EP0895727B1 - Sportsshoe with determined flexibility - Google Patents

Abstract

The boot has a shell (2) with a base (22) and a leg (12) which partially overlap at the back (8). The leg is articulated on the base by two axles (32). A flexible strip (7) is partially sandwiched between the leg and the shell and is fixed rigidly to the shell. It has a vertical slot (17) which opens at the top and its edges (17') extend under the leg.

Description

The subject of the invention is a ski boot of the front entry type with a variable volume having a shell consisting of a rod and a shell base which overlap at least partially and which are connected together pivotally and relates to a bending means for determining the flexibility characteristics of the rod relative to the base of the shell.

In known boots of this kind, such as the ski boots described in European patent applications EP 666 036 and EP 671 133, the European patent EP 350 023 and the German utility model G 92 17 787.5, the area of overlap of the rod with the shell base extends approximately over the entire region corresponding to the user's ankle for an obvious sealing issue. More specifically, the shell base has in the dorsal region of the shoe a more or less thin and flexible vertical extension which has come in one piece with its wall and which fits under the lower edge of the upper. This vertical extension, which forms the equivalent of a half-tube, is split by a vertical notch open upwards, the edges which delimit it extend freely under the rod and at a level situated above that of the axes. pivoting of the latter. By these provisions, when the rod pivots forward, the split part of the vertical extension can deform elastically without bracing and thus accompany in its movement the rod which straddles it.

As taught, the pivoting of the rod is therefore made possible on the condition of overcoming the elastic resistance of the vertical extension and therefore of its split part, which is also reflected in a relative approximation of the opposite edges which delimit the 'notch. The flexural capacity of the vertical extension consequently determines the flexural characteristics of the shoe. Now, the vertical extension being obtained in one piece with the shell base, it is the nature of the material constituting the shell base which, ultimately, predisposes the shoe to be more or less flexible, that is to say that is, which gives it its initial flexibility.

Given that the shell base of this type of shoe, like the generality of so-called "variable volume" shoes, must moreover be adjusted on the foot using tightening devices which modify its wrapping, the known solution to obtain an optimum initial flexibility suitable for each region concerned of the shoe therefore consists, from a given material, most often of plastic, also playing on the thickness of the wall of the shell base. For this purpose, the wall is made thin in the region of the closing flaps of the shell base and significantly thicker in the region of the split part of the vertical extension as well as in the lower region extending to the outsole.

This design of shoes with variable volume makes it possible to achieve a good stiffness-flexibility compromise for a specific shoe model as long as one chooses a plastic material which is not too stiff because it would then be necessary to produce extremely thin walls, or even d 'excessive fineness, at the locations of the clamping devices, that is to say where the shell base must be adjusted on the user's foot such as the instep area. In fact, in an almost general way, it is a relatively flexible material which is usually used which makes it possible to define the different regions of the shell base in wall thicknesses which remain compatible with traditional plastic molding processes even if it means thickening the most stressed areas.

The shoes thus designed, that is to say with wall thickening, in particular on the slit part of the vertical extension, give ultimately relatively satisfaction on the functional level because the flexibility of the upper then results from a pulling effect on the dorsal area of the shell base without blocking during the whole period when the opposite edges of the notch remain free to approach. In addition, by doing so, the force that the user applies to the rod is distributed over a large wrapping surface extending over the entire lower front region of his leg, which avoids the localization of significant pressures. On the other hand, this design of shoes has the disadvantage of making them considerably heavier and of not allowing the development of a basic structure which can be common or even standard for several models of shoes for which flexibility characteristics are sought. different initial. Indeed, in such a perspective it is necessary to make, for each model, or for each initial level of flexibility sought, a specific shell base by playing on the choice of plastic material and / or by playing on the thickness of its wall.

Obviously, it is known to add and / or associate with the flexion slot of the shell base adjustment devices intended to modify the characteristics of initial flexibility that said slot is capable of providing for a specific shoe model. This is what is described in particular in the documents EP 666 036, EP 671133, EP 350 023 and DE G 9217 787.5 cited above.

