INSOLE

Description

[0001] The present invention relates to two-layer insoles in which the first layer has at least one recess which is filled by material of the second layer.

[0002] Insoles are separate inner soles that are placed in shoes for comfort or orthopedic reasons. The most common type of insole is the shoe insert, which is mass-produced industrially and offered in various shoe sizes. Insoles are frequently used for medical, especially orthopedic, reasons, but also in sports. Orthopedic insoles are often custom-made by an orthopedic shoemaker to fit the individual foot according to the medical indication, as they are intended to support the foot or correct misalignments.

[0003] Three-dimensionally shaped insoles are increasingly available, often featuring, for example, a raised metatarsal pad for transverse arch support, a support for the medial arch of the sole, and a depression for the heel cradle, frequently with additional pressure-absorbing pads or inserts under the heel bone. Insoles are also known where the surface consists of materials of varying hardness in different areas. Such insoles are disclosed, for example, in DE 20 2005 018 902 U1, DE 20 2005 019 691 U1, DE 10 2014 102 628 A1, DE 10 2009 060 933 A1, and DE 10 2012 021 696 A1.

[0004] DE 10 2018 129670 A1 reveals a multi-layered insole.

[0005] The production of such insoles from two materials often involves a complex injection molding technique in which the softer material is injected into molds of the harder material.

[0006] Furthermore, when manufacturing insoles with a surface made of two different materials, it is necessary to equalize the height of the materials by removing material from the surface.

[0007] The technical problem underlying the present invention is the provision of multi-layered insoles in which one layer partially overlaps another, forming a surface that is as continuous as possible between the two layers. The manufacture of these insoles should be as simple as possible, preferably eliminating the need for material removal to level the layers. In particular, the insole should be manufactured using a simple deep-drawing process.

[0008] Another technical challenge is providing an insole with zones of varying hardness, while ensuring a continuous and therefore comfortable footbed. In particular, the insole should be three-dimensionally deformable.

[0009] The present invention solves the underlying technical problem by means of the subject matter according to claim 1.

[0010] Surprisingly, it showed that insoles can be provided in which cutouts in the first layer, for example the layer facing the sole of the foot, can be easily filled by material from the second layer, for example the layer underneath, and still create a smooth, continuous surface.

[0011] The insole is manufactured using a thermoforming process. In this process, the cutouts for the first layer are created during the cutting process, for example, by die-cutting. The two layers are then bonded together with an adhesive film. In a subsequent thermoforming step, the insole is not only given its three-dimensional shape, but the cutouts in the first layer are also filled with material from the second layer, resulting in a surprisingly smooth surface. In particular, the boundary between the first and second layers is very even and barely perceptible, if at all, to the sole of the foot.

[0012] In a preferred embodiment, the first layer is at least partially bonded to the second layer by an adhesive film. In a preferred embodiment, the adhesive film is a polymer adhesive film. In a preferred embodiment, the adhesive film is a thermoplastic adhesive film. In a preferred embodiment, the adhesive film is a thermoplastic polymer adhesive film. Preferably, a film of the adhesive film is used.

[0013] Suitable adhesive films, in particular thermoplastic polymer adhesive films, are known to those skilled in the art. A thermoplastic adhesive film based on modified polyolefins is particularly preferred. The melting point of the adhesive film is preferably below 140 °C, and particularly preferably below 100 °C. The chemical base of the adhesive film is preferably EVA (ethylene-vinyl acetate copolymer), LDPE (low-density polyethylene), HDPE (high-density polyethylene), CoPA (polyamide block copolymer), TPU (thermoplastic polyurethane), or CoPES (copolyester). Preferably, the adhesive film contains at least one of these substances. Particularly preferably, the adhesive film contains EVA and / or LDPE and / or HDPE. The chemical base of the adhesive film is particularly preferred. The base of the adhesive film can also consist of mixtures of the aforementioned substances.

[0014] Preferably, the adhesive film has a thickness of no more than 0.5 mm. Preferably, the adhesive film is a foil that is applied to the first layer and / or the second layer during the manufacturing of the insole.

[0015] Surprisingly, it turned out that the first and second layers could be bonded with an adhesive film in such a way that they are not only permanently attached to each other, but can also be deep-drawn, and in particular, deep-drawn to such an extent that the material of the second layer penetrates and fills the recesses of the first layer. The existing adhesive film thus enables not only a permanent bond between the two layers, but also the production of the final product in a deep-drawing process in which the recesses of the first layer are filled by the second layer, and a three-dimensional shaping of both layers is simultaneously possible.

[0016] In a preferred embodiment, no adhesive film is present in the recesses.

[0017] This can be easily achieved by attaching the adhesive film to the first layer before insertion, for example, punching out the cutouts, so that the adhesive film is removed along with the cutouts, for example, when punched out.

[0018] In a preferred embodiment, the first layer and the material in the recess of the first layer form a closed, continuous surface.

[0019] A closed, continuous surface is understood to mean, in particular, a surface where none of the layers protrudes beyond the other layer. The surface can be flat or, in the case of a three-dimensionally shaped insole, curved.

