ITGE20090007A1 - PANEL FOR FORMWORN CONTAINMENT WALLS FOR CONCRETE CUTS IN PARTICULAR FOR THE CONTAINMENT FORM OF CONCRETE OR SIMILAR INSOLES - Google Patents

Description

"Formwork retaining wall panel for concrete casting, in particular for retaining formwork for concrete slabs or similar"

TEXT OF THE DESCRIPTION

The invention refers to a panel for the construction of formwork containment walls for concrete casting, in particular for containment formwork for the construction of concrete slabs or the like, which panel is made up of at least one load-bearing layer of wood which is externally coated at least partially with one or more layers of sealing and / or protection against humidity and / or water, the load-bearing layer being in turn formed by at least two layers, of which at least a first layer is made up of a plurality of strips having a predetermined length, which strips are made with the fibers of the wood oriented in the longitudinal direction of the strips themselves and which strips are glued to each other in a to form said first layer in which they are arranged with the longitudinal axes oriented in a direction substantially parallel to each other, being the head sides of the load-bearing layer and of the panel oriented transversely to the direction of orientation of the wood fibers of the strips and / or to the longitudinal extension of the strips themselves, while the longitudinal side edges of the load-bearing layer and therefore of the panel are oriented parallel to the direction of orientation of the wood fibers of the strips and / or to the longitudinal extension of the strips themselves,

The containment formworks for concrete castings are known and are formed by a plurality of panels which together form the concrete containment walls with the desired shape and dimensions and which panels are mounted in such a way as to form said containment walls in a supporting structure.

As indicated above, each panel is composed of at least one supporting layer of wood having dimensions of length, width and thickness such as to resist without deforming the stress of the concrete and at the same time, however, to present a certain ease of handling by the personnel assigned to transport and when assembling the formwork. These dimensions, especially as regards the thickness, are substantially fixed. Therefore, the problem currently exists of how to increase the load resistance of the panels without modifying their thickness and in particular without increasing their thickness.

Panels of the above type having at least one layer with a blockboard structure are known and the strips are mainly made of resinous wood. Although the panels made from resinous wood strips guarantee weight reductions compared to panels made mainly of hard wood and therefore more compact, these panels do not allow to obtain sufficient mechanical resistance characteristics according to the safety standards in the building field for low thickness and weight. .

In fact, in order to give greater mechanical resistance to the panel, it is known to make the wooden part, i.e. the load-bearing layer in the form of two or more layers, in which the strips of one layer and those of the adjacent layer are arranged crossed together. regarding the direction of the wood fibers.

It is known to protect the load-bearing layer of wood along at least some lateral edges and / or parts of some lateral edges as well as along at least a part of at least one of the two faces thanks to a coating layer in waterproof material such as resins, films or layers of plastic or the like.

In particular with regard to the construction of formwork walls for slabs, the panels must have sufficient resistance to bending under the weight of the concrete. In wooden strips, their resistance is greater in the longitudinal direction of the wood fibers than in the transverse direction. Furthermore, the cost of the panel and the weight must be contained, therefore we try to limit unnecessary processing steps. Since the absorption of liquids and in particular of water and humidity in the wood is decidedly lower by the surfaces oriented parallel to the direction in which the fibers are oriented than by the surfaces oriented transversely to the fibers, exploiting the fact that the formats of the panels provide rectangular shapes, in some known panels these characteristics have been exploited to create panels with a load-bearing layer with a blockboard structure in which the strips are made with their longitudinal axis oriented in the direction of the wood fibers, while the transverse head edges of the laths extend transversely to the orientation of the wood fibers. In this case, any sealing and protection layers are provided on the two faces of the panel, that is of the load-bearing layer and along its transversal edges, since the strips are oriented with their longitudinal axis parallel to the longitudinal axis of the panel and then the fibers oriented parallel to the longitudinal axis of the panel itself. The load-bearing layer is therefore formed by a plurality of adjacent strips arranged at least on one layer, i.e. coplanar with each other and oriented with the longitudinal axes parallel to the wood fibers and parallel to the longitudinal direction of the panel, since the adjacent strips are side by side. and joined by chemical / physical adhesion, or by gluing at the longitudinal edges of mutual contact.

Even in the case of this panel, however, the mechanical resistance to load in the transverse direction to the longitudinal axis of the panel is insufficient relative to what is required by the safety standards of the sector, so the load-bearing layer must be made of several layers of strips, without therefore obtaining a solution to the problems common with the other known panels.

The invention has the purpose of realizing a panel of the type described at the beginning which, thanks to simple and inexpensive measures, can have characteristics of resistance to stress on the panel itself which, at the same thickness of the panel, are better than those of the panels. existing panels, effectively obviating the drawbacks of the existing panels and that is allowing an effective protection of the panel both against mechanical damage and against damage to the seal against infiltration of water or humidity, all without requiring cost increases or excessive structures complex and without increasing the manufacturing steps, especially relating to the sealing of the load-bearing layer against moisture infiltration.

The invention achieves the above purposes thanks to a panel of the type described at the beginning and that is a panel for the construction of formwork containment walls for concrete casting, in particular for containment formworks for the construction of concrete slabs or similar, which panel is made up of at least one load-bearing layer of wood that is externally coated at least partially with one or more layers of sealing and / or protection against humidity and / or water , being the load-bearing layer formed in turn by at least two layers, of which at least a first layer is made up of a plurality of strips having a predetermined length, which strips are made with the fibers of the wood oriented in the longitudinal direction of the strips themselves and which strips are glued to each other so as to form the said first layer in which they are arranged with the longitudinal axes oriented in a substantially direction body parallel to each other, being the head sides of the load-bearing layer and of the panel oriented transversely to the direction of orientation of the wood fibers of the strips and / or to the longitudinal extension of the strips themselves, while the longitudinal side edges of the load-bearing layer and therefore of the panel are oriented parallel to the direction of orientation of the wood fibers of the strips and / or to the longitudinal extension of the strips themselves, in which at least the second layer of wood that forms the load-bearing layer is made up of a sheet of wood, the fibers of which are oriented in a transversal direction to the longitudinal extension of the panel or strips and / or in a transversal direction to the direction of orientation of the fibers of the strips being the two layers coupled together by gluing and being at least part of a head side of the panel oriented in the direction transversal to the direction of the wood fibers of the strips that form the first str consists of a sealing edge which is of plastic material, and overlaps the top side of the load-bearing layer and / or the sealing and / or protection layer (s) along at least said part of said head side and is fixed to the said head side of the panel by means of chemical / physical adhesion and sealing it towards the outside.

A first advantageous embodiment provides that the load-bearing layer consists of three layers of material of which: two first layers of material which are each made up of a plurality of strips and which form the outermost layers of material and a second layer of material which It is interposed between the two first layers of material. The said three layers of material are coupled together in a superimposed position on top of each other by gluing or by other means of chemical / physical adhesion.

An executive variant also provides that the load-bearing layer is made up of three layers of material of which in this case, however, two layers of material each consist of a second layer of material formed by at least one sheet of wood, while between the same ones are An intermediate layer is interposed which is constituted by a first layer of material formed by a plurality of strips, since the said three layers are coupled together in a superimposed position on top of each other by gluing.

Advantageously, the sheet of wood which forms the second layer or layers of material of the load-bearing layer is made of a hard wood.

According to a further characteristic, said sheet has wood fibers oriented substantially parallel to each other along the entire surface extension of the sheet and parallel or substantially parallel to at least one of the peripheral edges and / or transversely with respect to a further peripheral edge.

According to a preferred characteristic, the wood sheet which forms the second layer or layers of material of the load-bearing layer has a thickness lower than that of the first material layer of the load-bearing layer, i.e. lower than the thickness of the strips forming the said first layer of material. In particular, said sheet of wood can have thicknesses between 1 and 8mm, preferably between 1 and 4mm.

The second layers of material can also consist of at least two sheets of wood which are glued together in a relative position such that they have a crossed orientation between them of the wood fibers, so that the orientation of the wood fibers is for one of said sheets transversal to that of the wood fibers in the layer formed by the strips, while for the other of the sheets the wood fibers extend substantially parallel to the wood fibers of the strips.

