Abstract:
The invention relates to a slab formwork system comprising a plurality of formwork elements ( 98 ) which have on their underside girders ( 2 ) which can be coupled to heads ( 28 ) of vertical supports ( 90 ), in which slab formwork system the head of a vertical support has a lifting lock ( 44 - 51; 87 ) fixing a girder of a formwork element in the vertical direction. In addition, the head of a vertical support has fixing elements ( 52 - 66 ) which prevent a movement of the grider in its longitudinal direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/EP2007/002825, filed Mar. 29, 2007, and which claims the benefit of German Patent Application No. 10 2006 015 348.0, filed Apr. 3, 2006, the disclosures of both applications being incorporated herein by reference. 
     The invention relates to a slab formwork system having a plurality of formwork elements which have carriers couplable to heads of vertical supports at their lower side. 
     A slab formwork system of this type is known from document EP 0 130 425 A1. This system consists of formwork panels at whose lower sides C-shaped carriers are arranged which can be hooked with a head of a vertical support on a substantially vertical alignment of the formwork panels, whereupon the formwork panels can be pivoted into a horizontal position while maintaining the hook connection. To avoid a displacement of the carriers in their longitudinal direction relative to the head of the vertical support, the base section of the C-shaped carrier is provided with an opening into which a fixing element can engage which is fixedly connected to the head of the vertical support. 
     The fact is disadvantageous in the known slab formwork system that formwork elements mounted on the vertical supports can easily release from the vertical supports on a corresponding exertion of force, which can cause a considerable risk of an accident. 
     SUMMARY OF THE INVENTION 
     An object of the present invention can be seen in further developing a slab formwork system of the kind explained above such that a reduced risk of accident results. 
     This object is satisfied by embodiments described herein, and in particular in that the head of a vertical support has a lift-off safeguard fixing a carrier of a formwork element in the vertical direction, with the head of a vertical support additionally having fixing elements which prevent a movement of the carrier in its longitudinal direction relative to the head. 
     It is ensured by the lift-off safeguard provided in accordance with the invention that a formwork element once coupled to a vertical support can no longer subsequently be released from the vertical support or be displaced in an unintended manner by a movement of the formwork element directed substantially upwardly or in the longitudinal direction of the carrier. This is in particular of advantage during the assembly or dismantling phase, that is, before or after the application of the concrete to the slab formwork system since, in specific situations, force components which are directed upwardly or in the longitudinal direction of the carriers can by all means act on regions of formwork elements coupled to vertical supports, the force components then, in accordance with the prior art, being able to result in an unwanted and frequently dangerous lifting off of the formwork elements from the vertical supports or in an unintended displacement of the formwork elements relative to the vertical supports. 
     The lift-off safeguard is preferably made as a first hook element which is firmly, but optionally releasably, connected to the vertical support and engages into a second hook element, which is formed at the carrier of the respective formwork element, in the assembled position of a formwork element. The lift-off safeguard in accordance with the invention can thus be manufactured economically and efficiently, with it additionally being achieved that the effect of the lift-off safeguard can be realized solely by a hooking together of the first and second hook elements without parts or tools to be handled separately being necessary for this purpose. This also has a corresponding positive effect on the dismantling of the slab formwork system in accordance with the invention. 
     The carriers of the formwork elements can have an at least regionally C-shaped cross-section which has two limbs extending away from a base section, with one of these two limbs being designed as a second hook element. Since this second limb is anyway present with a C-shaped carrier, the second hook element can in this case be realized practically without any economic effort. 
     The limb of the carrier designed as a second hook element can furthermore form a support surface at least sectionally for the support of the carrier on a head of a vertical support so that this limb then has a dual function, which further increases the economy of the total arrangement. 
     The head of a vertical support can have fixing elements which each engage in a respective recess of the named support surface, with the recess being provided at the end of the support surface remote from the base section of the C-shaped carrier. It is particularly advantageous in this case if the first hook elements are formed at the fixing elements attached to the head of the vertical support. Such an embodiment will be explained in more detail within the framework of the description of the Figures. 
     It is particularly preferred if the carrier is couplable to the vertical support selectively in two directions offset by 90° to one another. 
