EP0560698A1 - Sports shoe - Google Patents

Abstract

This shoe is of the type comprising a sole (3) whose front part has a certain degree of mobility with respect to the rear part and comprising an element (6) for stiffening the sole (3), this element being arranged substantially in its longitudinal axis. According to the invention, the stiffening element (6) is shaped so as to give relative stiffness to the sole (3) along a transverse horizontal axis, that is to say in front/rear flexure of the sole (3), and around the longitudinal axis of the latter, that is to say in torsion of its front part with respect to its rear part, whilst permitting its front part to pivot with respect to its rear part about a vertical axis located substantially at the level of the calcaneo-cuboid joint of the foot. <IMAGE>

Description

The present invention relates to a sports shoe, especially for walking, running or jumping.

Existing sports shoes can be painful for the user when they are used more or less intensively, and even generate phlyctenes, inflammation, bruising or other pathologies in specific places of the foot, know at the level of the internal face and in front part of the heel, at the level of the first and fifth metatarsal heads and at the level of the end of the toes.

Premature deformation or wear of the shoe at the corresponding places can be noticed, in particular on the shoes of long-distance runners.

To follow the natural evolutions of the shape of the foot, we know by the German utility model N ° 1 886 439 to make soles which laterally have marked camber towards the interior, so as to narrow the central part soles, to allow a certain mobility of their front part relative to their rear part.

Shoes comprising these soles have the drawbacks of being difficult to manufacture, not very comfortable and of ensuring only limited protection of the foot, due to these camber and lateral recesses.

It is also known from French Patent No. 1,139,044 to produce a sole comprising lateral recesses filled with softer and more elastic material than that of the first sole and / or the outsole. These inserts make it possible to remedy the aforementioned drawbacks, while preserving the total width of the sole, and reserve possibilities of twisting the sole as well along its longitudinal axis, that is to say in pivoting of the front part relative to the rear part of the sole around this axis, only along an axis which is transverse to it, that is to say in front-rear bending of the sole. However, this sole does not respond perfectly to the anatomical evolutions of the foot during sports activities and presents significant problems of wear of the inserts and of assembly of these to the sole.

Also known from German patent applications No. 39 27 617, No. 39 18 522 and European No. 0 278 094 a sole having lateral recesses and comprising a stiffening element disposed along the longitudinal axis of the sole, these recesses allowing the sole to be twisted along its longitudinal axis, that is to say the pivoting of the front part thereof relative to its rear part around this axis, while the stiffening element while allowing this torsion, limits the bending of the sole around a horizontal transverse axis and prevents the pivoting of the front part thereof relative to its rear part around a vertical axis.

Shoes fitted with such soles also prove not to respond perfectly to the anatomical evolution of the foot during sports activities and may present wear and assembly problems at the points of attachment of the stiffening element to the sole.

The present invention aims to remedy these drawbacks by providing a sports shoe providing perfect foot comfort in all circumstances, and in particular when the user is in motion, this shoe must, in addition, have perfect resistance to wear.

To this end, in the sports shoe according to the invention, which is of the type comprising a sole, the front part of which exhibits a certain degree of mobility relative to the rear part and comprising a stiffening element of the sole arranged substantially according to the longitudinal axis thereof, the stiffening element is shaped so as to impart relative rigidity to the sole along a horizontal transverse axis, that is to say in front-rear bending of the sole, and around the longitudinal axis thereof, that is to say in torsion of its front part relative to its rear part, while allowing the pivoting of its front part relative to its rear part about a vertical axis located approximately at the level of the calcaneo-cuboid joint of the foot. In addition, the side walls of the upper of the shoe have relative flexibility in a horizontal plane, substantially at the level of said articulation.

It appears that the angle normally formed at rest by the axis of the heel with the axis of the forefoot varies when the subject is moving, especially when walking, running or jumping . Relative to the rest position, there is a pivoting of these two parts of the foot in a horizontal plane and around a vertical axis passing substantially through the aforementioned articulation, this pivoting, the amplitude of which can reach approximately 15 °. on either side of the rest position, which can be done either outwards, according to a pronation movement, which is the case for the great majority of the population, or inwards, according to a movement of supine.