The wooden sheets can be made according to any different techniques. According to a preferred embodiment, the sheets of wood are so-called veneers, that is, obtained from a log by means of the peeling process.

Thanks to the above characteristics, the invention allows to obtain considerable advantages:

The thin layer or layers of hard wood, that is the aforementioned wood sheets or the aforementioned veneers, guarantee a resistance to transversal bending, since at least one of said layers has wood fibers parallel to each other and oriented in the transverse direction of the panel. With the same thickness of the layers formed by the sheets, i.e. of veneer, the resistance to transversal bending is particularly high and in any case greater than that obtainable with layers of blockboard wood even with structures that have two or three layers of blockboard wood in which the strips of the various layers are oriented transversely to each other with reference to the direction of the wood fibers. The above is valid both at the same thickness and also with thicknesses of the load-bearing layer according to the present invention that are smaller than those of the load-bearing layers in the known panels.

Furthermore, considering having fixed overall thicknesses, in the realizations with blockboard wood, the surface of the transversal head fibers is such as to determine a high water absorption, while using a layer of veneer or more layers according to the present invention, it is obtained at the at the same time a reduction in the absorption of water along the longitudinal edges, and an increase in the resistance to transversal bending at the same thickness with the corresponding layers in the completely linear panels.

In addition to this, the use of hard wood sheets, or layers of hard wood, have given surprising results as regards the torsional strength of the panel. In fact, this resistance is greater than that which can be obtained by using only layers with a blockboard structure both at the same thickness and also with thicknesses of the load-bearing layer according to the present invention that are smaller than those of the load-bearing layers in the known panels.

Furthermore, from the point of view of the mechanical characteristics, the load-bearing layer provided in the panel according to the present invention guarantees greater dimensional stability both with respect to panels with load-bearing layers with blockboard structure and to panels with load-bearing layers made of plywood.

With reference to absorption, thanks to the fact that the layers formed by one or more sheets of wood such as veneer or similar are made of hard wood, the absorption of moisture by these layers at the edges of the said layers oriented transversely to the direction of orientation of the fibers is very low and negligible. The fact that the wood sheets are thin helps to further limit absorption. This allows to have edges of said sheets which are oriented transversely to the direction of orientation of the fibers and which coincide with the longitudinal edges of panels which are provided with seals only along the transversal head edges and not along the longitudinal edges of the panel, without there is a greater absorption than the part of the said longitudinal edges of the panel formed by the strips oriented with the wood fibers parallel to the said longitudinal edges of the panel itself.

In this case it is advantageous and preferable that the fibers of the strips are oriented 100% in a direction parallel to the longitudinal axis of the strips and therefore to the longitudinal axis and to the longitudinal edges or of the longer sides of the panel.

The definition of hardwood means woods such as Maple, Alder, Birch, Hickory, Hornbeam or white beech, Chestnut, Beech, Ash, Walnut, Sycamore, Poplar, Cherry, Willow, Oak, Linden, Elm and also tropical woods such as Pine kauri, Iroko, Red pine, Rosewood, Brazilian Rosewood, Ebony, African Mahogany, Mansonia, Balsa, Nyatoh, Afrormosia, Meranti, Teak, White Frakà ̈, Ayous.

As regards the protection and sealing of the panel, or rather of the load-bearing layer against moisture infiltration, said load-bearing layer is advantageously covered on one or both faces with a layer of protection material and in particular of sealing , a groove or groove being provided, at least along a part of the sides of the panel along which the sealing edge is provided, which groove extends directly below the side of the protective layer or layers adhering to the load-bearing layer of the panel and which groove is delimited at least on one side by said side of the corresponding protective layer, while the sealing edge also extends inside said groove adhering by chemical / physical adhesion also to the bottom and side walls of the groove.

One embodiment provides that the groove extends for the entire thickness of the load-bearing layer and is delimited on both sides by the two opposite protection layers being the head side of the load-bearing layer recessed with respect to the head sides of the two protection layers .

In a further executive variant, the groove has a thickness corresponding to a part of the thickness of the load-bearing layer and is delimited laterally on one side by the corresponding protective layer and on the other side by the surface parallel to the protective layer of a step recess which is made along the corner area of the side of the load-bearing layer which is directly underneath the protection layer, while the bottom of said groove is constituted by the step of said step-like recess in the load-bearing layer.

In practice, the protective layer covers the step recess towards the outside, leaving a perimeter band corresponding to the depth of the milling or the step recess uncovered or accessible from the groove.

The sealing edge, on the other hand, has a filling extension of said groove and adheres by means of chemical-physical adhesion to the walls of the groove formed by the material of the supporting layer and of the protective layer.

An improvement provides that when the carrier layer is covered with a protective layer on each of the two opposite faces, then a groove of the above type is provided having a partial thickness with respect to the overall thickness of the carrier layer directly below each of the two protective layers and along the sides in correspondence of which the sealing edge is provided, in this case the sealing edge being provided with filling extensions of each of said two grooves which extensions adhere by chemical / physical adhesion to the materials of the boundary walls of the grooves.

A further improvement provides that the protective layer or layers are made of plastic material and that the sealing edge adheres tightly against the head side of the said protective layer or layers and to the side of the said protective layer or layers which constitutes the side wall of the corresponding groove.

Thanks to this expedient, a band of adhesion of the plastic material of the sealing edge to the plastic material of the protective layer or layers which is wider than the simple thickness of said layers is generated in a simple way. This ensures that the path necessary for humidity or water to penetrate from the outside to the supporting layer of wood or similar is longer and extends from the outside of the joint between the sealing edge and the protective layer. to the bottom of the groove for a length corresponding to the depth of said groove.

Still according to a further advantageous improvement, the sealing edge is made by injection molding in particular of PU, whereby the filling extensions of the groove or grooves are absolutely unproblematic.

According to a further characteristic, the panel has a load-bearing layer interposed between two protection layers which adhere respectively to one face of the load-bearing layer, the load-bearing layer being provided with a fin which is central with reference to the overall thickness of the said load-bearing layer and which has a thickness less than the overall thickness of the load-bearing layer, the flap protrudes beyond the corresponding perimeter side of the protective layer or layers and which flap is incorporated into the sealing edge that covers it on the sides parallel to the faces of the panel and on the head side, completing the thickness of the panel until it reaches the overall thickness of the protection layers and the load-bearing layer.

An improvement provides that when the panel has a groove or groove directly under each of the protective layers, which grooves or grooves are constituted by perimeter step recesses of the load-bearing layer, said fin is constituted by a peripheral extension of the load-bearing layer comprised between the two stepped recesses, whereby the surfaces of said fin which are parallel to the faces of the panel extend flush with the corresponding surfaces of the stepped recesses which form said grooves or grooves.

A further advantageous feature provides that in said fins there are provided holes or openings which pass through the thickness of said fin, while the sealing edge penetrates through them with material bridges which connect the two layers of material of said edge which cover the two faces of said fins which are parallel to the faces of the panel.

Thanks to the aforementioned construction, the sealing edge and the material of the protection layer are coupled, which is not only chemical / physical, but also mechanical. The cross bridges of sealing edge material that fill the through holes form a kind of mechanical retaining nails that contribute to the mechanical coupling between the load-bearing layer and the sealing edge. This has a synergistic effect on the coupling between the sealing edge and the protective layers that make up the watertight joint. In fact, the mechanical coupling of the sealing edge to the load-bearing layer prevents displacements of this edge with respect to the edge and therefore tears or cracks in the joint between the sealing edge and the material of the protective layers.

Still according to a further refinement, the step recess that forms the penetration groove or grooves of the sealing edge under the protective layer (s) has a bottom or raised surface that is concave, This optimizes the absorption of the thrusts during the injection of the sealing edge material, preventing the high injection pressures from causing lifting of the protective layer or layers.

Although the sealing edge can be provided along all sides or along any side of the panel, in a preferred embodiment the panel provides that the sealing edges are provided along the leading sides of the panel which are oriented transversely to the direction in which they are orient the wood fibers of the strips.

