Field of the Invention

The present invention is related to the installation of panels on a wall, such as panels having a decorative function and mounted on the exterior surface of buildings. The present invention more specifically relates to an attachment system for the installation of panel, to a support bracket for use therein and to cladding systems comprising the panel and the support bracket or the attachment system.

State of the art.

Decorative panels are often produced from fibre cement, and may be provided with a textured front surface for decorative purposes and a smooth back surface. The panels are mounted on an exterior wall with the requirement that no or very limited traces are observable of the attachment means applied to attach the panels. Attachment systems in use today include systems wherein hangers are fixed to the back surface of a panel, allowing the panel to be mounted on a framework of vertical and horizontal support profiles (also referred to as rails) mounted on the wall. While these systems are effective and show no outward trace of the attachment means, the use of vertical and horizontal rails represents an important material cost and increases the complexity of the installation procedure. The hangers are attached to the back of the panel by bolt connections or by clamping the hangers into horizontal grooves processed in the back surface of the panel. However, this makes the re-use of a panel difficult or impossible, as it may require drilling additional holes or processing additional grooves into the back of the panel. The hangers also represent fixation points which do not allow for expansion of the panel in the height direction, as a consequence of important temperature changes for example. This may cause excessive stress build-up in the panel, possibly leading to crack formation. Some systems use only horizontal support profiles directly fixed to the wall, but this requires very accurate attachment of these profiles to the wall, which can easily lead to incorrect installations. Also, using only horizontal rails may restrict the dimensions of the cavity behind the panels, leading to problems in terms of the required airflow in such cavities.

A further type of attachment system is known from KR100751487B1 on a fastening apparatus for an exterior panel of a building, and particularly Fig. 1 and 2 thereof. This known attachment system was widely in use according to the description of said patent. A panel is therein provided with a pair of grooves on its rear side. A bracket comprising a first and a second support profiles, that each includes a base portion with a flange extending into the grooves of said pair of grooves. Each of the support profiles further comprises a wall portion extending away from the panel. The two support profiles are mutually secured together by means of a screw, at a predefined distance of each other. The first support profile further comprises transversal portions extending from said wall portion in two opposed directions. The first transversal portion defines the predetermined distance. The second transversal portion is arranged parallel to the base portion and configured such that a U-shaped end of the profile on the wall can be clamped therebetween. The flanges are each provided at an end of the base portion. A sharp angle is present between the flanges and the base portions. In fact, the grooves in the panel are not parallel but are arranged such that their tips are closer to each other than the apertures. Therewith, the flanges will anchor into the panel. By tightening the screw, the fixation will be strengthened.

A disadvantage of the known attachment system is the need to define grooves into the backside of the panel under different and oblique angles. This is cumbersome and may easily lead to manufacturing losses. Moreover, the resulting tip in the fiber cement board is vulnerable and may crack, break off or disintegrate under the applied forces. It is herein relevant that the grooves extend in the horizontal direction. Therefore, the lower bracket will carry a lot of weight, which equally applies to the tip that constitutes the contact area with the lower bracket. A further disadvantage is the stability of the bracket, as the mutual attachment is arranged only by means of the transversal portion. This transversal portion would provide a counterforce against too strong tightening of the screw.

Moreover, silicone materials are deemed necessary for spaces between and/or around the profiles of the bracket. These silicone materials get contaminated and aged due to external environment such as external temperature and rainwater. This causes water leakage and condensation. Moreover, the screw that secures the profiles of the bracket together is a simple coupling bolt, which is sensitive to the impact of moisture and heat. As a consequence, there are many problems such as extremely difficult repair and replacement of the building exterior material.

Summary of the invention

The invention aims to provide solutions to the above problems. This aim is achieved by an attachment system, a bracket, an installation method and a cladding system as disclosed in the appended claims.

The invention relates in particular to a support bracket and an attachment system therewith for the attachment of one or more panels provided with pairs of mutually parallel grooves through the back surface of the panels while not going through the full thickness of the panel.

