EP2674049A1 - Internal liner for sports shoe - Google Patents

Abstract

The method involves making an outline for an open liner (4.3) comprising parts of a liner rod (4.4) intended to cover a heel and malleoli of foot of a user. The outline of the open liner is heated, positioned and compressed on a punch. The compressed outline is cooled to print by curving a shape of the punch to the outline. The curved outline and the liner rod are assembled with each other. A sole is mounted to the assembly formed by the curved outline and the rod to form an internal liner (4). An independent claim is also included for an internal liner.

Description

The present invention relates to a method of industrial manufacture of an inner liner, in particular for use in an alpine ski boot comprising a rigid shell and said inner liner. Alpine ski boots are not the only ones to include an outer shell and an inner liner. We find this type of construction for some hiking shoes, some cross-country ski boots or snowboard. In general, the invention aims at any type of inner boot intended to be placed in an outer shell. Typically, shoes of this kind also comprise an upper part, the collar, and an outsole on said shell, this outsole being intended to cooperate with a binding on a ski and the collar being mounted on the hull bottom pivotally so as to allow relative rotation between the collar and the shell bottom. This type of ski boots is conventionally used in the field of downhill skiing, ski touring, or in the context of skating type cross-country skiing in that the shoe used has a rigid body. The invention also relates to a flexible inner boot, particularly for a ski boot, the inner boot being able to be manufactured by the method according to the invention and having left and right subassemblies comprising assembled support pieces. Slippers of this kind are conventionally manufactured by gluing or sewing of its components made of different materials.

Generally, it is possible to classify the internal slippers of known ski boots into two types. The first type of inner bootie is known for entry-level ski boots. The slippers of this type are made simply and, therefore, are not exactly adapted to the anatomy of the foot of the user of the slipper, respectively of the ski boot The adaptation of the shape of the slipper to the outer contour of the foot, that is to say, the growths of the malleoli and the base of the heel and the hollows separating them from each other, is usually obtained by a process commonly called the patronage which consists of cutting flat panels which, when assembled end to end inside the liner, will define an empty volume intended to be occupied by the ankle of the slipper user. Or the outer volume of the slipper takes its final form when the foot is inserted, and is not particularly stable because the walls of the slipper are commonly made of a flexible material such as PVC. Therefore, if their manufacture has the advantage of being simple, the slippers of this type do not have a technically satisfactory external appearance because when they are not used their external appearance does not reflect the anatomy of the human foot. In addition, an internal liner of this type does not normally offer high comfort to its user.

The second type of known inner boot is reserved for very high-end ski boots or for very particular uses such as ski mountaineering and consists of slippers obtained by assembling so-called thermoformable foam panels, for example according to the document EP 617903 . These mousses are expensive and do not allow a very wide variety of confection. So all the slippers made in this way look alike. Consequently, they do not offer an aesthetically pleasing appearance, although they are considerably more expensive than the inner shoes of the first type. On the other hand, these foams, respectively slippers are generally intended to be thermoformed after the purchase of the corresponding ski boot by the end user and not during the manufacture of the slipper. Indeed, if one wants to thermoform these slippers before packaging, it is necessary to provide for each size of a range of shoe given a shape, called in English "last", which considerably increases the cost of manufacture. The exact adaptation of the boot to the foot of a user is therefore carried out individually at the point of wind and takes a long time, typically between ten and fifteen minutes, during which the customer must wear the boot on his foot, the slipper being simultaneously heated for thermoforming. So, this procedure of adapting the shape of the shoe to the anatomy of the foot can be long and unpleasant for the buyer. In short, if these slippers offer, under ordinary conditions, improved comfort compared to the slipper of the first type because of the adaptation to the user's foot, they are not, in principle, not adapted to be manufactured in large series by a industrial manufacturing process sufficiently economical, much more expensive to buy because of the price of materials, less rich in terms of decoration and impose certain constraints on the buyer before the first use because the thermoforming is done individually after the 'purchase.

