Soles for sports shoes

Abstract

The present invention relates to a sole, in particular a midsole, for a sports shoe. The sole comprises a first additively manufactured layer and a second additively manufactured layer. A bottom side of the second layer is arranged on a top side of the first layer in at least a first region. The sole is further configured such that, while the sole is subjected to a first loading intensity, a first contact surface of the top side of the first layer and a second contact surface of the bottom side of the second layer are arranged spaced apart from one another in the first region.

Description

1. Technical FieldThe present invention relates to soles, in particular midsoles for sports shoes and other types of shoes.2. Background ArtSoles of shoes typically fulfil a wide variety of functionalities. For example, soles can provide traction to the foot and protect the foot from sharp objects. An important functionality of soles and in particular midsoles is also to cushion shocks and cushion the foot. Various sole constructions and materials have been developed to specifically optimize soles in the light of their cushioning properties. Typical materials used for soles due to their good cushioning properties are for example foamed ethylene vinyl acetate (EVA) or expanded thermoplastic polyurethane (ePTFE).In addition to these materials that mostly completely fill the midsole, attempts have already been made to develop structures that consist of a lattice structure by means of additive manufacturing methods. Lattice structures known from the prior art can be composed, for example, of nodes with elongated elements arranged between the nodes, wherein intermediate spaces of the lattice structure can remain free of sole material. The damping strength of such lattice structures can be adjusted here on the basis of the density of the nodes or as a function of the length and number of the elongate elements.In this regard, for example, WO 2014 / 100462 discloses a midsole formed as a net-like structure having a plurality of elongated members that can provide surfaces with increased or decreased support, cushioning, and / or stability in various areas of the midsole.Document EP 3 155 917 B1 further discloses an additively manufactured sole comprising a lattice structure, wherein the lattice structure has a plurality of cell elements. The sole further comprises a heel element, which surrounds the heel three-dimensionally, and a base section, which connects the heel element and the lattice structure to one another.However, the known soles manufactured by additive manufacturing have several deficiencies with respect to the functional properties of the shoe soles. For example, in known soles, due to the lattice structure, no discrete and different amount of cushioning can be provided when the lattice structure is compressed. Furthermore, the freedom of movement of the sole is greatly limited due to the elongated elements firmly connecting the nodes, whereby the degree of cushioning is also only slightly adjustable.It can therefore be considered an object of the present invention to overcome or at least reduce at least some of the deficiencies encountered in known additively manufactured soles.3. SUMMARY OF THE INVENTIONThe above problems are solved by the subject matter of the independent claims of the present invention. Exemplary embodiments of the invention are defined in the dependent claims.The present invention provides a sole, in particular a midsole, for a sports shoe. The sole comprises a first additively manufactured layer and a second additively manufactured layer. An underside of the second layer is arranged in at least one first region on an upper side of the first layer. The sole is further configured such that, while the sole is subjected to a first stress intensity, a first contact surface of the upper side of the first layer and a second contact surface of the lower side of the second layer are arranged spaced apart from each other in the first region.The sole may thus comprise at least the first and the second contact surface which are not in contact under certain load intensities exerted on the sole, namely under the first load intensity. The term "contact surface" as understood according to the present invention means a surface within a first additively manufactured layer which is adapted for contact with a contact surface of a further layer, in particular likewise additively manufactured. Due to the spaced apart arrangement of the first and second contact surfaces, the sole can provide a higher freedom of movement compared to known additively manufactured soles in which the sole does not contain spaced apart contact surfaces. This is due, at least in part, to the lack of contact of the spaced contact surfaces allowing relative movement between the adjacent layers.The first layer may further include a first grating structure. Additionally or alternatively, the second layer may have a second grating structure. A lattice structure can be composed of nodes which are connected by connecting elements. A lattice structure with a higher number of nodes and / or at connecting elements between the nodes provides a lower compressibility than an otherwise identical lattice structure, which however has fewer nodes and / or fewer connecting elements. Here, the term "compressibility" describes a damping property of a body and indicates a relationship between a change in the volume of the body with respect to a change in the pressure applied to the body. A high compressibility of a sole can thus be associated with a soft sole and a low compressibility with a hard sole. Since, while the sole is exposed to the first load intensity, the first and second contact surfaces are spaced apart, no force transmission can take place between the two layers via these contact surfaces. Therefore, the structures of the adjacent layers forming the contact surfaces do not contribute substantially, for example less than 10%, to the compressibility of the sole during the first load intensity.The first and second