FR2769801A1 - Boot or shoe sole - Google Patents

Abstract

The sole is made from upper and lower layers (2, 3) with a series of blocks (4, 5, 6, 7, 8) of a synthetic material between them to ease the pressure on various parts of the foot or hold them above the ground until a certain force is applied. The blocks are situated round the outside or along the areas of the foot which are subjected to the greatest pressure the heel, metatarsal zones and big toe. They can be made in one piece with the upper and lower layers by moulding or machining. The upper layer is some 3 mm thick, with density lower than that of the blocks, which are 2 - 4 mm thick, and the blocks are of the same or lower density than the 2 mm thick lower layer.

Description

 The present invention relates to a shoe sole.

This sole can constitute a so-called cleanliness sole, having the general shape of the foot, and which can improve the comfort of the user due to a certain flexibility, or constitute the outer sole of a shoe.

 Some insoles can be fitted with comfort or cushioning elements made up of pads made of suitable materials, attached under the heel and under the pad of the foot. These soles do not have characteristics specific to the movement and the deformation of the structure of the foot in dynamics.

 Other insoles, of the orthopedic type, incorporate so-called corrective, stimulatory or proprioceptive elements having the effect of correcting a deformation of the foot by using wedges appearing in relief on the face of the sole against which the user's foot takes support. To be effective, these shims must be relatively rigid. These wedges must be placed in specific locations and / or locations corresponding to nerve or stimulating sensors. The places are located by orthopedists or podiatrists according to a medical prescription. These are corrective soles intended to modify a malformation or deformation of the foot, which are uncomfortable, even traumatic.

 In all cases, the known soles fill the gap between the bottom of the shoe and the foot.

 These different types of soles can exist in thermoformable version, insofar as they incorporate at least one sheet of resin or polyolefin. Such soles are hot molded to the particular anatomy of the foot by a podiatrist or a technician.

 The object of the invention is to provide a shoe sole which is comfortable, and allows stabilization of the foot in the shoe, and to limit the collapse of certain areas of the foot while respecting the elastic deformation thereof. up to a certain limit, where this deformation becomes exaggerated and may be traumatic.

 To this end, the sole which it concerns, curved in the general shape of a foot, has, under its underside, protruding parts forming shims, arranged at the foot support areas and / or in periphery of the support zones, and of the empty spaces forming arches, arranged between the projecting parts, some of the wedges serving for permanent support of the sole, while other wedges are suspended when the sole is at rest, and become active by forming supports only when a predetermined minimum load is exerted on the sole.

 The empty spaces form flexible arches, acting as spring blades and making it possible to cushion the deformation of the foot. Under the effect of pressure, the wedges, which have different heights, can compress or come to bear on the bottom of the shoe, to ensure, depending on their nature, the stabilization of the foot if they are relatively rigid, or the shock absorption if they are made of an absorbent material, storing energy which will be restored when the pressure decreases, promoting walking, running, and saving muscle energy.

 This sole provides increased comfort, a good distribution of support with discharge from the areas where the support is most important, stabilization and control of the deformation of the foot, energy return, as well as a massage of the arch of the foot. and blood stimulation.

 Advantageously, this sole includes stabilizing shims arranged on the periphery or along the support zones of the foot at the level of which maximum pressure is exerted and comprises, in the support zones of the foot at the level of which pressure is exerted maximum, or in sensitive areas, shocks that are damping and / or capable of restoring energy.

 The stabilization wedges are arranged on the periphery of the heel and / or in front of and / or behind the area used to support the metatarsal heads and the damping or energy restoring wedges are arranged in the heel, and / or areas used to support the metatarsal heads and / or the big toe.

 This sole provides stabilization and comfortable support for the architecture of the foot, insofar as the stabilization wedges are not arranged at the actual support zones, but around these support zones. This stabilization is accompanied by a discharge of the support zones, which is improved by the presence of elastic bridging between the wedges. Finally, the shock absorbing or energy return wedges improve cushioning and comfort without being excessively stressed under normal shoe use conditions. Indeed, these wedges only become active when the pressure is sufficient to bring them into contact with the bottom of the shoe. This has an advantage because these materials are often fragile, and quickly settle and lose their effectiveness when subjected to constant pressure. In addition, these materials, given their flexibility, reduce the proprioceptive sensitivity when used excessively, and annihilate the skin sensations of the foot.

 This sole has an elastic effect promoting walking and sports practice by energy return, as well as blood circulation by massaging the plantar fascia, with each step.

