EP3754134A1 - Tensioning device for corner formwork - Google Patents

Abstract

The invention relates to a clamping device (10) for a corner shuttering, comprising an inner angle element (11), an outer angle element (12) and a connecting means (13) in order to brace the inner angle element (11) and the outer angle element (12) against each other and at an angle to connect mutually standing formwork elements (1, 2). The clamping device (10) is characterized in that the connecting means (13) is a flexible tension element.

Description

The invention relates to a tensioning device for a corner shuttering, comprising an inner corner element, an outer corner element and a connecting means to brace the inner corner element and the outer corner element against each other and to connect shuttering elements that are at an angle to each other.

In order to cast outside or inside corners out of concrete, rigid angled formwork elements are known which have to be fixed in the corner area from inside or outside until the concrete has hardened. The provision of prefabricated angled formwork elements on construction sites in addition to the otherwise flat formwork elements represents an additional logistical effort and cost of materials.

As an alternative, clamping devices of the type mentioned are known, with the help of which two flat formwork elements, e.g. Formwork boards can be joined together at an angle so that they form an angular formwork element.

For example, the document shows DE 23 30 586 A1 Inside and outside angle elements made of steel, which can accommodate two formwork boards at an angle to each other in a corner area, which can be braced against each other in order to connect them together so that they can withstand the pressure of the liquid concrete. For this purpose, a spindle is welded to the outer angle element in the direction of the bisector, which is guided through a hole in the inner angle element. With the help of the spindle and an attached nut, the angle elements are then pulled towards each other in order to clamp the two shuttering boards.

Due to the design, the formwork boards in this device are far apart in the corner area, so that the clamping device must extend over the entire length of the formwork boards in the corner area, otherwise concrete would run out between the formwork boards. In addition, such a system is expensive because of the material used and is therefore not suitable for lost formwork.

The pamphlet DE 29 2 15 733 A1 shows a similar system with inner and outer angles, in which the corner area of two formwork boards is surrounded by vertical corner timbers that have been milled accordingly. Threaded rods with washers and nuts are passed through the corner timbers as connecting means in order to brace the inside and outside angle elements against each other.

Due to the simpler design and thus lower costs, this system can in principle also be used for lost formwork. However, the system is complex to use, especially since corresponding vertical corner timbers have to be appropriately profiled and drilled to pass through the threaded rods. Tensioning with the help of the threaded rods, in particular placing washers and nuts, is also time-consuming.

It is therefore an object of the present invention to create a clamping device of the type mentioned at the outset, which can be manufactured inexpensively and therefore can also be used for lost formwork and which can be used easily, quickly and flexibly on the construction site.

This object is achieved by a tensioning device for corner cladding with the features of the independent claim. Advantageous refinements and developments can be found in the dependent claims.

A tensioning device according to the invention of the type mentioned at the outset is characterized in that the connecting means is a flexible tension element.

Instead of the spindle or threaded rod known from the prior art, a traction means is used that requires much less material than the mentioned spindles or threaded rods and is correspondingly inexpensive.

A strap, cord or band, for example, which can (only) be subjected to tensile loads, can be used as the pulling means. The term "cord" is to be understood in the context of the application regardless of the material used. In this sense, a wire or wire rope made of metal can also represent a cord. The cross section of the pulling means can be round or approximately round like a cord, or flattened like the band or the tab. Compared to a threaded rod, the elements mentioned require at least one Direction significantly smaller cross-sectional width, so that the formwork elements, between which the traction device is passed, can protrude so close to one another in the corner area that concrete is prevented from flowing through. For this reason, the tensioning device according to the invention need not extend along the entire length of the corner cladding. Rather, it is possible to use individual clamping devices which each extend only a few centimeters in the longitudinal direction of the corner cladding and which are used in the required number at a distance from one another. In this way, too, the formwork elements can be connected with little use of material.

In an advantageous embodiment of the clamping device, the connecting means is formed integrally with the inner angle element or the outer angle element. In this way, manufacture can be simplified. The connecting means can preferably be releasably fastened to the inner angle element and / or the outer angle element so that the formwork can be opened again after the concrete has hardened and outer formwork elements can be removed and reused.

In a further advantageous embodiment of the clamping device, the inner angle element and / or the outer angle element has a feed-through opening for the connecting means. The connecting means is advantageously already attached to one of the angle elements, possibly integrally formed therewith, and is attached to the other of the angle elements by being guided through this passage opening and thus on the part of the user, i.e. on the side facing away from the concrete to be filled, can be gripped, tensioned if necessary and conveniently attached to the element.

