EP4000443A1 - Tongue for a ski boot - Google Patents

Abstract

Tibial tongue (33) for a ski boot (1), characterized in that it comprises a foam padding layer (334) having an internal face (3342) intended to extend opposite a front part of the lower leg and an outer face (3341) opposite the inner face, at least one of the inner face or the outer face of the padding layer (334) comprising a relief structure.

Description

Technical field of the invention

The invention relates to a tibial tongue for a ski boot. The invention also relates to a liner for a ski boot comprising such a tibial tongue. The invention finally relates to a ski boot comprising such a liner and/or such a tibial tongue.

State of the prior art

Alpine skiing is a sport in which a user guides a pair of skis attached to their feet over snowy terrain. When practicing alpine skiing, variations in the terrain are felt in the feet and lower legs through ski boots. Ski boots play an essential role in the user's perception of the terrain and in the impulses he transmits to his skis.

In particular, when a skier links turns, he alternates phases of flexion and extension of the legs. For good control of his skis, the skier must maintain tibial support on his boots. Support but also elasticity, cushioning and rebound characteristics of ski boots are sought in order to obtain guiding of the skis that is dynamic, precise and without superfluous effort. In addition, ski boots should be comfortable, light and strong. They must also protect the user's feet against cold and humidity while retaining their properties at low temperatures. Finally, they must also be simple to use and manufacture. The known ski boots of the state of the art do not make it possible to achieve all of these requirements at the same time. In particular, shoes known to the state of the technique do not allow the skis to be guided in a sufficiently dynamic, efficient and precise manner.

Presentation of the invention

The object of the invention is to provide a tongue for a ski boot remedying the above drawbacks and improving the ski boots known from the prior art.

More specifically, a first object of the invention is a tongue for a ski boot offering optimal rebound characteristics, thus allowing more dynamic, efficient and precise control of the ski attached to the ski boot.

A second object of the invention is a tongue for a comfortable ski boot, offering both good insulation against the cold, retaining its properties at low temperature, resistant and simple to manufacture.

Summary of the invention

The invention relates to a tibial tongue for a ski boot, the tongue comprising a layer of foam padding having an internal face intended to extend opposite a front part of the bottom of a leg and an outer face opposite the inner face, at least one of the inner face or the outer face of the padding layer comprising a relief structure.

The relief structure can be formed by a juxtaposition of convex surfaces.

The convex surfaces can be portions of spheres.

The reliefs of the relief structure can have dimensions such that they are visible to the naked eye.

The padding layer may comprise a set of particles at least partially fused together.

The particles can be made of expanded polyurethane.

Said particles may comprise a diameter of between 0.5mm and 15mm inclusive, in particular between 2mm and 10mm inclusive, preferably between 3mm and 8mm inclusive.

The tongue may comprise an outer layer, the outer face of the padding layer being positioned facing an inner face of the outer layer, the outer layer being more rigid than the padding layer.

The tongue may include an air cushion sandwiched between the outer layer and the padding layer.

The outer layer can be attached to the padding layer by means of a seam.

The tongue may comprise a comfort layer forming an internal layer of the tongue, the comfort layer comprising an external face positioned opposite an internal face of the padding layer.

The tongue may comprise a lower part intended to cover the top of a foot and an upper part intended to extend to the front of the bottom of a leg, the padding layer extending in the upper part.

The lower part of the tongue can comprise a thermoformable layer.

The invention also relates to a ski boot liner comprising a tongue as defined previously.

The invention also relates to a ski boot comprising a liner as defined above and a shell, the liner being inserted into the shell, and/or comprising a tongue as defined above.

Presentation of figures

• [Fig. 1] La figure 1 est une vue de côté d'une chaussure de ski selon un mode de réalisation de l'invention.
• [Fig. 2] La figure 2 est une vue de face d'un chausson de la chaussure de ski selon le mode de réalisation de l'invention.
• [Fig. 3] La figure 3 est une vue de face d'une languette tibiale du chausson de la figure 2.
• [Fig. 4] La figure 4 est une vue partielle de face de la languette du chausson de la figure 2.
• [Fig. 5] La figure 5 est une vue partielle de côté d'une couche de rembourrage de la languette du chausson de la figure 2.
• [Fig. 6] La figure 6 est une vue schématique en coupe de la languette du chausson de la figure 2.

