SYSTEM FOR SECURING PLATEFORMED ELEMENTS ON A SURFACE
The present invention concerns a system for securing slab- formed elements, e.g. stone slabs such as slate elements or slate slabs, for mainly even surfaces. A preferred area of use of the securing system is for fastening such ele¬ ments on vertical surfaces such as walls of buildings. The system is also suited for securing elements to inclined surfaces, and is also suited for use with elements of unequal thickness.
Slab-formed elements of metal, artificial fabric or stone are used for covering outer walls of buildings as a pro- tection against the influence of weather, and is a so- called "outer skin", because the material of such slabs is very resistant to erosion caused by the weather and thus is more suitable than for instance wood or similar kinds of materials. Further, elements of stone, artificial fabric of stone and metal are practically maintenance-free compared with lighter wall-covering materials. The problem with using stone or metal in such elements, however, has been the weight of the elements, making special securing systems necessary for the plate elements. An "outer skin" of the type described above is generally used only as a protection against weather erosion, and thus the elements are preferably mounted in such a way that there is a space between the slab elements and the supporting wall or the inner wall, which is the wall which forms the insulation against the rooms behind. The inner wall is also equipped with a water-rejecing outer layer to be able to resist some weather erosion but need not be especially resistant since it is protected by the "outer skin" comprising the mentioned slab elements.
Since the slab elements being fastened with the securing system according to the present invention form a facade,
it is also an objective of the invention that the outer wall surface is smooth without protruding sections, and at the same time is looking good. It is also an objective of the present invention to produce a securing system which is very versatile and where it is possible to carry out maintenance and replacement of slab elements in the wall surface separately and individually.
Systems for securing slab-formed elements to surfaces are known from the literature. Such a system is known from EU patent 208.229 and NO patent 127.158 concerning an anchor¬ ing element for securing or hanging slabs of artificial or natural stone. The disadvantage of this type of prior art securing systems is that in the elements or slabs to be secured, holes or grooves must be drilled for the holding parts of the securing system. This will weaken the slab elements and in addition will make it necessary to pre- treat them before mounting, this representing extra work and costs as well as a complicating factor for the mount- ing itself.
Systems are also known where the slab elements may be used without any significant pre-treatment before being mounted Thus, from EU patent 39.950 and NO patent 169.301 securing systems are known based on carrying rails where the slab elements are secured by using carrying brackets or carry¬ ing elements for the rails. Such systems are, however, not very adaptable, both concerning the placing of the slab elements, which have to be in coloumns or rows since they are dependent on the carrying rail system, and they are also very sensitive to variations in the thickness and shape of the slabs, since the securing brackets must be adapted to the thickness of the slab elements or vice versa. Furthermore, it will be difficult to carry out repairs or replacements of the slab elements in the facade without having to demount large parts of the facade.
Contrary to this, a securing system according to the present invention permits changing of the position of each slab element and at the same time makes it possible to perform maintainance or replacements of each and any element in the facade independently from each other, and the system also makes it possible to use slab elements with varying thickness (and possibly shape) and still achieve a wall facade displaying a smooth outer surface.
The securing system according to the present invention will be explained below under reference to the accompany¬ ing drawings, wherein:
Figure 1 a-e shows the parts of the securing system according to the present invention in one embodiment of the invention.
Figures 2 - 4 show the assembly of the parts from fig. 1 a-e of the securing system according to the invention.
Figure 5 shows the assembled securing system with the parts shown in figure 1 a-e according to the invention, with indicated secured slab elements for a facade.
As mentioned above, Figure 1 a-e show the elements of the securing system according to the present invention. The securing system thus comprises a vertical securing rail 1 (Fig. la) with a u-shaped profile, where one leg 2 of the u-shaped profile l preferably is somewhat longer than the other leg 3. The longest leg 2 of the profile is equipped with a number of holes or securing organs 4,5 for securing this vertical rail to the carrying wall or surface (not shown) for the carrying system. The securing means 4, 5 for the rail 1 may be bolts or screws in the case where these means 4, 5 are holes penetrating the leg 2 of the profile 1, but they may also be other known securing devices such as welded hooks etc. (not shown) .
The short leg 3 of the u-formed rail profile 1 is secured to a horizontal rail 6 (Fig. lb) which also comprises a u- for ed profile where one leg 7 of the profile of the rail 6 preferably is somewhat longer than the second leg 8 of the profile of the rail 6, even it this is not strictly necessary. The advantage of equipping the rail profile 6 with a longer leg 7 is obtaining a possibility for better attachment to the vertical rail 1. The horizontal rail 6 is equipped with securing organs 9, 10 for attachment to the vertical rail 1. Such securing means may for example be holes for securing bolts (not shown) , but the horizon¬ tal rail 6 may also be attached to the vertical rail 1 by welding, such as point welding, in the points 9, 10 of the securing means. It is also possible that in another embo- diiment of the invention the rail parts 1 and 6 are made in one piece, such as by direct casting if an artificial material for the rails is used. The choice of material for such rails may be made by the person skilled in the art, preferably the rails are made of extruded aluminium.
The carrying construction for the securing parts (Fig. 1 c-e) for the slab-formed elements of the wall facade is the horizontal rail 6 (Fig. lb) , and it may be possible to secure the carrying system for the elements according to the invention directly onto the carrying wall by using the carrying rail 6 via the securing points 9,10 on the elongated leg 7 of the rail profile. Such an attachment alternative will, however, give little room for airing between the slab elements constituing the outer wall and the insulating inner wall, and therefore is generally not preferred, even if such an alternative may be possible with the suspension system according to the invention. Attachment of the slab elements by using the vertical rail 1 in addition to a horizontal rail 6 will also improve the draining of water which may penetrate the aperture between each facade element or which may occur due to
condensation in the space between the facade and the inner wall.
