EP0787440B1 - Sole for sports shoe - Google Patents

Abstract

The boot sole consists of a front section (2) and a rear section (3) which covers at least the underside of the heel. The rear section is rigid, having a module of elasticity of 260 MPa to 200 GPa, and extends forwards as far as the metatarsal-phalangeal joint zone (5). The front and rear sections of the sole overlap where they join over a length (L) in or to the rear of the metatarsal-phalangeal joint zone. The front section has a connector for attaching to a ski and its lengthwise median axis lies at an angle to that of the rear section, while the latter can be made in one piece with a heel stiffener on the upper.

Description

The present invention relates to a sole, in particular an outer sole for a shoe intended for sports requiring a rolling of the foot and / or sliding sports. It relates to also a method of manufacturing soles and a shoe provided with such a sole, respectively a shoe provided with a sole obtained by said manufacturing process.

As mentioned above, the present invention relates to sports requiring a course hiking, such as hiking, cross-country skiing, skating or classic skiing, downhill skiing, skiing telemark or snowshoeing. It also applies to board sports, such as ice skating, roller skating with wheels in line or not, snowboarding or skateboarding.

The above sports have in common requirements for footwear and particularly the sole, which requirements, at first glance, are incompatible.

In fact, all of these sports require movement from the user's center of gravity to the area of heel of the user's foot to the area of the natural flexion of the foot called metatarsophalangeal and vice versa. These movements are used for the direction and / or propulsion of the user's body, by example by means of an edge grip or equivalent operations, for example the pulse of movement practiced by striding with a roller skate, or cross-country skiing whatsoever in the classic or skating technique. Said displacements of the center of gravity are accompanied by a transmission of forces in the heel area, on the one hand, and in some cases flexion in said metatarsophalangeal flexion zone, on the other hand.

This results in the requirement of a good transmission of the forces, without losses by damping and parasitic deformation in the area at least between the heel and the metatarsophalangeal area, and therefore a requirement for rigidity of the sole in said area, often accompanied by the requirement of a process as natural as possible and therefore a associated flexibility of the sole in the metatarsophalangeal area.

Generally, the sole of sports shoes is formed in one piece. To vary the stiffness of the sole in the longitudinal direction, the thickness of the sole.

It is obvious that the integration of two different and even incompatible requirements in a room, namely the sole, can only be carried out at the expense of one of these requirements, namely the transmission of forces from the leg in the area between the heel and the area metatarsophalangeal and / or flexibility in the last area.

This results in the problem that said construction of the sole cannot satisfy all the requirements at the same time, and usually represents an unsatisfactory compromise between stiffness and flexibility.

Another problem relates to the manufacture of soles of the above type in one piece. These soles represent fairly high manufacturing costs because it is necessary to provide soles of specific and different lengths for all desired sizes. This results in the need to manufacture and store a large number of different soles or to cut the edges of a sole to make a size below. This last technique which is only used for outsoles is a waste of material and does not actually reduce the cost of production.

In document US 2,581,524, it is proposed to manufacture a midsole in two parts. However, said sole is intended for a leisure shoe and consequently the part rear, although it has a higher rigidity compared to the front part, remains flexible. Flexibility and a certain damping of the rear part are obtained by manufacturing it in materials like cork, sawdust or latex. The known sole of said document is therefore not capable to transmit efforts intended for example to take an edge, and therefore does not bring satisfactory solution to the problems described above.

Document US 1,428,356 shows the manufacture of a variable stiffness rubber sole.

The present invention aims to provide an improved sole to reconcile the contradictory requirements set out above and in particular an improved transmission of efforts and satisfactory flexibility of the sole while keeping production costs modest.

It also aims to propose a manufacturing process for a sole and a shoe provided with such a sole, respectively a shoe provided with a sole obtained by said process.

This object is achieved by the present invention in accordance with claim 1 in that it provides a shoe sole sports, comprising a front part and a rear part adjacent to the front part, the rear part covering at least the base of the heel area, characterized in that the rear part is rigid and substantially non-flexible, and has a modulus of elasticity between 260 MPa and 200 GPa, and that the rear part extends substantially to the so-called metatarsophalangeal flexion zone.

• prévision des parties avant et des parties arrières, qui sont respectivement identiques,
• orientation respectivement d'une partie avant et une partie arrière d'une manière alignée et chevauchante,
• détermination de la longueur de chevauchement en fonction de la pointure désirée,
• fixation de la partie avant par rapport à la partie arrière d'une manière solidaire, en formant ainsi une semelle d'une pointure désirée.