When, as in the aforementioned case, the edge of the wood layer to which the sealing edge is applied is oriented transversely to the wood fibers at least for part of its thickness, it is obtained that the surface along said edge is rough or in any case porous and irregular, so that a better interpenetration is generated between the said surface of the wood and the plastic material of the sealing edge which therefore improves not only the mechanical anchoring, but also the sealing, generating a barrier to humidity which has a certain depth of penetration into the wood layer.

As far as the protection layers are concerned, these can be constituted by thin films of resins, paints, or the like or by layers of plastic material for example of the type consisting of decayed polypropylene with vegetable flours and known for example by the name of Wood-Stock ®. Said protective layers can be sealed together by means of chemical / physical adhesion to the sealing edges, thus generating a sealing jacket of the internal wood layer which is of plastic or resin material and which is sealed on all sides. sides by means of said chemical / physical adhesion, for example welding, gluing or the like.

In the case of the examples indicated above, the sealing edge is applied to the panel already provided with the wood layer and a covering or protection layer on at least one side, so that during the molding the material forming the sealing overlaps the leading surface of the edge of the wood panel and the corresponding thickness of the edge of the coating and / or protection layer.

Taking into account the fact that the absorption of water or humidity from the surfaces of a batten that are oriented parallel to the wood fibers are negligible, as well as the absorption by the wood sheet (s) or hardwood veneers also when they have wood fibers transversal or perpendicular to the said surfaces, then it results that the sealing against humidity and / or water infiltrations is necessary only along the said two edges of the panel in correspondence with which they are located or which are formed from the head sides of the strips, while the longitudinal or longer sides of the panel can remain uncovered.

Considering the dimensions of the panels that are currently used for the manufacture of formworks and which typically have dimensions with a width of 500mm and with lengths of 1000mm, 1500mm, 2000mm, 2500mm, the panel with the load-bearing layer according to the present invention allows to exploit in the best way to obtain the veneered hardwood formats available on the market.

The above panel therefore has a protective and / or sealing coating on the two opposite faces, and a plastic coating along the shorter peripheral sides, i.e. the sides oriented transversely to the longitudinal extension of the panels themselves and to the ™ orientation of the fibers in the layer or layers formed by the strips. The longitudinal sides of the panel are uncoated and are formed by the wood itself of the three layers.

According to an improvement, the panel can also have a protective coating along said longitudinal sides. This coating has the purpose of protecting said longitudinal sides mainly from mechanical damage.

In particular, in order to allow any humidity that may have penetrated into the wood layers to transpire, since the longitudinal sides are the only parts of the wood material not covered by protective or sealing layers, the invention provides that along the said longitudinal sides the panel has a stepped recess along each corner between the longitudinal side and one of the two faces of the panel, which stepped recess is filled so as to complete the cross section of the panel at said longitudinal sides with a plastic filling that extends with one side flush with the corresponding longitudinal side of the panel and with the other side flush with the corresponding face of the panel, thus forming a longitudinal protective edge along each longitudinal edge of the panel.

Basically, the invention provides that for a certain depth in the direction of the thickness and that for a certain depth in the direction of the width of the panel, the longitudinal edges of the same are formed by a protective edge of plastic material.

In particular, said step recess is filled with plastic material by injection molding, or the plastic edge in correspondence with the longitudinal edges of the panel, is made by injection molding.

Preferably when the panel has an external sealing and / or protection layer on one or both faces, while the corresponding stepped recess extends, in the direction of the thickness of the panel, also for the thickness of the corresponding sealing layer and / or protection itself, whereby the plastic protection edge that forms the corresponding edge of the panel also covers the leading edge of the sealing and / or protection layer.

According to a still further characteristic, the overall dimension of the protective edges at the two longitudinal edges of each longitudinal side of the panel in the direction of the panel thickness is less than the overall thickness of the panel.

In order to have a better anchoring of the protective edges, the step recess has on the side oriented towards the thickness of the panel a groove or groove that extends below the corresponding sealing and / or protection layer, said groove being delimited on one side by the face of the sealing and / or protective layer facing the load-bearing layer of the panel, so that the protective edge also extends for a certain extent in said groove directly below a longitudinal peripheral band of the layer for sealing and / or protection of the corresponding face of the panel.

In the embodiment in which the load-bearing layer consists of three layers of material, of which two outermost layers each consist of a second layer of material formed by at least one sheet of wood, while an intermediate layer is interposed between them It consists of a first layer of material formed by a plurality of strips, since the said three layers are coupled together in a superimposed position on top of each other by gluing, the step recesses along the edges of the longitudinal sides are they extend in the direction of the thickness of the panel for a depth at least equal to the thickness of said outermost layers formed by one or more sheets of wood.

Thanks to this realization, the protective edges of the longitudinal sides of the panel not only allow the transpiration of any humidity that may have penetrated the panel, as they leave free a part of the thickness of the longitudinal sides in which the wood of the load-bearing layer is uncovered. and therefore directly exposed to the environment, but also seal the longitudinal sides of the wood sheets of the two outermost layers, the fibers of which extend transversely to the longitudinal direction and are therefore exposed in a favorable manner to the absorption of the humidity . Therefore, as a third advantage obtained at the same time as the effective protection and the transpiration ability of the panel, the sealing of the longitudinal sides of the layers which have fibers oriented transversely to said sides is also obtained.

Further improvements are the subject of the dependent claims and are described in greater detail below.

The characteristics of the invention and the advantages deriving from them will become clearer from the following description of a non-limiting executive example illustrated in the attached drawings, in which:

Fig. 1 schematically illustrates a plan view of an embodiment of the panel according to the present invention in which the sealing edge is provided only along the leading sides transversal to the wood fibers of the strips which form at least one layer of a load-bearing layer of the panel and around the corner zones, as well as the initial sections of the longitudinal sides adjacent to the said corner zones.

Figure 2 is a perspective view of an embodiment of the load-bearing layer consisting of two layers each consisting of wooden strips arranged with their longitudinal axes and / or with the wood fibers oriented parallel to each other and parallel to the longitudinal direction of the strips themselves and by an intermediate layer consisting of at least one sheet, preferably continuous, of wood whose fibers are oriented transversely to the wood fibers of the strips.

Figure 3 illustrates a cross section of a panel according to Figure 2 and in which the external protection and sealing layers of the two faces of the load-bearing layer are also shown and in which the variant relating to two sheets is indicated with a dashed line. wooden intermediates.

Figure 4A is a perspective view of a variant of the embodiment according to Figures 2 and 3, in which the load-bearing layer consists of two layers each consisting of at least one sheet of wood whose fibers are oriented transversely to the wood fibers of the strips of an intermediate layer formed by wooden strips arranged with their longitudinal axes and / or with the wood fibers oriented parallel to each other and parallel to the longitudinal direction of the strips themselves as well as parallel to the length extension of the panel.

Figure 4B illustrates a cross-sectional view of the panel of Figure 4A also showing the further two protection layers, each of which respectively superimposed on one of the faces of the load-bearing layer.

Figures 5 to 10 show enlarged details of transverse sections of a head side of the panel in correspondence with which a sealing edge is provided according to various executive variants of the invention.

Fig. 11 shows a plan view of the transversal head edge of the panel according to figures 1 and 5 and in which the perimeter flap of the bearing layer protruding beyond the perimeter edge of the protection layer and the through holes provided in said flap is visible , the sealing edge being indicated by dashed lines.

Fig. 12 illustrates an embodiment variant of the panel according to Figure 8 in which the profile of the peripheral edge of the load-bearing layer and of the protective layers has recesses suitable for forming attachment areas for tools for disassembling the panels.

Figure 13 illustrates a detail of a head side of the panel provided with a sealing edge in which attachment inserts for panel disassembly tools are incorporated by drowning.

Fig. 14 illustrates a perspective view on a panel according to Figure 13 in the sealing edge of which said tool attachment inserts are embedded by drowning and which inserts have open tool engagement cavities at the leading side of the edge sealing.

Fig. 15 illustrates a plan view on one face of a panel according to an improvement of the present invention.

