EP1693089B1 - Slide board - Google Patents

Description

Technical area

The invention relates to the field of manufacturing gliding boards, including boards gliding on snow. It relates more specifically to a new structure of gliding boards including a particular textile mechanical reinforcement.

Previous techniques

In general, boards gliding on snow, whether skis or snowboards, have a structure that includes mechanical reinforcements to strengthen its longitudinal rigidity.

Among the reinforcements employed, the fibrous structures, and in particular the fibrous sheets of reinforcements based on glass fibers impregnated with a thermosetting resin, are known. These reinforcements can be in different forms, but always include a set of son extending in the longitudinal direction of the board. These different son can be assembled by weaving, to form a substantially unidirectional reinforcement. It is also possible to associate a sheet of longitudinal son to a support layer, for example by sewing or gluing.

Furthermore, it is known that the gliding boards have a line of dimensions that can be more or less dug depending on the type of board, so that the width of the board changes, and generally increases, the central area of the board. board towards the ends.

Consequently, the fibrous reinforcing plies mentioned above, and integrated into the structures of these planks, also have a variable width. Such a reinforcement is thus obtained by cutting in a strip fabric complex to the geometry of the board. These cuts generate a number of disadvantages.

Indeed, during manufacture, the reinforcing fibrous web is manipulated to be arranged in a mold, in order to be associated with the rest of the structure of the board, either by molding with a pre-existing core or by in situ injection of polyurethane components. The areas of the fibrous reinforcing ply having the greatest width therefore comprise a number of short threads at the edges of the cut strip. These short son are relatively poorly maintained relative to the rest of the fibrous web, which therefore has the risk of fraying.

The threads that escape from the fibrous web are positioned abnormally during the molding of the board. They then cause irregularities in appearance or structural defects that may require the scrapping of the board.

Moreover, these relatively short son have only a very limited effect on the stiffness that is supposed to confer the reinforcement, because they extend over a very short length of the board. However, these same threads are impregnated with resin and therefore increase the weight of the reinforcement in the widest area of the board. However, a lightening boards gliding is sought, and the additional mass created by these son, without effect on the stiffness of the board, can be considered superfluous.

In addition, the fact that the reinforcing fibrous sheet is wider at the widest areas of the ski leads to an increase in the stiffness of the board in these areas. However, it has been found that this accentuated reinforcement may not be of particular interest, and unnecessarily increase the weight of the board.

Indeed, in the particular case of snowboarding, it is found that the most mechanically stressed areas, and therefore the most fragile, are those located directly in front of and behind the bindings, while the existing reinforcements to date confer a increased rigidity at the board at the birth of the spatulas, since it is in these areas that the board is the widest.

A problem that the invention proposes to solve is that of the optimization on the surface of the board of the stiffness conferred by the fibrous layers of reinforcements.

As a solution to this problem, it has been proposed to make reinforcements representing complex shapes.

Thus, the document FR 2 546 413 describes skis comprising reinforcements consisting of several elements juxtaposed, and made of different materials. Of course, it is understood that this construction is relatively complicated and requires delicate handling during manufacture.

Fibrous reinforcing plies with a complex shape have also been proposed in the document FR 2,855,427 , but they include a set of cuts that increases the problems of fraying mentioned above. The Applicant described in the document FR 2,699,827 reinforcements consisting of textile ribbons, the shape of which substantially follows the line of dimensions. This solution is not completely satisfactory insofar as the ribbons are superimposed in the central area of the ski, generating an extra thickness that can be seen on the upper face of the ski.

The object of the invention is therefore to provide a reinforcing structure that allows both to optimize the distribution of the additional stiffness imparted by the reinforcement, without increasing the handling constraints at the time of manufacture.

Presentation of the invention

The invention therefore relates to a board for gliding on snow. This board has a line of dimensions that widens from the central area of the board towards the ends of the board. This board comprises a structure which includes at least one reinforcing fibrous sheet, comprising threads in the longitudinal direction of the board.

According to the invention, the fibrous reinforcing ply is such that the number of threads per unit length of the fibrous reinforcing ply, measured in the transverse direction of the plank, varies from the narrowest zone of the plank to pointing to the point or points of maximum width of the board, that is to say the widest area or areas of the board.