The attachment system comprises a plurality of support profiles and a plurality of support brackets. The support profiles are configured to be fixed to the wall, for instance vertically, and shaped so that part of the support profiles extends outward from the wall when the profiles are fixed thereto. Said outward extending part is configured for attachment to one of said brackets. The support brackets are formed of a first and second bracket profile configured to be assembled by inserting respective leg portions of the bracket profiles into the grooves of a pair of grooves, and by securing wall portions of the bracket profiles to each other, thereby assembling the bracket and simultaneously clamping the bracket in said grooves.

According to the invention, each bracket profile comprises a base portion, a leg portion and a wall portion. The base portion configured to be arranged on the back surface of the panel. The leg portion extending outward from the base portion and configured to be inserted in one of the two parallel grooves of one of the pairs of grooves, such that upon assembly, the profiles of a bracket jointly clamp into said pair of grooves. The wall portion extending outward from the base portion in the opposite direction of the leg portion. The wall portions of the bracket profiles of one bracket are configured to be arranged and secured together along a major surface of each of said wall portions, thereby realising simultaneously the assembly of the support bracket and the clamping thereof into said pair of grooves.

The support bracket and the attachment system according to the present invention provide a robust attachment of a panel to a wall, in a manner so that both the attachment system and the grooved panels can be manufactured at high yield. The alignment and arrangement of the wall portions of the bracket profiles along their main surface facilitates robustness. The presence of wall portions and leg portions on opposed sides of the base portion increases strength. As a consequence, it is not deemed necessary that the grooves are arranged into the back side of a panel according to oblique and mutually different angles. Furthermore, the structure of the brackets allows for the brackets to be made sufficiently high so that the cavity behind the panels can be large enough to provide a required airflow.

One specific advantage of the invention resides therein that the grooves may be arranged into the fiber cement board in a vertical direction. Hence, the brackets will be exposed to equal force and pressure. Evidently, this requires strong clamping, since the fiber cement panel could otherwise glide along the groove. This requirement is however met by the bracket of the invention.

In one preferred embodiment, the wall portions of the first and second bracket profile have a mating shape with at least one of the profiles having a protruding element and the other a corresponding depressed element. This has turned out to facilitate strength without hindering the assembly of the bracket profiles. Preferably, at least one of the depressed element and the protruding element is longitudinal and extends in a direction parallel to the base portion. It is therein preferably, but not necessary that the depressed element and the protruding element have exactly the same shape. The depressed element could be a channel or a combination of channels. The protruding element could be a small feature fitting within the one or more channels. The fixation could be improved in that a plurality of protruding elements is used. One specifically preferred combination is a ridge and a groove.

Suitably, the leg portion extends from the base portion so as to divide the base portion in a first and second part on opposed sides of the leg portion. So, otherwise than the prior art flange, the leg portion does not extend from an end of the base portion, but really from a side face thereof and preferably at a rectangular angle with the base portion. However, the wall portion extends from the base portion at an end thereof.

The leg portion is preferably provided with a series of teeth, so as to increase fixation into the groove of the panel. It has been found that a limited number of teeth, for instance 1-5, is preferable, with up to 3 teeth being most preferable. The exact shape of the teeth is open to design and may depend on the manufacturing method of the bracket profile as well as on its material and on the material of the panel. The teeth may have sharp points but could alternatively be block-shaped, like teeth in the mouth of a human being. Furthermore, the design of the individual teeth within a single bracket profile may be distinct. Particularly, a first tooth placed to get deeper into a groove than a second tooth may have wider dimensions than said second tooth. The teeth are preferably arranged in a direction towards the other groove. This position is most beneficial for the clamping strength.

Various options are envisaged for the attachment of the support profile on the wall to the bracket. A support profile with an L-shaped cross-section is well- known, and hence, the bracket may be provided with at least one transversal portion to attach and secure the second, bottom leg portion of the L-shaped cross-section. The support profile may alternatively be fork shaped, such as disclosed in Fig. 3-5 of the above-mentioned patent KR100751487B1 . Again a further alternative resides in a connection wherein the support profile and the bracket are provided with mutually mating connector shapes. It will be apparent to the skilled person to extend the one or two brackets in a manner so as to accommodate the various options.

