Orthopedic PUR foam insole blanks

Abstract

An orthopedic PUR foam insole blank (1) has at least one buffer body (10) and a PUR support body (6), which supports the foot and is three-dimensionally molded in a RIM process. The PUR support body (6) has a shoe-side lower side (8) and a foot-side upper side (7), on which an anatomically shaped orthopedic foot bed (3) is formed. The at least one buffer body (10) consists of a prefabricated two-dimensional PU sheet (15) without a carrier layer and produced by solidification, extrusion or from a polyurethane dispersion mixture. The at least one buffer body (10) is fixed to the upper side (7) and / or the lower side (8) of the PUR support body (6) by foaming with PUR foam (5) in a RIM foaming mold during the expansion of the RIM foam.

Description

Technical Field

[0001] The present invention relates to an orthopedic foam plastic insole blank having a three-dimensional PUR support body molded using the RIM process, with at least one cushioning element arranged on its upper side. Furthermore, an orthopedic footbed is formed on the upper side of the PUR support body. The lower side of the PUR support body faces the shoe sole. The present invention also relates to a method for manufacturing such an insole blank. Background Art

[0002] Known from the prior art are orthopedic PUR foam insole blanks manufactured using the RIM process, which have a PUR base or support. The function of the base or support is to support and guide the foot in an anatomically and orthopedically functional manner. To this end, the base or support is made of a flexible but relatively strong PUR foam. In addition to providing orthopedic support, it must also provide biological cushioning, for example, during walking, so that sudden load changes are not transmitted violently to the foot skeleton. A cushioning body is provided on the insole to further dampen foot movements and to adjust or balance the sole of the foot, or to reduce pressure peaks on particularly sensitive areas of the sole. Such a cushioning body is softer than a PUR support and can therefore better adapt to the sole of the foot. The better the interaction between the support and the cushioning body or the insole covering material, the better the orthopedic requirements can be met.

[0003] The PUR base or support is typically formed into the shape of the insole by foaming a polyol with isocyanate in a RIM foaming mold. In this process, two reactive starting components (polyol and isocyanate) are added to an open mold (usually a two-part mold), the cavity of which assumes the shape of the shoe sole. Such RIM foaming molds are well known and are used to manufacture orthopedic insole blanks. However, PUR bases or supports produced via the RIM foaming process, especially when manufactured using only one material hardness, do not provide optimal orthopedic effect or wear comfort across all areas of the foot sole. Furthermore, the appearance of such RIM blanks is not always attractive, but this can be improved by covering the support with a cushioning or covering material.

[0004] For example, prior art insole blanks are described in documents DE 10 2018 206 906 A, EP 3 981 279 A, ​​EP 3 708 018 A.

[0005] Because orthopedic insole blanks have varying requirements for support and cushioning properties, particularly in different areas of the sole, they generally cannot be manufactured from just one material / hardness. For example, if different RIM foams are used, undefined and unpredictable support and cushioning properties can occur in the transition areas of the foams, depending on how the foams flow toward each other during the foaming process. This, along with the formation of material fronts due to the foams, cannot be fully reproduced in a process-stable manner to maintain precise sole area limitations. For this reason, PUR supports are often equipped with cushioning elements and other covering and facing materials or orthopedic components to improve the desired orthopedic support and cushioning properties.

[0006] Therefore, various sole areas of the support body (for example, the forefoot or heel) are typically designed with recesses to accommodate cushioning material, for example, to cushion and soften the heel bone vertically while maintaining heel stability and guiding it horizontally. Alternatively, reinforcements are inserted or attached to the longitudinal arches to reinforce the orthopedic insole blank in the corresponding areas for orthopedic function. At the same time, with the help of covering materials, attempts are made to optimize the desired wearing comfort properties in these areas. The goal here is to achieve the conflicting objectives of stiffness and softness without creating edges or rigid elements that reduce wearer comfort or diminish the orthopedic effect.

[0007] To achieve an orthopedic effect while simultaneously achieving the desired wearing comfort and improving the appearance, a PUR support is typically provided with or covered with a cushioning material or covering material that exhibits the desired properties in terms of cushioning, wearing comfort, and appearance. However, commonly used cushioning / covering materials can negatively impact the orthopedic effect of the PUR support, and vice versa. This is due to the fact that conventional facing and covering materials used in the prior art typically have a textile carrier layer or an adhesion-promoting carrier layer to enable the cushioning and / or covering material to bond to the PUR foam material of the support and / or to maintain the cushioning and / or covering material's stability and wear resistance.

