Orthopedic shoe insole and method for producing same

Abstract

The invention relates to an orthopedic shoe insole having a main body which is arranged on the underside of the shoe insole and is produced from a composite material by injection molding. The orthopedic shoe insole has a covering which is located on the upper side of the main body in order to increase the wearing comfort of the shoe insole and is integrally molded onto the main body as a result of the injection molding of the main body. A first base material of the composite material is a thermoplastic material and a second base material matches a material of the covering.

Description

[0001] [File: 103021350.docx / / SP85K53] Description

[0002] Description

[0003] Orthopedic shoe insole and methods for manufacturing the same

[0004] The present invention relates to an orthopedic shoe insole comprising a base or support body made of a composite material and a covering on the upper surface of the base body. The present invention further relates to a method for manufacturing such a shoe insole.

[0005] For example, a shoe insole with a support body manufactured using the RIM process from a polyurethane foam and a cushioning body is known from the prior art. Since the cushioning or covering materials used in the prior art do not bond well with polyurethane foam, a carrier or bonding agent layer is also necessary to make the cushioning material bondable to the polyurethane foam material of the support body.

[0006] However, such an adhesive layer must be applied in a separate manufacturing step and, depending on its design, can also affect the cushioning properties of the shoe insole. For example, a textile backing layer used as an adhesive layer is disadvantageous in sole areas where good cushioning is desired, because the inherent property of textiles to be tensilely stiff in the longitudinal direction of the threads, i.e., in the plane of the textile, reduces cushioning, at least in this direction. On the other hand, elastic adhesive layers can impair a firm bond between the top layer / cover materials and the support structure in areas such as the longitudinal arch, as they reduce stiffness in this area. Therefore, the combination of a support structure with applied cushioning or top layer materials containing adhesive layers usually represents a less than ideal compromise.

[0007] In the prior art, such an adhesion promoter layer is also necessary in the RIM process because relatively low pressures and temperatures prevail in the tool during the RIM process, which do not allow a satisfactory direct material and / or form-fitting connection between the support body formed thereby and the ceiling material.

[0008] It is therefore an object of the present invention to provide an orthopedic shoe insole and a corresponding manufacturing method which provides a simple, cost-effective and reliable connection between a base or support body and a [File: 103021350.docx / / SP85K53] description

[0009] Covering the shoe insole allows for adjustment without negatively affecting the cushioning properties of the shoe insole.

[0010] The foregoing problem is solved by an orthopedic shoe insole according to claim 1 and the corresponding method for manufacturing such an orthopedic shoe insole according to claim 9. Preferred embodiments of the invention are the subject of the following dependent claims.

[0011] The orthopedic shoe insert according to the invention has a base or support body arranged on the underside of the shoe insert, which is manufactured from a composite material by injection molding. The base body serves to support the foot of a wearer of the shoe insert and can optionally be used to correct foot deformities. To increase the wearing comfort of the shoe insert, a cover or blanket is also arranged on the upper side of the base body, which is molded onto the base body by injection molding. According to the invention, a first base material of the composite material of the base body is a thermoplastic polymer, and a second base material of the composite material corresponds to a material of the cover.

[0012] By providing, according to the invention, a base body produced by injection molding, onto which the cover is molded by injection molding, the base body and cover can be reliably joined together in a simple manner without the use of a separate adhesion promoter layer. This is due, firstly, to the higher temperatures and pressures within the injection mold compared to the RIM process frequently used in the prior art, which lead to an improved material and / or form bond between the injection-molded base body and the cover. Thus, the injection molding material can be introduced under high pressure into existing irregularities in the surface of the cover facing the base body being formed, thereby creating a positive-locking connection between the cured base body and the cover.Furthermore, a binder present in the cover can be dissolved by the high temperatures during injection molding, thus improving the material bond between the base body and the cover.

