WO1997036509A1

WO1997036509A1 - Shoe sole with a flexible arch support, and shoe provided therewith

Info

Publication number: WO1997036509A1
Application number: PCT/FR1997/000530
Authority: WO
Inventors: Philippe Freychat; Nicolas Bouche; Christophe Montavon; Eric Caille; Gaël Brivet
Original assignee: Decathlon S.A.
Priority date: 1996-03-29
Filing date: 1997-03-25
Publication date: 1997-10-09
Also published as: FR2746605A1; HUP9902422A2; FR2746605B1; DE69703262D1; PL329131A1; ES2152641T3; ATE196833T1; BR9708467A; AR006368A1; EP0797937A1; CN1215313A; CZ313498A3; EP0797937B1

Abstract

A sole for a shoe, particularly a sports shoe, comprising a front portion (3) and a rear portion (4) for the forefoot and the heel respectively, as well as an intermediate portion (5) with a reduced width (l) between the front (3) and rear (4) portions. The sole further comprises an arched portion (2) that contacts the arch of the user's foot and rises gradually from the intermediate (5), front (3) and rear (4) portions up to a predetermined height h above the plane of the lower surfaces of said portions (5, 3, 4). The arched (2) and intermediate (5) portions are made of flexible material so that when the arched portion is compressed and its height h is accordingly reduced, the front portion (3) is pivoted outwards, whereas when the front portion (3) is pivoted inwards (6), said arched portion is raised.

Description

SOLE FOR A SHOE WITH A DEFORMABLE ARCH AND A SHOE EQUIPPED WITH SUCH SOLE

The present invention relates to a sole for a shoe, in particular a sports shoe as well as a shoe equipped with such a sole. When walking, running or jumping, the individual's foot undergoes anatomical changes which are due to the joints existing between the twenty-six bones making up the human foot and grouped into four functional groups, namely the posterior tarsus, the anterior tarsus, metatarsals and phalanges. The movements of the different parts of the foot were studied during each phase of a running or walking cycle. At the end of the aerial phase, just before the impact of the heel on the ground, the foot is in slight dorsal flexion, inverted, with external tibial rotation. From the impact of the heel on the ground, the foot pronates at the same time as a knee flexion and an internal leg rotation are performed. The caicalean eversion unblocks the arch of the foot and the foot can adapt to the terrain and absorb the shock wave. The foot is then flat on the ground, supporting the total load of the individual, in eversion and abduction while the opposite member performs a pendulum movement from back to front. Then follows the propulsion phase which begins from the moment the heel takes off from the ground and lasts until the end of the support. During this propulsion phase, the relief of the heel and the increasing tension of the sural triceps and plantar fascia trigger an inversion of the foot, plantar flexion and adduction. The foot therefore goes into supination, with external rotation of the leg, which accompanies the extension of the knee and the hip for pushing. Finally, during the aerial phase, a transient passage in slight pronation allows the trajectory of the foot to be maintained before returning to the initial supination preceding the next press.

We understand why shoes, in particular sports shoes, can show wear or deformation, due to the varied and repetitive movements of the different parts of the foot. It has already been proposed to produce soles which allow a certain mobility of their front part on which the forefoot rests relative to their rear part on which the heel rests, in particular by the German utility model N ^β 1,886,439 by reducing the width of the intermediate part of the sole between the front and rear parts or by document FR.1.139.044 by arranging in this intermediate part lateral recesses in which are housed inserts made of softer and more elastic materials than that of the first sole and / or the outsole. However, according to the applicant, shoes equipped with such soles cannot provide the user with all the desirable comfort since the relative deformation of the front part with respect to the rear part of the shoe is always caused by the application of the foot. which abuts on the upper of the shoe. Certainly the comfort of the user is significantly improved compared to the shoe whose sole is not at all deformable. However, there remains the drawback of friction between the foot and the upper, in particular when it comes to sports shoes, in particular long-distance runners or walkers.

The object of the present invention is to provide a shoe sole which overcomes the aforementioned drawback.