[0008] However, these carrier layers or adhesion-promoting layers not only affect the inherent properties of the various components of the insole in the contact area between the support and the cushioning material or covering material, but also distort the force transmission from the foot to the sole or change the expected cushioning effect. This is due to the interaction between the carrier layer and / or adhesive layer of the cushioning body / covering material and the orthopedic functional support made of PUR foam. For example, a fabric carrier layer is disadvantageous in the sole area where good cushioning is to be achieved, because the inherent properties of the fabric are tension-rigid in the longitudinal direction of the line (i.e., in the fabric plane), which reduces the cushioning in at least this direction. As a result, the desired support and cushioning properties of the PUR support or cushioning body of the bottom layer cannot be fully utilized, because the fabric layer prevents the foot (e.g., the heel bone) from sinking into the cushioning layer. A similar situation applies to the metatarsophalangeal joint area, where good cushioning should be regularly achieved. However, if the carrier or adhesive layer has tension-rigidity or even rigidity in one direction, the cushioning and / or damping properties of the cushioning material applied by means of the carrier or adhesive layer are also reduced.

[0009] On the other hand, elastic bonding layers in areas such as the longitudinal arches can impair the secure connection between the covering material, the adhesive body and / or the orthopedic insert and the support body, as they reduce the stiffness in this area. This means that the combination of the support body with the applied cushioning or covering material and the carrier layer or adhesion-promoting layer is not always an optimal compromise.

[0010] Another challenge for cushioning and overlay materials is their wear resistance: achieving high levels of wear resistance while maintaining good cushioning and comfort. These contrasting properties, between wear resistance and good cushioning, often lead to multi-layered overlays or composite materials, which often represent a compromise between desired properties. The foot-facing surface may be wear-resistant but lack cushioning, or vice versa. Consequently, high cushioning performance often goes hand-in-hand with low wear resistance.

[0011] Another challenge for cushioning and covering materials is their ability to bond with the PUR material of the support. Textile materials (e.g., fleece or similar materials) are penetrated by the uncured PUR material during the foaming process and, after curing, form a more or less rigid intermediate layer. This impairs the elasticity, damping properties, and flexibility of the cushioning or covering material, both for the PUR foam of the support and for the boundary layer between the covering material and the PUR foam, at least on the upper side of the PUR support or the lower side of the cushioning body. Furthermore, the pressure loads or forces transmitted by the foot to the insole are only indirectly and in a distorted manner, making selective cushioning, for example in the forefoot area, particularly in the metatarsophalangeal joint area, virtually impossible. Summary of the Invention

[0012] The object of the present invention is therefore to provide a foamed plastic insole blank, the support of which is produced using a RIM foaming process and which has at least one buffer body or covering material on its upper side and / or on its lower side facing the foot, which does not negatively affect the supporting properties of the support body and improves the cushioning properties of the support body. The buffer body should also be wear-resistant and have the necessary elasticity so that even transient pressure loads on the support body of the insole blank can be reliably transmitted. In addition, a cost-effective insole blank is to be provided, whereby the production of the PUR support body and the connection between the support body and the at least one buffer body / covering material, in particular, are not carried out in separate process steps.

[0013] The problem according to the invention is solved by an orthopedic PUR foam shoe insole blank according to claim 1, preferred embodiments being given in the subsequent dependent claims. The problem according to the invention is further solved by a method for producing an orthopedic PUR foam shoe insole blank according to claim 12, preferred embodiments of the method according to the invention being specified in the subsequent dependent claims.

[0014] The orthopedic PUR foam insole blank according to the present invention has a PUR support body that is three-dimensionally formed using a RIM process and supports the foot. The PUR support body has a lower side portion on the shoe side and an upper side portion on the foot side, on which an anatomically shaped orthopedic foot bed is formed. At least one buffer body is arranged on the upper side and / or lower side portion on the foot side of the PUR support body, and the at least one buffer body is foamed onto the support body during a reactive PUR foaming process. In the remainder of this description of the invention, the term "buffer body" should also be understood to refer to covering materials and finishing materials, because in addition to visually improving the appearance of the insole blank, these materials also achieve a more or less strong buffering effect depending on the material thickness. Therefore, the terms "buffer body," "covering material," and "top material" should be understood as synonymous and interchangeable, depending on the requirements for the cushioning, wearing comfort, and / or decorative properties of the PU sheet.

[0015] In the further description of the present invention, the insole blank according to the present invention is also referred to as simply "insoles" due to the fact that, for example, the insole blank removed from the RIM foaming mold can also be directly inserted into a shoe after being cut to size, thereby replacing the missing footbed. However, in most cases, the insole blank according to the present invention is intended to be further processed by an orthopedist (e.g., a shoe orthopedist) in order to adapt it to the foot of the wearer of the shoe and also to the shoe itself, in particular, individually. Since the improvements over the prior art achieved by the present invention apply to both insole blanks and shoe inserts, these terms may also be used synonymously for the sake of convenience.

[0016] The material used for the cushioning body according to the present invention (if its material thickness is relatively low, it can also be referred to as a facing material or covering material) is a substantially two-dimensional polyurethane sheet produced from a polyurethane starting material without a carrier layer by a coagulation process, an extrusion process, or from a dispersion mixture. The polyurethane sheet used according to the present invention has no carrier layer, in particular no textile used as a carrier. The polyurethane surface material used according to the present invention is often referred to in expert circles as non-woven artificial leather based on polyurethane (PU).

