EP2677891A2

EP2677891A2 - Shoe for practicing sports involving gliding over the snow, or for walking

Info

Publication number: EP2677891A2
Application number: EP12713201.7A
Authority: EP
Inventors: Pierre Gignoux; Franck CONSTANT; Thomas Saillet
Original assignee: Salomon SAS
Current assignee: Salomon SAS
Priority date: 2011-02-21
Filing date: 2012-02-20
Publication date: 2014-01-01
Also published as: RU2013142929A; WO2012114002A3; US20140013630A1; RU2607765C2; FR2971675A1; WO2012114002A2; FR2971675B1

Abstract

The invention relates to a shoe (1) for practicing sports involving gliding over the snow, or for walking, which is characterized in that it includes an outer shell (2, 2', 20, 26, 26', 34, 42) made of a rigid material, the shell (2, 2', 20, 26, 26', 34, 42) including a rear cradle (22, 28, 28', 39, 44) provided to receiver the heel of the user, the rear cradle (22, 28, 28', 39, 44) being extended toward the front by a blade-shaped portion (6) that defines a bending area, the rear cradle (22, 28, 28', 39, 44) comprising a peripheral wall (5, 31) and a bottom, the bottom of the cradle and the blade-shaped portion partially defining the bottom assembly of the shoe, and characterized in that it includes an inner liner (20).

Description

Footwear intended for the practice of a sliding sport on snow, or walking

The invention relates to a shoe intended in particular for the practice of a sport of sliding on snow, or walking. The invention more particularly relates to a shoe adapted to Nordic skiing such as cross-country skiing or ski touring, mountain skiing, ski mountaineering or telemark, that is to say a practice for which a user alternately raises the heel. The invention also relates to a shoe adapted to the practice of walking in the mountains, or mountaineering. The invention further relates to a shell for a sports shoe.

The practice of these activities or an activity such as cross-country skiing requires the use of relatively rigid shoes in torsion, between the front and the back of the shoe, to be able to accurately transmit the actions of the foot to the ski while retaining the flexibility of flexion required to unwind the foot at the metatarsal joint.

As far as cross-country skiing proper is concerned, the relative rigidity that was lacking on the first cross-country ski boots at the time of the appearance of the so-called "skater's step technique" found a technical answer with the use reinforcements, generally composite materials, which are superimposed and connected to the existing structure which is made of synthetic materials and / or thermoplastics. Indeed, cross-country ski boots have traditionally a mounted construction, in which the shoe comprises a flexible rod mounted on a first mounting, the assembly being bonded to an outer sole, and the reinforcing elements being generally attached to the outer sole. outside the rod in addition to reinforcements and buttresses traditionally used.

The shoes produced in this way are stiffer, which allows better control of the ski and balance, but they have also become heavier, since additional reinforcements add to the weight of the shoe, even if they are made with materials. choose the lightest possible.

In a more general manner, the shoes according to the prior art have a shaft and a sole with fairly complex structures, for a high weight. The complexity is the fact of the multitude of elements necessary to manufacture the stem on the one hand, and the sole assembly on the other hand, the stem comprises at least a first envelope which gives the shoe its general appearance, a buttress for the maintenance heel, localized reinforcements added to the first envelope to obtain localized increases in mechanical strength, and a second envelope or lining, housed in the first envelope, to fulfill one or more functions such as comfort, thermal insulation , Or other. The sole assembly comprises at least a first mounting plate, intended to hold together the constituent elements of the rod. The sole includes a step outsole, designed to contact the ground, and a so-called insole, housed in the envelopes. It is noted in passing that the outsole often comprises two or more layers, one for wear, the other for damping. Still about shoes according to the prior art, the complexity of the structure makes the manufacturing complex. It is indeed necessary to group together the constituent elements of the rod, by applying them to a shape, and then maintain them, generally by gluing, on the first assembly. The subassembly thus produced then receives the outsole and the insole. As can be seen, the manufacture is quite complex and, in the end, given the number of constituents, the shoe obtained is quite heavy.

Moreover, a greater or lesser flexural rigidity of the alpine ski or cross-country ski boot is sometimes necessary. Today there is no answer to this constraint and the only solution is to have several shoes according to practice. Take the case of cross-country skiing: you need a pair of flexible shoes in flexion for the practice of the so-called classical technique, and a pair of rigid shoes in flexion for the practice of the technique of skating step. This can be particularly tricky in the case of competitions where there is a combination of two events, a classic event followed immediately by a skater's step without a stopwatch. The shoes used for these types of events are mixed shoes whose rigidity is intermediate between the two types of shoes. It is therefore a compromise not ideal in each of the techniques.

Broadly the invention provides a shoe, intended for the practice of a sport of sliding on snow or walking as evoked before, which has both a good torsional stiffness, good flexibility in flexion, and a weight reduced. By corollary the invention seeks to reduce the fatigue of the user, or to help improve its performance.

One of the aims of the present invention is therefore to overcome the drawbacks of the state of the art by providing a Nordic ski boot having both good torsional stiffness, good flexibility in flexion and reduced weight, while satisfying to the conditions of comfort.

