FR3086883A1 - DEVICE FOR REINFORCING THE STRUCTURE OF A SLIDING BOARD - Google Patents

Abstract

The invention relates to a device (1) for reinforcing the structure of a gliding board comprising a stack (3) of layers of plant fibers. The stack (3) comprises, alternately along the width, a layer (5) whose fibers are in the plane formed by the axes x and z and oriented at an angle of (+) 45 ° relative to the direction (x ) the length of the stack; and a layer (6) the fibers of which are in the plane formed by the axes x and z and oriented at an angle of (-) 45 ° relative to the direction (x) of the length of the stack; each layer (5; 6) having a thickness in the width of said stack along the axis (y) of between 5 mm and 25 mm, preferably between 11 mm and 19 mm. The invention also relates to a method of manufacturing said device and a gliding board comprising said device.

Description

Device to reinforce the structure of a gHsse board

Technical Field [0001] The present invention relates to a device for reinforcing the structure of a gliding board, a gliding board comprising said device and a method for manufacturing said device.

Technical state of the art Gliding boards are known which comprise a core based on vegetable fibers, for example wood, the board also comprising a rigid metallic or composite layer bonded to the top and to the bottom of the board. . The wooden core is generally composed of several strips glued to each other.

Wood is a fibrous material which has anisotropic mechanical properties, that is to say different properties depending on the direction of the stress compared to the direction of the wood fiber. The strength and stiffness are maximum in the direction of the fibers, and minimum perpendicular to the fibers.

Gliding boards are known having a wood fiber core, the fibers being oriented along the length of the board, we speak of orientation at 0 °. In this orientation, the wood fiber gives good rigidity and optimal bending strength. In addition, 0 ° fiber boards are easily machinable and easy to handle.

However, in a sandwich structure as described above where the wood core is reinforced on both sides, the core mainly undergoes shear stress. Cores with fibers oriented at 0 ° or 90 ° do not provide adequate strength for shear stresses. So the existing gliding boards

BCOMP-7-FR including a wood fiber core does not provide satisfactory shear stress properties.

Brief Summary of the Invention An object of the present invention is to provide a device which is free or which minimizes the limitations of known devices. In particular, one of the aims of the present invention is to provide a device which has resistance to shear stresses.

According to the invention, these aims are achieved in particular by means of a device for reinforcing the structure of a gliding board, the device comprising:

- A stack of layers of plant fibers, said stack comprising a length, a width, and a thickness, the length having a direction (x) oriented along the longitudinal axis of the gliding board when the device is integrated into a board of gliding, the width having a direction (y) oriented perpendicular to said length and in the plane of the gliding board; the thickness having a direction (z) oriented perpendicular to said length and said width, the stack comprising, along the width in a direction (y) of said stack; alternately

- a layer whose fibers are in the plane formed by the x and z axes and oriented at an angle between (+) 4 T 'and (+) 49 ^e , preferably between (+) 44 ° and (+) 46 °, preferably by (+) 45 ° relative to the direction (x) of the length of the stack ,; and

- a layer whose fibers are in the plane formed by the x and z axes and oriented at an angle between (-) 41 ° and (-) 49 °,

BCOMP-7-FR preferably between (-) 44 ° and (-) 46 °, preferably from (-) 45 ° relative to the direction (x) of the length of the stack ,;

each layer having a thickness in the width of said stack along the axis (y) of between 5 mm and 25 mm, preferably between 11 mm and 19 mm.

This solution has the particular advantage over the prior art of providing a device having improved resistance to shear stresses.

In the solutions of the prior art with fibers oriented at 90 ° or 0 °, it is necessary to use layers of high density plant fibers, that is to say greater than 250 kg / m ³ to promote resistance to shear stresses. Advantageously, in the solution according to the invention, it is possible to use woods of low density, for example, a density of between 80 and 240 kg / m ³ , preferably 140-180 kg / m ³ . Advantageously, the density is substantially identical, that is to say homogeneous, so that the mechanical shear properties are homogeneous in the stack.

Advantageously, the properties of the stack are particularly satisfactory for a thickness greater than 10 mm and less than 25 mm, particularly between 11 mm and 19 mm. Indeed, the properties of resistance to shear stresses require fine alternation of the layers at +/- 45 °, with a layer thickness of less than 19 mm because each layer at + 45 ° must interact with a layer at -45 ° to be efficient. If the spacing between the alternating layers is too large, a large part of each layer no longer interacts with the next layer, reducing the effectiveness of the reinforcement. However, if the thickness of the layers is too small, less than 11 mm, the loss of material to obtain each layer becomes proportionally too great and the product loses all economic and ecological attractiveness. Manipulation of layers

BCOMP-7-FR with a thickness of less than 11mm also makes the manufacture of the product more delicate and complicated.