[0013] Since, according to the invention, one of the base materials of the composite material for the base body is identical to the material of the cover, production waste and / or production rejects generated during the manufacture of the cover and / or the shoe insole according to the invention can be advantageously reused. Furthermore, depending on the type and quantity of the composite base material used, certain properties of the base body, such as its cushioning behavior or breathability, can be adjusted. [File: 103021350.docx / / SP85K53] Description

[0014] For example, a relatively coarsely ground cover material, which is used as a base material of the composite material, can improve the damping behavior and the moisture-regulating properties of the base body.

[0015] Furthermore, porous or fibrous structures of materials, which are provided on both the cover side and the base body side in the form of the second base material of the composite material, can improve the adhesion between the injection-molded base body and the cover in conjunction with the thermoplastic polymer as the first base material of the composite material.

[0016] The thermoplastic polymer that forms the first base material of the composite material can be, for example, TPU (thermoplastic polyurethane), EVA, polyethylene, polypropylene, or a mixture thereof. By selectively choosing such a first base material, desired properties of the injection molding material and the injection-molded base body of the shoe insole, such as desired degrees of hardness or cushioning properties, can be achieved. For example, the use of polypropylene, compared to polyethylene, results in a stiffer base body due to its higher density. The inherent properties of the aforementioned materials are known to those skilled in the art, so further explanation is unnecessary here.In addition to the materials mentioned above as examples in connection with the thermoplastic material, other materials can also be used, provided they are suitable for the described application.

[0017] Depending on the desired comfort and / or appearance of the shoe insole, materials such as cork, rubber, leather, synthetic leather, latex, or a foamed plastic can be used for the cover, or a textile cover can be provided. A cork cover offers excellent moisture-regulating properties, and the cushioning properties of the cover can be further adjusted by selecting the specific grain size of the cork granules used. Furthermore, using a foamed plastic as the cover material allows for a lightweight cover with very good cushioning properties, which can be further customized by varying the material thickness.Depending on the material used and its thickness, the cover according to the invention can also be designed as a cushioning element that conforms to the sole of the foot of the wearer of the shoe insole and dampens foot movements on the shoe insole. In addition to the materials mentioned above as examples in connection with the cover, other materials can also be used. [File: 103021350.docx / / SP85K53] Description.

[0018] They may be used provided they are suitable for the described application and can withstand shredding and the temperatures during the melting of the composite material.

[0019] The base body of the shoe insole according to the invention serves to provide anatomically and orthopedically effective support and guidance to the foot of the wearer of the shoe insole. For this purpose, the base body can support the entire shoe insole or only one or more sections of the shoe insole and thus be designed only in orthopedically effective support areas. For example, a base body can be provided with a recess in the heel area to cushion and softly support the calcaneus in this area, for example, by means of a foamed covering or lining material in the vertical direction.

[0020] Similarly, the cover can span the entire base body or only parts of it, and thus only be formed in areas where, for example, additional padding of the sole of the foot is required.

[0021] The shoe insole according to the invention can further be provided with an additional cover, which is applied, at least in certain areas, to the upper or lower surface of the injection-molded shoe insole according to the invention – with the cover being molded onto the base body according to the invention by injection molding. By providing an additional cover on the upper or lower surface of the shoe insole according to the invention, advantageous material properties of certain materials can be combined for the covers of the shoe insole in these areas. Furthermore, the additional cover can fix orthopedically effective accessories, such as pads, metatarsal pads, wedges, or the like, onto the shoe insole so that these are located in orthopedically predetermined support areas.

[0022] The shoe insole according to the invention can furthermore support only partial areas or the entire sole of the foot of a wearer of the shoe insole. For example, the shoe insole according to the invention can be provided in the form of a heel insole, which exerts a desired orthopedic effect, particularly in the heel area of ​​a wearer of the shoe insole.

