Patent Application
20140310982
The present disclosure relates to the technical field of shoe soles, in particular for sporting activities, and to shoes fitted with such soles, in particular shoe soles including a main shock-absorber part that extends in the hindfoot region and from the medial (inner) side towards the lateral (outer) side of said soles, the main shock-absorber part comprising top and bottom elements and a partition element that extends between said top and bottom elements so as to form at least two cavities, namely a medial cavity and a lateral cavity, that open out respectively to the medial side and to the lateral side of said soles.
Shoe soles, in particular for sporting activities, need to satisfy numerous requirements. They should be comfortable and stabilize the foot, in particular acting to decrease or even prevent supination and pronation tendencies during rolling of the foot when said foot is in contact with the ground. They should also absorb the energy generated by repeated impacts, mainly between the heel region and the ground, and they should recover as much of this energy as possible so as to propel the following movement. The purpose of these properties is to improve the performance of the user, while protecting in particular the spine from vibration resulting from impacts, and the ankle and knee joints, in particular from sprains and/or joint fatigue. Finally, they should be attractive and, in particular, they should highlight the functions of their various component elements.
US 2003/0061731 thus describes a shoe sole comprising top and bottom elements that form a main shock-absorber part and that form lateral and medial cavities that open out respectively to the lateral and medial sides in the hindfoot region, said top and bottom elements are joined together in the midfoot region. The top and bottom elements present intermediate portions that converge towards each other and thus define a partition that extends between said top and bottom elements along the middle axis of said sole. Medial and lateral shock-absorber elements are also arranged respectively in the medial and lateral cavities.
In US 2003/0061731, the contact interface has the drawback of centralizing the impact forces and thereby stiffening the intermediate portions of the top and bottom elements, and this can be uncomfortable, in particular with regard to the calcaneum (heel bone).
The purpose of the shoe sole of the present disclosure is to improve user comfort, to provide more shock absorption, to improve the distribution of impact forces in the sole and thus towards the foot, to comply better with the natural movement of the foot while rolling on the ground, in particular in terms of the user's weight and the type of foot roll (pronator, universal, or supinator).
The present disclosure mitigates the above-mentioned problems in full or in part in that, in a first aspect, it provides a shoe sole including a main shock-absorber part that extends in the hindfoot region and from the medial side towards the lateral side of said sole, said main shock-absorber part comprising top and bottom elements and a partition element having at least one portion with a longitudinal axis (P), said partition element extending between said top and bottom elements so as to form at least two cavities, namely a medial cavity and a lateral cavity that open out respectively to the medial side and to the lateral side of said sole.
Advantageously, the hind edges of the top and bottom elements include respective medial and lateral top regions and medial and lateral bottom regions arranged on either side of said axis (P), and the medial and lateral top regions extend in rectilinear manner respectively towards the lateral and medial bottom regions, so as to form an X-shaped structure with a longitudinal axis (t) that coincides with said axis (P).
The shoe sole presents a middle axis (S) that corresponds to the natural middle axis or axis of symmetry of the foot.
The X-shaped structure makes it possible to stiffen the partition element and thus, by a lever arm effect, to offset the shock-absorbing effects further towards the side regions of the top and bottom elements. The side regions of the top and bottom elements, and in particular of the top element, deform and thus improve the shock-absorption provided by the sole, by distributing it over a surface area that is greater than the partition element on its own.
The X-shaped structure also makes it possible to provide a top cavity that is defined by the top medial and lateral regions and that is suitable for receiving a top shock-absorber part. This arrangement improves the shock-absorption provided by the sole, in particular with regard to the calcaneum.
In the ambit of the present disclosure, the term “supinator-type stride” means any stride in which the foot bears initial on its medial hindfoot region while the foot is rolling against the ground. The term “universal- or pronator-type stride” should be understood as any stride in which the foot bears on its lateral hindfoot region while the foot is rolling against the ground, with this offset of the bearing area to the lateral hindfoot region relative to the middle axis (S) of the sole being more pronounced when the stride is of the pronator type.
In the ambit of the present disclosure, it is considered that the hindfoot region is the zone of the heel of the foot that extends as far as the midfoot region corresponding to the arch of the foot that extends as far as the forefoot region.
In a second aspect, preferably in combination with the first aspect of the present disclosure, the present disclosure also provides a shoe sole including a main shock-absorber part that extends in the hindfoot region and from the medial side towards the lateral side of said sole, said main shock-absorber part comprising top and bottom elements and a partition element having at least one portion with a longitudinal axis (P), said partition element extending between said top and bottom elements so as to form at least two cavities, namely a medial cavity and a lateral cavity that open out respectively to the medial side and to the lateral side of said sole.
Advantageously, said axis (P) intersects the middle axis (S) of said sole so as to form an angle alpha that is less than or equal to 45°, preferably less than or equal to 30°.
The angles alpha are given in absolute value and do not take trigonometric sign into account.
In any event, the angle alpha is greater than 0°, so the axis (P) thus never coincides with the middle axis (S) of the shoe sole.
