Patent Publication Number: US-2013227822-A1

Title: Load-bearing apparatus for introducing load forces, such as cable forces or tensioning forces, for example, from surface structures

Description:
The invention relates to a load-bearing apparatus for introducing load forces, such as cable forces or tensioning forces, for example, from surface structures, into supporting structures and that comprises a tension element, which is connected to an anchoring element of the supporting structure, and with which a connecting device for tension members interacts, said connecting device being pivotable about a first pivot axis and having at least one connecting wing that projects laterally with respect to the tension element and forms at least one connecting point, which is offset with respect to the tension element, for a tension member in question. 
     Modern architecture has increasingly incorporated concepts of load-bearing structures, where planar elements, such as tent-like or umbrella-like coverings that form, as a textile or membrane-like building material, part of a load-bearing structure, are anchored or erected on supporting structures, for example, steel supports. In order to achieve that the respective elements form space-creating structures of a desired architectural design, the respective suitable introduction of load forces, in particular, the tensioning or bearing cable forces, is a crucial factor. In order to avoid distortions of the desired architectural design, it is customary to anchor the sheet-like elements on a plurality of attachment points. A load-bearing apparatus that is useful for this purpose and that conforms to the genre described above is disclosed in document WO 2010/054702 A1. The load-bearing apparatus known from the prior art allows the load forces of a plurality of tension members to be introduced over a connecting device into a pertinent tie bar, which in turn is connected to a pole-like support or a part of a building by means of an anchoring element. 
     Depending on the structural configuration of the load-bearing structures, the tension members acting on the connecting part experience different tensioning directions as a function of the various lines of action of the effective load forces. Hence, there is the risk that in the event of corresponding force flows, the induced transverse forces act on the connecting part and put an excessive material load on the tension element, for example, in the form of a tie bar. The resulting failure of a load-bearing apparatus can lead to the collapse of the entire load-bearing structure and, therefore, presents a correspondingly high safety risk. 
     In light of this problem, the object of the present invention is to provide a load-bearing apparatus of the type under consideration that makes it possible to ensure an especially reliable introduction of the load forces, acting with different tensioning directions, into the support structures. 
     The invention achieves this object with a load-bearing apparatus having the features specified in claim  1  in its entirety. 
     According to the characterizing part of claim  1 , an essential feature of the invention consists of the fact that the at least one connecting wing is in abutment with the tension element by way of an articulation arrangement such that it is pivotable about at least one additional pivot axis in relation to the tension element. As a result, the connecting wing has a multi-axis setting possibility in relation to the tension element, so that under load due to the tension members the connecting wing can move into a stabilized position, so that the multi-axis pivoting mobility does not generate any transverse forces at the tension element. 
     In preferred exemplary embodiments, the linear tension element is formed by a tensioning cable or, in particular, a tie bar. 
     In this case, the connecting device and with it the respective connecting wing is pivotable preferably about the axis of the tension element concerned. 
     This pivoting possibility is implemented in an especially advantageous manner in that a spherical body is attached to the tension element, in particular, the tie bar. In order to form an articulation node at the anchoring element of the supporting structure, this spherical body is mounted on a support surface that forms a part of the spherical cap. In addition to the rotating mobility of the connecting part about the axis of the tension element, the result is an additional ball joint that allows the tension element itself to perform pivoting motions about any axis in relation to the anchoring element. 
     With respect to the articulation arrangement between the tension element and the connecting device, the arrangement is configured preferably in such a way that the connecting device is pivotable about an axis that is vertical to the axis of the tension element. 
     In this case, the arrangement can be configured in an especially advantageous way so that the connecting device is mounted on the tension element in such a way that it is pivotable about the longitudinal axis of said tension element. 
     For an especially advantageous connection of a plurality of tension members with a connecting device, this connecting device can have two connecting wings, which extend away from the tension element in different directions. 
     In order to make the multi-axis setting possibility available to the connecting device, the arrangement can be configured to great advantage such that the connecting device is connected to the tension element by means of an articulation arrangement that enables the pivoting mobility about the longitudinal axis of the tension element and about the at least one additional pivot axis. 
     In such exemplary embodiments, the arrangement can be configured advantageously in such a way that the connecting part for the tension element forms a passage, which expands from the front end, which is assigned to the free end of the tension element, to the rear end in the direction of the lateral connecting wing, and that the front end of the passage has rotation surfaces that interact as part of the articulation arrangement with the rotation surfaces on a retaining body, which can be secured on the tension element. What is meant with the concept of interacting rotation surfaces is that those surfaces represent, like circular ring surfaces or spherical surface parts in the event of their mutual abutment, sliding bearing surfaces for the relative rotation motions (pivoting motions). 
     In this case, the arrangement can be configured to great advantage in such a way that the connecting part has two plates, which are held at a distance from each other by means of connecting wings fastened on both sides between said plates, in order to form the passage. At the front end of the passage, the two plates have circular ring surfaces, which form with an adjacent circular ring surface of the retaining body the sliding mounting for a pivoting motion with the pivot axis vertical to the longitudinal axis. 
     The circular arc surfaces on the connecting part can be, for example, concavely curved and on the retaining body convexly curved or vice versa. 
     In especially advantageous exemplary embodiments, the connecting part has a body, in which there is a passage that widens from its front end in the direction of the connecting wings and with which the lateral connecting wings are constructed in one piece, with the retaining body having a spherical surface section that forms a ball joint on the connecting part with a seat that forms a part of a spherical surface. An articulation arrangement in the manner of a ball joint enables a pivoting motion about any axis and, therefore, a free setting possibility for the connecting device in relation to the tension element. 
     In an alternative exemplary embodiment, two connecting wings with a common pivot axis are mounted in a pivotable manner independently of one another on the connecting device. As a result, the connecting points can be used, independently of each other, as additional setting possibilities, for the tension members in relation to the connecting device and in relation to each other, as a function of the load. 
     With respect to securing the retaining body on the tension element, the arrangement can be configured in such a way that the tension element forms an external thread on which a tightening nut forms an axial lock of the retaining body. 
    
