FACADE FASTENING SYSTEM, RETAINING ELEMENT FOR IT AND ASSEMBLY PROCEDURE

Description

[0001] The present invention relates to a system for facade fastening, more precisely: an invisibly fastened, suspended, ventilated facade fastening system which is simplified compared to the prior art and allows for more flexible installation. Furthermore, a mounting system is described that allows for quick and easy fastening of facade panels, as well as its use and / or method for installation. BACKGROUND

[0002] In modern residential and commercial construction, a building envelope must fulfill a multitude of functions: acting as a barrier against the elements, providing thermal and acoustic insulation, and, not least, serving as a design element that gives a building its distinctive character. A ventilated facade is a building envelope that, unlike plaster or paint, is not applied directly to a load-bearing exterior wall, but rather attached to it at a distance. Insulation layers are often installed between this exterior wall and the facade panels. DEFINITIONS

[0003] A substructure is attached to a load-bearing or structural wall that encloses the building. This substructure defines a mounting plane at a certain distance from the building wall. Facade panels are attached to this mounting plane using fastening elements. The assembly of the substructure, fastening elements, and facade panels is referred to as the facade. The building envelope typically refers to the facade together with the windows, doors, insulation layers, and roof.

[0004] In the following, the term "facade panel" refers to the building components that form the large, externally visible part of the facade. These facade panels are typically large, flat, and often have a square or rectangular shape. They can be made of metal, fiber cement, plastics, natural stone, ceramic, wood, or composite materials (e.g., a sandwich construction of metal sheets with a honeycomb core). They serve to protect, insulate, clad, and / or decorate the building.

[0005] "Retaining elements" are mechanical components that create a load-bearing connection between a facade panel and a mounting surface of the substructure. They form the mechanical interface between the substructure and the facade panel. Retaining elements can be designed so that they are invisible after the building envelope is installed, meaning they are concealed by the facade once the building envelope is complete.

[0006] The term "substructure" refers to a load-bearing structure that defines the distance between a load-bearing building wall and the mounting surface. The mounting surface and building wall can be flat, even, and parallel, but this is not mandatory. A substructure can also provide an uneven, curved, corrugated, or ribbed mounting surface. It is very common to use horizontal and / or vertical profile rail systems that are connected to the load-bearing outer building wall via spacers (beams). These profile systems provide the mounting areas (stop surfaces, recesses, pre-drilled holes) for the fixing elements. Suitable construction materials include, for example, steel, aluminum, and / or wood.

[0007] For the purposes of this invention, a facade fastening system refers to fastening elements that, on the one hand, have fastening points / surfaces to a facade panel and, on the other hand, provide sliding points and / or fixed points between the facade elements and the receiving surfaces of the substructure. The fastening methods are diverse (hanging, screwing, gluing, riveting, snapping).

[0008] In this application, a trapezoid, trapezoidal shape, or trapezoidal refers to a quadrilateral with two parallel sides of different lengths (the longer base and the shorter base). Specifically, it refers to an isosceles or symmetrical trapezoid, where the adjacent interior angles of each base are equal. The sides connecting the bases are called legs and are consequently also of equal length. This geometry is shown and described in the figures in a mathematical sense; logically, for those skilled in the art, the trapezoidal shape in its technical implementation may, of course, have rounded rather than exact vertices. Likewise, in its technical implementation, the trapezoid may also have slightly curved bases or legs for technical reasons, without thereby abandoning or obscuring the basic idea or shape of the trapezoid. STATE OF THE ART

[0009] A wide variety of facade designs and fastening systems are known in the art. The weight, size, and material of the facade panel significantly influence the fastening method, both for the facade panel(s) to the substructure and for the substructure to the load-bearing building structure. The substructure must transfer the load from the suspended elements into the building wall. Furthermore, wind loads, thermal influences, and architectural requirements must be taken into account. This necessitates considerable effort in the planning and installation of both the substructure and the facade panels.

[0010] Large facade panels are often used for aesthetic reasons, and these naturally need to be adapted to windows, doors, building corners, and roof edges. Installation, especially at the bottom edge of windows and roofs, should be straightforward. Individual facade panels should also be easy to remove, whether for replacement in case of damage or to access the underlying insulation or building structure.

[0011] Large facade panels like these can be quite heavy and therefore require numerous fixings to connect them to the substructure. If these facade panels are to be installed as hung facades, concealing the mechanical connection points to the substructure, the installation effort increases further. The most obvious fixing method—fastening a facade panel along its edge(s) and overlapping the fixing points with the next panel—makes it difficult to replace individual defective facade panels.