An object of the invention is also to provide a modular shoe whose rigidity is adjustable according to practice.

To do this, the invention proposes a shoe intended in particular for the practice of a sport of sliding on snow or walking. The shoe according to the invention is characterized in that it comprises an outer shell of rigid material, the shell comprising a rear cradle designed to contain the heel of the user, the rear cradle being extended forward by a part blade-shaped defining a flexion zone, the rear cradle having a peripheral wall and a bottom, the bottom of the cradle and the blade-shaped portion partly defining the sole of the shoe, and characterized by the fact that it comprises an inner bootie.

The shell includes the rear cradle and the blade-shaped portion and, as such, the shoe has good torsional rigidity and flexural flexibility. The slipper placed in the shell gives the shoe the minimum comfort of use. It can be said that the invention dissociates the elements of the shoe according to the function they must fulfill, that is to say either a function of transmitting sensory information or transmission of driving pulses, by the rigidity in torsion or flexibility in bending of the hull, that is a function of comfort, holding and / or wrapping of the foot, by the disposition of the liner in the hull. The dissociation of the elements of the shoe simplifies the structure, compared to a shoe with shaft mounted according to the prior art. The dissociation of the elements also makes it possible to optimize the structure, or the function. In the invention, by putting a single material at the necessary place, and thus avoiding multiplying layer overlays, the shoe obtained comprises a reduced number of pieces. The dissociation of the functions makes it possible to optimize each element, especially reinforcement, and thus to reduce the weight as much as possible. This amounts to saying that the structure created by the invention lightens the shoe. A resulting technical effect is a reduction of its mechanical inertia, compared to a shoe according to the prior art. In summary, it can be said that one advantage of the shoe of the invention is to reduce the fatigue of a user or, by corollary, to increase its performance, while retaining the qualities of the shoes of the prior art, in particular torsional rigidity and flexibility in flexion.

Paradoxically, the shoe according to the invention has managed to reconcile two antinomic characteristics, which are on the one hand the precision of driving or taking supports and, on the other hand, comfort, while lowering the weight of the shoe. Indeed the shell of rigid material, despite its torsional and flexural characteristics, also provides a certain comfort. For example, for a cross-country ski boot, the outer shell stiffens the boot, but this shell has thicknesses sufficiently thin to fit the foot and provide a precise wrap of it. This paradoxically contributes to making the shoe comfortable, despite the use of rigid materials.

According to one or more other characteristics of the shoe, taken alone or in combination,

the thickness of the peripheral wall of the rear cradle is less than 5 millimeters

the thickness of the peripheral wall of the front cradle is less than 5 millimeters,

the hull comprises a front cradle, the blade-shaped portion connecting the rear cradle to the front cradle, the blade-shaped portion extending at the metatarsal level of a user, a recess being located between the rear cradle and the cradle; front cradle at the blade-shaped portion,

the rear cradle and the blade-shaped part are monobloc,

the rear cradle and the blade-shaped part are distinct elements,

the thickness of the blade-shaped portion in the bending zone is less than 4 millimeters,

- Between the bottom and the upper opening, the thickness of the peripheral wall thins,

- the minimum width of a recess of the bending zone is at least greater than 5 millimeters,

the minimum width of a recess of the bending zone is between 20 and 30 millimeters and is preferably of the order of 25 millimeters,

the shell is made entirely of composite materials and the thickness of the peripheral wall is between 0.5 and 1.2 millimeters,

the shell is entirely made of carbon fibers and the thickness of the peripheral wall is between 0.5 and 0.8 millimeters, at least the peripheral wall is made of glass fibers and the thickness of said peripheral wall is between 0.8 and 2 millimeters,

the blade-shaped part is made of composite materials and comprises fibers of the unidirectional composite material in the bending zone,

the flexion zone defines a front cradle and a rear cradle, the materials of the front and rear cradles being different from one another, the blade-shaped part being made of carbon fibers,

- lightening holes are made in the rear cradle,

- at least one cradle is made of plastic material and the thickness of the cradle is less than or equal to 1.5 millimeters,

the bending zone of the blade-shaped part is thicker than the rest of the blade-shaped part,

the flexion zone comprises fibers which form an angle with the longitudinal axis of the shoe,

the flexion zone defines a front cradle and a rear cradle, the hull comprising the front cradle and the rear cradle, the hull comprising means for fixing the front and rear cradles at an overlap of the front and rear bottoms of the cradles; ,

the bottom of the rear cradle extends under the bottom of the front cradle, the fixing means being arranged under the front cradle,

the front bottom extends under the rear bottom, the fixing means being arranged under the rear cradle,

the fixing means is removable,

- the hull is monobloc,

- The shell comprises a stiffening blade extending at least under the bending zone, said stiffening blade being adapted to take an active position in which said stiffening blade thickens the sole assembly in the bending zone, and an inactive position in which end of the stiffening blade is free,

the free end of the stiffening blade extends towards the rear of the flexion zone,

- The free end of the stiffening blade is adapted to be retained in the active position by a removable retaining means,

- The shell has lateral amounts of protection at the malleolus,

the flexion zone defines a front cradle and a rear cradle, and the front cradle has an upper central notch,

- The shell has through holes adapted to receive fixing screws, and it has internal shoulders arranged around the through holes, adapted to house the heads of said fixing screws.