 According to a simple embodiment, this sole is constituted by a block or a sheet of synthetic material molded or shaped by machining.

 According to another embodiment, this sole, of the type comprising an upper sheet on which a user's foot is intended to bear, a lower sheet, and an intermediate layer, which are assembled, is characterized in that the intermediate layer comprises elements arranged in a localized manner and not occupying the entire surface of the sole, leaving empty spaces between them, the lower sheet being deformed to match the profile of the empty spaces formed between the elements of the intermediate layer, and be pressed and fixed, at these spaces, directly against the top sheet to provide hanging parts or arches.

 The sole according to the invention may be suitable for mass production, and possibly include one or more thermoformable materials in order to be molded precisely to the shape of the foot of each individual.

 For this purpose, if the lower and upper sheets do not have thermoformable characteristics, the intermediate layer may include a sheet of thermoformable resin on all or part of the surface of the sole.

 According to one embodiment of this sole, the upper sheet, the wedge elements and the lower sheet are made of foams of synthetic materials, such as polyethylene, polyurethane, or ethylene vinyl acetate, the density of the upper sheet being lower. to that of the wedge-forming elements of the intermediate layer, which is itself less than or equal to that of the lower sheet.

 The top sheet is an element of comfort that can be covered with natural or synthetic skin.

 The lower sheet must be flexible enough to deform and conform to the empty spaces between the elements of the intermediate layer, but also have good longitudinal strength and offer sufficient resistance to wear with respect to the friction at the bottom of the shoe.

 According to one possibility, the thickness of the upper sheet is less than or equal to about 3 mm, the thickness of the elements forming shims is of the order of 2 to 4 mm and the thickness of the lower sheet is less than or equal to about 2 mm.

In accordance with another characteristic of the invention,
The thickness of the shock absorbing or energy restitution elements, belonging to the intermediate layer, is less than or equal to the thickness of the elements forming shims, and less than or equal to approximately 2.5 mm.

 It should be noted that the thickness of the damping elements is less than or equal to that of the wedges, so that they do not return to function until the sole has been sufficiently deformed under the action of a stress.

 In the case where the sole is intended to form an outer sole of the shoe, the lower sheet is made of a wear-resistant material.

 According to another characteristic of the invention, shims protruding from the underside of the sole are arranged opposite areas of the foot comprising reflectological sensors, the upper face of the sole having slight bumps facing these wedges.

Anyway, the invention will be clearly understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of nonlimiting examples, two embodiments of this sole.
Figure 1 is an exploded perspective view of the components of a first sole
Figure 2 is a very schematic top view of this first sole illustrating the position of the various components
Figures 3 and 4 are two views in respectively longitudinal and transverse section of this sole on lines 111-111 and IV-IV of Figure 2;
Figure 5 is a top view of a second sole, similar to the representation of Figure 2
Figure 6 is a longitudinal sectional view of this second sole according to line VI-VI of Figure 5
Figure 7 is a very schematic view showing the different support areas of a foot
Figures 8 and 9 show an embodiment of the sole of Figure 3.

 Figure 1 shows a first sole in exploded view.

This sole includes an upper sheet 2, intended to serve as a support for the user's foot. This sheet 2 has a shape close to the shape of the foot of the user and provides a softness necessary for comfort. This sheet is produced for example using foam of synthetic material, such as polyethylene, polyurethane, or ethylene vinyl acetate. Insofar as the upper sheet 2 is made of ethylene vinyl acetate, it has a density of the order of 70 kg / m3 and a shore hardness of between 30 and 50. This sheet can be covered with natural or synthetic skin , and its thickness is less than about 3 mm.

 This sole also includes a lower sheet 3 which is intended to bear on the bottom of the shoe. This lower sheet must have good longitudinal resistance and resist wear due to friction against the bottom of the shoe. It must also be able to be deformed for the reasons which will be indicated below. It can be made of polyethylene with a density of 150 to 250 kg / m3 and a thickness less than or equal to 2 mm.

 Between the upper sheet 2 and the lower sheet 3 is disposed an intermediate layer formed by different elements. The intermediate layer firstly comprises elements forming shims, in this case a shim 4 surrounding the heel, and a shim 5 disposed behind the metatarsal heads.

 These shims 4 and 5 are made of materials, such as polyethylene, ethylene vinyl acetate or polyurethane foam, with a density greater than the density of the material of the upper sheet, for example polyethylene with a density of 90 to 160 kg / m3.

The thickness of these shims is between 2 and 4 mm.