[0012] Due to the different thermal expansion rates of the facade panels compared to the substructure, their connection points must be designed as sliding and fixed points to avoid unnecessary mechanical stresses. A solution to this problem must not require any compromises in terms of installation effort or safety.

[0013] German patent application DE 197 07 564 A1 describes a mounting system for a suspended ceiling made of cladding elements. It comprises a support profile rail and snap-in clips to be attached to the cladding elements. Installation is accomplished by attaching the support profile rail to the ceiling and then fixing a cladding element to the ceiling by sliding the snap-in clip onto the support profile rail. German patent application DE 20 2013 100026 U1 discloses all features of the preamble to claim 1.

[0014] The invention therefore aims to describe a facade system that requires as few components as possible, is easy to assemble and adjust, and can be invisibly fastened. This is achieved by the features of independent claim 1. Furthermore, the invention relates to a method for assembling a facade system. DESCRIPTION OF THE INVENTION

[0015] A retaining element according to the present invention forms a type of interface between a facade panel on the one hand and a substructure on the other. More precisely, the retaining element is designed and intended for placement between the back of a facade panel on the one hand and a facade support on the other. As expected, the retaining element will therefore need to have at least two fastening sections that are rigidly connected to each other. By fastening section, we mean (abstractly functionally) a region, a section, a surface, an area of ​​the retaining element that is suitable and designed to provide this fastening, i.e., to dissipate its own weight as well as any tensions and loads from external influences without being damaged. The fastening is achieved using additional means such as screws, rivets, adhesives, clamps, or a suitable combination thereof.

[0016] Specifically, in the case of the retaining element presented here, a spring-loaded connection or a clamp is to be used for the second fastening section.

[0017] In a more specialized version, the second fastening section uses exclusively a spring-loaded connection or clamp. Functionally speaking, this means that the second fastening section is designed or intended to only use a spring-loaded fastening.

[0018] At first glance, proposing a spring-loaded clamp as a fastener seems inappropriate in light of the safety and load criteria for facades listed above. However, a clamp differs from a screw connection primarily in the forces required to release the connection. Spring-loaded connections can be designed to be easier to install than to remove, and vice versa. In other words, the disadvantage of a smaller safety margin in a permanent connection can serve as an advantage during installation.

[0019] The clamp underlying the invention is designed as a pair of spring elements arranged symmetrically to the clamp's central axis, forming a receiving space open on one side between them. This receiving space is dimensioned such that it can receive a head profile at least frictionally or (alternatively) positively and frictionally. In other words, the receiving space will be shaped similarly to the outer contour of the head profile or designed in such a way that it encompasses this contour to such an extent that temporary securing can be achieved. A more detailed explanation will follow in connection with the Figures 4 , 8 and 9 .

[0020] Thus, the receiving chamber will have a trapezoidal cross-sectional shape with a long and a short base side, the short base side being parallel to and adjacent to the first fastening section, and the opening of the receiving chamber being located near the long base side. Furthermore, the spring elements of the clamp can then essentially be designed as two spring-loaded tongues and aligned along the legs of the receiving chamber.

[0021] The basic geometry of a trapezoid dictates that the spring-loaded tongues of the clamp can be slid onto the head profile from the narrow base of the trapezoid, with the trapezoidal legs of the head profile thus acting as ramps for the spring tongues. This means that the force increases continuously as the clamp is slid onto the head profile.

[0022] Preferably, the spring elements will further include detent devices or retaining means such as cams, embossings, tongues that can engage in correspondingly designed surface features of the head profile.

[0023] In other words, the spring elements can be designed so that, for example, the ends of the spring tongues are shaped in such a way that, in its end position, the clamp engages behind a trapezoidal head profile with these ends, thereby providing both a spring-like and locking action. If this connection is subjected to tensile stress, a considerable force must be applied before the clamp releases the head profile.

[0024] For reasons of symmetry and increased safety, a retaining element can also be designed or dimensioned to have two clamps. Preferably, this second, doubly equipped fastening section is manufactured so that the clamps are arranged symmetrically to the first fastening section.

[0025] As described above, the second fastening section will have one or two clamps for a resilient connection. This connection can be provided between the retaining element and a substructure, i.e., the facade support, which preferably, but not necessarily, can be arranged vertically. Alternatively, the second fastening section can also establish the connection between the retaining element and a reinforcing profile attached to the facade panel. Consequently, the reinforcing profile will have the trapezoidal head profile that is functionally suitable for the design of the clamps. This fundamentally functional usability "in two directions" does not automatically mean that a retaining element according to the invention must also be structurally identical. It can be universally applicable, but within the scope of the disclosure, it can also be designed differently to be better suited to both fundamental applications.