In other words, the fibrous reinforcing ply used has a yarn density which is not constant, but instead evolves along the length of the plank.

In other words, the threads of the reinforcing fibrous web may be farther (or closer) to each other at certain levels of the plank, thus corresponding to areas where the density of longitudinal threads is less (or more significant).

In practice, it is possible to achieve the variation of this density in different ways, depending on the properties that it is desired to confer on the board.

Thus, in a first embodiment, the number of threads per unit length, measured in a transverse direction, can firstly increase from the central area, towards the fastener mounting areas, and then decrease further. beyond by heading towards the point or points of maximum width of the board. In other words, in this case, the density of the reinforcing threads is maximum in the vicinity of the fixation mounting areas, areas which are more mechanically stressed, and which therefore benefit from increased reinforcement.

In a second embodiment, the number of threads per unit length, measured in the transverse direction, may decrease with the widening of the dimension line.

In other words, the fibrous reinforcing ply employed has a yarn density which is greater at the level of the central zone of the plank, that is to say in the zone where the plank is the narrowest. The density of longitudinal threads of the fibrous reinforcement ply decreases, and is therefore lower in the widest area of the plank. Of the so, the fibrous reinforcement ply increases the stiffness of the plank at its widest area, but to a lesser extent than if the fibrous reinforcement ply was of constant density.

In other words, the fibers of the fibrous reinforcing ply are farther apart from each other at the widest level of the plank than they are at the central part of the plank, where it is generally the more narrow.

In practice, according to a first embodiment, the fibrous reinforcing ply may extend over the entire width of the plank, in the area where it is present. In other words, the fibrous reinforcing ply is stretched transversely to follow the dimension line so that the selvedges of the reinforcement are constituted by a single and continuous yarn, which eliminates any risk of fraying as mentioned above.

In this case, the number of threads per unit length, measured in the transverse direction, varies inversely proportional to the width of the board, since the reinforcement has a constant number of threads, but which are distributed over a widening width. with the width of the board.

In an alternative embodiment, the fibrous reinforcing ply may not extend transversely over the entire width of the plank. It then has selvedges that deviate slightly from the sidecut in certain areas of the board, while widening.

In practice, the characteristic reinforcing fibrous web may extend over almost the entire length of the board, typically from one line of contact to the other. It may also be present on only a portion of the length of the board, and for example in areas requiring mechanical reinforcement. It is also possible to combine several fibrous reinforcing plies having a variable density. These sheets can be superimposed, that is to say overlap in all or part, or be juxtaposed, ie arranged disjointly in various areas of the board.

In practice, the adjustment of the optimum density of the reinforcing threads can be improved and accentuated by making recesses inside the reinforcing fibrous sheet. These recesses can be made by cutting and removal of material inside the fibrous web, or else by the production of the fibrous web itself, in which some threads are sufficiently spaced to form these recesses by an absence of threads. enhancement.

In practice, different textile reinforcement structures can be used to produce boards according to the invention.

In a first variant embodiment, the reinforcing fiber sheet may comprise at least two superimposed layers, namely a first layer formed by a layer of wires extending in the longitudinal direction, and a second support layer, to which are secured reinforcing threads. In this case, the support layer may advantageously have a deformable structure in the transverse direction of the board to allow the stretching of the complex thus formed, and the decrease in the number of son per unit length in the characteristic areas.

In another variant embodiment, the reinforcing fibrous sheet may consist of a weave of a plurality of main yarns extending in the longitudinal direction of the board, with perpendicular yarns which advantageously have a stretching capacity. In this case, these stretchable son extend transversely to the board. They can be deformed to remove the main reinforcing wires, in areas that require it.

In practice, it is also possible to vary the properties of the reinforcement in the transverse direction of the latter. Indeed, it is possible to use reinforcing son which have properties, including nature or title, which are different over the width of the reinforcing ply.