In fact, this phenomenon seems to have the role, on the one hand, by tending the plantar fascia, to stiffen the bony arch of the foot, which makes it possible to avoid its crushing and to absorb the shock of the foot against the ground. , and, on the other hand, to orient the plantar fascia so that the heel is placed substantially in the axis of the stroke, which makes it possible to optimize the grip and the transmission of the impulse.

The shoe according to the invention, thanks to its possibility of pivoting, can adapt to the deformation of the foot specific to each user and provides perfect comfort with moderate wear, even in case of intensive use.

In addition, it is necessary to combine this possibility of pivoting with a relative stiffening of the sole at the level of said articulation in flexion and in torsion, for obtaining a perfect comfort of the foot in the shoe.

Advantageously, the sole comprises two grooves arranged longitudinally on either side of the stiffening element, giving it flexibility in a horizontal plane necessary for the aforementioned pivoting, that is to say allowing the compression of its constituent material of the side towards which its front and rear parts pivot and the stretch of its constituent material on the opposite side, and this while retaining material along the lateral edges of the sole to provide support and protection for the foot at this location.

To promote this flexibility, the grooves are arranged in the upper face of the sole while the stiffening element is housed in a cavity formed in the lower part of the sole.

For the same purpose, the grooves have a shape curved towards the inside of the sole and the walls of the sole which delimit them externally comprise a plurality of notches arranged substantially perpendicular to them.

Advantageously, the stiffening element is contained in a housing made of relatively flexible material whose central part, centered on the pivot axis is narrowed and shaped to have a certain elastic flexibility in a horizontal plane, in order to be able to follow the pivoting of the front and rear parts of the sole around said axis, and the end parts of which are flared and have rigid side walls which the side walls of the stiffening element meet when the front and rear parts of the sole pivot, these side walls playing the role of stops limiting the pivoting of said front and rear parts of the sole. The housing is advantageously shaped so that its lateral walls allow the front and rear parts of the sole to pivot by substantially 15 ° on either side of the longitudinal axis of the sole.

The housing allows, in addition to constituting these stops, to protect the stiffening element, and participates in the elastic return of the front and rear parts of the sole as well as in the stiffening of the latter in bending and in torsion.

According to a preferred embodiment of the invention, the end walls of the housing have a concave shape of constant curvature substantially centered on the pivot axis of the front and rear parts of the sole, and the stiffening element has convex end walls with the same radius of curvature as the end walls of the housing, along which they slide when the front and rear parts of the sole pivot. Thus, perfect guidance of the stiffening element in its housing during said pivoting is achieved.

Preferably, the housing cover has two longitudinal wings capable of being engaged in complementary recesses arranged in the underside of the sole and of being covered by wear pads. In this way, the bonding surfaces are large, which allows a good solidity of the assembly.

In addition, the crampons of the sole wear pads are arranged in lines more or less concentric with the pivot axis of the front and rear parts of the sole, so that they always have edges substantially perpendicular to the axis of walking or running, regardless of the amplitude of the pivoting of the front and rear parts of the sole.

Anyway, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of nonlimiting example, a preferred embodiment of the sports shoe which it relates .

• Figure 1 is a perspective view;
• Figure 2 is an exploded perspective view in partial longitudinal section;
• Figure 3 is a bottom view with partial cutaway;
• Figure 4 is a sectional view along the line IV-IV of Figure 3;
• Figure 5 is a sectional view along the line V-V of Figure 4; and
• Figure 6 is a view similar to Figure 3, in a particular operating position.

The figures represent, from different angles, a sport shoe 1, in particular walking, running or jumping.

This shoe comprises two longitudinal grooves 2 arranged from the upper face of the sole 3 and a cavity 4 arranged in the lower face of the sole 3, between the grooves 2. This cavity 4 receives a housing 5 which contains an element 6 of stiffening of the sole 3.

The grooves 2 are located along the lateral edges of the sole 3. They are substantially centered on the axis of the calcaneo-cuboid joint of the foot and have a generally curved shape towards the interior of the sole 3.

The walls of the latter, which externally delimit the grooves 2, comprise a plurality of notches 7 arranged substantially perpendicular to them.

The cavity 4 is also substantially centered on the axis of the calcaneo-cuboid joint and has a narrowed shape in the central part and flared at its ends, whose lateral edges more or less follow the walls of the sole 3 which internally delimit the grooves 2.