The connecting means is particularly preferably a tab which is provided with a toothing, a latching tongue which engages in the toothing being formed in the region of the lead-through opening. The toothing of the tab and the locking tongue thus work together like a cable tie, so that the two angle elements can only be moved in one direction, namely towards one another and not away from one another. In this way, the two angle elements can be braced against one another simply, quickly and without tools. A gripping eyelet can also be formed at the end of the tab, into which a finger can be inserted in order to be able to clamp the angle elements against one another.

In a further advantageous alternative embodiment of the tensioning device, the connecting means is a cord, an anchor being fastened or formed at a free end of the cord, with which the cord is fastened to one of the angle elements. The other angle element can have a winding web in the area of the lead-through opening, on which the cord can be fixed. In order to simplify the fixing, the winding web can have at least one clamping incision into which the cord can be clamped.

In a further advantageous alternative embodiment of the tensioning device, the inner angle element and / or the outer angle element and / or the connecting means are made of plastic, in particular polyamide. The clamping device can e.g. can be produced simply and inexpensively in an injection molding process.

Furthermore, contact surfaces with which the inner angle element and / or the outer angle element rest on the formwork elements can advantageously be provided with a profiling and / or with a stopper surface in order to fix the formwork elements as securely as possible. A stopper surface is a surface with an increased static friction value compared to the base material of the angle elements. For profiling, e.g. Profile webs, in particular with a sawtooth profile, be formed.

Fig. 1

eine isometrische Ansicht von Schalungselementen mit Spannvorrichtungen in einem ersten Ausführungsbeispiel;

Fig. 2

eine vergrößerte isometrische Darstellung einer Spannvorrichtung nach Fig. 1;

Fig. 3, 4

jeweils eine teilgeschnittene Darstellung von Teilen der Spannvorrichtung gemäß Fig. 2;

Fig. 5

eine isometrische Ansicht von Schalungselementen mit Spannvorrichtungen in einem zweiten Ausführungsbeispiel;

Fig. 6

eine Draufsicht auf eine Spannvorrichtung nach Fig. 5; und

Fig. 7

die Spannvorrichtung gemäß Fig. 6 in verschiedenen isometrischen Detailansichten.

The invention is explained in the following on the basis of exemplary embodiments with the aid of figures. The figures show:

Fig. 1

an isometric view of formwork elements with clamping devices in a first embodiment;

Fig. 2

an enlarged isometric view of a clamping device according to Fig. 1 ;

Fig. 3, 4

in each case a partially sectioned representation of parts of the clamping device according to FIG Fig. 2 ;

Fig. 5

an isometric view of formwork elements with clamping devices in a second embodiment;

Fig. 6

a plan view of a jig according to Fig. 5 ; and

Fig. 7

the clamping device according to Fig. 6 in different isometric detail views.

In Fig. 1 two formwork elements 1, 2 are shown by way of example, which are arranged at right angles to one another and are held in the position shown by clamping devices 10 according to a first exemplary embodiment.

The space in which the smaller interior angle of approximately 90 ° lies between the two formwork elements 1, 2 is designated as the interior area 3, whereas the area of the exterior angle of approximately 270 ° between the formwork elements 1, 2 is referred to as the exterior area 4. The clamping device shown is particularly suitable for producing a concrete outer corner in which the inner area 3 of the formwork is filled with concrete.

In the example shown, the formwork elements are flat and solid boards. Due to the great flexibility with regard to the thickness of the formwork elements 1, 2 of the clamping device 10, however, these can also be used for other formwork elements, in particular also for example for thicker frame formwork elements.

The clamping device 10 of the first embodiment is shown in FIG Fig. 2 enlarged in an isometric view and in the Figures 3 and 4 reproduced in various partially cut representations.

It has an interior angle element 11 with two legs 111, 112 which, in the example shown, are at an angle of 90 degrees to one another. The inner angle element 11 lying in the inner area 3 between the shuttering boards 1, 2 rests with the outer sides of the legs 111, 112 on the shuttering elements 1, 2.

In order to fix the formwork elements 1, 2 as well as possible, the outside of the legs 111, 112 is profiled, in the present case by means of profile webs 113 formed on the surface, which have a sawtooth-like profile.

The connecting means 13 is fastened integrally to the inner angle element 11, for example in that the inner angle 11 and the connecting means 13 are jointly produced in one piece from plastic in an injection molding process. When Material can be used, for example, polyamide, which is elastic and has a high tensile strength. In this exemplary embodiment, the connecting means 13 is designed as a tab and is also called tab 13 below for the sake of simplicity of illustration.