This object is also achieved by the present invention in accordance with claim 12 in that it provides a method of manufacturing a sports shoe sole according to any one of claims 1 to 12, the method comprising the following steps:

• prediction of the front and rear parts, which are respectively identical,
• orientation respectively of a front part and a rear part in an aligned and overlapping manner,
• determination of the overlap length as a function of the desired size,
• fixing the front part with respect to the rear part in an integral manner, thereby forming a sole of a desired size.

One of the ideas of the present invention is to provide a sole, in particular for a sports shoe, in two parts, a front part and a rear part adjacent to the front part.

According to one aspect of the present invention, the rear part is rigid and substantially non-flexible. This characteristic allows an efficient transmission of the forces coming from the user's leg and intended for the direction and / or propulsion of the body of the user, in particular by allowing a grip effective edge or to cooperate with a guidance system of the guide edge type in ski background.

The rigid rear part preferably extends in the zone between the heel and the zone metatarsophalangeal.

According to another aspect of the present invention, the two parts constituting the sole are overlap in and / or behind the metatarsophalangeal area in a junction area of length adjustable according to the size. The variation of the overlap length allows the manufacture of soles of different sizes on the basis of rear and front parts respectively identical, which considerably reduces production and storage costs by reducing the number of different parts to be manufactured.

• la figure 1 est une vue de côté d'une semelle d'un premier mode de réalisation de la présente invention,
• les figure 2a, 2b, sont des vues de côté d'une semelle selon un autre mode de réalisation de la présente invention,
• la figure 3 est une vue latérale d'une chaussure intégrant une semelle selon la présente invention,
• la figure 4 est une vue de dessous d'une semelle selon la présente invention.

In any case, the invention will be better understood and other characteristics thereof will be highlighted with the aid of the description which follows with reference to the appended schematic drawing showing, by way of nonlimiting example, several embodiments and in which:

• FIG. 1 is a side view of a sole of a first embodiment of the present invention,
• FIGS. 2a, 2b are side views of a sole according to another embodiment of the present invention,
• FIG. 3 is a side view of a shoe incorporating a sole according to the present invention,
• Figure 4 is a bottom view of a sole according to the present invention.

In Figure 1 is shown, schematically, an outer sole 1 intended for a shoe for cross-country skiing. However, the present invention also applies to all sports requiring transmission of forces from the user's leg and intended to the direction and / or propulsion of the user's body, in particular by an operation generally called edge grip. Examples of such sports disciplines are snowshoeing, cross-country skiing cross-country skiing, telemark skiing, hiking, snowboarding, ice skating or roller skating. For for reasons of simplicity, the following description will be made with reference to an outer sole intended for a shoe for cross-country skiing.

The sole 1 shown consists only of two parts 2, 3, which are adjacent one to the other. The construction of the sole 1 in two parts 2, 3 has the advantage that each part 2, 3, can be optimally designed according to the requirements respectively to be met and so that we can standardize production as we will see below. Freedom of design adapted to the particular requirements of each part 2, 3, independently of the other, is manifest for example by the possibility of a choice of different materials for part 2 before and part 3 back.

The rear part 3 extends in an area between the heel 4 and the area 5 of natural flexion called metatarsophalangeal.

As shown in Figure 1, the front part 2 of the sole 1 can be provided with a coupling element 6, such as a transverse axis, intended for coupling to a sliding support such as a cross-country ski not shown in the figure. This sliding support can be for example a ski whatever, an ice or roller skate, a snowboard or a snowshoe.

The rear part 3 is rigid and substantially non-flexible, which prevents losses by damping and parasitic deformations and allows better transmission of forces. The part rear 3 is made of any material guaranteeing almost flexibility of this part, and in particular in plastic of appropriate rigidity possibly reinforced by fibers such than glass or carbon, or metallic materials. This rear part, said to be rigid and substantially non-flexible, will have a elastic modulus between 260 MPa (Mega Pascal) and 200 GPa (Giga Pascal).

The front part 2, on the other hand, is preferably flexible, so as to allow an unwinding as natural as possible at the foot. This characteristic brings advantages with respect to use for sports such as cross-country skiing and hiking which require the area to run metatarsophalangeal of the foot.

This front part 2 will therefore preferably be made of plastic material having a flexibility appropriate for such an unwinding of the foot.

FIGS. 2a, 2b and 4 illustrate another embodiment of the present invention, and in particularly the method of manufacturing a sole according to the present invention.

As shown in Figures 2a, 2b; 4, the front part 2 and the rear part 3 of the sole 1 are overlap on a junction zone 5 of predetermined length "L", this length being adjustable in function of the shoe size as will be explained later. The junction or overlap area preferably extends into and / or behind the metatarsophalangeal flexion zone.