Figure 16 illustrates a cross section of the area of a longitudinal side of the panel according to Figure 15.

Figure 17 illustrates, similarly to Figure 16, an embodiment variant of the improvement according to Figure 15.

Fig. 18 shows an enlarged view of a cross section of the area of one of the longitudinal sides of a panel according to a further variant embodiment.

With reference to figure 1, this figure illustrates a panel in particular for formwork of slabs, or the like made according to the invention.

It is important to underline that the examples described in the following description are not to be intended in a limiting way and that these constitute only specific choices between different executive variants, in which the configuration of the panel is a preferred configuration or a configuration from which it is better inventive teaching.

Generally the panels for the construction of formwork have a length between about one and three meters and a width between about 0.5 meters and 1.5 meters, being the length greater than the width (therefore a rectangular shape) and a thickness that varies depending on the materials and the structure from a few centimeters to a maximum of ten centimeters. As regards the above, these are maximum and minimum measurements which also vary according to the configuration of the frame or the bearing frame in which the panels are mounted side by side to create the containment walls of the formwork.

The thicknesses of the panels can vary between thicknesses of the order of magnitude of one or a few decimeters and thicknesses of the order of magnitude of one or a few centimeters.

With reference therefore to figure 1, this illustrates a panel according to a first embodiment of the invention in which the panel has a minimum configuration as regards the number of layers and the number of construction parts.

In this example, the panel consists of at least one load-bearing wood layer 1 which is covered on both sides by a protection and / or waterproofing layer 2 and which also has, along at least the two opposite sides, transversal to the longitudinal axis of the panel and / or to the course of the wood fibers of the load-bearing layer 1 a sealing edge 4 which adheres by means of chemical-physical adhesion to the load-bearing layer 1 and to the protection layers 2, wrapping watertight against humidity and / or water the corresponding head side of the panel load-bearing layer.

The sealing edges 4 extend up to the corner zones of the assembly composed of the intermediate load-bearing layer 1 and the two opposite protective layers 2 and also for a certain length along the two longitudinal sides of the panel with two extensions 104.

The covering and protection layers 2 can be constituted by films of paint or resin or by layers of plastic material in the form of plates applied by gluing or other type of adhesion or anchoring to the wood layer. In particular, the covering and protection layer (s) 2 can consist of polypropylene plates loaded with vegetable flours, for example plates of a material known under the commercial name of Wood-Stock®.

The covering and protection layers 2 of the intermediate bearing layer 1 can also be formed by several layers of material coupled together and which are coupled to the faces of the intermediate bearing layer 1 which, as we have seen, can also be formed by several layers . The thickness of the coating and / or protection layers 2 is included, for example, between a few tenths of a millimeter and a few millimeters and can also reach values lower or higher than those indicated according to the type of coating layer used among those listed above.

In the case of the protection and / or covering layer consisting of polypropylene sheets loaded with aggregates, or the like, the thickness of these layers is in the order of magnitude between a few tenths of a millimeter and a few millimeters.

The coupling of the covering and protection layers 2 to the load-bearing layer 1 can take place after each of these has been obtained from the coupling of further layers or all the layers that form the panel

In these cases, the coating and protection layer (s) 2 are applied before the application of the sealing edge or edges 4, so that when applying these sealing edges 4 the said sealing edges 4 overlap the end sides of the edges of the covering and protection layers 2, connecting to the same so as to generate a sealed joint. The coating and protection layers 2 therefore adhere hermetically to the sealing edges 4 by means of chemical and physical adhesion of the plastic materials that make up the said parts.

The application of the sealing edges can take place with different techniques. A particularly advantageous method is constituted by the technique of injection molding the material of the sealing edge on the corresponding head side of the assembly of the carrier layer 1 and the protective and / or coating layer or layers applied thereto.

Figures 2 and 3 show a first embodiment of the invention. This is a preferred embodiment but which must not be construed as a limitation for possible embodiments derived therefrom. As shown in figure 2, the load-bearing wood layer can be composed of three superimposed wood layers 1A, 1B, 1C, each of which has a predetermined structure. The outermost layers 1A and 1B have a blockboard structure, that is, they are formed by a plurality of strips placed side by side so as to form a continuous layer. The wooden slats can be continuous for the entire length of the wood layer or they can have a shorter length than the length of the wood layer 1A, 1B, since the wooden slats are arranged side by side laterally and longitudinally.

The wooden strips 3 of the individual layers 1A and 1B are arranged with their longitudinal axes oriented parallel to each other, contrary to what happens in the art layer. Each layer of strips 1A, 1B is made up of strips placed side by side and connected by chemical / physical adhesion at the side surfaces of mutual contact. When the length of the laths corresponds to the size of the wood layer in this direction of the laths, then there are no laths placed side by side with each other in the longitudinal direction. Otherwise, the strips are side by side also longitudinally, since the contact head surfaces are oriented transversely to the longitudinal axis of the same provided offset with respect to the contact head surfaces between them of two successive strips in a position laterally adjacent to the former.

Furthermore, the two layers 1A and 1B formed by wooden strips can be arranged vertically aligned with each other with the longitudinal lateral surfaces of mutual contact 103 of the strips of a layer 1A arranged laterally offset and in a position coinciding with an intermediate longitudinal axis of the strips of the layer 1B as illustrated in Figure 3 or with the longitudinal lateral surfaces of mutual contact 103 of the strips of a layer 1A arranged vertically coincident or coplanar with each other with the longitudinal lateral surfaces of mutual contact 103 of the strips of the layer 1B as illustrated in the figure 2.

The individual layers 1A and 1B of wooden strips as well as the wooden strips 3 are glued together in a manner known per se to the person skilled in the art.

According to an advantageous characteristic, the strips are made with their longitudinal axes oriented in the direction of the fibers and therefore of the grain of the wood itself. Thanks to this feature, each strip and consequently the panel has a greater resistance to load with reference to the longitudinal extension of the strips and therefore of the panel since the wood has a greater resistance to stress in the direction of the fibers and veins.

The intermediate layer 1C, on the other hand, is made up of at least one sheet, preferably continuous, that is, without a continuity solution on the surface extension of the panel or of the load-bearing layer 1. The said wooden sheet has a thickness less than that of the layers 1C and 1B formed by the strips and which is of the order from 1 to 8mm, preferably from 1 to 4 mm.

The thin sheet of wood can consist of a so-called veneer. According to a characteristic of the invention, the wood fibers of the wood sheet are oriented to each other parallel to each other and transversely to the longitudinal extension L of the panel.

Said intermediate layer can also be formed by two or more sheets superimposed and coupled together, such as, for example, multilayer plywood sheets or the like. In this case, when the intermediate layer 1C is formed by at least two sheets of wood, the same are arranged in such a way that the direction of orientation of the fibers in one sheet is transverse to that of the fibers on the other sheet. In this case, therefore, one sheet has fibers oriented transversely to the longitudinal sides of the panel or of the load-bearing layer 1, while the other has fibers oriented substantially parallel to said longitudinal sides.

The two or more sheets that can form the intermediate layer 1C are coupled together by means of chemical / physical adhesion such as gluing. This also applies to the coupling of the three layers 1A, 1B and 1C to each other.

Preferably the fibers of the strips that form the layers 1A and 1B are all oriented, that is 100% in the direction of the longitudinal axis of the strips in such a way that the longitudinal side surfaces of the strips that form part of the longitudinal edges of the load-bearing layer have a very low absorption coefficient of liquids and in particular of humidity.

On the other hand, as regards the sheet or sheets forming the intermediate layer 1C, besides being very thin with respect to the thickness of the strips, they have a low moisture absorption thanks to the fact that said sheets or veneers are made of hard wood.

The term hardwood is a technical definition in the specific technical field and examples of hardwood are made up of woods such as Maple, Alder, Birch, Hickory, Hornbeam or white beech, Chestnut, Beech, Ash, Walnut, Sycamore, Poplar, Cherry, Willow, Oak, Linden, Elm and also tropical woods such as Kauri Pine, Iroko, Red Pine, Rosewood, Brazilian Rosewood, Ebony, African Mahogany, Mansonia, Balsa, Nyatoh, Afrormosia, Meranti, Teak, White Frakà ̈, Ayous.

