EP3632513B1 - Glideboard with injected core provided with longitudinal reinforcing elements - Google Patents

Description

Technical area

The invention relates to the field of sliding sports on snow or water, and in particular skiing, snowboarding or kite surfing. It is more specifically aimed at a board structure produced by injection methods, in which the core is formed during the molding of the board, by the chemical reaction of components forming a thermosetting foam.

It concerns more specifically particular arrangements allowing the positioning and maintaining in position of mechanical reinforcements intended to improve the properties in particular of resistance to longitudinal bending and torsion of such boards.

Previous techniques

Generally speaking, a gliding board comprises a lower assembly, including a gliding sole, possibly edged with edges, associated with one or more layers of mechanical reinforcements. The board also includes an upper assembly, also comprising one or more layers of mechanical reinforcement, most often topped by an outer layer ensuring decoration and/or protection of the board from the external environment.

These upper and lower assemblies are separated by a core, which separates the layers of mechanical reinforcement from the neutral fiber of the board.

This core can be produced by a prefabricated part, or with regard to the invention by its in-situ formation in the board manufacturing mold during manufacture of the board. So, in this case, the lower and upper assemblies are positioned in the mold, and components are introduced into the space separating these lower and upper assemblies to form an expansive foam, which presses the lower and upper assemblies against the walls of the mold.

Compared to boards with machined or prefabricated cores, the use of injected cores presents an advantage in terms of costs since it is not necessary to produce a part with a precise geometry before molding since the core takes the shape imposed by the mold.

However, this solution has some disadvantages since the mechanical properties of the foam are lower than those of the materials used to make pre-machined cores, generally based on wood.

Another disadvantage of injected cores lies in their homogeneous appearance, meaning that it is impossible to add reinforcements located in the central or intermediate part in width. Indeed, during the chemical reaction generating the expanding foam, the mechanical stresses exerted are such that any element located between the upper assembly and the lower assembly is inevitably ultimately pressed against one or the other of these two sets, without it being possible to predict it in advance.

The problem of positioning reinforcing elements inside the mold, prior to injection of the core has already been dealt with for certain types of reinforcements by the solutions described in the documents EP 1 421 978 , And EP 1 504 796 . In these documents, horizontal reinforcing elements, that is to say parallel to the plane of the sole of the board, are placed in the mold before injection of the core, resting on shoulders formed on the internal faces of the elements. of singing. Thus, the edges of these reinforcing elements are held in position, so that during the expansion of the foam forming the core, this reinforcing element remains at the vertical level which was fixed when closing the mold.

The disadvantage of this solution lies in the fact that it is only suitable for sufficiently wide reinforcing elements which extend transversely from one edge to another, and that it is therefore not suitable for the installation of reinforcing elements which would be located at intermediate levels transversely, and whose dimensions ensure that they do not come into contact with the edges.

Presentation of the invention

• un ensemble supérieur comportant au moins une couche de renfort et éventuellement d'une couche supérieure de décoration et de protection ;
• un ensemble inférieur comportant au moins une couche de renfort et d'une semelle de glisse, éventuellement bordée de carres ;
• un noyau réalisé en un matériau injecté entre les ensembles inférieur et supérieur et bordé latéralement d'éléments de chant.

To solve these problems, the Applicant has developed a gliding board which includes:

• an upper assembly comprising at least one reinforcing layer and possibly an upper layer of decoration and protection;
• a lower assembly comprising at least one reinforcing layer and a gliding sole, possibly edged with edges;
• a core made of a material injected between the lower and upper assemblies and lined laterally with edge elements.

In accordance with the invention, this board is characterized in that it comprises at least one holding piece extending from one of the edge elements towards the interior of the core, this holding piece having a groove open towards the high. The board also includes a longitudinal reinforcing element inserted in this groove. In other words, this longitudinal reinforcing element extends substantially vertically inside the core, along the longitudinal axis of the board (Ox) and parallel to the median vertical plane of the board Oxz. The portion of the longitudinal reinforcing element, extending upwards or downwards, beyond the opening of the groove, has its two opposite lateral faces in contact with the injected material of the core.

