The invention is related to a system comprising a rectangular panel and a supporting structure to which the panel is attached by means of at least one connection element having two portions, wherein one of these portions is a part of the panel and the other portion is a part of the supporting structure, and wherein one portion of said connection element comprises a first member being rotatable around an axis of rotation extending parallel with an edge of the panel, and wherein the other portion of said connection element comprises a cylindrical metal bar extending parallel with said edge of the panel, and whereby said rotatable first member is engaging said cylindrical metal bar at its surface opposite of its surface facing said axis of rotation.

Such a system is disclosed in publication WO 2016/102452 describing a system wherein a rectangular panel is attached to a supporting structure by means of connection elements provided with a rotatable hook having an axis of rotation parallel to an edge of the panel. The supporting structure comprises elongated support elements being provided with cylindrical metal bars to be engaged by the rotatable hook of the connection element.

The system can be used for attaching panels in a vertical plane, in a horizontal plane and in an inclined plane. Thereby, the front surface of the panels can be located in a flat plane, or the panels can have a tiled relationship, whereby a panel has an overlap with a neighbouring panel. For example, the outer surface of an existing building can be covered with panels in order to improve the appearance of the building. Or an old or damaged wall can be covered by plates of high pressure laminate, being a material that can have any color or combination of colors, and being a weather resistant material. The outer surface of a new building, or a part of the outer surface, can be formed by such plates, whereby the panels are an integrated portion of the building.

The system can be used for attaching any kind of panel to a supporting structure, but in particular, the system can be used for installing solar panels against the outer surface of a building, or for making solar panels an integrated portion of the outer wall or roof of a building. The system can also be used for installing panels apart from a building, for example on the ground, and forming an inclined surface of a number of solar panels. Because these panels are often located outside in a free surrounding, the temperature fluctuations of the panel may be relatively high. When attaching a panel to a supporting structure by means of connection elements, there may be a problem caused by a difference in expansion of the materials of the panel and of the supporting structure due to changing temperatures. Such difference in expansion may cause undesired stress in said materials. In order to solve said problem, connection elements allowing a movement of the panel in its plane can be used. Such connection member is disclosed in WO 2016/102452, whereby a cylindrical metal bar of the supporting structure can shift in a member of the panel. However, when the two metal surfaces of a connection element slide against each other, the surfaces will wear. In particular when such connection element should have a long lifetime without maintenance, it is important to minimize damage in the connection elements.

An object of the invention is a system comprising at least one rectangular panel and a supporting structure to which the panel is attached by means of connection elements, wherein a long-lasting reliable connection between the panel and the supporting structure is obtained.

Another object of the invention is a system comprising at least one rectangular panel and a supporting structure to which the panel is attached by means of connection elements, wherein after attaching the panel to the supporting structure, a part of the panel can move with respect to the supporting structure in a direction substantially parallel to the plane of the panel, whereby wear of parts of the connection elements is minimized.

In order to comply with one or both of these objects, said at least one connection element comprises a rotatable second member, wherein both members are rotatable around a common axis of rotation and wherein said first member and said second member are both engaging said cylindrical metal bar. Thereby, said first and said second member can engage said cylindrical metal bar in a manner that both members will rotate around said cylindrical metal bar when the panel moves with respect to the supporting structure, substantially in its plane.

In a preferred embodiment of the invention, the portion of the connection element comprising said rotatable first member and said rotatable second member is a part of said panel, and said cylindrical metal bar is a part of said supporting structure, so that the supporting structure does not comprise moving parts. Preferably, two of said connection elements are present, wherein all of the four members are rotatable around the same axis of rotation, and wherein the two cylindrical metal bars have coaxial axes. These two connection elements can be located near an edge of the panel, whereby two different connection elements are located near the other edge extending parallel with said edge. These two different connection elements should attach the panel to the supporting structure without the possibility of movement

Publication WO 2016/102452 shows such different connection elements, whereby a rotating member engages a cylindrical metal bar in a manner that no movement of the panel with respect to the supporting structure is possible.

Furthermore, the invention is related to a rectangular panel to be attached to a supporting structure and comprising a portion of at least one connection element for connecting the panel with the supporting structure, said portion comprises a first member being rotatable around an axis of rotation parallel with an edge of the panel, wherein said rotatable first member is able to engage a cylindrical metal bar being a part of the supporting structure, wherein said portion comprises a rotatable second member, and wherein both members are rotatable around a common axis of rotation, so that said first member and said second member are both able to engage said cylindrical metal bar. The engagement of the cylindrical metal bar results in a connection whereby the panel can move a bit substantially in its plane, at the location of the connection element.

In a preferred embodiment of the invention said rotatable first member is provided with a flat surface for engaging said cylindrical metal bar for creating a rolling movement between the first member and the cylindrical metal bar, not a sliding movement, so that the surfaces of the cylindrical metal bar and the first member do not wear. This will be further elucidated hereinafter with reference to figure 4 of the drawing. Preferably, said second member is made of a synthetic material, so that it can move around the cylindrical metal bar without causing wear and tear.

In a preferred embodiment of the invention, the panel comprises portions of two of said connection elements, each portion having a rotatable first member and a rotatable second member, wherein said four members have a common axis of rotation. Preferably, said second member is made of a synthetic material, so that it can move around the cylindrical metal bar without causing wear and tear.

In a preferred embodiment of the invention, the panel is provided with a rectangular front plate and whereby the edge of the front plate is the edge of the panel. In particular if the panel is a solar panel being used for creating a surface of a wall or roof, it is an advantage to have not a visible frame around the panels.