[0026] The use of a reinforcing profile on the back of a facade panel is advantageous, for example, with very thin, flexible, or rigidly brittle facade panels. Thin, large-format ceramic panels, for instance, exhibit excellent durability and colorfastness but are sensitive during transport and installation. Fastening methods that require drilling or transfer forces into the material, such as dowels or rivets, are generally unsuitable due to the risk of damage. In these cases, reinforcing profiles can be glued across the entire back surface. The structural elements extending from the back can then consist of trapezoidal profiles (head profiles) that are either longitudinally extended or available only in short sections and are mechanically compatible with the clips of the inventive fastening element.

[0027] In an advantageous further development, a third fastening section can be provided as part of the retaining element, enabling a non-resilient connection between the retaining element and the facade support and rigidly connected to the first fastening section. "Rigid" in this context means welded, molded, manufactured in one piece, bonded, or screwed. The rigid connection between the first and third fastening sections ensures that the force flow from the facade panel—that is, from the first to the second and simultaneously from the first to the third fastening section—is direct.

[0028] At the first fastening section (between the facade panel and the retaining element), stop / contact surfaces, bores, and / or elongated holes are preferably provided to achieve a force-fit and / or form-fit connection between the retaining element and a facade panel using fasteners such as screws, rivets, or adhesives. Depending on the weight and material of the facade panel, a specialist will select a fastening method that is intended or prescribed for that specific facade panel.

[0029] The aforementioned third fastening section can be designed as a tongue-shaped tab, which in turn features stop / contact surfaces, bores, and / or elongated holes. These allow for a force-fit and / or form-fit connection between the retaining element and the head profile of a facade support at its mounting surface, using fasteners such as screws, rivets, or adhesives. The third fastening section can thus serve as a safety device, supplementing the existing fixation via the clamp(s) of the second fastening section. Preferably, a retaining element with a third fastening section is mounted on the back of a facade panel in such a way that the tongue-shaped tab protrudes beyond its edge. During installation, the clamp of the second fastening section is engaged first on the retaining element, providing initial fixation until the tongue-shaped tab can be screwed to the head profile (at its mounting surface), for example.This is advantageous for assembly because no additional temporary securing devices such as clamps, straps, adhesive tapes, or tensioning systems are required. Adjusting to the final position is also simplified using the clamps of the second mounting section.

[0030] Instead of being part of or supplementing a holding element, the third fastening section can also be designed as a separate, independent positioning element. It can then also be manufactured as a tongue-shaped tab, which is attached on one side to the back of a facade panel (glued, riveted, screwed, etc.) and on the other side to a facade support of a substructure. The specialist will select the size and mounting location so that the load requirements are met and the function of a final fix is ​​fulfilled. By structurally separating the third fastening section and relocating it to its own component, greater flexibility in handling and installation is achieved.

[0031] A retaining element as described above is preferably manufactured as a bent or formed metal part, in particular from spring steel or a tough, elastic plastic. It is also conceivable to manufacture only the clamp from spring steel and permanently connect it to a remaining body designed as a sheet metal bent part. Likewise, a complete or partial extrusion from aluminum is possible. Depending on the material, bores and slots can be produced by punching, drilling, or milling, as is known in the art, and can also be threaded if required. Depending on the application, post-treatment of the retainers may be necessary, such as passivation, painting, or coating.

[0032] A substructure, particularly with the profile supports described here, but also with the described reinforcing profiles, can also be manufactured from metal as sheet metal bending parts or, in particular, as extruded aluminum profiles. These can be easily cut to the required length. Substructures are available on the market in a wide variety of versions. The present invention often relates to the part described as the head profile and shown in the drawings, because this is where the interaction with the retaining elements takes place.

[0033] A facade, in conjunction with the retaining element described here, can be defined as an assembly consisting of at least one facade panel, a substructure, and a plurality of retaining elements. Depending on the intended orientation of the retaining element clips (towards the reinforcement profile or towards the facade support), the facade panel will either have the majority of the attached retaining elements, or the substructure will have a plurality of vertically arranged facade supports. In this variant, the facade supports will have a head profile with a trapezoidal cross-sectional area and a mounting plane.

[0034] In the alternative orientation of the retaining elements, a plurality of reinforcement profiles aligned parallel to each other would be attached to the facade panel, while the substructure comprises a plurality of facade supports (not necessarily arranged vertically) with a plurality of retaining elements attached to them. According to the invention, the reinforcement profiles on the facade panels will then have a head profile with a trapezoidal cross-sectional area.

[0035] In the context of this invention, the head profile has a trapezoidal cross-sectional area in both cases, with the short base of this trapezoid lying in the mounting plane and having a width B 710. If the length of the short base of the receiving space of a retaining element is now designated B 200, this length B 200 can be selected such that it essentially corresponds to the width B 710 of the head profile. In other words, when the clamp and head profile are assembled, a positive fit is achieved between the clamp and the head profile.