In connection with the stiffening blade, it is specified that the shoe according to the invention overcomes the disadvantage of the lack of adjustment of the flexural stiffness, by proposing an adjustable stiffness depending on the type of practice. So the same shoe can be flexible in bending in one case, and rigid bending in another simply by activating a connection between the shell and an auxiliary blade.

The shell therefore comprises a blade superimposed on the sole assembly and secured thereto in front of the flexion zone, but independent of it beneath the flexion zone and behind it. The first function of this blade is to stiffen the hull in reverse bending, that is to say when the foot goes back and the front of the shoe is maintained on the ski for example. This is particularly useful for a mountain ski boot that will tend to bend upside down when pressing on the upper part of the shoe. The shoe without this blade could then break simply on a back support.

The second function of this blade is to stiffen the hull flexion when it is coupled to the hull. One thus obtains with the same shell, a soft shoe in one case and rigid in the other.

The invention also relates to a shell intended to be part of a shoe as evoked before.

According to a first exemplary embodiment, the flexion zone defines a front cradle and a rear cradle in the shell and the shoe has two straight struts respectively connecting the walls of the rear cradle with the walls of the front cradle.

According to another exemplary embodiment, the flexion zone defines a front cradle and a rear cradle in the shell, and the shoe comprises a guy having a "Y" shape connecting the walls of the rear cradle with the front cradle.

The flexion zone allows the ski boot to be flexibly flexed at the metatarsal articulation to allow the foot to unwind during the practice of skiing. The thickness of the peripheral wall of the cradle at most less than 1.5 millimeters makes it possible to obtain a ski boot which has the required qualities of both rigidity and low weight.

The cradles are very thin on the lateral and medial parts, which gives a certain flexibility, useful for comfort and necessary to tighten the foot without weighing down the hull. In addition, the cradle forms of the hull give it great rigidity at the front and rear.

Thanks to the composite materials, excellent rigidity and low weight can be obtained with a thickness of the lateral and medial very thin, between 0.5 and 1, 2 millimeters. It is thus possible to obtain ski boots weighing about 300g per foot instead of 600g to 700g for a shoe of the state of the art.

Moreover, with a thickness of the blade-shaped part in the flexion zone at most less than 4 millimeters, the flexion is comfortable at the metatarsal joint.

Thus, with a thickness of the peripheral wall of the cradle less than 1.5 millimeters and a bending zone formed by recesses between the cradles, the shell has good torsional rigidity while having good bending flexibility and controlled weight. . The geometry and the choice of the materials of the shell make it possible to obtain a shoe having a good torsional rigidity and a good flexibility in flexion, and which is comfortable.

Furthermore, the use of a stiffening blade allows in reverse bending, the stiffening blade rigidifies the sole assembly in the active position and prevents this reverse bending of the hull. This is particularly useful for a mountain ski boot that will tend to bend upside down when pressing on the collar of the shoe. A hull devoid of this blade could risk breaking simply on a back support.

Thus, the same shoe can be used for different Nordic skiing practices. The stiffening blade is deactivated to obtain a flexible flexural shoe more suited to the so-called conventional practice and the stiffening blade is activated to obtain a more rigid flexural shoe, better adapted to the practice of the skater's step.

The same shoe can thus, depending on the position of the end of the stiffening blade, have a different flexural stiffness. This possibility of adjustment is particularly advantageous in competition for example, combining a combination of two events such as a classic event immediately followed by a test not the skater without interruption of the timer. This avoids the use of mixed shoes whose rigidity is intermediate between a soft shoe and a rigid shoe and would rather be an unsatisfactory compromise in both practices.

Other advantages and characteristics will appear on reading the description of the invention, as well as on the appended figures in which:

FIG. 1 represents a perspective view of the lateral side profile of a Nordic ski boot according to a first embodiment, in a case where the inner liner is not placed in the shell,

FIG. 2 is a view of the medial side profile of the shoe of FIG. 1,

FIG. 3 represents a view from below of the shoe of FIG. 1,

FIG. 4 represents a perspective view of the side profile of the ski boot shell, according to one of FIGS. 1 to 3,

FIG. 5 represents the shell of FIG. 4 and in which an inner liner is inserted,

FIG. 6 represents a perspective view of the right medial profile of the inner liner of FIG. 5;

FIG. 7 represents a view in perspective and from below of a shell on which schematically protected zones have been shown,

FIG. 8 is a schematic side view of an alternative embodiment of the shell,

FIG. 8a is a view from above of the shell of FIG. 8,

FIG. 9 is a view from above of the shell of FIG. 8,

FIG. 10 represents a sectional view A-A of the blade-shaped part in the bending zone of the shell of FIG. 8,

FIG. 11 represents a perspective view of the medial profile of a Nordic ski boot shell according to a second embodiment in the assembled state, FIG. 12 represents the shell of FIG. 11, seen in perspective from above, in the disassembled state,