In other words, the invention consists of producing a sliding board by inserting reinforcing elements inside the structure, placed in holding members which are linked to the edges, and which allow the positioning of these reinforcing elements at an intermediate level transversally.

In other words, the reinforcing elements are embedded inside the injected core, without them having moved during the injection operation since their lateral position is blocked by the characteristic retaining parts. The reinforcing elements therefore cut the core into several parallel beams oriented parallel to the Oxz plane, between which these reinforcing elements are interposed.

Thus, the invention allows the incorporation into an injected core of localized reinforcing elements, which increase its resistance to crushing, these reinforcements being arranged optimally according to the distribution of the stresses to be supported.

Preferably, the reinforcing element extends to the upper assembly if the groove is open upwards, or the lower assembly if it is open downwards.

Advantageously in practice, the holding part rests on the lower assembly, so that the forces exerted from the upper face of the board, directly above the reinforcing element, are transmitted via the latter to the part maintaining, which in turn transmits them to the lower assembly.

In practice, the characteristic holding part can be constructed in various ways, while allowing the precise positioning of the groove which accommodates the reinforcements.

Thus, in a first embodiment, the holding part may include hooking portions which cooperate with portions of complementary shape present on the internal face of the edge element. In other words, the edge has on its side facing the core lugs or cleats on which the complementary parts are mounted, so as to become mechanically attached to the edge. In this configuration, it is possible to use different holding pieces, particularly with regard to the positioning of the groove, for the same edge element.

In another embodiment, the retaining part can form a protrusion from the internal face of the edge element. In other words, the retaining part is monolithic or one-piece with the edge element, which avoids any assembly or positioning operation of the part intended to receive the characteristic reinforcements.

According to another characteristic of the invention, it is possible for the holding part to include through recesses in which the material of the core is present. In other words, the retaining part is pierced in such a way that the expandable foam which forms the core flows through these holes during its expansion, so as to form bridges within the core, which ensure improved anchoring of the retaining part. maintenance.

The geometry of the holding part, and in particular of the zone which forms the groove, can be declined in different ways.

Thus, it is possible that this holding part comprises several grooves arranged parallel, so as to accommodate several longitudinal reinforcement elements inserted in these grooves. It is also possible to use this holding piece with several grooves to create different board sizes and structures, by positioning the reinforcement(s) in the most appropriate grooves.

In practice, the groove can have substantially vertical and parallel walls, possibly with ribs oriented vertically, so as to ensure tightening and blocking of the reinforcing element which is inserted, without requiring significant efforts. The groove can also have walls inclined at a non-zero angle relative to the perpendicular to the sliding sole. In this case, the groove accommodates longitudinal reinforcement elements which are oriented with their high end either towards the inside or towards the outside of the core relative to their low end.

In practice, the use of this retaining part allows the installation of longitudinal reinforcement elements which extend upwards to the upper assembly. The reinforcing element therefore receives the supports directly from the upper assembly, and in particular the reinforcing layers of the latter. The contact can be direct or indirect by the interposition of a bonding layer, or even by the presence of a very thin thickness of the core foam which interferes between the top of the longitudinal reinforcing element and the upper assembly, so as to ensure effective bonding of these two reinforcements to each other.

In practice, the longitudinal reinforcements which can be used are chosen to present optimized mechanical properties. In practice, these reinforcing elements can be made of wood, or of a composite material, typically based on glass or carbon fibers. They thus make it possible to increase the stiffness in longitudinal bending, as well as the torsional stiffness, and the resistance to crushing, with the lowest possible impact on the weight of the board. To do this, we will favor longitudinal reinforcing elements which have a maximum height at least three times greater than their width in the case of composite materials, and greater than their width in the case of wooden material.