The angle alpha is thus determined as a function of the user's weight and stride type (pronator, supinator, universal).
For a pronator- or universal-type stride, the angle alpha is less than or equal to 45°, preferably less than or equal to 20°. Since the pronator- and universal-type strides are similar, the angle alpha is substantially the same for both of them, for reasons of ease of manufacture.
For a supinator-type stride, the angle alpha is less than or equal to 45°, preferably lying in the range 20° to 45° inclusive.
This arrangement makes it possible to arrange the preferably-hind portion of the partition element, starting from the hind edge of the sole of the present disclosure, in a medial or lateral hindfoot region of the sole and not on the middle axis (S) of the sole, preferably in the medial hindfoot region of the sole. The medial and lateral hindfoot regions are arranged on either side of the middle axis (S) of the sole.
Preferably, said preferably hind portion of the partition element is arranged in the medial hindfoot region opposite from the lateral hindfoot region in which the foot of a user spontaneously bears against the ground depending on the user's pronator- or universal-type stride. Thus, for pronator- or universal-type strides, when the user's foot strikes the ground in the lateral hindfoot region, the sole of the present disclosure accompanies and guides the foot towards its medial hindfoot region. This arrangement thus makes it possible to place the medial hindfoot region of the foot in register with the lateral regions of the top and bottom elements that present the greatest amount of deformability since they do not have any hind portion of the partition element. The user's comfort is thus improved. For a supinator-type stride, in the minority compared to the more widespread universal- and pronator-type strides, said preferably-hind portion of the partition element, is also placed in the medial hindfoot region.
In a variant, the partition element follows a curvilinear path in the hindfoot region, said curvilinear path is preferably substantially symmetrical, about the middle axis (S) of the sole, to the path of the center of pressure of the foot during spontaneous rolling of the foot on the ground.
The partition element as a whole, thus including its hind portion, thus follows a curvilinear path that is opposite to the path followed by the foot during its natural and spontaneous rolling on the ground, so as to accompany and guide the foot during said rolling. This arrangement thus improves user comfort considerably. The impact forces are offset even more towards the top and bottom elements, which elements thus tend to converge towards each other on either side of the partition element.
This variant applies in particular to a path of the center of pressure of the foot corresponding to a pronator- or universal-type stride.
For supinator-type strides, the curvilinear path adopted is similar or identical to the curvilinear path used for pronator- or universal-type strides.
In particular, it should be observed that, in operation, the bottom face of the bottom element is covered entirely or in part by an anti-slip outsole that, while the foot is rolling on the ground, holds in place the bottom element that is in contact with the ground, so that the top element is essentially the only element to deform on either side of the partition element.
In a variant, the top element and the bottom element of the main shock-absorber part are joined together in the midfoot region.
In a variant, the main shock-absorber part is a single piece, preferably made of one or more thermoplastic polymers.
The main shock-absorber part is preferably obtained by molding.
In a variant, the top element comprises top medial and lateral regions defining the medial and lateral cavities in part, said top medial and lateral regions sloping towards said partition element.
In a variant, the bottom element comprises bottom medial and lateral regions defining the medial and lateral cavities in part, said bottom medial and lateral regions sloping towards said partition element.
Since the partition element is configured to cause the foot to pivot towards the middle axis (S) of the sole, the two above-mentioned variants make it possible to stabilize the partition element and to attenuate such pivoting.
In a variant, the lateral regions of the top and bottom elements are raised, at least in part, relative to the medial regions of the top and bottom elements.
This arrangement makes it possible to attenuate the force of the impact and the lever effect on the foot during the initial moments of the foot bearing against the ground, in particular for a pronator- or universal-type stride, which corresponds to the vast majority of types of stride.
In a variant, the partition element has an X-shaped structure.
The partition element, and not only its hind portion, is thus X-shaped, which accentuates the tendency of the sole of the present disclosure to lead the foot along the middle axis (S) of the sole, since the lever arm between the partition element and the medial and lateral portions of the top and bottom elements is accentuated. Specifically, if the partition element were to provide a contact area as large as the contact area described in US 2003/0061731, the lever arm would be smaller and the top element would tend to deform much less, which would cause the partition element to stiffen.
In a variant, the shoe sole of the present disclosure includes a top shock-absorber part having top and bottom faces and including, at least along part of its periphery, vertical rims that extend from its top face so as to form a housing for confining the heel of the foot.
The bottom face of the top shock-absorber part is configured so as to match closely with the top face of the top element of the main shock-absorber part, thereby forming a projection that is housed on said medial and lateral top regions of the top element.
Said projection thus performs the function of top shock-absorber part.
In a variant, said at least two cavities, namely a medial cavity and a lateral cavity, are empty.
The design of the sole of the present disclosure enables it to be used without any medial and/or lateral shock-absorber part made of foam, which improves its lifetime considerably. Specifically, it should be observed that, under the effect of repeated compression forces, foam materials no longer become filled with air and thus become stiff. Such foam materials thus no longer provide their primary function of shock absorption.