The walls of the sole 3 delimiting the ends of the cavity 4 have a concave shape of constant curvature, substantially centered on the axis of the calcaneo-cuboid joint. Cavity 4 is further extended by two recesses 10 of less depth than it.

The housing 5 consists of a bottom 11 and a cover 12 of relatively flexible plastic material, in which the bottom 11 can be interlocked, this cover 12 having two longitudinal ears 13, of shape corresponding to that of the recesses 10.

The bottom 11 and the cover 12 have a shape which corresponds to that of the cavity 4, in which they can be inserted without play, the ears 13 of the cover 12 being positioned in the recesses 10.

At one of its ends, the bottom 11 of the housing 5 has a wall 15, arranged on its longitudinal median axis and projecting towards the interior of the housing 5.

The stiffening element 6 is made of rigid plastic and has a general shape which corresponds to that of the housing 5, except that the angle formed by the rectilinear side walls 6a of each of its flared ends is less than approximately 15 ° at the angle formed by the corresponding side walls 11a of the ends of the bottom 11, so that each aforementioned side wall 6a of the stiffening element 6 delimits, with the corresponding side wall 11a facing it, a space 20 in the form of a sector of a circle with an angle of approximately 7.5 °.

In addition, the stiffening element 6 has a notch 21 which engages around said projecting wall 15 of the housing 5, the shape of this notch 21 being such that it delimits between the stiffening element 6 and the projecting wall 15, two spaces 22 substantially in the form of a sector of a circle, each of which is at an angle of approximately 7.5 °.

The lateral walls of the upper of the shoe have, moreover, lateral inserts 23 of extensible material, giving them relative flexibility in a horizontal plane, substantially at the level of said articulation.

In addition, the shoe 1 may comprise a band 24 bearing under the midsole 3 at or near the pivoting zone and enclosing the instep, this band 24 being able to be stretched by the laces in order to clamp the shoe 1 and hold the sole 3 against the foot. The efficiency of shoe 1 is significantly increased thanks to this clamping.

In practice, the stiffening element 6 is inserted into the housing 5, and the latter, after closing, is put in place in the cavity 4, the rubber wear pads 25 of the sole 3, the cleats 26 of which are arranged along more or less concentric lines to the axis of the aforementioned calcaneo-cuboid joint, covering the ears 13 to achieve the final assembly of the assembly.

The latter gives relative rigidity to the sole 3 along a transverse horizontal axis, that is to say in front-rear bending of the sole 3, and around a longitudinal axis thereof, that is to say -tell in torsion of its front part relative to its rear part, while allowing, in combination with the grooves 2, the pivoting of the front part of the sole 3 relative to its rear part around a substantially coincident vertical axis with the axis of the calcaneo-cuboid joint of the foot, as shown in Figure 6.

This pivoting is made possible by the relative elastic flexibility of the housing 5 in the central part, by the grooves 2 and by the aforementioned spaces 20, 22 existing between the internal lateral walls 11a of the bottom 11 of the housing 5 and those 6a of the element. stiffening 6.

The grooves 2 allow, in effect, the compression of the constituent material of the sole on the side towards which the front and rear parts thereof pivot and the stretching of its constituent material on the opposite side, and this while retaining flexible material along the lateral edges of the sole 3 to provide support and protection for the foot at this location.

The curved shape of the grooves 2, their position in the upper part of the sole 3 while the housing 5 is located in the lower part thereof, and the notches 7 promote this flexibility.

The aforementioned spaces 20, 22 allow the housing 5 to follow the pivoting of the front and rear parts of the sole around the axis of the aforementioned articulation, the side walls 11a having the bottom 11 or the projecting wall 15 playing the role of limit stops for pivoting of the front and rear parts by an amplitude of the order of 15 ° on either side of the longitudinal axis of shoe 1.

The housing 5 also makes it possible to protect the stiffening element 6, and participates in the elastic return of the front and rear parts of the sole 3, as well as in the stiffening of these in flexion and in torsion.

In addition, the sliding of the convex side walls 6b of the ends of the stiffening element 6 against the corresponding concave walls of the ends of the bottom 11 allows perfect guidance of the stiffening element 6 in the housing 5 during pivoting.

