMBH (DE)
International Classes:
E04B1/04; E04B1/41; E04B5/02
Domestic Patent References:
WO2013131530A12013-09-12
Foreign References:
NL6408402A1966-01-24
Attorney, Agent or Firm:
GRÜNECKER PATENT UND RECHTSANWÄLTE PARTG MBB (DE)
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Claims:
CLAIMS

1 . Tension lock (1 ) with an adapter (23) for joining prefabricated concrete elements (10) which is substantially formed to be shell-shaped, with at least two side walls (7, 8) which are substantially planar and disposed parallel opposite to each other, and at least two side walls (5, 6) which in a cross-sectional view at least in sections converge conically, and with a receiving space (2) accessible at least from the outside via an access opening (9), and additional passage sections (3, 4) preferably disposed opposite to each other which open into said receiving space (2) and which are provided as passage openings (3, 4) for the insertion of fastening devices (13), where said passage sections (3, 4) are formed in said planar side walls (7, 8), and with at least one insertion opening (20) which is arranged formed in the base (21 ) of said tension lock (1 ) disposed opposite to said access opening (9), where said adapter (23) is arranged in said receiving space (2) of said tension lock (1) and is at its side facing said base (21 ) of said tension lock (1 ) at least in sections formed to be curved, preferably barrel-shape, so that a positive fit between said tension lock (1 ) and said adapter (23) arises at least in sections and said adapter (23) has a planar bearing surface (24) at least in sections at its side facing said access opening (9), and said adapter (23) has an opening (25) disposed opposite to said insertion opening (20) of said tension lock (1 ) for the insertion of fastening devices (13).

2. Tension lock (1 ) with said adaptor (23) according to claim 1 , characterized in that said tension lock (1) preferably has a tensile strength of 400 N/mm2 to 800 N/mm2, preferably 450 N/mm2 to 780 N/mm2, particularly preferably 500 N/mm2 to 750 N/mm2.

3. Tension lock (1 ) with said adaptor (23) according to claim 1 or 2, characterized in that said adapter (23) preferably has a tensile strength of 400 N/mm2 to 800 N/mm2, preferably 450 N/mm2 to 780 N/mm2, particularly preferably 500 N/mm2 to 750 N/mm2.

4. Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that said conically tapering side walls (5, 6) are joined to each other such that the cross-section is V-shaped or U-shaped.

5. Tension lock (1 ) with said adaptor (23) according to at least one of the preceding claims, characterized in that said passage sections (3, 4) are preferably offset by 90° and are designed as a slot (3) and/or elongated hole (4), and one of said passage sections is preferably designed as a slot (3) and another one of said passage sections as an elongated hole (4) and/or said slot (3) is open at least on one side and preferably opens to said access opening (9).

6. Tension lock (1 ) with said adaptor (23) according to at least one of the preceding claims, characterized in that said tension lock (1 ) and/or said adapter (23) is at least in sections made of annealed cast iron or spherulitic graphite cast iron.

7. Tension lock (1 ) with said adaptor (23) according to at least one of the preceding claims, characterized in that said tension lock (1 ) and said adapter (23) exhibit the same tensile strength and/or are made of the same material.

8. Tension lock (1 ) with said adaptor (23) according to at least one of the preceding claims, characterized in that said opening (25) in said adaptor (23) is an elongated hole (25) or a slot.

9 Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that the opening area of said opening (25) in said adapter (23) is smaller than the opening area of said insertion opening (20) in said base (21 ) of said tension lock (1 ).

10. Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that the longitudinal axis of said opening (25) in said adapter (23) extends parallel to the longitudinal axis of the curvature (26) of said adapter (23).

1 1. Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that said adapter (23) comprise at least one holding device (27) on the side facing said access opening (9).

12. Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that the width (B) and the height (A) of said tension lock (1 ) have the same length, or that the width (B) is preferably at least 15 percent smaller than the height (A).

13 Tension lock (1 ) with said adapter (23) according to at least one of the preceding claims, characterized in that the height (H) of said adapter (23) is at least one third of a dimension (C) of said tension lock (1 ) from a curved region (28) joining said conically converging sides walls (5, 6) to said access opening (9).