The positioning of the holding parts can be optimized according to the dimensioning of the board, and the mechanical constraints to be supported during the expansion of the core. Thus, it can be expected that the board includes at least two holding pieces associated with each edge, and arranged at offset longitudinal levels. In the case of particularly long boards, it is possible to provide one or more additional holding pieces located at an intermediate level in length. In practice, the longitudinal reinforcing element can be positioned more or less forward relative to the edge element, to increase the mechanical properties in the area where it is present.

In practice, the risks of unexpected movement of the longitudinal reinforcement during the injection of the core are minimized, by choosing to position the middle of the longitudinal reinforcing element substantially in the middle of the two holding pieces furthest apart longitudinally.

Summary description of the drawings

• La figure 1 est une vue en perspective sommaire d'un ski réalisé conformément à l'invention.
• La figure 2 est une vue en coupe transversale selon le plan II - II' de la figure 1.
• La figure 3 est une vue en coupe transversale de la planche de la figure 1 selon le plan III - III'.
• Les figures 4, 5 et 6 sont des vues en perspective sommaire de pièces de maintien selon trois modes de réalisation différents.
• La figure 7 est une vue de dessus montrant l'assemblage de la pièce de la figure 5 associée à un élément de chant.
• La figure 8 est une vue en coupe selon le plan IV - IV' de la figure 1.
• La figure 9 est une vue analogue à la figure 8 d'une variante de réalisation.

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

• There figure 1 is a summary perspective view of a ski produced in accordance with the invention.
• There figure 2 is a cross-sectional view along plane II - II' of the figure 1 .
• There Figure 3 is a cross-sectional view of the board of the figure 1 according to plan III - III'.
• THE figures 4, 5 and 6 are summary perspective views of holding parts according to three different embodiments.
• There Figure 7 is a top view showing the assembly of the part of the Figure 5 associated with an element of singing.
• There figure 8 is a sectional view according to plan IV - IV' of the figure 1 .
• There Figure 9 is a view analogous to the figure 8 of an alternative embodiment.

Ways of making the invention

The present invention can be implemented on different types of sliding boards, and in particular an alpine ski, as illustrated in figure 1 . Such a ski 1 has two raised ends, namely on the front side a spatula 2, and on the rear side, a heel 3. The central zone, or pad 4, is intended to receive the elements of the binding.

More precisely, and as illustrated in figure 2 , such a ski comprises a lower assembly 10 including a sliding sole 11 intended to come into contact with the snow, and bordered by side edges 13, 14, the fins 15, 16 of which rest on the upper face of the sole. We will not depart from the scope of the invention if the ski or the gliding board does not have edges, in particular in the case of short skis, cross-country skis or a water gliding board.

The sole 11 is covered with a reinforcing layer 12 which can be made from different materials having high rigidity, such as for example composite or metallic materials. Of course, the geometry of these reinforcements, as well as their number can be varied depending on the mechanical properties desired for the board.

The ski 1 also comprises an upper assembly 20 including in the form illustrated an upper layer of decoration and protection 21. In the form illustrated, this upper layer 21 extends laterally down the side of the ski to rest on the top of a song element 25,26. In other words, this construction is of the “single+shell” type. In this embodiment, the height of the edges 25,26 is less than the height of the core in a cross section of the ski. Of course, the invention also covers variants in which the upper layer of protection is substantially horizontal, with edge elements which have a height substantially equal to that of the board, corresponding to so-called "sandwich" structures, and in which the edge elements have a height slightly greater than that of the core, measured in a cross section of the ski.

In the form illustrated, the upper assembly 20 also includes a reinforcing layer 22, arranged under the upper protective layer 21. The shape and materials constituting this reinforcement can be varied depending on the desired mechanical properties. Generally, these reinforcements are composite materials based on glass or carbon fibers for example, embedded in a resin, or even are metallic materials. It is also possible to combine several reinforcing layers of different or similar geometries and natures.