     For example, when the recess for the fixing of the carriers in their longitudinal direction relative to the vertical support is not provided in the base section in accordance with the invention, but rather in the support surface, and there in the region remote from the base section, it becomes possible to arrange a plurality of fixing elements at the head of a vertical support such that a carrier can be fastened to the head of the vertical support in two directions offset by 90° with respect to one another. The variability of a slab formwork system in accordance with the invention is hereby increased with respect to known slab formwork systems in a manner such that the slab formwork system can be adapted in a respective ideal manner to individual circumstances by the selection possibility present on the attachment of formwork elements to a head of a vertical support. 
     Whereas, in accordance with the invention, the one limb of the carrier serves as a support surface and as a second hook element for the interaction with a vertical support, the other limb of the carrier can be made as a contact surface for a plurality of longitudinal members of a grid element onto which ultimately a sheathing can then be applied. Alternatively, the other limb can, however, also be made as a contact surface for a formwork panel, with in this case, unlike the use of a grid element, no further elements being located between the carrier in accordance with the invention and the formwork panel. 
     The carriers being used in accordance with the invention are preferably made as open sectional elements. Alternatively, however, closed sections can also be used. In the latter case, the described recess is likewise to be provided in the region of the respective support surface which is brought into contact with the vertical supports. 
     It is preferred for the support surface of the carrier respectively to have two or more recesses in each of the two mutually remote end regions of the carrier. This plurality of recesses then makes it possible to couple a carrier to a vertical support at different positions distributed over its length so that in turn different installation situations can be taken into account, but simultaneously the lift-off safeguard in accordance with the invention is realized at each selected position. 
     It is of advantage in this connection for at least two recesses of the support surface and two fixing elements of the head of a vertical support to be mutually spaced apart such that a simultaneous engagement of each of the two fixing elements is made possible in one each of the two recesses. In this case, the carrier can then either be installed at a vertical support via the named simultaneous engagement such that it terminates flush with its head, or an installation can be carried out such that the carrier projects over the head of the vertical support at both sides. When a corresponding number of pairs of recesses is provided, the carrier can project beyond the head of the vertical support over different lengths matched to the respective circumstances. These different lengths can be set simply by the selection of a suitable pair of recesses. 
     Even on the provision of at least two recesses in the support surface in one or both end regions of the carrier, it is possible to couple the carrier only via one of the two recesses with a fixing element of the head of a vertical support. This coupling variant is in particular selected when two carriers aligned with one another in the longitudinal direction should be fastened to a common head of a vertical support. 
     It is particularly preferred for the support surface to have at its end region remote from the base section an upwardly extending or angled lug, preferably extending parallel to the base section, which is provided with a cut-out, in particular of V shape, which is aligned with the recess provided in the support surface such that the cut-out and the recess merge into one another. In this case, the assembly of a formwork element at a vertical support is particularly simple since the correct positioning between the recess provided in the support surface and the fixing element of the respective head is facilitated by the named cut-out. Specifically, a carrier provided with the lug can be positioned above a head of a vertical support such that the cut-out present in the lug is located directly above the respective fixing element of the head, whereupon a lowering of the carrier onto the head can then take place in which the fixing element of the head is “threaded” into the cut-out of the lug. It is then achieved by a subsequent pivoting of the formwork element around a pivot axis extending parallel to the longitudinal axis of the carrier that the fixing element is introduced in a compulsory manner via the cut-out provided in the lug into the recess of the support surface corresponding therewith. The guiding of the fixing element to the recess of the support surface is in particular promoted by the V shape of the cut-out in the lug, with the width of the V-shaped cut-out growing as the spacing from the corresponding recess in the support surface increases. 
     It is furthermore advantageous for the lug to have two or more respective cut-outs of the named kind in each of the two mutually remote end regions of a carrier, the cut-outs being aligned in each case with corresponding recesses in the support surface. In this case, a corresponding cut-out can then be provided in the lug for each recess in the support surface so that the introduction of the fixing element into any desired recesses of the support surface is facilitated. 
     The lower side of the support surface preferably extends obliquely upwardly in its assembled position starting from the base section so that in particular the angle between the lower side of the support surface and the base section is smaller than 90° and preferably amounts to between 70° and 80°. It is achieved by this measure that the disassembly of a formwork element in accordance with the invention can be carried out without a problem since a pivoting away of a formwork element around an axis extending parallel to the carrier is not impeded by an upward movement of surface regions of the formwork element. This is in particular made clear on an observation of  FIGS. 5   a - c  explained below. 