 The intermediate layer finally includes elements in the sensitive areas of the foot, and on which maximum pressure is exerted. It is in particular an element 6 disposed at the heel, an element 7 disposed at the metatarsal heads and an element 8 disposed at the big toe. These elements can be made of a material capable of absorbing shocks, improving comfort, and promoting propulsion by an energy restoring effect. The thickness of such elements 6, 7, 8 is less than that of the shims 5, and does not exceed 2.5 mm.

 Between the elements 4, 5, 6, 7 and 8, empty spaces 9 are formed.

 The sole is produced from the various components defined above, by molding, either industrially by thermocompression or under vacuum, by being pressed onto a standard shape by a rubber membrane, or by compression on the foot of the user. In industrial thermocompression techniques using rigid molds, the female or lower parts of these molds incorporate extra thicknesses corresponding to the areas of the sole having empty spaces, so that after molding, and as shown in FIGS. 3 and 4, the lower sheet 3 comes to the level of these empty spaces to press against and be fixed against the upper sheet 2, forming hanging zones 10 which do not rest on the bottom of the shoe. These hanging areas provide elastic support to the foot and flex under increasing pressure. The zones comprising wedges 4, 5 resting at the bottom of the shoe and not offering an elastic vacuum create an overpressure on the upper face of the sole, therefore on the foot, when the latter withstands pressure. This results in a progressive stabilization of the foot with control of the deformation of the structure thereof. As regards the elements 6, 7, they become active, given their thickness, when the pressure is sufficient to bring them into contact with the bottom of the shoe.

 The effect provided by this sole is perfectly apparent from the illustration in FIG. 7 which diagrams the areas of support of a foot on the ground. The surfaces with cross hatching correspond to the bearing surfaces with high pressure. These are the heel 12 and the first and fifth metatarsal heads 13, 14. The areas comprising a single hatch correspond to a surface 15 of partial contact of the foot when resting on the ground. The unshaded areas 16 correspond to the suspended areas, such as the arch of the foot. The sole according to the invention therefore makes it possible to provide support around the heel 12, behind the metatarsal heads 13, 14, and to ensure comfortable support of these areas 12, 13, 14 thanks to the presence of elements 6 , 7 absorbing energy, an element 8 of the same nature which can also be placed under the big toe which is particularly stressed during the practice of certain sports, such as running or skiing.

 Figures 5 and 6 show an alternative embodiment of this sole in the case of sports in which significant support is exerted on the inside of the foot. It can be for example the practice of golf but also skiing or skating.

 In this case, the intermediate layer comprises a shim 24, the length of the inner side of which is greater than the length of the outer side, and which is made of a material with several densities, the density of the inner side being greater than the density of the exterior side. It would also be possible to envisage a greater thickness on the inner side than on the outer side of the sole. This sole also includes two wedges 25 and 26 respectively disposed behind and in front of the metatarsal areas. These shims 25 and 26 also have a higher density on the side of the inside of the sole than that on the side of the outside of the sole.

 The intermediate layer finally comprises elements 27, 28 and 29 made of shock absorbing material. The element 27 is disposed between the wedges 24 and 25. This element 27 has a thickness and a density greater in the area of the heel 12 than those which are found further forward. The element 28 has, for its part, a higher density on the side of the interior of the sole than that on the exterior side of the sole.

The element 29 located under the big toe has the same thickness and the same density as the element 28 in its part located on the side of the interior of the sole.

 The structure of the thicker and / or denser shims 24, 25, 26 on the external side makes it possible to more effectively support the architecture of the foot and to avoid its collapse when the pressure on the internal side of the foot is maximum. Similarly, the elements 27, 28, 29, given their locally variable densities and thicknesses, make it possible to improve the damping or elastic yield. Finally, the shims 24, 25, 26 being thicker and denser than the elements 27, 28, 29 make it possible to obtain an elastic bridging effect at the level of the suspended zones 30.

 Figures 8 and 9 illustrate an embodiment of the sole shown in Figures 1 to 4, in the case of its application to the production of an outer sole of a shoe. In this new embodiment, the same elements are designated by the same references as above. It appears from these two views that certain wedges are used for permanent support, while other wedges, such as wedge 5, are suspended when the sole is at rest (FIG. 8) and become active by forming supports only when '' a minimal load is exerted on the sole (figure 9).

 The upper sheet 2 constitutes the bottom of the shoe, and the lower sheet 3 must be made of a wear-resistant material. Figure 8 shows the sole when no load is exerted on the ground, while Figure 9 shows the sole under load.