[0036] Alternatively, the short base of the mounting space (length B 200) can be chosen to be larger than the width B 710 of the head profile. This results in lateral play in the mounting plane when the clamp and head profile are assembled. "Lateral" here refers to the longitudinal extent of the facade support, i.e., at right angles to its length; or, when viewed in the installed state, horizontally.

[0037] Why these two additional variants of B 200 retaining elements of different lengths? As mentioned in the first section of this description, different thermal expansion rates can occur between the facade panel and the substructure. The facade panel exposed to the environment will expand or contract more under sunlight or cool winds than the shaded substructure. This is addressed by using a combination of fixed and sliding points when fastening the facade panel(s). The number, type, and distribution of these points are determined by the size and weight of the panel(s) as well as by the substructure.

[0038] In addition to thermally induced movements, inaccuracies in the substructure's assembly must also be accommodated. Facade panels are typically prefabricated according to the architect's specifications and fitted with the fastening elements, possibly using automated machinery. This approach is particularly recommended when attaching the fastening elements, for example with ceramic panels, requires temperature control, careful handling, or is time-consuming. It is also advisable when special fasteners such as blind rivets are used, which require specific setting tools. Furthermore, handling adhesives or combinations of chemical and mechanical fasteners is easier under controlled conditions in a production hall than on a construction site.

[0039] A combination of form-fitting clamps and those with lateral play on a facade panel or the substructure makes it possible to compensate for tolerances of the substructure while still ensuring a primary holding function.

[0040] The following describes a method for attaching a facade panel to a substructure of facade beams, using the fastening elements discussed above. The subsequent steps follow a logical sequence in a minimal configuration without enforcing a strict timeline. Individual steps can be supplemented with inspection and adjustment steps, and pauses or delays do not alter the fundamental process described here. Individual setup steps can also be rearranged or performed iteratively, provided they remain technically equivalent.

[0041] The starting point for the assembly process is the provision of facade panels with mounting elements attached according to a predefined installation plan. Furthermore, a substructure with facade supports, attached to a building wall, is planned, manufactured, or provided, also according to the predefined installation plan. These installation plans are often based on structural calculations and load simulations and also serve for cost estimation.

[0042] Facade panels are generally attached to the facade supports by sliding the clips of the retaining elements onto the head profiles of the facade supports, where they spring around the head profile. As mentioned above, the two different types of retaining elements—those with positive-locking clips and those with lateral play—play a role in this process. The facade panel is then aligned to its intended final position according to the installation plan. Depending on the facade panel and the installation method, wedges, shims of a defined height or thickness, or adjustment elements are used for alignment. Since the clips of the retaining elements already possess a holding force in the vertical direction, the adjustment aids typically do not need to bear the full load of the panel. After successful alignment, individual retaining clips are secured by a force-fit connection of the third fastening section (or...).a positioning element) on the mounting surface of the head profile. Here too, fixed points and sliding points are possible depending on the design of the fastening method, e.g., as is well known in the prior art, by screwing into round or oblong holes.

[0043] If the retaining elements are attached to the substructure in the alternative configuration, and the head profile of a reinforcement profile is inserted into the clamp, the subsequent adjustment remains fundamentally unchanged. The supplementary force-fit fastening (third fastening section or positioning element) can also be logically carried out according to the corresponding concept.

[0044] A special feature of the facade system presented here is the ability to create particularly narrow horizontal gaps between two adjacent facade panels. This is desirable for both aesthetic and functional reasons (weather protection). The limit for gap width in current technology is typically reached when a fastener, such as a screw, must be accessed through the gap between two adjacent facade panels using a suitable tool. While a third fastening point can theoretically be positioned relatively freely during facade construction—fastening beyond the panel edge is not a problem as long as the next facade panel is not installed until afterward—removing an existing facade panel in a finished facade, for example, for repairs, becomes problematic if the fastening point of the damaged panel is concealed by an adjacent panel.

[0045] Furthermore, the head diameter of a fastener such as a screw is usually generously dimensioned because this widening forms a bearing surface and thus plays an important role in the strength of the fastening point. However, if the fastener has a head that is too large in diameter, it can no longer be guided through a (narrower) gap between the facade panels when the fastening point needs to be re-established after a panel in the facade has been replaced.