     The vertical supports can in each case be provided with a support head which, in addition to a support plane extending perpendicular to the longitudinal extent of the respective vertical support, has fixing lugs angled therefrom for engagement into a respective recess of the support surface of a carrier. In this case, the fixing elements of the support head explained above are formed at the fixing lugs. The use of angled fixing lugs is advantageous in that an element can be used for the support head which is plate-shaped in the raw state and from which specific regions, preferably corner regions, can be bent upwardly as fixing lugs so that it is not necessary to apply separate fixing elements to the support head. Alternatively, however, it is also possible to make the support head as a cast part or a forged part or also to make it from plastic. 
     Eight fixing lugs, for example, can be provided per support head which in particular extend perpendicular to the support plane of the support head. 
     The support plane is preferably made substantially square or rectangular, with it then being able to have a respective two adjacent fixing lugs at each of its four corner regions, the fixing lugs each extending perpendicular to one another. 
     It is particularly advantageous if fixing elements which simultaneously have first hook elements are only formed at some of the plurality of fixing lugs. This means that the lift-off safeguard in accordance with the invention is only realized with a coupling of formwork elements to such fixing lugs whose fixing elements are made as first hook elements. If, however, such fixing lugs are used for the establishing of a connection between the formwork element and the vertical support whose fixing elements are not made as first hook elements, the lift-off safeguard in accordance with the invention is directly dispensed with. This can by all means be sensible and advantageous in specific applications, for example when it is necessary due to the given installation situation to place a formwork element onto the vertical supports associated with it from above so that in this case the first hook elements would collide with the second hook elements. In contrast, such a placing on taking place vertically from above becomes possible by the omission of the first hook elements. It is furthermore necessary in specific applications directly to strip a slab formwork at a specific point in the interior region in order to provide an access way in this manner, for example. In such a case, the formwork element to be stripped must be raised vertically upwardly, which would not be possible with a provision of first hook elements in the region of the vertical supports. 
     In this respect, it is sensible in order to maintain the flexibility, to provide both fixing lugs with first hook elements and fixing lugs without first hook elements, at least with specific support heads, since such a support head can then selectively be used such that a lift-off safeguard is achieved or actually such that a lift-off safeguard is deliberately avoided. It is particularly preferred in this connection if fixing lugs of a support head which extend in a first direction have fixing elements with first hook elements and if fixing lugs of the same support head which extend in a second direction extending perpendicular to the first direction have fixing elements which are free of first hook elements. 
     If then formwork elements which extend perpendicular to the first direction are coupled to such a support head, a lift-off safeguard is provided. If, however, the formwork elements extend perpendicular to the second direction, a lift-off safeguard is deliberately omitted. 
     It is particularly advantageous for the support head to have abutment regions for the rear side of the base section of a carrier remote from the limbs, with the abutment surfaces of the abutment regions in particular extending perpendicular to the support plane. With a carrier coupled to such a support head, regions of the fixing elements or fixing lugs are located, at the end of an assembly procedure in the recesses of the support surface made complementary thereto, with simultaneously the rear side of the base section being supported at the named abutment regions or coming to lie only at a small spacing from these abutment regions. These abutment regions thus prevent the fixing elements from being able to be moved out of the named recesses so that a reliable and defined fixing of a carrier to a support head is ensured here. 
     A total of eight abutment regions are preferably provided whose abutment surfaces in particular extend at an angle of 90° to the fixing lugs associated with them in each case. These eight abutment regions make it possible for a respective carrier to be able to be secured to the support head at four different positions, with two alignments of the carrier offset by 90° with respect to one another being possible in a horizontal plane at each of these four positions. Overall, therefore, four different carriers can be simultaneously arranged at a support head, with the alignment of each individual carrier being able to be selected individually. 
     The named abutment regions of the support head can be formed by separate abutment elements which are subsequently coupled to the support head. It is, however, preferred for four abutment regions to be formed by a section of the support head, or of the plate-shaped element from which the support head is made, bent into a substantially U shape and extending upwardly from the support plane. Two further abutment regions each can be formed in each case by one abutment lug bent upwardly out of the support plane. In this manner, the use of separate elements can be completely avoided and it is furthermore possible to produce the total support head from one single plate-shaped element. 
     The support head used in accordance with the invention can be connected to the vertical support associated with it either releasably or also fixedly. 