More specifically, the shoe adjustment devices described in European documents EP 350 023, EP 666 036 and EP 671 133 operate on the opposite edges of the notch of the vertical extension coming from the shell base while that of the shoe described in a German document G 92 17 787.5 interacts directly between the upper and the shell base. Thus, the initial flexibility of the rod can very easily be modified and controlled as much in effort as in amplitude by simply playing on the value of the space left free between the opposite edges of the notch and / or on the height of the notch allowed to flex. Obviously, this last adjustment simultaneously causes a modification in the level of the forces to be produced since it modifies the height of the support of the rod on the split part of the vertical extension with respect to the connecting and pivot axes of the rod. . However, it emerges from these shoe constructions that obtaining the split vertical extension of a part with the shell base penalizes, again, this kind of shoe. Indeed, by intervening, for example, directly on the edges of the notch with the adjustment devices taught by the documents EP 350 023, EP 666 036 and EP 671 133, it can be seen that the stresses, in particular the pressures, are very high at the points of contact with the adjustable stops of these devices and that they cause rapid deterioration of the edges of the notch. This deterioration results from the fact that the available bearing surface is limited to that offered by the thickness of the wall of the vertical extension at the location of the notch and to that of the ends of the adjustable stops. Another reason comes from the fact that the elastic material constituting the vertical extension is the same as that of the shell base, that is to say relatively flexible to allow good stiffness-flexibility compromise while being compatible with traditional molding processes for plastic materials.

Obviously, in the case of the adjustment device described in the German document G 92 17 787.5, the drawback aroused does not arise because this adjustment device interacts directly between the rod and the shell base by using a tension adjustable spring. . On the other hand, this device extends over the dorsal zone of the shoe and consequently presents a significant bulk in this zone which must very often be relatively clear to leave room for systems for retaining and / or fixing the shoe on sports equipment such as on skis for example. In addition, this device proves to be relatively complicated because it implements numerous mechanical parts.

In any event, it is clear that whatever adjustment devices are used on this kind of shoe they can only be effective in the sense of making the shoe less flexible than it is initially by reducing the forward bending capacity of its rod and / or by increasing the level of forces to be produced on the latter to cause it to flex. The shoe adjustment devices described above therefore do not avoid having to provide a shell base and / or a "shell-shell base" structure specific to each shoe model, that is to say specific to each desired initial level of flexibility.

Document US Pat. No. 5,353,528 presents a ski boot with rear entry equipped with an energy flap placed at the rear of the boot between the bottom of the shell and the rear spoiler.

The present invention proposes to overcome the drawbacks of the aforementioned shoes in a very simple and effective manner while retaining the advantages provided by the realization of a vertical split extension in the dorsal area of the shell base. An object of the invention is in particular to allow the realization of a basic structure of the shell of a shoe which is common and / or standard for several models of shoes which must have differentiated initial flexibility characteristics. Another object is to produce a light shoe which, while being obtained from a relatively flexible plastic material to ensure optimum adjustment and support of the user's foot, can provide, if necessary, great initial resistance to bending the rod forward. The object of the invention is also not to appreciably modify the external volume of the shell of the shoe by prominent parts.

The objects of the invention are achieved by the provision of a ski boot as claimed in claim 1.

By these characteristics, the flexible strip constitutes an extension of the shell base equivalent in its function to a split vertical extension which would have come in one piece with it but which has the advantage of being able to be produced in a material different from that of the hull base. Consequently, depending on whether the material chosen for this flexible strip is more or less resistant to bending, the flexibility of the shoe is modified either in the direction of decreasing it or in the direction of increasing it. The flexible strip therefore makes it possible to determine the initial basic flexibility which is desired for a shoe model without being dependent on the choice of material used for the shell base. It also makes it possible to stiffen the wall for the shell base over the area where it is attached and rigidly fixed, without affecting the flexibility it gives to the upper of the shoe.