FIG. 13 represents the shell of FIG. 11, seen from below, in the disassembled state,

FIG. 14a is a schematic view in longitudinal section of a Nordic ski boot shell according to a third embodiment,

FIG. 14b represents a sectional view of a Nordic ski boot shell according to a fourth embodiment, which is a variant of the third embodiment,

FIG. 15a is a diagrammatic sectional view along a longitudinal median plane of a shell according to a fifth embodiment,

FIG. 15b represents a bottom view of the shell of FIG. 15a with the stiffening blade in the active position,

FIG. 15c shows a sectional view along a longitudinal median plane of a shoe provided with the shell of FIG. 15a fixed to a ski with the foot in reverse bending and the stiffening blade in the active position, the boot being not represented,

FIG. 15d shows the shoe of FIG. 15c fixed to the ski with the foot in flexion and the stiffening blade in the inactive position,

FIG. 15e shows the shoe of FIG. 15c fixed to the ski with the foot in flexion and the stiffening blade in the active position,

FIG. 16a represents a perspective view of a shell according to a sixth embodiment,

FIG. 16b represents a variant of a shell according to a seventh embodiment, and

- Figure 17 is similar to Figure 8, for an eighth embodiment.

In these figures, the identical elements bear the same reference numbers.

The upper, lower, front and back, lateral and medial positions are used with reference to the foot of a user.

Figures 1 to 3 show a ski boot 1 for Nordic skiing in which the skier lifts the heel alternately, such as telemark, ski touring or cross-country skiing. The inner liner is not represented. In the description, the different types of skis for the practice of Nordic skiing disciplines will be referred to as the general term cross-country ski or even simply ski.

The shoe 1 comprises a shell 2 (Figure 4), an outer sealing layer 3 partially enveloping the shell 2 and a collar 4 hinged to the shell 2 (Figures 1 and 2).

Better visible in Figure 4, the shell 2 comprises a peripheral wall 5 surmounting a sole portion 6 and an upper opening 7 formed in the upper part of the peripheral wall 5 for the insertion of the skier's foot.

The shell 2 is an envelope having a shape adapted to wrap a foot. The shell 2 is relatively rigid but has a flexion zone Z located at the articulation of the metatarsals. The flexion zone Z is formed by recesses in the peripheral wall 5 of the shell 2. The recesses are two lateral and medial zones extending from either side of the upper opening 7, from the upper opening 7 to the sole portion 6. The flexion zone Z allows the ski boot 1 to be flexible in bending at the joint metatarsals, to allow the unfolding of the foot during the practice of skiing.

The flexion zone Z thus delimits a front cradle or tip at the tip of the shell 2, and a rear cradle at the heel end of the shell 2.

The upper opening 7 of the shell 2 extends at least from the zone of the ankle to the flexion zone Z, which gives a certain flexibility to the peripheral wall 5 at the rear cradle, and which allows tightening and holding the foot.

The front cradle protects the toes of the skier and helps maintain the foot. The front cradle may have an upper central notch 8, in the extension of the upper opening 7, as shown in FIG. 4. It will be seen later that the front cradle can also be removed and replaced by a simple protective end cap. toes, without special stiffening function.

The lateral and medial recesses of the flexion zone Z may have parallel opposite edges, the recesses being, for example, slightly obliquely towards the tip of the shell 2, as can be seen in FIGS. 4 and 5. According to another example shown in FIG. 8, the recesses of the flexion zone Z are flared upwards. Recesses with opposite parallel edges or flared upwards are preferred so that in bending, the front cradle does not touch the rear cradle.

The width of the recesses 1f of the flexion zone Z at the narrowest point (FIGS. 4 and 8) is at least greater than 5 millimeters to allow bending. The width lf is for example between 20 and 30 millimeters and is preferably of the order of 25 millimeters.

It is furthermore provided that the thickness ep of the lateral and medial portions of the peripheral wall 5 is at most less than 1.5 millimeters, which makes it possible to obtain a ski boot 1 which has the required qualities of both rigidity and of low weight.

The shell 2 is for example entirely made of composite materials, such as carbon fibers, glass fibers or aramid. Thanks to the composite materials, excellent rigidity and low weight can be obtained with a thickness of the lateral and medial very thin, between 0.5 and 1, 2 millimeters. It is thus possible to obtain ski boots weighing about 300g per foot instead of 600g to 700g for a shoe of the state of the art.

With a shell of composite material, it is also possible for the fibers of the blade portion 6 to be unidirectional in the flexion zone Z.

As shown in Figure 8a, at least a percentage of the fibers constituting the blade portion are oriented in the longitudinal direction L of the shoe. These fibers are for example located in the thickness of the blade-shaped portion, that is to say away from the faces which delimit it. It can also be said that the unidirectional fibers are located in a central region of the blade-shaped portion, in the direction of the thickness.