     It is particularly advantageous for the support head to be able to be coupled with a preferably substantially square head plate of a commercial vertical support, with the sizes of the head plate and the support head being able to be approximately the same with respect to one another. In this connection, the support head can be able to be pushed onto the head plate in a direction extending parallel to the head plate of the vertical support. The lower side of a support plane of the support head preferably comes to lie directly on the head plate of the vertical support in the assembled position such that no elements are needed which extend the vertical support beyond its head plate. The spacing between the upper side of the head plate of the vertical support and the support plane of the support head therefore corresponds, in this advantageous embodiment, substantially to the thickness of the material used for the support head. 
     When a releasable connection is provided, the support head can—as already mentioned—be pushed onto a vertical support in a direction extending parallel to its support plane and can be fixed there, in particular by means of a spring member held in the support head. This spring member then represents the only element of the support head which cannot be made from one plate-shaped base element. When made from plastic, the spring member can also be made integrally with the support head. 
     It is preferred in accordance with the invention for all support heads, vertical supports and/or end regions of the carriers used to be made the same with respect to one another. This then makes possible any desired combination variants and avoids the erroneous handling of individual components of the slab formwork system in accordance with the invention. 
     The assembly of a slab formwork system in accordance with the invention can be carried out particularly comfortably for a fitter when the vertical support and the carrier of a formwork element can be hooked to one another in such a position in which the formwork element and the vertical support include an angle smaller than 90°. It is preferred in this connection for the formwork element to extend substantially parallel to the respective vertical support or to the respective vertical supports on the establishing of this hook connection. 
     After the hooking together, a pivoting of the formwork element can then take place while maintaining the hook connection into such a position in which the formwork element and the vertical supports include an angle of approximately 90° so that the formwork element extends in a horizontal plane in which it can ultimately be used for the production of a concrete ceiling. The first and second hook elements in accordance with the invention are also then disposed opposite one another in this position so that the intended effect of a lift-off safeguard is present. 
     The formwork elements used in accordance with the invention can, for example, consist in each case of longitudinal members extending parallel to and spaced apart from one another which are fixedly connected to at least one cross member extending perpendicular thereto, with the upper sides of the longitudinal members forming a contact surface for a sheathing, the upper side of the cross-member or members contacting the lower side of the longitudinal members and the lower side of the cross member or members forming a support surface of the described type. In this case, the formwork elements in accordance with the invention therefore form grid elements which are first installed onto the vertical supports, whereupon the sheathing or the formwork panels can be applied to the grid elements. 
     Alternatively, however, it is also possible to form the formwork elements such that a sheathing is applied directly to the carrier explained above, in particular onto its upper sides. In this case, already completed formwork panels comprising sheathing and carriers are installed on the vertical supports in the manner in accordance with the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in the following with reference to embodiments and to the drawings; there are shown in these: 
         FIG. 1  is a three-dimensional view of an end section of a carrier being used within the framework of the invention and couplable to the head of a vertical support; 
         FIG. 2  is a three-dimensional view of a head of a vertical support couplable to a carrier in accordance with  FIG. 1  obliquely from above; 
         FIG. 3  is a three-dimensional view of a carrier in accordance with  FIG. 1  coupled to a head of a vertical support in accordance with  FIG. 2  in a first fastening position obliquely from above; 
         FIG. 4  is a view in accordance with  FIG. 3  obliquely from below with the realization of a second fastening position; 
         FIGS. 5   a - c  illustratre different method steps in side view, on the coupling of a carrier in accordance with  FIG. 1  with a head in accordance with  FIG. 2 ; 
         FIGS. 6   a - c  are views similar to  FIGS. 5   a - c , with a head of a vertical support rotated by 90°; 
         FIG. 7  is a three-dimensional view of a vertical support head coupled with four carriers obliquely from below, with two carriers being aligned perpendicular to two further carriers; and 
         FIG. 8  is a view in accordance with  FIG. 7  in which all four carriers extend parallel to one another. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The carrier  2  shown in  FIG. 1  is made as an open elongated section element which has a C-shaped section with two limbs extending away from a base section  4 , with the lower limb being designed as a support surface  6  for placing on a head of a vertical support. The upper limb supported at the base section  4  for reinforcement with a diagonal strut  7  forms a support surface  8  for the lower sides of longitudinal members which extend, for example, perpendicular to the carrier  2 , which forms a cross member in this case, so that the named longitudinal members, together with the carrier  2  and optionally with further cross members, form a grid element onto which a sheathing can be applied. Alternatively, the contact surface  8  can also serve directly as a contact surface for a sheathing. 
