FR3058899A1 - SLIDING BOARD STRUCTURE ELEMENT - Google Patents

Abstract

Gliding board (1), including a structural element (20, 21) implanted in a raised end of the board, said element (20, 21) having a perforated structure and having through recesses (160), characterized in that at least a portion of the recesses (160) are defined between two elongate portions (151, 152) extending substantially perpendicular to the axis (15) of the board.

Description

Technical area

The invention relates to the field of sliding sports on snow or on water. It relates more particularly to a new board structure, incorporating an element integrated into the raised ends of the board, with a particular influence on the weight, the mechanical stiffness properties as well as the aesthetics of the board.

Previous techniques

Generally speaking, a gliding board is composed of the assembly of various layers of rigid reinforcements, spaced from the neutral fiber by a core. Thus, the core rests on a lower assembly, consisting of a gliding sole bordered by lateral edges, as well as one or more layers of reinforcements. Likewise, the core is covered by the upper assembly, which comprises one or more layers of reinforcements as well as an upper layer of decoration and protection. The core can consist of a preformed part associated with the upper and lower assemblies before molding which gives the final shape of the board. The core can also be made of a material injected during molding, to occupy the volume between the upper assembly and the lower assembly.

At the ends of the board, whether for a ski with the tip located at the front, or the heel located at the back, the board has a reduced thickness, so that the core is also less thick, and therefore much more fragile, or more difficult to handle. This is why it is common to use cores which do not extend to the end of the board, and to incorporate beyond the core a specific element, which is interposed between the lower assembly and the upper set. Reinforcement layers can be reduced or even interrupted in these extreme areas.

The Applicant has already described in documents FR 2 983 415 and FR 2 983 414, elements incorporated in the ends of the board, which are made from an injected material, and which are arranged in front and / or in back of the core during molding. Due to the material used, this element gives sufficient rigidity to the end of the board, which can be subjected to mechanical stresses, in particular impact with regard to the front end. In the solutions described in the aforementioned documents, the incorporated element has an openwork structure, on the one hand to reduce its weight and thus reduce the influence of the weight of the spatula in driving the board. On the other hand, the openwork nature of this incorporated element allows a certain transmission of light through the structure of the board at its end, with a visual aesthetic effect.

However, it has been found that these incorporated elements have a significant impact on the mechanical properties of the end of the board, and in particular its bending stiffness. Indeed, because of the shape of the recesses drilled through this incorporated element, which are regular circular or hexagonal, the mechanical properties of flexural rigidity are substantially similar in the longitudinal and transverse directions. However, because of the minimum thickness of this element, to facilitate handling, it can be seen that the rigidity in longitudinal bending of the board may be slightly excessive, while the rigidity in transverse bending can be considered as generally insufficient.

Statement of the invention

An objective of the invention is to provide a board structure whose bending stiffness at the ends is relatively reduced, while retaining a satisfactory transverse bending stiffness. Another objective of the invention is to limit the mass of the elements incorporated at the ends of the board, to limit the moment of inertia, and facilitate the handling of the board.

To do this, the Applicant has developed a sliding board which includes a structural element implanted in a raised end of the board, this element having an openwork structure and comprising through recesses.

In accordance with the invention, at least some of these recesses are defined between two elongated portions extending substantially perpendicular to the axis of the board.

In other words, the invention consists in giving the recesses a shape which is much wider in the transverse direction than in the longitudinal direction. These recesses are thus delimited by relatively thin portions, the dimension of which in the longitudinal direction is very much less than the dimension measured in the transverse direction.

In other words, the incorporated element or structural element comprises portions of material which act as transverse beams, thus with a relatively high transverse bending stiffness. On the other hand, the elongate portions being clearly separated in the longitudinal direction, the incorporated element therefore has a relatively reduced longitudinal bending stiffness, in addition to a lighter mass compared to known solutions. This incorporated element is therefore an anisotropic part from the point of view of its rigidity.

In practice, the slender portions can adopt different geometries. It can thus be rectilinear portions, the width, that is to say the smallest dimension, measured in the longitudinal direction, is very small, typically at least 10 times less than the length, measured transversely. between the two points of the rest of the element on which are connected this slender portion.

The elongate portions can also have a wavy shape, either with a curved shape, or with a shape composed of a series of successive segments, two consecutive segments forming a non-zero angle between them.

In practice, the positioning of the connection points of the elongated portions with the rest of the incorporated element can be adapted as a function of the desired mechanical properties. Thus, the elongated portions can extend between two points located at the same longitudinal level, or even at slightly offset levels, in the direction of the length of the board. It is also possible to mix these different embodiments, with certain portions which extend between two points located at the

-4 same longitudinal level, and other portions with anchor points offset in one direction and / or the other.