[0017] The PU surface material according to the present invention is characterized by the fact that its length and width dimensions are significantly greater than the material's thickness. It is not absolutely necessary for the material's thickness to be constant in width and / or length, although this is the preferred embodiment in most cases. The term "surface material" is also intended to convey the fact that the surface dimensions of the cushioning body or covering material do not necessarily correspond to the length and width dimensions of the insole blank, but both the length and width dimensions can be significantly larger or smaller in the surface dimensions. In the thickness direction, the PU surface material can be as thin as a film or, for example, a few millimeters or centimeters thick, to meet the performance requirements of the cushioning body.

[0018] In particular, it is conceivable that the PU surface material is delivered to and used by the manufacturer of the shoe insole blank according to the present invention as a sheet, strip, continuous material or roll material, and that the PU surface material is merely cut into an appropriate length or cut into an appropriate size before being inserted into the RIM foaming mold, i.e., specifically prepared for insertion into the foaming mold.

[0019] In contrast to PUR foams with PUR supports, which are produced in the so-called reactive foaming process, i.e. by bringing reactive polyols together with reactive isocyanates into a RIM foaming mold to form and shape the polyurethane foam, the covering material or facing material (= PU sheet) used according to the invention is processed from fully reacted polyurethane (PU) in liquid or solid form by coagulation, dispersion and subsequent drying, or by extrusion to form a non-woven PU artificial leather, which does not have a carrier layer, in particular no textile carrier layer.

[0020] During the RIM foaming process, the PU sheet produced in this manner can be foamed directly with the PUR foam produced in the RIM foaming mold and fixed in place. This is because the two polyurethane materials bond to each other during the curing of the PUR foam without forming a rigid or solidified interface layer. When a carrier layer (particularly a textile carrier layer) is applied to the surface material, such an interface layer forms because the still-soft PUR foam penetrates the carrier layer before the resulting PUR foam hardens in the RIM foaming mold, creating a PUR foam reinforced by the carrier layer in the interface layer between the support and cushioning body. In the interface region, both the support and cushioning body still have (significantly) reduced elastic properties, which negatively impacts not only the orthotic effect of the insole but also the wearing comfort. For example, due to the crosslinking / rigidification of the interface, point loads on the support body can no longer be supported at specific points but are instead distributed over a wider area. This results in an overall harder or softer feel to the support or cushioning, despite the constant hardness of the PUR foam used.

[0021] Even though urethane is not a monomer of polyurethane, no rigid or hardened interface forms when the two PU materials are connected, as both PU materials contain urethane as a functional group. Consequently, the properties of the two PU materials are largely retained within the area of ​​the contact surface of the two sole bodies, allowing for a soft, and in particular stepless, transition from the material properties of the support body to the material properties of the buffer body in the thickness direction of the insole. This provides for particularly comfortable wearing comfort without compressing the supporting properties of the PUR foam of the support body or the buffering properties of the PU covering material (buffer body). Overall, this means that forces can be continuously transferred to the insole and buffered without a rigid interface. As a result, the load transfer, support, and buffering functions of the insole can be calculated and predicted more evenly and better, allowing the insole blank according to the invention and the insole manufactured therefrom to be more precisely and better adjusted to the needs of the wearer of the insole.

[0022] Furthermore, orthopedic insole blanks can be individually adapted to the foot or sole of the person wearing them. This is typically achieved by using materials that are, if not milled, at least ground for the support and cushioning bodies. If the cushioning bodies of the prior art, which have a textile carrier layer, are milled and / or ground by orthopedic shoe manufacturers for an individual fit, the ground areas will inevitably have a worn appearance. The use of the non-woven PU sheet according to the present invention avoids the unsightly appearance of such ground insoles, as no grinding lines extend from the insole. Consequently, the (individually) adapted and processed insole blanks according to the present invention also have a more attractive appearance than conventional insole blanks known from the prior art.

[0023] According to the present invention, it is not mandatory that the covering material or the cushioning body consists of a polyurethane (PU) sheet, but the inventors are not aware of any other suitable covering material or cushioning material that can be connected to the reaction foamed polyurethane (hereinafter referred to as PUR) without a carrier layer, so that no rigid or solidified interface is formed when the PUR is foamed on or in the RIM foaming mold or after the PUR foam plastic is cured.

[0024] When selecting materials, it's also important to ensure that only materials are used that have been classified as harmless to health by the respective national health authorities and are therefore approved for use in the medical industry. For example, polyvinyl chloride (PVC) is not approved for shoe insoles in Germany, but PVC can also be used to produce artificial leather. Therefore, the present invention is described based on PU artificial leather as the preferred material. However, if PVC is ever approved for shoe insoles, the present invention can also be applied mutatis mutandis to PVC artificial leather. If PVC is approved as a covering material for orthopedic functional shoe insoles in other countries outside of Germany, the term PU sheet according to the present invention should also be understood in these countries to refer to PVC artificial leather without a carrier layer.