 As is clear from the foregoing, the invention brings a great improvement to the existing technique by providing an inner sole of the shoe providing great comfort to the user, while ensuring good grip of the foot in the shoe, avoiding the collapse of the architecture of the foot under the effect of a pressure exerted by it in the shoe, and ensuring a damping and energy restoring effect, insofar as the sole equips a sports shoe .

 As it goes without saying, the invention is not limited to the sole embodiments of this sole, described above by way of examples, on the contrary it embraces all variants.

 Thus, in particular, the sole could consist of a block or a sheet of synthetic material molded or shaped by machining, without thereby departing from the scope of the invention.

Claims (14)

 1. Shoe sole curved in the general shape of a foot, characterized in that it has, under its underside, projecting parts forming wedges (4, 5, 6, 7, 8, 24, 25, 26, 27, 28, 29), arranged at the support zones of the foot and / or at the periphery of the support zones, and empty spaces forming arches, arranged between the protruding parts, some of the wedges serving to permanent support of the sole, while other wedges are suspended when the sole is at rest, and become active by forming supports only when a predetermined minimum load is exerted on the sole.  2. Sole according to claim 1, characterized in that it comprises shims (4, 5, 24, 25, 26) disposed on the periphery or along the support zones of the foot at which maximum pressure is exerted. .  3. Sole according to claim 2, characterized in that the wedges (4, 5, 24, 25, 26) are arranged on the periphery of the heel and / or in front and / or behind the area used for support. metatarsal heads.  4. Sole according to any one of claims 1 to 3, characterized in that it comprises, in the support areas of the foot at which maximum pressure is exerted, or in sensitive areas, wedges (6 , 7, 27, 28, 29) shock absorbers and / or capable of energy restitution.  5. Sole according to claim 4, characterized in that the shims (6, 7, 27, 28, 29) shock absorbers and / or energy return are arranged at the heel, and / or areas used for support of the metatarsal heads and / or the big toe.  6. Sole according to any one of claims 1 to 5, characterized in that it is constituted by a block or a sheet of synthetic material molded or shaped by machining.  7. Sole according to any one of claims 1 to 5, of the type comprising an upper sheet (2) on which a foot of the user is intended to bear, a lower sheet (3), and an intermediate layer, which are assembled, characterized in that the intermediate layer has wedge elements (4, 5, 6, 7, 8, 24, 25, 26, 27, 28, 29) arranged in a localized manner and not occupying the entire surface of the sole, by leaving empty spaces (9) between them, the lower sheet (3) being deformed to match the profile of the empty spaces (9) formed between the elements of the intermediate layer, and being pressed and fixed, at the level of these spaces, directly against the upper sheet (2) to provide suspended parts or arches.  8. Sole according to claim 7, characterized in that the intermediate layer comprises a sheet of thermoformable resin.  9. Sole according to claims 7 and 8, characterized in that the upper sheet (2), the elements (4, 5, 24, 25, 26) forming shims, and the lower sheet (3) are produced in foams of synthetic materials, such as polyethylene, polyurethane, or ethylene vinyl acetate, the density of the upper sheet (2) being lower than that of the elements (4, 5, 24, 25, 26) forming wedges of the intermediate layer, which is itself less than or equal to that of the bottom sheet (3).  10. Sole according to claims 7 to 9, characterized in that the thickness of the upper sheet (2) is less than or equal to about 3 mm, the thickness of the elements (4, 5, 24, 25, 26) forming shims is of the order of 2 to 4 mm and the thickness of the bottom sheet (3) is less than or equal to about 2 mm.  11. Sole according to claim 10, characterized in that the thickness of the elements (6, 7, 27, 28, 29) shock absorbers or energy restitution, belonging to the intermediate layer is less than or equal to the thickness of the elements (4, 5, 24, 25, 26) forming shims, and less than or equal to about 2.5 mm.  12. Sole according to any one of claims 7 to 11, characterized in that in the case where it is intended to form an outer sole of the shoe, the lower sheet (3) is made of a wear-resistant material.  13. Sole according to any one of claims 1 to 12, characterized in that wedges protruding from the underside of the sole are arranged opposite areas of the foot comprising reflectological sensors, the upper face of the sole having slight bumps opposite these wedges.  14. Sole according to any one of claims 1 to 13, characterized in that it has shims (4, 5, 6, 7, 8, 24, 25, 26, 27, 28, 29) projecting from its underside, with different heights.