14. Construction kit for joining prefabricated concrete elements (10) comprising at least one tension lock (1 ) with an adapter (23), according to claims 1 to 12, and at least three fastening devices (13) in sections being elongated, each of which is associated with said passage section and said passage opening, where the longitudinal axes of said fastening devices (13) in said passage sections (3, 4) in said planar side walls (7, 8) extend substantially parallel to each other, and the longitudinal axis of said fastening device (13) in said insertion opening (25) of said adapter (23) extends substantially perpendicular thereto.

Description:
Tension lock with an adapter for joining prefabricated concrete elements

The present invention relates to a tension lock with an adapter for joining prefabricated concrete elements as well as a construction kit for joining prefabricated concrete elements comprising at least one tension lock according to the invention with an adapter.

The use of prefabricated concrete elements, which are joined to each other at the construction site, has proven to be advantageous in the construction of new buildings. The buildings can with this technology be constructed quickly and at a low price. High demands are placed on the connection of the concrete elements. The connection is, firstly, to be produced quickly and inexpensively; secondly, the connection must also be able to withstand high long-term loads. Joining the concrete elements is done, for example, with a tension lock as described in WO 2013/131530 A1. With such a tension lock, the concrete elements can be quickly and reliably joined at the construction site.

Although the tension lock can be used in many ways, there are nevertheless installation situations in which the tension lock can not be used.

It is therefore the object of the present invention to provide a tension lock which can be used more universally so that buildings can be constructed in a shorter time and even more cost- effectively. A further object of the invention is to provide a construction kit with such a tension lock.

The object is according to the invention satisfied by a tension lock with an adapter for joining prefabricated concrete elements, which is substantially formed to be shell-shaped, with at least two side walls which are substantially planar and disposed parallel opposite to each other, and at least two side walls which in a cross-sectional view at least in sections converge conically, and with a receiving space accessible at least from the outside via an access opening, and additional passage sections preferably disposed opposite to each other which open into the receiving space and which are provided as passage openings for the insertion of fastening devices, where the passage sections are formed in the planar side walls and have at least one insertion opening which is formed arranged in the base of the tension lock opposite to the access opening, where the adapter is arranged in the receiving space of the tension lock and is at its side facing the base of the tension lock is at least in sections formed to be convex, preferably barrel-shaped, so that a positive fit between the tension lock and the adapter arises at least in sections and the adapter has a planar bearing surface at least in sections at its side facing the access opening, and the adapter has an opening disposed opposite to the insertion opening of the tension lock for the insertion of fastening devices. The tension lock shown in WO 2013/131530 A1 has two passage sections which are formed in the planar side walls and into which fastening device can be inserted. The insertion opening in the base of tension lock 1 is there not used for the insertion of a further fastening device. This insertion opening is used to facilitate access to the receiving space 2, whereby installation of the tension lock is facilitated. In addition, the weight of the tension lock can be reduced by way of this insertion opening. With the adapter of the present invention, also the insertion opening in the base of the tension lock can also be used for inserting a fastening device. This fastening device then extends substantially perpendicular to the fastening devices which are inserted through the passage sections into the planar side walls. In this manner, a truss connection is created and the tension lock can be used even more universally. For example, it is also possible to join prefabricated concrete elements quickly and reliably which are arranged at a right angle to one another. Complex structures which have hitherto been used for such a connection are therefore no longer necessary, whereby savings in time and costs are made possible.

Due to the fact that the tension lock preferably has a tensile strength of 400 N/mm 2 to 800 N/mm 2 , preferably 450 N/mm 2 to 780 N/mm 2 , particularly preferably 500 N/mm 2 to 750 N/mm 2 , the connection can absorb and transfer very high forces. This is advantageous, for example, for the use in structures in earthquake regions and the oscillation demands associated therewith.

If the adapter preferably has a tensile strength of 400 N/mm 2 to 800 N/mm 2 , preferably 450 N/mm 2 to 780 N/mm 2 , particularly preferably 500 N/mm 2 to 750 N/mm 2 , the connection can absorb and transfer even higher forces. In this way, the safety of the structure can be ensured. High demands are placed on the stability of the building particularly in earthquake regions. By using material which has a high strength and toughness, the connection can absorb and transfer high forces.