The ski 1 also includes edge elements 25, 26, which rest on the cord of the edges 13, 14, and which form the side face of the board. Between the upper 20 and lower 10 assemblies and the side edges 25, 26, is the core 30 of the board, which is made of a typically polyurethane foam (abbreviated PU), or more generally of an expanding foam inside this volume, to press the upper assembly 10, the lower assembly 20 and the edges 15, 16 against the walls of the mold.

In accordance with the invention, this ski also comprises two longitudinal reinforcing elements 31, 32 which extend vertically, between the lower 12 and upper 22 reinforcements over all or part of the length of the ski, inside the core of the ski. ski. Interstices 33, 34 are provided, respectively between the upper reinforcement 22 and the upper surface of the longitudinal reinforcement as well as between the lower reinforcement 12 and the lower surface of the longitudinal reinforcement, to allow the passage of the foam of the core 30 in order to ensure bonding of these longitudinal reinforcements 31, 32 on the adjacent elements, in this case the lower 12 and upper 22 reinforcements.

These longitudinal reinforcements 31, 32 are made of a material having mechanical properties of resistance to crushing and rigidity which are greater than those of the material of the core 30. Typically, it may be wood, or even materials composites including fibers of high tenacity, oriented longitudinally, that is to say parallel to the longitudinal axis of the ski, to increase the resistance to longitudinal bending of the board. This longitudinal reinforcement can also include fibers oriented vertically, that is to say perpendicular to the sliding sole, so as to increase the crushing resistance of the ski. The width of these longitudinal reinforcements, measured in one direction transverse is optimized to limit the impact of the weight of these reinforcements on that of the ski.

In accordance with the invention, these longitudinal reinforcements 31, 32 are elongated elements oriented in the longitudinal direction (Ox) of the ski and positioned vertically, in a plane parallel to the plane (Oxz), that is to say they separate the core transversely into several juxtaposed longitudinal beams. In other words, these longitudinal reinforcements are offset laterally from the edges towards the center of the core. In the illustrated embodiment, the two longitudinal reinforcements 31, 32 are offset from the internal wall of the edge, respectively 25,26 towards the center of the core by a distance of approximately 8 to 15mm. This distance is chosen according to the mechanical properties sought for the ski. Thus, in the transverse direction, from one edge to the other, the core of the ski is therefore composed of a longitudinal beam of PU foam, then a longitudinal reinforcement beam of wood or composite, followed by a zone central PU foam beam, then another longitudinal reinforcement beam in wood or composite and finally another longitudinal PU foam beam. In this way, a longitudinal reinforcement is framed on either side by the foam material of the core, and is embedded in the core. Thus, due to the two longitudinal reinforcements 31,32, the injected material of the core is separated into three substantially parallel parts or beams, namely a central beam 36 and two lateral beams 35,37.

In accordance with the invention, these longitudinal reinforcements 31, 32 are held in position during the molding operation, to allow the material of the expandable foam of the core to spread throughout the entire volume of the future core, and therefore between the longitudinal reinforcements, avoiding unexpectedly moving the characteristic reinforcements.

To do this, the ski includes holding parts 40, which are as illustrated in Figure 3 placed on top of the lower assembly 10, and connected to the edge elements 25, 26. As illustrated in Figure 3 , the longitudinal reinforcement 31 is held in position by a holding element 40 connected to one of the edge elements 25 while the other longitudinal element 32 is held in position by another holding element 140 connected to the other edge element 26. These parts support are preferably made of lightweight materials, such as plastic. These holding parts 40 comprise a groove 41 open upwards, defined between two walls 42, 43, and which accommodates the longitudinal reinforcing element 31. This groove can, in a form not shown, be open downwards, the reinforcement being then preferably pinched in the holding parts so as not to fall during molding. The opening of the groove 41 is oriented vertically along the axis Oz but we would not depart from the scope of the invention if its opening were inclined relative to the vertical (axis Oz), preferably between + or - 45 degrees, so that the longitudinal reinforcement is itself inclined in the core of the ski. The holding part 40 comprises a hooking portion 50 allowing connection to the edge element 25, by positioning this hook portion 50 on a portion 27 of the edge element 25 forming an inward projection of the structure of the ski. The retaining part can be fitted onto the portion 27 of the edge element 25 or can be a one-piece element with the edge element 25.

