The present invention relates to the general technical field of attachment systems for planks or boards made of wood for example on a support structure in order to create floors, floor coverings, or walls, and in particular outdoor decks.
The present invention relates to an attachment of wooden boards on a support structure composed for example of wooden beams such as joists and strips
The fastening of boards by screws is already known. Such fastening assumes pre-drilling holes through the boards in a very precise pattern in order to accurately define the positions of the screws. Screw sockets must also be created to accommodate the screw heads. All the screws must then be tightened one after the other.
Such a fastening method requires the proper tools to be available at jobsites and takes a substantial amount of assembly time, particularly for the layout and screwing steps. Moreover, such a method produces board flooring with visible screw heads, which mar the appearance of said flooring.
Elements for fastening at least one modular covering board to a support structure are also known, comprising:
Document DE 20 2005 002 204 U1 describes for example a fastening element designed to engage positively in a recess provided in a board. The engagement is made possible because of the elastic deformation properties of the fastening element, which has adequate flexibility. The fastening element is made of synthetic material or aluminum. Since the use of a fastening element has some flexibility, permitting engagement of the snap-in type, a mechanical link is often generated which could be altered by stresses on the board. Also, the use of an aluminum fastening element is an expensive technical solution whose elastic deformation properties are moreover not always satisfactory.
Outdoor decking is often subjected to substantial variations in heat and humidity over the year, which can cause deformations in wood boards. Hence, these stresses must be taken into account to enhance the lifetime of the deck. Exotic, very hard woods are often used for this purpose.
However, the boards may undergo contractions as large as 5 mm. Such contractions impose substantial stresses on the fastening systems and contribute to weakening the link between the boards and the support structure.
Also, exposure of the upper faces of the boards to the sun causes uneven drying in the thickness of the boards. This phenomenon causes deformation of the boards called “curling.” The “curling” phenomenon causes the boards to assume a substantially concave or convex shape in cross section. One or the other of these deformations generates stresses that are substantially orthogonal to the support face of the boards, so that the fastening elements are weakened or even broken. These deformations can also cause the fastening elements to work their way out of their recesses in the board. With time, a less reliable join between the support structure and the boards always occurs.
One goal of the present invention is to create a fastening element used for mounting boards in the form of a covering, of the outdoor decking type, enabling the boards to undergo size variations and deformations linked to changes in temperature and humidity without altering the reliability of the mechanical join between the boards and the support structure.
Another goal of the present invention is to create a covering made of wooden boards, for example an outdoor deck, with a fastening able to effect simple and rapid mounting without resorting to specific mounting and assembly tools.
Another goal of the present invention is to optimize the performance of such a fastening element while limiting its manufacturing cost.
According to the invention, the projecting part of the fastening element has a full tongue provided with stiffening means with the fastening face, whose free end is formed with the front ends of the tenons meeting at an acute angle, the tenons being separated from the full tongue in the vicinity of their rear ends opposite the ends forming the acute angle, said rear ends being elastically deformable in order to come close to the full tongue when the board is engaged on the projecting part.
Because of its optimized shape the fastening element has sufficient rigidity to prevent bending or twisting of its middle part comprised of the full tongue associated with the stiffening means.
The shape and dimensions of the tenons also enable the elastic deformation properties in the engagement direction of a board, as well as optimum rigidity in the reverse direction, to be conferred on the fastening element, thus preventing the board from pulling back.
The fastening element is made for example in a single piece by injection or molding of a synthetic material.
According to one embodiment, the fastening face constituting the support face of the board has longitudinally, on either side of each projecting part, a substantially concave shape, obtained by adjusting the thickness of the base. A fastening element is thus obtained whose board support face has a shape that as exactly as possible matches the shapes of the boards that curl. When curling generates a substantially concave shape, it is the middle part of the board, viewed in cross section, and located between two projecting parts, that rests on the concave face of the fastening element. When curling brings about a substantially convex shape, viewed in cross section, it is the lateral ends of the board located beyond two adjacent projecting parts, directed essentially downward, that match the beginning of a concave shape, being oriented substantially toward said fastening face.
In either case, the vertical forces acting on the fastening elements are substantially reduced, particularly on the projecting parts engaged in the recesses of the board. This prevents premature wear of the fastening and does not affect the irreversible engagement of the board with the fastening elements.