In a preferred embodiment, the conically converging side walls can be joined to each other such that the cross-section is V-shaped or U-shaped. The passage sections can preferably be offset by 90° and be designed as a slot and/or elongated hole, and one of the passage sections can preferably be designed as a slot and another one of the passage sections can be designed as an elongated hole and/or the slot can be open at least on one side and preferably open to the access opening. The assembly of the prefabricated concrete elements can still further be simplified by the particular shaping of the tension lock according to the invention as well as the arrangement of the passage sections. In particular, various conditions can due to the design and arrangement of the passage sections be taken into account during the assembly of the prefabricated concrete elements, so that the tension lock according to the invention with the adaptor can be used in various situations. The tension lock according to the invention can in this manner be used even more universally, which allows for further savings in costs and time.

It can be advantageous to have the tension lock and/or the adapter at least in sections be made of annealed cast iron or spherulitic graphite cast iron. When embodied as annealed cast iron, the strength and the hardness of the tension lock can be optimally adapted to the installation situation. Annealed cast iron allows for a good adjustability of the toughness and the hardness, especially with thin-walled elements. When embodied as spherulitic graphite cast iron, high strength of the tension lock can be obtained without using any additional annealing process. Furthermore, a low-cost implementation is possible by the use of spherulitic graphite cast iron.

It can be advantageous to have the tension lock and the adapter exhibit the same tensile strength and/or be made of the same material. By using materials with high tensile strengths, high stability of the connection can be enabled.

In another preferred embodiment, the opening in the adapter can be an elongated hole or a slot. The fastening device can therefore be attached even more easily in the tension lock.

Furthermore, it can be advantageous to have the opening area of the opening in the adapter be smaller than the opening area of the insertion opening in the base of the tension lock. Due to the larger opening area of the opening in the base of the tension lock, the fastening device can be passed more easily through the opening. The fastening device can in particular be inserted at different angles. Due to the convex, preferably barrel-shaped configuration of the side of the adapter facing the base of the tension lock, the adapter can be moved in the tension lock and compensate for tolerances such that the fastening device can be inserted more easily into the opening of the adapter. Due to the fact that the opening area of the opening in the adapter is smaller than the opening area of the access opening in the base of the tension lock, the fastening device can be inserted more easily into the tension lock and reliably fastening of the fastening device in the tension lock is obtained at the same time.

Furthermore, it has proven to be advantageous to have the longitudinal axis of the opening in the adapter extend parallel to the longitudinal axis of the curvature of the adapter. Movability of the adapter in the tension lock can in this way be further increased. When the fastening device has been inserted into the tension lock at a certain angle, the opening of the adapter can be adjusted to this angle due to the particular shape of the adapter so that the fastening device is easier insertable into the opening of the adapter. Furthermore, the adapter centers itself automatically during attachment. It can be advantageous to have the adapter comprise at least one holding device on the side facing the access opening. The adapter can with this holding device more easily be inserted into and removed from the tension lock.

In a further advantageous embodiment, the width and the height of the tension lock can have the same length, or the width can preferably be at least 15% less than the height. In this manner, the tension lock has a compact shape and can be more easily mounted in a recess of the prefabricated concrete element.

It can in addition be advantageous to have the height of the adapter be at least one third of a dimension of the tension lock from a curved region joining the conically converging sides walls to the access opening. In this way, an even better foothold of the adapter in the tension lock is ensured.

The above object is also satisfied by a construction kit for joining prefabricated concrete elements comprising at least one tension lock according to the invention with an adapter, and at least three fastening devices in sections being elongated, each of which is associated with the passage section and the insertion opening, where the longitudinal axes of the fastening devices in the passage sections in the planar side walls extend substantially parallel to each other, and the longitudinal axis of the fastening device in the insertion opening of the adapter extends substantially perpendicular thereto.

This solution has the advantage that a truss connection is possible. For example, two prefabricated concrete elements being arranged next to one another can be joined by the tension lock. At the same time, a prefabricated concrete element being arranged at a right angle thereto can be joined by the same tension lock. Tolerances can be compensated for due to the special design of the adapter. This is necessary, for example, when the fastening device is not inserted into the tension lock exactly perpendicular to the opening, but at a certain angle. In this way, the tension lock according to the invention with an adapter can be used more universally in comparison to a conventional tension lock, whereby savings in time and costs are made possible.

The invention shall below be explained in more detail with reference to an embodiment and associated drawings,

where:

Fig. 1 shows a schematic representation of the tension lock according to the invention with insertion openings without the adapter,

Fig. 2 shows a top view of the tension lock according to the invention without the adapter.