    
     
       The invention is explained in detail below by means of exemplary embodiments that are shown in the drawings. These drawings show in 
         FIGS. 1 and 2  a top view and a perspective oblique view respectively of an exemplary embodiment of the load-bearing apparatus according to the invention; 
         FIG. 3  a perspective oblique view of a second exemplary embodiment of the load-bearing apparatus; 
         FIG. 4  a perspective oblique view of an exemplary embodiment from  FIG. 3 , but in this case the position of the connecting device with respect to the tie bar has changed from that shown in  FIG. 3 ; 
         FIG. 5  a perspective oblique view that is similar to the one shown in  FIG. 3 , but in this case a modified anchoring element is shown; 
         FIG. 6  a perspective oblique view of an additional exemplary embodiment of the load-bearing apparatus; 
         FIG. 7  a detail that is drawn to a larger scale than in  FIG. 6  and corresponds to the sectional line VII-VII from  FIG. 6 ; 
         FIG. 8  a perspective oblique view that is similar to the one shown in  FIG. 6 , but in this case the position of the connecting device relative to the tie bar is changed; 
         FIGS. 9 and 10  a perspective oblique view of an additional exemplary embodiment, and 
         FIGS. 11 and 12  a perspective oblique view of an exemplary embodiment with connecting wings that can be pivoted relative to one another. 
     
    
    
