FR2947994A3 - Inner sole for use in sole structure of trail running shoes, has profile adapted to foot of user, and material of rear area presenting value of rigidity, where value of rigidity of rear area is less than value of rigidity of front area - Google Patents

Abstract

The sole (1) has a profile adapted to a foot of user, where the sole is made of an elastomer or ethylene vinyl acetate. A material of a front area (1a) presents a value of rigidity, and a material of a rear area (1b) presents another value of rigidity, where the latter value of rigidity of the rear area is less than the former value of the rigidity of the front area. A raised rear edge (3) forms a cut for accommodating heel of the user, and a raised part (5) on level on an interior side supports an arch of the foot. A rising front part (7) provides a support for toes of the user. An independent claim is also included for a sole structure for shoes comprising an inner sole.

Description

The present invention relates to an insole for shoes, in particular an insole for hiking shoes.

The present invention also relates to a sole structure for shoes, particularly hiking shoes - which incorporates said insole.

BACKGROUND In the field of hiking shoes, the sole structure is of fundamental importance not only to guarantee high performance and maximum comfort, but also to avoid trauma to the foot of the user.

In particular, in hiking shoes it is necessary to ensure good shock absorption in the heel area, so as to dampen the impact with the ground. Such a feature is essential for the user's comfort in downhill runs, when the user's weight is transferred to the heel, and good damping is necessary to prevent stresses from the ground are transmitted to the heel of the user and from there spread along the leg, with the resulting damage to the bones, ligaments, tendons and muscles.

In addition, at the tip of the foot, high precision and sensitivity are required. This second characteristic is of fundamental importance in those parts of the route in which you have to climb on rocky slopes, because only a high sensitivity at the tip of the foot makes it possible to test and evaluate with certainty the holding of the points of view. support and correct positioning of the foot. The precision and sensitivity required require a rigid surface between the user's foot and the ground below the foot.

From what we have just explained above, it is evident that a sole structure with uniform and constant stiffness over its entire surface is not able to satisfy the requirements of a hiking boot described above. .

In order to obtain a differentially stiffened sole structure, it appears advantageous to combine with a homogeneous outer sole, provided with adequate adhesion and wear resistance characteristics, an insole which does not have a constant stiffness on all its surface.

The prior art has made known insoles or orthopedic footwear that have differentiated rigidities in the various areas of the foot of the user.

However, these insoles have a series of disadvantages. Firstly, the known insoles are not intended for hiking shoes and therefore their purpose is not to provide the sole structure of the shoe with the aforementioned characteristics.

Second, in principle the known insoles are obtained by introducing in a base body having a given rigidity one or more inserts in various materials of varied rigidity. By way of example, reference may be made to documents FR 2 511 851 and EP 488 727.

In a variant, the known insoles are even composed of two distinct elements made of different materials and rigidly connected to one another. By way of example, reference can be made to the document ES 1045 952 U.

The heterogeneous structure of known type insoles results in a complex and therefore expensive production process.

Furthermore, in the heterogeneous inner soles thus obtained, it is easy to see the presence of defects at the junctions between the parts of various materials used.

The object of the present invention is to overcome the drawbacks of the prior art, by providing an insole for footwear which is simple and economical to produce, comfortable for the user and which makes it possible to obtain differentiated rigidities in the various areas of the user's foot.

This and other objects are achieved by the shoe insole of the present invention as claimed in the claims as a whole.

Description of the Invention According to the present invention, the insole for shoes is homogeneous, it is made of a single material and it has a higher rigidity at the area of the tip of the foot and a lower rigidity at the level of the zone. heel.

Thanks to the homogeneous nature of the insole, the production process is simple and economical and produces an insole with no junction area that can deteriorate as a result of wear.

According to a preferred embodiment of the present invention, the insole is made of elastomer, in particular EVA (ethylene-vinyl acetate).

According to a preferred embodiment of the present invention, the insole has two areas of varied rigidity; however, depending on the particular requirements of specific applications, it is also possible to provide a greater number of areas with different rigidities from each other.

BRIEF DESCRIPTION OF THE DRAWINGS Additional advantages and features of the present invention will be evidenced by the following detailed description of a preferred embodiment of the insole according to the present invention, given by way of non-limiting example. and which refers to the accompanying drawings, in which: Figure 1A is a top view of the shoe insole according to the present invention; Figures 1B and 1C are side views of the inner shoe sole of Figure 1A; Figure 2 is a side view of a shoe sole structure incorporating the insole of Figures 1A-1C. Description of a Preferred Embodiment

We will illustrate an insole 1 for shoes according to the present invention with reference to Figures 1A-1C.

Said insole 1 has a profile adapted to adapt to the profile of the foot of the user and comprises in particular a raised rear edge 3 which forms a cut to accommodate the heel of the user, a raised part 5 at the level of the user's foot. interior side to support the arch and a rising front 7 to provide support for the user's toes.