Fig. 3 shows a sectional view of Fig. 2 along the line E-E, Fig. 4 shows a sectional view of Fig. 2 along the line D-D,

Fig. 5 shows a sectional view of Fig. 2 along the line C-C,

Fig. 6 shows a formwork element with a recess body and a pigtail anchor,

Fig. 7 shows a schematic representation of the tension lock according to the invention without insertion openings in the conically converging side walls and without the adapter,

Fig. 8 shows a view of the tension lock without the adapter in a welded design,

Fig. 9 shows a schematic representation of the tension lock according to the invention without the adapter for illustrating the dimensions,

Fig. 10 shows a schematic representation of an adapter for the tension lock according to the invention,

Fig. 1 1 shows a schematic representation of the tension lock according to the invention with the adapter installed,

Fig. 12 shows a top view of the tension lock according to the invention and the adapter in the non-installed state,

Fig. 13 shows a sectional view of the tension lock according to the invention with the adapter installed and a fastening device.

Fig. 1 shows a schematic representation of tension lock 1 according to the invention for joining prefabricated concrete elements 10 (see Fig. 13). As can be seen from Fig. 1 , tension lock 1 is substantially shell-shaped and has a receiving space 2 which is accessible from the outside via an access opening 9. Tension lock 1 additionally comprises two passage openings 3, 4 (being offset by 90°) disposed opposite to each other and opening into receiving space 2 for the insertion of fastening devices, e.g. screws 13 (see Fig. 13). In the present embodiment, a passage opening 3 is designed as a slot which is open on one side and opens into access opening 9. The other passage opening 4 is in the present embodiment designed as an elongated hole. The slot and the elongated hole are formed in oppositely disposed planar side walls 7, 8.

The number, design and arrangement of passage openings 3, 4 shown in the embodiment are only by way of example. For more effective mounting and better compensation of the connection points provided with manufacturing-related tolerances, planar side walls 7, 8 of tension lock 1 can. for example, each therefore be provided with a slot and slot and/or an elongated hole, respectively, or with two elongated holes offset by 90°. Side walls 5, 6 are respectively formed straight and in a cross-sectional view conically converging. At the end at which side walls 5, 6 converge closest, they are joined to each other by a curved region 28 (Figure 1 1 ).

Conically converging side walls 5, 8 are in the present embodiment designed as being integrally formed and have a U-shaped cross-section. However, the integrally formed design of conically converging side walls 5, 6 is only by way of example. Alternatively, conically converging side walls 5, 6 can also be designed as individual side walls which are not joined to each other. A V-shaped cross-section is also conceivable.

Insertion openings 20, presently being formed as recesses, are in order to reduce weight provided in conically converging side walls 5, 6 and in base 21 of tension lock 1 (see Fig. 2). The arrangement and the number of insertion openings 20 depends on the respective circumstances.

Due to conically converging side walls 5, 6, the required clearance for the rotary motion of a tensioning tool (not shown) for creating a screw connection is given.

Tension lock 1 is, at least in sections, made of metal and/or preferably of cast steel and/or steel. Preferably, the steel has a tensile strength of at least 400N/mm 2 to 800N/mm 2 , preferably 450N/mm 2 to 780N/mm 2 , particularly preferably 500N/mm 2 to 750N/mm 2 , and is preferably made of non-corroding steel. High load-bearing cast steel guarantees the absorption of the tensile and transverse forces arising and furthermore ensures economic and low-cost production of tension lock 1. Due to its geometrical shape and arrangement of passage openings 3, 4 for the screw connections, which can also be regarded as recesses, tension lock 1 according to the invention absorbs the tensile and transverse forces arising for the connection to be established with the respective prefabricated concrete elements 10 (see Fig. 13). Instead of screw connections, other suitable connections are also possible.

Fig. 2 shows a top view of tension lock 1. Fig. 3 shows insertion opening 20 particularly well. Fig. 3 as well shows insertion opening 20 particularly clearly. Fig. 4 shows planar side wall 8 with elongated hole 4, and Fig. 5 shows planar side wall 7 with slot 3. In addition, the opening angle of side wall 7 is in Fig. 5 given at 38.8°. This angle is only to be considered as an example and can be adapted to the circumstances.

Fig. 6 shows a formwork element 17 with a recess body 15 and pigtail anchor 16.

Fig. 10 illustrates an adapter 23 according to the invention without tension lock 1.