Obviously, thanks to this independence of production of the means determining the initial flexibility of the shoe, it is easy to design the shell, including the shell base, in a plastic material best suited to ensure the function of adjusting and maintaining the foot in the shoe without having to provide excessive thicknesses at least in the areas of the latter which are stressed when bending the upper forward. The flexing means according to the invention thus makes it possible to design a basic structure of the shoe, "shell-to-rod base" or shell base only, which is common, until the time of final assembly, to several models of shoes . Indeed, it suffices in this perspective to provide a range of more or less flexible bands to make as many models of shoes which have different initial flexibility characteristics. To this end, despite the fact that the flexible strip can be fixed using any known means such as, for example, welding, riveting, gluing, bolting, etc., preference is given to the means of most easily removable assembly; by this choice, an adaptation of the flexibility of the shoe is subsequently made to its final assembly without having to destroy, even partially, the assembly means.

Still, still thanks to this independence of embodiment of the means intended to give the shoe its characteristics of initial flexibility, it is possible to choose a material having high mechanical characteristics capable of preventing the deterioration of the opposite edges of the notch if a adjustment device is provided to cooperate with them as in the examples of the shoes described in documents EP 671 133, EP 350 023 and EP 666 036 and described above.

The flexible strip which constitutes the means intended to determine the flexibility of the rod is in the form of a relatively thin piece which closely follows at least a portion of the dorsal region of the shell base and which extends laterally on the sides of the latter as far as the area of the connecting and pivot axes of the rod. The flexible band thus produced integrates perfectly into the external volume of the shell and surrounds approximately the entire region corresponding to the ankle of the user, leaving free the area of the instep where, in a conventional manner, the base of shell must, on the one hand, allow passage at the foot of the user during putting on and taking off, and on the other hand, be particularly well adjusted at the foot of the user to hold it without injuring it while allowing the rod to bend forward.

According to one embodiment of the invention, the flexible strip is obtained with at least one lateral extension which extends over a side of the shell base in the direction of the anterior zone thereof and beyond the axis of rod connection and pivoting. This extension has a slide in which a movable cursor is adjustable in translation.

This cursor is provided with a shoulder which projects in relation to the corresponding lateral lower edge of the rod and the slide is oriented approximately parallel to this lateral lower edge. By these arrangements, the rod is more or less hampered in pivoting, towards the front, by means of the slider, and this, in addition to the elastic resistance which the split portion of the flexible strip opposes to it. In fact, these provisions make the shoe more or less stiff as a whole because the upper can almost no longer bend forward if it is only on the condition of being able to deform elastically between the support of its lower edge. side on the cursor and its pivot axes.

Obviously, the slide of the lateral extension of the flexible strip can be oriented, from the level of the connecting axes of the rod, diverging from the lower lateral edge of the latter. In this case of construction, the upper can then flex forwards in contrast to the opposite elastic resistance in the dorsal area of the shoe by the flexible split strip, until it finds support on the slider, which is equipped with the slide. From this stop position where the rod can no longer pivot on its axes, it is the elastic deformation capacity of the rod which plays to allow the continuation of a forward movement. Still, the slide can itself be provided in order to be able to deform elastically under the effect of a force applied to the slider and directed forwards via the lateral lower edge of the rod. To this end, the slide may include a flexible portion located between its ends which define its length, fastening elements which may advantageously be located at the location of these ends. In this case, the level of forces to be produced on the rod to cause it to flex forward is a function of the elastic resistance opposed by the notched part of the flexible strip and of the elastic resistance of the slide. The flexing means, the flexible band, is thus able, under a small volume, to offer an extremely high overall elastic resistance because the flexibility of the rod towards the front results at the same time from a pulling effect on the dorsal zone. of the shell base and of a pushing effect on the anterior zone of the latter, on at least one of its flanks.

According to a construction detail of the flexible strip constituting the means intended to determine the flexibility characteristics of the upper relative to the shell base, this is obtained in the dorsal region of the shoe with a rim which projects towards the outside of the shoe and against which the upper is abutted by its rear lower edge. The shoe thus constructed has a upper only authorized to flex forward from the mounting position. It goes without saying that the height position of the rim in the dorsal region of the shell base can be determined according to several values depending on the inclination which it is desired to impose on the rod in its mounting position resting on the 'back.