       FIGS. 1 and 2  show a first exemplary embodiment of the load-bearing apparatus with a tie bar  2  serving as the tension element. This tie bar is connected to an anchoring element  4  that is screwed together with a supporting structure (not illustrated), for example, with the pole head of a steel support or with a building wall. The tie bar  2  has an external thread on a longitudinal region adjacent to the free end of the tie bar. On this external thread, which is not shown per se in the drawing, a tightening nut  6  secures a retaining body  8  against an axial movement toward the free end of the tie bar  2 . On the other anchoring end of the tie bar  2 , a spherical body  10  is attached to said tie bar. This spherical body is mounted on a support surface  12  on the anchoring element  4 ; and this support surface forms a part of a spherical cap, so that together with the spherical body  10  an articulation node is formed in the manner of a ball joint on the anchoring element  4 . 
     A connecting device, which is designated as a whole as  14 , is provided for introducing the load forces by way of the tie bar  2  into the anchoring element  4 . This connecting device together with the tie bar  2  is arranged on the articulation node of the anchoring element  4  in such a way that it can be rotated about the longitudinal axis of the connecting device. The connecting device  14  has two identical plates  16  that are shaped, for example, in the manner of an obtuse triangle, with the blunt corner of the triangular form facing the free end of the tie bar  2 . The connecting device  14  is completed with connecting wings  18 , which project away from the mutually converging side edges  20  of the plates  16 , and with connecting eyelets  22  for the tension members, for example, in the form of tensioning cables. The connecting wings  18  are inserted between the plates  16  and form spacers, so that an inner passage for the tie bar  2  is formed between the plates  16 . This passage, which can be seen through the breakthroughs  24  in the plates  16 , is defined laterally by the diverging inner edges  26  of the wings  18 , so that the passage widens, as shown in the drawing, from the end, facing the retaining body  8 , to the rear. As a result, the connecting device  14  can perform on the tie bar  2  a pivoting motion with the pivot axis, which is vertical to the axis of the tie bar, about the pivot center at the retaining body  8 , and in particular, in addition to the rotating or pivoting motion about the axis of the tie bar  2 . In order to form the corresponding pivoting center on the retaining body  8 , the retaining body  8  has a convex shape in the form of a sliding surface  28 , which corresponds to a circular ring section, on its surface opposite the flat engagement surface on the tightening nut  6  This sliding surface together with the concave circular ring surfaces  30  on the plates  16  forms the pivot mounting, whose axial position on the tie bar  2  can be fixed by means of the tightening nut  6 . 
     The second exemplary embodiment, according to  FIGS. 3 and 4 , differs from the above-described example only in so far as, instead of the convex sliding surface  28  provided on the retaining body  8 , a concave sliding surface  32  is now formed which interacts with the convex circular ring surfaces  34  on the plates  16 .  FIG. 4  shows the connecting device  14  in a position in which it is deflected, as compared to  FIG. 3 , i.e., in a position swivelled about the pivoting center on the retaining body  8 . 
     The example from  FIG. 5  corresponds to the previous example from  FIGS. 3 and 4 , apart from the fact that the anchoring element  4  is constructed in the form of a cup, with the inner wall of the cup forming the support surface  12  in the shape of a spherical cap; and the opening provided on the cup bottom for the tie bar  2  is dimensioned in such a way that free space for the ball joint function is made available for movements of the tie bar  2 . 
     The additional exemplary embodiment, shown in  FIGS. 6 to 8 , provides a one-piece connecting device  14 , inside of which there is a passage that widens laterally. It can be seen best from  FIG. 7  that a spherical surface part  36  is formed on the end of the passage facing the retaining body  8  as the seat for the retaining body  8 . This spherical surface part forms a ball joint in interaction with a spherical surface section  38  on the retaining body  8 . Therefore, in this exemplary embodiment, the connecting device  14  has not only the ability to rotate about the axis of the tie bar  2  and to pivot vertically to this axis, but also the connecting device  14  is freely movable on the tie bar  2 , save for the securing against axial motion. 
       FIGS. 9 and 10  show an additional exemplary embodiment in which the retaining body  8 , which is axially secured on the tension element  2 , has a cylindrical body  52 , which extends through the passage formed between the plates  16 . The cylindrical body  52  forms with its cylindrical jacket the sliding surfaces  28 , which form with the circular ring surfaces  30  of the plates  16  extending through from the cylindrical body  52 , the swivel mounting for the connecting device  14  with the pivot axis vertical to the axis of the tension element  2 . Preferably, however, it is provided that the bolt-like cylindrical body  52  is fixed with the retaining body  8  on the tie bar  2 ; and the connecting wings  18  are guided around the cylindrical body  52  in such a way that they can rotate about the additional pivot axis. 
     The additional exemplary embodiment, shown in  FIGS. 11 and 12 , differs from the above-described exemplary embodiment in a specific way in that the connecting wings  18  are mounted in a pivotable manner independently of each other on the connecting device  14 , so that the result is the mounting at  46  about a common pivot axis. In order to form the mounting, the connecting wings  18  have in each case a two-armed fork-type joint  44  on the connecting end.