[0025] As is readily apparent to those skilled in the art, a PU sheet without a carrier layer can be made thinner than a covering material with a (textile) carrier layer. This effect is particularly pronounced if a cushioning body is to be formed on a covering material that conforms to the foot, since a rigid carrier layer should be positioned as far away from the sole of the foot as possible to ensure that the cushioning body conforms to the foot. According to the present invention, such a rigid carrier layer is not required, which enables the cushioning body to be made thinner. This effect is further enhanced by the flexibility of the PUR support body, since it no longer forms a rigid counter-support, such as a hardening interface or intermediate layer. This is advantageous, for example, for insoles for diabetics, since the material hardening transition can be cushioned with a thinner cushioning body, thereby allowing the insole as a whole to be made thinner. However, thinner insoles are also preferred for street, sports, leisure and / or work shoes, especially if the insoles of such shoes are not replaceable and are inserted separately into the shoe. This can, for example, prevent a heel held by the shoe from being lost due to the additional insole.

[0026] The use of a covering material or a buffer body without a carrier layer according to the invention is further preferred for an insole whose support body is provided with a recess, which is arranged, for example, in the heel area or in the forefoot area and into which a soft buffer material is introduced. Here, in the case of a covering material used according to the invention without a carrier layer, both the PUR foam plastic material of the support body and the buffer material inserted into the recess can fulfill their function over the entire material thickness and are not inhibited by orthopedic hindering hard interfaces. As a result, the support body with the buffer body inside can also be made thinner in the thickness direction of the insole, since there is no rigid interface at all. By using a PU sheet without a carrier layer as a covering material or buffer material for the insole according to the invention, the load on the foot and the force transmission from the foot to the sole can be transmitted directly via the orthopedic functional material and are not distorted by the rigid interface.

[0027] The cushioning body or covering material only partially or completely covers the upper and / or lower side of the insole blank. Since the two PU materials can be easily joined together, considerable design freedom is provided, particularly with regard to the arrangement of the cushioning and support areas. Thus, according to the present invention, the cushioning body can assume the shape of the entire sole, while the support body is formed only in the orthopedic support area. Those skilled in the art will also recognize the possibility of a reverse embodiment, in which the cushioning body is formed only in the area requiring cushioning of the sole.

[0028] This also allows for embodiments in which multiple buffer bodies and covering materials are used, both made from the PU sheet according to the present invention. For example, the buffer body extends through a recess in the covering material, or the buffer body is secured to the support body by means of the covering material. This can be achieved, for example, in a sandwich configuration, where the support body secures the buffer body to the covering material, and vice versa. This means that the buffer body can be completely or only partially covered by the covering material, whereby both the buffer body and the support body can be submerged and / or visible through recesses in the covering material.

[0029] According to the present invention, a RIM foaming process is used to produce insole blanks. A RIM foaming mold, typically made of two foaming mold halves, is used. The first foaming mold half forms the upper side of the support body, facing the foot, and features a three-dimensional footbed. The second foaming mold half forms the lower side of the support body, facing the shoe. Therefore, the shaped surfaces of both mold halves represent a negative image of the upper or lower side of the support body. During RIM foaming, the PUR foam-forming reagents (polyol and isocyanate) are introduced in liquid form into the lower foaming mold half (often referred to as the second foaming mold half) via a mixing head. When the two reagents come into contact, they react exothermically to form the PUR foam. To form the desired molded body, in this case, the support body, the RIM foaming mold has a closed cavity. This cavity is formed by placing the first foaming mold half (typically the upper mold half) onto the second foaming mold half. After the two foaming mold halves are assembled, they are locked together so that the expanding PUR foam cannot press open the RIM foaming mold. The added reagents can expand in the mold cavity until they are used up. After the curing time has elapsed, the foamed plastic body (in this case, the support body) produced in this way can be removed from the foaming mold.

[0030] For the production of the shoe insole blank according to the present invention, the PU sheet of the buffer body is inserted into the first foaming mold half when the foaming mold half is open, and is fixed or attached to the first foaming mold half so that the PU sheet at least partially covers the shaping surface of the first foaming mold half, and the PU sheet is at least bonded to the first foaming mold half during the closing process of the foaming mold and does not fall off.

[0031] As mentioned above, before the foaming mold is closed, the starting components (i.e., polyol and isocyanate) are introduced in liquid form into the second half of the foaming mold with the help of a so-called mixing head. When the two reagents come into contact, they begin to chemically react with each other to form the PUR foam and expand, as is well known in the prior art and as described above. Therefore, it is necessary to close the foaming mold as soon as possible after the reagents are introduced. This is usually done in a guided linear and / or folding movement. The closed mold is then locked or maintained. If the PU sheet is too large to extend beyond the forming surface, this locking force or holding force can be used to ultimately keep the PU sheet inserted into the first half of the foaming mold. For example, this will clamp and fix the PU sheet in the parting plane of the two mold halves.

[0032] Since the reagents for the PU foam had already been introduced into the lower half of the foaming mold before the foaming mold was closed and can now expand in the mold cavity to form the PU foam, the PU sheet in the closed foaming mold is now also foamed by the expanded PU foam. This forms a material bond between the PU sheet and the PU foam. At the same time, the PU sheet is pressed against the shaping surface of the first half of the foaming mold by the PU foam being formed and deformed into the shape of a three-dimensional foot bed, which is formed by the shaping surface of the first half of the foaming mold. After the foaming process is completed, that is, after the reaction of the two initial components is completed, the PUR foam has hardened and the foaming mold can be opened. The shoe insole blank of the foam produced according to the present invention can now be removed from the foaming mold.