Adapter 23 on its side facing access opening 9 of tension lock 1 in sections comprises a planar bearing surface 24. Furthermore, adapter 23 comprises an opening 25 for inserting fastening devices 13. This opening 25 is in the installed state arranged opposite to base 21 of tension lock 1. At its side facing the insertion opening 20 in base 21 of tension lock 1 , the adapter is at least in sections convex, preferably barrel-shaped, so that a positive fit arises at least in sections between tension lock 1 and adapter 23.

The curvature is in Fig. 10 marked with reference numeral 26.

In the embodiment illustrated in Fig. 10, opening 25 in adapter 23 is an elongated hole 25. Alternatively, opening 25 can also be designed as a slot. The dimensions of opening 25 shown in Fig. 10 are only to be regarded as being by way of example. Depending on the circumstances, the dimensions of opening 25 and also its shape can vary.

The longitudinal axis of opening 25 in adapter 23 extends parallel to the longitudinal axis of curvature 26 of adapter 23. Rotation of adapter 23 in tension lock 1 is thereby possible. In this way, tolerances can be compensated for and easier insertion of fastening device 13 can be achieved.

At the corners of planar bearing surface 24, holding devices 27 are mounted which extend upwardly, i.e. in the installed state of adapter 23 in the direction of access opening 9 of tension lock 1. The arrangement and the number of holding devices 27 are only to be regarded as being by way of example. Holding devices 27 can also be omitted. Easier insertion of adapter 23 into tension lock 1 and an easier removal of adapter 23 from tension lock 1 are made possible by holding devices 27.

It has proven to be advantageous to have the width B and the height A of tension lock 1 have the same length, or the width B is preferably at least 15% less than the height A. The dimensions of tension lock 1 are shown in Fig. 9. It is advantageous to have the height H of adapter 23 be at least preferably about one-third of the dimension C of tension lock 1 from curved region 28 to access opening 9. Particularly high stability is obtained with such dimensions, but the dimensions can be adapted to the respective requirements.

Fig. 1 1 shows a tension lock 1 according to the invention with an adapter 23 for joining prefabricated concrete elements 10. Tension lock 1 is formed substantially shell-shaped and comprises two side walls 7, 8 which are substantially planar and disposed parallel opposite to each other. Furthermore, tension lock 1 comprises two sidewalls 5. 6 which in a cross- sectional view conically converge. At the end where side walls 5, 6 converge the most, they are joined to each other by curved region 28. Receiving space 2 is accessible via access opening 9. Passage sections 3, 4 are disposed in planar side walls 7, 8 offset by 90°.

Side walls 5. 8 are formed to be straight and have a uniform wall thickness so that the cross- section is U-shaped. Tension lock 1 has an insertion opening 20 which is not visible in Fig, 1 1 and which is formed in base 21 of tension lock 1 opposite to access opening 9. Adapter 23 with its curvature 26 rests at least in sections on the side of curved region 28 of tension lock 1 that is located in receiving space 2. Planar bearing surface 24 of adapter 23 is there facing access opening 9 of tension lock 1. A positive-fit connection is in this manner given at least in sections between tension lock 1 and adapter 23. Opening 25 of adapter 23 is arranged opposite to insertion opening 20 in base 21 of tension lock 1 for the insertion of fastening devices 13 as shown, for example, in Fig. 16 (Fig. 13). Due to the barrel-shaped design of adapter 23, the latter can be moved in the tension lock and adapted to the insertion direction of fastening device 13, so that easier insertion of fastening device 13 is possible. Due to the planar bearing surface 24, fastening device 13 is easier to fasten and also the use of, for example, a washer 12 is enabled.

The opening area of opening 25 in adapter 23 is preferably smaller than the opening area of insertion opening 20 in base 21 of tension lock 1 . In this way, there is a certain clearance when mounting fastening device 13 and reliable attachment of fastening device 13 in tension lock 1 is at the same possible.

Like the tension lock, adapter 23 can preferably have a tensile strength of 400 N/mm 2 to 800 N/mm 2 , preferably 450 N/mm 2 to 780 N/mm 2 and particularly preferably 500 N/mm 2 to 750 N/mm 2 .

Tension lock 1 and adapter 23 can have the same tensile strength. However, this is not absolutely necessary. Depending on the requirements, adapter 23 and tension lock 1 can also have different tensile strengths. Tension lock 1 and/or adapter 23 can at least in sections be made of annealed cast iron or of spherulitic graphite cast iron. Tension lock 1 and adapter 23 can therefore be made of the same material. However, it is also conceivable to have adapter 23 and tension lock 21 be made of different materials. Other solid materials from annealed cast iron or spherulitic graphite iron are also conceivable.