     In the carrier  2  shown, the base section  4 —viewed in cross-section—is longer than the contact surface  8 , which is in turn longer than the support surface  6 . The length of the contact surface  8  amounts to approximately twice the length of the support surface  6 , whereas the length of the base section  4  amounts to approximately twice the length of the contact surface  8 . 
     The lower side of the support surface  6  does not extend parallel to the contact surface  8 , but rather obliquely upwardly in the direction of the contact surface  8 . It results in this manner that the thickness of the support surface  6  becomes smaller as the spacing from the base section  4  increases, since the upper side of the support surface  6  facing the contact surface  8  extends, unlike its lower side, parallel to the contact surface  8 . The advantages of this design will be explained in the following in connection with  FIGS. 5   a - c.    
     An upwardly angled lug  10  is shaped on the end of the support surface  6  remote from the base section  4  and extends parallel to the base section  4  in the direction of the contact surface  8 . Alternatively to the named angling, a round transition could also be formed between the support surface  6  and the lug  10  so that e.g. substantially the shape of a quarter-circle is adopted in cross-section between the support surface  6  and the lug  10 . The lug  10  in the embodiment shown is provided with two V-shaped cut-outs  12 ,  14 ,  12 ,  14  which are spaced apart from one another in the longitudinal direction of the carrier  2 , with the width of these cut-outs  12  to  18  each reducing as the spacing from the contact surface increases. The cut-outs  12  to  14  extend over the total height of the lug  10  and merge in their lower end region into recesses  20 ,  22 , of the support surface  6 . The width of the recesses  20  to  22  in this process corresponds approximately to the width of the V-shaped cut-outs  12  to  14  in their end region facing the recesses  20  to  22 . The recesses  20  to  22  extend into the support surface  6  by less than half the length of the support surface  6 . 
     Due to their U-shaped design, the cut-outs  12  to  14  can form a “threading aid” for the introduction of fixing elements into the recesses  20  to  22  by the named arrangement of the cut-outs  12  to  14  and of the recesses  20  to  22 , with this threading aid in particular being effective when the carrier  2  is pivoted upwardly by 90° into its position shown in  FIG. 1  after the guiding up to a fixing element. This pivot movement is promoted by the explained oblique orientation of the lower side of the support surface  6 . 
     Only an end region of the carrier  2  is shown in  FIG. 1 . The other end region, not shown, of the carrier  2  is made analogously to the end region shown so that the carrier  2  has two respective cut-outs  12  to  14  and two recesses  20  to  22  in each of its two end regions. 
       FIG. 2  shows in a three-dimensional view a head  28  which can be coupled to a vertical support (not shown). In this connection, the head  28  is made from a steel plate which was originally substantially rectangular and which is bent such that a section  30  is formed in its middle region which is bent substantially into a U-shape, which extends upwardly over the whole width of the head  28  and which has one respective outwardly projecting abutment bead  31  at both sides in its upper section. The U-shaped section  30  in this process divides the base surface of the head  28  formed as a support plane  32  into two halves of equal size between them. With carriers  2  installed at the head  28 , the named support plane  32  absorbs the vertical forces to be transmitted from the carriers  2  onto a vertical support since the support surface  6  of a carrier  2  is ultimately supported on the support plane  32  of the head  28 , which will be explained in the following. 
     Spaced apart perpendicularly from the U-shaped section  30 , the support plane  32  has a respective coupling lug  34  which is curved downwardly in U shape at its two end regions remote from one another so that a receiving plane for a head plate (not shown) of a vertical support is defined between the coupling lugs  34  facing one another which extends parallel to the support plane  32 . A head plate of this type can be pushed in the longitudinal direction of the U-shaped section  30  into the coupling lugs  34  until it abuts two abutment members  36  which are made integrally with the U-shaped section and extend downwardly, starting from this, into the named receiving plane for the head plate of the vertical support. Only one of these abutment members  36  can be seen in  FIG. 1 . 
