Orthopedic innersole blank of PUR foam

Abstract

An orthopedic insole blank (1) of PUR foam has at least one buffer body (10) and a PUR support body (6), which supports a foot and is three-dimensionally molded in an RIM process. The PUR support (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. According to the invention, the at least one buffer body (10) is made of a prefabricated two-dimensional PU sheet (15) which is free of a carrier layer and which is 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) during the expansion of the RIM foam in a forming RIM foaming mould by foaming using the PUR foam (5).

Description

Technical Field

[0001] The invention relates to an orthopedic foam insole blank having a three-dimensional PUR support body molded in a RIM process, on the upper side of which at least one buffer body is arranged. In addition, an orthopedic foot bed is formed on the upper side of the PUR support body. The lower side of the PUR support body faces the sole. The invention also relates to a method for producing such an insole blank. Background Art

[0002] From the prior art, it is known that an orthopedic PUR foam insole blank is manufactured using a RIM process, and the insole blank has a PUR substrate or support body. The function of the substrate or support body is to support and guide the foot in an anatomical and orthopedic manner. For this purpose, the substrate or support body is made of a flexible but relatively strong PUR foam plastic, which, in addition to providing orthopedic support, must also provide biological buffering, for example when walking, so that sudden load changes are not violently transmitted to the skeleton of the foot. A buffer body is provided to further buffer the foot movement on the insole, and to adjust or balance the sole of the foot, or to reduce pressure peaks on particularly sensitive areas of the sole of the foot. This buffer body is softer than a PUR support body and can therefore better adapt to the sole of the foot. The better the interaction between the support body and the buffer body or the insole covering material, the better the orthopedic requirements can be met.

[0003] The PUR base or support is usually formed into the shape of the insole by foaming a polyol with an isocyanate in a RIM foaming mold. In this process, the two reactive starting components (polyol and isocyanate) are added to an open mold (usually a two-part mold), the cavity of which takes on the shape of the sole. Such RIM foaming molds are well known and are used to produce orthopedic insole blanks. However, PUR bases or supports produced by the RIM foaming process, especially if only one material hardness is used, do not have an optimal orthopedic effect or optimal wearing comfort on all areas of the sole of the foot. In addition, 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] Since orthopedic insole blanks have different requirements with regard to support and cushioning properties, especially in different areas of the sole, they cannot generally be manufactured with just one material / one material hardness. If, for example, different RIM foams are used, undefined, unpredictable support and cushioning properties occur in the transition area of ​​the foams, depending on how the foams flow towards each other during the foaming process. This and the formation of material fronts due to the foam generation cannot be produced completely reproducibly in a process-stable manner so that the exact sole area limitation can be maintained. For this reason, PUR support bodies are provided with cushioning bodies and other covering and facing materials or orthopedic components, so that the desired orthopedic support and cushioning properties are improved.

[0006] Therefore, individual sole areas of the support body (e.g. the forefoot area or the heel area) are usually designed with recesses in order to insert cushioning material, for example for cushioning and softening the heel bone in the vertical direction, while maintaining the stability of the heel and guiding it in the horizontal direction. Alternatively, reinforcements are inserted or connected in the longitudinal arch area in order to reinforce the orthopedic insole blank in the corresponding area with regard to the orthopedic function. At the same time, with the help of the covering material, an attempt is made to optimize the desired wearing comfort properties in these areas. The goal here is to achieve the two conflicting goals of rigidity and softness without creating edges or rigid parts that reduce the comfort of the wearer or reduce the orthopedic effect.

[0007] In order to achieve an orthopedic effect and at the same time achieve the desired wearing comfort, and in order to improve the appearance, the PUR support is usually provided with / covered with a cushioning body or a covering material, which has the desired properties in terms of cushioning, wearing comfort and appearance. However, the commonly used cushioning / covering materials have a negative impact on the orthopedic effect of the PUR support, and vice versa. This is due to the fact that the facing and covering materials conventionally used in the prior art usually have a textile carrier layer or an adhesion-promoting carrier layer in order to enable the cushioning and / or covering material to be bonded to the PUR foam plastic material of the support and / or to keep the cushioning and / or covering material stable and wear-resistant.

[0008] However, these carrier layers or adhesion promoting layers not only affect the inherent properties of the individual components of the insole in the contact area between the support and the cushioning material or the covering material, but also distort the force transmission of 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 rigidity in the longitudinal direction of the line (i.e., in the fabric plane), which reduces the cushioning at least in 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 exerted, because the fabric layer prevents the foot (e.g., 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 arch region can impair the firm connection between the covering material, the adhesive body and / or the orthopedic insert and the support body, since they can 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 covering materials is their wear resistance, i.e. a high level of wear resistance should be achieved while having good cushioning properties and comfort. These contrasting properties between wear resistance and good cushioning properties often lead to multi-layered coverings or composite materials, which often represent a compromise between the desired properties. The surface facing the foot is wear-resistant but the cushioning properties are insufficient, or vice versa. Therefore, high cushioning properties are usually coupled with low wear resistance.