Thanks to the fact that the intermediate layer has wood fibers oriented parallel to each other and transversely to the fibers of the strips that form the layers 1A and 1B, i.e. transversely to the longitudinal edges of the panel, the load-bearing layer 1 and therefore the panel have optimal characteristics of mechanical strength both in longitudinal and transverse direction, and this with overall thicknesses lower than the load-bearing layers of the known panels as well as with considerably lower weights.

In fact, for the strips it is possible to use resinous woods that are not very heavy and inexpensive, while the hard woods for the intermediate layer allow to limit in an acceptable way the absorption of humidity along the longitudinal edges of the panel and to confer mechanical resistance in the transverse direction. of the panel.

The fact of using strips with 100% of the wood fibers oriented in the longitudinal direction of the panel in combination with the limited thickness of the sheet or sheets that form the intermediate layer 1C and the particular type of wood used, such as hard wood, allows to avoid the coating at least of the longitudinal edges of the load-bearing wood layer, 1, since the absorption or penetration of moisture through the surfaces of the strips oriented parallel to the fibers and therefore to the wood grain is considerably lower than absorption and penetration of humidity through surfaces that are oriented transversely to the direction of the wood fibers.

The sides of the wood layer oriented in the transversal direction, that is in the direction of the width of the panel are therefore formed for a considerable part of the thickness by the head sides of the strips which are oriented in a transversal direction to the wood fibers and to the grain of the same.

The sealing edge 4 is applied to the said transverse edges of the wooden panel.

The construction of these is similar to what has already been described previously. The sealing edge 4 applied in particular by over-molding to the head sides of the strips oriented transversely to the wood fibers means that thanks to the greater porosity of these surfaces, the plastic material that forms the sealing edges 4 can penetrate to a certain extent in the pores and between the wood fibers, resulting in an effective sealing action against moisture penetration and also a better anchoring of the sealing edge 4 to the surface of the edge of the wood layer which in addition to the chemical / physical adhesion of the material plastic also generates a mechanical adhesion due to the interpenetration between said plastic material and the wood fibers.

As previously described with reference to Figures 2 and 3, the wood layer 1 or the superimposed layers 1A, 1B, 1C can be covered on their outward facing faces by a covering and / or protection layer 2. The coating and protection layer (s) 2 can be of different type and for example consist of paint, resin or plastic material in the form of film or plates which are joined by chemical / physical adhesion to the faces of the bearing state 1 and that is in this case to the outward facing faces of the two blockboard layers 1A and 1B. The sealing edge 4 overlaps the top surface also of the edge of said coating and protection layers 2 at the edge of the wood layer or layers 1, 1A, 1B to which said coating and protection layers 5 are coupled , by joining said sealing edge 4 with the corresponding edge of said coating and protection layers 5 by means of chemical / physical adhesion.

Obviously, nothing prevents a sealing edge from being provided also at the longitudinal edges of the wood layer or layers 1, 1A, 1B.

In figure 3 the structure of the panel is completed by the presence of said protection layers 2 which are represented schematically, while 101C indicates a sheet that forms the intermediate layer 1C and 101Câ € ™ indicates a second sheet which together with sheet 101C forms the intermediate layer and which may or may not be foreseen and therefore is illustrated with a discontinuous line. This discontinuous line is to be considered as a schematic representation of the fact that the intermediate layer can also be composed of more than two sheets superimposed on each other and coupled by chemical-physical adhesion, such as multilayer plywoods or the like.

Figures 4A and 4B illustrate, similarly to Figures 2 and 3, an executive variant, in which the load-bearing layer of wood 1 is also formed by three layers which are indicated with 10A, 10B, 10C, being unlike the previous form the outermost layers 10A and 10B made similarly to the intermediate layer 1C of the previous embodiment according to Figures 2 and 3, while the intermediate layer 10C has a structure equal to that of the layers 1A and 1B. Here too the load-bearing layer 1 is coated on the two opposite faces with a protection and / or coating layer 2 and from the mechanical and moisture absorption point of view, the panel according to this embodiment has characteristics substantially similar to those of the panel according to the previous example. From the point of view of moisture absorption, the considerations made for the previous executive example also apply in this case. The two outer layers 10A and 10B can be formed by one or more sheets of wood 101A and 101Aâ € ™, 101B and 101Bâ € ™ as the intermediate layer 1C of the previous example being also in this case the wood fibers of at least one of the sheets oriented transversely to the longitudinal edges of the panel.

In both cases the load-bearing layer and therefore also the finished panel have, in addition to greater mechanical strength in the transverse direction of the panel with thicknesses smaller than those of traditional panels, also greater resistance to torsion. This is absolutely unexpected since the wood fibers are generally easily separable from each other in a transverse direction to their longitudinal extension and thanks to a twist, as is easily experienced in person. Contrary to expectations, the panel according to the present invention and the embodiments described above, on the other hand, has a considerable resistance to torsion which exceeds that of traditional panels even with thicknesses smaller than the thicknesses of said traditional panels.

In order to make the watertight junction of the sealing edge 4 with the protective or covering layers 2 of the panel even more reliable against the infiltration of humidity or water, the invention envisages increasing the size of the mortgage surface. contact and chemical / physical adhesion between the sealing edge 4 and the protection and / or coating layers 2 for the part along which said sealing edge extends and in the direction of penetration or the path of water from Outside to inside of the panel through the joint between the sealing edge and the protective and / or covering layers 2.

In the following figures, the structure of the load-bearing layer 1 is omitted for simplicity, which instead must be considered present and realized according to an embodiment among those previously described. Furthermore, the groove or grooves provided immediately below the protective layers 2 can be of such a size in the direction of the thickness of the load-bearing layer 1 as to extend only for at least part or all of the thickness of the outermost layers 1A and 1B or even for a part or for the entire thickness of the intermediate layer 1C. this is similarly valid also for the fin 301 which is formed by the thickness of the intermediate layer 1C or by the entire thickness of the said layer 1C or also by the thickness of one or two outermost layers 1A and 1B.

A first embodiment illustrated in Figure 5 provides that along the head side of contact of the sealing edge 4 against the panel, the intermediate load-bearing layer 1 ends in a predetermined extent with respect to the corresponding edge of the covering layer or layers and / or protection 2. In this way a peripheral groove is formed, the bottom of which is constituted by the head side 101 of the intermediate load-bearing layer 1 of wood or the like and whose lateral delimitation walls are constituted by the perimeter bands 102, of the layers of protection 2 which protrude beyond the head side 101 of the supporting intermediate layer 1.

The sealing edge 4 therefore has an extension flap or rear flap 204 with which it engages in said peripheral groove of the panel, filling the cavity of the same completely and adhering by chemical / physical adhesion to the head side 101 of the supporting layer 1 and to the free surface of the protection layers 2 facing the intermediate load-bearing layer 1 and which is provided along the protruding perimeter bands 102 of the bearing layers 2. The adhesion against the bands 102 of the load-bearing layers is such that a coupling is generated sealed against humidity or water that extends for each protective or covering layer 2 for the thickness of said layer and for the width of the peripheral strip 102 which forms the side wall of the peripheral groove of the panel which is filled by the rear flap 204 of the sealing edge 4. In this way a sealed coupling area is generated between the protective or covering elements 2 and sealing edge 4 which in the direction of the water penetration path has a very large dimension with reference to the thickness of said protective layers 2.

In the variant of Figure 6, instead of a single groove, the head side of the load-bearing layer 1 is shaped in such a way as to present two separate grooves, each of which extends at the level of the contact surface of one of the faces of the intermediate layer bearing with the respective protection layer 2 and along the area of the corresponding edge of the head side of said bearing layer 1. In particular, each of the two grooves is obtained thanks to a step recess made along the area of the corresponding head edge of the intermediate load-bearing layer, whereby the groove leaves free the face of the corresponding protective layer 2 facing the load-bearing layer 1 for a width corresponding to the depth of the groove and therefore of the step recess provided in the load-bearing layer 1. This surface forms one of the two side walls of the groove and is indicated by 102 having the same function as com and in the previous example. The opposite side surface of the groove is formed by the parallel surface 201 of the step recess, while the bottom of the groove is formed by the head side of the step recess 101â € ™.

