EP2055358A1 - Snowboard in which the slider has a groove - Google Patents

Abstract

The board has a lower layer forming a slider (2) that includes a groove (3) oriented parallely to a median longitudinal axis (4) of the board. The groove forms a depression with respect to the rest of a plane of the bottom of the slide. The layer has an additional element whose shape partially corresponds to that of the groove, where the element forms a central portion of the layer. The additional element is made of material distinct from that of a main element, where the material possess weak frictional coefficient with respect to snow.

Description

Technical area

The invention relates to the field of snow sports and more particularly sports using a snowboard such as downhill skiing in particular, but also snowboarding or even cross-country skiing.

It relates more particularly to a method of manufacturing the sole glide such boards, to obtain a highlight of the grooves carved on its surface.

Previous techniques

In general, the gliding boards and in particular the alpine skis may have grooves which are oriented substantially parallel to the sliding direction, that is to say generally along the longitudinal axis of the ski. These grooves form a depression relative to the rest of the plane of the gliding base and are intended to improve the stability of the trajectory. Indeed, the slight hollow formed by this groove is at least partially filled with snow which creates a kind of rail on which slides the ski. It is less likely to deviate from the direct path.

Different methods can be used to create these grooves. Thus, in the past, these grooves were formed by machining the sliding surface. This simple technique was effective for skis made of wood, and more generally by skis whose gliding surface was formed by the underside of the core.

On the other hand, for modern structures resulting from the stacking of different layers, this machining is no longer really appropriate.

Indeed, the structures combining different materials have the advantage of being able to use materials whose properties are optimized for the function corresponding to their location.

The gliding sole is thus generally made of a material having a low coefficient of friction with respect to snow, while conversely, the core may be made of a material ensuring the filling of the volume of the board, and allowing and to position mechanical reinforcing elements to impart the desired stiffness to the ski.

Thus, machining of the lower layer forming the sliding sole is limited, given the thickness of this layer at the groove. It causes a decrease in this thickness, which is not desirable because it weakens the sole. Thus, methods of making the grooves during molding of the board have been developed. In this case, the bottom of the mold accommodating the layer forming the sliding sole has protruding areas having a shape complementary to future grooves that will be formed during molding.

The lower layer forming the gliding base thus deforms during molding and maintains a constant thickness.

The core of the board can be made in different ways, for example from a pre-existing element, which thus comprises recesses in line with future grooves. The ski can also be made by an injection method in which the core material expands itself just press the sole glide on the reliefs of the bottom of the mold.

One of the objectives of the invention is to allow the development of the grooves present under the board.

Furthermore, it is known that at the molding outlet, the gliding sole has a surface condition that is unsuitable for sliding. The sole must therefore undergo several wheeled passages which aim to structure the ski sole by generating oriented micro-reliefs and thus eliminate a surface condition that is too smooth or rough in a random manner.

The bottom of the groove being an area set back from the rest of the sole, it is inaccessible for grinding operations. Thus, the bottom of the groove can not be treated, and retains its surface state resulting from molding, which is not conducive to sliding. At the extreme, the snow that can stick to the sole at the groove can hinder sliding. This disadvantage is all the more marked that the area occupied by the groove or grooves is important.

Another object of the invention is to overcome this disadvantage.

Presentation of the invention

The invention therefore relates to a gliding board which has a lower layer forming the sliding sole which comprises at least one groove oriented substantially parallel to the direction of sliding. This groove forms a depression relative to the rest of the gliding sole which is substantially flat.

According to the invention, the layer forming the sliding sole has a fraction whose shape corresponds at least partially to that of the groove or grooves. This fraction is made of a material distinct from the material of which the rest of the lower layer is formed.

In other words, the invention consists in using a gliding sole which is constituted by the assembly of different elements having distinct properties, forming a layer attached under the core of the board.

We can choose materials that have different mechanical properties. In this case, it is thus possible to use at the groove, a material which has a better coefficient of sliding on the snow, which compensates for the fact that the bottom of the groove can not undergo structuring by passage to the grinding wheel.

It is also possible to use materials of different colors, which therefore have different visual aspects. One of these fractions is cut according to the contour of the (or) grooves of the sole which it adopts the curvature during the manufacture of the board, to make it apparent.

The specific fraction has a color sufficiently distinct from the rest of the sole to highlight the groove. Thus, the boundary between the two differently colored materials is in close proximity to the groove boundaries.

This construction can adapt to any kind of groove geometry, for example grooves having a variable width and / or depth along the length of the board, as well as multiple grooves, aligned or not, as described in the document EP 1 053 124 . Similarly, the fraction of the sole that is cut according to the shape of the groove can correspond exactly to the same profile, and have the entirety of its outline which is in line with the limits of the groove. It is also possible that this fraction completely covers the groove, having only a portion of its contour coinciding with the groove boundaries, thus a portion of the characteristic element extending beyond the groove.