In one advantageous embodiment, at least one of the bracket profiles, and preferably both, is further provided with transversal portions, configured to form a half-closed space as seen in cross-section, enabling to slide the second leg portion of the support profiles into said half-closed space, when a panel provided with the assembled brackets is shifted horizontally. At least two of the brackets attached to a panel are provided with elongated portions configured to extend beyond the upper edge of the panel, enabling the fixation of these brackets and thereby of the panel to the vertical support profiles attached to the wall. Herein, the support profiles comprise at least a portion having an L-shaped section comprising a first leg portion and a second leg portion, so that the support profiles may be attached vertically to a wall with the second leg portion oriented at a (non zero) distance from the wall and parallel thereto.

The attachment system of this embodiment requires only vertical support profiles fixed to a wall and thereby represents an improvement over many existing systems in terms of material cost and installation complexity. The grooves are oriented vertically when the panels are installed on a wall, making the exact positioning of the brackets in the height direction of the panel less critical. The mounting of a panel is straightforward, as the correct horizontal position is automatically reached when the leg portions of the support profiles become inserted into the half-closed spaces of the brackets when the panel is shifted horizontally with respect to the vertical support profiles.

In one further implementation, only the support brackets mounted near the upper edge of the panel are fixed, for example by screw connections, to the support profiles, while the lower brackets are not secured to said profiles in the vertical direction while still maintaining the panel at a fixed distance from the wall. This means that the panel is free to expand and retract in the height direction so that stress build-up and cracking is avoided.

The grooves are preferably made significantly longer than the length of the brackets, providing much flexibility in terms of the positioning the brackets. This makes it also easier to re-use a panel as the re-positioning of brackets requires no additional processing of the panel.

The bracket profiles are preferably made by means of extrusion, and more preferably comprise a metal, so as to ensure sufficient strength. Aluminum is a preferred choice. However, it is not excluded that use is made of composites, such as matrix materials reinforced with particles and/or fibers. Alternatively manufacturing techniques such as insert molding, transfer molding and 3D- printing are not excluded.

Any of the embodiments that are discussed hereinabove and/or hereinafter and/or defined in the dependent claims in relation to one aspect of the invention, such as the attachment system, are also applicable and deemed disclosed to the other aspects of the invention, such as the bracket, the method and the cladding systems.

Brief description of the figures

The figures illustrate exemplary embodiments only and are not limiting the scope of the invention. Equal reference numerals are used in different figures to refer to equal or corresponding elements.

Figure 1 shows the outer appearance of a wall provided with a panel attached by a system according to an embodiment of the invention.

Figure 2 shows the main components of the system applied to attach the panel shown in Figure 1.

Figure 3 shows the panel provided with support brackets, before mounting the panel to the wall.

Figures 4a and 4b represent a 3D view and a section view of one of the support brackets.

Figure 5 illustrates the steps applied for mounting a bracket to the back surface of the panel.

Figure 6 illustrates how a panel may be moved to its mounting position by shifting the panel horizontally while being supported by a preliminary support.

Figures 7a and 7b illustrate the horizontal shifting movement of the panel, as seen from above.

Figures 8a and 8b illustrate alternative shapes of a support bracket applicable in a system and method according to the invention.

Detailed description of preferred embodiments of the invention

Figure 1 shows a single panel 1 mounted on a vertical wall 2, in accordance with an embodiment of the invention. Only one panel is shown in order to illustrate the invention, but it is to be understood that in most cases the wall is to be fully covered by multiple panels, with a small clearance between adjacent panels.