[0020] In a preferred embodiment, it is not necessary to remove material from one or both layers to create the continuous surface. However, it is possible, and not excluded, to remove excess material by circular grinding. It is also possible that the surface has very narrow indentations at the interface between the material of the first layer and the material of the second layer. These indentations do not impair wearing comfort, however, as they are so small that they are not felt by the sole of the foot.

[0021] In a preferred embodiment, the insole is shaped three-dimensionally.

[0022] Suitable three-dimensional shapes for an insole are known to those skilled in the art. For example, arch supports can be provided. Preferably, the first and second layers are three-dimensionally shaped. Preferably, all layers are three-dimensionally shaped.

[0023] In a preferred embodiment, the first layer has several recesses which are filled by material of the second layer, in particular two recesses, three recesses, four recesses, five recesses or six recesses.

[0024] In a preferred embodiment, the first layer is the layer facing the foot.

[0025] Thus, the second layer is preferably located beneath the first layer and is therefore the layer facing the shoe sole. In this preferred embodiment, both the first layer and the material of the second layer, which fills the recesses of the first layer, face the foot. Therefore, when using the insole according to the invention, the foot preferably rests on a surface that consists partly of material from the first layer and partly of material from the second layer.

[0026] In a preferred embodiment, the material of the first layer has a different Shore hardness A than the material of the second layer.

[0027] Preferably, the material of the first layer is harder than the material of the second layer, particularly if the first layer is the layer facing the foot. In this preferred embodiment, the first layer forms the harder base layer on which the foot rests, with recesses in which the softer material of the second layer is located, thus creating a softer area of ​​the insole within the recessed section. Therefore, by positioning the recesses in the first layer, specific softer areas can be formed within the insole. Such areas are particularly suitable for relieving pressure on the foot at specific points and / or reducing pressure pain.

[0028] Alternatively, it is of course possible that the first layer is made of a softer material than the second layer, for example if specific harder stabilization points are to be formed.

[0029] Preferably, the material of the first layer has a Shore hardness of at least 40 Shore A. Preferably, the material of the second layer has a Shore hardness of at most 35 Shore A.

[0030] Preferably, the material of the first layer has a Shore hardness of at least 30 Shore A up to a maximum of 60 Shore A, preferably at least 35 Shore A and at most 55 Shore A, and particularly preferably at least 40 Shore A. Preferably, the material of the second layer has a Shore hardness of at least 15 Shore A. Preferably, the material of the second layer has a Shore hardness of at least 15 Shore A and at most 40 Shore A, preferably at least 20 Shore A and at most 33 Shore A, and particularly preferably at least 25 Shore A and at most 30 Shore A. Preferably, the material of the second layer has a Shore hardness of at most 30 Shore A.

[0031] The expert knows suitable Shore hardnesses for the layers and correspondingly usable materials.

[0032] In a preferred embodiment, the layer thickness of the first layer is less than the layer thickness of the second layer.

[0033] In a preferred embodiment, the thickness of the first layer is at least 0.5 mm. Preferably, the thickness of the first layer is at most 3.5 mm, more preferably at most 2 mm. Preferably, the thickness of the second layer, particularly in the area without recesses in the first layer, is at least 2 mm, more preferably at least 3 mm. The thickness of the second layer is more preferably at most 6 mm, more preferably at most 5 mm.

[0034] In a preferred embodiment, the material of the first layer and / or the material of the second layer is a thermoplastic.

[0035] Preferably, the material of the first layer and / or the material of the second layer is a cross-linked polyolefin foam.

[0036] Preferably, the material of the first layer and the material of the second layer are suitable for deep drawing. Such materials are known to those skilled in the art. Particularly preferably, the material of the first layer and / or the material of the second layer is a polyethylene foam or a foam containing polyethylene.

[0037] In a preferred embodiment, the insole has a third layer made of a third material.

[0038] In a preferred embodiment, the insole has a fourth layer made of a fourth material.

[0039] In addition to the first layer according to the invention, which has the recesses, and the second layer located on the first layer, the material of which fills the recesses of the first layer, a person skilled in the art can provide further layers that also form the insole. For example, a third layer can be provided on the side of the second layer facing away from the first layer, preferably a layer made of a material with a higher Shore hardness, and particularly preferably a layer for stiffening and stabilizing. This layer can preferably be used to stabilize the midfoot and / or hindfoot and thus to support corrective measures for foot deformities. Preferably, the third layer consists of a moistened textile fabric.

[0040] In a further embodiment, a fourth layer can be provided, preferably consisting of a cross-linked polyolefin foam, wherein the material of the fourth layer particularly preferably has a Shore hardness higher than that of the material of the first layer and / or the material of the second layer. The third layer is particularly preferably located between the second and fourth layers. In an alternative embodiment, the third layer can also be omitted.

[0041] In a preferred embodiment, the material of the third layer and / or the material of the fourth layer has a higher Shore hardness A than the material of the first layer and / or the material of the second layer. In a preferred embodiment, the material of the third layer has a higher Shore hardness A than the material of the first layer and the material of the second layer.