From the outside, i.e. in the outer area 4, the outer angle element 12 is placed on the corner formed by the two formwork elements 1, 2. The outer angle element 12 also has two legs 121, 122, the inner sides of which are at an angle of 90 ° to one another. The inside resting on the formwork elements 1, 2 is provided with a profile which, similar to the internal angle element 11, is formed by profile webs 123 which have a sawtooth-shaped profile. The outer angle element 12 is also preferably manufactured in one piece in an injection molding process, for example again from polyamide.

In the connection area of the two legs 121, 122, a feed-through opening 124 is formed in the outer angle element 12, through which the tab 13 is inserted. The outer angle element 12 is then, as in FIG Fig. 1 is shown, pushed onto the formwork elements 1, 2. The tab 13 has a toothing 131 which cooperates with a latching tongue 125 which is arranged in the feed-through opening 124 of the outer angle element.

The toothing 131 of the tab 13 and the latching tongue 125 work together as in a cable tie, so that the two angle elements 11, 12 can only be moved in one direction, namely towards one another and not away from one another. The surface of the locking tongue 125 can also be provided with a toothing, as in FIG Fig. 4 can be seen in the enlargement on the left.

A gripping eyelet 132 is formed at the end of the tab 13, into which a finger can be inserted in order to pull the inner angle element 11 in the direction of the outer angle element 12 when this is pressed onto the formwork elements 1, 2. Due to the elasticity of the material used for the tab 13, a high tension force can be built up between the inner and outer angle elements 11, 12. By means of a plurality of spaced apart clamping devices 10, formwork elements 1, 2 of any length can be connected to one another safely and quickly in the corner area. The connection can be established quickly and without tools.

In order to remove the formwork elements after the concrete has hardened, the locking tongue 125 can be lifted with a screwdriver or a specially shaped tool, for example, in order to release the locking connection between the tab 13 and the outer angle 12. The outer angle 12 can then be removed and reused if necessary.

After removing the formwork elements 1, 2, the inner angle element 11 surrounded by the concrete is left in the concrete and the outwardly protruding tab 13 is cut off at the concrete edge. Thus, the clamping device can be removed easily and without great dismantling effort.

In an alternative configuration of the first exemplary embodiment, the tab 13 can also be fastened integrally on the outer angle element 12, whereas a feed-through opening and a latching tongue are located on the inner angle element 11. In the embodiment, the clamping device 10 is then particularly suitable for inner corners made of concrete, i.e. for a situation in which concrete is poured into the outer area 4 of the formwork (cf. Fig. 1 ).

In the Figures 5 to 7 Another embodiment of a clamping device 10 is shown. Fig. 5 initially admits Fig. 1 an isometric representation of two formwork elements 1, 2, which are connected to one another with two clamping devices 10. Fig. 6 shows the clamping device 10 in a plan view and FIG Fig. 7 shows the clamping device 10 in two different isometric views (left side of the figure) with enlarged cutouts (right side of the figure).

With regard to the basic structure and the choice of material, the inner and outer angle elements 11, 12 in particular correspond to those of the first exemplary embodiment, to which reference is hereby made explicitly.

The difference is in the second embodiment Figures 5 to 7 the connecting element 13, which is formed in this embodiment by a cord. For the sake of simplicity, the connecting element 13 is also referred to as a cord 13 in connection with this exemplary embodiment.

The cord 13 can consist of one or a plurality of plastic fibers, in particular polyamide fibers. As mentioned at the beginning, the term “cord” is also to be understood as a wire or a wire rope made of metal.

As from the detailed drawings of the Fig. 7 As can be seen, in the illustrated embodiment, one end of the cord 13 is provided with an anchor 133, here spherical. In the example shown, the anchor is used on the side of the inner angle 11. The free end of the cord 13 is passed through the feed-through opening 124 of the outer angle element 12 and, as described in connection with the first exemplary embodiment, the inner and outer angle elements 11, 12 are braced against one another by pulling on the cord 13.

In order to keep the tensioning device 10 in the tensioned state, a winding web 126 is formed in the outer angle element 12, onto which the cord 13 can be wound. For this purpose, the winding web 126 has clamping incisions 127 into which the cord 13 is clamped, so that the cord 13 is fixed and maintains its tension.

Like the detail drawing in Fig. 7 shows, a comparable winding web 114 is also formed on the inner angle element 11. This also has clamping incisions 115 in order to be able to fix the cord 13 there. The formation of winding webs 114, 126 on both angled elements 11, 12 makes it possible to use the armature 133 alternatively on the side of the outer angle 12 and to fix the free end when covering on the winding web 114 of the inner angle element. Cord 13 can also be used from a reel and without the anchor 133 by attaching it to the corresponding winding web 114, 126 on both sides.