Alternatively and as shown in FIG. 9, the blade-shaped portion 6 is made of composite materials and the fibers of the composite material are crossed in the bending zone. For example, the first fibers form an angle of between + 40 ° and + 70 ° with the longitudinal axis L of the blade-shaped portion 6 and the second fibers form, for example, an angle of between -40 ° and -70 ° with the longitudinal axis L of the blade-shaped portion 6. For example, the first fibers form an angle of the order of 60 ° with the longitudinal axis L and the second fibers form an angle of the order of -60 °. The crossed fibers make it possible to ensure continuity of the torsional rigidity of the shell 2 'in the flexion zone Z which is substantially less rigid in torsion of the recesses.

The shell 2, 2 'is for example entirely made of carbon fibers. In this case, good rigidity and low weight can be obtained with a thickness of the lateral and medial parts of between 0.5 and 0.8 millimeters.

According to another example, the peripheral wall 5 at least is made of glass fibers. In this case, good rigidity and low weight can be obtained with a thickness of the lateral and medial parts of the rod portion 5 of between 0.8 and 1.2 millimeters.

To further reduce the weight without impairing the qualities of rigidity, it can be provided to provide lightening holes in the peripheral wall 5 of the shell 2, forming for example a mesh shell (not shown).

In another example, the peripheral wall 5 at least is made of injected plastic material. In this case, a good rigidity and a low weight can be obtained with a thickness of the lateral and medial parts of the peripheral wall less than or equal to 1.5 millimeters. It is then expected that the shell 2, 2 'has lightening holes to ensure a low weight while having good rigidity.

It is also conceivable that the materials of the front and rear cradles are different from one another, chosen for example from different composite materials (carbon fiber, fiberglass or aramid) and / or by combining a composite material with a plastic material. However, it is preferred that the blade-shaped portion 6 is made of carbon fibers.

Furthermore, it is expected that the thickness d of the blade-shaped portion 6 in the flexion zone Z is at most less than 4 millimeters, to allow a comfortable flexion at the joint of the metatarsals. Fig. 10 shows a section of the blade-shaped portion 6 in the flexion zone Z. The thickness d of four millimeters represents the maximum thickness between the highest point and the lowest point of the thickness of the blade. the blade-shaped portion 6 in the flexion zone Z.

It can also be provided that between the blade-shaped portion 6 and the upper opening 7, the thickness ep of the lateral and medial portions of the wall 5 thins. For example, for a shell 2 entirely made of carbon fibers, the thickness at the blade-shaped portion 6 may vary and may be between 1.2 millimeters in the vicinity of the portion of blade shape 6 and being only of the order of 0.5 millimeters at the level of the upper opening 7. The thinning of the thickness ep of the peripheral wall 5 locally increases its flexibility, particularly in terms of lateral and medial parts, which allows a tightening of the rear cradle around the progressive and enveloping foot.

In this first embodiment, whether made of one or more different materials, the shell 2, 2 'is monobloc, that is to say that it comprises a single piece. The shell 2, 2 'has a uniform and smooth surface, and the blade-shaped portion 6 and the peripheral wall 5 are connected continuously. Thus, the shell 2, 2 'is comfortable for the foot of the user. Thus, with a thickness of the lateral and medial parts of the peripheral wall 5 less than 1.5 millimeters and a flexion zone Z formed by recesses in the wall 5 of the shell 2, 2 'extending from the upper opening 7 of the wall 5 to the blade-shaped portion 6, the shell 2, 2 'has good torsional rigidity while having good flexural flexibility and a controlled weight.

The boot 1 further comprises a front fastening element 9 associated with the blade-shaped portion 6 of the shell 2, upstream of the flexion zone Z (FIG. 3). The front binding member 9 is provided with a transverse pivot 10 rotatably engaging the front attachment to the ski. The front fastening element 9 is for example screwed to the front cradle of the shell 2. For this, it can be provided that the shell 2 has through holes and inner shoulders arranged around the through holes. The inner shoulders are formed inside the shell 2. The through holes are adapted to receive fastening screws 11. The shoulders are adapted to receive and completely house the heads of the fastening screws (or nuts). This ensures that the fixing screws 11 are perfectly integrated inside the shell 2 and can not hurt the foot of the user.

To improve the comfort of the user and ensure good transverse support of the ankle, the shell 2, 2 'may also include side and medial amounts of protection 12, on both sides of the malleolus, to better protect the malleolus of the user. It is furthermore possible to articulate the collar 4 of the boot 1 on these uprights 12.

In addition, the underside of the blade-shaped portion 6 (or heel) can define two guide grooves 48 for the transverse support of the boot 1 secured to the binding of the ski when the heel of the boot is supported on the ski.

The outer sealing layer 3 is waterproof material, hydrophobic to resist snow, rain and ice and elastic material to facilitate the insertion of the foot in the upper opening. It is for example made of neoprene-based elastic fabric, a polyurethane layer, or any equivalent material. The outer sealing layer 3 is for example fixed on the one hand to the edges of the blade-shaped portion 6 and on the other hand, to the rear cradle. The outer sealing layer 3 covers the lateral and medial recesses of the flexion zone Z and part of the upper opening 7. It thus makes it possible to protect the user's foot.