[0023] The inventive method for manufacturing a shoe insole by injection molding, wherein the injection molding material is a composite material comprising at least one filler material corresponding to the base material of a covering with which the shoe insole is covered, comprises the following steps: [File: 103021350.docx / / SP85K53] Description

[0024] In a first step, a cover material is placed and fixed into one half of an open injection mold. This mold half can form the top surface of the orthotic insole three-dimensionally; that is, the forming surfaces of this mold half show a negative mold of the insole. This means that the forming surfaces of the mold half are three-dimensional and essentially depict a sole shape, allowing a negative mold of the sole to be formed on the finished orthotic insole. The mold half can also form the underside of the orthotic insole.

[0025] The injection mold is then closed, and in a further step, the composite material for forming the base body of the shoe insole is injected into the mold. Preferably, the injection material is injected from the side of the mold half facing away from the sole mold, so that it comes into contact with the underside of the cover material fixed in the mold, and the cover material is thereby pressed against the forming surface of the mold half containing the sole mold. A person skilled in the art will recognize that, according to the invention, the base body can also be formed on the upper side of a shoe insole by injection molding.

[0026] After the base body has been allowed to harden, the injection mold is opened in a further step and the covered shoe insole produced in this way is removed.

[0027] As already explained above in connection with the shoe insole according to the invention, the base body and the cover can be reliably joined together in a simple manner during injection molding using a composite material which has at least one filler material corresponding to the base material of a cover with which the shoe insole is covered.

[0028] The inventive method for manufacturing a shoe insole can further comprise a step of cutting the shoe insole by punching it out of the covering material. In this process step, the covering material protruding from the formed base body is separated in order to form the final shape of the shoe insole.

[0029] The inventive method for manufacturing a shoe insole can further combine the steps of shredding defective parts, sprues, sections according to a [File: 103021350.docx / / SP85K53] description

[0030] The invention involves cutting or other sorted production waste from the shoe insole according to the invention and reintroducing the shredded material as filler into the injection molding process for manufacturing covered shoe insoles. This allows, for example, the reuse of production waste from the covering material, the shoe insole according to the invention, or even the cured composite material, which not only saves material costs but is also environmentally friendly.

[0031] Furthermore, other shredded (reject) materials can also be used as filler in the injection molding process for manufacturing covered shoe insoles within the framework of the inventive process. These materials can, for example, be different from the production waste generated within the inventive manufacturing process. For instance, fibrous materials can be used as an additional filler in the injection molding process, which can cause interlocking or blocking between the existing structures of the cover and the base body in the cured base body. Materials that, for example, exhibit desired cushioning properties can also be used as an additional filler. By selectively choosing these other materials, the processes occurring within the inventive manufacturing process and the properties of the resulting shoe insole can be positively influenced.Furthermore, manufacturing costs can be reduced even further.

[0032] The preceding explanations of the orthopaedic shoe insole according to the invention and the inventive method for manufacturing such an orthopaedic shoe insole are further explained below with reference to the accompanying figures of preferred embodiments. The further explanations given are not intended to limit the inventive concept to these embodiments. They serve only for illustrative purposes. The figures show:

[0033] Figure 1 schematically shows a longitudinal section through an orthopaedic shoe insole according to a first embodiment according to the invention;

[0034] Figure 2 schematically shows a longitudinal section through an orthopaedic shoe insole according to a second embodiment of the invention;

[0035] Figure 3 schematically shows an orthopaedic shoe insole according to a third embodiment of the invention; [File: 103021350.docx / / SP85K53] Description

[0036] Figure 4 schematically shows a flowchart of the inventive method for manufacturing an orthopaedic shoe insole according to the invention; and

[0037] Figure 5 schematically shows a pair of orthopaedic shoe insoles according to the invention after removal from an injection mold.

[0038] The accompanying figures schematically show preferred embodiments of the invention, wherein identical components are provided with the same reference numerals for better readability.