The extreme front limit of the overlapping zone 5 is formed by the axis "Δ" of articulation metatarsophalangeal. For reasons of progressiveness, comfort and to ensure better unfolding of the foot, without rupture, the overlapping zone 5 will preferably have a rigidity between those of the rear part 3 and the front part 2, or even a rigidity ranging gradually decreasing from its junction zone with the rear part, to its zone of junction with the front part for a perfect transition between these two extreme rigidities.

The method of manufacturing a sole according to the present invention will now be described in reference to Figures 2a, 2b.

First, as a first step, we plan several front parts 2 and several rear parts 3, which are respectively identical and have shapes corresponding substantially to the front part, respectively back of a human foot. However, the front 2 and / or rear 3 parts could also have a shape which requires a cutout for the finishing of the sole, namely a essentially rectangular shape.

The front parts 2 and the rear parts 3 can be formed from different materials. A choice of different materials also makes it easier to predict different stiffnesses, if desired, of the front pieces 2 compared to rear pieces 3.

As a second step, the front part 2 is aligned with respect to the rear part 3 in a way overlapping. In order to better correspond to the natural shape of a human foot and as it is illustrated in figure 4, the two parts 2, 3, can be aligned so that their axes longitudinal medians respectively M-M 'form an angle corresponding to an angle of the anatomy natural of the foot instead of being confused.

As a third step, the length respectively "L1, L2" is determined. (cf. Figures 2a, 2b) overlapping of the two parts 2, 3, so that the length respectively "P1, P2" (see Figures 2a, 2b) effective of the finished sole corresponds to the size desired of the sole, and therefore of the shoe which will be provided with such a sole. He is at note that the difference between two consecutive sizes is generally around 7mm. So, as the comparison of FIGS. 2a and 2b clearly illustrates, an overlap over a length "L1" more large makes it possible to obtain a sole with a shorter overall length "P1" and vice versa.

Preferably, a combination of certain identical front parts 2 and rear parts 3 identical is used for the manufacture of soles 1 whose length "P" corresponds to a range two to three sizes. This results in a reduction of half respectively by a third of the stock of parts 2, 3, different. Preferably, the variation of the overlapping length "L" is therefore equal to 14 and 21mm respectively.

It should be noted that, by varying the length "L" of overlap, it is possible, thanks to the present invention, to manufacture soles according to a system of continuous sizes, that is to say whose gradation between sizes is as fine as desired, based on a stock of parts 2, 3, constituting a coarse gradation system.

Preferably, it is the front part 2 which overlaps the rear part 3. This arrangement presents particularly advantages concerning the durability of the fixing of the front part 2 to the part rear 3, in particular when the front part 2 has a rigidity less than that of the part rear 3. As shown in FIGS. 2a, 2b, the front end 31 of the rear part 3 has in the longitudinal direction a decreasing bevel section, as well as the rear part 21 of the front part 2. This allows on the one hand, an overlap of the two parts without excess thickness in the transmission area, and secondly, to modulate the rigidity of the transmission area in the longitudinal direction.

As a fourth step, the front part 2 is fixed relative to the rear part 3 in a way solidarity. The preferred means of attachment are bonding and riveting. However, are suitable all the fixing means which allow a solid fixing, even under bending stresses or torsion and under variable temperatures.

As a result of the manufacturing process according to the present invention, a sole of a desired size in the whole range of possible sizes on the basis of parts 2, 3, available in more limited number of sizes.

Another embodiment of the present invention is shown in Figure 3.

According to the embodiment shown in Figure 3, the rear part 3 of the sole 1 forms a monobloc assembly with a rear buttress 8 of the shoe. Said buttress 8 surrounds the heel of the foot like a shell. Preferably, the buttress 8 extends from the heel area 4 to the natural metatarsophalangeal flexion zone 5. The holding effect, like a shell, of the heel of the foot by the monobloc assembly formed by the rear part 3 of the sole 1 and the buttress 8 is significantly improved when the buttress 8 is substantially rigid, and of a rigidity similar to that of the sole. Preferably, the rigidity of the buttress 8 is still less than the rigidity of the rear part 3 of the sole 1, which, as mentioned above, is substantially non-flexible.

The choice of stiffnesses of the buttress 8 and of the rear part 3 of the sole 1, respectively, can be carried out optimally by forming the buttress 8 and the rear part 3 of the sole 1 in the same material or on the contrary in different materials, while keeping the whole piece.

The preferred materials for the buttress 8 are leather or plastic materials possibly reinforced with inserts made of metallic materials or glass or carbon fibers.

Figure 4 is a bottom view showing a sole according to the present invention. As represented in the figure and in order to better correspond to the natural shape of a human foot, the two parts 2, 3, are aligned so that their median longitudinal axes M-M 'form a angle instead of being confused.