     A spring member is fastened in the hollow space surrounded by the U-shaped section  30 . The end sections  40  of the spring member  38  are curved in the region of an opening  42  of the U-shaped section  30  and in the region of an end-face end of the U-shaped section  30  such that the spring member  38  is captively held at the head  28 . The spring member  38  is shaped in this process such that a middle section of the same extends downwardly at least up to and into the receiving plane provided for the head plate of a vertical support and formed between the coupling lugs  34  such that the named section of the spring member  38  can snap into an end face hollow space of a vertical support or of a head plate of a vertical support, whereby the head  28  can be fixed in a defined position with respect to a vertical support. In such a position, the two abutment elements  36  abut an edge of the head plate of a vertical support. When the head  28  is pulled from a vertical support, the spring member is deformed by the removal force such that the spring member ensures a correct positioning of the head  28  relative to the vertical support, on the one hand, but also permits a subsequent release of the head  28  from a vertical support, on the other hand. 
     The four corner regions of the support plane  32  are each bent upwardly perpendicular to the support plane  32  so that they form a total of eight fixing lugs  44 - 51  which each extend either perpendicular or parallel to the longitudinal direction of the U-shaped section  30 . Two respective fixing lugs  51 ,  44 ;  45 ,  46 ;  47 ,  48 ;  49 ,  50  oriented perpendicular to one another and adjacent to one another are associated with one respective corner each of the support plane  32 . The width of the fixing lugs  44  to  51  amounts to somewhat more than twice their height, with the corner regions of the fixing lugs  44  to  51  remote from the support plane  32  in each case being chamfered. Each perpendicular edge  52 ,  54 ;  56 ,  58 ;  60 ,  62 ;  64 ,  66  of the fixing lugs  44  to  51  in this process forms a respective fixing element which is suitable in the sense of the invention for an engagement into a recess  20  to  26  of a carrier  2 . On a coupling of a carrier  2  via one of the fixing lugs  44  to  51 , in each case only one of the two fixing elements  52  to  66  of a fixing lug  44  to  51  always becomes effective. The provision of two fixing elements  52  to  66  per fixing lug pair  51 ,  44 ;  45 ,  46 ;  47 ,  48 ;  49 ,  50  makes it possible selectively to couple a carrier  2  to a fixing lug  44  to  51  in two directions offset to one another by 90° and extending parallel to the support plane  32 . 
     An abutment lug  68 ,  70  is bent upwardly out of each of the two halves of the support plane  32 , with each of the two end face edges extending perpendicular to the support plane  32  of the abutment lugs  68 ,  70  each forming an abutment surface  72 ,  74 ,  76 ,  78  for the rear side of the base section  4  of a carrier  2 . 
     Four further abutment surfaces  80 ,  82 ,  84 ,  86  are formed by regions of the U-shaped section  30 , in particular by its abutment beads  31 , extending perpendicular to the support plane  32 . These abutment surfaces  80  to  86  are also each suitable to cooperate with the rear side of the base section  4  of a carrier  2 . 
     Specifically, a carrier  2  can be fixed between the following pairs of mutually respectively oppositely disposed fixing elements  52  to  66  and abutment surfaces  72  to  86 : 
       52 ,  80 ;  54 ,  72 ;  56 ,  74 ;  58 ,  82 ;  60 ,  84 ;  62 ,  76 ;  64 ,  78 ;  66 ,  86 . 
     In accordance with the invention, all those fixing lugs  46 ,  47 ,  50 ,  51  which extend perpendicular to the longitudinal direction of the U-shaped section  30  each have a first hook element  87  at their fixing elements  58 ,  60 ,  66 ,  52  which extends in each case toward the U-shaped section  30  and, viewed from above, forms an undercut which can be engaged behind by a second hook element or by a support surface  6  of a carrier  2 . 
     The other fixing elements  54 ,  56 ,  62 ,  64  of the remaining fixing lugs are free of first hook elements  87 . It is achieved in this manner that a carrier  2  extending parallel to the longitudinal direction of the U-shaped section  30  and coupled to the head  28  is secured against a lifting off from the head  28  by first hook elements  87 , whereas a carrier  2  extending perpendicular to the longitudinal direction of the U-shaped section  30  and coupled to the head  28  can lift vertically upwardly from the head  28  due to the lack of first hook elements  87  at the fixing elements  54 ,  56 ,  62 ,  64 . 
       FIGS. 3 and 4  show a head plate  88  of a vertical support  90  which is pushed so far into coupling lugs  34  of a head  28  until an edge of the head plate  88  abuts the abutment elements  36  of the head  28 . A respective carrier  2  in accordance with  FIG. 1  is coupled to the head  28  and longitudinal members  92  are fastened to its contact surface  8  and extend perpendicular to the carrier  2 . In accordance with  FIG. 4 , a sheathing  94  is secured to the upper side of the longitudinal members  92  and is in turn coupled to a bulk formwork  96 . 