The fastening element according to the invention has, according to one preferred embodiment, means for adjusting its lengthwise positioning on the support structure, said adjusting means being stressable once the fastening element has been joined to the support structure.
The base of the fastening element has for this purpose local oblong areas with a smaller thickness, each designed to be traversed by a fastening screw of said fastening element. The thickness is chosen such as to allow displacement in the lengthwise direction of the fastening element under the effect of a lengthwise stress exerted on the projecting parts. This displacement is made possible because of the creep of material between the base and the fastening screw or screws. The oblong areas of smaller thickness are, for example, the bottoms of beveled cavities that are inserted between the conical heads of the fastening screws and the support structure. Contraction of the boards will thus cause creep of the material of smaller thickness located at the bottoms of the beveled cavities and traversed by the fastening screws so as to absorb said contraction by lengthwise displacement of the fastening element relative to the support structure. The fastening element according to the invention then has the advantage that a board can deform in various directions without generating harmful stresses on the projecting parts.
Also, it is preferable to make the engagement of the boards on the fastening elements irreversible. For this purpose, it is desirable to increase the stiffening of the projecting parts and allow them to deflect elastically for snapping engagement in the recesses of the boards. The elastic properties are then no longer useful in an irreversible mounting configuration. The greater the rigidity of the projecting parts, the greater the irreversibility.
The use of means for stiffening the projecting parts thus improves the irreversibility of the mounting and reduces the risk that the boards will pull back once mounted on their support structure. However, the quest for optimal rigidity increases the risk that the projecting parts will break if forces are generated in the lengthwise direction by lateral contraction of the boards. The possibility of absorbing such a lateral contraction of the boards by sliding the fastening elements in the lengthwise direction increases the service life of the fastening elements on the one hand and remarkably improves the reliability of the irreversibility of the mounting of said boards on their support structure on the other hand.
According to one embodiment, the projecting part has a full tongue with harpoon-shaped tenons, said tenons being elastically deformable in a lateral direction in order to move toward the full tongue when the board engages. Engagement of the board on the fastening elements is thus done by a snap-in type of operation.
According to one embodiment, the stiffening means are comprised of a widening of the lower part of the full tongue. The lower part also constitutes the link between the base and the projecting part.
According to one embodiment, the stiffening means are comprised of reinforcements, orthogonal relative to the fastening face, and integral with the full tongue at the lengthwise or lateral ends of the latter. The sizes of the reinforcements are chosen to allow the projecting part to engage in the corresponding recess. Such stiffening means are very easy to make, particularly when produced in one piece with the fastening elements, for example by plastic casting or injection. The reinforcements can also serve as supporting elements for the board engaged on the projecting part.
According to another embodiment of the invention, the projecting part has two adjacent, parallel tabs, each having a tenon, so that the two tabs are urged together by elastic deformation when the tabs engage in the recess. The adjacent tabs of a given pair are for example connected with each other in the vicinity of the base with at least one lengthwise stiffening edge.
According to one embodiment, each fastening element has several projecting parts and the base has, at its lengthwise ends, a dovetail shape for assembly with an adjacent fastening element. The dimensions of the fastening elements as well as the number of projecting parts on each fastening element can be chosen according to the dimensions of the boards.
According to one embodiment, the fastening element has a millimetric scale, for example 1 to 592 mm.
The assembly according to the invention also allows a fixed gap between two adjacent boards to be provided. This leads to good absorption of the dimensional variations in the wooden boards due to changes in humidity and temperature. Such a gap also enhances ventilation between the boards and the joists, and the risk of water pooling leading to wood decay is thus greatly reduced.
Another non-negligible advantage is achieved by the fact that the natural movements of the wood have no effect on the mechanical connection with the fastening elements. One useful feature emerges from the engagement or snapping in of the fastening elements in the recesses, thus producing a rigid, stable mechanical link without thereby placing stress on parts or areas of the wood experiencing this natural movement, or on the fastening elements.
The goals of the invention are also achieved with the aid of a mounting and assembling assembly of a covering including boards made of wood for example to make a deck or floor and fastening elements such as those referred to above, the boards each having at least one recess in the shape of a lengthwise cavity whose shape matches that of the projecting parts of the fastening elements.