These objects, characteristics and advantages of the present invention will be explained in detail in the following description of a particular embodiment given on a non-limiting basis in relation to the attached figures, among which:

• [ Fig. 1 ] The figure 1 is a side view of a ski boot according to one embodiment of the invention.
• [ Fig. 2 ] The picture 2 is a front view of a liner of the ski boot according to the embodiment of the invention.
• [ Fig. 3 ] The picture 3 is a front view of a tibial tab of the bootie of the picture 2 .
• [ Fig. 4 ] The figure 4 is a partial front view of the tongue of the liner of the figure 2 .
• [ Fig. 5 ] The figure 5 is a partial side view of a layer of liner tongue padding from the figure 2 .
• [ Fig. 6 ] The figure 6 is a schematic sectional view of the tongue of the liner of the figure 2 .

detailed description

The figure 1 schematically illustrates an alpine ski boot 1 according to one embodiment of the invention. Shoe 1 comprises a shell 2 and an inner boot 3 inserted into the shell.

It is considered that the shoe 1 rests on a horizontal ground. The terms "bottom" and "top" or "lower" and "upper" refer to a vertical axis. The front and rear are defined so that the front of the foot corresponds to the toe area and the rear of the foot corresponds to the heel area. The terms “internal” and “external” refer respectively to an orientation towards the inside of the shoe (that is to say towards the foot or the leg), and towards the outside of the shoe.

The shell 2 is a rigid structure surrounding the liner 3. It may for example be made of plastic material. It generally comprises a lower shell 21 intended to wrap a foot of a user and a collar 22 intended to wrap a lower leg of the user, that is to say a lower part of the tibia and the calf of the user. The ski boot can thus envelop the foot and substantially a lower third of the lower leg, or even a lower half of the lower leg. The collar 22 is articulated in rotation with respect to the bottom of the shell 21 around a transverse axis of rotation 23 extending substantially at the level of the malleolus of the user. The amplitude of rotation of the collar forwards can be limited by resting the collar 22 on the bottom of the shell 21. In order to facilitate its opening for putting on the shoe, the collar can also include side flaps which can be pushed apart when inserting the foot. The bottom of the shell 21 further comprises interfaces 24A, 24B at the front and at the rear of the boot intended to cooperate with a fixing device for solidly fixing the boot to a ski (not shown). Finally, the shell 2 is provided with closure means 25, for example in the form of hooks and/or straps (for example tightened by Velcro).

The liner 3 is an element of the shoe intended to be inserted between the shell 2 on the one hand and the foot and the lower leg of the user on the other hand. The liner is generally less rigid than the shell. It provides comfortable foot and lower leg support functions inside the shell. It also transmits the impulses given by the user to the shell, itself fixed solidly to the ski by means of the fixing device. The liner may be removable relative to the shell, as in the context of the embodiment presented. As a variant, it could be fixed in a non-removable manner in the shell, or even be integrated into it.

Slipper 3 is more precisely illustrated on the picture 2 . It comprises a lower part 31 intended to surround the foot and an upper part 32 intended to surround the lower leg of a user. The lower part of the liner therefore extends inside the bottom of the shell 21 and the upper part of the liner extends inside the collar 22. The upper part 32 of the liner comprises two side flaps 321, 322 which delimit a front opening. The liner further comprises a tibial tongue 33 . The tongue 33 extends at the front of the liner, at the level of the front opening delimited by the side flaps 321, 322 of the liner. The side flaps 321, 322 of the liner can at least partially cover the tongue 33 on its outer face. The tongue 33 of the liner can come into contact both with the side flaps of the liner and with the collar of the shell. Advantageously, the tongue can even come directly into contact with the collar 22 of the shell.

The tab 33 is called "tibial" because it is intended to bear at least on a part of the user's tibia, that is to say a front part of the lower leg. In the same way as the liner, the tongue comprises an upper part 33H, more rigid, intended for the transmission of forces, and a lower part 33B, more flexible, ensuring comfort for the user. The upper part 33H extends substantially vertically vis-à-vis the lower leg, in particular the tibia, up to the instep, while the lower part extends from the instep and up 'at substantially the base of the toes.