In order to integrate as flexibly as possible into the overall volume of the shoe the flexing means, ie the flexible band, the shell base of the shoe is preferably made with a housing which extends at least over the entire area where the flexible strip covers it so that it can take place there.

The description which follows with reference to the appended schematic drawings illustrates an exemplary embodiment of the invention.

Figure 1 shows, in side elevation and in partial section, a shell shoe provided with a flexing means intended to determine the flexibility characteristics of the upper.

Figure 2 illustrates, seen in perspective, the flexing means of Figure 1 with the outline of the shoe.

FIG. 3 represents, in perspective view, the shell base of the shoe of FIGS. 1 and 2.

Figure 4 shows, along the section line IV-IV of Figure 1, how the upper of the shoe cooperates with a slider slide which is provided with the bending piece.

The shoe shown schematically in Figure 1 by way of example is of the type with front entry and variable volume. It has a shell 2 consisting of a rod 12 and a shell base 22 provided with a sole 5, the constituent parts 12-22 of the shell 2 being pivotally connected to each other by means of axes 32 connecting and pivoting preferably located in a region corresponding approximately to that of the ankle joint of the foot of the user (not shown). In this type of shoe, the shoeing-heaving is traditionally carried out by opening the upper front part 1 of the shell 2 to allow the passage of the foot of the user, and the adjustment on the foot of the latter results from a deformation of the shell 2; more precisely, this deformation is caused in a conventional manner using clamping devices 3 which pull on transverse flaps 4, 4 ′, which extend the wall of the shell base 22 and of the rod 12, these flaps 4, 4 ', ensuring the proper closing of the shell 2. In order to guarantee a certain seal and allow the rod 12 to flex relative to the shell base 22 by pivoting on the axes 32, these constituent parts 12-22 of the shell 2 overlap partially in an area which is preferably located approximately on the region corresponding to the ankle of the user and are provided in this area with relatively flexible and thin walls; the rod 12 can thus easily flex relative to the shell base 22 because these flexible and thin walls oppose only a very low elastic resistance. According to a characteristic of the invention, a flexing means 7 intended to determine the flexibility characteristics of the shoe is integrated in the dorsal zone 8 thereof. This means 7 is for this purpose sandwiched between the rod 12 and the shell base 22 on which it is attached and rigidly fixed, for example, by assembly means 33 such as rivets or bolts. The flexing means 7 is formed by a relatively thin flexible strip which is split over a portion of its length by a vertical notch 17 open upwards so that the edges 17 'which delimit it extend freely under the rod 12 and spaced from the shell base 22. This vertical notch 17 is preferably positioned in correspondence with the dorsal zone 8 of the shoe so that the resistance to flexion which the flexible strip 7 can oppose when the upper 12 is urged to pivot forward either approximately centered relative to the pivot axes 32 thereof. According to certain details, the flexible strip 7 closely follows at least a portion 16 of the shell base 22, located in the dorsal zone 8 of the shoe, and then extends laterally on the sides 22 'of the latter by two extensions 23 and 26 up to the region of the pivot axes 32 where it is fixed using the assembly means 33, leaving free the anterior zone 9 corresponding to the instep. More specifically, one, 23, of its extensions is provided, beyond the pivot axis 32 with a slide 24 in which a slider 25 slides. This slide 24 is fixed at these two ends 24 'on the shell base 22 by means of assembly means 33 and oriented parallel to the lateral lower edge 13 of the rod 12 which is in correspondence, and the slider 25 has a shoulder 25 ′ which is projecting from -vis this edge 13. By these provisions, the rod 12 is prevented from pivoting forward and it is its only capacity for elastic deformation which then plays to allow movement forward