The shoe 1 also comprises an inner liner 20, for example made of polar textile, received in the shell 2, 2 '. The inner liner 20 provides softness and warmth to user, and avoids the foot to rub the edges of the shell 2. It also allows to cover the foot of the user in the flexion zone Z. An example of inner shoe 20 is shown in Figures 5 and 6.

In the illustrative example of Figures 1 and 2, the shoe 1 also comprises two clamps 13a, 13b and a band 14. The band 14 tightens the shoe on the foot of user at an angle between the bending zone Z and the cradle back. The first clamp 13a is adapted to connect the lateral and medial portions of the rear cradle at the instep. It allows adjustment of the tightening of the rear cradle. The first clamp 13a and the band 14 also maintain the outer sealing layer 3 and the shell 2 together on the foot of rutilisateur. The second clamp 13b is intended to adjust the clamping collar 4 around the user's ankle. Of course, alternatively or additionally, the boot may comprise other tightening means, such as a lace device or any equivalent.

In order not to unnecessarily burden the hull 2, only certain areas of privileged contact are provided with protective elements to protect the hull 2 and allow walking safely. The zones provided with these elements comprise, for example, the heel zone 15 defining the guide grooves 48 and the front zone 19 of the shell 2 which are the contact zones at the start and at the end of the pitch, the medial zones 16 and lateral portion 17 of the flexion zone Z as well as the lower central portion 18 of the flexion zone Z which are preferred contact zones for contact with the ski for standing or during the unwinding of the foot (FIG. 7). The protection elements 16 and 17 are provided to protect the flexion zone Z, particularly at the recesses, against shocks or friction in a track in the snow.

Thus, the geometry and the choice of the materials of the shell 2, 2 'make it possible to obtain a boot 1 having a good torsional rigidity and a good flexibility in flexion, and which is comfortable.

According to a second embodiment shown in Figures 11, 12, 13, 14a, and 14b, the shell is made of several separate elements assembling together.

In the first example shown in Figures 11, 12 and 13, the shell 20 is made of three elements: the front cradle 21, the rear cradle 22 and the blade-shaped portion 23. The front cradle 21 and the rear cradle 22 are for example fiberglass. and the blade portion 23 is made of carbon fiber. The front and rear cradles 21, 22 have rounded shapes, in particular in the flexion zone Z. These three elements 21, 22, 23 are joined together for example by gluing, welding or mechanical assembly between the lower cradle curbs and the periphery of the cradles. the blade-shaped portion 23.

The front fastening element 24 of the boot is distinguished in FIG. 13. It can also be seen in FIG. 12 that the heads of the fastening screws 11 are received in the internal shoulders formed inside the shell 20 and that do not go beyond it.

On the other hand, in this example, the front fastener 24 has an additional transverse bar 25 set back from the transverse pivot 10. The cross bar additional can be used as an option, being connected to an elastic return means connected to the ski. This option is particularly suitable for the practice of the alternative or classic step which consists in advancing in two parallel traces.

According to an example shown in Figures 14a and 14b, the shell 26; 26 'is made of two separate elements joining together: the front cradle 27; 27 'and the rear cradle 28; 28.

With reference to FIG. 14a, the front cradle 27 has a peripheral wall 29 and a blade-shaped portion 30 and the rear cradle 28 comprises a peripheral wall 31 and a blade-shaped portion 32. The shell 26 further comprises a means 33 for securing the front and rear cradles 28 at the overlap of the front and rear blade portions 30, 32.

The fixing means is for example removable. For example, it is provided that the fixing means 33 comprise at least one fixing screw. Thus, it is possible to adjust the ski boot according to the size of the skier and the width of the recesses of the flexion 2one Z by more or less advancing the cradle before 27 relative to the rear cradle 28.

In the example of Fig. 14a, the forward blade-shaped portion 30 extends under the rear blade-shaped portion 32. The fastening means 33 has two fastening screws which fit under the rear peripheral wall 31 in the forward blade-shaped portion 30 into the rear blade-shaped portion 32, thereby connecting together the two cradles 27, 28.

In the example of Figure 14b, the rear blade-shaped portion 32 'extends below the blade-shaped portion before 30'. The fastening means 33 'comprises a single fastening screw which is inserted under the front peripheral wall 29', in the rear blade-shaped portion 32 'into the front blade-shaped portion 30', thereby connecting together the two cradles 27 ', 28'.

Alternatively, the front and rear cradles 27, 28; 27 ', 28' are permanently fixed for example by gluing, welding or mechanical assembly.

It is further possible to insert a flexible layer between the front and rear blade portions or bottoms 30, 32; 30 ', 32'.

Thus, in either of these two embodiments, the blade-shaped portion 30, 32; 30 ', 32' is not doubled in the flexion zone Z and remains less than 4 millimeters to allow bending of the shoe.

FIGS. 15a, 15b, 15c, 15d and 15e illustrate a fifth embodiment in which the shell 34 comprises a stiffening blade 35.

As can be seen in FIGS. 15a and 15b, the stiffening blade 35 extends at least under the flexion zone Z. It is able to take an active position in which it thickens the blade-shaped portion 36 in the Z bending zone being superimposed on the blade-shaped portion 36 (Figure 15e) and an inactive position in which the end 37 of the stiffening blade 35 is free (Figures 15d).