In one embodiment, the stack comprises

- at least two layers of vegetable fibers, the fibers of which are oriented along the axis (x) of the length of the stack or at an angle of 0 ° + / · 4 °, called external 0 ° layers, the layers with External 0 ° being placed on either side of the layers at +/- 45 ° so as to frame said layers at +/- 45 °; and / or at least two layers of plant fibers, the fibers of which are oriented along the axis (x) of the length of the stack or at an angle of 0 ° +/- 4 °, called internal 0 ° layers, each layer at internal 0 ° being placed between at least two layers at +/- 45 °.

Stacks comprising fibers at 7+ 45 ° have rigidity and low intrinsic resistance in bending, which makes handling and machining difficult. The presence of internal and / or external layers at 0 ° makes it possible to strengthen the resistance to bending stresses. The internal and / or external layers at 0 ° improve the core cohesion for the machining of the thickness profile necessary for the manufacture of a gliding board. They also facilitate the machining of the lateral shape of the gliding board. The presence of these layers at 0 ° also makes it easier to pre-glue the edges of the gliding board.

The external 0 ° layers have a lateral reinforcement function of the stack. The layers at 0 ° internally reinforce the internal structure of the stack. These reinforcements at 0 ° reinforce the flexural strength of the core. They facilitate the machining of the thickness profile. These internal layers also provide better anchoring to the screws of the bindings subsequently fixed to the gliding board. Preferably, these layers at 0 ° have a substantially identical density. These internal or external reinforcements at 0 ° are for example made up of layers of fibers of density greater than

BCOMP-7-FR 45 ° fiber layers, for example a density between 200800kg / m3, preferably 250-650kg / m3 for 0 ° layers.

According to one embodiment, the layers at 0 ° and the layers at 45 ° have a different thickness. For example, the external reinforcements at 0 ° can be between 20-35mm thick. It is advantageous to use a layer 20-35 mm thick compared to several thin layers bonded together. This solution is also more economical.

According to one embodiment, the vegetable fiber is chosen from wood, in particular from balsa, poplar, paulownia, spruce, pachaco, ash, maple, beech, birch, bamboo, pine, fir, okoumé, sengon (Paraseriantes fakataria) preferably balsa for layers at +/- 45 °.

In one embodiment, said layers at external 0 ° represent along the axis (y) between 10% and 60% of the width of the stack; and / or said internal 0 ° layers represent along the axis (y) between 10% and 60% of the width of the stack. These proportions offer in particular an interesting compromise between weight and properties of the stack, in particular reinforcement of the flexural strength or ease of manufacture or use.

According to one embodiment, the device further comprises terminal reinforcements at 0 ° at the distal ends along the axis the length (x) of the stack, said terminal reinforcements comprising plant fibers oriented along the axis ( x) in the length of the stack, preferably, said end reinforcements preferably covering the entire width of the stack along the axis (y) and representing along the x axis of the length of the board 10 to 40% of the length. The terminal reinforcements facilitate the machining of the profile and the periphery of the ends of the core, which are often machined very thin.

BCOMP-7-FR In one embodiment, the stack further comprises at least one layer of polymer, said polymer preferably being a polymer foam, for example a PET, PVC, PU, PMI, SAN or a honeycomb-type honeycomb structure made of aramid, Nomex, cellulose, PC, PP. Said layer of polymer can be interposed between two layers of fibers at +/- 45 as an inner layer. In this case, a low density polymer between 50-150 kg / m3 is preferably used to reduce the overall weight of the stack.

Alternatively, said polymer layer can be positioned on either side of the stack of layers at +/- 45 ° as an outer layer. In this case, an external foam of density 150-500 kg / m3 is preferably used to facilitate the machining of the core.

According to one embodiment, the stack has:

- a length between 1000mm and 2400mm, preferably between 1200mm and 2000mm, preferably between 1350mm and 1900mm; and or

- a width between 60mm and 400mm, preferably between 80mm and 320mm, preferably between 100mm and 150mm; and or

- a thickness between 5mm and 20mm, preferably between

10mm and 15mm, preferably between 11mm and 15mm.