[0039] Figure 1 schematically shows a longitudinal section through an orthopaedic shoe insole 1 according to a first embodiment of the invention. The orthopaedic shoe insole 1 according to this embodiment has a cover or top layer 2 on its upper surface facing the foot of the wearer of the shoe insole, which forms an anatomically shaped footbed. A base or support body 3 is arranged beneath this, providing anatomically and orthopaedically effective support to the foot of the wearer of the shoe insole. In this embodiment, the base body 3 is arranged over its entire surface beneath the cover 2 and thus supports the entire shoe insole 1. However, both the cover 2 and the base body 3 can also be provided only in one or more partial areas of the shoe insole 1 and thus at orthopaedically predetermined support areas, as shown in the embodiment depicted in Figure 3.

[0040] In this preferred embodiment, the cover 2 is made of a cork material, such as cork granules, which is bonded using a suitable binder, such as a resin. In this embodiment, only about 1-2% binder is added to bind the cork material. This results, for example, in a porous structure with an uneven surface, which, due to the honeycomb cell structure of cork, also provides improved adhesion conditions for the base body 3 that is injection-molded onto the underside.

[0041] Preferably, according to the present invention, the cover 2, to increase the wearing comfort of the shoe insole 1, is arranged on the upper side of the base body 3 and connected to or fixed to it without an adhesive layer. This is achieved according to the invention by manufacturing the base body 3 by injection molding, whereby the cover 2 is molded onto the base body 3 during the injection molding process. As already explained, the temperature and pressure conditions prevailing in the injection mold during injection molding lead to a permanent bond between the cured composite material of the base body 3 and the surface of the cover 2 by material interlock and / or form interlock. [File: 103021350.docx / / SP85K53] Description

[0042] In this embodiment, the composite material used to form the base body 3 comprises a thermoplastic polymer as a first base material and cork as a second base material, so that cork is present both as the main component of the cover 2 and as a base material or filler in the composite material used to form the base body 3. As mentioned above, the use of cork as the second base material of the composite allows, for example, the damping properties of the base body to be adjusted without modifying the first base material. Furthermore, production waste generated during the manufacture of the cover 2 and / or shoe insole 1 can be advantageously reused. Thus, in this embodiment, the cork material is present on both the cover 2 and the base body 3.

[0043] As an alternative to the embodiment just described, the cover 2 can also be made of other materials, such as rubber, leather, imitation leather, latex, foamed plastic (e.g., EVA foam), or the like, or it can be a textile covering. The advantageous bonding effects described above in connection with cork as the base material of the composite can also be achieved through the fiber structure of leather, imitation leather, or textile fiber products, or through the open-pore structure of a foamed plastic. The same applies to the use of shredded rubber, which may have a rough surface due to the shredding process.When selecting materials for cover 2 and the corresponding base material of the composite material, in addition to the aforementioned bonding properties and properties relating to wearing comfort and / or orthopedic effectiveness, care must be taken to ensure that only materials are used which are classified as safe for health by the health authorities in the individual countries and are therefore approved for use in healthcare.

[0044] The shoe insole 10 shown schematically in Figure 2, according to the second embodiment, is essentially identical in structure to the shoe insole 1 of the first embodiment, with the addition of a further cover 5 on the upper side of the shoe insole. In this embodiment, the further cover 5 is made of leather and can, for example, improve the cushioning properties and the appearance of the shoe insole. The further cover 5 can fix orthopedically effective additional parts, such as pads, metatarsal pads, wedges, or the like (not shown), to the shoe insole, so that these are located, for example, at orthopedically predetermined support areas. These additional parts can be arranged between the cover 2 and the cover 5 or incorporated into the cover 5. [File: 103021350.docx / / SP85K53] Description

[0045] be embedded within it. Such an additional reference can also be provided on the underside of the shoe insole.

[0046] The further reference 5 can alternatively be made of other materials than in the second embodiment shown. Reference is made to the materials mentioned above in connection with reference 2, which can also be used for the further reference 5.