In this case, the thickness of each of the two grooves is less than the overall thickness of the load-bearing layer 1 and is, for example, of the order of magnitude of a few millimeters or the thickness of the corresponding protective layer 2.

Similarly to the solution of the previous example, also in this variant, the sealing edge 4 has rear fins 104 which each penetrate into one of the two grooves, adhering by chemical-physical adhesion both to the material of the supporting layer 1 and to the material of the protective layers 2 and in this case along the leading edge of these and along the surface bands 102 which delimit the corresponding groove towards the outside.

In this case, a lower consumption of high-cost material is obtained and, moreover, the filling volume of the groove is also reduced, so that problems linked to injection imperfections are avoided. The advantages regarding sealing are the same as described in the previous example.

A further construction variant which is illustrated in figure 7 differs from that of figure 7 in that while in the example of figure 6, the head side of the remaining thick part of the bearing layer 1 provided between the two grooves extends flush with the head sides of the protective and / or covering layer (s) 2, in the example of Figure 7, the said remaining part of thickness of the load-bearing layer 2 extends beyond the head sides of the protective layers and / or coating 2. This implies that the quantity of material necessary for the realization of the sealing edge is further reduced, which in this case becomes formed by a wing of wood or similar coated along the head side and along the two faces parallel to the faces of the panel with a layer of plastic material which forms a sealing casing with a substantially inverted U section and which is connected by chemical-physical adhesion to the material of the stratum or carrier 1 and to the material of the protective layer or layers 2 with which it generates a watertight coupling.

This not only increases the contact surface between the material of the sealing edge 4 and the material of the protective layer (s) 2, but also the contact surface between the material of the sealing edge and the material of the carrier layer 1. This guarantees together a better watertight seal and a better anchoring of the sealing edge 4 to the load-bearing layer of the panel 1 so that said edge is fixed in a more resistant way to the panel.

Figure 8 illustrates yet another variant of the panel according to Figure 7, in this case the variant provides that in the extension or in the head extension 301 of the head side of the load-bearing layer 1 of wood or similar materials, one or more rows are provided of through holes 401 into which the sealing edge material penetrates forming mechanical anchoring through elements 304 with a function similar to fixing pins or nails but which are made in one piece with the remainder of the sealing edge 4. In this form therefore, in addition to the mechanical anchoring of the sealing edge due to the chemical / physical adhesion of the material of the sealing edge 4 to the panel and in particular to the load-bearing layer, said sealing edge has a mechanical coupling of shape with the layer carrier 1.

To understand the importance of this, it should be noted that since the coupling between the sealing edge 4 and the protective or covering layer or layers 2 is intended above all to provide a watertight seal against the infiltration of humidity or water, the same must be mechanically stressed to a minimum extent, since said function relates to the mechanical fixing or mechanical retention of the sealing edge 4 entrusted to the coupling of the latter to the load-bearing layer 1. Therefore in this embodiment the Increased mechanical resistance of the sealing edge-load-bearing layer coupling further relieves mechanical stresses from the coupling between said sealing edge and the protective layer or layers.

Fig. 9 illustrates a further embodiment variant, in which the groove has a bottom with an arched cross-section, so that the groove has a lying U-shaped cross section. This allows to better distribute the pressures of the sealing edge material 4 during the injection molding phase, preventing the strong pressures acting in a corner area from causing lifting of the protective layer 2 from the corresponding face of the bearing layer 1.

Figure 10 finally illustrates another variant in which the protective or covering layer or layers 2 are applied to the load-bearing layer 1 with the interposition of one or more further layers, such as layers of fibers, in the form of fabrics , matt, non-woven fabrics, or other types. In this case, the free protruding perimeter band of the protection layer indicated with 102 does not adhere directly to the material of the sealing edge 4, but with the interposition of the further layer or layers indicated with 5.

Although this alternative is illustrated with reference to the variant of Figure 9, it can be provided in combination with one or more any of the executive variants previously described. Furthermore, what has been said for the executive variant of Figure 10 also applies with reference to the executive variant of Figure 9.

Figure 11 illustrates a detail of a head side of a panel according to the embodiment of Figures 8 and possibly also 9 and / or 10. The sealing edge is illustrated with dashed lines. The figure clearly shows the extension 301 of the head side of the load-bearing layer 1 beyond the head side of the protection or covering layer 2. Furthermore, the row of through holes 401 in said extension 301 is visible. With reference to said holes, a further variant can provide instead of through holes a row of blind holes or notches on one or both opposite faces of the extension 301 of the head side of the bearing layer 1.

With reference to Figure 11, it also appears that the panel has a bevel or a recessed or missing area in correspondence with each of the two corner areas of the head side of the same and also for a certain length along the section of the longitudinal edges directly adjacent to said corner zones, whereby the sealing edge also extends along said corner zones and with portions 104 along said longitudinal edge portions. In correspondence with the corner areas, the sealing edge 4 completes the shape of the whole formed by the load-bearing layer 1 and by the protective layer (s) 2 so as to give the finished panel a rectangular shape, while along the recessed sections of the two longitudinal sides the sealing edge portions 104 end flush with said longitudinal sides of the panel consisting of the longitudinal sides of the load-bearing layer 1 and of the protective or covering layer (s) 2.

Advantageously, the set of load-bearing and protective or covering layers 2 and the longitudinal edge are shaped according to one or more of the alternatives described and illustrated with reference to figures 2 to 10 also along the rounded corner area and along the indentation of the initial section of the longitudinal sides.

Advantageously, the peripheral edge of the load-bearing layer 1 and coating layer or layers along the head side along the corner zone and along the initial lengths of the longitudinal sides has a rounded and curvilinear pattern in the corner zones and in the terminal areas of the portions falling along the longitudinal sides.

According to an improvement which can be provided in any combination with one or more of the previous executive variants, the panel can be provided with reinforced areas for attachment of disassembly tools, such as levers or crowbars, or the like. In this case, for example, when the panels are used to contain castings of floors or the like, they are disassembled by lifting or detaching with said tools which are inserted in correspondence with the head sides of said panels and that is to say the sealing edge.

In a first embodiment, in order to avoid damage to the panel in the sense that the mechanical action along the sealing edge determines a detachment of the same or a weakening of the coupling to the panel, in correspondence with the said attachment areas, the perimeter edge of the set of layers composed of the load-bearing layer 1 and the protective or covering layer (s) 2 has one or more recesses 6 distributed along its length and which are filled with the material of the sealing edge 4 which in said areas have a greater thickness in the direction of the distance between the outer edge of the sealing edge and the edge of the set of load-bearing layers 1 and protective layers 2. in the embodiment of figure 12, three recesses 6 are provided, one central on the side head and two lateral ones at the terminal ends of the recessed sections of the longitudinal sides of the whole formed by the load-bearing layer 1 and from the protective or covering layer (s) 2. It should be noted that the shape of the peripheral edge of the load-bearing layer and of the protective or covering layer (s) 2 continues without solution even along said recesses 6.

Figures 13 and 14 illustrate a variant in which the attachment points of the assembly tools indicated with 7 are made up of elements of plastic or other material incorporated by drowning and / or overmoulding or in any case embedded or embedded in the material of the sealing edge. 4.

In this embodiment the said attachment points 7 consist of elements such as blocks or the like which have an open cavity at one of the sides and in particular at the head side of the sealing edge 4. This allows for better and greater engagement safety the end of the lever or other similar tool avoiding, however, exerting a force directly on the sealing edge and avoiding that the attachment end of the tool against the panel can cause damage, for example in the event of slipping or accidental disengagement. As indicated by the central element 7 in figure 13 which is illustrated with a broken line, it is possible to provide one or more of said elements 7 in different points of the peripheral edge of the sealing edge 4.