[0046] Therefore, with the facade system presented here, the vertically measured distances between the horizontal edges of two adjacent facade panels can be selected in the installed state such that the resulting gap is sufficient for inserting and operating a fastening and releasing tool for a fastener. In other words, the head size of the fastener is irrelevant; only the tool dimensions matter. If an existing, installed facade panel is to be removed, a further condition must be met: The tool must be able to release the fastener from the fastening point along its effective length. For this to be possible, the length of the fastener must be shorter than the clear width d between the facing and opposite back surfaces of the facade panel and the mounting surface (taking into account the material thickness of the fastening element, especially the third fastening section).Since, as mentioned several times, the facade panels are fastened via both the clamp (second fastening section) and the third fastening section, the fastener used there can be adapted to the changed load requirements.

[0047] In this description, the focus of the invention has been placed on facade fastening because this is the preferred and most frequent application for the inventive fastening elements. However, if the term "facade" is broadened to include "building envelope" or "building cladding," it becomes clear that the applicability of the fastening elements and the type of facade fastening described here is not limited to vertical exterior walls. Without fundamentally altering the inventive concept, cladding can also be implemented on ceilings, reveals, building passages, driveways, and even interior wall cladding. DESCRIPTION OF THE FIGURES

[0048] Figure 1shows a first embodiment of a retaining element. Figure 2 shows a facade support for vertical mounting, Fig. 2B one variant Figure 3 shows a second embodiment of a retaining element. Figure 4 shows a holding element according to Figure 1 on a facade support according to Figure 2 Figure 5 shows a third design element of a retaining element Figure 6 shows a rear view of the assembly situation of a facade section. Figures 7 to 9 The diagrams abstractly show the components of holding elements, especially the clamps, in cross-section. Figure 10 The image abstractly depicts a trapezoid using the basic geometric elements employed in this description. Figure 11 shows a reinforcement profile in an oblique view Figure 12 shows the profile of Fig. 11 in cross-section Figure 13 The cross-section shows a facade panel with an attached reinforcement profile.

[0049] To facilitate technical understanding, the sequence of figures is described differently below than shown.

[0050] Figure 10 Figure 600 shows an isosceles or symmetrical trapezoid. The two parallel sides have different lengths (long base 610 and short base 620). Figure 10 Figure 1 shows an isosceles or symmetrical trapezoid with two equal angles β between the shorter base 620 and the legs 630 and 640, where the adjacent interior angles of each base are equal in pairs. Therefore, the legs 630 and 640 are also of equal length in a symmetrical trapezoid.

[0051] For the Figures 4 and 7 to 9Coordinate crosses are drawn, which are also used in the figure descriptions. The coordinates are based on the installation position in the preferred mounting configuration, i.e., vertically mounted profiles 700. This orientation corresponds to the "y" direction. The horizontal is designated with "x", while the direction perpendicular to the building surface is designated with "z". The cross-section of a head profile 710, which exhibits the trapezoidal shape, therefore lies in the xz-plane, while the facade panels lie essentially in the xy-plane. Figures 7-9 They are all oriented in the xz-plane.

[0052] The Figure 7 A schematic diagram shows the bracket of a holding element in cross-section; a realization as a complete holding element corresponds to... Figure 1The first spring element 310 is located on the left side, oriented essentially in the z-direction. The mirror-symmetrical counterpart 330 is not shown separately here for clarity, but its position is logically clear from the context. As shown, the clamp encloses the trapezoidal receiving space 350, which, in its installed state, is occupied by the head profile 710 of a facade support (see figure). Figs. 2 and 4 The short base of the trapezoidal receiving space 350, or of the clamp 200 marked with a solid black line, is described by 354, the long base by 352, and the two legs by 356 and 358, respectively. The spring elements 310, 330 are doubly bent at their ends and thus act as a detent device for 380 with two subsections 381, 382. Section 381 is, in the embodiment of Figure 7Section 382 is oriented essentially parallel to the base sides 352 and 354. Section 382 is oriented essentially parallel to the legs 356 and 358, respectively. Section 382 facilitates the sliding of the clamp 200 in the z-direction from the short base side 354. The sections 382 are springily pressed onto the legs of the receiving space 350 (or head profile 710) until they can spring back on the rear side of the head profile 710 / receiving space 350. Figure 7This illustrates the "positive locking in the x and z directions" state in precisely this case. Additionally, the spring force creates a frictional locking in the x, y, and z directions. In the y direction (perpendicular to the plane of the drawing), the clamp 200 can slide if a sufficiently high force overcomes the frictional locking of the clamp 200 in this direction. In the z direction, with a sufficient tensile force, the spring will open again, and the clamp can be pulled off the head profile. It is obvious to those skilled in the art that the length (and angle of inclination) of the sections 381 and 382 can be selected such that the (desired or required) holding effect as well as (practical) assembly can be achieved. This can be determined through simple tests.