The document EP 711,515 discloses a third type of shoe in which a foam wedging element of thermoplastic nature makes it suitable to adjust to the specific volume of the foot of the skier. The adaptability is in this case obtained by a localized settlement of certain portions of the wedging element. To avoid, among other things, that the foams thus packed do not constitute too rigid portions, they are micro perforated. Such a method gives no particular shape to the shoe before the end customer has completed the individualization steps. On the other hand, the areas where the foam of the wedging element is packed, offers less comfort than that where the foam is not. However, it is in these areas that the user needs more comfort. Indeed, these areas correspond in particular to the protuberances of the user's foot.

In summary, the solutions of the prior art currently known do not allow, to the knowledge of the applicant, to bring together all the characteristics desirable for an inner liner, in particular for use in a ski boot, in particular, on the one hand, in terms of a good adaptation of the shape of the shoe to the outer contour of the human foot and - secondly, in terms of industrial production relatively simple, effective, and comparatively inexpensive, this while nevertheless ensuring a technical aspect and aesthetic slipper reflecting the anatomy of the human foot, a high comfort for the user, including a little free space to receive the foot of the user also in conditions different from those at the time of purchase, a possibility simple acquisition of the slipper for the customer, especially without slipper individualization stage requiring an effort on the part of the purchaser, as well as of course a price mo dated slipper.

The object of the present invention is therefore to overcome the drawbacks of the currently known internal slippers and to achieve the above-mentioned advantages, in particular to provide an internal slipper, in particular for use in a ski boot, which is well suited to be manufactured industrially and which reproduces the anatomy of the foot of a user of the bootie, especially at the heel and at the level of the malleolus, presenting a technical aspect adequate, but not requiring much effort on the part of a buyer to get the slipper in a ready-to-wear condition, combined with a moderate price for the slipper. Another object is to propose a corresponding manufacturing method of such a slipper which is particularly economical, easily adaptable in terms of changes potentially necessary in terms of the aesthetic appearance to be given to a range of slippers, and which greatly improves the aesthetics of the slipper.

For this purpose, the present invention proposes a method of industrial manufacture of an inner liner, in particular for use in a ski boot comprising a rigid shell and said inner liner. This method of manufacture comprises several steps that need not necessarily be performed one after the other in the order mentioned below.

The method according to the invention is characterized by the prior preparation of an open liner blank comprising one or more thermoformable reinforcing sheets. The shaping of the inner boot liner is done before the completion of the inner liner. That is to say before closing the bottom of the blank by mounting a sole. The thermoformable reinforcing sheets are likely to be deformed when they are brought to a high temperature and they will keep the shape that is given to them during their cooling.

According to the invention, the reinforcing sheet or sheets are assembled before their thermoforming to one or support pieces. The support pieces and the reinforcing sheets may consist of several panels with each other, or may consist of a single panel.

According to the invention, the reinforcing sheet or sheets are provided to correspond, that is to say, in particular to cover, the lateral periphery of the heel and the areas of the protuberances of the malleolus.

According to the invention, the reinforcing sheets may be assembled to the inner faces of the support pieces or to the outer faces thereof, in the latter case, the reinforcing sheet or sheets may be visible once the bootie is finished.

In one of the embodiments, the description of which will be detailed below, at the beginning two support pieces are made in a flexible panel and dedicated to a left half, respectively to a right half of said inner boot, and two reinforcing sheets. corresponding to the left half and the right half of said inner boot are cut. Then, the support piece and the backing sheet dedicated to the left half are assembled to make a left subassembly for said inner liner, and the support piece and the backing sheet. reinforcement dedicated to the right half are assembled to manufacture a right subset for said inner boot. Then, the left subassembly and the right subassembly are assembled at their rear sides to obtain an open slipper blank. This open liner blank is heated, compressed on a punch, and then cooled to stamp the shape of the punch to the blank. Finally, the curved blank and a liner shank are assembled and a sole is mounted to the assembly formed by the curved blank and the liner shank to form the inner liner.

This makes it possible to produce a slipper having a technical aspect and reproducing the anatomical shape of the human foot by a process of purely industrial manufacturing as well as quite simple and relatively inexpensive, without the need for a stage of individualization at the point of sale involving the buyer of the boot, or even the corresponding ski boot.