[0011] Another challenge for the cushioning and covering materials is their ability to bond with the PUR material of the support body. Textile materials (e.g. fleece or similar materials) are penetrated by the not yet solidified PUR material during the foaming process and form a more or less rigid intermediate layer after solidification. At least on the upper side of the PUR support body or the lower side of the cushioning body, this impairs the elasticity and damping properties and the flexibility of the cushioning or covering material for the support body and for the boundary layer between the covering material and the PUR foam. In addition, the pressure load or force transmission transmitted by the foot to the insole is only transmitted indirectly and in a distorted manner, so that selective cushioning is almost impossible, for example in the forefoot area, especially in the metatarsophalangeal joint area. Summary of the invention

[0012] The object of the present invention is therefore to provide a foamed plastic insole blank, the support body of which is produced using a RIM foaming process and has at least one buffer body or covering material on its upper side and / or on the lower side facing the foot, which does not have a negative impact on the supporting properties of the support body and improves the buffering 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 are not carried out in separate process steps.

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

[0014] The insole blank of the orthopedic PUR foam plastic according to the present invention has a PUR support body, which is three-dimensionally formed using the 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, and an anatomically shaped foot bed with orthopedic function is formed on the upper side portion. At least one buffer body is arranged on the upper side portion and / or the 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 the reactive PUR foaming process. In the remainder of this specification of the present invention, the term "buffer body" should also be understood to refer to covering materials and facing 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 thickness of the material. Therefore, the terms "buffer body", "covering material" and "top material" should be understood as synonymous and interchangeable, depending on the requirements of the buffering, wearing comfort and / or decorative properties of the PU sheet.

[0015] In the course of the further description of the invention, the insole blank according to the invention is also referred to as insole in short, due to the fact that, for example, the insole blank removed from the RIM foaming mold can also be inserted directly into the shoe after cutting to the appropriate size and the missing foot bed is replaced there. In most cases, however, the insole blank according to the invention is intended to be further processed by an orthopedic specialist (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 invention apply to the insole blank and also to the shoe insert, these terms may also be used synonymously for the sake of convenience.

[0016] The material used for the cushioning body according to the invention (if its material thickness is relatively low, it can also be referred to as facing material or covering material) is an essentially two-dimensional PU sheet, which is produced from a polyurethane starting material without a carrier layer by a coagulation process, by an extrusion process or from a dispersed mixture. The PU sheet used according to the invention has no carrier layer, in particular no fabric used as a carrier. The PU surface material used according to the 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 invention is characterized by the fact that the length and width dimensions are significantly greater than the thickness of the material. It is not absolutely necessary that the thickness of the material is constant in width and / or length, even though this is a preferred embodiment in most cases. The term "surface material" is also intended to express the fact that the surface dimensions of the buffer 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, in order to meet the properties of the buffer 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, a strip, a continuous material or a roll material, and that the PU surface material is only cut into an appropriate length or cut into an appropriate size before being inserted into the RIM foaming mold, that is, it is specially prepared for insertion into the foaming mold.

[0019] In contrast to PUR foams with a PUR support, which are produced in a 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 solidification, 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 way can be foamed directly with the PUR foam produced in the RIM foaming mold and fixed in place, because the two polyurethane materials are bonded to each other during the curing of the PUR foam without forming a rigid or cured interface layer. Such an interface layer is formed when a carrier layer (especially a textile carrier layer) is arranged on the surface material, because the still soft PUR foam penetrates the carrier layer before the reaction-produced PUR foam hardens in the RIM foaming mold, thereby creating a PUR foam reinforced by the carrier layer in the interface layer between the support body and the cushioning body. In the interface area, both the support body and the cushioning body still have (greatly) reduced elastic properties, which can have a negative impact not only on the orthopedic effect of the insole, but also on the wearing comfort. For example, due to the cross-linking / rigidification of the interface, point loads on the support body can no longer be supported at specific points, but are distributed over a wider area, which leads to an overall harder, softer feel to the support or cushioning, although the hardness of the PUR foam used remains unchanged.