Thus, by way of example, it is possible to use carbon, glass or aramid yarns which have different mechanical properties and which are arranged along the width of the reinforcement with a distribution which depends on the mechanical properties which the we want to give the board. Thus, for the realization of a snowboard snowboard, we can focus on the son of greater tenacity at the edge of the reinforcement, these areas being intended to be located near the edges, where the solicitations are more important.

It is also possible to use son with different titles, and equally distributed appropriately across the width of the board. Thus, the son whose title is higher can be, as for the previous example, at the edges of the reinforcement for gliding boards, or even at the central level, possibly with a transverse graduation of title elaborated according to the degree of reinforcement that one wishes to give to the board.

Brief description of the figures

• La figure 1 est une vue de dessus d'une planche conforme à l'invention, dans laquelle la nappe fibreuse caractéristique est montrée de manière apparente.
• Les figures 2 et 3 sont des vues de détail correspondant aux zones (II) et (III) de la figure 1.
• La figure 4 est une vue de dessus d'une variante de réalisation d'une planche conforme à l'invention, dans laquelle la nappe fibreuse de renfort est montrée apparente.
• La figure 5 est une vue de détail correspondant à la zone V de la figure 4.
• La figure 6 est une vue de dessus d'une nappe fibreuse de renfort réalisée conformément à une variante d'exécution.
• La figure 7 est une vue de dessus d'une nappe fibreuse réalisée conformément à une autre variante d'exécution.
• Les figures 8 et 9 sont des vues en coupe d'un nappe fibreuse de renfort réalisée selon une première forme d'exécution, montrées en deux zones distantes longitudinalement de la planche.
• Les figures 10 et 11 sont des vues en coupe, similaires aux figures 8 et 9, pour une autre variante de réalisation de la nappe fibreuse de renfort.
• La figure 12 est une vue en coupe d'une nappe fibreuse de renfort réalisée avec des fils de titres variables.

The manner of carrying out the invention as well as the advantages which result therefrom will emerge clearly from the description of the embodiments which follow, in support of the appended figures in which:

• The figure 1 is a top view of a board according to the invention, in which the characteristic fibrous sheet is shown visibly.
• The Figures 2 and 3 are detailed views corresponding to zones (II) and (III) of the figure 1 .
• The figure 4 is a top view of an alternative embodiment of a board according to the invention, wherein the reinforcing fibrous sheet is shown apparent.
• The figure 5 is a detail view corresponding to zone V of the figure 4 .
• The figure 6 is a top view of a fibrous reinforcing ply made according to a variant embodiment.
• The figure 7 is a top view of a fibrous web made according to another embodiment.
• The Figures 8 and 9 are cross-sectional views of a fibrous reinforcing ply made according to a first embodiment, shown in two zones spaced longitudinally from the plank.
• The Figures 10 and 11 are sectional views, similar to Figures 8 and 9 , for another variant embodiment of the reinforcing fibrous sheet.
• The figure 12 is a sectional view of a fibrous reinforcement web made with son of variable titles.

Way of realizing the invention

As illustrated by the plan on figure 1 , a gliding board (1) has a line of dimensions (2) corresponding to the lateral edges of the board, which is not rectilinear. Precisely, this line of dimensions (2) widens from the central zone (3) of the board towards the ends.

This dimension line widens to a point (4) of maximum width located at the front of the board. The dimension line also widens backward to a point of maximum width (5). In general, the ends of the board end with curved areas upwardly tapering to form a spatula (6).

On certain types of skis, the rear end (7) can also be curved to form a rear spatula, generally less raised.

The structure of the gliding board comprises as evoked a fibrous reinforcing ply formed by a textile complex (10), comprising most of its son (11) oriented in the longitudinal direction of the board. These yarns (11) are generally constituted by high-tenacity yarns, and especially glass, without, however, excluding materials with similar properties, such as carbon or aramid fibers, alone or in combination. These threads are generally formed by joined rovings.

According to the invention, the various son (11) ensuring the rigidity of the reinforcing fibrous web (10) are not strictly parallel, but instead deviate with the widening of the board. Thus, as illustrated in figure 2 the number of yarns per unit of width (d ₁ ) measured transversely to the board is less than the number of yarns in the same unit of width (d ₂ ), measured at the widest level of the board, as shown to the figure 3 .