According to one embodiment, the proportion of said layers of vegetable fibers at +/- 45 ° represents between 40% and 100% relative to the number of total layers of the stack.

In one embodiment, the device is a reinforcing board for gliding board.

BCOMP-7-FR Another object of the invention is to provide an improved method for the manufacture of a device for reinforcing the structure of a gliding board, in particular a more efficient method, for example to minimize the falls or loss of material.

According to the invention, these aims are achieved in particular by means of a method of manufacturing a device for reinforcing the structure of a gliding board, for example a reinforcing board, the method comprising:

i) form a basic block which has, in a space defined by three axes x, y, z orthogonal to each other, a length oriented along the x axis, a width oriented along the y axis and a thickness oriented along the z axis, the basic block comprising a stack along the z axis formed by an alternation of layers of plant fibers oriented along the y axis or at an angle of 90 ° +/- 4 ° called layers at 90 °, and layers of vegetable fibers oriented along x axis or at an angle of 0 ° +/- 4 ° called layers at 0 °, each layer having a thickness (e) of between 5 mm and 25 mm, preferably between 11 mm and 19 mm, said layer basic block comprising a first layer of vegetable fibers on which is superimposed at least one additional layer of vegetable fibers;

ü) cutting an initial block in the base block by cutting said base block according to two cutting planes,

at. a first cutting plane transverse to said base block, so as to cut each layer according to its thickness, said first plane passing through the z axis and forming an angle between (+) 41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the x and y axes of the block;

BCOMP-7-FR

b. a second cutting plane transverse to said base block, so as to cut each layer according to its thickness, said second plane passing through the z axis and forming an angle between (+) 41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the x and y axes of the block and parallel to the first cutting plane;

il!) cut at least one device to reinforce the structure of a gliding board, for example a reinforcing board, in the initial block, said device being cut along a third plane 10 parallel to the first cutting plane;

The layers of the base block may consist of several base boards assembled together for example by gluing, finger jointing, finger jointing, beveling or butt bonding. Glue can be deposited between each layer to ensure the cohesion of the block. The thickness of the base block corresponds to the width of the future reinforcement board. The method thus makes it possible to adjust the number of layers of the base block as a function of the width of the desired reinforcement board. The process offers great flexibility to the manufacturer, who can produce reinforcement boards of the desired width on request.

Advantageously, once the base block has reached the desired thickness, it can be pressed before cutting the initial block.

According to one embodiment, the basic block is a rectangular parallelepiped so that the cutting of the initial block in the basic block in the first plane and in the second plane generates a first fall, the initial block and a second fall, the method comprising:

providing the first fall and the second fall generated by the cutting of the initial block in the base block;

BCOMP-7-FR form a second initial block by assembling the first fall with the second fall to form a parallelepiped in which the face of the first fall along the first cutting plane is parallel to the face of the second falling along the second plane cutting;

- cut at least one device to reinforce the structure of a gliding board, for example a board, in the second initial block, said device being cut along a fourth plane parallel to the face of the first fall along the first cutting plane .

In the latter embodiment, the base block is a rectangular parallelepiped, in other words a block. The cutting of the initial block generates two falls which are complementary and which can be assembled to form a second initial block. Thus, this embodiment makes it possible to recycle the scraps from the first base block to form a second base block in which it is possible to cut at least one board. The process is gaining in efficiency because it is possible to make more boards from the same basic block.

In one embodiment, the method comprises:

- form a third initial block by assembling the first initial block and the second initial block, so that in the third initial block,

at. the face of the first fall from the cut along the first cut plane and

b. the face of the second fall from the cut according to the second cut plane

BCOMP-7-FR

vs. are each aligned with one of the faces of the first initial block from the first cut or the second cut;

- repeat the previous step using “n” basic blocks until the third initiai block reaches a predetermined length;

cutting a final block of desired length L along the longitudinal axis x in the third initial block, said block being cut along a fifth plane perpendicular to the first cutting plane and a plane parallel to the fifth plane and spaced by a distance equal to the length L;

- cut at least one device to reinforce the structure of a gliding board, for example a board of length L, in the final block according to a sixth plane parallel to the first cutting plane.

In the latter embodiment, the user can modulate the length of the third initial block until it reaches the desired length. To do this, the user uses "n" basic blocks to generate "n" first initial block and "n" second initial block. Then, the first initial block and the second initial block are assembled to form a third initial block. I. In other words, the third initial block includes a “first initial block + second initial block” pattern repeated n times.