In a first embodiment, the elongated portions can extend between two points located on the peripheral zone of the structural element. In other words, the incorporated structural element has a peripheral portion which forms its periphery, and on which the elongated portions are attached, which therefore extend over almost the entire width of the structural element.

In another embodiment, the structural element may include two solid zones, oriented substantially longitudinally, and between which elongate portions extend. In other words, the characteristic elongated portions do not extend over the entire width of the incorporated structural element, but only at intermediate levels in width, defined by the solid zones oriented substantially parallel to the axis of the board. These additional portions influence by slightly increasing the longitudinal bending stiffness of the board, and it is possible to act on this stiffness by providing that these solid areas have areas of lesser width at which the bending stiffness is therefore reduced.

According to an alternative embodiment, the main axes of these solid areas form between them an angle of less than 10 °. In other words, these solid zones extend longitudinally diverging slightly and deviate as they approach the end of the board, so that the length of the characteristic slender portions increases as they approach the end of the board. board.

According to an alternative embodiment, provision may be made for the elongate portions to have a width, measured in the longitudinal direction, which decreases as it goes towards the extreme point of the raised end. In other words, the slender portions become narrower as you get closer to the end of the board, so that the added mass becomes smaller and smaller. At the same time, the influence on the stiffness in transverse bending is also reduced, in the extreme zone where this stiffness is not necessary.

-5In a specific form of execution, the elongated portions can form curves drawing alternating trapezoids, thus defining between two successive elongated portions of the recesses of hexagonal shape.

Advantageously in practice, the incorporated structural element may comprise a zone of reduced thickness formed in the region opposite to the extreme point of the raised end. In other words, the incorporated structural element may include a reservation intended to accommodate one or more layers of reinforcements which extend from the core, and partially overlap the incorporated structural element, on its underside or on its face. superior.

Brief description of the figures

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:

• Figure 1 is a summary perspective view of the stack of different layers used for the production of a ski according to the invention, incorporating the characteristic structural elements;

• Figures 2 to 6 are top views of different variants of an incorporated structural element.

Ways to realize the invention

FIG. 1 illustrates a board 1 which is composed of the stack of a lower assembly 3 on which the core 4 rests and of elements of incorporated structure 20, 21, which receive on the upper face the upper assembly 2. In the illustrated form, the lower assembly 3 comprises the sole 13 on the edges of which are placed the side edges 12 on which the edge elements rest 11. Between the edges is a reinforcing layer 14, which can for example be based on an impregnated fibrous material. In the illustrated form, the rear end of the board has an added element 16 which makes it possible to reinforce the heel of the board, which is often subjected to impacts during transport of the board.

-6The board of Figure 1 also includes an upper assembly which is composed of an upper layer of protection and decoration 5, which extends from the front end 6 ending the spatula, to the rear end 7 forming the rear end point of the heel. In the illustrated form, the decorative layer 5 has translucent or transparent patterns 17 located at the base of the recesses of the structural element which will be described later. This upper protective layer 5 covers a reinforcing layer 10, which extends over almost the entire length of the board, and ends with trapezoidal ends. Of course, other additional reinforcements can be envisaged with other geometries and various materials, without departing from the scope of the invention.

The upper assembly 2 and the lower assembly 3 are separated by the core 4 which extends over almost the entire length of the board, and which is extended forward and backward by structural elements incorporated 20, 21. The connection between these structural elements 20, 21 and the core is made by means of trapezoidal cutouts 22, 23, 24, 25 which allow to ensure a transverse setting of the assembly.

As mentioned, the invention relates more specifically to the geometry of the structural elements incorporated in the ends of the gliding board to form the tip of the tip and / or the tip of the heel. Different geometry variants can be envisaged, which respect the principle of having elongate portions extending transversely. These structural elements are positioned in continuity with the core of the board, at the front and at the rear, and preferably open out on the lateral sides of the gliding board to reinforce them. These structural elements have an openwork structure comprising through recesses of various geometry. Inside the board, these recesses are either filled with air, or at least partially filled with the material impregnation resin which flows during the board molding, or even any other low density material, such as a foam.

Thus, as illustrated in FIG. 2, the structural element 30 comprises several elongated portions 31-34, which extend transversely, from the regions 40, 41 forming the periphery of the element 30. These elongated portions 31-34 have a length L, measured transversely, that is to say perpendicular to the longitudinal axis 15 which is clearly greater, typically greater than five or even ten

-7 times the width l measured in the longitudinal direction. These various elongated portions 31-34 define between them and with respect to the rest of the structure of the recesses 35-39 which pass through the entire thickness of the structural element 30.