The wires (11) illustrated in detail in the figure 2 are more assembled, and have relatively low centers (e ₁ ). Conversely, and as illustrated in figure 3 , the son (12) are more crushed, and have a spacing (e ₂ ) higher. By way of example, the reinforcements conventionally used for the manufacture of skis comprise a set of rovings from 600 to 2400 tex, distributed at the rate of 5 threads per centimeter, with therefore a spacing e ₁ between threads of the order of 2 mm at level of the skate zone.

In an exemplary embodiment of the invention, the number of threads per centimeter can be reduced to a value of 2 to 3 threads per centimeter at the widest area (4).

The density or the density of the fibrous reinforcing ply present inside the plank decreases towards the spatulas. It follows that the reinforcement imparted by the ply (10) is less in the widest zone of the plank, which is generally less mechanically constrained.

We thus obtain an overall lightening of the board without reducing its mechanical properties in terms of strength.

In the form illustrated in the figure 1 , the fibrous reinforcing ply (10) has a width which corresponds to that of the plank, and therefore follows the dimension line (2). The number of threads per centimeter is therefore directly inversely proportional to the width of the board, insofar as the number of threads of the fibrous sheet remains constant over its entire length.

In the variant embodiment illustrated in figure 4 the fibrous reinforcing ply (20) has a certain enlargement but does not strictly follow the dimension line (2). In this way, the yarns (21) of the fibrous web (20) remain parallel at the level of the slipper zone and in the zone directly in front of the slipper zone, while the plank begins to widen in this zone.

The threads (21) constituting the fibrous web subsequently deviate, according to the invention, to the widest area (4) of the board. The density of the reinforcement is set to remain the strongest at the level where the mechanical stresses undergone are the highest, and typically close to the front and rear of the fasteners.

According to another characteristic of the invention, it may be advantageous to eliminate certain parts of the fibrous reinforcing ply in the zones that do not require special reinforcement, so as to reduce the weight of the plank. This is the case for a snowboard, in the center of the board in the area between the bindings. This lightening can be obtained in different ways as illustrated in figure 6 .

Thus, it is possible to make a recess (26) by eliminating by punch cutting for example, a particular area of the reinforcing fibrous web (25). It is also possible to ensure a stretching of the reinforcement (25) such that consecutive son (27,28) are no longer joined, and define between them a zone (29) free of reinforcing son.

The embodiment variant illustrated in figure 7 corresponds to a reinforcement (70) whose son density has increases and decreases along the board. More precisely, at the level of the central zone of the board (71), the reinforcement (70) extends substantially over the entire width of the board.

Further, at the mounting mounting areas (72), the width of the reinforcement (70) tapers to a minimum. Then, beyond, and moving towards the widest areas (74,75) of the board, the reinforcement also widens.

By way of example, this variation makes it possible to modulate the density of the reinforcement significantly, typically going from a value close to 900 g / m ² at the level of the central zone (71) of the board, to increase up to at 1100 g / m ² at the attachment mounting areas, and finally decrease to a value close to 700 g / m ² in the widest area (74) of the board. Of course, these values are given by way of example, and they can be adapted according to the type of board and the desired rigidity.

In practice, different structures can be employed to achieve the characteristic effect of the invention.

Thus, as illustrated in figure 8 , the various longitudinal son (31) of the reinforcement (30) are associated with a support layer (32), typically formed by a mat or a web of synthetic fibers or glass. The longitudinal threads (31) are connected to this support layer (32) via a seam (33). The support layer (32) illustrated in figure 7 has a degree of stretchability that allows it to expand, as illustrated in figure 8 . The sewing thread (33) itself also has a stretchability, so as to follow the deformation of the support layer (32) itself irreversible.

In an embodiment variant illustrated in figure 10 , the reinforcement (40) is constituted by a roving weave (41) with a weft yarn (42) of very low titre, so as to generate a low embossing. This weft yarn (42) has a stretching ability, preferably irreversible, to allow the stretching of the reinforcement as shown in FIG. figure 11 . For example, on a snowboard snowboard, this stretching can reach a value close to 35%, passing the width of the sheet from a minimum value of 240 mm to a value of 320 mm in the zones les wider.