According to the present invention, the insole 1 is made of a single homogeneous piece made of a single material.

In principle, according to the present invention the inner sole 1 is made of elastomer. According to a preferred embodiment of the present invention, the insole 1 is entirely made of EVA (ethylene-vinyl acetate). However, said insole could be made of any other material known to those skilled in the art for making footwear insoles.

Still according to the present invention, said insole comprises at least two regions which have different rigidities.

In particular, according to the present invention, said insole comprises at least a first region before the one in which said material has a first value of rigidity and a second rear region lb in which said material has a second value of rigidity, said second value of rigidity the rear region lb being less than said first stiffness value of the region before the.

In principle, according to the present invention, this difference in rigidity is obtained by using the same material, but with different densities in the region before and in the rear region 1b.

By way of nonlimiting example, the front region of the insole 1 could have a stiffness of about 80 Shore A, while the rear region lb of the insole 1 could have a rigidity of the order of 60 Shore A.

It is obvious that the insole 1 achieves the pre-established objectives because on the one hand it is performed as a single homogeneous body and on the other hand it allows to obtain a high sensitivity and accuracy in the area tip of the user's foot and at the same time good shock absorption at the level of the heel area.

It is also evident that the insole 1 could comprise any number of zones (not necessarily two), each with its own specific stiffness value. By way of example, the middle region of the insole 1 could be made with intermediate rigidity, the arch support area could be made with a specific rigidity and so on.

The insole 1 can be made using any suitable technique known to those skilled in the art.

For example, in the case where the insole 1 is made of EVA or another elastomer, it can be obtained in the following way: inside a single mold 15 for insoles for shoes of anatomically, a first amount of material is introduced at the front portion of the mold with a first preset density value and at the back of the mold a second amount of material with a second predetermined density value; thereafter the mold is brought to a temperature sufficiently high to cause the expansion of the material contained therein and the cohesion of said material to obtain the single and homogeneous body which constitutes the insole 1. 25 If we now move to 2, there is illustrated a sole structure for shoes, in particular for hiking shoes, which incorporates the insole 1 according to the present invention. In the sole structure shown, the insole 1 constitutes the upper component, or the innermost component, which, in use, is directly in contact with the user's foot. the insole 1 is associated with a rigid underfoot 11, of uniform thickness and stiffness, which has a profile which follows the profile of the lower surface of the insole 1.

For this purpose, the lower surface of the insole 1 may have a lower housing to accommodate the subfoot 11. The sub-foot 11 may be made of nylon, carbon fiber, fiberglass or the like.

Note that the assembly constituted by the insole 15 1 and the subfoot 11 allows to give shape and structure to the shoe and during the process of making the shoe is connected the upper of the shoe itself precisely to the rigid underfoot 11 and the insole 1 associated therewith. The sole structure is then completed by an outsole 21 which is located below the subfoot 11 and has adequate adhesion and wear resistance characteristics. Preferably, the outsole 21 is made, according to a known technique, vulcanized rubber or similar material and has at its lower part an over-thickness with a design designated by tank track.

According to a preferred embodiment, the sole structure further comprises a damping wedge 31 located between the rigid sub-foot 11 and the outer sole 21 at the level of the heel area.

The damping effect of the shim 31 is added to the damping effect of the rear portion 1b of the insole 1 of the present invention, and thus makes it possible to further improve the damping of the sole structure at the heel area of the user.

The damping wedge 31 will preferably be made of polyurethane, EVA or a similar material capable of absorbing shocks.

Note that the presence of the rigid foot 11 between the insole 1 and the wedge 31 advantageously allows to separate the damping effect of said insole (which will be solicited in particular by the weight of the user who is exercising from top to bottom) of that of said wedge 31 (which will provide a special damping of the stresses due to the unevenness of the ground below).

It is obvious that all that has been described and illustrated above was only an example and that many variations and modifications are possible without departing from the scope of the invention as defined by the set of claims.25

Claims (5)

REVENDICATIONS1. Insole (1) for shoes, of the type which has a profile adapted to adapt to the profile of the foot of the user, said insole being made in one piece made of a single material and comprising at least two regions which have rigidities different from one another, characterized in that it comprises at least a first front region (la) in which said material has a first value of rigidity and a second rear region (1b) in which said material has a second stiffness value, said second stiffness value of the rear region (1b) being less than said first stiffness value of the front region (1a). The insole (1) for shoes according to claim 1, wherein said insole is made of elastomer. The insole (1) for shoes according to claim 2, wherein said insole is made of EVA (ethylene-vinyl acetate). Footwear sole structure, characterized in that it comprises at least: an insole (1) according to any one of claims 1 to 3; a rigid underfoot (11) associated with the lower surface of said insole (1); an outsole (21) disposed beneath said rigid subfloor (11). 30 The shoe sole structure according to claim 4, further comprising a cushioning wedge (31) positioned between said rigid underfoot (11) and said outsole (21) at the rear portion of said structure of sole.