[0047] Figure 3 schematically shows an orthopaedic shoe insole 100 according to a third embodiment of the invention in a bottom view. The shoe insole 100 shown in Figure 3 also corresponds in its construction essentially to the shoe insole 1 of the first embodiment, with a base body 300 of the shoe insole 100 being provided only in partial areas of the shoe insole 100, which can correspond to orthopaedically predetermined areas. As shown in Figure 3, the base body 300 of the shoe insole 100 is excluded in the heel area and extends into a midfoot and heel area, but not into a forefoot area. This allows the calcaneus of a wearer of the shoe insole 100 to be cushioned and softly supported in the vertical direction by the cover 2, while simultaneously holding and guiding the heel stably in the horizontal directions.In this case, the injection-molded base body 300 can be formed in the desired (partial) areas of the shoe insole by means of a suitably designed injection mold.

[0048] As an alternative to the embodiment shown in Figure 3, a shoe insole can also be provided according to the invention in which the base body is additionally or instead of the recess in the heel area, in the ball area and / or toe area.

[0049] Figure 4 schematically shows a flowchart for a method according to the invention for producing the shoe insole 1 shown by way of example in Figure 1 by injection molding.

[0050] In the process described here as an example, a web-shaped reference material S1 can first be prepared by, for example, mixing cork granules with a predetermined grain size with 1-2% of a suitable binder, such as resin, and then pressing them into shape.

[0051] In the next step S2, the web-shaped reference material is placed into one half of an open injection mold and fixed therein, whereby the shaping [File: 103021350.docx / / SP85K53] description

[0052] The surface of this injection mold half shows a negative mold of the footbed to be formed for the shoe insole to be manufactured. The positioning of the web-shaped cover material within the first injection mold half can be achieved, for example, with the aid of insertion pins provided in the injection mold, whereby insertion openings 6 (see Figure 5) incorporated into the web-shaped cover material can be hooked onto them. For example, the web-shaped cover material can be fixed in a vertically positioned first injection mold half with the injection mold open (not shown) by means of several clamping pins. Such a procedure is familiar to those skilled in the art, so further explanation is unnecessary here.

[0053] Subsequently, in step S3, the injection mold with the web-shaped cover material fixed within it is closed. In a further step S4, the injection molding material, in this embodiment a composite material comprising cork as a filler and a thermoplastic polymer as a continuous phase, is injected under pressure into the injection mold to form the base body 3. The injection molding material is injected from the side facing away from the mold half containing the sole shape, so that it comes into contact with the underside of the cover material fixed in the injection mold, thereby pressing the cover material against the forming surface of the mold half containing the sole shape.As mentioned above, the pressure and temperature conditions prevailing within the injection molding tool can achieve an improved material and form-fitting connection between the injection-molded base body and the cover.

[0054] After the base body has been allowed to harden in step S5, the injection mold is opened and the covered shoe insole blank is removed (see step S6 in Figure 5).

[0055] The person skilled in the art recognizes that the use of a web-like covering material is only one possible embodiment of the invention for introducing the covering material into the injection mold half. The covering material can also be inserted into the injection mold in a pre-cut form, e.g., as a covering section, particularly body flaps. The cutting or trimming can be carried out at any time before closing the injection mold, e.g., in a preceding work step. The covering sections can also be procured as pre-fabricated parts, such as flaps, sheets, or layers, e.g., as body flaps or flexible layers, and subsequently inserted and fixed into the injection mold half. The use of the covering material as a continuous material is not essential to the invention. Likewise, it is not essential to the invention whether the covering flap completely or only partially covers the mold cavity of the injection mold half. [File: 103021350.docx / / SP85K53] Description

[0056] The shoe insole blank produced as described above can be cut or punched into a shoe sole shape in a further processing step S7, resulting, for example, in the orthopaedic shoe insole 1 shown schematically in Figure 1. As already mentioned above, the resulting sections of the cover material and the casting parts can be shredded and then reused as filler material for the composite material used in the manufacture of the shoe insoles.