More precisely, and as illustrated in Figure 4 , the part 40 comprises two substantially vertical walls 42, 43 and whose facing faces have vertical ribs 46 making it possible to lock in position, by pinching, compression or snap-fastening, the reinforcing element which has been introduced into the defined groove 41 between the walls 42, 43. In this embodiment, this groove 41 preferably receives a wooden reinforcing element with a height of between 5 and 15 mm, and a thickness of between 4 and 15 mm corresponding to the width of the groove 41. Of course, the invention covers variants in which the height (measured along the axis Oz) of the longitudinal reinforcing element is constant, or varies according to the length of the latter, to adapt to the thickness of the board. The horizontal wall 44 which ensures the connection between the vertical walls 42, 43 rest on the lower assembly 10, and has in the form illustrated an opening 45, allowing the foam of the core during expansion to interfere in contact of the vertical reinforcing element 31 to ensure effective bonding of the holding part 40 with the lower assembly 10. The geometry of the lower face of the vertical wall 44 can be arranged to facilitate the creep of this resin by comprising for example traffic channels.

The length measured in the longitudinal direction Ox of the groove 41 is provided to ensure effective maintenance of the reinforcement with respect to the stresses exerted by the foam of the core during expansion. In particular, a length of between 5 and 12 mm is satisfactory. In this case, two holding pieces can be provided to hold a longitudinal reinforcement element, these holding pieces each being positioned a few centimeters from the front and rear ends of the longitudinal reinforcement. Flying buttresses 47 can be provided to increase the rigidity of the wall 43 and prevent its deformation during the expansion of the core foam.

In the form illustrated, the holding part 40 comprises a zone 50 ensuring attachment to the edge element 25,26. More precisely, this zone 50 comprises portions in the form of hooks 53, 54 defining an opening 52 of greater width than the distance separating the two hooked portions 53, 54. This opening 52 is intended to receive a bulging portion of complementary shape 28 of constant horizontal section, and connected to the edge element 25 by a connection portion 29. This portion 28 is of height greater than or equal to the thickness of the hooking portion 50, to avoid any disconnection during phase d expansion of the core foam. As illustrated in Figure 9 , when the retaining part 40 is mounted on the protrusion 27 of the edge element 25, the transverse position along the axis Oy of the groove 41 is fixed, so as to block the longitudinal reinforcing element 31 when it is mounted in groove 41.

According to a complementary characteristic, this attachment portion 50 comprises through recesses 51, allowing the foam of the current core expansion to pass through this attachment portion, and thus ensure effective anchoring of the holding part relative to the rest of the core.

Of course, different variants are possible for the constitution of the holding part, as illustrated in figures 5 and 6 . Thus, the Figure 5 illustrates a holding part 70, in which the width of the groove 71 is less than that of the part of the Figure 5 , so as to accommodate a vertical reinforcing element of thinner thickness typically based on a composite material including high tenacity fibers. In this case, the width of this groove 71 is a few millimeters, between 0.5 to 3 mm, to receive a longitudinal reinforcing element 31.32 made of glass fibers or carbon fibers which has a thickness similar to the width of the groove 71. Complementarily, and as illustrated in Figure 6 , the holding part 80 may include several grooves 81, 82, 83 offset transversely, making it possible to accommodate several longitudinal reinforcing elements, or to adjust the transverse position of the longitudinal reinforcing element, according to the desired mechanical properties.

This part 80 can also include vertical through recesses 86, 87, defined between the vertical walls 84, 85 ; 88, 89 of two adjacent grooves, so as to allow passage of the core foam and effective anchoring of the retaining part in the core.

