WO1991012740A1

WO1991012740A1 - Inner sole for footwear

Info

Publication number: WO1991012740A1
Application number: PCT/FR1991/000137
Authority: WO
Inventors: Loïc DAVID
Original assignee: Loic David
Priority date: 1990-02-20
Filing date: 1991-02-20
Publication date: 1991-09-05
Also published as: DE69102951T2; DE69102951D1; ATE108622T1; EP0469138A1; CA2050299C; JPH04503626A; FR2658397A1; FR2658397B1; EP0469138B1; JPH0698053B2

Abstract

The disclosed sole is made of a semi-rigid heat-shapable material and is obtained by moulding so as to present a profile corresponding to the general shape of the lower surface of a standard foot, of which the external edge (2b) is intended, in its central portion, to bear against the upper (5) of the shoe (6) substantially perpendicularly thereto, and of which the inner edge (2a), intended to bear against the internal wall of the central area (5a) of the upper (5) substantially tangentially thereto, is raised with respect to the low portion of the sole so that the area (2c) which it delimits forms a suspended zone rising progressively from the low portion of the sole, substantially from the median line thereof up to the raised inner edge (2a), the suspended zone (2c) of the sole being arranged so that, after setting the sole in the shoe, it adapts itself to the particular shape of the user's foot under the effect of the user's weight, by sliding along the upper of the sole region abutting tangentially there against.

Description

SHOE INSOLE

The present invention relates to an insole of chaus¬ sure.

The foot has, in its bone conformation more or less arcuate, ^• 5 a bottom surface that does not rely on the floor uniformly and the different parts are unevenly stretched.

The arch is suspended in the manner of a marquee and is supported by muscles, which gives it relative flexibility allowing it to absorb the different pressures applied by the weight of the body on the lower surface of the foot during standing, walking, running or carrying heavy loads, and to build up a shock absorber of this weight.

The heel, the metatarsal heads, and in particular the first and the fifth, as well as the big toe are the most stressed bearing surfaces.

To support the foot and distribute its support on the ground, there are currently many soles offering an anatomical profile, which can be grouped into two main types:

- On the one hand, those produced industrially, which have a profile 0 corresponding to the general shape of the lower surface of the foot and which may include flexible or cushioning materials for health over all or part of their surface and in particular at level of the parts of the foot subjected to significant supports or even to shocks. These soles have the disadvantage of not ensuring effective support for the foot since they are not adapted to the morphology of the arch of each user, which is very variable depending on the individual; this results in painful solicitation of the muscle supporting the arch of the foot, which can cause cramps;

- On the other hand, insoles molded to the shape 0 of the lower surface of the foot of the user and which espouse it perfectly. These soles provide good arch support, but cannot be produced industrially, and are reserved for specific jobs by people with the skills and equipment necessary to carry them out, such as podiatrists or orthopedists. 5 The object of the invention is to provide a sole which is produced industrially, and which nevertheless has capacities for immediate adaptation to the shape of the user's foot, without requiring the setting using complex means. Another object of the invention is to provide a sole adapted to the shape of the user's foot, that is to say providing precise anatomical support, but nevertheless elastic, to fulfill the physiological function of shock absorber and ensure good comfort.

To this end, the sole it relates to is made of a semi-rigid thermoformable material and is obtained by molding so as to have a profile corresponding to the general shape of the lower surface of a standard foot, the outer edge of which is intended, in its central part, to bear against the upper of the shoe substantially perpendicular thereto, and whose inner edge, intended to bear against the inner wall of the central area of the upper substantially tangential thereto , is raised relative to the lower part of the sole, so that the zone which it delimits forms a suspended zone rising regularly from the lower part of the sole, substantially from the center line thereof. up to the raised inner edge, the suspended area of the sole being arranged so that, after putting the sole in the shoe, it adapts to the particular shape of the foot of the u iliator under the action of the weight thereof, by sliding along the upper of the sole area in tangential support against the latter.

Thus, this sole, although produced industrially, can acquire the shape corresponding to the exact anatomy of the foot of the user, thanks to the blocking of the outer edge against the upper, and to the possibility of sliding of the inner edge taking tangential support against the rod, accompanied by a deformation of the suspended area depending on the shape of the user's foot.