Another difference to the first embodiment is that in the area of the support surfaces of the legs 111, 112 of the inner angle element 11 and the legs 121, 122 of the outer angle element 12, in addition to the profile webs 113, 123, areas are provided with a softer elastic material, for example polyurethane, and represent stopper surfaces 116, 128. Due to a high coefficient of friction, these also ensure that the formwork elements 1, 2 are held securely to one another by the clamping device 10. Such stopper surfaces 116, 128 can of course also be present in the first exemplary embodiment.

In the top view of the Fig. 6 the angles α and β spanned by the inner angle element 11 and the outer angle element 12 are shown. In this embodiment, the angle α spanned by the inner angle element 11 is greater than 90 °, here 95 ° as an example, and the angle spanned by the outer angle element 12 is smaller than 90 °, here 85 ° as an example. The clamping device 10 is used for formwork elements 1, 2 which are at right angles to one another. By making the outer angle element 12 smaller than 90 ° and the inner angle element 11 larger than 90 °, an additional clamping effect of the formwork elements 1, 2 between the legs 111, 112 and 121, 122 is achieved. When tensioning the connecting element 13, both angle elements 11, 12 are deformed to an angle of 90 ° and exert additional tensioning force. This configuration can also be used in the first exemplary embodiment Figs. 1 to 4 can be used.

The examples shown in the context of the application are each designed for formwork elements 1, 2, which should be at right angles to one another. It goes without saying that the clamping devices 10 shown can also be designed for formwork in which the formwork elements 1, 2 are arranged at a different angle to one another. Even an angle of 180 ° would be conceivable, so that formwork elements can be connected to one another in one plane with the clamping devices shown.

Reference number

1, 2

Formwork element

3

Indoor

4th

Outdoor area

10

Jig

11

Interior angle element

111, 112

leg

113

Profile web

114

Winding bridge

115

Clamping incision

116

Stopper surface

12

Exterior angle

121, 122

leg

123

Profile web

124

Feed-through opening

125

Locking tongue

126

Winding bridge

127

Clamping incision

128

Stopper surface

13

Connecting element (strap, cord)

131

Interlocking

132

Handle loop

133

anchor

α, β

angle

Claims (14)

Clamping device (10) for corner cladding, comprising an inner angle element (11), an outer angle element (12) and a connecting means (13) in order to clamp the inner angle element (11) and the outer angle element (12) against one another and formwork elements ( 1, 2) to be connected to each other, characterized in that
the connecting means (13) is a flexible tension element. Clamping device (10) according to Claim 1, in which the connecting means (13) is non-detachably attached to the inner angle element (11) or the outer angle element (12). Clamping device (10) according to Claim 2, in which the connecting means (13) is formed integrally with the inner angle element (11) or the outer angle element (12). Clamping device (10) according to one of Claims 1 to 3, in which the connecting means (13) can be releasably fastened to the inner angle element (11) and / or the outer angle element (12). Clamping device (10) according to one of Claims 1 to 4, in which the inner angle element (11) and / or the outer angle element (12) has a feed-through opening (124) for the connecting means (13). Clamping device (10) according to claim 5, in which the connecting means (13) is a tab which is provided with a toothing (131), and in which a latching tongue (125) is formed in the region of the feed-through opening (124), which into the Toothing (131) engages. Clamping device (10) according to Claim 6, in which a grip eyelet (132) is formed at a free end of the tab. A tensioning device (10) according to claim 5, wherein the connecting means (13) is a cord. Tensioning device (10) according to Claim 8, in which an anchor (133) is fastened or formed at a free end of the cord. Clamping device (10) according to Claim 8 or 9, in which the inner angle element (11) and / or the outer angle element (12) has a winding web (114, 126) for securing the cord in the region of the feed-through opening (124). Tensioning device (10) according to Claim 10, in which the winding web (114, 126) has at least one clamping incision (115, 127) into which the cord can be clamped. Clamping device (10) according to one of Claims 1 to 11, in which the inner angle element (11) and / or the outer angle element (12) and / or the connecting means (13) are made of plastic, in particular polyamide. Clamping device (10) according to one of Claims 1 to 12, in which contact surfaces with which the inner angle element (11) and / or the outer angle element (12) rests on the formwork elements (1, 2) have a profile and / or a stopper surface (116, 128) is provided. Clamping device (10) according to Claim 13, in which profile webs (113, 123), in particular with a sawtooth profile, are formed on the contact surfaces for profiling.

Images