The present invention also provides an inner boot adapted to be manufactured by this method, in particular for use in a ski boot, the inner boot having a left subassembly and a right subset assembled with each other, the subassemblies comprising support members made of a flexible panel and, in particular, reinforcing sheets assembled to said support pieces. In particular, the reinforcing sheets are dimensioned and have a shape capable of surrounding, in an assembled state of the shoe, the base of the heel and the malleolus of a user of said ski boot.

By these measures, it is possible to offer a high comfort slipper at an acceptable price, the slipper not only protecting the heel but also the malleolus of a user.

In addition, the present invention provides a ski boot having an inner liner according to the present invention, respectively an inner liner made by a manufacturing method according to this invention.

Other features, as well as the corresponding advantages, will emerge from the dependent claims, as well as from the description which sets forth the invention in more detail.

• La figure 1 montre une vue en perspective schématique illustrant une chaussure de ski adaptée à recevoir un chausson interne selon la présente invention.
• Les figures 2a et 2b montrent des vues en perspectives schématiques d'un chausson selon un premier mode de la présente invention, vu du coté extérieur et du coté arrière du chausson et quelques parties du chausson étant illustrées de façon transparente afin de faciliter la compréhension.
• Les figures 3a à 3f sont des illustrations des étapes de la méthode de fabrication d'un chausson selon la présente invention, y compris la figure 3e qui montre schématiquement une machine pour effectuer le galbage d'un chausson par chauffage suivi d'un refroidissement au cours de la méthode de fabrication.
• La figure 4 montre une vue de coté d'un chausson selon un deuxième mode de réalisation de l'invention.

The accompanying drawings show schematically and by way of example an embodiment of the invention.

• The figure 1 shows a schematic perspective view illustrating a ski boot adapted to receive an inner liner according to the present invention.
• The Figures 2a and 2b show schematic perspective views of a liner according to a first embodiment of the present invention, seen from the outer side and the back side of the liner and some parts of the liner being illustrated in a transparent manner to facilitate understanding.
• The Figures 3a to 3f are illustrations of the steps of the method of manufacturing a shoe according to the present invention, including the figure 3e which shows schematically a machine for shaping a liner by heating followed by cooling during the manufacturing method.
• The figure 4 shows a side view of a shoe according to a second embodiment of the invention.

The invention will now be described in detail with reference to the accompanying drawings illustrating by way of example an embodiment of the invention. The present invention relates to an inner liner 4, particularly for use in a hard shell ski boot 10 having a lower portion, the shell bottom 1, and, normally but not necessarily, an upper portion, the collar 2. It is preferably, and as illustrated in the figures, an alpine ski boot type "front entrance", but it can also be a ski boot for the practice of ski touring , or even cross-country skiing, provided that the shoe has a substantially rigid shell as is recommended for example for skating, or other sports requiring such type of shoe, and inside which is housed an inner bootie 4 made of a flexible material to receive foot from the user of the shoe.

As illustrated schematically and by way of example in a perspective view of the figure 1 , illustrating in more detail and by way of example the ski boot 10 with the shell bottom 1, the collar 2, and the inner liner 4, said shell bottom 1 comprises an outer sole 1.1 formed integrally with said rigid shell 1 and intended to cooperate with a fixation on a ski not shown in the figures. Said collar 2 is adapted to be pivotally mounted on the shell bottom 1, in order to allow relative rotation of a certain angular extent between the collar 2 and the shell bottom 1 giving the user the possibility of making movements during the practice of skiing or even to walk without being bothered by the rigid shell and while having a good hold in the ski boot 10. The bottom shell 1 and the collar 2 comprise closure elements 6, such as hooks or straps, allowing the user to tighten the shoe of ski 10 around his foot. To allow this rotation, the ski boot 10 further comprises hinge means 3 for performing said relative rotation between the collar 2 and the shell bottom 1. The collar 2, the hinge means 3 as well as the closure elements 6 are not important for the present invention, they will not be described in more detail later and may be constituted by any means known to those skilled in the art.