The tongue 33 is fixed to the rest of the liner 3 at the level of a lower edge 34 of the tongue 33. In particular, the tongue 33 can be fixed over the entire periphery of its lower part 33B. It can therefore be pivoted forwards by a rotational movement at the level of a connection 37 between its upper part 33H and its lower part 33B, substantially at the level of the instep. This makes it possible to enlarge the opening 35 through which the foot is inserted into the liner, which facilitates putting on and taking off the liner and therefore the shoe.

As a variant, the tongue could be fixed differently to the rest of the liner, in particular by means of a lateral edge of the tongue. The tongue 33 could even be connected to the rest of the liner via its two side edges, to the left and/or right of the tongue. In this case, the liner would advantageously have sufficient elasticity to enlarge the opening 35 and thus allow the insertion of the foot into the liner.

Finally, optionally, the liner may have a handle 36, for example in fabric, fixed in the upper part of the tongue, to facilitate handling of the liner, but also to enlarge the opening for inserting the foot when putting on the shoe.

As seen on the picture 3 , the upper part 33H of the tongue 33 may be in the form of an element intended to extend only vis-à-vis the lower leg of the user. The upper part 33H can then comprise a lower interface in the shape of an inverted U by which it is fixed, in particular sewn, to the lower part 33B of the tab.

Advantageously, any part of the liner may comprise a layer provided with a thermoformable material, that is to say a material deformable by heating. Thus, thanks to a dedicated operation for heating the liner, it can be deformed and adapted to perfectly match the shape of the foot.

The figure 6 illustrates a sectional view of the upper part 33H of the tongue 33. The reference 331 indicates an outer face of the tongue, that is to say a face facing the collar 22 of the shell 2, or more directly towards the exterior of the shoe. The reference 332 indicates an internal face of the tongue, that is to say a face facing the bottom of the user's leg. The tongue 33 comprises different superimposed layers in its thickness. In particular, considering the different layers of the tongue from the inside out, it comprises a comfort layer 333, an intermediate padding layer 334 and an outer layer 335.

An air cushion 336 may be interposed between the padding layer 334 and the outer layer 335. This air cushion may possibly be reduced, or even disappear, in particular when the tongue is compressed according to its thickness. Such an air cushion could also be formed between the padding layer 334 and the comfort layer 333. This air cushion results mainly from the fact that the padding layer 334 is not fixed, for example glued against the layer. external 335 over its entire surface. Similarly, padding layer 334 could also not be secured against comfort layer 333.

The comfort layer 333 may for example be a single layer of fabric. The comfort layer can be chosen, for example, for its characteristics of softness and/or limitation of friction with the user's foot or lower leg.

The outer layer 335 is intended to come into contact with an inner face of the collar, or even of the bottom of the shell. In particular, the outer layer 335 is intended to come into contact with the inner face of the collar 22 of the shell 2 or of its flaps, or possibly even the flaps of the liner. The outer layer 335 is more rigid than the padding layer 334. The outer layer can for example be made of plastic material. It may include a transparent zone so as to make the underlying padding layer visible at least partially. The more rigid outer layer plays an important role in transmitting forces from the foot and leg to the shell of the boot, then to the ski.

According to simplified versions of the invention, the tongue could not include the comfort layer 333 and/or the outer layer 335. In the absence of a comfort layer, the lower leg (or a sock covering the lower the leg) could then bear directly against the padding layer 334. In the absence of an outer layer, the padding layer could bear directly against the collar 22 of the shell 2. According to other variant embodiments, the tongue could still comprise other layers superimposed on the layers 333, 334, 335.

The padding layer 334 is a layer providing good wedging and good support for the foot within the liner and the shell 2 of the shoe. In addition, it also acts as an intermediary in the transmission of forces from the foot to the outer shell, and is intended to give the tongue its rebound properties. The padding layer can be attached to the outer layer 335 by means of a seam. This seam can for example be punctual, and formed by one or more stitches, distributed at specific locations, for example at the top or bottom, and on at least one side of the tongue. The seam could also extend along a periphery of the padding layer. This attachment is intended to ensure proper positioning of the padding layer within the tongue and to prevent it from sagging over time, or from shifting when putting on shoes, for example. As a variant, one or more dots of glue could suffice to guarantee the correct positioning of the padding layer in the thickness of the tongue.