It is noted that the rigidity in longitudinal bending of the element 30 is essentially imparted by the rigidity of the portions 40, 41 which form the periphery of the element 30. Conversely, the rigidity in transverse bending results from the presence of the different elongated elements 31-34. The stiffness in longitudinal bending is therefore clearly less than the stiffness in transverse bending, which allows the tip to withstand the forces when the ski is tilted laterally and in particular when initiating and driving turns.

FIG. 3 illustrates an alternative embodiment in which the elongate portions 51-54 are not rectilinear as in the example in FIG. 2, but have a curved shape, while being connected to the portions 60, 61 forming the periphery of the element 50, at similar longitudinal levels. The through recesses 55-59 defined between the elongated portions 51-54 also have a geometry whose contours are curved, which makes it possible to modify the stiffnesses of the ends of the board and may be of aesthetic interest. Thanks to the curved shape of the elongated portions 51-54, the transverse flexural strength is slightly lower compared to that of the element in FIG. 2, with identical cross-section of material.

FIG. 4 illustrates another variant in which the elongate portions 71-73 have distinct geometries. More specifically, the elongate portion 71 is composed of a plurality of successive segments. These segments are oriented alternately in one direction and in the other with respect to a transverse axis, to give a zigzag shape. The elongate portion 71 is connected to the peripheral portions 80, 81 in two regions 82, 83 which are located at different levels longitudinally.

The element 70 also includes a slender portion 72, which extends between two points 84 and 85 of the peripheral zones 80, 81, which are situated at the same longitudinal level, like the example in FIG. 2.

The element 70 also includes a second zigzag-shaped portion 73, which is connected at the peripheral regions 80, 81 at two points 86, 87 which are located at different longitudinal levels. Note that the ends 83, 87 of the elongated portions 71, 73 are closer to the end 85 of the central elongated portion 72, in comparison with the ends 82, 86 of the same elongated portions 71, 73, which are more distant of the end 84 of the central longitudinal portion 72.

The mechanical behavior of this structural element 70 which is asymmetrical with respect to the longitudinal median axis of the ski, favors the supports on the side where the ends 83, 85, 87 of the elongated portions 71, 72, 73 are closest. Thus, the behavior of the ski is different depending on whether the board is in contact with snow at the right edge or the left edge.

In the variant illustrated in FIG. 5, the incorporated structural element 90 comprises elongated portions 91, 96, 97, 98 which are not rectilinear, but composed of a succession of segments 99, 92, 93, 94, 95 defining a wavy shape, and more precisely a succession of trapezoidal zones. The various elongated portions 91, 96, 97, 98 are connected to the peripheral portions 110, 111 at the same longitudinal level. In other words, the terminal segments 91, 95 of the elongate portions are aligned. Between these extreme segments 99, 121; 95, 125 define through recesses 101, 103 of polygonal shape, is partially hexagonal in the shape illustrated. These two recesses 101, 103 are connected by a narrower channel 102, defined between the segments 93, 123 forming the vertices of the trapezoidal zones most offset from the anchoring points of the corresponding elongate portions. Similarly, the recess 104 defined between the elongate portions 96, 97 has an entirely hexagonal shape, and is extended laterally by two open channels of small width.

From a mechanical point of view, the behavior of the structural element 90 is such that its stiffness in longitudinal bending is, as in the previous examples, essentially dependent on the width of the peripheral portions 110, 111. Conversely, the stiffness in transverse bending can be adjusted by adjusting the width, measured in the longitudinal direction of each of the elongate portions 91, 96-98.

FIG. 6 illustrates a particular embodiment, derived from that illustrated in FIG. 5. We thus find the elongated portions 151, 152, 153 formed of successive segments defining wavy curves with trapezoidal patterns, between which recesses of overall hexagonal shape 160, connected by narrow channels 161. In this embodiment, the elongated portions have a width, measured longitudinally, which decreases as it goes towards the end point of the raised end.

With regard to the recesses, in the longitudinal direction, particular patterns of recesses follow one another: a first pattern composed of two hexagons 160 connected by an open channel 161 alternates with a second pattern composed of a hexagon 160 extending on either side by two channels 161. The alternation of these profiles makes it possible to create the elongated portions of the type 151, 152 and 153.

In the illustrated form, the width and the length of the recesses formed both by the hexagonal zones and by the channels evolve progressively towards the end of the incorporated part, this in order to gradually reduce the inertia of the board by going towards its ends and thus improving the maneuverability of the board.