This object is perfectly achieved by the shoe sole of the invention which comprises, in a known manner, a front part and a rear part intended to receive the forefoot and the heel respectively and an intermediate part of reduced width between the front parts and back. Typically this sole further comprises a vaulted part which is intended to be in contact with the internal arch of the user, arched part which is in progressive elevation from the intermediate, front and rear parts to a given height h , above the plane of the lower faces of said parts. In addition the arched and intermediate parts are made of deformable materials so that a crushing of the arched part, reducing the height of the elevation of this, causes an external pivoting of the front part and an elongation of the sole and that an internal pivoting of the front part causes an elevation of the arched part and a shortening of the sole. Thus according to the general concept of the present invention, the arched part of the sole constitutes a sort of bellows which is constantly in contact with the arch of the user and which is able to follow the movements in height thereof, said movements correlatively causing the internal and external pivoting of the front part relative to the rear part, along a pivot axis which is at the level of the intermediate part and which is therefore offset laterally relative to the longitudinal axis of the sole; it is this offset of the axis which is at the origin of the elongation of the sole during the external pivoting and of its shortening during the internal pivoting. Unlike the soles known to the applicant, the sole according to the present invention plays an active role in the relative mobility of the front and rear parts thanks to the action of the arch on the deformable arched part of the sole.

Preferably, the difference in height of the arched part between the external pivoting and the internal pivoting is of the order of 15mm.

Advantageously, the vaulted part is either a microcellular foam of density between 0.15 and 1, 3, for example made of polyurethane, ethyl vinyl acetate or rubber.

Preferably, the sole has a wear pad which is attached at least under the front and rear parts and preferably under only the front, rear and intermediate parts.

For the protection of the vaulted part, on the underside of the latter can be arranged wear flanges, in particular in the same deformable material. In a preferred embodiment, the front, rear, intermediate and arched parts of the sole form an assembly monobloc made of the same deformable material. In this case, advantageously, this one-piece assembly comprises under the arched part notches in relief constituting the protective wear flanges.

A shoe has already been proposed, in particular in document WO.95 / 06419, comprising a sole, the front part of which has a certain degree of mobility relative to the rear part and which comprises a stiffening element for this sole. According to this document, this stiffening element is shaped so as to allow the pivoting of the front part relative to the rear part around a vertical axis located substantially at the level of the calcaneo-cuboid joint, while preventing or limiting the front - rear bending of the sole as well as the torsion of its front part with respect to its rear part. According to the indications given in this document, it is under these conditions that the shoe provides the user with the best comfort while respecting the natural movements of the foot when walking, running or jumping.

In one embodiment, described in this prior document

WO.95 / 06419, the stiffening element is a flat, rigid element, having a narrowed shape in the central part and flared at its ends, having a longitudinal axis of symmetry, said stiffening element being arranged, thanks to a flexible housing , in a cavity in the sole. This cavity has a shape similar to that of the stiffening element, with a longitudinal axis of symmetry which is arranged along the longitudinal axis of the heel, when the shoe is at rest. The narrowed central part of the stiffening element is relatively adjusted inside the housing while on either side of the flared ends are reserved free spaces allowing the pivoting of the front and rear parts of the sole relative to the stiffening element. The applicant considered that it could be advantageous to integrate into the sole of his invention a stiffening element having the same functions as that of document WO.95 / O6419.

Thus, in known manner, the sole of the invention may include a stiffening element, flat and rigid, having a narrowed shape in the central part and flared at its ends and housed in a cavity dug in the sole.

Typically, in this case, the central part of the stiffening element is disposed at the level of the intermediate part of reduced width of the sole; more the stiffening element and the cavity which serves as its housing have an asymmetrical shape with a flared end which extends widely in the rear part of the sole, a side wall of the cavity substantially along the contour of the arched part of the sole.

Preferably in this case, the flared end disposed in the rear part of the sole is perfectly adjusted in the cavity, so that free spaces are formed on either side of the stiffening element only in the end flared from the cavity at the front of the sole.

Either the cavity is closed by a wear pad, which is attached under the front, rear and intermediate parts of the sole, in which case the stiffening element is not visible.

Or, to make the stiffening element visible, the cavity is closed by a transparent plastic and the wear pad has a window at said plastic. As provided for in document WO.95 / 06419, the stiffening element can itself be housed in a plastic, transparent and deformable case, having the shape of the cavity and housed in an adjusted manner therein. In this case, the sole may include a wear pad made up of two separate parts, reported respectively under the front part and the rear part, each partially covering the plastic casing so as to leave visible in part the stiffening element.

