Tongue for a ski boot

Abstract

Tibial tongue (33) for ski boot (1), characterized in that it comprises a foam padding layer (334) having an inner 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 or outer face of the padding layer (334) comprising a raised structure.

Description

Technical field of the invention

[0001] The invention relates to a liner for a ski boot comprising a tibial tongue. The invention also relates to a ski boot comprising such a liner. Prior art

[0002] Alpine skiing is a sport in which a skier guides a pair of skis attached to their feet across snow-covered terrain. During alpine skiing, variations in the terrain are felt through the feet and lower legs via ski boots. Ski boots play a crucial role in the skier's perception of the terrain and in the impulses they transmit to their skis.

[0003] In particular, when a skier links turns, they alternate between flexing and extending their legs. For good ski control, the skier must maintain shin support on their boots. Ski boots require specific characteristics such as support, elasticity, cushioning, and rebound to achieve dynamic, precise, and effortless ski guidance. Furthermore, ski boots must be comfortable, lightweight, and durable. They must also protect the user's feet from cold and moisture while maintaining their properties in low temperatures. Finally, they must be easy to use and manufacture. Current ski boots do not meet all these requirements simultaneously. In particular, they do not allow for sufficiently dynamic, efficient, and precise ski guidance.

[0004] DE 69404408 T2 refers to a part of a shoe, excluding the sole, in particular to a tongue of an inner shoe for a ski boot, consisting essentially of an outer part of semi-rigid and dense plastic material, foam padding and a woven or knitted lining. Presentation of the invention

[0005] The object of the invention is to provide a ski boot liner that remedies the above disadvantages and improves upon known prior art ski boots.

[0006] More specifically, a first object of the invention is a ski boot comprising a tongue for ski boot offering optimal rebound characteristics thus allowing more dynamic, efficient and precise control of the ski fixed to the ski boot. Summary of the invention

[0007] The invention is described in the attached set of claims.

[0008] Convex surfaces can be portions of spheres.

[0009] The reliefs of the relief structure can have dimensions such that they are visible to the naked eye.

[0010] The particles can be made of expanded polyurethane.

[0011] These particles may have a diameter between 2mm and 10mm inclusive, preferably between 3mm and 8mm inclusive.

[0012] The tongue may include an outer layer, the outer face of the padding layer being positioned opposite an inner face of the outer layer, the outer layer being more rigid than the padding layer.

[0013] The tongue may include an air cushion sandwiched between the outer layer and the padding layer.

[0014] The outer layer can be attached to the padding layer by means of a seam.

[0015] The tongue may include a comfort layer forming an inner layer of the tongue, the comfort layer comprising an outer face positioned opposite an inner face of the padding layer.

[0016] The tongue may include a lower part intended to cover the top of a foot and an upper part intended to extend to the front of a lower leg, with the padding layer extending into the upper part.

[0017] The lower part of the tongue may include a thermoformable layer. Presentation of the figures

[0018] These objects, features and advantages of the present invention will be described in detail in the following description of a particular embodiment, given by way of non-limiting example, with reference to the accompanying figures, among which: [ Fig. 1 ] There figure 1 is a side view of a ski boot according to one embodiment of the invention. Fig. 2] There figure 2 is a front view of a ski boot liner according to the embodiment of the invention. Fig. 3 ] There figure 3 is a front view of a tibial tongue of the boot of the figure 2 . [ Fig. 4 ] There figure 4 is a partial front view of the tongue of the slipper of the figure 2 . [ Fig. 5 ] There figure 5 is a partial side view of a layer of padding on the tongue of the slipper of the figure 2 . [ Fig. 6 ] There figure 6 is a schematic cross-sectional view of the tongue of the slipper of the figure 2 . Detailed description

[0019] There figure 1 The diagram schematically illustrates an alpine ski boot 1 according to an embodiment of the invention. The boot 1 comprises a shell 2 and a liner 3 inserted into the shell.

[0020] Shoe 1 is assumed to rest on a horizontal surface. The terms "low" and "high" or "lower" and "upper" refer to a vertical axis. The front and back are defined so that the front of the foot corresponds to the toe area and the back of the foot to the heel area. The terms "inner" and "outer" refer respectively to an orientation towards the inside of the shoe (i.e., towards the foot or leg) and towards the outside of the shoe.

[0021] The shell 2 is a rigid structure surrounding the liner 3. It can be made of plastic, for example. It generally comprises a lower shell 21 designed to enclose the user's foot and a cuff 22 designed to enclose the user's lower leg, that is, the lower part of the user's tibia and calf. The ski boot can thus enclose the foot and approximately one-third, or even one-half, of the lower leg. The cuff 22 is pivotally articulated relative to the lower shell 21 around a transverse axis of rotation 23 extending approximately at the level of the user's malleoli. The forward rotation of the cuff can be limited by resting the cuff 22 against the lower shell 21. To facilitate opening the boot for putting on the ski boot, the cuff may also include lateral flaps that can be spread apart when inserting the foot.The lower shell 21 further includes interfaces 24A, 24B at the front and rear of the boot, designed to cooperate with a fastening device to securely attach 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 with Velcro).