Thus, the shoe according to the invention, thanks to its possibility of pivoting around the aforementioned axis, can adapt to the natural deformation of the foot during sports activities, while providing perfect comfort to the shoe at the level of the pivot axis, because the flexibility of the sole is obtained without making recesses in it limiting the protection of the foot. In addition, thanks to the continuity of its side walls, the sole 3 has a perfect visual appearance.

The studs 26 of the wear pads 25, thanks to their shape concentric with the pivot axis of the front and rear parts of the sole 3, have always edges substantially perpendicular to the axis of the step or the race, whatever the direction of pivoting of the front and rear parts of the sole 3.

The mounting as above of the stiffening element 6 in the sole 3 provides significant bonding surfaces which eliminate any risk of wear, and in particular of shearing of the sole 3 at the level of the attachment of the element 6 to that here, the housing 5 constituting an interface between the rigid material of the stiffening element 6 and that, flexible, of the sole 3.

It goes without saying of course that the invention is not limited to the embodiment of the shoe which it relates to, described above by way of example but that it embraces, on the contrary, all variants thereof. of achievement.

Thus, the sole could include a cavity housing a series of successive links articulated to each other in a horizontal plane in the manner of the vertebrae of a spine, but linked to each other rigidly in flexion in a vertical plane and in torsion , along the axis of the series, which would provide the aforementioned rigidity along the transverse and longitudinal axes mentioned above and the possibility of pivoting of its front and rear parts in a horizontal plane.

Claims (10)

1 - Sports shoe, of the type comprising a sole, the front part of which exhibits a certain degree of mobility relative to the rear part and comprising a stiffening element of the sole arranged substantially along its longitudinal axis, characterized in that the element stiffening (6) is shaped so as to impart relative rigidity to the sole (3) along a transverse horizontal axis, that is to say in front-rear bending of the sole (3), and around the longitudinal axis thereof, that is to say in torsion of its front part relative to its rear part, while allowing the pivoting of its front part relative to its rear part about a vertical axis located substantially at the calcaneo-cuboid articulation of the foot, shoe further characterized in that the lateral walls of its upper have relative flexibility in a horizontal plane, substantially at the level of said articulation. 2 - Shoe according to claim 1, characterized in that its sole (3) comprises two grooves (2) arranged longitudinally on either side of the stiffening element (6), while retaining material along the lateral edges of the sole (3). 3 - Shoe according to claim 2, characterized in that the grooves (2) are arranged in the upper face of the sole (3) while the stiffening element (6) is housed in a cavity (4) arranged in part bottom of the sole (3). 4 - Shoe according to claim 2 or claim 3, characterized in that the grooves (2) have a curved shape towards the inside of the sole (3). 5 - Shoe according to one of claims 2 to 4, characterized in that the walls of the sole (3) which delimit the grooves (2) externally comprise a plurality of notches (7) arranged substantially perpendicular to them. 6 - Shoe according to one of claims 1 to 5, characterized in that the stiffening element (6) is contained in a housing (5) of relatively flexible material, the central part of which is centered on the pivot axis, is narrowed and shaped to have a certain elastic flexibility in a horizontal plane, in order to be able to follow the pivoting of the front and rear parts of the sole (3) around said axis, and the end parts of which are flared and have side walls rigid (11a) that meet the side walls (6a) of the stiffening element (6) during the pivoting of the front and rear parts of the sole (3). 7 - Shoe according to claim 6, characterized in that the housing is shaped so that its side walls (11a) allow pivoting of the front and rear parts of the sole (3) at an amplitude of substantially 15 ° apart and on the other side of the longitudinal axis of the shoe (1). 8 - Shoe according to claim 6 or claim 7, characterized in that the end walls of the housing (5) have a concave shape of constant curvature substantially centered on the pivot axis of the front and rear parts of the sole ( 3), and the stiffening element (6) has convex end walls of the same radius of curvature as the end walls of the housing (5), along which they slide during the pivoting of the front and rear parts of the sole (3). 9 - Shoe according to one of claims 1 to 8, characterized in that its wear pads (25) include studs (26) arranged in lines more or less concentric with the axis of the calcaneo-cuboid joint . 10 - Shoe according to one of claims 1 to 9, characterized in that it comprises a band (24) bearing under the midsole (3) at or near the pivoting area and enclosing the instep , this strip (24) being able to be stretched in order to clamp the shoe (1) and to hold the sole (3) against the foot.

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