The free end 36 of the stiffening blade 35 extends for example towards the rear of the flexion zone Z, the front end being integral with the blade-shaped portion 36 of the front cradle. 38. The stiffening blade 35 has for example a wider shape front side than rear side. The rear side tapers to the free end 37.

Thus, the stiffening blade 35 is active in reverse bending, that is to say when the user leans back (arrow Fl) and the front of the shoe is maintained on the ski 50 for example (Figure 15c). The stiffening blade 35 stiffens the blade portion 36 in the active position and prevents this reverse bending of the shell 34. This is particularly useful for a mountain ski boot which will tend to bend upside down (depending on the Fl direction) when pressing on the collar 4 of the shoe. A hull devoid of this blade could risk breaking simply on a back support.

The free end 37 may further be retained in the active position, that is to say integral with the blade-shaped portion 36 of the rear cradle 39, by a removable retention means.

The removable retaining means comprises for example a pivot 40 manually operable by a locking lever 41 secured to the pivot 40 (Figure 15b). The pivot 40 can thus pivot (arrow F2 in FIG. 15b) between the active position in which it holds the end 37 of the stiffening blade 35 to the blade-shaped portion 36 (FIG. 15b) and an inactive position in which the pivot 40 is pivoted away from said end 37 (Figure 15a).

The front end of the stiffening blade 35 being integral with the blade-shaped portion 36 of the front cradle 38, the free end 37 of the stiffening blade 35 is biased to the inactive position during the unwinding of the foot. Thus, when the shell 34 is bent and the stiffening blade 35 is in the inactive position, the stiffening blade 35 is inoperative, it does not contribute to stiffen the shell 34 which remains flexible in the bending zone thanks to the recesses in the flexion zone Z and the blade-shaped portion 36 thin (Figure 15d).

In the active position, when the shell 34 is flexed, the stiffening blade 35 is held integral with the blade-shaped portion 36 at the rear of the flexion zone Z by the pivot 40. The thickness of the shaped part blade 36 doubled stiffening blade 35 makes the shell 34 more rigid, making it more difficult flexion of the foot (Figure 15e).

Thus, the same shoe can be used for different Nordic skiing practices. The stiffening blade 35 is deactivated in order to obtain a flexible bending shoe that is more suitable for the so-called conventional practice, and the stiffening blade 35 is activated to obtain a more rigid flexural shoe, better suited for practicing the skater's step.

The same shoe can thus, according to the position of the end of the stiffening blade 35, have a different bending stiffness. This possibility of adjustment is particularly advantageous in competition for example, combining a combination of two events such as a classic event immediately followed by a test not the skater without interruption of the timer. This avoids the use of mixed shoes whose rigidity is intermediate between a soft shoe and a rigid shoe and would rather be an unsatisfactory compromise in both practices. This principle can also be used in mountain boots, to make them rigid and allow the mounting of crampons. According to a sixth embodiment shown in FIG. 16a, the ski boot comprises two straight struts 43 connecting the lateral and medial parts of the rear cradle 44 with the lateral and medial parts of the front cradle 45. The parts of the front cradle 45 are defined by the ends of the shell 42 between the upper central notch 8 of the front cradle and the recesses of the flexion zone Z. The parts of the rear cradle 44 are defined by the ends of the shell 42 between the upper opening 7 and the recesses of the flexion zone Z.

The stays 43 are formed of a web of fabric for example of Kevlar fiber (trademark). The stays 43 serve to prevent rear bending of the hull 42 and also contribute to the tightening of the hull 42.

According to an alternative embodiment shown in Figure 16b, the ski boot has a single stay 46 having a general shape in "Y". The stay 46 connects the lateral and medial parts of the rear cradle 44 with the front cradle 47. Unlike the previous variant, the front cradle 47 is "full", that is to say that it has no notch upper center.

The embodiment proposed in Figure 17 corresponds to a case where the shoe 1 is devoid of front cradle. This means that the shell only includes the rear cradle and the blade-shaped part. As a result, the flexion zone Z extends from the metatarsal to the front end.

In all cases the invention is made from materials and according to implementation techniques known to those skilled in the art.

Naturally, the invention is not limited to the embodiments described above, and includes all technical equivalents that fall within the scope of the claims that follow.

Claims

I. Shoe (1) intended in particular for practicing a sport of sliding on snow or walking, characterized in that it comprises an outer shell (2, 2 ', 20, 26, 26', 34, 42) of rigid material, the shell (2, 2 ', 20, 26, 26', 34, 42) comprising a rear cradle (22, 28, 28 ', 39, 44) provided to contain the heel of the user the rear cradle (22, 28, 28 ', 39, 44) being extended forwardly by a blade-shaped portion (6) defining a flexion zone, the rear cradle (22, 28, 28', 39) 44) having a peripheral wall (5, 31) and a bottom, the bottom of the cradle and the blade-shaped portion partly defining the sole of the shoe, and characterized in that it comprises an inner liner (20). ).