[0022] The liner 3 is a component of the boot designed to be inserted between the shell 2 on one side and the user's foot and lower leg on the other. The liner is generally less rigid than the shell. It provides comfortable support for the foot and lower leg inside the shell. It also transmits the user's impulses to the shell, which is itself fixed to the ski via the binding system. The liner can be removable from the shell, as in the embodiment shown. Alternatively, it could be permanently fixed to the shell, or even integrated into it.

[0023] Slipper 3 is more specifically illustrated on the figure 2It comprises a lower part 31 designed to encircle the foot and an upper part 32 designed to encircle the lower leg of a user. The lower part of the liner extends inside the lower shell 21, and the upper part of the liner extends inside the cuff 22. The upper part 32 of the liner includes two lateral flaps 321, 322 that define a front opening. The liner also includes a tibial tongue 33. The tongue 33 extends at the front of the liner, at the level of the front opening defined by the lateral flaps 321, 322 of the liner. The lateral flaps 321, 322 of the liner may at least partially cover the tongue 33 on its outer surface. The tongue 33 of the liner can come into contact with both the side flaps of the liner and the cuff of the shell. Advantageously, the tongue can even come into direct contact with the cuff 22 of the shell.

[0024] The tongue 33 is called the "tibial" tongue because it is designed to rest on at least part of the user's shin, that is, the front part of the lower leg. Like the bootie, the tongue comprises a rigid upper section 33H, designed to transmit force, and a more flexible lower section 33B, ensuring user comfort. The upper section 33H extends approximately vertically from the lower leg, specifically the shin, to the instep, while the lower section extends from the instep to approximately the base of the toes.

[0025] The tongue 33 is attached to the rest of the slipper 3 at a lower edge 34 of the tongue 33. Specifically, the tongue 33 can be attached all around its lower portion 33B. It can therefore be pivoted forward by a rotational movement at a joint 37 between its upper portion 33H and its lower portion 33B, approximately at the instep. This enlarges the opening 35 through which the foot is inserted into the slipper, making it easier to put on and take off the slipper and thus the shoe.

[0026] Alternatively, the tongue could be attached differently to the rest of the shoe, for example, via a lateral edge of the tongue. The tongue 33 could even be connected to the rest of the shoe via its two lateral edges, to the left and / or right of the tongue. In this case, the shoe would advantageously have sufficient elasticity to enlarge the opening 35 and thus allow the foot to be inserted into the shoe.

[0027] Finally, as an option, the slipper may have a handle 36, for example made of fabric, fixed to the upper part of the tongue, to facilitate handling of the slipper, but also to enlarge the opening for inserting the foot when putting it on.

[0028] As seen on the figure 3The upper part 33H of the tongue 33 may be in the form of an element designed to extend only opposite the lower leg of the user. The upper part 33H may then include 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 tongue.

[0029] Advantageously, any part of the slipper can include a layer made of a thermoformable material, that is, a material that can be deformed by heating. Thus, through a dedicated heating process, the slipper can be molded and adapted to perfectly fit the shape of the foot.

[0030] There figure 6This illustrates a cross-sectional view of the upper part 33H of the tongue 33. Reference 331 indicates an external face of the tongue, that is, a face facing the collar 22 of the shell 2, or more directly towards the outside of the shoe. Reference 332 indicates an internal face of the tongue, that is, a face facing the bottom of the user's leg. The tongue 33 comprises several layers within its thickness. Specifically, considering the different layers of the tongue from the inside out, it includes a comfort layer 333, an intermediate padding layer 334, and an outer layer 335.

[0031] An air cushion 336 can be inserted between the padding layer 334 and the outer layer 335. This air cushion can be reduced or even disappear, particularly 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 primarily from the fact that the padding layer 334 is not fixed, for example, glued to the outer layer 335 over its entire surface. Similarly, the padding layer 334 could also be left unfixed to the comfort layer 333.

[0032] The comfort layer 333 can be, for example, a simple layer of fabric. The comfort layer can be chosen, for example, for its softness and / or its ability to reduce friction with the user's foot or lower leg.

[0033] The outer layer 335 is designed to come into contact with an inner face of the cuff, or even the lower part of the shell. Specifically, the outer layer 335 is designed to come into contact with the inner face of the cuff 22 of the shell 2 or its flaps, or even possibly the flaps of the liner. The outer layer 335 is stiffer than the padding layer 334. The outer layer can, for example, be made of plastic. It may include a transparent area to make the underlying padding layer at least partially visible. The stiffer outer layer plays an important role in transmitting forces from the foot and leg to the boot shell, and then to the ski.