The positioning of the longitudinal reinforcement elements can be optimized thanks to the retaining parts according to the invention. Thus, as illustrated in figure 8 , the longitudinal reinforcing element 31 is held in position by two holding pieces 40, 140 which are arranged near the ends of the element 31. In the form illustrated in Figure 9 , the longitudinal reinforcing element 231 is held in position by three holding pieces 240,241,242, the grooves of which are located at substantially identical distances from the dimension line. Thus, the reinforcing element 231 is slightly curved to match the curvature of this sideline.

In the examples illustrated in the figures, the groove of the holding elements is oriented with its opening upwards, and the reinforcing elements extending upwards, up to close to or in contact with the upper assembly, but the The invention also covers variants where the groove is arranged in an opposite configuration, with its opening facing downwards, and reinforcements extending close to or in contact with the lower assembly.
It appears from the above that the structure of the gliding board according to the invention makes it possible to integrate longitudinal and substantially vertical mechanical reinforcements in a ski or a gliding board, or more precisely inside the core of the ski or the gliding board, where the core is injected around these reinforcements, this with a large latitude of transverse positioning, and an assurance of maintaining the position of this or these reinforcements during the core injection operation.

Claims (14)

1. A sliding board (1), comprising:

   • an upper assembly (20) comprising at least one reinforcing layer (22);

   • a lower assembly (10) comprising at least one reinforcing layer (12) and a sliding sole (11);

   • a core (30) made of a material injected between said lower (10) and upper (20) assemblies, and laterally bordered by edge elements (25, 26);

   • at least one holding piece (40) extending from one of the edge elements (25) towards the inside of the core (30), said holding piece having a groove (41) open upwards or downwards;

   • and a longitudinal reinforcing element (31,32) positioned in said groove (41) and extending longitudinally into the injected material of the core,

   characterised in that the portion
   of the longitudinal reinforcement element (31,32) extending beyond the opening of the groove upwards or downwards have two opposite lateral faces in contact with the injected material of the core.
2. The sliding board according to claim 1, characterised in that the holding part (40) rests on the lower assembly (10).
3. The sliding board according to claim 1, characterised in that the longitudinal reinforcing element (31, 32) extends from the groove to the upper assembly (20).
4. The sliding board according to claim 1, characterised in that the holding piece (40) comprises hooking portions (50) cooperating with portions (28) of complementary shape present on the inner face of the edge element (25).
5. The sliding board according to claim 1, characterised in that the holding piece forms a protuberance of the inner face of the edge element.
6. The sliding board according to any one of the preceding claims, characterised in that the holding piece comprises through-recesses (51) in which the material of the core (30) is present.
7. The sliding board according to any one of the preceding claims, characterised in that the holding piece (80) comprises a plurality of grooves (81, 82, 83) arranged in parallel, and a plurality of longitudinal reinforcing elements inserted into said plurality of grooves.
8. The sliding board according to any one of the preceding claims, characterised in that the groove (41) has substantially vertical and parallel walls (42, 43).
9. The sliding board according to any one of the preceding claims, characterised in that the groove has walls inclined by a non-zero angle with respect to the perpendicular to the sliding sole.
10. The sliding board according to any one of the preceding claims, characterised in that the longitudinal reinforcing element (31) has a maximum height at least 3 times greater than its width.
11. The sliding board according to any one of the preceding claims, characterised in that the longitudinal reinforcing element is made of wood or a composite material, in particular based on glass or carbon fibres.
12. The sliding board according to any one of the preceding claims, characterised in that it comprises at least two holding parts associated with each edge element, and arranged at offset longitudinal levels.
13. The sliding board according to claim 12, characterised in that the middle of the longitudinal reinforcing element is located substantially in the middle of the two most distant holding pieces.
14. The sliding board according to any one of the preceding claims, characterised in that it comprises two longitudinal reinforcing elements (31, 32), one of the longitudinal reinforcing elements (31) being held in position by a holding element (40) connected to one of the edge elements (25) of the board, and the other longitudinal reinforcing element (32) being held in position by a holding element (140) connected to the other edge element (26) of the board, thus separating the injected material of the core into three parts, a central part (36) and two lateral parts (35, 37).

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