With reference to the shape of the peripheral edge of the set of load-bearing layers 1 and protective or covering layers 2 which have a bevel in the corner area and a recess along the initial sections adjacent to said corner area of the longitudinal sides , as per the embodiments of figure 1 and figures 11 and 12, the function of this construction is to protect the corner areas which are the most sensitive to damage.

According to an improvement illustrated in the variants of Figures 15 to 18, the panel according to one or more of the embodiments illustrated above has a protective covering also along the said longitudinal sides. This coating has the purpose of protecting said longitudinal sides mainly from mechanical damage and is made in such a way as to allow any humidity that may have penetrated into the layers of wood to transpire from the longitudinal sides.

As can be seen from the figures, along each longitudinal side and in correspondence with the edges of the panel, the same is formed by protective edges 8 of plastic material, in particular of the same plastic material of which the edges of the transverse sides of the panel are made.

With reference to Figure 16, said protective edges 8 consist of a plastic filling of a step recess 108 provided along each corner between the longitudinal side and one of the two faces of the panel. The said step recess 108 is filled by the protective edge 8 so as to complete the cross section of the panel in correspondence with the said longitudinal sides. Each protection edge extends with one side flush with the corresponding longitudinal side of the panel and with the other side flush with the corresponding face of the panel.

Therefore, as shown in Figure 16, at each corner of the two longitudinal sides of the panel, the protective edges 8 extend for a certain depth in the direction of the thickness and for a certain depth in the direction of the width of the panel. The overall thickness of the protective edges is less than the overall thickness of the panel and therefore a median strip of wood is left uncovered along each longitudinal side.

In particular, the protective edges 8 are made by injection overmoulding of the longitudinal sides of the panel. This procedure can be carried out simultaneously with the realization of the edges of plastic material 4 along the transversal sides of the panel.

When the panel has an external sealing and / or protection layer 2 on one or both faces, the corresponding step 108 extends, in the direction of the thickness of the panel, also for the thickness of the sealing and protection layer 2 itself, so that the protective edge 8 of plastic material which forms the corresponding edge of the panel also covers the leading edge of the sealing and / or protection layer 2 adhering to the same by means of chemical-physical adhesion and fluid-tight.

The portion 208 of the bearing layer 1 projects outwards with respect to the sealing and protection layers and forms one side of the step at the corner.

As also illustrated in Figures 17 and 18, in order to have a better anchoring of the protective edges 8, the step recess 108 has on the side oriented towards the thickness of the panel a groove or groove which extends below the corresponding layer. of sealing and / or protection 2, the said groove being delimited on one side by the face 102 of the sealing and / or protection layer 2 which faces the load-bearing layer of the panel, so that the protection edge 8 also extends for a certain extent in said groove directly below a longitudinal peripheral band 102 of the sealing and / or protective layer 2 of the corresponding face of the panel.

With reference to figure 18, similarly to the embodiments already described above for the edges on the transversal head sides of the panel, also for the longitudinal sides said groove in the bottom or raised side of the step recess, i.e. in the side in the direction of the thickness of the panel, it can have a bottom side with an arched or rounded cross section.

In the embodiment of Figure 2 in which the load-bearing layer 1 consists of three layers of material 10A, 10B, 10C, of which two outermost layers 10A and 10B each consist of a second layer of material formed by at least one sheet of wood, while between them there is an intermediate layer 10C which is made up of a first layer of material formed by a plurality of strips, the said three layers being coupled together in a superimposed position on top of each other by means of gluing, the step recesses 108 along the edges of the longitudinal sides of the panel extend, in the direction of the thickness of the panel, for a depth at least equal to the thickness of said outermost layers 1A, 1B formed by one or more sheets of wood.

In Figure 17 the depth of the step recesses 108 is greater than the thickness of the layers 1A and 1B, while in Figure 18 said depth is substantially identical to the thickness of the layers 10A and 10B of the supporting layer 1 of the panel.

Thanks to this realization, the protective edges 8 of the longitudinal sides of the panel not only allow the transpiration of any humidity that may have penetrated the panel, as they leave free a part of the thickness of the longitudinal sides in which the wood of the load-bearing layer is uncovered and therefore directly exposed to the environment, but also seal the longitudinal sides of the wood sheets of the two outermost layers 10A and 10B, whose fibers extend transversely to the longitudinal direction and therefore are exposed in a favorable way to the moisture absorption. Therefore, as a third advantage obtained at the same time as the effective protection and transpiration ability of the panel, the sealing of the longitudinal sides of the layers which have fibers oriented transversely to said sides is also obtained.

Claims (2)