[0053] Figure 8 differs from Figure 7 primarily through the design of the locking device 390 and shows the design according to Figure 3By punching out a tongue 391 and bending it towards the central axis 370 (=axis of symmetry) of the clamp 200, a locking device is created that engages behind the trapezoid of the receiving space / head profile 710 as soon as the clamp 200 is slid onto the head profile 710 from the narrow side (short base 354). This design variant cannot be released by pulling it away from the head profile 710; thus, both a positive locking and a frictional locking mechanism exist in the x and z directions. Manual intervention or the use of a tool is necessary for unlocking.

[0054] In Figure 8The two dimensions B 200 and B 710 are also shown. B 200 refers to the length of the base of the clamp 200 in the internal dimension, corresponding to the short base side 354 of the trapezoid in the x-direction. B 710 denotes the width of the front surface of the head profile 710 in the x-direction (horizontal). In the actual design, when a clamp 200 is installed (regardless of whether it is designed according to...) Figure 7 or 8 ) the head profile 710 encloses, in the case of positive locking in the x-direction, B 200 will be chosen to be equal to or slightly larger than B 710 - taking into account manufacturing tolerances.

[0055] The situation is somewhat different in Figure 9 , where a bracket 200' is shown with a combination of spring tongues according to Figures 7 and 8. This technically theoretically possible, but not practical, hybrid is only intended to illustrate a principle that is possible for both spring tongue variants. As in Figure 9As can be seen, length B 200 and width B 710 are no longer approximately equal; rather, the width B 200 of the clamp is larger than B 710. This means that while a tongue 391 or a section 381 can still engage a head profile 710 (receiving space 350), the clamp has play in the x-direction. The lengths of section 381 and tongue 391 can be easily determined geometrically by a specialist who knows the size of the trapezoid. This clamp variant thus loses the positive locking in the x-direction but still exhibits the frictional locking effect caused by the spring action. The clamp therefore exerts a holding effect on the head profile but allows for the compensation of installation inaccuracies, for example, if the horizontal spacing of the facade supports 700 deviates from the specified dimension. This can be achieved through a combination of holding elements / clamps according to... Figures 7 / 8 and 9The installation of a facade panel 500 can be carried out by sliding it onto the facade supports 700 and then the retaining clips can be used to secure it. Figure 9 The permissible play is used for fine adjustment and alignment. Final fixing is achieved using the tabs 450 (see Figure 5 ), which, depending on the fastening method, then create either a fixed point or a sliding point. The existing frictional connection between the clamp and the head profile remains unchanged.

[0056] Figure 2Figure 710 shows a section of a facade support or vertical profile 700 in perspective cross-section. The head profile 710 points forward to the left in the figure, and the mounting surface 760 faces forward. The width of the head profile B 710 is indicated. The profile 700 shown here resembles a railway track profile, but this is not mandatory. The functional elements are a wall base 750 for attachment to a load-bearing building surface and a spacer 730, which defines the distance between the building wall / wall base 730 and the head profile 710. The profile 700 shown is a single piece, but it can also be modular and consist of long profile head elements (similar to reinforcement profile 800) and individual brackets for transferring the load to the building wall. The substructure is typically determined by the type, size, and weight of the facade panels, as well as local building regulations, fire protection requirements, and thermal insulation standards.

[0057] Figure 2Bshows a variant 700' of the vertical profile 700 from Figure 2 The above applies to the basic structure in the form of a railway track; therefore, most of the reference symbols are identical. The only difference here concerns the head profile 710', which, instead of a closed trapezoidal structure, has a largely T-shaped structure that is semi-open towards the wall base 750. Functionally, this head profile 710' interacts with the inventive retaining elements in the same way as the vertical profile 710. Figure 2 In comparison, less material is used for production and the manufacturing process is simplified, while maintaining comparable stiffness of the structure.

[0058] The Figures 1 and 3 Retaining elements 100 with two clamps 200, 200' according to Figure 7 respectively. Figure 8The retaining elements in both figures have a first fastening section 150, which is flanked by two second fastening sections 300, which in turn consist of clamps 200, 200' with spring elements 310, 330. The first fastening section 150 is designed here as an elongated, U-shaped metal part in cross-section with several elongated holes. Fastening to a facade panel 500 is achieved through these elongated holes such that the openings of the clamps 200 point away from the back of the facade panel. The U-shape of the fastening section 150 fulfills two functions: Firstly, it stiffens the fastening section in the longitudinal direction, and secondly, it creates a recess for rivet or screw heads so that these do not protrude into the mounting surface 760. As can be seen from Figure 4As becomes clear, the connecting piece 320 between a first and second spring element 310, 330 lies flush against the mounting surface 760 in the installed state. This is only guaranteed if the fastening elements between the retaining element 100 and the facade panel 100 can be recessed.