To impart its rebound characteristics to the shoe, an outer face 3341 and an inner face 3342 of the padding layer each comprise a relief structure. As a variant, this structure in relief could only be provided on one of the two faces 3341, 3342. As it appears on the figures 3 to 6 , the structure in relief is formed by a juxtaposition of convex surfaces 3343. These convex surfaces can, for example, be portions of a sphere, or at least curved surfaces. The different convex surfaces 3343 meet at junction lines 3344. These junction lines therefore form the depressions of the structure in relief while the central zones of each of the convex surfaces form the prominences of the structure in relief.

The reliefs formed on the surface of the padding layer are large enough to be visible to the naked eye. For example, with reference to the figure 4 , the largest diameter of each convex surface making up the structure in relief may be between 0.5 mm and 15 mm inclusive, in particular between 2 mm and 10 mm inclusive, preferably between 3 mm and 8 mm inclusive. This dimension can be measured along the convex surface considered, between two joining lines delimiting the convex surface. The difference in depth between the recesses and the prominences of the structure in relief can be for example of the order of a millimeter, preferably greater than or equal to 0.5 millimeter.

The padding layer 334 is a layer of foam, that is to say a layer made of a material whose solid material contains a large number of cavities of small dimensions and regularly distributed. These cavities, which are preferably closed cavities, can be filled with air or with a gas. In particular, the padding layer can be a layer of expanded material.

The solid material forming the foam may be a synthetic material, in particular a plastic material. According to a preferred embodiment of the invention, the padding layer can be made of expanded polyurethane. Such a material offers many advantages: it has a low density, it is resistant to abrasion, it has a high elasticity and it is very resilient. Such a material also has the advantage of retaining stable mechanical properties at low temperature, that is to say at temperatures to which ski boots are subjected. As a variant, the padding layer could also be made with another thermoplastic foam, such as for example an expanded polyolefin or an expanded polyamide.

Advantageously, the padding layer comprises a rebound measured according to the DIN53512 standard at least equal to 50%, in particular at least equal to 60%, preferably at least equal to 70%. This measurement makes it possible to determine the rebound of a pendulum on a test piece made with the material of the padding layer. Thus, the higher the rebound of the padding layer, the more it is able to return the energy absorbed during its compression. The energy needed to flex the ski boots forward can therefore be restored with little loss by the padding layer of the invention.

The padding layer is sufficiently elastic for the reliefs formed on its surface to flatten under the effect of a compression force generated by the leg of the user. Therefore, following a support of the tibia against the tongue and in particular against the padding layer, each convex surface is deformed and compressed. The cushioning layer can then return to its original shape without permanent deformation, when the compression ceases. The compressed convex surfaces then return to their initial shape.

A structure in relief as described above can be obtained by forming the padding layer by an agglomeration of a set of particles. Each convex surface 3343 can then correspond to a particle. These particles may initially have a spherical or ovoid shape. They may have a diameter close to that of the convex surfaces 3343, that is to say between 0.5 mm and 15 mm inclusive, in particular between 2 mm and 10 mm inclusive, preferably between 3 mm and 8 mm inclusive. As a side note, the diameter of a non-spherically shaped particle should be understood as the largest dimension of that particle.

The particles can be injected under atmospheric pressure into a mold having the final shape of the padding layer. The particles can then be pressurized and compressed. This step will influence the density and resistance of the final expanded foam. Thus, the diameter of the particles decreases by means of the application of pressure. So for higher pressures, the particles are compressed and densified more strongly. On the other hand, if the pressure inside the mold is reduced, the expanded polymer particles essentially expand to their original diameters.

The particles can be partially fused together thanks to a heating step and the application of a temperature for a sufficient time during the molding of the padding layer. The surface of the particles is then at least partially melted. Thus, the particles can chemically bond with each other. A plastic foam structure is thus formed.

When looking at a padding layer in cross-section, the individual particles may still be discernible. In other words, the particles used for the manufacture of the padding layer may not be completely fused. The padding layer obtained is indeed a monolithic assembly, however its behavior retains, at least in part, mechanical properties resulting from an assembly of particles not bonded together.

Furthermore, another advantage of the use of expanded particles is that these particles can be bonded together in a random arrangement. The particles thus do not need to be aligned or oriented in any particular way during manufacture to provide the beneficial effects described herein.

According to a variant embodiment, it is possible to load the mold with a first material which does not comprise expanded particles. The expanded particles, subsequently injected into the mold, will be able to bind to this first material, without requiring an additional bonding step.