The Figures 2a and 2b show schematic perspective views of the outer side and the rear side of an inner liner 4 according to a first embodiment of the present invention. The liner 4 has a left half 4.1 and a right half 4.2, these halves being made of a flexible panel, for example polyvinyl chloride (PVC) or PE (polyethylene). The flexible panel may also consist of a thermoformable material, but this alternative is less preferred because of the high costs of this material. Each of these halves has a liner shaft 4.4.1, 4.4.2 forming the top of the liner and a subassembly 4.1.1, 4.2.1 forming the side walls of the bottom of the liner. Each left subassembly 4.1.1, respectively right 4.2.1 comprises a left support piece 4.1.1.1, respectively right 4.2.1.1 and a left reinforcement sheet 4.1.1.2, respectively right 4.2.1.2. This is noticeable at best figures 2b as well as 3c, these figures also showing that the left subassembly 4.1.1 and the right subassembly 4.2.1 are assembled to give a set 4.3, hereinafter referred to as the open liner blank 4.3.

Preferably, the reinforcing sheets 4.1.1.2, 4.2.1.2 have a textile coated with thermoplastic resin or equivalent and are in the form of an insert of a very low thickness. Preferably, the thermoplastic resin is Thermoflex RT C. The thermoflex RT C is available in sheet form with a typical dimension of 1.0 m to 1.5 m. and a thickness between 0.5 mm and 1.5 mm, which can be glued on a suitable support with an adhesive such as ethylene vinyl acetate (EVA), which is a very common adhesive. The RT thermoflex is treated with moderate temperatures, between 90 ° C and 100 ° C for bonding and between 130 ° C and 140 ° C for its activation during thermoforming to print a shape three-dimensional desired said sheets, respectively inserts, for a period of time of only between about 20 seconds and 30 seconds. Because of these properties, thermoflex RT C or any other material with similar characteristics is ideally suited for use in the context of the present invention. Furthermore, the reinforcing sheets, respectively the inserts 4.1.1.2, 4.2.1.2 may be formed by woven or non-woven webs.

As it is visible Figures 2a and 2b and 3c, the reinforcing sheets 4.1.1.2, 4.2.1.2 are preferably dimensioned and have a shape able to surround, in an assembled state of the shoe 4, the base of the heel and the malleolus of a user of said shoe. ski. Contrary to the prior art, this makes it possible to give the liner 4 a three-dimensional shape reinforced and adapted to the external contour of the human foot, that is to say in particular to the growths of the malleoli and the base of the heel, as well as the hollows which separate them from each other, also on the upper part of the foot, respectively ankles.

The left subassemblies 4.1.1, respectively right 4.2.1, respectively the curved blank, and / or the liner shaft 4.4, having a straight portion 4.4.2, can of course be equipped with comfort foams and other components, as is the case with conventional slippers. Preferably, the comfort foams and other components mounted on the curved blank and / or on the liner shank 4.4 comprise a liner.

The Figures 3a to 3f are illustrations of the steps of the corresponding manufacturing method of a shoe according to the present invention. In particular, figure 3e schematically shows a machine used in this method for shaping a liner according to the present invention by heating followed by cooling during corresponding steps of the method of manufacture according to the present invention.

The figure 3a shows a left support piece 4.1.1.1, also called slap, cut and manufactured in a flexible panel, preferably PVC or PE, and a reinforcing sheet 4.1.1.2, also called insert, preferably in the form of a textile of low thickness and coated with thermoplastic resin or equivalent, preference thermoflex RT C. During this step of the method of manufacture of said slipper 4, the slaps and inserts are cut in particular giving them the form mentioned above being particularly suitable for the slipper can, in its assembled state, take the anatomical shape of the human foot. This includes inserts that must have a low part covering the heel of the foot and an upper part covering and extending beyond the malleoli of the foot.

The next step in the manufacturing method is to assemble the support piece 4.1.1.1 and the reinforcement sheet 4.1.1.2, which are illustrated in figure 3b in their assembled state with each other to give a subset 4.1.1, which is at the figure 3b for example the left subset. The right sub-assembly 4.2.1 is assembled in the same manner using a straight support piece 4.2.1.1 and a reinforcement sheet 4.2.1.2 instead of a left support piece 4.1.1.1 and a reinforcement sheet left 4.1.1.2, the left and right portions of the support pieces, respectively reinforcing sheets may also be cut out having an identical external shape, or the like, but shimmered along their rear limit. According to one embodiment of the manufacturing method of the invention, the support piece 4.1.1.1 and the reinforcing sheet 4.1.1.2 are assembled by gluing but other equivalent assembly techniques are imaginable.