As seen in Figure 1 , the attachment system of the illustrated embodiment of the invention comprises, apart from the panel 1 , a plurality of L-sectioned support profiles 3 which are mounted vertically on the wall 2. The way in which the L-profiles 3 are fixed to the wall is not shown, but this may be done in any way known in the art, for example by attaching the L-profiles to anchors fixed to the wall. Regardless of how the L-profiles are mounted, the cross-section of each of these profiles 3 comprises a first leg portion 4 that is essentially perpendicular to the wall 2 and a second leg portion 5 positioned at a distance from the wall 2 and oriented essentially parallel thereto. Any support rails equivalent to an L-profile, in terms of comprising the first and second leg portions 4 and 5 can be used, for instance T-profiles or U-profiles with one of the upstanding legs of the ‘U’ fixed to the wall 2. What counts is that an ‘L-shaped section’ of the support profiles 3 extends outward from the wall, said L-shaped section comprising the leg portions 4 and 5 oriented as described above. The support profiles 3 may be profiles that are already known today for use as vertical or horizontal support rails, i.e. no dedicated support profile design is required. The length of the leg portions 4 and 5 may be equal to each other or slightly different, as is the case in the enclosed drawings. As seen in Figure 1 , the panel 1 is attached to the second leg portion 5 of two adjacent profiles 3 by two connections 6, preferably screw connections.

Figure 2 is a view from the top, revealing the additional attachment means hidden behind the panel 1. It is seen that four support brackets 10 are attached to the back surface of the panel 1 . Each bracket 10 is mounted into a pair of mutually parallel grooves 11 , and the brackets are coupled to the second leg portion 5 of the support profiles 3, in a manner that will be detailed further in this description. To explain how the brackets 10 are shaped and assembled, reference is made to Figures 3 to 5. Figure 3 shows the panel 1 with the four brackets 10 attached thereto, before the panel is mounted to the wall. The panel 1 may be a fibre cement panel having a thickness of about 8 mm for example, although the invention is applicable to panels of all sizes, thicknesses and materials. Typical thicknesses of fiber cement panels are in the range of 5-20 mm. In the particular embodiment shown, it is seen that four pairs of mutually parallel grooves 11 have been processed into the back of the panel 1 . In general, a minimum of one pair of mutually parallel grooves can be used depending on the size of the panel and engineering design calculations. At least two pairs is preferable. In an 8-mm panel, the depth of the grooves 11 is preferably about 5 to 6 mm deep. The grooves have parallel side walls extending essentially perpendicularly to the back surface of the panel 1 . The length of the grooves 11 is sufficient for receiving the brackets 10 therein, preferably exceeding the length of the brackets to a considerable degree, so that some flexibility is provided for the placement of the brackets 10 in the length direction of the grooves 11. In the embodiment shown, the pairs of grooves 11 are aligned along two lines A and B which will be oriented vertically when the panel 1 is mounted to the wall. The two brackets mounted close to the upper edge 13 of the panel comprise elongated plate portions 12 which extend beyond said upper edge 13. The extending ends of these plate portions 12 are visible in Figure 1. Through these ends, the connections 6 are applied for attaching the panel 1 to the support profiles 3. Near the lower edge 14 of the panel, two brackets 10 are mounted which are not provided with the elongated portion 12.

Before explaining how the panel 1 is mounted to the wall, the brackets 10 are described in more detail as well as the manner in which the brackets are assembled. Figure 4a shows a detailed view of one of the brackets 10 mounted near the lower edge 14 of the panel 1 . The bracket consists of an assembly of two profiles 15 and 16, which may be formed of extruded aluminium for example. Each profile comprises a number of plate-shaped sub-portions, starting with a base portion 17, a leg portion 18 extending downward from about the middle of the base portion 17, and a wall portion 19 extending upward from the edge of the base portion 17.