As a side note, it is possible to subsequently combine, for example by sewing or gluing, the foam of expanded particles, here of expanded polyurethane particles, with one or more other foams, of equivalent or unspecified nature, possibly thermoformable, for forming the tongue padding layer.

When the user uses boots 1 for downhill skiing, he alternates phases of flexion and extension of his legs. During the bending phases, the leg and in particular the tibia, press on the tongue 33. The collar 22 tilts forwards and comes into abutment against the bottom of the shell 21. The tongue 33 of the liner is then compressed between the user's shin and the collar 22. If necessary, the compression of the air cushion 336 can generate a first phase of damping and the compression of the padding layer 334 can generate a second phase of damping of the movement bending of the legs. The reliefs formed on the outer face 3341 of the padding layer come into contact with the outer layer 335 of the tongue, and the reliefs formed on the inner face 3342 of the padding layer come into contact with the user's tibia (possibly via the comfort layer 333). These reliefs being compressed, they flatten out. The foam of expanded particles compresses. During the extension phases, the collar 22 straightens backwards. The reliefs relax elastically. The relaxation of the reliefs creates a force which promotes the straightening of the collar. The user feels a rebound effect that accompanies his movement. He thus manages to guide his skis with precision and less effort.

When the outer face 3341 of the padding layer comes into contact with the outer layer 335 of the tongue and/or when the inner face 3342 of the padding layer comes into contact with the tibia, a relative sliding between these surfaces can occur. Advantageously, the convex shape of the surfaces 3343 allows sliding without friction or hitch between these surfaces.

According to a variant embodiment of the invention, a padding layer as previously described could be integrated into the shell 2 of the shoe, in particular into an internal face of a part of the collar 22 extending opposite of the tibia, such as on an inner face of a side flap of the collar 22.

According to yet another variant embodiment, a padding layer as previously described could be integrated into a rear part of the shoe or liner, substantially opposite a lower part of the calf. Positioned in this way, the padding layer would also help improve cushioning and rebound.

Claims (15)

Tibial tongue (33) for a ski boot (1), characterized in that it comprises a foam padding layer (334) having an internal face (3342) intended to extend opposite a front part of the lower leg and an outer face (3341) opposite the inner face, at least one of the inner face or the outer face of the padding layer (334) comprising a relief structure. Tongue (33) according to the preceding claim, characterized in that the structure in relief is formed by a juxtaposition of convex surfaces (3343). Tongue (33) according to the preceding claim, characterized in that the convex surfaces (3343) are portions of spheres. Tongue (33) according to one of the preceding claims, characterized in that the reliefs of the structure in relief have dimensions such that they are visible to the naked eye. Tongue (33) according to one of the preceding claims, characterized in that the padding layer (334) comprises a set of particles at least partially fused together. Tongue (33) according to the preceding claim, characterized in that the particles are made of expanded polyurethane. Tongue (33) according to one of Claims 5 or 6, characterized in that the said particles comprise a diameter between 0.5mm and 15mm inclusive, in particular between 2mm and 10mm inclusive, preferably between 3mm and 8mm inclusive. Tongue (33) according to one of the preceding claims, characterized in that it comprises an outer layer (335), the outer face (3341) of the padding layer being positioned opposite an inner face of the outer layer, the outer layer (335) being stiffer than the padding layer (334). Tongue (33) according to the preceding claim, characterized in that the tongue (33) comprises an air cushion (336) inserted between the outer layer (335) and the padding layer (334). Tongue (33) according to one of Claims 9 or 10, characterized in that the outer layer (335) is fixed to the padding layer (334) by means of a seam. Tongue (33) according to one of the preceding claims, characterized in that it comprises a comfort layer (333) forming an internal layer of the tongue, the comfort layer comprising an outer face positioned opposite the internal face (3342) of the padding layer (334). Tongue (33) according to one of the preceding claims, characterized in that it comprises a lower part (33B) intended to cover the top of a foot and an upper part (33H) intended to extend to the front of a lower leg, the padding layer (334) extending in the upper part. Tongue (33) according to the preceding claim, characterized in that the lower part (33H) of the tongue comprises a layer thermoformable. Liner (3) for a ski boot, characterized in that it comprises a tongue (33) according to one of the preceding claims. Ski boot (1), characterized in that it comprises a liner (3) according to the preceding claim and a shell (2), the liner being inserted into the shell, and/or in that it comprises a tongue one of claims 1 to 13.

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