AMENDED CLAIMS 1. Panel for the construction of containment walls of formwork for concrete casting, in particular for containment formwork for the construction of concrete slabs or the like, which panel is made up of at least one load-bearing layer of wood which is It is externally coated at least partially with one or more layers of sealing and / or protection against humidity and / or water, the load-bearing layer being formed in turn by at least two layers, of which at least a first layer is made up of a plurality of strips having a predetermined length, which strips are made with the fibers of the wood oriented in the longitudinal direction of the strips themselves and which strips are glued to each other so as to form the said first layer in which they are arranged with the longitudinal axes oriented in a direction substantially parallel to each other, being the head sides of the load-bearing layer and of the panel oriented transversely to the direction of orientation of the wood fibers of the strips and / or to the longitudinal extension of the strips themselves, while the longitudinal lateral edges of the load-bearing layer and therefore of the panel are oriented parallel to the direction of surrounding of the wood fibers of the strips and / or to the extension length of the strips themselves, characterized by the fact that at least the second layer of wood that forms the load-bearing layer is made up of a sheet of wood, the fibers of which are joined in a transverse direction to the longitudinal extension of the panel or strips and / or in a direction transverse to the direction of orientation of the fibers of the strips being the two layers coupled together by gluing and being at least part of a head side of the panel oriented in a direction transverse to the direction of the fibers of the wood of the strips forming the first layer consisting of a sealing edge that is plastic, and overlaps the side of the load-bearing layer and / or of the sealing and / or protection layer (s) along at least said part of said head side and is fixed to said head side of the panel by chemical / physical adhesion and sealing it towards the outside. in which the load-bearing layer is made up of three layers of material, of which two layers of material each consist of a second layer of material formed by at least one sheet of wood, while between them there is an intermediate layer which is made up by a first layer of material formed by a plurality of strips, since the said three layers are coupled together in a superimposed position on top of each other by gluing, in which the or the sheets of wood which form the or the second layer of material of the carrier layer consist of a so-called veneer, wherein the panel has a protective coating along said longitudinal sides which forms or overlaps at least a part of the surface of said longitudinal sides, in which along said longitudinal sides the panel has a step-like recess at each corner between the longitudinal side and one of the two faces of the panel, which step-like recess is filled so as to complete the cross-section of the panel in correspondence of said longitudinal sides with a filling of plastic material which extends with one side flush with the corresponding longitudinal side of the panel and with the other side flush with the corresponding face of the panel / thus forming a longitudinal protective edge along each edge longitudinal panel / being the overall dimension of the protective edges at the two longitudinal edges of each longitudinal side of the panel, in the direction of the panel thickness, less than the overall thickness of the panel. 2. Panel according to one or more of the preceding claims, characterized in that the load-bearing layer is made up of three layers of material, of which two first layers of material each consisting of a plurality of strips and which form the outermost layers of material and a second layer of material which is interposed between said two first layers of material and which three Btratì are coupled together in a position superimposed on each other by gluing. 43. Panel according to one or more of the preceding claims 1 aâ € ”le 2, characterized in that the sheet of wood which forms the second layer or layers of material of the load-bearing layer is made of a hard wood. -54. Panel according to one or more of the preceding claims, characterized in that the wood sheet forming the second layer or layers of material of the carrier layer has a thickness lower than that of the first layer of material of the carrier layer, i.e. lower than the thickness of the strips which form said first layer of material. 6J5. Panel according to one or more of the preceding claims, characterized in that the second layer or layers of material of the load-bearing layer have a thickness of between 1 and 4mm. 3- (6. Panel according to one or more of the preceding claims, characterized in that the second layer or layers of material consist of at least two sheets of wood which are glued together in a relative position such that they have a crossed orientation between them of wood fibers. -97. Panel according to one or more of the preceding claims, characterized in that the load-bearing layer is covered on one or both faces with a layer of sealing and protection material, a groove or groove being provided, at least along a part of the sides of the panel along which the sealing edge is provided, the groove problem extends directly below the face of the protective layer (s) adhering to the load-bearing layer of the panel and which groove is delimited at least on one side by said face of the corresponding protective layer, while the sealing edge also extends inside said groove adhering by chemical / physical adhesion also to the bottom and to the side walls of the groove. Panel according to claim 97, characterized in that the groove extends for the entire thickness of the load-bearing layer and is bounded on both sides by the two opposite protective layers adhering to the two opposite faces of the load-bearing layer, the head side being of the load-bearing layer recessed with respect to the top sides of the two protection layers. Ï ‹_9. Panel according to claims 9 - 7 or 198, characterized by the fact that the groove has a thickness corresponding to a part of the thickness of the load-bearing layer and is laterally delimited on one side by the corresponding protective layer and on the other side by the parallel surface to the protection layer it gives a step recess which is made along the corner area of the side of the load-bearing layer which is directly underneath the protection layer, while the bottom of said groove consists of the step of said recess at step in the carrier layer. H IP. Panel according to one or more of claims Sâ € ”7 to Ï‹ 9, characterized in that the sealing edge has a filling extension of said groove and adheres by chemical-physical adhesion to the walls of the groove formed by the material of the load-bearing layer and of the protection layer. H ll. Panel according to one or more of the preceding claims, characterized in that the load-bearing layer is covered with a protective layer on each of the two opposite faces, then a groove of the aforesaid type having a partial thickness with respect to the overall thickness of the layer is provided bearing directly under each of the two protective layers and along the sides in correspondence with which the sealing edge is provided, the sealing edge being provided with filling extensions of each of said two grooves l (piles of extensions adhere by means of chemical / physical adhesion to the materials of the boundary walls of the grooves. 1412. Panel according to one or more of the preceding claims, characterized in that the protective layer or layers are made of plastic material and that the sealing edge adheres tightly against the head side of the said protective layer or layers and to the side of the of said protective layers which constitutes the side wall of the corresponding groove. ì3⁄413. Panel according to one or more of the preceding claims, characterized in that the sealing edge is made by injection molding on the corresponding side or sides of the assembly formed by the load-bearing layer or by the protective and / or covering layer or layers. 1- & 14. Panel according to one or more of the preceding claims, characterized in that the panel has a load-bearing layer interposed between two protection layers which adhere respectively to one face of the load-bearing layer, and the load-bearing layer is provided with a fin which is central with reference to the overall thickness of said load-bearing layer and which has a thickness less than the overall thickness of the load-bearing layer, which flap protrudes beyond the corresponding perimeter side of the protective layer or layers and which flap is incorporated into the sealing edge which covers it on the sides parallel to the faces of the panel and on the head side, completing the thickness of the panel until it reaches the overall thickness of the protection layers and the load-bearing layer. Ir? 15. Panel according to one or more of the preceding claims, characterized in that it has a groove or groove directly under each of the protection layers, which grooves or grooves are constituted by perimeter step recesses of the load-bearing layer, the said fin is constituted by a peripheral extension of the portion of the supporting layer comprised between the two stepped recesses, whereby the surfaces of said fin which are parallel to the faces of the panel extend flush with the corresponding surfaces of the stepped recesses which form said grooves or grooves. -3r & 16. Panel according to one or more of the preceding claims, characterized in that it has mechanical coupling means between the sealing edge and the material of the protective layer, which means are constituted by complementary interlocking means between the material of the sealing edge and the material of the protective layer. support. 3⁄4 £ 17. Panel according to the claim, characterized in that in said fins and preferably in the surfaces parallel to the faces of the panel there are holes or openings which are blind or passing through the thickness of the said fins, while the sealing edge penetrates into or through the same with projections or bridges of material which connect the two layers of material of said edge which cover the two faces of said fins which are parallel to the faces of the panel. -2- & 18. Panel according to one or more of the preceding claims, characterized in that between the protective layer (s) and the load-bearing layer there is provided a layer of fibers which layer of fibers may possibly also extend inside the corresponding groove or groove, in order to wherein the material of the sealing edge adheres to the protective layer indirectly with the interposition between the same material of the sealing edge and the protective layer of said layer of fibers. 3⁄4 19. Panel according to one or more of the preceding claims, characterized in that the sealing edge has reinforced inserts for attachment of tools for lifting or disassembling the panels, such as levers or crowbars or the like. £ -2-20. Panel according to claim -2-119, characterized in that inserts of rigid material, possibly provided with windows and recesses for engaging said lifting tools, are incorporated in the sealing edge. 2121. Panel according to claim 42 15, characterized in that said attachment inserts consist of areas of greater thickness of the sealing edge with reference to the thickness in a direction parallel to the faces of the panel. 2422. Panel according to one or more of the preceding claims, characterized in that the sealing edges are provided only along the head sides of the panel oriented transversely to the wood fibers of the load-bearing layer for at least part or for the entire thickness of the panel and / or for at least part or for the entire surface of the top layers of the panel. 2423. Panel according to one or more of the preceding claims, characterized in that the load-bearing wood layer has recessed corner areas which are filled with plastic inserts with a shape such as to complete the perimeter shape of the panel with an ideal shape provided for the same in the absence of said re-entrant areas. 2424. Panel according to claim 2220, characterized in that the groove or grooves under the protection layer or layers, is the possible fin of the protection layer, with or without through holes also extend along said beveled corner areas and along the initial recessed portion of the longitudinal sides of the panel directly adjacent to said corner areas. 2- ^ 25. Panel according to one or more of the preceding claims, characterized by the fact that as hard wood it is possible to precede Maple, Alder, Birch, Hickory, Hornbeam or white beech, Chestnut, Page, Ash, Walnut, Plane, Poplar, Cherry wood, Willow, Oak, Linden, Elm and also tropical woods such as Kauri pine, Iroko, Red pine. Rosewood, Brazilian Rosewood, Ebony, African Mahogany, Mansonia, Balsa, Nyatoh, Afrormosia, Meranti, Teak, White Frakà ̈, Ayous. 3-6-26. Second panel 2-3 one or more of the preceding claims, characterized in that for a certain depth in the direction of the thickness and for a certain depth in the direction of the width of the panel, the longitudinal edges of the same are formed by a protective border of plastic material. 3ÃŒ27. Panel according to one or more of the preceding claims â € "2-8â €" aâ € "3-6, characterized by the fact that the said step recess is filled with plastic material by injection molding, or the plastic edge in correspondence of the longitudinal edges of the panel, is made by injection molding. 3628. Panel according to one or more of the preceding claims â € "2-8â €" aâ € "34, characterized in that it has an external sealing and / or protection layer on one or both faces, while the corresponding step recess is extends, in the direction of the thickness of the panel, also for the thickness of the corresponding sealing and / or protection layer itself, so that the protective edge of plastic material that forms the corresponding edge of the panel also covers the leading edge of the sealing layer and / or protection. 3429. Panel according to one or more of the preceding claimsâ € "38â €" aâ € "3-3, characterized in that the step recess has on the side oriented towards the thickness of the panel, a groove or groove that extends below the corresponding sealing and / or protection layer, the said groove or groove being delimited on one side by the face of the sealing and / or protection layer facing the load-bearing layer of the panel, so that the protective edge also extends for a certain measure in said groove directly below a longitudinal peripheral band of the sealing and / or protective layer of the corresponding face of the panel. 3330. Panel according to one or more of the preceding claimsâ € "2-8â €" aâ € "34, characterized by the fact that the load-bearing layer is made up of three layers of material, of which two outermost layers each consist of a second layer of material formed by at least one sheet of wood, while an intermediate layer is interposed between them which is constituted by a first layer of material formed by a plurality of strips, since the said three layers are coupled together in a superimposed position on each other. other mediaulte gluing, while the step indentations along the edges of the longitudinal sides extend in the direction of the thickness of the panel for a depth at least equal to the thickness of said outermost layers formed by one or more sheets of wood.