The wall portions 19 are designed, so that two wall portions 19 will fit together when they are placed against each other. More particularly, the wall portions 19 are additionally provided with means for arranging and/or securing them to each other. Such means for arranging the wall portions 19 may be of geometrical nature, enabling a user to put the wall portions together in a manner that they fit. In one specific implementation, the wall portions 19 are provided with mating features, more particularly a protruding element 20 and a correspondingly located depressed element 21. In the illustrated embodiment, these are embodied as ridges 20 and respective grooves 21 which fit together when the wall portions 19 are placed against each other, with the base portions 17 at the same level. As shown in the Fig 4a, 4b, 5a and 5b, more protruding and depressed elements 20, 21 may be present. In the shown example, there is a first and a second ridge 20 and corresponding groove 21 , oriented parallel to each other and to the base portion 17. While not illustrated, the surfaces of the wall portions 19 or part thereof, may be further machined to vary in height along the ridge or groove. Such structure hampers movement between the wall portions in the direction of the groove. The wall portions 19 further comprise facing holes 22 through which connectors 23 are inserted which secure the profiles together. These connectors may be rivets 23 as shown, or they may be bolt connections, screw connections or any other suitable connector type. Preferably, the connectors are configured that they do not extend beyond the wall portions when properly installed.

The width and height (in the direction perpendicular to the base portion 17) of the leg portions 18 are matched to the width and depth of the grooves 11 so that the leg portions 18 can be inserted manually in said grooves, preferably being able to be inserted fully in the grooves 11 , so that the base portions 17 are lying against the back surface of the panel 1 . In the embodiment shown, the leg portions 18 of the profiles are provided with gripping teeth 30 extending along the full length of the leg portions 18, the teeth 30 being present on the mutually facing sidewalls of the leg portions 18. Still in the embodiment shown, said mutually facing sidewalls comprise a first portion 31 near the base portion 17 of the respective profiles, the first portion having no teeth produced thereon, followed by the three teeth 30. This way of producing the teeth 30 has been proven optimal in the case of a fibre-cement panel and represents a preferred embodiment of the teeth 30 on the leg portions 18. For a panel having a thickness of about 8 mm, it is preferable to provide three teeth as shown, wherein the width of each tooth is of the order of 1 mm. For thicker panels, the number of teeth having this same width may be increased. The invention is however not limited to this embodiment, but includes embodiments involving other configurations and dimensions of teeth or equivalent gripping aids, as well as leg portions that are not provided with gripping aids, and which are clamped mainly by friction between the leg portions 18 and the sidewalls of the grooves 11 .

The bracket profiles 15, 16 of the illustrated embodiment further comprise transversal portions at the top of the wall portions 19 (i.e. at the side opposite the base portions 17). The first profile 15 comprises a transversal portion 24 that is a rectangular plate element oriented essentially perpendicularly to the wall portion 19 of the first profile 15. The second profile 16 comprises a transversal portion comprising a first plate portion 25 extending at an obtuse angle from the wall portion 19 of the second profile 16, the latter wall portion being shorter (as seen in the direction perpendicular to the base portion 17) than the wall portion of the first profile 15, and at the top of the angled portion 25 a planar portion 26 that is essentially perpendicular to the wall portions 19 of both profiles 15 and 16 (i.e. essentially parallel to portion 24) and that forms an acute angle with the angled portion 25. The latter planar portion 26 of the second profile 16 is located at a higher level from the base portions 17, compared to the transversal portion 24 of the first profile 15 so that the transversal portions define a half-closed space 27 into which a planar plate element can be slidably inserted. The term ‘half- closed’ is applicable to the cross-section of the assembled bracket 10, as illustrated in the section view of Figure 4b : the space 27 is open on the side of the first bracket 15, and closed on the side of the second bracket 16. As seen in the drawing, the space 27 is preferably closed on said latter side by a short wall portion 32 that interconnects the portions 25 and 26.