The figure 3c illustrates the next step in the method of assembling the left subassembly 4.1.1 according to the figure 3b and a right subassembly 4.2.1 corresponding to the level of their rear sides to give a set, namely the blank of open liner 4.3 forming the side walls of the lower part of the liner 4. This assembly can, for example, be performed by sewing or welding.

The figure 3d shows, above, the open liner blank 4.3 comprising the sub-assemblies 4.1.1 and 4.2.1, in particular the reinforcing sheets 4.1.1.1, 4.2.1.2 and the supporting parts 4.1.1.1, 4.2.1.1 , seen from its inside, and below, the same sketch of open slipper 4.3 seen from its outside, a stem collar 4.4 being mounted on the upper limit of the open liner blank 4.3. Preferably, the rod collar 4.4 is made in one piece, for example made of an injected thermoplastic material. It is assembled to the draft 4.3 by sewing or welding. It may, however, also consist of a left half 4.4.1 and a straight half stem 4.4.2 assembled to each other. It is obvious that these components of the inner liner 4 have a shape adapted to each other, the rod 4.4 may extend to the calf of a user of the ski boot 10.

The figure 3e schematically shows one of the machines used in the present method for shaping a liner during the manufacturing method according to the present invention. The term "shaping" is used in this context in the sense of an industrial thermoforming performed generically for one or more shoe sizes and at the time of production of the shoe 4, respectively the shoe 10, contrary to the term "thermoforming""proper" which usually means the process of giving an anatomical shape to the shoe in a specific point of sale and in an individualized way to the buyer of the shoe 10.

In a first step, the blank must be heated to a temperature that will be chosen according to the different materials composing it. For example if the thermoflex is used, it will heat to a temperature between 130 ° C and 140 ° C. This heating step may be carried out by any suitable heating means, for example by blowing hot air, by insertion into an oven or by means of a machine such as that shown in FIG. figure 3 e.

The machine 5 comprises a first body 5.1 reproducing the anatomical shape of the rear part of a human foot and having the function of a punch 5.1 on which a subassembly, or even a blank of open liner 4.3 may be placed.

The machine 5 also comprises a second body 5.2 having the function of a matrix 5.2, the latter having an opening on its lower side and having inside it a support surface of shape corresponding to the body 5.1, is pressed against the punch 5.1 so that the subassembly, or even all the blank of open liner 4.3 is compressed between these two bodies 5.1, 5.2, thus printing the anatomical shape of the foot according to the model of the punch 5.1 in the reinforcing sheets made of thermoplastic material. In order to guarantee a sufficient pressure force, the machine 5 comprises a movement mechanism 5.3 making it possible to translate the body 5.2 towards and against the body 5.1, or vice versa. The open slipper blank is sandwiched between the punch and the die. The punch and the die may be both, or one of only two equipped with heating means.

In a second step, the subassembly, or even the blank of open liner 4.3 must be cooled. Preferably, a second similar machine of the machine represented in FIG. figure 3 e equipped with refrigeration means cooperating with the punch 4 so that the thermoformable material of the inserts, respectively reinforcing sheets, memorizes the anatomical shape of the foot which has been imparted to it by pressure using the punch. For this purpose, the punch may for example consist of a hollow aluminum body for injecting at a given moment a refrigeration fluid. The cooling can however also be achieved by any other suitable means, such as a cold air flow or the like. The cooling machine also comprises a matrix that presses the blank against the punch during the entire cooling phase. Both punch and die, or only one of them, are equipped with cooling means.

In a preferred embodiment, the trimming machine used comprises two punches and two dies. One of the punch / die pairs used to heat the blank while the other allows to cool. The two punch / die pairs are placed close to one another to limit operator manipulation.