In this embodiment, the structural element 150 also includes solid areas 170, 174 whose main portion extends substantially parallel to the median longitudinal axis 15. These solid areas are symmetrical with respect to the longitudinal median axis of the board and are located relatively close to the lateral sides of the board to limit local deformation of the edges of the board and thus obtain better contact of the end of the board with the snow during the cornering phase, when the board is tilted on the edge. These solid portions are oriented in a slightly divergent manner and move away from one another, approaching the extreme point 157 of the incorporated structural element 150. In practice, the axes 190, 191 of these solid zones 174, 170 form an angle between them between 5 and 10 degrees.

These solid zones 170, 174 comprise the alternation of zones of greater width 171, and zones of narrower width 172, defined between the hexagonal recesses situated on either side. These narrower areas thus allow

-10decrease the rigidity in longitudinal bending of its solid portions, which have a predominant impact on the rigidity in longitudinal bending of the assembly. Thus, in the illustrated form, the elongate portions 151, 152, 153 are connected laterally to these solid areas 170, 174, which are themselves separated from the peripheral portions 155, 156 by a set of recesses 158, of hexagonal shape or derivative.

In the region of the structural element 150 located closest to the core, hexagonal recesses 184, 185, 186 are also defined, and connected by narrow channels 188, so as to reduce the rigidity in longitudinal bending. Other recesses 182, with a completely hexagonal outline, are also provided in order to lighten the element 150. In this region, the structural element 150 has a lesser thickness, the periphery of which is delimited by a recess 180, so that inside this recess, the thickness of the element 150 is less, so as to accommodate the thickness of the reinforcement 10. This recess 180 has a trapezoidal shape, in order to ensure the transverse blocking reinforcement. The various structural elements are preferably made of plastic materials and can be obtained by injection, by cutting or three-dimensional printing.

Of course, the structural element described here for its integration into the tip of a board can be adapted in size and thickness for its incorporation inside the heel area, which is slightly raised. The gliding board can have either a single structural element at one of its ends positioned at the heel or at the tip, or it can have two structural elements, at the heel and at the spatula.

The structural elements according to the invention are all the more advantageous for optimizing not only the behavior in longitudinal bending and in transverse bending of the ends of a gliding board, but also the inertia of its ends, and this in particular for a wide board. A wide board for an alpine ski will be understood to mean a board which has a maximum width in the area of the tip greater than 110 mm and a maximum width in the area of the heel greater than 100mm.

It follows from the above that the gliding board according to the invention has the advantage of having a spatula which is not only lightened, but which has

-11 also a differentiated behavior of stiffness in longitudinal and transverse bending. In addition, it has an attractive aesthetic appearance, because it allows the passage of light through the tip and the heel.

Claims (10)

5 1 / Gliding board (1), including a structural element (20, 21) located in a raised end of the board, said element (20, 21) having an openwork structure and having through recesses (160), characterized in that at least part of the recesses (160) are defined between two elongated portions (151, 152) extending substantially perpendicular to the axis (15) of the board. 2 / Gliding board according to claim elongated (31-34) are rectilinear. 3 / Gliding board according to claim 15 elongated (51, 54) have a wavy shape. characterized in that the portions characterized in that the portions 4 / Gliding board according to claim 1 characterized in that the elongated portions (71, 73; 91) are formed of successive segments, two consecutive segments (99, 92, 93, 94, 95) forming between them a non-zero angle . 5 / Gliding board according to claim 1 characterized in that the elongated portions (31-34; 91, 96, 98) extend between two points located at the same longitudinal level 25 6 / gliding board according to claim 1 characterized in that the elongated portions (31-34) extend between two points located on the peripheral zone of said structural element. -137 / Gliding board according to claim 1 characterized in that the structural element (150) comprises two solid zones (170, 176) oriented substantially longitudinally, and between which the elongated portions extend (151, 152, 153 ). 8 / Gliding board according to claim 7 characterized in that the solid areas (170) have regions of narrower width (172). 9 / Gliding board according to claim 7 characterized in that the main axes (190, 191) of said solid areas form between them an angle less than 10 °. 10 / Gliding board according to claim 1 characterized in that the elongate portions have a width, measured longitudinally, which decreases as it goes towards the extreme point of the raised end. 11 / Gliding board according to claim 4, characterized in that the elongate portions define between them recesses (160) of hexagonal shape. 12 / Gliding board according to claim 1 characterized in that it comprises a region (181) of reduced thickness formed in the region opposite to the extreme point of the raised end. 1/3 CM