In a variant, the sole of the present disclosure includes one or more medial and/or lateral shock-absorber parts that are fastened in the medial and/or lateral cavity(ies), in particular by adhesive-bonding or by overmolding while the main shock-absorber part is being molded.
The medial and/or lateral shock-absorber part(s) is/are preferably made of elastomer, preferably based on ethylene vinyl acetate or on polyurethane.
In a variant, the sole of the present disclosure includes one or more removable shock-absorber parts, and holder means arranged on the main shock-absorber part and/or the or said removable shock-absorber part(s), so as to enable the or said shock-absorber part(s) to be secured in removable manner in the medial and/or lateral cavity(ies).
The removable shock-absorber part(s) are made of elastomer, preferably based on ethylene vinyl acetate or on polyurethane.
The holder means may be grooves provided in the medial faces of the top and bottom elements defining the medial and lateral cavities, and slideways that are arranged on the main shock-absorber parts and that are suitable for co-operating with said grooves.
The holder means may also be fastener members of the male and female type, e.g. a plurality of lugs or projections provided on the medial faces of the top and bottom elements defining the medial and lateral cavities, and recesses arranged on the main shock-absorber part(s) that are suitable for co-operating with said lugs or projections.
Preferably, said holder means may be formed by overmolding the removable shock-absorber part(s) while molding the main shock-absorber part.
The shock-absorption of the sole may thus be matched to the user's stride type (universal, supinator, pronator) and weight.
Preferably, the medial and/or lateral cavities are visible and accessible from the outside of the shoe.
In a third aspect, the present disclosure provides a shoe, in particular for sporting activities, including a shoe sole in accordance with any one of the above-described variant embodiments.
The present disclosure can be better understood on reading a description of two embodiments of a shoe sole of the present disclosure, given by way of non-limiting example, and shown in the accompanying figures, in which:
The shoe sole 1 shown in
The main shock-absorber part 2 extends at least in the hindfoot region of the sole 1 from the medial side 9 towards the lateral side 8 of said sole 1.
The medial and lateral cavities 6, 7 open out respectively to the medial side 9 and to the lateral side 8 of the sole 1.
As can be seen in
Preferably, the partition element 5 has a curvilinear path (T′) in the hindfoot region 10 that is substantially symmetrical, about the middle axis (S) of the sole 1, to the path (T) of the center of pressure of the foot during spontaneous rolling of the foot on the ground, the rolling corresponding to a pronator- or universal-type stride in the specific embodiment shown in
The curvilinear path (T) of the pressure exerted on the foot while rolling on the ground is shown in
In this specific embodiment, the angle α1 formed by the axis (P) intersecting the middle axis (S) of the sole 1, and corresponding to a pronator- or universal-type stride, is less than or equal to 45°, preferably less than or equal to 20°.
In a variant, for a supinator-type stride for a left footprint, the angle α1 would lie in the range 20° to 45° and would also start from the medial side 106.
As can be seen in
The partition element 5, including its hind portion 5a that extends the hind edges 3a and 4a of the top and bottom elements 3, 4, follows the curvilinear path (T′) in the hindfoot region 10.
As can be seen in
Preferably, as can be seen in
The shoe sole 1, shown in
The lateral and medial cavities 7, 6 of the shoe sole 1, shown in
In operation, when the user's foot—having a pronator- or universal-type stride—strikes the ground in the lateral hindfoot region 107, because of the partition element 5, the sole 1 of the present disclosure accompanies and guides the foot towards its medial hindfoot region 106 so as to distribute the impact forces better over the entire hindfoot zone 10. Furthermore, the foot strikes the ground in its lateral hindfoot region 107, which, in operation, is arranged in register with the top and bottom lateral regions 13, 15 that are exempt from the hind portion 5a of the partition element 5, the regions 13 and 15 thus being more deformable.
Furthermore, since the partition element has an X-shaped structure in the hindfoot region 10, the lever arm between the partition element 5 and the lateral and medial regions 13, 14 of the top element 3 is considerable, thereby enabling said medial and lateral regions 14, 13 to deform significantly towards the bottom element 4.
Preferably, the sole 1 is molded from one or more thermoplastic polymers, in particular elastomers, selected from the following polymers: polyether block amide (such as those sold under the trade name PEBAX®); polyethylene copolymers; polyethylene terephthalate (such as those sold under the trade name HYTREL®); polyurethane.
Preferably, the sole 1 is molded from a mixture that mainly includes a polyether block amide having hardness on the Shore D scale that is greater than 50.
The sole 1 could be used without any cellular element.
In the ambit of the present disclosure, it is also possible to have medial and lateral shock-absorber parts 20, 21 that depend on the user's type of stride and weight.
As shown in
Finally,
| Number | Date | Country | Kind |
|---|---|---|---|
| 11 60640 | Nov 2011 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR2012/052684 | 11/22/2012 | WO | 00 | 5/14/2014 |