Advantageously, the cursor 25 is adjustable in translation in the slide 24 and immobilizable in position by means of a succession of nesting cavities 30 produced on an edge of the slide and with which cooperate a boss 31 with which the cursor is provided. 25, as visible in particular in FIG. 4. Thus, by varying the position of the cursor 25 relative to the pivot axis 32 of the rod 12, the position of the fulcrum forwards towards the front of the rod is correspondingly modified. 12 and therefore its lever arm. In fact, the flexing means 7 thus arranged constitutes an adjustable means of stiffening the shoe allowing the upper 12 to deform more or less depending on the position of the cursor 25. Of course, by construction, the flexing means 7 also has a function of strengthening the shell base 22 at the point where it is most stressed by the rod 12, that is to say in the dorsal area 8 where there is overlap.

In order to integrate the flexing means 7, ie the flexible strip, into the overall volume of the shoe, the shell base 22, illustrated in FIG. 3, is produced with a housing 35 in which said means takes place there. . This housing 35 preferably extends at least over the area where the flexing means 7 covers it and its outline, as in the present embodiment, is advantageously contiguous to that of the flexing means 7. By doing so, the slide 24 is embedded on the base of the shell 22 without any possibility of bending between its assembly means 33 fixing it to the latter.

Obviously, in the case where a certain flexibility is desired, in particular to give a little more flexibility to the rod 12 when it rests on the cursor 25, a portion 27 of the slide 24 which is located between its two ends. 24 'which delimit it can be provided flexible. To this end, the contour of the housing 35 produced in the wall of the shell base 22 is then provided at the location of the slide 24, relatively larger than the latter so that its portion 27 can flex between these two ends 24 ' .

According to a construction detail of the flexing means 7, the latter is obtained with a flange 19 which projects outwards from the dorsal region of the shoe and against which the upper 12 is abutted by its rear lower edge 13 ' . The rod 12 is thus prevented from tilting backwards from the moment it bears on the rim 19. In fact, thanks to the elastic thrust edges 17 ′ of the notch 17 on the wall of the rod 12 the latter is urged and permanently urged against this flange 19.

Claims (7)

1. Ski boot of the front entry type with variable volume having a shell (2) constituted of an upper (12) and a shell base (22) that overlap at least partially in the area corresponding to the dorsal zone (8) of the boot, the upper (12) being connected to the shell base (22) by means of pivot axes (32), the boot also having a bending means (7) formed by a flexible band (7) that closely hugs at least a portion of the shell base (22) in the dorsal zone (8) of the boot and which then extends laterally on the sides (22') of the shell base (22) up to the zone of the pivot axes (32) of the upper (12), this bending means being furthermore partially sandwiched between the upper (12) and the shell base (22) on which it is rigidly attached and fixed in a non-pivoting manner, the flexible band (7) being split over a portion of its length by a vertical slot (17) that is open toward the top and positioned for extending vertically in the dorsal zone (8) of the boot, and whose edges (17') demarcating it extend freely under the upper (12).
2. Boot according to claim 1, characterized in that the flexible band (7) is obtained with at least one lateral extension (23) (26) that extends over one side (22') of the shell base (22) beyond the pivot axis (32) of the upper (12), this extension (23) being provided with a slide (24) in which a mobile cursor (25), adjustable in translation, has a shoulder (25') projecting opposite the corresponding lateral lower edge (13) of the upper (12).
3. Boot according to claim 2, characterized in that the slide (24) comprises a flexible portion (27) located between its ends (24') that delineate its length.
4. Boot according to any of claims 1-3, characterized in that the flexible band is obtained with a shoulder (19) that projects outwardly from the dorsal zone (8) of the boot and against which the upper (12) is mounted in abutment by its back lower edge (13').
5. Boot according to any of claims 1-4, characterized in that the shell base (22) is obtained with a hollowed housing (35) that extends at least along the entire zone where the flexible band (7) covers it.
6. Boot according to any of claims 1-5, characterized in that the flexible band (7) is fixed on the shell base (22) by means of assembly means (33) that can be disassembled without destruction.
7. Boot according to any of claims 1-6, characterized in that the flexible band (7) is obtained from a material that is different from that of the shell base (22).