[0033] Depend on how PU sheet is cut and fixed, may need PU sheet to be cut into the shape of sole, so that it is further processed by orthopedic specialist.As mentioned above, for example when changing insole, also such cut insole blank can be directly inserted in the shoe.

[0034] According to the present invention, there are various possibilities for inserting the PU sheet or the cushioning body. One is to use a peelable protective film that is bonded to the cushioning body, with which the cushioning body / PU sheet is inserted into the first foaming mold half, with the protective film facing the shaping surface. The protective film is at least lightly bonded to the interior of the first foaming mold half so that it does not separate from the first foaming mold half when the foaming mold halves are closed. When the foaming mold is closed, the protective film with the attached PU sheet can then be clamped in the parting plane formed between the two foaming mold halves and hold the cushioning body in its intended orthopedic functional position.

[0035] After the RIM foaming process, the protective film can be easily removed from the insole blank produced in this way, because it is removably attached to the cushioning body. According to the invention, it is not important when the protective film is removed, but this should be done before the wearer of the insole starts using it.

[0036] Another option is to cut the PU sheet wide enough so that it is clamped directly in the mold parting plane between the two mold halves when the foaming mold is closed. This is particularly preferred if the PU sheet is relatively thin, as it can avoid negative effects on the parting plane. At the same time, the PU sheet seals the parting plane, preventing any PUR foam from escaping the mold cavity.

[0037] In another embodiment of the manufacture of the insole blank according to the present invention, the protective film can also be a covering material remaining on the insole blank, for example, previously bonded to a PU sheet.

[0038] In another embodiment, in which a cushioning body made of a PU sheet is to be applied to the RIM support body according to the present invention, a covering material or protective film is inserted into the first half of the foaming mold to which the cushioning body is bonded or attached. The cushioning body does not need to cover the entire footbed, but can be arranged only in a partial area of ​​the finished shoe insole. In this embodiment, the covering material or protective film is used only to position or fix the cushioning body or another orthopedic functional component in its intended orthopedic position. In this case, the cushioning body is thus held in its intended orthopedic position in the RIM foaming mold by the covering material during the foaming process (i.e., during the expansion phase of the foamed plastic). Similar to the cushioning body described above, other orthopedic functional components known to orthopedists (such as pads, support wedges, heel wedges, and similar orthopedic components) can also be fixed in their intended positions in the finished shoe insole with the help of a covering material or PU sheet.

[0039] In another preferred embodiment of the present invention, the injection molded part is injected onto the cushioning body before the cushioning body is inserted into the foaming mold. To this end, the PU sheet is first introduced into the injection mold, or the PU sheet is fixed in the injection mold, for example by suspending the PU sheet, so that the injection molded part is injected onto the PU sheet in the desired and predetermined corrective position, and the injection molded part and the PU sheet can be transferred together to the first foaming mold half of the RIM foaming mold, so that the injection molded part is also held in the predetermined corrective position in the RIM foaming mold by the cushioning body (i.e., by the PU sheet).

[0040] Preferably, the injection-molded portion, which is injected onto the cushioning body made of the PU sheet, is arranged on the lower side of the insole blank. This is because such injection-molded portions are generally made of a relatively hard material, enabling them to provide good support for the foot. To ensure that the upper side of the insole blank according to the present invention still exhibits soft and elastic cushioning properties, the PUR support body is preferably arranged above the injection-molded portion, i.e., on the upper side, so that the support body can be regarded as a kind of cushioning body for the injection-molded portion.

[0041] According to the present invention, the injection-molded part arranged on the cushioning body or the PU sheet is preferably inserted into the second foaming mold half, the shaping surface of which forms the lower side of the support body. Depending on whether the injection-molded part can be processed on the molded insole blank, the injection-molded part can be arranged to face the shaping surface in the second foaming mold half or away from the shaping surface. If the injection-molded part faces the mold cavity, it is at least partially covered by the PU sheet in the RIM-molded insole blank, because the cushioning body made of the PU sheet keeps the injection-molded part in the desired predetermined position and facing the shaping surface of the second foaming mold half during RIM foaming. On the contrary, when the injection-molded part faces the shaping surface of the second foaming mold half, after removing the insole blank, the injection-molded part is visible on the lower side of the insole blank and can be processed, for example by an orthopedic specialist.