[0021] Even though urethane is not a monomer of polyurethane, when these two PU materials are connected, no rigid or hardened interface is formed, because both PU materials have urethane as a functional group. Therefore, the properties of the two PU materials are largely retained in the area of ​​the contact surface of the two sole bodies, so that a soft, especially stepless transition of the material properties of the support body to the material properties of the buffer body can occur in the thickness direction of the insole. This provides particularly comfortable wearing comfort without compressing the supporting properties of the PUR foam plastic of the support body or the buffering properties of the PU covering material (buffer body). In general, this means that without a rigid interface, forces can be continuously transmitted to the insole and buffered. As a result, the load transfer, support and buffering functions of the insole can be calculated and predicted more evenly and better, so that the insole blank according to the present invention and the insole manufactured therefrom can be adjusted more accurately and better to meet the needs of the wearer of the insole.

[0022] In addition, the orthopedic insole blank can be individually adapted to the foot or sole of the person wearing the insole. This is usually achieved by the fact that the material used for the support body and the buffer body, if not milled, can at least be ground. If the buffer body with a textile carrier layer according to the prior art is milled and / or ground by the orthopedic shoe manufacturer for individual fitting, the ground area will inevitably have a worn appearance. The unsightly appearance of such a ground insole is avoided by using the non-woven PU sheet according to the invention, since no grinding lines extend from the insole anymore. Therefore, the (individually) adapted and processed insole blank according to the invention also has a more attractive appearance than the conventional insole blanks known from the prior art.

[0023] According to the present invention, it is not mandatory that the covering material or the buffer body consists of a polyurethane (PU) sheet, but the inventors are not aware of any other suitable covering material or buffer 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 is also important to ensure that only materials are used that have been classified as harmless to health by the health authorities of the respective countries 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 on the basis of PU artificial leather as a preferred material. However, if PVC is approved for shoe insoles one day, the present invention can also be applied to PVC artificial leather with necessary modifications. If PVC is approved as a covering material for orthopedic functional shoe insoles in other countries outside 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 already obvious to a person skilled in the art, a PU sheet without a carrier layer can be made thinner than a covering material with a (fabric) carrier layer. This effect is particularly significant if a cushioning body is to be formed on a covering material that conforms to the foot, because the rigid carrier layer should be as far away from the sole as possible to ensure that the cushioning body conforms to the foot. According to the invention, such a rigid carrier layer is not required, which makes it possible to make the cushioning body thinner. This effect is further enhanced by the flexibility of the PUR support body, because it no longer forms a rigid counter-support, such as a hardening interface or an intermediate layer. For example, this is preferred for the insoles of diabetics, because the material hardening transition can be cushioned with a thinner cushioning body, thereby allowing the insole to be made thinner as a whole. However, for street, sports, leisure and / or work shoes, thinner insoles are also preferred, especially if the insoles of such shoes are not replaceable and the insoles are additionally inserted into the shoes. This can, for example, prevent the 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 will not be distorted by the rigid interface.

[0027] The buffer body or the covering material only partially or completely covers the upper side and / or the lower side of the insole blank. Since the two PU materials can be easily connected together, there is a great degree of design freedom, especially in the arrangement of the buffer area and the support area. Therefore, according to the invention, the buffer body can have the shape of the complete sole, while the support body is only formed in the orthopedic functional support area. The person skilled in the art will also recognize the possibility of a reverse embodiment, in which the buffer body is only formed in the area where the sole of the foot needs to be buffered.

[0028] This also allows embodiments in which a plurality of buffer bodies and covering materials are used, both of which are made of the PU sheet according to the invention, for example, the buffer body passes through a recess in the covering material, or the buffer body is fixed to the support body by means of the covering material. This can be achieved, for example, in a sandwich structure, in which the support body fixes the buffer body to the covering material and vice versa. This means that the buffer body can be completely covered by the covering material or only partially covered, whereby both the buffer body and the support body can be immersed and / or visible through the recess in the covering material.