[0034] According to simplified versions of the invention, the tongue might 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 leg) could then rest directly against the padding layer 334. In the absence of an outer layer, the padding layer could rest directly against the collar 22 of the shell 2. According to other embodiments, the tongue could include further layers superimposed on layers 333, 334, and 335.

[0035] The padding layer 334 provides good support and stability for the foot within the liner and shell 2 of the boot. It also acts as an intermediary in transmitting forces from the foot to the outer shell and is designed 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 be, for example, a point seam, formed by one or more stitches distributed at specific locations, such as the top or bottom, and on at least one side of the tongue. The seam could also extend along the perimeter of the padding layer. This attachment aims to ensure proper positioning of the padding layer within the tongue and to prevent it from sagging over time or shifting, for example, when putting the boot on.Alternatively, one or more dots of glue might be sufficient to ensure the correct positioning of the padding layer within the thickness of the tongue.

[0036] To give the shoe its rebound characteristics, an outer face 3341 and an inner face 3342 of the cushioning layer each include a raised structure. Alternatively, this raised structure could be provided on only one of the two faces 3341, 3342. As appears on the figures 3 to 6 The relief structure 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 various convex surfaces 3343 meet at junction lines 3344. These junction lines thus form the hollows of the relief structure, while central areas of each of the convex surfaces form the prominences of the relief structure.

[0037] The raised areas 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 composing the relief structure may be between 0.5 mm and 15 mm inclusive, in particular between 2 mm and 10 mm inclusive, and preferably between 3 mm and 8 mm inclusive. This dimension may be measured along the convex surface in question, between two lines of junction delimiting the convex surface. The difference in depth between the hollows and protrusions of the relief structure may be, for example, on the order of a millimeter, preferably greater than or equal to 0.5 millimeters.

[0038] The padding layer 334 is a foam layer, that is, a layer made of a material whose solid component contains a large number of small, regularly spaced cavities. These cavities, which are preferably closed, can be filled with air or a gas. In particular, the padding layer can be a layer of expanded material.

[0039] The solid material forming the foam can be a synthetic material, in particular a plastic. According to a preferred embodiment of the invention, the padding layer can be made of expanded polyurethane. Such a material offers numerous advantages: it has a low density, is abrasion-resistant, highly elastic, and very resilient. It also has the advantage of maintaining stable mechanical properties at low temperatures, i.e., at the temperatures to which ski boots are subjected. Alternatively, the padding layer could also be made of another thermoplastic foam, such as expanded polyolefin or expanded polyamide.

[0040] Advantageously, the padding layer has a rebound measured according to DIN 53512 of at least 50%, in particular at least 60%, and preferably at least 70%. This measurement makes it possible to determine the rebound of a pendulum on a test specimen made of the padding layer material. Thus, the higher the rebound of the padding layer, the more energy it is able to return during compression. The energy required to flex the ski boots forward can therefore be returned with minimal loss by the padding layer of the invention.

[0041] The padding layer is elastic enough that the raised areas on its surface flatten under the compressive force generated by the user's leg. Therefore, when the shin presses against the tongue, and specifically against the padding layer, each convex surface deforms and compresses. The padding layer can then return to its original shape without permanent deformation once the compression is released. The compressed convex surfaces then regain their initial form.

[0042] A relief structure such as the one described above is obtained by forming the padding layer through the agglomeration of a set of particles. Each convex surface 3343 then corresponds to a particle. These particles may initially be spherical or ovoid in shape. They have a diameter close to that of the convex surfaces 3343, that is, between 0.5 mm and 15 mm inclusive, specifically between 2 mm and 10 mm inclusive, and preferably between 3 mm and 8 mm inclusive. Note that the diameter of a non-spherical particle should be understood as the largest dimension of that particle.

[0043] The particles can be injected under atmospheric pressure into a mold that holds the final shape of the padding layer. The particles can then be pressurized and compressed. This step influences the density and strength of the final expanded foam. The diameter of the particles decreases as pressure is applied. Therefore, at higher pressures, the particles are compressed and densified more strongly. Conversely, if the pressure inside the mold is reduced, the expanded polymer particles essentially return to their original diameters.

[0044] The particles can be partially fused together through a heating step and the application of a temperature for a sufficient duration during the molding of the padding layer. The surface of the particles is then at least partially melted. This allows the particles to chemically bond to one another, thus forming a plastic foam structure.

[0045] When a layer of padding is observed in cross-section, the individual particles may still be distinguishable. In other words, the particles used to manufacture the padding layer may not be completely fused. The resulting padding layer is indeed a monolithic structure; however, its behavior retains, at least in part, mechanical properties resulting from an assembly of unbonded particles.