Advantageously, the punches used in the bending machines according to the invention correspond to the anatomical shape of the rear part of the foot only, comprising the shape of the heel and malleoli, and not the entire foot. Thus, it is possible to use the same punch for several adjacent sizes. In the example described here, it will be possible to use a punch for 4 or 5 consecutive sizes. This feature of the invention leads to reduce the number of punches, and dies, necessary for the manufacture of all sizes of the same shoe model and therefore to reduce costs. In addition, it should be noted that it is the refrigerated punch which gives the final shape of the blank and which must have a shape that corresponds precisely to the desired shape, while the heating punch may have a more approximate shape. Industrially, this aspect has beneficial consequences. Indeed, to manufacture a whole range of size complete, only one hot punch may be sufficient, and a punch cooled for each group of 4 or 5, consecutive sizes. Of course, such an economy of means is impossible to achieve if one does not proceed, as in the case of the invention, the trimming of the open blank of the liner.

As illustrated in figure 3f , a draft 4.3 curved open liner and a rod collar 4.4 are then assembled to form all of the side walls of the inner liner 4. Of course, this step of the proposed method of manufacture can be performed before or after the shaping described above. FIG. 3g shows, in a particularly clear manner, the three-dimensional shape of the open and curved liner blank 4.3 obtained by shaping using a machine 5, represented in FIG. figure 3e . The growths for the heel 4.4.5 and the malleolus 4.4.6 of a user of the shoe 10 are clearly visible. Figure 3g also shows that, preferably, the seam or weld joining the left parts 4.1.1 and right 4.1.2 of the liner 4 is protected by a cover 4.4.3.

The final stages for the manufacture of a liner according to the invention will not be described here in detail because they correspond to conventional methods and known by the manufacturers of internal slippers of ski boots. They consist in particular to glue foam comfort, maintenance and / or other components such as a liner on the curved blank 4.3 and / or the liner shaft 4.4. Similarly, we will not describe here in detail the manufacturing step of "closing" the blank of the liner opened by mounting a sole. Conventionally, one will assemble, for example by sewing, a sole on the lower periphery of the curved blank 4.34. This sole, called first (sole) mounting "closes" the shoe, which then has its final shape. The following steps are finishing steps including the bonding of a (second) outsole.

The figure 4 shows a second embodiment of an inner liner according to the invention. Unlike the slipper described in figure 2a in this boot 4, the reinforcing sheets 4.2.1.2 covering the lateral sides of the heel and the protuberances of the malleoli are placed on the outer faces of the support sheet 4.2.1.1. Reinforcing sheets which as in the previous embodiment can be made by a cloth coated with a thermoplastic resin are visible outside the liner. This characteristic gives a technical aspect to the product. It will also be possible to use a fabric consisting of technical fibers, glass, carbon, etc. in order to further accentuate this technical aspect.

In view of the aforementioned explanations relating to the structure of the slipper and the method of manufacturing said slipper according to the present invention, it is obvious that such slipper and such method of manufacture provide many advantages and allow to achieve the stated goals in the introduction. In particular, the invention allows a good adaptation of the three-dimensional shape of the liner to the external contour of a user's foot and at the same time makes it possible to produce such a liner with a technical aspect by a purely industrial manufacturing process as well as quite simple and relatively inexpensive, this without the need for a stage of individualization at the point of sale involving the purchaser of the shoe, or even the corresponding ski boot. Thus, it is possible to offer a high comfort slipper at an acceptable price, not requiring a stage of individualization of slipper on the part of the purchaser, the slipper not only protecting the heel but also the malleoli of his user. In addition, this type of liner normally leaves a little free space to receive the foot of the user also in conditions different from those at the time of purchase and can be manufactured in a very wide variety of clothing.