The figure 12 illustrates an alternative embodiment in which the son of the reinforcement (50) have different titles. Thus, the son (51) located in a central area have a lower title son (52) located at the edges of the reinforcement (50). Of course, the reverse arrangement can be used, with gradual variations compared to that illustrated in FIG. figure 12 or marked variations with a smaller number of different threads.

In practice, the realization of the characteristic reinforcements can be carried out also by using particular looms having adjustable combs. These adjustable combs, known per se, have distances between teeth that are variable, and can be programmed in real time depending on the progress of weaving the reinforcement. Different types of adjustable combs can be used, including combs having different segments orientable about an axis perpendicular to the fabric.

Other variants may be envisaged, although they have not been shown, for example by employing support structures of the gauze type, or even a weave employing weft yarns on which loops are made allowing the following the stretching of the fabric.

• ■ une adaptation de la densité du renfort fibreux à la répartition des contraintes mécaniques observées sur la planche ;
• ■ un allègement de la planche par l'élimination de zones de renfort de moindre intérêt ;
• ■ un état de surface régulier de la planche malgré la présence de renforts d'épaisseur non constante ;
• ■ une facilité de manipulation lors des différents renforts lors des étapes de fabrication.

It follows from the foregoing that the gliding boards according to the invention have many advantages among which:

• ■ an adaptation of the density of the fibrous reinforcement to the distribution of the mechanical stresses observed on the board;
• ■ lightening the board by eliminating reinforcement zones of lesser interest;
• ■ a regular surface condition of the board despite the presence of reinforcements of non-constant thickness;
• ■ ease of handling during different reinforcements during the manufacturing stages.

Claims (14)

1. A snow gliding board (1) having a sidecut (2) that widens from the middle area (3) of the board towards at least one of its ends to a point of maximum width (4) and of which the structure includes a reinforcing fibre mat (10) comprising yarns (11) that extend in the longitudinal direction of the board, characterised in that the number of yarns (11) per unit of length of the reinforcing fibre mat, measured across the board, varies from the middle area (3) towards the point of maximum width (4) of the board.
2. A gliding board as claimed in claim 1, characterised in that the number of yarns per unit of length reaches its maximum value in the vicinity of areas (72) where bindings are mounted.
3. A gliding board as claimed in claim 1, characterised in that the number of yarns per unit of length increases from the middle area (71) towards areas (72) where bindings are mounted and then diminishes beyond this point towards the point of maximum width (74) of the board.
4. A gliding board as claimed in claim 1, characterised in that the number of yarns per unit of length measured in the transverse direction reduces as the sidecut of the board widens.
5. A gliding board as claimed in claim 1, characterised in that the stiffener (10) extends over the entire width of the board.
6. A gliding board as claimed in claim 1, characterised in that the number of yarns measured over the entire length of the stiffener is constant over its entire length.
7. A gliding board as claimed in claim 1, characterised in that the reinforcing fibre mat extends over only part of the length of the board.
8. A gliding board as claimed in claim 1, characterised in that it comprises several reinforcing fibre mats placed one above the other or juxtaposed.
9. A gliding board as claimed in claim 1, characterised in that the stiffener (25) has openings (26, 29).
10. A gliding board as claimed in claim 1, characterised in that the openings (26) are made by cutting out and removing material.
11. A gliding board as claimed in claim 1, characterised in that the openings (29) are made by spreading apart the yarns (27, 28) that constitute the stiffener.
12. A gliding board as claimed in claim 1, characterised in that the stiffener (30) comprises at least two layers, namely a first layer formed by a mat of yarns (31) extending in the longitudinal direction of the board and a second support layer (32) having a structure capable of deformation in the transverse direction of the board.
13. A gliding board as claimed in claim 1, characterised in that the stiffener (40) comprises a plurality of yarns (41) extending in the longitudinal direction of the board woven with a plurality of perpendicular yarns (42) that have the ability to stretch.
14. A gliding board as claimed in claim 1, characterised in that the yarns (51, 52) of the reinforcing fibre mat (50) have different properties, especially in terms of their nature or size, over the width of said mat.

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