According to the embodiment shown in Figure 4, the front part 2 of the sole 1 has two zones 11, 12, which are preferably formed from different materials. Zone 11 is the overlapping area "L" of the front part 2 of the sole 1, as indicated previously this overlap zone 11 can extend forward up to the axis "Δ" of metatarsophalangeal joint. Preferably also, this overlap zone 11 has a rigidity greater than that of the front zone 12 and which is between the rigidity of the front part 2 and the rigidity of the rear part 3 of the sole 1. This construction allows improved fixing of the front part 2 to the rear part 3 by reducing the differences in rigidity between two adjacent parts in the area "L" overlap.

The heel zone 4 of the rear part 3 of the sole 1 is, in particular in the case of a Cross-country ski boot, provided with a guide groove 10 which is able to cooperate with a device in the form of an edge provided on a sliding support, for example a cross-country ski. Such a groove of guide also extends into the front part 2 of the sole. It should be noted that the rear part 3 of the sole 1 can, depending on its desired use, be provided with any cooperating system with a sliding support and / or a profile for improved hold and edge grip sole 1 on the ground.

The front part 2 of the sole 1 is, as already described, provided with a hooking element 6 for an articulated binding of the front of the boot provided with the sole 1 on a cross-country ski. Note that the front part 2 can also be provided with any other fixing system cooperating with a sliding or walking support, such as a snowboard or a snowshoe.

Of course, the previous description has been made by way of nonlimiting example. It is obvious for those skilled in the art that many modifications can be made without departing from the scope of the invention as defined by the claims. For example, a sole according to this invention may as well have more than two constituent parts, for example by dividing the rear part and / or the front part in several sub-parts.

Claims (19)

1. Outer sole for a sports boot, adapted to be coupled to a gliding support, comprising a front part (2) and a rear part (3) adjacent to the front part (2), the rear part (3) covering at least the base of the heel zone (4), characterized in that the rear part (3) is rigid and substantially non-flexible, and has a modulus of elasticity comprised between 260 Mpa and 200 Gpa, in that the rear part extends substantially up to the so-called metatarsal-phalangeal bending zone (5), and in that the front and rear parts (2, 3) are assembled together by overlapping.
2. Sole according to claim 1, characterized in that the two parts (2, 3) overlap (L) at least partially in or behind the so-called metatarsal-phalangeal bending zone (5).
3. Sole according to any of claims 1-2, characterized in that the front part (2) is flexible.
4. Sole according to claim 2 or 3, characterized in that the rear part (3) overlaps the front part (2).
5. Sole according to any of claims 1-4, characterized in that the front part (2) comprises at least one coupling element (6) for attachment to a gliding support.
6. Sole according to any of claims 1-5, characterized in that the median longitudinal axis (M) of the front part (2) forms an angle with the medial longitudinal axis (M') of the rear part (3).
7. Sole according to any of claims 1-6, characterized in that the rear part (3) forms a monoblock assembly with a stiffener (8) covering the heel.
8. Sole according to claim 7, characterized in that the rear part (3) of the outer sole (1) and the stiffener (8) have different rigidities.
9. Sole according to claim 8, characterized in that the rear part (3) of the sole (1) is more rigid than the stiffener (8).
10. Sole according to any of claims 7-9, characterized in that the rear part (3) of the sole (1) and the stiffener (8) are formed of different materials.
11. Sole according to any of claims 1-10, characterised in that it is an outer sole (1).
12. Method for manufacturing a sole (1) according to any of claims 1-11, the method comprising the following steps:

    providing the front parts (2) and the rear parts (3), which are respectively identical,

    orienting a front part (2) and a rear part (3), respectively, in an aligned and overlapping manner,

    determining the overlapping length (L) as a function of the desired size (P),

    affixedly attaching the front part (2) with respect to the rear part (3), thus forming a sole (1) with a desired size (P).
13. Method according to claim 12, characterized in that each rear part (3) is substantially rigid and non-flexible.
14. Method according to any of claims 12 or 13, characterized in that the front part (2) is glued to the rear part (3) in the overlapping zone (L).
15. Method according to any of claims 12 or 13, characterized in that the front part (2) is fixed to the rear part (3) by riveting.
16. Method according to any of claims 12-15, characterized in that the overlapping zone (L) is located in and/or behind the so-called metatarsal-phalangeal bending zone (5).
17. Method according to any of claims 12-16, characterized in that a stiffener (8) is affixedly attached to the rear part (3) of the sole (1) so as to form a monoblock assembly.
18. Method according to any of claims 12-17, characterized in that a front part (2) and a rear part (3) are mutually arranged such that their longitudinal axes (M-M') form an angle.
19. Sports boot, characterized in that it comprises a sole (1) according to any of claims 1-11.

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