[0029] According to the invention, the insole blank is produced using a RIM foaming process. According to the invention, a RIM foaming mold is used, which is usually made of two foaming mold halves. The first half of the foaming mold forms the upper side of the support body facing the foot, with a three-dimensional foot bed on the upper side. The second foaming mold half forms the lower side of the support body facing the shoe. Therefore, the shaping surfaces of both mold halves show a negative image of the upper side or the lower side of the support body. In RIM foaming, the reagents (polyol and isocyanate) for forming the PUR foam are introduced into the lower foaming mold half (usually referred to as the second foaming mold half) in liquid form through a mixing head. When the two reagents come into contact, they react exothermically to form a PUR foam plastic. In order to form the defined molded body, in this case the support body, the RIM foaming mold has a cavity in a closed state, which is formed by the first half of the foaming mold (usually the upper half of the foaming mold) by placing it on the second half of the foaming mold. 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 agents can expand in the cavity until they are used up. After the curing time has passed, 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 by means of a so-called mixing head. When the two reagents come into contact, they begin to chemically react with each other to form 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 introduction of the reagents. This is usually done in a guided straight and / or folding motion. The closed mold is then locked or maintained. If the PU sheet is so large that it extends beyond the shaping surface, the locking force or holding force can be used to eventually 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 plastic have been introduced into the lower half of the foaming mold before the foaming mold is closed, and can now expand in the cavity to form the PU foam plastic, the PU sheet in the closed foaming mold is now also foamed by the expanded PU foam plastic. This forms a material bond between the PU sheet and the PU foam plastic. 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 plastic being formed, and is 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 plastic has hardened and the foaming mold can be opened. The insole blank of the foam plastic 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 invention, there are various possibilities for inserting the PU sheet or the buffer body. One is to use a protective film that is bonded to the buffer body and can be peeled off, with which the buffer body / PU sheet is inserted into the first foaming mold half, wherein the protective film faces the excipient surface. The protective film is at least so lightly bonded to the inside of the first foaming mold half that the protective film 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 PU sheet attached can then be clamped in the parting plane formed between the two foaming mold halves and the buffer body is kept in its intended orthopedic functional position.

[0035] After the RIM foaming moulding 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 possibility is to cut the PU sheet so wide that it is clamped directly in the mold parting plane of the two foaming mold halves when the foaming mold is closed. This is particularly preferred if the PU sheet is relatively thin and thus negative influences on the parting plane can be avoided. At the same time, the PU sheet can seal the parting plane so that no PUR foam can escape from 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 that remains on the insole blank. For example, this is previously bonded to the PU sheet.

[0038] In another embodiment, in which a cushioning body made of a PU sheet is to be applied to a RIM support body according to the present invention, a covering material or a 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 foot bed, but can be arranged only in a partial area of ​​the insole of the finished product. In this embodiment, the covering material or the protective film is only used to position or fix the cushioning body or another orthopedic functional component in its intended orthopedic position. In this case, the cushioning body is therefore held in its predetermined orthopedic position by the covering material in the RIM foaming mold 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 orthopedic experts (such as pads, support wedges, heel wedges and similar orthopedic components) can also be fixed in predetermined positions in the insole of the finished product with the help of covering materials or PU sheets.

[0039] In another preferred embodiment of the invention, the injection molded part is injected onto the buffer body before the buffer body is inserted into the foaming mold. For this purpose, 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 orthopedic 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 orthopedic position in the RIM foaming mold by the buffer body (i.e., by the PU sheet).

[0040] Preferably, the injection molded part injected onto the buffer body made of the PU sheet is arranged on the lower side of the insole blank, because such injection molded parts are usually made of relatively hard materials, so that they can exert a good supporting effect on the foot. In order to ensure that the upper side of the insole blank according to the invention still exhibits soft and elastic buffering properties, the PUR support body is preferably arranged above the injection molded part, that is, on the upper side, so that the support body can be regarded as a kind of buffer body for the injection molded part.

[0041] According to the present invention, the injection molded part arranged on the buffer 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 to turn away from the shaping surface. If the injection molded part faces the cavity, the injection molded part is at least partially covered by the PU sheet in the RIM molded insole blank, because the buffer 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] The method for producing the insole blank according to the invention is described above with reference to the use of only a single PUR foam, as known to those 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 of 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 into the second foaming mold at different points through multiple mixing heads or a mixing head in rapid succession, and can then be expanded in parallel in the closed foaming mold. If no mechanical flow boundary is provided, the material front obtained is formed according to the reaction speed of the individual PUR foams produced. Therefore, it is difficult to form a clear, reproducible material front, especially when the PUR foams enter each other and mix in some areas. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0047] Figure 4 schematically shows 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, which is formed on the upper side 7 of a support body 6 made of PUR foam 5. The footbed is covered with a damping body 10, wherein a carrier layer 4 serves as a connection adhesion-promoting layer for holding the damping 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 insole blank 1 according to the invention is also shown in a schematic longitudinal section. The 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 a PUR foam 5. The support body 6 of the insole blank 1 according to the invention is also covered with a damping 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 damping body 10 can be omitted. Figure 1 The adhesion promoting layer 4 known from the prior art is shown, since the material of the cushioning body 10 is bonded to 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, whereby the 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 part of the description of the invention.