The parts for carrying the slab elements of the outer facade wall are shown in Figure 1 c-d. The carrying part
11 shown in Figure lc is the part which carries the weight of the slab elements in the outer wall. This part 11 is designed as a backwards and upwards bent cramp or hook forming a u-shaped profile wherein the slab elements of the outer wall are placed. The bottom 12 of the u-shape of the lower carrying part 11 is wide enough to receive at least the thickest element of the slab parts of the outer wall layer. In this way all the other and thinner slab elements may be upheld by such a carrying part 11. The two ends of the carrying part 11 in their turn are bent back¬ wards, so that they form between themselves a groove which is suited for the short leg 8 of the u-profile of the horizontal carrying rail 6. The distance between the bent sections 13 of the carrying part 11 is not critical, but it is preferred that it forms at least a supporting sec¬ tion for the slab part being secured with this element of the securing system. It is also. possible to use several such lower carrying parts 11 for the same slab element.
Figure Id shows a supporting element 14 in the form of a cramp or hook substantially similar to the lower support element 11. The backwards bending of the cramp, however, has here been made in such a way that the profile of the cramp or hook is s-shaped with a middle downwards bent section instead of an upwards bent section as in the carrying hook 11. Again the supporting element comprises a carrying section 15 which is at least of the same width as the widest slab element which is to be carried by the attachment system according to the invention. At each end 16 of the carrying hook 14 there is another backwards bent section, so that between themselves they form a groove for attachment over the smallest leg 8 of the carrying rail 6.
The width of this cramp or hook is not critical. The figu¬ res show that the upper supporting element 14 is narrower than the lower supporting element 11, so that they may be mounted inside of each other (see Figures 4 and 5) , but there is nothing to prevent the two cramps from being designed such that their fitting is reversed. It will also be possible to alternate the legs of the hook so that they are staggered with respect to each other when mounted according to the securing system of the invention. The upper cramp or hook will, when mounted, form an upper support for the slab elements in the wall covering, and in this way it cooperates with the lower support element to keep the slab cover properly in place.
Figure 4 shows an embodiment of the carrying system accor¬ ding to the invention with a slab-shaped element 17 moun¬ ted. In such an embodiment of the invention slab-shaped elements 17 of substantially the same thickness will be used, where the supporting areas 12, 15 of the claws or hooks 11, 14 are adjusted to the thickness of the element
17 or vice versa. In such an embodiment the lower carrying claw or hook 11 supports the weight of the element 17, and the retaining hook 14 holding the upper edge of the ele¬ ment below (see Fig. 5) is responsible for securing and locating of this lower element 18, but does not carry the weight of the elememt 18.
In such an embodiment as shown in Fugure 4, the elements 17 will be held in place by their own weight, and it is usually not necessary to secure the elements further, even if gluing or welding to the holding claws 14, 11 may be possible, although not preferred.
Another alternate method of securing slab elements 17 with the securing system according to the invention is shown in Figure 5, wherein an extra securing element 19 is mounted on the short leg 8 of the lower carrying rail 6. Such a
securing element is shown in detail in Figure le.
With reference to Figure le, the securing element 19 is designed as a resilient element with resilient legs 20, 21. Preferably the resilient legs 20, 21 end in flat sec¬ tions 22, 23 which in a mounted condition abut against the backside of the slab element 17 (see Fig. 5) . The resili¬ ent element 19 is also preferably equipped on its backside with a securing peg 24 which may be placed over the short leg 8 of the lower carrying rail 6, preferably between the holding claws or hooks 11, 14 being shown in Figure 5. Using this resilient action, the securing element 19 will press the slab element 17 against the respectively upwards or downwards bent section of the holding claws 11, 14, and thereby any variation of the thickness of the slab ele¬ ments 17 will compensated by the resiliency of the resili¬ ent element 19. The resilient element 19 is also pressing the slab elements 17 out against the protruding sections of the holding claws 11, 14, and thus the outer surface of the facade will be decided by the length of the carrying sections 12, 15 of the holding claws 11, 14, and not by the thickness of the slab elements 17, 18. This will form a smooth outer surface with slab elements of varying thickness.
Since the slab elements are carried by the system shown in Figures 4 or 5 alone, any slab coloumn of the facade will be independent from the adjacent coloumn, and thus the securing system according to the invention will give great variation opportunities for designing a facade structure, and it is not dependent on any rigid and extensive rail system for mounting the slab elements.
When replacing or maintaining the slab elements in the facade it is possible with the securing system according to the invention to quickly and easily replace individual elements. This can be done by shifting the holding claws
11, 14 (optionally together with the resilient element 19) in the horizontal direction until the securing claws 11, 14 and the holding spring 19 become displaced past the side of the one side edge of the slab element 17 to be replaced. By removing these parts of the securing system it will be possible to replace or maintain each and any of the slab elements individually, and a remounting of the slab may be done by performing the above indicated actions in reverse. For this purpose, as well as for estethic reasons, it will be preferred to mount the slab elements in the facade with a distance between them, also in the horizontal direction.
The invention has been disclosed above with reference to the embodiment shown in the figures, but variations and alternatives will be obvious to the person skilled in the art without departing from the inventive concept behind the present system.