If the basic block "A" generates a first initial block "2" and falls "1 and 3", the falls "1 and 3" being assembled to form a second initial block, then the third initial block comprises a pattern "3,1,2" which is repeated in the third initial block. This pattern "3,1,2" can be repeated indefinitely, adding basic blocks.

BCOMP-7-FR In this embodiment, the method allows the user to manufacture boards of length L determined from a single initial block. This initial block can be lengthened by adding at one end of the block the pattern "3,1,2" coming from successive basic blocks, while blocks of length L are cut from this initial block at the other end of the block. A process thus almost continuous generating no fall is obtained.

According to one embodiment, the method comprises:

- Layers of plant fibers oriented along the length L of the final block are assembled on either side along the Z axis of the final block; and or

- Blocks of vegetable fibers oriented along the length L of the final block are assembled at each end of the final block along the length L;

Cut at least one device to reinforce the structure of a gliding board, for example a board of length L, in the final block along a plane parallel to the first cutting plane;

In this embodiment, the method allows cutting boards in a final block already comprising lateral or terminal reinforcements. In other words, the composition of the stack is determined upstream which makes it possible to improve the efficiency of the process for producing identical reinforcement boards on a large scale.

The invention also relates to a sliding board comprising a device according to the invention. For example, the gliding board is chosen from skis, snowboard, wakeboard, kiteboard.

In the present invention, the terms "layer at + 45 °" denotes a layer of plant fibers oriented at an angle between (+)

BCOMP-7-FR

41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the direction (x) of the length of the stack.

In the present invention, the terms "layer at - 45 °" denotes a layer of plant fibers oriented at an angle between (-) 41 ° and (+ - 49 °, preferably between (-) 44 ° and (-) 46 °, preferably (-) 45 ° relative to the direction (x) of the length of the stack.

In the present invention, the terms "layer at external or internal 0 °" means a layer of plant fibers whose fibers are oriented along the axis (x) of the length of the stack or at an angle of 0 ° +/- 4 °.

In the present invention, the terms "layer at 90 °" denotes a layer of plant fibers, the fibers of which are oriented perpendicular to the axis (x) of the length of the stack or at an angle of 90 ° + / - 4 °.

In the present invention, the layer of plant fibers may comprise only plant fibers, for example wood fibers. Alternatively, the layer of plant fibers can be a composite comprising plant fibers and another compound, for example a polymer. In this case, the proportion of vegetable fiber is for example the majority in the composite. For example, the plant layer may include flax fibers and a polymer: in this case, the plant layer is formed by a composite of plant fibers.

Brief description of the figures Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

BC0MP-7-FR Figures 1 to 4 illustrate a device according to a first embodiment;

FIG. 5 illustrates a method according to a first embodiment;

Figure 6 illustrates a method according to a second embodiment;

Figure 7 illustrates a method according to a third embodiment;

Figure 8 illustrates a method according to a fourth embodiment;

Example (s) of embodiment of the invention Figures 1 to 8 show embodiments of the invention, but the invention is not limited to these embodiments.

Figures 1 to 4 show a device 1 which is a reinforcing board 2 for skiing. Plate 2 comprises a stack 3 comprising 15 layers of vegetable fibers, in this example balsa layers 4 having a density of 160 kg / m ³ The stack 3 comprises a length L along the axis x, a width I along the y axis, and a thickness e along the z axis.

The stack 3 comprises an alternation of layer 5 at + 45 ° and 20 of layer 6 at -45 °, the angle of +/- 45 ° being defined relative to the x axis.

The layers of balsa 5,6 have a thickness of 11 mm.

BCOMP-7-FR In FIG. 2, the board 2 also comprises external lateral reinforcements 7 25 mm thick. The side reinforcements 7 are made of Sengon which has a density of 300 kg / m3. In this embodiment, the lateral reinforcements 7 extend over the entire length L of the stack 3.

In Figure 3, the plate 2 further comprises terminal reinforcements in 8 of 150mm in length. The terminal reinforcements 8 are made of Sengon which has a density of 300 kg / m3. In this embodiment, the terminal reinforcements 8 extend over the width I of the stack 3.

4 shows the board comprising both the lateral reinforcements 7 and terminal reinforcements 8. The board as shown in Figure 4 is thus ready to be machined according to a thickness profile and a contour and integrated in a ski.