The assembly of the brackets 10 is illustrated in Figures 5a to 5c, illustrating the assembly of one of the brackets mounted close to the upper edge 13 of the panel, and comprising the elongated portion 12. In this embodiment, the elongated portion 12 is a uniform extension of the transversal portion 24 of the first profile 15. According to other embodiments, the elongated portion 12 could be a separate piece attached to the bracket before or after its assembly. As illustrated in Figures 5a and 5b, the profiles 15 and 16 are placed together manually, by placing the ridges 20 of the first profile 15 into the corresponding grooves 21 of the second profile 16, and with the holes 22 of the two profiles facing each other. The leg portions 18 of the profiles 15 and 16 are then inserted in the grooves 11 of one of the groove pairs, as illustrated in Figure 5b. In the length direction of the grooves 11 , the profiles are placed in such a way that part of the elongated portion 12 extends beyond the upper edge 13 of the panel 1 (as shown in Figure 3). Possibly a positioning aid could be used in the form of a block or other object having the desired length of the extending portion, so that the block may be placed against the upper edge 13, thereby allowing to position the profiles correctly with respect to said upper edge. Alternatively, a marker could be produced on the elongated portion 12 itself, so that the marker can be aligned with the upper edge 13 for correctly positioning the profiles in the grooves 11.

When the profiles 15 and 16 are correctly positioned in the grooves 11 , they are secured to each other by inserting rivets 23 into the matching holes 22, thereby pulling the profiles towards each other and clamping the leg portions 18 in the grooves 11 , as shown in Figure 5c. The teeth 30 are pulled against the walls of the grooves 11 , ensuring thereby a sufficient clamping force.

All the brackets 10 are assembled and thereby attached to the back surface of the panel 1 in this way, resulting in the panel as shown in Figure 3, provided with four brackets 10. The mounting of the panel 1 to the wall 2 is illustrated in Figures 6 and 7. As shown in Figure 6, an auxiliary profile 40 is preferably used. This auxiliary profile 40 may be an L-profile as shown, that is temporarily attached to the vertical support profiles 3, for example by manually attachable and removable clamps (not shown), and positioned horizontally, preferably with the aid of a spirit level, at the required position of the lower edge of the panel 1. The panel 1 is placed on the auxiliary profile 40 and shifted horizontally. This is illustrated in the top view shown in Figure 7a. The transversal portions 24 of the brackets 10 are placed in contact with the second leg portions 5 of the support profiles 3, and then the panel is moved horizontally, until said leg portions 5 slide into the half-closed spaces 27 of the brackets 10, as illustrated in Figure 7b. At this point, the panel is correctly positioned horizontally, and maintained at a fixed distance from the wall 2 at four locations by the brackets 10. At this point also, the elongated portions 12 of the brackets 10 overlap the second leg portions 5 of the support profiles 3. The technician can then secure the panel 1 to the wall 2 by the connections 6 through said portions 12 and through said leg portions 5, as shown in Figure 1 . These connections 6 may be any suitable fastening means, such as self-drilling screws for attaching metal plate elements without pre-drilling. Nevertheless, pre-formed holes may be present in the elongated portions 12 of the brackets to enable the use of other types of fasteners. The attached panel is thereby suspended from the support profiles 3 at two positions only, along the upper edge of the panel, leaving the panel free to expand and contract in the height direction.

As indicated already in a number of instances, the invention is not limited to the embodiment shown in the drawings. The shape of the brackets may be different, within the boundaries of the characteristics included in the independent claims. For example, the transversal portions 24 and 25/32/26 of the profiles 15 and 16 could have a different shape, while still allowing the second leg portion 5 of the support profiles to be inserted in the half-closed space 27 defined by said transversal portions. A few examples of such alternative shapes are shown in Figures 8a and 8b. In both drawings, the half-closed space 27 is indicated into which the second leg 5 of the support profiles 3 may be slidably inserted. Various other alternatives may be devised by the skilled person, all falling within the scope of the present invention.

The number of brackets 10 applied to a panel 1 may be different than four. More than four brackets may be required for attaching a large panel for example.

The panels 1 are preferably planar rectangular panels as shown, but they may include shapes other than rectangles, as well as panels with a certain curvature. Such panels may either be attached to similarly curved wall surfaces or the support brackets 10 may be adapted to the curvature of the panels, for example by orienting the leg portions 18 not perpendicularly to the base portions 17 but at an angle corresponding to the curvature of the panel at a given position.