It is another object of the invention to provide a shoe, in particular a sport shoe, equipped with a sole having the aforementioned characteristics and which comprises a rod covering the foot proper from of the contour of the sole and being equipped with lateral bellows, in particular elastic bellows, arranged substantially at the level of the intermediate part. The purpose of these bellows is to absorb the effects of pivoting of the upper caused by the corresponding pivoting of the sole. The present invention will be better understood on reading the description which will be given of a preferred embodiment of a sole with a deformable arched part and of a shoe equipped with such a sole, illustrated by the appended drawing in which :

Figure 1 is a bottom view of the sole, Figure 2 is a side view of the sole of Figure 1

Figure 3 is a sectional view of the sole of Figure 1 along the axis III-

III,

Figures 4,5 and 6 are bottom plan views illustrating the movements of the sole during use, Figures 7,8 and 9 are side views of the soles illustrated in Figures 4, 5 and 6 respectively, and FIG. 10 is a perspective view of a shoe fitted with a sole of the invention.

The sole 1 for shoe and in particular for sports shoe which is the subject of the invention is characterized in that it comprises a vaulted part 2 which is intended to be in contact with the arch of the user and which is in a deformable material capable of allowing this arch to substantially match the different configurations taken by the arch during different movements of the foot during the different phases of walking, running or jumping and to cause correlatively the external and internal pivoting of the front part of the sole relative to its rear part.

More precisely, as appears clearly on examining FIGS. 1 to 3 appended, the arched part is arranged between the front part 3 and the rear part 4 of the sole 1 intended to receive the forefoot and the heel of respectively. the user; she is also on the side of the party intermediate 5 which is the part of reduced width I between the front part 3 and the rear part 4 of the sole 1.

The arched part is in progressive elevation from the front, rear and intermediate parts to a determined height h above the plane formed by the lower faces 3a, 4a and 5a of the front 3, rear 4 and intermediate 5 parts of the sole. 1.

The whole of the sole 1, constituted by the arched part 2, the front part 3, the rear part 4 and the intermediate part 5 is a monobloc assembly formed in a deformable material, for example a micro-cellular foam preferably having a density between

0.15 and 1, 3 or a rubber.

Taking into account the reduced width I at the level of the intermediate part 5 and the deformability of the material constituting the arched part 2, one obtains by exerting vertical pressure on the arched part 2 a relative pivoting of the front parts 3 and rear 4 relative to a vertical axis 6 which is located substantially at the level of the calcaneo-cuboid articulation of the user, thanks to the creep of the material constituting the arched part.

In a specific embodiment, the microcellular foam constituting the entire sole 1 was an EVA foam (ethyl vinyl acetate) or possibly made of polyurethane.

In the example illustrated, the sole 1 is provided with a wear pad 7 covering the lower faces 3a, 4a and 5a of the front 3, rear 4 and intermediate parts 5, but not covering the lower face 2a of the part vaulted 2.

The wear pad could possibly also cover the underside of the arched part, provided that it does not substantially alter the deformability properties which are required in the context of the present invention. This wear pad 7 is, conventionally, in particular made of rubber. The protection of the lower face 2a of the vaulted part 2 can be obtained by forming therein protective tubes 8 which consist of notches formed in the material of this vaulted part 2. In the example illustrated, the part intermediate 5 has a width which is variable in the thickness of the sole, being the smallest (I) at the level of the lower face 5a of the sole. This arrangement appears clearly in FIG. 3. The rounding of the upright 21 opposite the arched part 2 makes it possible to avoid the phenomena of buckling of the material constituting the intermediate part 5 during pivoting along the axis 6.

In order to provide the sole 1 with relative rigidity in front and rear bending, that is to say along a horizontal transverse axis 9, and in torsion of its front part 3 relative to its rear part 4, c that is to say around a longitudinal axis 10, the sole 1 is equipped with a stiffening element 11 which is housed in a cavity 12 formed in the lower face of the intermediate part 5 and partially of the front parts 3 and rear 4.

The stiffening element 11 is a flat, rigid element, which has a narrowed shape in its central part 13 and which widens towards its ends respectively 14 and 15 in the front 3 and rear 4 parts of the sole.

As appears on examining FIG. 1, the cavity 12 has a side wall 12a which runs along and is substantially parallel to the edge 2a of connection of the arched part 2 with the front 3, intermediate 5 and rear 4 parts. The walls ends 12b of the cavity 12, corresponding to the flared ends of the latter are curved, with a concave shape of constant curve, substantially centered on the pivot axis 6.