Figures 5a, b show a manufacturing method according to the invention according to a first embodiment. Figure 5a is a perspective view to facilitate understanding of the invention. Figure 5b is a top view.

FIG. 5a represents a base block 100 for forming reinforcement boards comprising a stack 103 of balsa layers 104. The base block 100 comprises a base layer 107 on which five additional layers 108 are superimposed. The block base 100 is shown from base layer 107, i.e. base layer 107 and additional layers 108 are vertical.

The base block 100 is formed by alternating layers 109 at 0 ° and layers 110 at 90 °, the orientation of the fibers is represented by the cross X in FIG. 5a.

BCOMP-7-FR The thickness of the base block 100, that is to say the addition of the thicknesses of the base layers 107 and additional layers 108 along the z axis will determine the width of the support board to be made.

FIG. 5b represents an initial block 111 which has been cut from the base block according to two cutting planes shown in FIG. 5a, a first plane A and a second plane B. The cutting along plane A also generates a first fall 112; the cut along plane B generates a second fall 113.

The planes A and B are parallel to each other. The planes A and B pass through the z axis and form an angle of 45 ° with respect to the x and y axes.

In Figure 5b, the initial block 111 is shown so that the planes A and B are parallel to the x axis; in other words, a 45 ° rotation is applied around the z axis to the initial block 111 between FIG. 5a and FIG. 5b, the reference frame xyz remaining fixed.

The cutting of the initial block 111 in the base block 100 according to planes A and B with an angle of 45 ° makes it possible to obtain, after rotation of the block of 45 °, an initial block with alternating layers 105 to +45 ° and layer 106 at -45 °.

Reinforcement boards 102 are then cut from the initial block 111 according to a third cutting plane C. The cutting plane C is parallel to the plane A (and thus to the plane B).

Figure 6 shows a method according to a second embodiment. FIG. 6 represents the first fall 112 and the second fall 113 assembled in a second initial block 114. In the second initial block 114, the face of the first fall 115 along the cutting plane A is parallel to the face of second fall 116 according to the cutting plane B. The first fall 112 is for example glued to the second fall 113.

BCOMP-7-FR Then, reinforcement boards 102 can be cut from the second initial block 111 according to a fourth cutting plane D, said plane D being parallel to said faces 116 and 115.

Thus, according to the method shown in Figure 6, it is possible to reuse the falls 112 and 113 from the formation of the first initial block 111.

Figure 7 shows a third embodiment of the method. In this embodiment, a final block 117 is assembled using several base blocks 100. The base blocks 100 are cut along planes A and B as illustrated in FIG. 5a to generate initial blocks 111, first falls 112 and second falls 113.

In the final block 117:

the face 115 of the first fall along the plane A is aligned with the face 119 of the initial block according to the second cutting plane B;

- the face 116 of the second fall along the plane B is aligned with the face 118 of the initial block along the first cutting plane A;

The number of base blocks 100 used to assemble the final block 117 is determined as a function of the length L desired for the final block, this length corresponding to the length L along the x axis of future reinforcement boards which will be cut from the final block 117. The length L is adjusted by cutting the final block 117 according to a fifth cutting plane E, said plane E being perpendicular to the first cutting plane A (and thus to plane B).

Then reinforcing boards 102 are cut from the final block 117 according to a sixth cutting plane F parallel to the first cutting plane A (and thus B).

BCOMP-7-FR [0071] FIGS. 8 a, b represent an exploded view and a general view of the final block of FIG. 7, said block 117 further comprising:

- blocks (or panels) of plant fibers 120 to form lateral reinforcements (reference 7 in FIG. 4); and

- blocks of vegetable fibers 121 to form terminal reinforcements (reference 8 in FIG. 4).

In this embodiment, the vegetable fiber panels 120 are made of Sengon and the vegetable fiber blocks 121 are made of Sengon.

Advantageously, the reinforcement boards which will be cut out 10 in the final block comprising the plant panels 120 and the plant blocks 121 will include side reinforcements 7 and terminal reinforcements 8 as shown in FIG. 4, said reinforcements 7.8 being derived respectively from said vegetable fiber panels 120 and vegetable fiber block 121. For this, the block is cut according to a seventh cutting plane G parallel to the first cutting plane A (and thus to B).