Fig. 14 (Fig. 12) shows a top view of tension lock 1 without adapter 23 being installed. Adapter 23 is shown next to tension lock 1 . It is in this view clearly visible that the opening area of opening 25 in adapter 23 is smaller than the opening area of insertion opening 20 in base 21 of tension lock 1.

Fig. 13 shows a sectional view of tension lock 1 according to the invention with adapter 23 being inserted and fastening device 13 being inserted. The longitudinal axes of two of the three fastening devices 13 are in this figure arranged substantially parallel to one another and the longitudinal axis of the third fastening device 13 is arranged substantially perpendicular thereto. The sectional view is in Fig. 13 for a better view shown as a line grid.

The construction kit according to the invention for joining prefabricated concrete elements 10, which can also be referred to as a tensioning system, comprises tension lock 1 according to the invention with adapter 23 and at least one anchor, preferably a pigtail anchor 16 and at least three fastening devices 13, where the longitudinal axes of fastening devices 13 in passage sections 3, 4 in planar side walls 7, 8 extend substantially parallel to one another, and the longitudinal axis of fastening device 13 in opening 25 of adapter 23 extends substantially perpendicular thereto. Furthermore, the construction kit can comprise at least one recess body 15, as described above. Pigtail anchor 16 is intended to be inserted into prefabricated concrete element 10. If a particularly tight connection between the prefabricated concrete elements 10 is required, then the construction kit can additionally be provided with a sealant 14, as for example the above-described sealing tape.

This sealing tape 14 is prior to joining prefabricated concrete elements 10 inserted between sides 18, 19 of prefabricated concrete elements 10 to be joined.

According to a method for joining prefabricated concrete elements 10, prefabricated concrete elements 10 each having at least one recess 1 1 are assembled in such a manner that recesses 11 are disposed opposite to prefabricated concrete elements 10 to be joined. An anchor, e.g. the above-described pigtail anchor 16, is ideally inserted into prefabricated concrete element 10.

Thereafter, tension lock 1 according to the invention with adapter 23 is inserted into recesses 1 1 of prefabricated concrete elements 10. Thereupon, screws 13 are inserted through access opening 9 into receiving space 2 and are through a respective passage section 3, 4, such as slot 3 or elongated hole 4 of tension lock 1 as well as opening 25 of adapter 23 and insertion opening 20, inserted into the anchor. Due to the design of slot 3 or of elongated hole 4, respectively, and opening 25 as well as of insertion opening 20 in base 21 of tension lock 1 , effective assembly and a better compensation possibility of connection points provided with manufacturing-related tolerances is possible.

Tension lock 1 is subsequently fixated with screws 13 and washers 12. Thereafter, screws 13 are rotated, e.g. with a ring ratchet or with a torque wrench, respectively.

This sequence is only by way of example and can be altered. It is conceivable e.g. that the anchors are not already installed into the prefabricated concrete elements in the factory, but are inserted at the construction site.

If a connection impermeable to water and/or gas is desired, then it is necessary to insert sealant 14 between sides 18. 19 of prefabricated concrete elements 10 to be joined. The use of a sealing tape 14, e.g. RubberElast® is particularly advantageous. The present invention relates to a tension lock 1 , which can also be referred to as a tensioning device, for the assembly of a permanent connection of prefabricated concrete elements 10 or similar structural elements made of other suitable materials. This tension lock 1 , due to its specific shape and the fastening devices arranged, such as, for example, screw devices, in particular screws, enables clamping as well as rapid, efficient assembly and a permanent structural connection of prefabricated concrete elements 10, e.g. prefabricated ferroconcrete elements. The specific geometric shape of tension lock 1 , with screw connection and pigtail anchors 16 or anchor sleeves, respectively, inserted into prefabricated concrete elements 10, enables assembly and permanent joining of concrete elements 10 or prefabricated concrete elements 10, respectively. Tension lock 1 according to the invention therefore greatly facilitates the assembly of prefabricated concrete elements 10, promises high precision in the production and significant time-saving at the construction site.

Possible areas of application include the strong and permanent joining of floor and ceiling panels, sandwich elements, double walls and angle supports.