     In accordance with  FIGS. 3 and 4 , the carrier  2  is coupled to the head  28  such that the fixing element  52  extends into the cut-out  12  and into the recess  20  ( FIG. 1 ). At the same time, the fixing element  58  extends into the cut-out  14  and the recess  22  ( FIG. 1 ). The base section  4  of the carrier  2  in this process is supported at its rear side at the abutment surfaces  80  and  82  so that ultimately these abutment surfaces  80 ,  82 , together with the fixing elements  52 ,  58 , effectively prevent the carrier  2  from being able to move perpendicular to its base section  4 . The engagement between the fixing elements  52 ,  58  and the recesses  20 ,  22  simultaneously ensures that no movement can take place relative to the head  28  in the longitudinal direction of the carrier  2 . 
     Alternatively, the carrier  2  could also be coupled to the head  28  in a position which is offset in the longitudinal direction of the carrier  2  and in which the fixing element  58  would engage into the cut-out  12  or into the recess  20  corresponding therewith. 
     In this case, the carrier  2  would then no longer extend beyond the whole support plane  32  of the head  28  as in accordance with  FIGS. 3 and 4 . It would rather only extend over less than half the width of the support plane  32  so that, for example, a further carrier  2  could be coupled to the head  28  via the fixing element  52  so that both carriers  2  would extend aligned with one another in the longitudinal direction. 
     Finally, a carrier  2  could also be coupled to the head  28  via its cut-outs  12 ,  14  or recesses  20 ,  22  such that it extends perpendicular to its alignment shown in  FIG. 3 . In this case, the fixing element  54  would then engage into one of the recesses  20 ,  22 , with the rear side of the base section  4  of the carrier being supported at the abutment surface  72  of the abutment lug  68 . 
     It is in particular also possible to couple two, three or four carriers  2  to the head  28 , with each of the carriers  2  then being able to be fixed between one of the pairs of fixing elements  52  to  66  and abutment surfaces  72  to  86  already named above. The individual carriers  2  can extend parallel or also perpendicular to one another. 
       FIGS. 5   a - c  show how a coupling can be established between the carrier  2  and the head  28  as is shown in  FIG. 3 . 
     First, a formwork element  98  comprising carriers  2  and longitudinal members  92  is aligned relative to a vertical support  90  such that the longitudinal members  92  extend either substantially parallel to the vertical support  90  or—as shown in  FIG. 5   a —somewhat obliquely to this alignment. In this alignment, a formwork element  98  can be taken up easily and raised by a fitter such that the carrier  2  is ultimately located above a head  28  of the vertical support  90 . Starting from this raised position, the formwork element  98  is then aligned and lowered by the fitter such that the fixing elements  52 ,  58  are introduced into the V-shaped cut-outs  12 ,  14  of the lug  10 . This introduction is facilitated by the V shape of the cut-outs  12 ,  14 . The first hook elements  87  of the fixing elements  52 ,  58  only project so far in the direction of the U-shaped section  30  that the named introduction is not impeded. In this manner, a hook connection is therefore already established between the head  28  and the carrier  2  in which the weight of the formwork element  98  can be led to a greater part via the support plane  32  into the vertical support  90  such that the person carrying out the assembly no longer has to hold the full weight of the formwork element  98 . 
     Starting from the hook connection in accordance with  FIG. 5   a , the formwork element  98  in accordance with  FIG. 5   b  is now pivoted upwardly in the arrow direction around a pivot axis extending parallel to the longitudinal axis of the cross member  2 , with the fixing elements  52 ,  58 —guided by the V-shaped cut-outs  12 ,  14 —automatically being moved into the recesses  20 ,  22  of the support surface  6  of the carrier  2  during this pivot movement. The named pivot movement is continued for so long until the position in accordance with  FIG. 5   c  is reached in which the formwork element  98  and its longitudinal member  92  extend perpendicular to the vertical support  90  in the horizontal direction. It can be seen particularly illustratively from  FIG. 5   c  that the abutment surfaces  80 ,  82  in this completely mounted position effectively prevent the carrier  2  from moving in the arrow direction perpendicular to the base section  4  of the carrier  2  such that the fixing elements  52 ,  58  move out of engagement with the recesses  20 ,  22 .  FIG. 5   c  furthermore shows that the first hook elements  87  were moved solely by the named pivot movement into a position in which they engage over the recess-free region of the support surface or of the second hook elements  6  such that the formwork element  98  cannot be raised perpendicularly upwardly parallel to the base section  4 . A release from the head  28  and from the formwork element  98  is consequently only possible when the formwork element  98  is pivoted downwardly against the direction of the arrow of  FIG. 5   b.    