Advantageously in practice, it is possible to provide a sealing film covering the boundary zone between the different fractions of the layer forming the gliding sole, on the inner side of the board, and this in order to avoid any release of resin contained in adjacent materials during molding or injection operations.

However, this sealing film is not absolutely essential, insofar as the gliding sole undergoes a passage to the grinding wheel after manufacture. This passage to the grinding wheel thus eliminates any burrs that could have crossed in case of absence of sealing film.

In practice, the assembly of the different fractions constituting the gliding sole can be done by various means and in particular by adhesive tapes or openwork gluing elements, having an almost zero influence on the mechanical properties of the ski.

The bottom of the groove being an area set back from the rest of the sole, it is difficult to access for grinding operations. In this case, special arrangements can be made for the material present in the groove. Thus, it is possible to subject it to a particular structuring operation, so as to give it a surface condition improving its sliding properties and comparable to that of the rest of the gliding sole. It is also possible to use a material having a better coefficient of sliding with the snow than that used for the rest of the sole, which can be chosen for other properties and in particular its resistance to abrasion.

In practice, the board can include different types of reinforcement variables according to the desired mechanical properties and the manufacturing process. These reinforcements may be fibrous based, and include a polymerized resin. In this case, the reinforcement conforms to the shape of the groove during molding or injection operations. The reinforcement may also be metal-based, and have a central opening in which is embedded the groove of the sole during molding or injection.

Brief description of the figures

• La figure 1 est une vue de dessous d'un ski conforme à l'invention.
• La figure 2 est une vue montrant les deux éléments constituant la couche formant la semelle de glisse, illustrée détachés l'un de l'autre.
• La figure 3 est une vue en coupe transversale de la couche formant la semelle de glisse.
• La figure 4 est une vue en coupe d'un fond de moule dans lequel est mis en place la couche formant la semelle de glisse, avant la mise en place des autres éléments constitutifs du ski.
• La figure 5 est une vue schématique en coupe d'un moule montrant la mise en place des éléments venant reposer sur la semelle de glisse.
• Les figures 6 et 7 sont des vues en coupe transversales de skis obtenus conformément à l'invention.

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

• The figure 1 is a bottom view of a ski according to the invention.
• The figure 2 is a view showing the two elements constituting the layer forming the sliding sole, shown detached from one another.
• The figure 3 is a cross-sectional view of the layer forming the gliding sole.
• The figure 4 is a sectional view of a mold bottom in which is set up the layer forming the gliding sole, before the establishment of the other components of the ski.
• The figure 5 is a schematic sectional view of a mold showing the establishment of elements coming to rest on the gliding sole.
• The Figures 6 and 7 are cross-sectional views of skis obtained according to the invention.

In all the figures, certain dimensions, and in particular the thickness of the characteristic groove have been accentuated to facilitate understanding and can therefore deviate from reality.

Way of realizing the invention

As illustrated in figure 1 , the invention is applied to an alpine ski (1) whose gliding sole (2) has a groove (3). This groove (3) is dug under the gliding surface, and extends parallel to the median longitudinal axis (4) of the ski, which corresponds to the direction of progression and sliding.

In the form illustrated in figure 1 , the ski (1) has only one groove (3), but the principle of the invention can extend to skis having a higher number of grooves, without limitation on their geometry or their location.

The gliding sole (2) is constituted by a layer made of a material having a low coefficient of friction with respect to snow. This layer extends from the front to the back of the ski, and is laterally bordered with metal edges (5).

According to the invention, and as illustrated in figure 2 , this layer is constituted by the assembly of two elements, namely, a first element (11) to the dimensions of the groove, and a second element (10) for forming the remainder of the sliding surface, which is substantially planar, and which has a recess (12) of the size of the first element (11).

These two elements (10, 11) are produced by conventional methods, for example using laser cutting or cutting with blades, to ensure a coincidence of the cutting patterns, and an assembly without play.

Typically, the main element (10) of the gliding base (2) can be made of a material such as high density polyethylene, obtained by sintering, cutting or extrusion, and preferably loaded with graphite. This material is pigmented to possess a given color. The additional element (11) which forms the central fraction of the gliding layer is made of a separate material. It can be a material that has a different chemical composition, by adding specific charges. It may also be a material which has a chemical composition similar to that of the main element material (10), but which has been given a different pigmentation, giving it a distinct color.

In some cases, the material of one and / or the other fractions of the soleplate may also be transparent in order to reveal the underlying layers, and in particular any reinforcements located under the core.

After cutting, the two elements (10, 11) are assembled as shown in FIG. figure 3 to form a single layer (2). The assembly of the two elements (10, 11) can be done in various ways, and in particular by the introduction of an adhesive element (15) which also ensures a seal at the zones (16, 17) of boundary between the two elements (10, 11).

In an alternative embodiment, not shown in the figures, an additional element forming an adhesive network may be placed on the upper face of the future gliding layer (2), in order to ensure the joining of the two elements. This openwork network does not prevent the contact between the gliding layer (2) and the elements, in particular adhesives, intended to cover the gliding sole.