In addition to the use as a structural joining element, tension lock 1 is provided for the regular and permanent transmission of tensile and transverse forces under predominantly static loads.

The tensioning system consists of a tension lock 1 according to the invention with an adapter 23. Fastening devices 13, and at least one anchor 16, e.g. pigtail anchors 16, which is provided to be inserted into prefabricated concrete elements 10. Two versions are conceivable that can be loaded with tensile forces of up to 50 kN or 100 kN. This specification is only by way of example. Depending on the circumstances, versions with lower or higher tensile forces are also conceivable.

In particular prefabrication can be effected in a customized manner at the factory for the prefabricated concrete elements. Exact positioning of the pigtail anchors or anchor sleeves, respectively, as well as the formation of the recess is effected by way of the magnetic recess bodies in only one step.

Sealing tape 14, e.g. RubberElast®, is during assembly simply pressed onto the concrete in the area of the joint. This sealing tape 14 is ideally self-adhesive. A protective strip on sealing tape 14 is removed and the next concrete element 10 is pressed against sealing tape 14.

The tension lock is inserted and fixed with the screws and washers.

Thereafter, the screws are firmly tightened with a ring ratchet or a torque wrench.

The tensioning system offers a wide range of applications, such as the installation of angle supports used in road construction and underground engineering, in gardening and landscaping as well as coastal protection areas, as well as the connection of floor slabs, shaft sections, ceiling and wall elements and many other structural prefabricated concrete elements.

The advantages of the tension lock according to the invention lie in the efficient and rapid joining of prefabricated concrete elements 10, the tensioning of prefabricated concrete elements 10 without additional materials and special aids. In addition, the tension lock can be combined with all approved anchor systems and has a low own weight. Complex customized solutions are dispensed with using the tension lock according to the invention. Precise positioning in the manufacturing process is possible due to the magnetic technique (recess body 15 magnetically attachable to formwork element 17). Furthermore, the use of the tension lock provides the option of examining the prefabricated concrete elements connections for maintenance purposes with little effort. As a result, an operational connection of the joined prefabricated concrete elements can be ensured over long periods of time.

The use of sealing tape 14, e.g. RubberElast®, ensures extremely high impermeability to water and gas, very good bonding due to adhesion, fast processing where no tools are required. The connection is waterproof immediately after installation. In addition, the sealing tape is flexible even at low temperatures, is resistant to acids, base, salt and weathering.

Fig. 8 shows tension lock 1 in an embodiment of a welded configuration. Due to the forces of the elements applied that act upon the tension lock and the loads resulting therefrom, the design is adapted by changing the wall thicknesses of the individual elements. The two conically converging side walls 5, 6 are joined to form a trough shape. The tension lock can there be easily fabricated during the production process by inserting side walls 7, 8 and welding. Side walls 7, 8 have a greater wall thickness than conical side walls 5, 6. By joining prefabricated concrete elements 10, side walls 7, 8 are subjected to bending so that shear stresses occur within side walls 7, 8. This area can be specifically reinforced by a thickening. Furthermore, the thickening helps to prevent deformations caused by the generation of element stresses following the welding.

In summary, the tension lock according to the invention provides the possibility of joining prefabricated concrete elements to each other in a manner saving costs and time. The tension lock and the adapter can there be produced in different configurations, where a welding design, an embodiment by thermoforming, or an embodiment as composite material, possibly with adhesive technology, can advantageously be used. The materials at issue can also be cast steel materials, but also annealed cast iron, spherulitic graphite cast iron or steel, where particularly stainless steel, preferably non-corroding steel, can be used. Higher mechanical strength of the tension lock can be obtained with these configurations, as well as improved corrosion resistance. With theses configurations, the use of the tension lock according to the invention is also possible in earthquake-prone regions. The use of different and variably modifiable recess bodies is possible with the method for producing the prefabricated concrete elements.

By use of the adapter, not only adjacently disposed prefabricated concrete elements can be joined to each other, but also prefabricated concrete elements, which are arranged, for example, at a right angle to one another. The barrel-shaped design of the adapter makes it possible to move the adapter during assembly and in particular when inserting the fastening device into the opening of the adapter. The insertion of the fastening device into the opening of the adapter is thereby facilitated. Any inaccuracies or tolerances possibly existing can be compensated for. In addition, the adapter self-adapts during the attachment. The tension lock according to the invention with the adapter can therefore be used more universally than a conventional tension lock without an adapter.