[0042] While the method according to the invention for producing a shoe insole blank has been described above with reference to the use of only a single PUR foam, as known to the person skilled in the art, the method can also be carried out in a similar manner with two or more PUR foams, preferably with different material hardnesses. The starting materials for two or more PUR foams can be produced simultaneously in the same foaming mold. For this purpose, different mixtures or different amounts of polyols and isocyanates are introduced simultaneously at different points in rapid succession into a second foaming mold via a plurality of mixing heads or a single mixing head and can then be expanded in parallel in the closed foaming mold. If no mechanical flow boundary is provided, the resulting material front is formed depending on the reaction speed of the individual PUR foams produced. Consequently, it is difficult to form a clear, reproducible material front, in particular when the PUR foams enter one another and mix in some areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above description of the orthopedic PU insole according to the present invention and the method for producing such an orthopedic insole blank according to the present invention will be explained in more detail below with reference to the accompanying drawings of preferred embodiments. The further explanations provided are not intended to limit the concept of the present invention to these embodiments. They are for illustrative purposes only. The drawings show:

[0044] Figure 1 schematically shows a longitudinal section through an orthopedic shoe insole blank according to the prior art;

[0045] Figure 2 shows schematically a longitudinal section through an orthopedic shoe insole blank according to a first embodiment of the invention;

[0046] Figure 3 shows schematically a longitudinal section through an orthopedic shoe insole blank according to a second embodiment of the invention;

[0047] Figure 4 shows schematically a longitudinal section through an orthopedic shoe insole blank according to a third embodiment of the invention;

[0048] Figure 5 is a schematic perspective view of a fourth embodiment of an orthopedic shoe insole blank according to the present invention;

[0049] Figure 6 is a schematic perspective view of a fifth embodiment of an orthopedic shoe insole blank according to the invention. DETAILED DESCRIPTION

[0050] Figure 1 A shoe insole 100 known from the prior art is schematically shown in longitudinal section. The shoe insole 100 shows an upper footbed 3 formed on the upper side 7 of a support body 6 made of PUR foam 5. The footbed is covered with a cushioning body 10, with a carrier layer 4 serving as a connection-promoting layer that holds the cushioning body 10 on the support body 6. In this case, the adhesion-promoting layer 4 extends over the entire surface of the shoe insole 100.

[0051] Figure 2 The shoe insole blank 1 according to the invention is also shown in a schematic longitudinal section. The shoe insole blank 1 according to the invention also shows a footbed 3, which is arranged on the upper side of a support body 6 formed from PUR foam 5. The support body 6 of the shoe insole blank 1 according to the invention is also covered with a buffer body 10, which is however directly connected to the support body 6 by a material-to-material bond without any adhesion-promoting or connecting carrier layer. According to the invention, the support body 6 can be omitted. Figure 1 The adhesion-promoting layer 4 known from the prior art is shown, because the material of the cushioning body 10 bonds with the RIM foam 5 during the RIM foaming of the support body 6. Thus, in its simplest embodiment, the insole blank 1 according to the invention has two layers, whereas previously known insole blanks 100 must have at least three layers due to the presence of the carrier layer 4. The advantages of a two-layer design of the insole blank have already been explained above in the general description of the invention.

[0052] Figure 3A second embodiment of the insole blank according to the invention is shown, in which the damping body 10 is arranged on the lower side 8 of the support body 6, i.e., the damping body 10 forms the lower side 18 of the insole blank 1. In this embodiment, the upper side 7 of the support body 6 simultaneously forms the upper side 17 of the insole blank 1. As will be readily appreciated by a person skilled in the art, the upper side 7 of the support body 6 can be provided with an additional covering material 25, which can also be applied subsequently to customize the insole blank, for example by grinding or milling. Figure 3 The shoe insole blank 1 schematically shown in FIG. 1 also shows a support portion 19 arranged in the heel region 13 . Support portion 19 is preferably injection molded onto the cushioning body 10 before the cushioning body 10 is inserted into the foaming mold half that forms the shoe-facing underside 18 of the shoe insole blank 1. According to the present invention, injection molded portion 19 is injected onto the PU sheet 15 of the cushioning body 10 so that it can be inserted and secured together with the PU sheet 15 in the RIM foaming mold. This allows injection molded portion 19 to be held in the desired, predetermined position by the cushioning body 6 during RIM foaming. As described above, when the RIM foaming mold is closed, the cushioning body 10 can, for example, be clamped in the parting plane of the two foaming mold halves. This prevents both the cushioning body 10 and the injection molded portion 19 from sliding during expansion of the PUR foam in the RIM foaming mold, and the injection molded portion 19 is securely held in the desired, predetermined orthopedic functional position.

[0053] Figure 4 To Figure 3 The embodiment variant of FIG shows a third embodiment of an insole blank 1 according to the invention having an internal injection-molded portion 19, which is arranged on the lower side 8 of the support body 6. In this embodiment, the PU sheet 15 of the cushioning body 10 forms the lower side 18 of the insole blank 1. Figure 3 As shown in the embodiment of FIG, the support body 6 is arranged on the upper side 17 of the insole blank 1, and the support body 6 can be provided with another buffer body 10 and / or a covering material 25, for example Figure 5 and Figure 6 As shown in other embodiments. Figure 3 In contrast to the embodiment of Figure 4 In the embodiment of the present invention, the injection molded portion 19 of the PU sheet 15 injected into the cushioning body 10 is inserted into the RIM foaming mold together with the cushioning body 10 so that the injection molded portion 19 faces the mold cavity during RIM foaming. The cushioning body 10 covers the shaping surface of the second RIM foaming mold half, which forms the lower side 18 of the insole blank 1 facing the shoe. Figure 4The exemplary embodiment of FIG shows the injection-molded part 19 completely covered by the PU sheet 15 of the cushioning body 10, but this is not mandatory. It is also conceivable that the PU sheet has a recess 16 through which the injection-molded part 19 emerges on the surface and can be visually processed there, for example by an orthopedist.