The support of the arch of the foot is perfectly ensured, the sole providing, permanently, a bearing base to the entire foot, increasing the stability of the latter and avoiding the twists of the ankles implied by certain characteristic morphologies. In addition, the circulation of blood in the foot is stimulated by "pump effect", due to the suspended area which flexes elastically when the foot is pressed on the ground. According to a first embodiment of this sole, the suspended area is mechanically deformable.

For this purpose, the hanging area has slots, recesses or notches opening into the inner edge delimiting the suspen¬ due area.

The sole is thus self-adaptable to the foot while possessing the qualities of elasticity necessary for the movements of the feet during certain activities, in particular sports.

The shape, the orientation and the number of these notches, slots or recesses make it possible to adapt the elasticity of the sole and the progressiveness of its flexibility as a function of the desired support of the arch and the desired performance. According to another characteristic of the invention, the suspended area is made of a thermoformable material at a temperature below 100 ° C.

It is thus possible to heat the sole, using simple means, such as a hair dryer to soften the sole and make it malleable before introducing it into a shoe and shaping it by pressing a foot of the user, which allows adaptation to the morphological cases of extremely arched or flat feet, and for which the amplitude of mechanical deformation of the sole is not sufficient. Advantageously, the heel of the sole is delimited by a raised edge intended to take a tangential support against the upper, and delimiting a suspended area.

This suspended zone also ensures self-adaptation of the rear part of the sole to the shape of the user's heel, and stabilizes the heel laterally when it comes into contact with the ground.

According to a first possibility, the sole is produced by thermoforming, on a corresponding shape, of at least two layers of materials assembled together, at least one of which is semi-rigid, these layers being able to be formed, for example, by crosslinked polyethylene or non-crosslinked, a thermoformable elastomer, supports coated with polyisoprene or polycaprolactone derivatives. These materials have a certain rigidity allowing an effective hold and support for the foot. According to a second possibility, the sole is produced by injection, the materials used can be of polyvinyl chloride, polyurethane, or ABS (Acrylonitrile - Butadiene - Styrene) type. The shape, the orientation and the number of these notches, slots or recesses make it possible to adapt the elasticity of the sole and the progressiveness of its flexibility as a function of the desired support of the arch and the desired performance. Preferably, in the metatarsal zones, the layers of semi-rigid thermomouldable material comprise notches. Thus, in these very stressed areas, the flexibility of the sole is increased.

For perfect comfort, the sole includes cushioning parts and support parts arranged in the impact zones.

Advantageously, in the case where the sole is produced by thermoforming of several layers of material assembled together, the layers of semi-rigid material include cutouts covered by the outer layers. Thus, shock absorbing mattresses are produced, the cavities delimited by the cutouts possibly containing air, a fluid or a shock absorbing material.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, as non-limiting examples, several embodiments of an insole according to the invention.

Figure 1 is a perspective view; Figure 2 is a bottom view; Figure 3 is a side view;

Figure 4 is a sectional view along IV-IV of Figure 2; Figure 5 is a cross-sectional view of a shoe fitted with this sole;

Figures 6,7 and 8 are bottom views of three different embodiments of this sole;

Figure 9 is a sectional view along IX-IX of Figure 7. Figure 1 shows a sole 2 having a profile correspon¬ dant to the general shape of the lower surface of the foot and which is molded in a thermoformable material at low temperature , that is to say between 65 and 100 ° C.

The edge 2a located on the inner side of the foot is raised so that the zone 2c of the sole 2 which it delimits forms a suspended arch 3 substantially from the center line of the sole 2, this suspended zone tangentially connecting with the bottom of the shoe. The rear part of the sole 2 includes a raised edge 2d delimiting a bowl.

As shown in Figure 5, the edge 2b located on the outer side of the foot is intended to bear against the upper 5 of the shoe 6 substantially perpendicular thereto, while the edge 2a located on the inner side of the foot is intended to bear against the internal wall of the central zone 5a of the rod 5, substantially tangential to it. The edge 2d is also intended to bear substantially tangentially to the rod 5. The sole is stabilized by pressing its edges 2a and 2b against the rod 5. The foot is supported on it in order to make it acquire the shape corresponding to the exact anatomy of its lower surface. The arch 3 defines a void 10 between the sole 2 and the first 7 at the bottom of the shoe 6, allowing, when the arch of the foot is in abutment against the zone 2c of the sole 2, to make this zone 2c elastically deformable so as to what it can sink when the foot exerts pressure on it and resume its initial shape when this pressure is released. Thus, the self-adaptation of the sole 2 to the particular shape of this foot is achieved by sliding along the upper 5 under the action of the pressure thereof when the shoe 6 is closed, areas in tangential support.