It should be noted that this pivot axis 6 is located along the narrowest width I of the intermediate part 5 of the sole 1. Taking into account the presence of the arched part 2 and the offset positioning of the pivot axis 6, the cavity 12 and the element of stiffening 11 are asymmetrical, with their flared ends which are not arranged in the extension of one another but which extend in the front 3 and rear 4 parts so as to occupy a large portion of the width thereof. ci, which favors the torsional rigidity of the sole 1.

The stiffening element 11 is in the example illustrated, adjusted exactly in the cavity 12 at its central part 13 and its flared end 15 opening into the rear part 4 of the sole 1. On the other hand its flared part 14 opening in the front part 3 of the sole 1 has a less pronounced flaring than that of the cavity so that there are free spaces 16 and 17 on either side of the stiffening element 11 in the end of the cavity 12 formed in the front part 3 of the sole 1.

These free spaces 16, 17 exist when the sole 1 is at rest, with the weight of the user distributed naturally over all of the parts of this sole 1 and that of the other foot.

Figures 4 to 9 illustrate the behavior of the sole 1 which has just been described during natural movements of the foot during the various phases of walking, running or jumping. We find in Figures 5 and 8 the arrangement which had been illustrated in Figures 1 and 2, when the user is at rest, with his feet which rest naturally on all of the parts of the two soles 1. This phase is characterized by a elevation of the arched part 2 by a height h and the existence of the free spaces 16, 17 on either side of the flared end 14 of the stiffening element 11.

Figures 4 and 7 show the configuration of the sole 1 after the impact of the heel on the ground, when the foot is flat with the full load of the weight of the individual distributed only on this foot, while the opposite member performs his pendulum movement from back to front. In this case, there is a crushing of the arch of the foot which correlatively causes the crushing of the arched part 2 of the sole. 1, reducing the elevation thereof to a height l ^.

This flattening of the arched part was carried out gradually after the impact of the heel which locked in position the rear part 4 of the sole 1. By flattening, the arched part 2 pushed back the front part 5 3, causing that -ci in an external pivot, according to arrow F, centered on the axis 6. This pivoting is made possible thanks to the deformability of the material of the intermediate part 5 and the reduced width I thereof.

The flattening of the arched part 2 causes at the same time a relative elongation of the sole 1 whose length L ₀ is greater than the length L of the sole at rest illustrated in FIGS. 5 and 8.

This result is entirely consistent with the natural deformation of the foot, which undergoes elongation during this phase of the cycle. There is therefore no relative movement between the foot and the sole 1 during the

Passage between the rest position of FIGS. 5 and 8 and the position which has just been described and illustrated in FIGS. 4 and 7. The external pivoting according to arrow F of the front part 3 of the sole 1 is not prevented by the presence of the stiffening element 11. Indeed during this pivoting relative to the axis 6, the flared end of the cavity 12 located in the part

20 before 3 also pivots according to arrow F1, while the stiffening element remains strictly in the same position. This pivoting of the cavity 12 simply leads to the reduction or even the elimination of the free space 17 between the stiffening element 14 and the side wall 12a adjoining the arched part 2.

25 Figures 6 and 9 illustrate the movement of the foot during the propulsion phase, that is to say when the heel takes off from the ground until the end of the support and entry into the phase air itself. During this phase, there is a plantar flexion, the arch of the foot deepening.

~ 3_2 This results in an elevation of the arched part 2 at a height h, greater than h. By rising, the arched part 3 causes H a traction on the front part 3 of the sole 1, causing the internal pivoting of the latter in the direction of the arrow G. As in the previous phase, and in the opposite direction, this pivoting is not prevented by the presence of the stiffening element 14 since it correlatively causes the pivoting of the flared end of the cavity 12 disposed in the front part 3 of the sole 1 in the direction of the arrow G _r II results in a reduction or even elimination free space 16 which was formed between the stiffening element 14 and the other side wall 12b of the cavity 12.

The heightening of the arched part 2 also leads to a reduction in the length L of the sole which is then less than the length L of the sole at rest. This decrease is consistent with the natural configuration of the foot during this phase.

Thus, by the action of the arch on the arched part of the sole 1 and the deformability of the intermediate part 5 allowing the external and internal pivoting of the front 3 and rear 4 parts relative to the axis 6, a sole which is able to perfectly fit the configuration of the foot during the various movements of the latter during walking, running or jumping, without particular friction or friction. For a medium-sized user, the elevation difference between the crushing and the elevation of the arched part is of the order of 15mm.