[0054] Figure 5 A fourth embodiment of a shoe insole blank 1 according to the invention is shown in perspective and exemplary manner, wherein, for example, Figure 2 The insole blank 1 is covered with another covering material 25. In the covering material 25 (which can also be a PU sheet, but does not necessarily have to be a PU sheet), one or more recesses 16 are arranged in the toe area 11, the midfoot area 12, and the heel area 13 of the sole of the foot. The cushioning body 10 is in direct contact with the sole of the wearer's foot through these recesses 16. In this case, the cushioning bodies 10 can be connected to each other under the additional covering material 25, or the cushioning bodies 10 can be separate cushioning bodies 10 that are separately connected to the support body 6. Separate cushioning bodies 10 can be used to individually adapt the cushioning and support requirements required for the orthosis in each individual area. For example, a softer cushioning body 10 can be used in the metatarsophalangeal joint area in the transition from the forefoot area 11 to the midfoot area 12, for example, a softer cushioning body 10 than that used for the big toe.

[0055] from Figure 6 Those skilled in the art will recognize that Figure 4 The placement and fixing of the inserts (in particular, the orthopedic functional components 9, such as pads, heel wedges, longitudinal arch supports, etc.) is carried out similarly, and are at least partially visible through the recesses 16 arranged in the cushioning body 10. Also included are embodiments in which the orthopedic functional components 9 are completely covered by the cushioning body 10. With this embodiment, the orthopedic functional components 9, which cannot be materially bonded to the PUR foam, can be securely fixed as inserts to the insole blank 1 according to the invention by means of the cushioning body 10 made of a PU sheet 15 that can be materially bonded to the support body 6.

[0056] As indicated above, without departing from the concept of the present invention, Figures 1 to 6The various embodiments can be combined with one another. According to the invention, in particular, it is possible to produce an insole blank that displays one or more cushioning bodies 10 both on the upper side 17 and on the lower side 18 of the insole blank 1. In this case, the PU sheet 15 of the one or more cushioning bodies 10 or the PU sheet of the covering material 25, which is additionally applied to the upper side 17 and / or lower side 18 of the insole blank 1 according to the invention, can have a recess 16 through which the injection-molded portion 19 and / or the PU sheet 15 of the one or more cushioning bodies 10 are visible. A person skilled in the art will recognize a large number of possible combinations, all of which are connected by the inventive concept of using a PU sheet 15 without a carrier layer as the cushioning body 10.

[0057] List of reference numerals

[0058] 1 Orthopedic shoe insole blank

[0059] 3-foot bed

[0060] 4 Carrier layer

[0061] 5 PUR foam plastic

[0062] 6 PUR support

[0063] 7 Upper side of the support

[0064] 8 Lower side of the support body

[0065] 9 Orthopedic functional components (inserts)

[0066] 10 Buffer

[0067] 11 Forefoot area

[0068] 12 midfoot area

[0069] 13 Heel area

[0070] 15 PU sheet

[0071] 16 recess

[0072] 17 Upper side of the insole blank

[0073] 18 Lower side of the insole blank

[0074] 19 Injection molded parts

[0075] 25 Covering material

[0076] 100 Insole of footwear according to prior art

Claims

1. An orthopedic PUR foam insole blank (1), the insole blank (1) comprising at least one buffer body (10) and a PUR support body (6), the PUR support body (6) being three-dimensionally formed in a RIM process, the PUR support body (6) supporting the foot and having a shoe-side lower side (8) and a foot-side upper side (7), an anatomically shaped orthopedic foot bed (3) being formed on the upper side (7), wherein the at least one buffer body (10) consists of a prefabricated two-dimensional PU sheet (15) without a carrier layer and produced by solidification, extrusion or from a polyurethane dispersion mixture, and wherein the at least one buffer body (10) has been fixed in a RIM foaming mold during the expansion of the RIM foam to the upper side (7) and / or the lower side (8) of the PUR support body (6) in a material-integrated manner by foaming with PUR foam (5).

2. The shoe insole blank (1) according to claim 1, wherein: The at least one buffer body (10) only partially covers the upper side (17) of the insole blank (1), or completely covers the upper side (17) of the insole blank (1), or the PUR support body (6) is only arranged in a partial area of ​​the insole blank (1).

3. The shoe insole blank (1) according to claim 1 or 2, wherein: A covering material (25) is applied to the PUR support body (6) and / or the at least one buffer body (10), the covering material (25) covering the buffer body (10) or the covering material (25) having a recess (16) through which the buffer body (10) and / or the PUR support body (6) are at least partially visible.