Figures 2 to 'i show from different angles an improved embodiment of this sole in which the same elements are designated by the same references as above. The sole 20 which they represent is produced by thermoforming on a corresponding shape and assembly between them of two layers 21 and 22, the semi-rigid layer 21 being constituted by cross-linked polyethylene and the layer 22 by an elastic foam. comfort, such as polyurethane. The part 20c forming the arch 3 comprises slots 25 and notches 26 opening into the edge 20a of the sole 20, formed substantially transversely relative to the longitudinal axis of the latter, and making it possible to modulate its elasticity and the progressiveness of its flexibility. In addition, the sole 20 comprises zones 30 of lesser thickness constituted by cutouts made in the layer 21 and which make it possible to increase its flexibility at the level of the most stressed support surfaces of the foot, that is to say ie the big toe, the heads metatarsals and the heel.

Figures 6 to 8 show, seen from below, soles 201, 202 and 203 comprising a layer 221 of cross-linked polyethylene and a layer 222 of elastic comfort polyurethane foam. The layer 221 includes indentations 226 in the metatarsal areas, increasing its flexibility there.

The sole 201 further comprises a piece 223 of polyurethane foam interposed between the layers 221 and 222 increasing the damping of its front part, and a piece 22 of the heel support in shock absorbing foam, such as neoprene, polyurethane foam or expanded polyvinyl chloride.

In the sole 202, the layer 221 comprises a circular cut 230 at the heel, as can be seen in FIG. 9. The layer 222 and the part 224 cover this cut 230, which makes it possible to form an increasing air mattress the comfort and flexibility of the sole 202.

The sole 203 includes slots 225 increasing the flexibility of its raised part 203c.

Thanks to the conformation of the different layers or parts and to their positioning, the flexibility of the sole according to the invention can be adapted to different morphologies.

The invention is naturally not limited to the various embodiments described above by way of examples. On the contrary, it embraces all the variant embodiments and one would not depart from the framework of the invention by using other materials such as thermoformable elastomer, supports coated with de-poiyisoprene or derivatives polycaprolactone, or by making the sole by injection of polyvinyl chloride, polyurethane or ABS materials.

Claims

1.- shoe insole, characterized in that it is made of a semi-rigid thermoformable material and is obtained by molding so as to have a profile corresponding to the general shape of the lower surface of a standard foot, of which the outer edge (2b) is intended, in its central part, to rest ^* against the upper (5) of the shoe (6) substantially perpendicular to the latter, and whose inner edge (2a), intended to bear against the inner wall of the central zone (5a) of the rod (5) substantially tangential to it, is raised relative to the lower part of the "sole, so that the zone (2c ) that it delimits forms a suspended zone rising regularly from the lower part of the sole, substantially from the median line thereof to the raised inner edge (2a), the suspended zone (2c) of the sole being arranged so that, -5 after putting the a sole in the shoe, it adapts to the particular shape of the user's foot under the action of its weight, by sliding along the upper of the area of the sole in tangential support against this one.

2.- sole according to claim 1, characterized in that 0 the suspended area (2c) is mechanically deformable.

3.- sole according to claim 1, characterized in that the suspended area (2c) has slots (25, 225), recesses or notches (26) opening into the inner edge (2c, 20c) delimiting the suspended area. ._ Sole according to any one of claims 1 to 3, characterized in that the suspended zone (2c) is made of a thermoformable material at a temperature below 100 ° C, and is mechanically deformable after raising its temperature.

5.- Sole according to any one of claims 1 to, 0 characterized in that its heel is delimited by a raised edge (2d) intended to take a tangential support against the rod, and delimiting a suspended area.

6. Sole according to any one of claims 1 to 5, characterized in that it comprises at least two layers of material, 5 joined to one another, at least one of which is semi-rigid.

7. Sole according to claim 6, characterized in that, in the metatarsal areas, the layers (21, 221) made of thermo-material formable comprising notches (226), covered by the material of the outer layers (222, 224).

S.- Sole according to any one of claims 1 to 7, characterized in that the sole (2) is obtained by injection. 9. A sole according to any one of claims 1 to 7, characterized in that the sole (2) is obtained by thermoforming on a form.

10.- Sole according to any one of claims 1 to

9, characterized in that it comprises damping parts (223) and support parts (224) arranged in the impact zones. ^*