BCOMP-7-FR

Reference numbers used in the figures

Device according to a first embodiment

Reinforcement board for ski

Stacking

Balsa layer

Layer at + 45 °

-45 ° layer

Lateral reinforcements

Terminal reinforcements

Basic block

Reinforcement board

Stacking

Balsa layer

Layer at + 45 °

-45 ° layer

Basecoat

Additional layer

0 ° layer

90 ° layer

Initial block

First fall

Second fall

Second initial block

Face of the first fall according to plan A

Face of the second fall according to plan B

Final block

Face of the initial block according to the first cutting plane

Face of the initial block according to the second cutting plane Plant fiber panels

Block of vegetable fibers

First cutting plane

Second cutting plane

BC0MP-7-FR

C Third cutting plane

D Fourth cutting plane

E Fifth cutting plane

F Sixth cutting plane

G Seventh cutting plane

Claims (16)

Claims 1. Device (1) for reinforcing the structure of a gliding board, the device comprising: - A stack (3) of layers of plant fibers (4), said stack (3) comprising a length, a width and a thickness, the length having a direction (x) oriented along the longitudinal axis of the board slides when the device (1) is integrated in a sliding board, the width having a direction (y) oriented perpendicular to said length and in the plane of the sliding board; the thickness having a direction (z) oriented perpendicular to said length and to said width, - The stack (3) comprising, along the width in a direction (y) of said stack; alternately o a layer (5; 105) whose fibers are in the plane formed by the x and z axes and oriented at an angle between (+) 41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the direction (x) of the length of the stack (3); and o a layer (6; 106) whose fibers are in the plane formed by the x and z axes and oriented at an angle between (·) 41 ° and (-) 49 °, preferably between (-) 44 ° and (-) 46 °, BCOMP-7-FR preferably (-) 45 ° relative to the direction (x) of the length of the stack (3); - Each layer (5; 6; 105; 106) having a thickness in the width of said stack (3) along the axis (y) of between 5 mm and 25 mm, preferably between 11 mm and 19 mm. 2. Device (1) according to claim 1, the stack (3) comprising: - at least two layers of plant fibers whose fibers are oriented along the axis (x) of the length of the board or at an angle of 0 ° +/- 4 °, called external 0 ° layers (7), 0 ° outer layers (7) being placed on either side of the +/- 45 ° layers so as to frame said layers at +/- 45 °; and or - at least two layers of vegetable fibers, the fibers of which are oriented along the axis (x) of the length of the board or at an angle of 0 ° +/- 4 °, called internal 0 ° layers (7), each layer at internal 0 ° being placed between at least two layers at +/- 45 °. 3. Device (1) according to the preceding claim, in which: - said external 0 ° layers representing between 10% and 60% of the width of the stack along the axis (y); and or - said internal 0 ° layers representing between 10% and 60% of the width of the stack along the axis (y). 4. Device (1) according to one of claims 1 to 3, wherein the device (1) further comprises 0 ° terminal reinforcements (8) at the distal ends along the axis the length (x) of the stack (3), said end reinforcements (8) comprising plant fibers oriented along the axis (x) in the length of the stack (3), preferably, said reinforcements BCOMP-7-FR terminals (8) preferably covering the entire width of the stack (3) along the axis (y) and representing along the x axis of the length of the device 10 to 40% of the length 5. Device (1) according to one of claims 1 to 4, wherein the stack (3) further comprises at least one layer of polymer, said polymer preferably being a polymeric foam, for example a PET foam, PVC , PU, PMI, SAN 6. Device (1) according to one of claims 1 to 5, in which the stack (3) has: - a length between 1000 mm and 2400mm, preferably between 1200 mm and 2000 mm, preferably between 1350 mm and 1900 mm; and or - A width between 60 mm and 400mm, preferably between 80 mm and 320 mm, preferably between 100 mm and 150mm; and or - A thickness between 5 mm and 20mm, preferably between 10 mm and 15mm, preferably between 11 mm and 15 mm. 7. Device (1) according to one of claims 1 to 6, in which the proportion of said layers of vegetable fibers at +/- 45 ° represents between 40% and 100% relative to the number of total layers of the stack ( 3). 8. Device (1) according to one of claims 1 to 7, wherein the layers of vegetable fibers at +/- 45 ° (5; 6; 105; 106) have a substantially identical density, preferably a density between 80 and 240kg / m3, preferably 140-180 kg / m3. BCOMP-7-FR 9. Device (1) according to one of claims 2 to 8, wherein the layers of vegetable fibers at 0 ° (7; 8) have a substantially identical density, preferably a density between 200-800kg / m3, of preferably 250-650kg / m3 for 0 ^e layers. 