[0046] Furthermore, another advantage of using expanded particles is that these particles can be bonded together in a random arrangement. Therefore, the particles do not need to be aligned or oriented in a specific way during manufacturing to provide the beneficial effects described here.

[0047] According to one embodiment, it is possible to load the mold with a first material that does not contain expanded particles. The expanded particles, subsequently injected into the mold, can then bond to this first material without requiring an additional bonding step.

[0048] As a note, it is possible to subsequently combine, for example by sewing or gluing, the expanded particle foam, here expanded polyurethane particles, with one or more other foams, of equivalent or any nature, possibly thermoformable, to form the padding layer of the tongue.

[0049] When the user uses the boots 1 for alpine skiing, they alternate between flexing and extending their legs. During the flexion phases, the leg, and in particular the shin, presses against the tongue 33. The cuff 22 tilts forward and comes to rest against the bottom of the shell 21. The tongue 33 of the liner is then compressed between the user's shin and the cuff 22. If necessary, the compression of the air cushion 336 can generate an initial phase of cushioning, and the compression of the padding layer 334 can generate a second phase of cushioning for the leg flexion movement. The ridges formed on the outer face 3341 of the padding layer come into contact with the outer layer 335 of the tongue, and the ridges formed on the inner face 3342 of the padding layer come into contact with the user's shin (possibly via the comfort layer 333).As these raised areas are compressed, they flatten. The expanded particle foam is compressed. During the extension phases, the collar 22 straightens backward. The raised areas expand elastically. This expansion creates a force that helps the collar straighten. The user feels a rebound effect that accompanies their movement. This allows them to guide their skis with precision and less effort.

[0050] 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 shin, a relative sliding between these surfaces can occur. Advantageously, the convex shape of the surfaces 3343 allows for frictionless and snag-free sliding between these surfaces.

[0051] According to an alternative embodiment not in accordance with the claimed invention, a padding layer as previously described could be integrated into the shell 2 of the shoe, in particular into an inner face of a part of the collar 22 extending opposite the tibia, such as for example into an inner face of a lateral flap of the collar 22.

[0052] According to yet another embodiment not conforming to the claimed invention, a padding layer as previously described could be integrated into a rear portion of the shoe or slipper, substantially opposite a lower part of the calf. Positioned in this way, the padding layer would also contribute to improving cushioning and rebound.

Claims

1. Liner (3) for a ski boot, comprising a lower portion (31) intended to surround the foot, an upper portion (32) intended to surround the lower leg of a user, the upper portion comprising two lateral flaps (321, 322) defining a front opening, the liner comprising a tibial tongue (33) extending at the front of the liner at the level of the front opening, the tibial tongue comprising a foam padding layer (334) having an inner face (3342) intended to extend opposite a front part of the lower leg and an outer face (3341) opposite the inner face, characterized in that at least one of the inner face or the outer face of the padding layer (334) comprises a relief structure, the relief structure being formed by a juxtaposition of convex surfaces (3343), the padding layer (334) comprising a set of particles at least partially fused together, each convex surface corresponding to one particle, said particles having a diameter comprised between 0.5 mm and 15 mm inclusive.

2. Liner (3) according to the preceding claim, characterized in that the convex surfaces (3343) are portions of spheres.

3. Liner (3) according to any one of the preceding claims, characterized in that the reliefs of the relief structure are of such dimensions that they are visible to the naked eye.

4. Liner (3) according to any one of the preceding claims, characterized in that the particles are made of expanded polyurethane.

5. Liner (3) according to any one of the preceding claims, characterized in that said particles have a diameter comprised between 2 mm and 10 mm inclusive, preferably between 3 mm and 8 mm inclusive.

6. Liner (3) according to any one of the preceding claims, characterized in that the tongue (33) 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 more rigid than the padding layer (334).

7. Liner (3) according to the preceding claim, characterized in that the tongue (33) comprises an air cushion (336) interposed between the outer layer (335) and the padding layer (334).

8. Liner (3) according to any one of claims 6 or 7, characterized in that the outer layer (335) is attached to the padding layer (334) by means of stitching.

9. Liner (3) according to any one of the preceding claims, characterized in that the tongue (33) comprises a comfort layer (333) forming an inner layer of the tongue, the comfort layer having an outer face positioned opposite the inner face (3342) of the padding layer (334).

10. Liner (3) according to any one of the preceding claims, characterized in that the tongue (33) comprises a lower part (33B) intended to cover the top of a foot and an upper part (33H) intended to extend in front of the lower leg, the padding layer (334) extending in the upper part.

11. Liner (3) according to the preceding claim, characterized in that the lower part (33B) of the tongue comprises a thermoformable layer.

12. Ski boot (1), characterized in that it comprises a liner (3) according to any one of the preceding claims and a shell (2), the liner being inserted in the shell.

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