     If, within the framework of the dismantling of the formwork element  98 , work is carried out in the reverse order, as described in connection with  FIGS. 5   a - c , the slope formed at the lower side of the support surface  5  which includes an angle of approximately 75° with the base section  4  comes advantageously into effect. It namely becomes possible on the basis of this slope to pivot the formwork element  98  away, starting from the position in accordance with  FIG. 5   c , against the arrow direction of  FIG. 5   b , without a clamping effect occurring between the upper side of the formwork element  98 , a sheathing lying thereon and an already prepared concrete slab. The slope rather ensures that all parts of the formwork element  98  move downwardly on the pivoting away such that a problem-free stripping becomes possible. 
       FIGS. 6   a - c  illustrate that a corresponding coupling process can be realized when it is ultimately desired for the fully installed formwork element  98  to extend at an angle relative to the head  28  offset by 90° with respect to  FIGS. 3 and 5   a - c  without realizing a lift-off safeguard. In this case, the fixing element  64  then, for example, cooperates with the cut-out  12  or with the recess  20  of the carrier  2 . The pivot process described runs in accordance with  FIGS. 6   a  to  6   c  analog to the pivot process described in connection with  FIGS. 5   a - c  with the difference that the rear side of the base section  4  of the carrier  2  in accordance with  FIG. 6   c  is ultimately supported at the support surface  78  of the abutment lug  70 , whereby it is in turn avoided that the fixing element  64  can move out of the recess  20  or  22 . It can furthermore be seen from  FIG. 6   c  that the fixing element  64  does not have any first hook element  87  so that the formwork element  98  can be raised perpendicularly upwardly parallel to the base section  4 . 
       FIG. 7  shows a total of four carriers  100 ,  102 ,  104 ,  106  which are coupled to a head  28  of a vertical support  90 . The two carriers  100 ,  102  are arranged aligned with one another spaced apart from one another at the end face, whereas the two carriers  104 ,  106  extend parallel to one another and perpendicular to the carriers  100 ,  102 . All carriers  100  to  106  are made in the manner described in connection with the carrier  2  in accordance with  FIG. 1 . The following fixing elements, recesses and abutment surfaces cooperate here with respect to the different carriers  100  to  106 : 
     carrier  100 : fixing element  56 , recess  20 , abutment surface  74   
     carrier  102 : fixing element  62 , recess  20 , abutment surface  76   
     carrier  104 : fixing element  52 , recess  20 , abutment surface  80   
     carrier  106 : fixing element  66 , recess  20 , abutment surface  86   
     The carriers  104 ,  106  are—contrary to the carriers  100 ,  102 —secured against a lifting off due to the cooperation with the fixing elements  52 ,  66  which each have a first hook element  87 . 
       FIG. 8  shows an arrangement in which all the carriers  100  to  106  extend parallel to one another, with in each case two carriers  100  and  106  or  102  and  104  respectively being arranged aligned with one another in the longitudinal direction spaced apart from one another at the end face. In this arrangement, the following fixing elements, recesses and abutment surfaces cooperate: 
     carrier  100 : fixing element  52 , recess  20 , abutment surface  80   
     carrier  102 : fixing element  66 , recess  20 , abutment surface  86   
     carrier  104 : fixing element  60 , recess  20 , abutment surface  84   
     carrier  106 : fixing element  58 , recess  20 , abutment surface  82   
     All the carriers  104 ,  106 ,  100 ,  102  are secured against a lifting off due to the cooperation with the fixing elements  52 ,  58 ,  60 ,  66  which each have a first hook element  87 . 
     In accordance with the invention, any other desired arrangements of one to four carriers at one head  28  can also be realized. In each carrier  2  coupled with a head  28  via one of the two outer recesses  20  or  22 , two different alignments of the carrier  2  offset to one another by 90° can be realized completely independently of all other carriers  2  coupled to the head  28 .