2. Shoe (1) according to claim 1, characterized in that the hull

(2, 2 ', 20, 26, 26', 34, 42) comprises a front cradle (21, 27, 27 ', 38, 45, 47), the blade-shaped portion connecting the rear cradle to the front cradle, the blade-shaped portion extending at the metatarsal level of a user.

3. Shoe (1) according to claim 1 or 2, characterized in that the rear cradle and the blade-shaped portion are monobloc.

4. Shoe (1) according to claim 1 or 2, characterized in that the rear cradle and the blade-shaped portion are separate elements.

5. Shoe (1) according to one of claims 1 to 4, characterized in that the thickness of the peripheral wall (5) of the rear cradle is less than 1.5 millimeter.

6. Shoe (1) according to one of claims 1 to 5, characterized in that it comprises a front cradle, and in that the thickness of the peripheral wall of the front cradle is less than 5 mm.

Shoe according to one of the preceding claims, characterized in that the thickness

(ep) of the blade-shaped portion (6) in the bending zone (Z) is less than 4 millimeters.

8. Shoe according to one of the preceding claims, characterized in that between the bottom

(6) and the upper opening (7), the thickness (ep) of the peripheral wall (5) thins.

9. Shoe according to one of claims 1 to 8, characterized in that the minimum width of the bending zone (Z) is at least greater than 5 millimeters.

10. Shoe according to claim 9, characterized in that the minimum width of the bending zone (Z) is between 20 and 30 millimeters and is preferably of the order of 25 millimeters.

I I. Shoe according to one of claims 1 to 10, characterized in that the shell is made entirely of composite materials and in that the thickness (ep) of the peripheral wall (5) is between 0.5 and 1, 2 millimeters.

12. Shoe according to claim 11, characterized in that it is entirely made of carbon fibers and in that the thickness (ep) of the peripheral wall (5) is between 0.5 and 0.8 millimeters.

13. Shoe according to claim 11, characterized in that the peripheral wall (5) at least is made of glass fibers and in that the thickness (ep) of said peripheral wall (5) is between 0.8 and 1.2 millimeters.

Shoe according to one of claims 1 to 13, characterized in that the blade-shaped part (6) is made of composite materials and comprises unidirectional composite material fibers in the flexion zone ( Z).

15. Shoe according to one of claims 1 to 10, 13 or 14, characterized in that the flexion zone (Z) defines a front cradle and a rear cradle, the materials of the front and rear cradles being different one of the other, the blade-shaped portion (6) being made of carbon fibers.

16. Shoe according to one of claims 1 to 15, characterized in that lightening holes are formed in the rear cradle.

17. Shoe according to one of claims 1 to 10 or 15, taken together with claim 16, characterized in that the cradle at least is made of plastic and in that the thickness (ep) of the cradle is lower or equal to 1.5 millimeters.

18. Shoe (1) according to one of the preceding claims, characterized in that the flexion zone (Z) defines a front cradle and a rear cradle, the shell comprising the front cradle and the rear cradle, the hull comprising a means of fixing the front and rear cradles at the level of an overlap of the front and rear bottoms of the cradles.

19. Shoe (1) according to one of the preceding claims, characterized in that the bottom of the rear cradle extends under the bottom of the front cradle, the fixing means being arranged under the front cradle.

20. Shoe (1) according to one of the preceding claims, characterized in that the front bottom extends under the rear bottom, the fixing means being arranged under the rear cradle.

21. Shoe according to one of claims 18 to 20, characterized in that the fastening means (33; 33 ') is removable.

22. Shoe according to one of claims 1 to 17, characterized in that the shell is in one piece.

23. Shoe according to one of the preceding claims, characterized in that the shell comprises a stiffening blade (35) extending at least under the bending zone (Z), said stiffening blade (35) being adapted to take an active position in which said stiffening blade (35) thickens the sole in the bending zone (Z), and an inactive position in which the end (37) of the stiffening blade (35) is free.

24. Shoe according to claim 23, characterized in that the free end (37) of the stiffening blade (35) extends rearwardly of the flexion zone (Z).

25. Shoe according to claim 24, characterized in that the free end (37) of the stiffening blade (35) is adapted to be retained in the active position by a removable retaining means (40).

26. Shoe according to one of the preceding claims, characterized in that it comprises lateral amounts of protection (12) at the malleoli.

27. Shoe according to one of the preceding claims, characterized in that the flexion zone (Z) defines a front cradle and a rear cradle, and in that the front cradle has an upper central notch (8).

28. Shoe according to one of the preceding claims, characterized in that the shell has through holes adapted to receive fixing screws (11), and in that it comprises internal shoulders arranged around the through holes, adapted for housing the heads of said fixing screws (11).

29. Shoe according to one of the preceding claims, characterized in that the flexion zone (Z) defines a front cradle and a rear cradle in the shell (42) and in that the shoe has two straight struts (43) connecting respectively the walls of the rear cradle (44) with the walls of the front cradle (45).

Ski boot according to one of claims 1 to 28, characterized in that the flexion zone (Z) defines a front cradle and a rear cradle in the shell (42 '), and in that the shoe has a stay (46) having a "Y" shape connecting the walls of the rear cradle (44) with the front cradle (47).