Of course the shoe 18 which is equipped with such a sole 1 comprises a rod 19 which covers the foot proper from the outline of the sole 1. So that the rod 19 is not an obstacle to the relative movement of the front parts 3 and rear 4 of the sole 1, it is provided that said rod 19 is equipped with bellows 20, in particular elastic, capable of absorbing the effects of pivoting according to the arrows F and G of the rod 19 caused by the corresponding pivotings of the sole 1 In the example illustrated, in particular by FIG. 3, the cavity 12 has been closed thanks to the application of the wear pad 7 on the front 3, rear 4 and intermediate 5 parts of the sole 1. This pad wear being generally rubber is not transparent or translucent and read the stiffening element 11 is therefore not visible.

If it is desired to make it visible to the user, it is possible to close the cavity 12 with a transparent plastic plate and create a window to the right of the said plate, either by using a one-piece wear pad. having a recessed opening acting as a window either by using a wear pad in two parts, one covering the front part and the other the rear part of the sole, the interval between the two parts forming the shoe d wear acting as a window. One can also consider using a transparent and deformable plastic housing which is fitted in the cavity 12, as taught in the prior document WO.95 / 06419. The above window will allow the stiffening element to be seen through one face of the case in question.

The present invention is not limited to the embodiment which has just been described by way of non-exhaustive example. The deformable sole with arched portion can be implemented with or without a stiffening element. In addition, the conformation and the function of the stiffening element may also be different from those which have just been described.

Claims

1. Sole for a shoe, in particular for a shoe, which comprises a front part (3) and a rear part (4) intended to receive the forefoot and the heel respectively and an intermediate part (5) of reduced width (I)

5 between the front (3) and rear (4) parts, characterized in that it further comprises a vaulted part (2) which is intended to be in contact with the internal arch of the user, and which is in progressive elevation from the intermediate (5), front (3) and rear (4) parts to a given height h, above the plane of the lower faces (5a,

10 3a, 4a) of said parts (5,3,4) and in that the arched (2) and intermediate (5) parts are made of deformable materials so that a crushing of the arched part, reducing the height (h ) of the elevation thereof, causes an external pivoting (F) of the front part (3) and that an internal pivoting (6) of the front part (3) causes an elevation of

15 the arched part.

2. Sole according to claim 1 characterized in that the difference in height of the arched part between the maximum external pivoting and the maximum internal pivoting is of the order of 15mm.

3. Sole according to one of claims 1 or 2 characterized in that the arched part (2) is a microcellular foam of density between

0.15 and 1, 3.

4. Sole according to one of claims 1 or 2 characterized in that the arched part (2) is made of rubber.

5. Sole according to one of claims 1 to 4 characterized in that it comprises a wear pad (7) which is attached at least under the front (3) and rear (4) parts.

6. Sole according to one of claims 1 to 5 characterized in that on the underside of the arched portion (2) are arranged wear flanges (8), in particular in the same deformable material.

^'30 7. Sole according to one of claims 1 to 6 characterized in that the front parts (3), rear (4), intermediate (5) and arched (2) form a monobloc assembly made of the same deformable material.

8. Sole according to one of claims 1 to 7 characterized in that it comprises a stiffening element (11), flat and rigid, having a narrowed shape in the central part (13) and flared at its ends (14,15 ) and housed in a cavity (12), characterized in that the central part (13) of the stiffening element (11) is disposed at the level of the intermediate part (5) of reduced width (I) and in that the stiffening element (11) and the cavity (12) which serves as its housing have an asymmetrical shape with a flared end which extends widely in the rear part (4) of the sole (1), a side wall ( 12a) of the cavity (12) substantially along the contour of the arched part (2).

9. Sole according to claim 8 characterized in that the flared end (15) of the stiffening element (11) disposed in the rear part (4) of the sole (1) is perfectly adjusted in the cavity (12) , so that free spaces (15,17) are formed on either side of the stiffening element (11) only in the flared end of the cavity (12) located at the front part ( 3) of the sole (1).

10. Sole according to claims 5 and 8 or 5 and 9 characterized in that the cavity (12) is closed by a transparent plastic and the wear pad (7) has a window at said plastic.

11. Sole according to claim 10 characterized in that the stiffening element is housed in a plastic housing, transparent and deformable, having the shape of the cavity and housed in an adjusted manner therein.

12. Shoe, in particular for sports, equipped with a sole according to one of claims 1 to 11, characterized in that it comprises a rod covering the foot proper from the contour of the sole and being equipped with lateral bellows , in particular elastic, arranged substantially at the level of the intermediate part.