[0059] The embodiment of the spring elements 310 and 330 differs between Figures 1 and 3 The embodiment according to Figure 1 follows this Figure 7 explained operating principle, Figure 3 the of Figure 8 . Figure 3 The figure further illustrates the position and spatial direction of the central axis 370. To the expert, it would be clear from a perspective standpoint that the central axes of both brackets together define a plane of reflection. The dimension B 200 for the narrow side of the trapezoid is also indicated (see explanations of the Figures 7-10 ), which here also describes the length of the connecting piece 320.

[0060] In Figure 3One can see how the locking devices 380 and 390 were implemented. These can be produced cost-effectively as stamped and correspondingly bent tabs. Figure 1 shows the variant with a double-folded dropout of the spring element.

[0061] Figure 4 shows a simplified vertical profile 700 without wall base 750, with a holding element 100 according to Figure 1 , without facade panel. As can be seen, the head profile 710 is clamped by the two spring-loaded fastening sections 300, 300', thus ensuring a positive fit. The spatial directions are marked with a coordinate cross. The mounting surface 720 and the connecting piece 320 are flush, as are the spring elements 310, 330 (not marked in Figure 4The first fastening section has a series of elongated holes / fastening bores 180. Between these and the mounting level 760 there is a space for the retaining heads of the fasteners to attach to the (here omitted) facade panel.

[0062] The in Figure 5 The holding element shown corresponds to the clamp operating principle of Figure 9 with lateral play and angled ends 380, 390 and is in Figure 6 Shown in its installed state. Figure 5 This shows two special features: The first fastening section 150 is simultaneously a connecting piece 325 with a spacer 327. The spacer is implemented as a cranked cutout in the connecting piece 325 and fulfills the same function as the U-shaped version of the fastening section 150 in the Figures 1 and 3The connecting piece 325 has holes for the fasteners to the facade panel. The heads of the fasteners must not serve as a bearing surface against the mounting surface 760; this function is therefore performed by the spacer 327. For reasons of tilt stability, it will be implemented in at least two versions (in Figure 5 (covert).

[0063] The second special feature is the design of the third fastening section 400, shown here with a simple fastening hole 420 and two elongated holes 440.

[0064] The third fastening section 400 is designed as an (here) asymmetrically arranged, tongue-shaped tab 460. In other words, the tab 460 projects from the base body of the retaining element 100 in the y-direction, i.e., the direction that, in the installed state, is parallel to the vertical profile 700. When positioned on a facade panel, the tab 460 will project beyond the edge of the panel to allow for final fastening (see description above). Figure 5 The tab is arranged such that it lies beyond the central plane of symmetry (analogous to...). Figure 8 , Figure 3The reason for this is that a second identical retaining element can thus be arranged in a mirrored position, so that both tabs lie next to each other on the mounting plane. This allows for tighter gaps between two adjacent facade panels. A 470° offset compensates for the difference in distance between the connecting piece 325 and the mounting plane 760 in the installed state.

[0065] The result illustrates Figure 6 with such a mounting situation of two facade panels 500 and 500'. Front 510 and back 520 are labelled. A simplified vertical profile 700 with head profile 710 is shown. The latter is enclosed by clamps belonging to two retaining elements 100, 100'. In the drawing, it can be seen that both clamps are of the functional type according to Figure 9with lateral play. The tab 460 of the lower retaining element 100' is visible in the drawing; it projects upwards and is accessible through the gap 540.

[0066] Figure 11 shows a reinforcement profile 800 in a 3-D view, shown from the side intended for mounting on the back of a facade panel. Figure 12 shows the same profile in a cross-section. The reference symbol 810 marks a trapezoidal head profile 820, analogous to the head profile 710 in Fig. 4 or 2B The base section 850 is designed here as a U-shaped component, but can be designed in an alternative / equivalent manner. Its dimensions are determined by the type and size of the brackets and the specifications of the wall structure.

[0067] Figure 13Figure 1 shows an embodiment of a mounting situation of two reinforcement profiles 800, 800' on the back 520 of a facade panel 500 in cross-section. The free space created by the base section, into which clamps 200 can snap during installation, is clearly visible.