The mounting assembly also includes a support structure of the joist or strip type supporting the boards, with the fastening elements effecting a mounting and fastening interface between the support structure and the boards.
Another advantage of the mounting assembly according to the invention resides in the reduction of the wood's natural tendency to deform under the action of the sun, by machining cavities and grooves on the lower faces of the boards. These cavities and grooves at least partly absorb the natural strains inherent in wood that often cause twisting, cracking, and warping. The grooves constitute recesses provided in the boards.
Once assembled, the mounting assembly constitutes for example a deck, a balcony, a ceiling, or a vertical wall.
The goals of the invention are also achieved with the aid of a method for mounting modular covering boards on a support structure, consisting of:
This gives the advantage of joining the boards to the support structure by a single snapping operation orthogonal to the supporting surface of the support structure. Moreover, this operation is irreversible because, once they are attached to the fastening elements, the boards can no longer be removed by pulling them in a direction opposite to the snap-in engagement direction.
It is also possible to mount the fastening elements directly on the joists in the shop and bring them to the jobsite equipped with the fastening elements. No particular tools are necessary for mounting the boards on the support structure. Thus they are quickly assembled, reducing material and labor costs.
For maintenance or replacement of deteriorating boards, the boards are completely disengaged by pulling on them in a lengthwise direction which is the same as the lengthwise axis of the boards. This pulling causes the cresses to slide on the corresponding fastening elements. Thus, the fastening elements are not damaged. Moreover, it is possible to remove one or more boards for repair work on a deck for example and them snap them back in without damaging either the boards or the fastening elements.
Because of the invention, attachment means that are invisible at the upper faces of the covering boards are obtained.
The mounting method according to the invention also enables boards of significant length to be used, for example between 2 and 3 meters, particular with the use of Brazilian Ipe boards known for their decay resistance and superior quality, also for their straightness.
Other features and advantages will also emerge from the detailed description provided below with reference to the attached drawings of non-limitative examples, wherein:
and
The fastening element (3) according to the invention and shown in
The locking tabs (9) have tenons (10) that are oriented obliquely away from the locking tab (9) in the direction of the base. The tenons (10) of two adjacent locking tabs (9) extend in opposite directions and obliquely toward the base, in the lengthwise direction of the fastening element (3). The tenons (10) are advantageously shaped to prevent any board (1) from pulling back once the locking tabs (9) are completely engaged in the corresponding recess (4) of board (1).
According to one embodiment, each fastening element (3) has several pairs of locking tabs (9) distributed along its lengthwise extension. Each fastening element (3) has for example six or eight pairs of locking tabs (9).
It is also possible to provide, on each fastening element (3), a millimetric scale, for example from 1 to 592 mm, facilitating the cutting of this fastening element (3) according to the desired length.
The base of the fastening element (3) also has holes (11) for passage of fastening screws (12) between the locking tabs (9) of a given pair. This enables the fastening elements (3) to be screwed to the support structure (2).
A shape of the dovetail type (13, 14) can be provided at the lengthwise ends of each fastening element (3) for assembly with the adjacent fastening element (3). The ends (13, 14) are for example beveled to facilitate their interlocking. This provides control over the regularity of the gaps between the projecting parts (8) of two sequential fastening elements (3). It is thus possible to fully control the regularity of the gaps (15) between the boards (1). This gap (15) is for example between 3 and 5 mm. The gap (15) not only enables water spilling onto the upper faces (5a) of the boards (1) to be drained but also the dimensional variations in said boards to be at least partly absorbed.
Full control of the regularity of the gaps (15) also improves the visual appearance of the covering effected by a succession of boards (1).
The projecting parts (8) also have stiffening means. The locking tabs (9) of a given pair are thus connected to each other in the vicinity of the base with a stiffener (16) that constitutes a stiffening means. The stiffening edge (16) confers on the locking tabs (9) increased resistance to deforming stresses in the recess (4) that in general act on the projecting parts (8). The stiffened locking tabs (9) are less subject to deformation, rendering the fastening of the board (1) more reliable by ensuring irreversibility of the mounting of the boards (1) on the support structure (2). This increased stiffness also affords better resistance to any momentary strains on the wood caused by changes in humidity and/or temperature.
The tenons (10) have sloping front faces (17) that engage in the recess (4) to urge together the sloping front faces (17) of the locking tabs (9) by elastic deformation.