4. The shoe insole blank (1) according to claim 1 or 2, wherein: Two or more buffer bodies (10) are fixed to the upper side (7) and / or the lower side (8) of the PUR support body (6) in a material-integrated manner.

5. The shoe insole blank (1) according to claim 3, wherein: The covering material (25) has been fixed to the PUR support body (6) and / or the buffer body (10) in a material-integrated manner during the RIM foaming of the PUR support body (6).

6. The shoe insole blank (1) according to claim 1 or 2, wherein: The PUR support body (6) is made of PUR foams of various hardness and / or colors.

7. The shoe insole blank (1) according to claim 1 or 2, wherein the shoe insole blank (1) has two PUR support bodies (6), and the two PUR support bodies (6) are at least partially formed at different sides of the buffer body (10), so that the orthopedic foot bed is formed together by one or two PUR support bodies (6).

8. The shoe insole blank (1) according to claim 1 or 2, wherein: Before the buffer body (10) is foamed with PUR foam (5), an injection-molded part (19) with an orthopedic function is bonded to the buffer body (10) by means of an injection-molding process of the buffer body (10), the injection-molded part (19) being held by the buffer body (10) in a predetermined orthopedic position at least during the expansion of the RIM foam used for the purpose of producing the PUR support body (6).

9. The shoe insole blank (1) according to claim 8, wherein: The injection molded part (19) is arranged on the lower side (8) of the PUR support body (6), wherein the injection molded part (19) is visibly arranged on the lower side (18) of the insole blank (1), or the injection molded part (19) is covered by the buffer body (10).

10. The shoe insole blank (1) according to claim 1 or 2, wherein: The PUR support body (6) and / or the buffer body (10) can be ground and / or thermoformed in order to adapt the insole individually to the wearer.

11. The shoe insole blank (1) according to claim 1 or 2, wherein: The shoe insole blank (1) is subsequently covered with one or more covering materials (25) on the side of the footbed (3) and / or on the lower side (8) of the PUR support body (6).

12. A method for producing a shoe insole blank (1) of PUR foam plastic according to claim 1, the shoe insole blank (1) having a PUR support body (6) and at least one buffer body (10), the PUR support body (6) being formed in a RIM foaming process, the PUR support body (6) having a three-dimensional orthotic foot bed (3) on the upper side, and the at least one buffer body (10) being arranged on the upper side of the foot bed (3), the at least one buffer body (10) being made of a PU sheet (15) having no carrier layer and produced by solidification, extrusion or from a polyurethane dispersion mixture, the process comprising the following steps: a) inserting and fixing at least one buffer body (10) made of a PU sheet (15) into a first foaming mold half of a RIM foaming mold or into a second foaming mold half of the RIM foaming mold, wherein the first foaming mold half forms the upper side (7) of the PUR support body (6) facing the foot as a three-dimensional foot bed (3) by means of a first shaping surface, and the second foaming mold half forms the lower side (8) of the PUR support body (6) facing the shoe by means of a second shaping surface; b) applying an agent for producing the PUR foam (5) to the shaping surface of the second half of the foaming mold; c) closing the RIM foaming mold and simultaneously molding the buffer body (10) onto the PUR support body (6) by means of expanded PUR foam; d) After the curing time of the PUR foam (5) has expired, the RIM foaming mold is opened and the insole blank (1) is removed.

13. The method according to claim 12, wherein: The cushioning body (10) is inserted into the first foaming mold half of the RIM foaming mold while being bonded to a peelable protective film, so that the protective film faces the first shaping surface of the RIM foaming mold, wherein the protective film can remain on the cushioning body (10) after removing the insole blank (1), or the protective film can be removed from the cushioning body (10) without leaving any residue.

14. The method according to claim 12, wherein: The cushioning body (10) is inserted into the first foaming mold half of the RIM foaming mold while being bonded to a peelable protective film, so that the protective film faces the first shaping surface of the RIM foaming mold, the protective film protrudes beyond the shaping surface of the RIM foaming mold, and the protective film is fixed to the edge of the RIM foaming mold in the parting plane of the RIM foaming mold before or during the closing of the RIM foaming mold to ensure that the cushioning body (10) does not shift during RIM foaming, wherein the insole blank (1) is cut or punched into the form of a sole after being removed from the RIM foaming mold.

15. The method according to claim 13 or 14, wherein: The protective film is a sole covering material (25) for the insole blank (1), and the protective film can have a recessed portion, through which a portion of the buffer body (10) and / or the PUR support body (6) directly contacts the shaping surface of the RIM foaming mold.

16. The method according to claim 13 or 14, wherein: Before closing the RIM foaming mold, the orthopedic functional component is inserted into the first foaming mold half or the second foaming mold half in a non-slip manner, or before step a), the injection molded part is injection molded onto the buffer body (10), so that the buffer body (10) holds the injection molded part (19) in a predetermined orthopedic position at least during steps b) and c), and after step d), the injection molded part (19) is arranged on the lower side (8) of the PUR support body (6) or on the lower side (18) of the shoe insole blank (1).

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