10. Device (1) according to one of claims 1 to 9, wherein the vegetable fiber is chosen from wood, in particular, from balsa, poplar, paulownia, spruce, pachaco, ash, l maple, beech, birch, bamboo, pine, fir, okoumé, sengon (Paraseriantes fakatana, preferably balsa for layers at +/- 45 °. 11. Device (1) according to one of claims 1 to 10, wherein the device (1) is a reinforcement board for gliding board (2). 12. Method of manufacturing a device for reinforcing the structure of a gliding board, for example a reinforcing board (2), the method comprising: i) forming a basic block (100) which has, in a space defined by three axes x, y, z orthogonal to each other, a length oriented along the x axis, a width oriented along the y axis and a thickness oriented along the z axis, the base block (100) comprising a stack (103) along the z axis formed by an alternating layer (104) of plant fibers oriented along the y axis or at an angle of 90 ° +/- 4 ° named layers at 90 ° (110) and layer of vegetable fibers oriented along axis x or at an angle of 0 ° +/- 4 ° called layers at 0 ° (109), each layer (104) having a thickness ( e) between 5 mm and 25 mm, preferably between 11 mm and 19 mm, said base block (100) comprising a first layer of plant fibers (107) on which is superimposed at least one additional layer (108) of fibers vegetable; il) cutting an initial block (111) in the base block (100) by cutting said base block (100) according to two cutting planes. BCOMP-7-FR at. a first cutting plane (A) transverse to said base block (100), so as to cut each layer (104) according to its thickness, said first plane (A) passing through the z axis and forming an angle between (+ ) 41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the x and y axes of the block (100); b. a second cutting plane (B) transverse to said base block (100), so as to cut each layer (104) according to its thickness, said second plane (B) passing through the z axis and forming an angle between (+ ) 41 ° and (+) 49 °, preferably between (+) 44 ° and (+) 46 °, preferably (+) 45 ° relative to the x and y axes of the block and parallel to the cutting plane (A); ill) cutting at least one device (1) to reinforce the structure of a gliding board, for example a reinforcing board (102), in the initial block (111), said device (1) being cut along a third plane (C) parallel to the first cutting plane (A); 13. Method according to the preceding claim, wherein the base block (100) is a rectangular parallelepiped so that the cutting of the initial block (111) in the base block (100) in the foreground (A) and according to the second plane (B) generates a first fall (112), the initial block (111) and a second fall (113), the method comprising: - providing the first drop (112) and the second drop (113) generated by cutting the initial block (111) in the base block (100); - Form a second initial block (114) by assembling the first fall (112) with the second fall (113) to form a parallelepiped in which the face of the first fall along the first cutting plane (115) is parallel to the face of the second fall along the second cutting plane (116); BCOMP-7-FR - cutting at least one device (1) to reinforce the structure of a gliding board, for example a reinforcing board, in the second initial block (114), said device being cut along a fourth plane (D) parallel to the face of the first fall along the first cutting plane (A). 14. Method according to the preceding claim, in which - Form a third initial block by assembling the first initial block (111) and the second initial block (114), so that in the third initial block, o the face of the first fall from the cut in the foreground of cutting (118) and o the face of the second drop resulting from cutting according to the second cutting plane (119) o are each aligned with one of the faces (115; 116) of the first initial block coming from the first cutting or the second cut; repeat the previous step using "n" basic blocks until the third initial block reaches a predetermined length; - cutting a final block (117) of desired length L along the longitudinal axis in the third initial block, said block being cut along a fifth plane perpendicular to the first cutting plane and a plane parallel to the fifth plane and spaced by a distance equal to the length L; BC0MP-7-FR Cut at least one device to reinforce the structure of a gliding board, for example a reinforcement board (102) of length L, in the final block (117) according to a sixth plane (F) parallel to the first cutting plane (A). 15. Method according to the preceding claim, in which - Layers of plant fibers (120) oriented along the length L of the final block are assembled on either side along the axis Z of the final block (117); and or - Vegetable fiber blocks (121) oriented along the length L of the 10 final block are assembled at each end of the final block (117) along the length L; - Cut at least one device to reinforce the structure of a gliding board, for example a board of length L, in the final block according to a seventh plane (G) parallel to the first plane of 15 cutout (A); 16. Gliding board comprising a device (1) according to one of claims 1 to 11.