Claims

1. Retaining element (100) of a facade fastening device, which serves to attach a facade panel (500) to a facade support (700) by means of the retaining element (100) arranged between them, wherein the retaining element (100) has a first and a second fastening section (150, 200) which are mechanically rigidly connected to each other, wherein a spring-loaded connection or clamp (200) is used in the second fastening section (300); and this clamp (200) has a pair of elements which form between them a receiving space (350) open on one side for the at least force-fit or form-fit and force-fit accommodation of a head profile (710, 810) of a facade support (700) or a reinforcement profile (800), wherein the receiving space (350) has a trapezoidal cross-sectional shape with a long base side (352) and a short base side (354), wherein the short base side (354) is arranged parallel and adjacent to the first fastening section (200) and the opening of the receiving space (350) is located near the long base side (352), characterized in that the pair of elements is a pair of spring elements (310, 330) arranged symmetrically to each other with respect to their center axis (370).

2. Retaining element (100) according to claim 1, characterized in that the spring elements (310, 330) of the clamp (200) are substantially designed as two resilient tongues and are aligned along the legs (356, 358) of the receiving space (350).

3. Retaining element (100) according to claim 1-2, characterized in that the spring elements (310, 320) further have locking devices or retaining means (380, 390) such as cams, embossed portions, or tongues that can engage with correspondingly designed surface features of a head profile (710, 810) of a facade support (700) or a reinforcement profile (800).

4. Retaining element (100) according to claim 1-3, characterized in that the second fastening section (300) has two clamps (200, 200').

5. Retaining element (100) according to claim 1-4, characterized in that stop / contact surfaces, drill holes, and / or elongated holes are provided on the first fastening section (150) in order to create a force-fit and / or form-fit connection between the retaining element (100) and a facade panel (500) or a reinforcement profile (800) or a facade support (700) fastened to the facade panel (500) by means of fasteners such as screws, rivets, or adhesives.

6. Retaining element (100) according to claim 1-5, characterized in that a third fastening section (400) is also provided as a component of the retaining element (100), which enables a non-spring-loaded connection between the retaining element (100) and the facade support (700) and which is rigidly connected to the first fastening section.

7. Retaining element (100) according to claim 6, characterized in that the third fastening section (400) is designed as a tongue-shaped tab (460), which in turn has stop / contact surfaces, drill holes, and / or elongated holes, which, by means of fasteners such as screws, rivets, or adhesives, enable a force-fit and / or form-fit connection between the retaining element (100) and the head profile (710) of a facade support (700) on its mounting surface (760).

8. Retaining element (100) according to claim 1-7, characterized in that the clamp (200) is manufactured as a bent or molded part made of metal, in particular spring steel or a tough elastic plastic.

9. Facade, comprising at least one facade panel (500) having a plurality of retaining elements (100) according to claim 1-8 which are attached thereto; a substructure consisting of a plurality of vertically arranged facade supports (700), characterized in that the facade supports have a head profile (710) with a trapezoidal cross-sectional area and a mounting plane (760).

10. Facade, comprising at least one facade panel (500) having a plurality of reinforcement profiles (800) fastened thereto and aligned parallel to one another, as well as a substructure consisting of a plurality of facade supports (700) having a plurality of retaining elements (100) according to claim 1-8 which are fastened thereto, characterized in that the reinforcement profiles (800) have a head profile (810) with a trapezoidal cross-sectional area.

11. Facade according to claim 9 or 10, characterized in that the trapezoidal cross-sectional area of the head profile (710, 810) has a short base side with a width B710, wherein this short base side is oriented in the direction of the opening of the clamp when the head profile (710, 810) and clamp (200) are assembled.

12. Facade according to claim 9 or 10 and 11, characterized in that at least one retaining element (100) is provided, in which the short base side (354) of the receiving space (350) has a length B200 and this length B200 is selected so that it essentially corresponds to the width B710 of the head profile (710), so that when the clamp (200) and the head profile (710) are joined together, a form-fit connection is achieved between the clamp (200) and the head profile (710).

13. Facade according to claim 9 or 10 with 11, characterized in that at least one retaining element (100) is provided, in which the short base side (354) of the receiving space (350) has a length B200 and this length B200 is greater than the width B710 of the head profile (710), so that when the clamp (200) and head profile (710) are joined together, lateral play relative to the vertical is achieved in the mounting plane (760).

14. Method for fastening a facade panel (500) to a substructure consisting of vertical facade supports (700) by means of retaining elements (100) according to claims 6-8, comprising the following steps of: - providing facade panels (500) with retaining elements (100) fastened in accordance with a predetermined installation plan; - providing a substructure attached to a building wall with vertical facade supports (700), also in accordance with the predetermined installation plan; - attaching the facade panels (500) to the facade supports (700) by sliding the clamps (200) of the retaining elements (100) onto the head profiles (710) of the facade supports and clamping around the head profile in a spring-loaded manner; - aligning the facade panel (700) in the intended end position according to installation plan; - fastening individual retaining clamps (100) by force-fit connection of the third fastening section (400) to the mounting surface (760) of the head profile (710).