Claims (16)

Method for the industrial manufacture of an inner liner (4), in particular for use in a ski boot (10) comprising a rigid shell (1) and said inner liner (4), the method of manufacture comprising the steps of - Making an open boot blank comprising at least the stem portions for covering the heel and malleoli of a user's foot - heat the open boot blank (4.3), - Position and compress the open liner blank (4.3) on a punch (5.1) and cool it to print the shape of the punch to the blank by shaping, - assemble the curved blank and a slipper shank (4.4), and - Mount a sole to the assembly formed by the curved blank and the liner shaft (4.4) to form the inner liner (4). Production method according to claim 1, characterized in that the preparation of the open liner blank comprises the following steps: - cutting a left support piece and a straight support piece made of a flexible panel and dedicated (4.1.1.1, 4.2.1.1) to a left half (4.1, respectively to a right half (4.2) of said inner boot (4) , - cutting two reinforcement sheets (4.1.1.2, 4.2.1.2) dedicated to the left half (4.1) and to the right half (4.2) of said inner liner (4), - assembling the support piece (4.1.1.1) left and the reinforcing sheet (4.1.1.2) dedicated to the left half (4.1) to manufacture a left subassembly (4.1.1) for said inner boot (4), and assembling the right support piece (4.2.1.1) and the reinforcing sheet (4.2.1.2) dedicated to the right half (4.2) to manufacture a right subset (4.2.1) for said inner boot (4), - assemble the left subassembly (4.1.1) and the right subassembly (4.2.1) at their rear sides to obtain an open liner blank (4.3), Production method according to claim 1, characterized in that the preparation of the open liner blank comprises the following steps: - Cutting a support piece corresponding to a slipper shaft member covering at least the heel and the malleolar areas of the foot of a user - Cut a reinforcing sheet corresponding at least to the heel and the areas of malleoli - assemble the support piece and the reinforcement piece Manufacturing method according to one of claims 2 or 3, characterized in that the reinforcing sheet or sheets are assembled on the inner face (s) of the support part (s). Manufacturing method according to one of claims 2 or 3, characterized in that the reinforcing sheet or sheets are assembled on the outer face or faces of the support part or pieces. Manufacturing method according to the preceding claim, characterized in that it further comprises, before the step of assembling the curved blank and the liner shank (4.4), the step of - Paste comfort foams and / or other components on the curved blank and / or the stem (4.4) liner (4). Method of manufacture according to one of the preceding claims, characterized in that the reinforcing sheets (4.1.1.2, 4.2.1.2) and the supporting parts (4.1.1.1, 4.2.1.1) are assembled by gluing. Manufacturing method according to one of the preceding claims, characterized in that the two subassemblies (4.1.1, 4.2.1) are assembled by sewing or welding. Manufacturing method according to one of the preceding claims, characterized in that the open liner blank is heated, then cooled to form in a trimming machine (5) having a punch (5.1) having the shape of the part back of the foot. Method of manufacture according to one of the preceding claims, characterized in that the reinforcing sheets (4.1.1.2, 4.2.1.2) are dimensioned and have a shape capable of surrounding, in an assembled state of the shoe (4), the base of the heel and the malleolus of a user of said ski boot (10). Method of manufacture according to one of the preceding claims, characterized in that the reinforcing sheets (4.1.1.2, 4.2.1.2) have a textile coated with thermoplastic resin or equivalent. Manufacturing method according to the preceding claim, characterized in that the flexible panel is made of PVC (Polyvinylchlorid) or PE (Polyethylene). Internal liner (4) capable of being manufactured by a method according to one of the preceding claims, in particular for use in a ski boot (10), the inner boot (4) having a left sub-assembly (4.1.1) and a straight subset (4.2.1) assembled with each other, the sub-assemblies (4.1.1, 4.2.1) having support pieces (4.1.1.1, 4.2.1.1) manufactured in one flexible panel, characterized in that said subsets (4.1.1, 4.2.1) comprise reinforcing sheets (4.1.1.2, 4.2.1.2) assembled to said support pieces (4.1.1.1, 4.2.1.1). Internal liner (4) according to the preceding claim, characterized in that the reinforcing sheets (4.1.1.2, 4.2.1.2) are dimensioned and have a shape adapted to surround, in an assembled state of the shoe (4), the base of the heel and the malleolus of a user of said ski boot (10). Internal liner (4) according to one of the preceding claims 13 to 14, characterized in that the reinforcing sheets (4.1.1.2, 4.2.1.2) have a textile coated with thermoplastic resin or equivalent. Ski boot (10), characterized in that it comprises an inner liner (4) according to one of claims 13 to 20 or an inner liner (4) manufactured by a method according to one of claims 1 to 12 .

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