Each tenon (10) also has a holding face (18) essentially parallel to the upper face (7) that comes into position opposite an inside edge (19) of recess (4) once board (1) is completely engaged and the locking tabs (9) have returned to their initial resting positions. For this purpose, the recess (4) has the shape of a lengthwise cavity ending at the inside face (5) of board (1), whose side walls each have a groove (20) in order to present an essentially T-shaped cross section. Reference may be made for example to
The inside edges (19) cannot be released from the stop constituted by the corresponding holding faces (18), thus providing an irreversible assembly of the boards (1).
One example of the assembly of boards (1) on a support structure (2) by means of the fastening elements (3) according to the invention is shown for example in
Three variants of the fastening elements (3) according to the invention are shown in
In the embodiment shown in
The adjusting means comprise areas of lesser local thickness (22), oblong in shape and designed to be traversed each by a fastening screw (12). The locally less-thick areas (22) each corresponding for example to a bottom of an oblong beveled recess (23), provided in the fastening face (7) of the fastening element (3). This lesser thickness is chosen so as to allow slight movement in the lengthwise direction of the fastening element (3) under the effect of a lengthwise stress applied to the projecting parts (8). This movement is made possible because of the creep property of the material of which the locally less-thick areas (22) are made between the base and the fastening screw (12). The fastening elements (3) can then move relative to the fastening screws (12) passing through them.
In this way it is possible to absorb the stresses generated by contraction of the boards (1) for example in direction C1 or direction C2 shown in
Between two adjacent projecting parts (8) each engaged in a separate board that contracts, a slight extension is observed of the base connecting said projecting parts (8). The fastening element (3) according to the invention thus has a base of which a first portion (3a) undergoes a deformation and of which a second portion (3b) undergoes an extension when the boards (1) contract. Reference may be made for example to
In the example of
In the embodiment shown in
The second portion (3b) of the base also has breaks (3c). These enable the fastening element (3) to be broken off more easily, without tools, to adjust its length to the number of boards (1) used for a floor covering or a deck.
The fastening face (7) constituting the support face of the board (1) has longitudinally, on either side of each projecting part (8), a substantially concave shape (7a) obtained by gradual, continuous adjustment of the thickness of the base of the fastening element (3). Reference may be made for example to
When board (1) is not deformed (see
Furthermore, when a deformation occurs as indicated in
The fastening element (3) according to the invention thus substantially reduces the stresses linked to a curling phenomenon that would damage the integrity of the fastening over time.
Advantageously, the base of the fastening elements (3) has gaps (21) that in particular afford material savings in manufacture. The fastening elements (3) are made for example in a single piece by injection or casting of a synthetic material of the polypropylene, POM, or PA type.
The method according to the invention of assembling modular covering boards (1) on the support structure (2) thus consists of using the fastening elements (3) to attach the boards (1) to the support structure (2) and integrate said fastening elements (3) with said support structure (2).
According to another step in the method according to the invention, it is appropriate to position the boards (1) with their recess (4) facing the projecting parts (8) of the fastening elements (3).
Next, according to an additional step, it is appropriate to move the boards (1) in a single direction (E) (see
Assembly of boards (1) is thus achieved extremely simply with a minimum of assembly operations, with preparation being limited to machining the recesses (4) in each of the boards (1).
According to one implementation example of the method according to the invention, it is possible to adjust the positions of the boards (1) by sliding them in the lengthwise direction (A) of the recess or recesses (4) as shown for example in
The present invention also relates to an apparatus for mounting and assembling a covering from which, after assembly, a deck, balcony, floor, vertical wall, or ceiling can be made. It is thus particularly useful to employ the fastening elements (3) according to the invention for weather-boarding or siding operations.
Without departing from the framework of the present invention, the boards (1) can be made of a synthetic material of the composite wood type.
It is also possible, without departing from the framework of the present invention, to transpose the technical features of one embodiment of the fastening element (3) to another embodiment of said fastening element (3). Thus it is possible to provide on the fastening element (3) shown for example in
Number | Date | Country | Kind |
---|---|---|---|
0511299 | Nov 2005 | FR | national |
0602616 | Mar 2006 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FR2006/002489 | 11/7/2006 | WO | 00 | 8/20/2008 |