[0057] After such shaping by cutting or punching, the orthopaedic shoe insole produced according to the invention can be provided with a further covering on both the upper and the lower side. This can be done either by the manufacturer of the orthopaedic shoe insole according to the invention or later after possible processing, e.g., individual adaptation of the shoe insole by an orthopaedic technician or orthopaedic shoemaker.

[0058] As shown in Figure 5 in a view from below or from the gate side, the shoe insoles according to the invention can be manufactured using multi-cavity injection molding, in which several shoe insoles, here a pair of shoe insoles, are formed simultaneously in the injection mold. In the example shown in Figure 5, the shoe insoles 1, which are formed on a flap-like covering material, are connected to each other after injection molding via corresponding gate sections.

[0059] Reference symbol list

[0060] 1, 10, 100 shoe insole 51 step 1

[0061] 2 Reference 52 Step 2

[0062] 3,300 basic body 53 step 3

[0063] 54 Step 4

[0064] 5 Further reference 55 Step 5

[0065] 6 insertion openings 56 Step 6

[0066] 7 Sprue distributor 57 Step 7

Claims

[File: 103021085.docx / / SP85K53] Claims February 10, 2025 Claims 1. Orthopedic shoe insert with: a base body that is located on the underside of the shoe insole and is made of a composite material using injection molding, and a cover which is arranged on the top of the base body to increase the wearing comfort of the shoe insole and which is molded onto the base body by injection molding the base body, wherein a first base material of the composite material is a thermoplastic polymer and a second base material of the composite material corresponds to a material of the cover.

2. Orthopedic shoe insole according to claim 1, wherein the thermoplastic material is TPU (thermoplastic polyurethane), EVA, polyethylene, polypropylene or a mixture thereof.

3. Orthopedic shoe insole according to one of claims 1 or 2, wherein the material of the cover is cork, rubber, leather, artificial leather, latex, foamed plastic, or a textile cover.

4. Orthopedic shoe insole according to one of the preceding claims, wherein the base body supports only one or more partial areas of the shoe insole or the entire shoe insole.

5. Orthopedic shoe insole according to one of claims 1 to 3, wherein the cover only covers partial areas or the entire base body.

6. Orthopedic shoe insole according to any one of claims 1 to 3, wherein the shoe insole is provided with at least one further covering which is provided at least in partial areas on the upper or lower surface of the shoe insole with the covering molded onto the base body. [File: 103021085.docx / / SP85K53] Claims 10. February 2025 7. Orthopedic shoe insole according to claim 6, wherein the further cover fixes orthopedically effective additional parts, such as pads, pads, wedges, or the like, to the shoe insole.

8. Orthopedic shoe insole according to one of the preceding claims, wherein the shoe insole supports only partial areas or the entire sole of the foot of a wearer of a shoe insole.

9. Method for manufacturing a shoe insole by injection molding, wherein the injection molding material is a composite material comprising at least one filler material corresponding to the base material of a covering with which the shoe insole is covered, the method comprising the steps of: Inserting and fixing a cover material into one half of an open injection mold; Closing the injection mold; Injecting the composite material to shape the base body of the shoe insole; Allowing the base body to harden; Opening the injection mold, and Removal of the covered shoe insole; 10. Method for manufacturing a shoe insole according to claim 9, further comprising the step of cutting the shoe insole, e.g. by punching out the shoe insole from the covering material.

11. Method for manufacturing a shoe insole according to claim 9 or 10, further comprising the steps of shredding defective parts, sprues, sections after cutting or other sorted production waste and reintroducing the shredded material as filler for the injection molding process to manufacture covered shoe insoles.

12. Method for manufacturing a shoe insole according to claim 11, further comprising the supply of other shredded (reject) materials as filler for injection molding to manufacture covered shoe insoles.

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