[0052] Figure 3The insole blank according to the invention is shown in a second embodiment, wherein 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 is 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 insole blank 1 schematically shown in Figure 1 also shows a support portion 19 arranged in the heel area 13. The 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 lower side 18 of the shoe facing the insole blank 1. According to the invention, the injection molded portion 19 is injected onto the PU sheet 15 of the cushioning body 10 so that it can be inserted and fixed in the RIM foaming mold together with the PU sheet 15 so that the injection molded portion 19 is 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 be clamped, for example, in the parting plane of the two foaming mold halves so that both the cushioning body 10 and the injection molded portion 19 do not slide during the expansion of the PUR foam in the RIM foaming mold and the injection molded portion 19 is firmly held in the desired predetermined orthopedic functional position.

[0053] Figure 4 To Figure 3 The embodiment variant of FIG. 1 shows a third embodiment of an insole blank 1 according to the invention having an internal injection-molded portion 19 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. 1 , the support body 6 is arranged on the upper side 17 of the insole blank 1 , and the support body 6 may 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 on 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 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. Therefore, according to Figure 4The exemplary embodiment of shows the injection-molded part 19 which is 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 orthopedic specialist.

[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 middle area 12 and the heel area 13 of the sole. The buffer body 10 is in direct contact with the sole of the wearer of the insole through these recesses 16. In this case, the buffer bodies 10 can be connected to each other under the additional covering material 25, or the buffer bodies 10 can be separate buffer bodies 10 that are separately connected to the support body 6. Separate buffer bodies 10 can be used to individually adapt the buffering and support requirements required for orthopedics in each individual area. For example, a softer buffer 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 buffer body 10 than the buffer for the big toe.

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

[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, an insole blank can be produced which exhibits one or more buffer 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 buffer bodies 10 or the PU sheet of the covering material 25 additionally applied to the upper side 17 and / or the lower side 18 of the insole blank 1 according to the invention can have a recess 16 through which the injection-molded part 19 and / or the PU sheet 15 of the one or more buffer bodies 10 are visible. A person skilled in the art will recognize a large number of possible combinations here, all of which are connected by the inventive concept of using a PU sheet 15 without a carrier layer as a buffer body 10. List of reference numerals 1 Orthopedic shoe insole blanks 3-foot bed 4 Carrier layer 5. PUR foam plastic 6 PUR support 7 Upper side of the support 8 Lower side of support body 9 Orthopedic functional parts (inserts) 10 Buffer 11 Forefoot area 12 midfoot area 13 Heel area 15 PU sheet 16 recess 17 Upper side of the insole blank 18 Lower side of the insole blank 19 Injection molded parts 25 Covering material 100 Insole for footwear according to the prior art

Claims

1. An orthopedic PUR foam insole blank (1), the insole blank (1) having 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 lower side portion (8) on the shoe side and an upper side portion (7) on the foot side, an anatomically shaped orthopedic foot bed (3) being formed on the upper side portion (7), wherein the at least one buffer body (10) is composed of a prefabricated two-dimensional PU sheet (15), the PU sheet having no 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 plastic by foaming with PUR foam plastic (5) in a material-integrated manner at the upper side portion (7) and / or at the lower side portion (8) of the PUR support body (6).

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 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 cutout (16), through which the buffer body (10) and / or the support body (6) are at least partially visible.

4. The shoe insole blank (1) according to any one of the preceding claims, wherein Two or more buffer bodies (10) are fixed to the top side (7) and / or the bottom side (8) of the PUR support body (6) in a materially integral manner.

5. The shoe insole blank (1) according to claim 3 or 4, wherein: The covering material (25) has been fixed to the polyurethane support body (6) and / or the buffer body (10) in a materially integral manner during the RIM foaming of the polyurethane support body (6).

6. The shoe insole blank (1) according to any one of the preceding claims, wherein The PUR support body (6) is made of PUR foams of various material hardness and / or colors.

7. The insole blank (1) according to any one of the preceding claims, wherein the insole blank (1) has two PUR support bodies (6), which are at least partially formed at different sides of the cushioning body (10), so that the orthopedic foot bed is formed by one or two support bodies (6) together.

8. The shoe insole blank (1) according to any one of the preceding claims, 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 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 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 any one of the preceding claims, wherein The PUR support body (6) and / or the damping body (10) can be ground and / or thermoformed in order to adapt the insole to the wearer individually.

11. The shoe insole blank (1) according to any one of the preceding claims, wherein The insole blank (1) is subsequently covered with one or more covering parts (25) on the side of the foot bed (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 orthopedic 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 (6) 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 (7) 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 11, 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 10, 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 any one of claims 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 support body (6) directly contacts the shaping surface of the RIM foaming mold.

16. The method according to any one of claims 12 to 15, 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) maintains 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 support body (6) or on the lower side (18) of the insole blank (1).

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