[0042] In a preferred embodiment, the materials of the individual layers, in particular the material of the first layer and the material of the second layer, have different colors. The different colors make the material boundaries easily visible. With different colors of the material of the first layer and the material of the second layer, the zones formed by the recesses in the first layer, especially the softer zones, are advantageously clearly visible.

[0043] Of course, the materials of the individual layers can also be the same color. If visual differentiation of the layers is desired, one or more layers can be made of a perforated material. The perforation of the layers can also be designed differently. Preferably, the second layer is made of a perforated material, but particularly preferably not the first layer.

[0044] In a preferred embodiment, the insole is an orthopedic shoe insert or a sports insole.

[0045] Further preferred embodiments are described in the dependent claims and the example.

[0046] The figures and the following example illustrate a preferred embodiment of the insole according to the invention, without the features shown being to be understood as limiting. Figure 1 shows an insole according to the invention. Figure 2 shows the layer structure of a preferred embodiment of an insole according to the invention.

[0047] Figure 1Figure 1 shows an insole 100 according to the invention in an oblique view. Visible is the upper first layer 10, which faces the foot and is made of a harder foam; the second layer 20, which is made of a softer foam; and the fourth layer 40, which, when used, faces the sole of the shoe and is made of a foam that is harder than the foam of the first layer. Between the second layer 20 and the fourth layer 40 lies a very thin and therefore barely visible third layer 30 made of a moistened textile fabric. The insole 100 has a typical three-dimensional shape, which was produced by a thermoforming process.

[0048] The upper, first layer 10 has four recesses 11. These recesses 11 are filled by material 21 of the second layer 20. Thus, when using the insole 100, a first surface 101 is formed for the foot, which is advantageously continuous even though it is formed from two different materials: the material of the first layer 10, which comprises material 21 of the second layer 20. For the user of the insole, the boundary between the two materials is nevertheless barely perceptible or not at all. The recesses 11 in the first layer 10 advantageously create zones that are softer than the other areas of the insole 100 due to the filling material 21 of the second layer 20, so that pressure on the foot is relieved in these zones and / or pressure pain is avoided.

[0049] Figure 2This shows the layer structure of the insole 100 in the edge area, i.e., in an area without cutouts in the first layer 10. Accordingly, the first layer 10, the second layer 20 below it, the third layer 30 below it, and the bottom layer 40 are visible. The thickness of the first layer 10 is approximately 1 mm, the thickness of the second layer 20 approximately 4 mm, the thickness of the third layer 30 less than 1 mm, and the thickness of the fourth layer 40 approximately 4 mm.

[0050] Not visible and therefore only indicated is an adhesive film 50, which connects the respective layers together, since the corresponding adhesive film is very thin at 0.1 mm and melts due to heat treatment during bonding.

Claims

1. An insole (100), having at least a first layer (10) of a first material and a second layer (20) of a second material, wherein the first layer (10) has at least one recess (11) which is filled out by material (21) of the second layer (20), wherein the first layer (10) is connected to the second layer (20) via an adhesive film (50) at least partially, wherein the insole is produced by a deep-drawing method, wherein the at least one recess (11) of the first layer (10) is introduced during cutting and thereafter the two layers (10, 20) are fastened to one another via the adhesive film (50) and a subsequent deep-drawing step takes place.

2. The insole (100) of claim 1, characterised in that no adhesive film (50) is present in the at least one recess (11).

3. The insole (100) of one of the preceding claims, characterised in that the first layer (10) and the material (21) of the second layer (20) in the at least one recess (11) of the first layer (10) form a closed, continuous face (101).

4. The insole (100) of one of the preceding claims, characterised in that the insole (100) is three-dimensionally shaped.

5. The insole (100) of one of the preceding claims, characterised in that the first layer (10) is the layer facing the foot.

6. The insole (100) of one of the preceding claims, characterised in that the material of the first layer (10) has a different Shore hardness A than the material of the second layer (20).

7. The insole (100) of one of the preceding claims, characterised in that the layer thickness of the first layer (10) is less than the layer thickness of the second layer (20).

8. The insole (100) of one of the preceding claims, characterised in that the material of the first layer (10) and / or the material of the second layer (20) is a thermoplastic.

9. The insole (100) of one of the preceding claims, characterised in that the adhesive film (50) is a thermoplastic polymer adhesive film.

10. The insole (100) of one of the preceding claims, characterised in that the insole (100) has a third layer (30) of a third material.

11. The insole (100) of one of the preceding claims, characterised in that the insole (100) has a fourth layer (40) of a fourth material.

12. The insole (100) according to one of claims 10 or 11, characterised in that the material of the third layer (30) and / or the material of the fourth layer (40) has a higher Shore hardness A than the material of the first layer (10) and / or the material of the second layer (20).

13. The insole (100) of one of the preceding claims, characterised in that the insole (100) is an orthopaedic shoe insole or a sports insole.

14. The insole (100) of one of the preceding claims, characterised in that, during the deep-drawing step, the material of the second layer (20) penetrates into the at least one recess (11) of the first layer (10) and fills it out.