After assembly, and as illustrated in figure 4 , the gliding layer (2) is placed in a mold (20) for the manufacture of the ski. The bottom of the mold (20) has a boss (21) in the shape complementary to the groove.

Because the gliding layer (2) is flat, and not yet deformed, it has a slightly greater width than it will occupy once the finished ski. This is why after the placing of the metal edges (5) which are held in the mold by magnetic systems, the layer (2) of the sole is very slightly curved. In practice, the layer (2) has a thickness of about one millimeter. The groove has a depth that can vary over the length and / or the width of the board, between the tenth of a millimeter, beyond the millimeter. In the latter case, the depth of the groove is greater than the thickness of the gliding layer (2). This depth and thickness are measured after grinding by comparing the altitudes of the structured sliding surfaces. The depth of the groove can also be measured by difference in altitude on the upper face of the gliding layer, between the groove area and the remainder of the sole.

The central element (3) forming the fraction in line with the future groove is opposite the boss of the bottom of the mold.

As illustrated by way of example at figure 5 the bottom (20) of the mold receives the different constituent elements of the ski.

The ski can thus include a layer (30) of lower reinforcement, typically based on a fibrous material impregnated with resin, which will adopt its final shape during molding, by polymerization of the resin. In the form illustrated in figure 5 , the core is realized by a pre-existing element, which includes under its face lower a groove (32) corresponding to the groove (3) that is sought to form under the gliding sole.

Always at the figure 5 this core (31) is laterally bordered by longitudinal reinforcing elements (33) forming the edges. It is covered with a reinforcing layer (37), itself covered with a layer (38) upper protection and decoration.

During the molding, the deformation of the layer (2) of the gliding base is particularly involved in the areas of slope failure that are the boundaries of the groove (3). A precise fit and no play at the two elements (10, 11) constituting the gliding base allows maintaining a seal of this layer despite the high mechanical stresses. This seal can be improved by the presence of a film designed for this purpose.

Of course, the invention is not limited to only one embodiment, and can instead be adapted to various manufacturing processes, whether it be molding to assemble pre-existing elements, or else by an in-situ injection to make the core during molding.

In the same way, the invention also makes it possible to use various types of reinforcement in the lower part of the structure, and more specifically in direct contact with the gliding sole.

Thus, as illustrated in figure 6 these reinforcements (40) may be based on fibers impregnated with a polymerizing resin during the molding operation, or during the injection of the nucleus in-situ . This reinforcement thus marries the shape of the groove (3) conforming to the upper surface of the gliding sole (2). This reinforcement may also consist of a metal sheet (42), as illustrated in FIG. figure 7 . In this case, to keep this sheet closest to the gliding base, and therefore furthest away from the neutral fiber, a central opening (43) is provided in which may deform the gliding sole (2) during molding, without causing the movement of the sheet (42).

After molding, the ski has a gliding sole (2) particularly smooth, the surface condition is not really suitable for sliding. In this case, it is necessary to create a slightly rough surface condition by passing over a grinding wheel. This step also makes it possible to eliminate any irregularities and in particular resin infiltrations that could have occurred between the characteristic elements (10, 11) of the gliding base (2).

As already mentioned, the groove being inaccessible to a cylindrical grinding wheel, it is advantageous to use as a central element of the glide sole a pre-structured material, having a suitable surface condition, similar to that of the remainder of the sole after passing through. the grinding wheel.

Of course, the invention applies not only to alpine skis as illustrated in the figures, but to all kinds of gliding boards which have grooves dug in their gliding sole.

It follows from the above that such boards have the advantage of having stabilizing grooves that are quickly identifiable and highlighted by a different color from the rest of the sole.

Claims (9)

Gliding board (1) having a lower layer (2) forming the sliding sole which comprises at least one groove (3) oriented substantially parallel to the sliding direction (4), and forming a depression with respect to the substantially plane remainder of the gliding sole, characterized in that the layer forming the glide sole has a fraction (11) whose shape corresponds at least partially to that of the groove (3), and which is made of a material distinct from the material of which is formed the remainder (10) of the lower layer. Gliding board according to claim 1, characterized in that the materials have different mechanical properties, in particular their coefficient of sliding on the snow. Gliding board according to Claim 1, characterized in that the materials have different colors. Gliding board according to claim 1, characterized in that the fraction (11) of the glide base (2) at the groove (3) has a structured surface condition. Gliding board according to claim 1, characterized in that the groove has a width and / or a variable depth depending on the length of the board. Gliding board according to claim 1, characterized in that it comprises a plurality of grooves, aligned or not. Gliding board according to claim 1, characterized in that it comprises a reinforcing element (30, 40, 42) situated above the gliding base. Gliding board according to claim 1, characterized in that it comprises a sealing film (15) covering the boundary zone of the different fractions (10, 11) of the layer forming the gliding sole. Gliding board according to claim 1, characterized in that the groove has at least locally a depth greater than the thickness of the layer forming the gliding sole.

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