In a preferred embodiment of the invention, the panel comprises at least one profile beam at the back side of the panel, the profile beam extending parallel with the plane of the penal and perpendicular to said edge of the panel, wherein said portion of a connection element is located at least substantially in the interior of said profile beam, so that after the cylindrical metal bar is engaged by the two rotating members, the cylindrical metal bar passes at least substantially through the interior of said profile beam. Thereby, the rotatable members are located inside the profile beam, so that they are protected against damage when handling the panel.

Furthermore, the invention is related to a method for attaching a rectangular panel to a supporting structure by means of at least one connection element having two portions, wherein one of these portions is a part of the panel and the other portion is a part of the supporting structure, whereby a first member of one of these portions is rotated around an axis of rotation extending parallel with an edge of the panel, so that said first member engages a cylindrical metal bar at its surface opposite of its surface facing said axis of rotation, said cylindrical metal bar being a member of the other portion of said connection element and extends parallel with said edge of the panel, whereby a second member of said connection element is rotated around said axis of rotation, so that said first member and said second member are both engaging said cylindrical metal bar. Preferably, said first member and said second member are parts of said panel and said cylindrical metal bar is a part of said supporting structure.

Preferably, said second member is made of a synthetic material, so that it can move around the cylindrical metal bar without causing wear and tear.

The invention will now be further elucidated by means of a description of a method for attaching a rectangular panel to a supporting structure, whereby reference is made to the drawing comprising schematic and diagrammatical figures showing a portion of the panel and a portion of the supporting structure comprising a cylindrical metal bar, whereby:

Figure 1 shows the situation whereby the panel is brought into contact with the supporting structure;

Figure 2 shows the situation whereby the rotatable second member engages the cylindrical metal bar; Figure 3 shows the situation whereby the rotatable first member engages the cylindrical metal bar, and

Figure 4 shows the panel in its final position with respect to the supporting structure.

The figures show a portion of a metal beam 1 of a supporting structure to which a rectangular panel 2 is being attached. The metal beam 1 is provided with a cylindrical metal bar 3 extending perpendicular to the beam 1 and parallel with the rectangular front plate 4 of the panel 2. The edge of the front plate 4 is the edge of the panel 2. The panel 2 can be a solar panel, whereby the front plate 4 comprises photovoltaic cells. Furthermore, the panel 2 comprises a profile beam 5 having a rectangular transverse section and extending parallel with an edge of the panel 2. The profile beam 5 is attached to the front plate 4 by means of a glue layer 6.

The panel 2 comprises a first member 7 being rotatable around a cylindrical shaft 8, which shaft 8 is fixed in the profile beam 5, so that the first member 7 is substantially located in the interior of the profile beam 5. First member 7 is provided with a flat surface 15 at the location where first member 7 comes into contact with the cylindrical metal bar 3. The angle of rotation of the first member 7 is limited by the edge of an opening 14 in the wall 9 of the profile beam 5. Furthermore, the panel 2 comprises a second member 10 also being rotatable around the shaft 8. The profile beam 5 is provided with a rod 11 reaching in the interior of the profile beam 5, so that the second member 10 can rest against the rod 11. Spring means (not shown in the figures] are present in order to push the second member 10 against said rod 11.

Figure 1 shows the situation whereby the panel 2 is brought into contact with the supporting structure in order to be attached to the metal beam 1. Subsequently, the panel 2 is moved in the direction indicated by the arrow 12, so that the second member 10 comes in contact with the cylindrical metal bar 3 of the supporting structure, as is shown in figure 2. By moving the panel 2 further in the direction of the arrow 12, the second member 10 will rotate around the shaft 8, whereby it will break away from the rod 11, as is shown in figure 3. Thereby, the cylindrical metal bar 3 is engaged by the first member 7 as well as by the second member 10.

Figure 4 shows the situation after the panel 2 is rotated as indicated by the arrow 13 in figure 3, so that the front plate 4 of the panel 2 extends parallel with respect to the metal beam 1 of the supporting structure. The connection element comprising the cylindrical metal bar 3 of the supporting structure and the first and second rotatable members 7,10 of the panel 2 allows a movement of the panel 2 substantially in the length direction of the metal beam 5. During such movement a surface of the cylindrical metal bar 3 and a surface of the rotatable second member 10 will slide along each other. When the material of the cylindrical bar 3 is metal and the material of the second member 10 is plastic, such sliding movement will not result in damage of said surfaces.

Because the material of the cylindrical metal bar 3 as well as the material of the first rotatable member 7 is metal, a sliding movement between surfaces of these parts should be excluded in order to prevent these surfaces from wearing. Because the first member 7 can make a (limited) rotation, a sliding movement between said surfaces is prevented. It works as follows.

When the panel 2 will be displaced a bit upwardly (in figure 4), the cylindrical metal bar 3 will roll over the flat surface (15) of the first member 7 in downward direction with respect to the member 7. Thereby the member 7 will rotate a bit in clockwise direction. And when the panel 2 will be displaced downwardly, the cylindrical metal bar 3 will roll over the flat surface (15) of the first member 7 in upward direction with respect to the member 7, whereby the member 7 will rotate a bit in anticlockwise direction. So, in case of small movements of the panel 2 with respect to the supporting structure 1, there will be no sliding movement between the first member 7 and the cylindrical metal bar 3.

While the invention has been illustrated in the figures and the foregoing description, such illustration and description are to be considered illustrative and exemplary and not restrictive; the invention is not limited to the disclosed embodiment.