layers may comprise a different grating structure. Compressibility of the second lattice structure may be less than compressibility of the first lattice structure. By being able to provide the sole with different compressibilitys of the first and second layers, the respective compressibility can be optimized specifically for a provided load range. For example, in the first load range, the compressibility of the sole can be provided substantially by the first lattice structure. Since this is softer as a result of its greater compressibility in comparison with the second lattice structure, the first lattice structure is initially substantially compressed when a force is exerted on the sole in the first load region. "Substantially" in this case means that a compression of the sole in the first load region is based at least to 80% on a compression of the first lattice structure. Furthermore, in the second load range, the compressibility of the sole can be provided substantially by the second lattice structure. In general, the present invention may provide a sole wherein during a first stress intensity, a first portion of the sole having high compressibility substantially provides compressibility of the sole. Other regions of the sole which have a lower compressibility contribute only insignificantly to the compressibility of the sole at the same load intensity. "Essentially" here means that a compression of the sole in the first load region is based at least to 80% on a compression of the first region, wherein "insignificantly" is accordingly to be understood as being at most 20%.The first load intensity may correspond to a force in the range of zero to 20 percent of a maximum force for which the sole is configured. The term "maximum force" refers here to an amount of force at which the compressibility of the sole is determined substantially by a compressibility of the material used for the production of the sole and no longer by the structure of the sole. For example, in the case of soles having a lattice structure, the lattice structure can be loaded from a load intensity of more than 80% of the maximum force in such a way that adjacent connecting elements and / or nodes begin to touch. This can be noticeable for a wearer of a shoe with this sole by an abrupt drop in compressibility.The sole may be configured such that, while the sole is subjected to a second stress intensity that is greater than the first stress intensity, the first contact surface of the top side of the first layer and the second contact surface of the bottom side of the second layer are at least partially in contact with each other in the first region. The second load intensity may correspond to a force in the range of greater than 20 percent, in particular up to 50 percent, of a maximum force for which the sole is configured. If the magnitude of the compressive force on the sole is accordingly increased beyond the first load intensity, the sole can be configured such that the first and second contact surfaces now touch one another. This can be assumed to be equivalent to an effective increase of the nodes of the lattice structure, as a result of which an abrupt change, in particular a reduction, of the compressibility of the sole can result. The sole can accordingly provide a wearer with at least two different compressibility regions.The sole may be configured such that when the first contact surface of the upper side of the first layer and the second contact surface of the lower side of the second layer are at least partially in contact with each other in the first region, the sole remains compressible. This means that the first and second contact surfaces are at least partially in contact with one another from the above-described case of the force exerted on the sole of more than 80% of the maximum force at which elements not provided for the contact, such as nodes and / or connecting elements of a lattice structure, touch.The sole may be configured such that when the sole is subjected to the first stress intensity, the sole has a greater compressibility than when the sole is subjected to the second stress intensity. The sole can accordingly have at least two different compressibility regions, wherein an abrupt drop in compressibility occurs at the transition from the first stress intensity to the second stress intensity, i.e. when the first and the second contact surface begin to contact. This drop may be noticeable to a wearer of a shoe having a sole according to the present invention by an abrupt change in cushioning property. For example, the first stress intensity may be applied to a sole during boarding a shoe. This allows the shoe to feel soft for a wearer, which provides high comfort during boarding for the wearer. The second load intensity can also be exerted on the shoe during walking or during slow running. As already explained, the compressibility can change abruptly in this case, which can provide the wearer of the shoe with a higher stability during walking or during slow running compared to the first load intensity. Thus, the sole may be adapted to provide a wearer with a compressibility and / or stability optimized for the situation in various situations, for example when getting into the shoe and walking.The sole may further comprise a third additively manufactured layer. By adding a third layer, the sole can be provided with further advantageous properties.An underside of the third layer can be arranged in at least one second region on an upper side of the second layer. By virtue of the fact that the third layer can be arranged at least partially over the second layer, compressibility of the sole can be increased.The sole may be configured such that, while the sole is subjected to the first or the second stress intensity, a third contact surface of the upper side of the second layer and a fourth contact surface of the lower side of the third layer are arranged spaced apart from each other in the second region. Due to the spaced arrangement of the third and fourth contact surfaces, the sole can provide a higher freedom of movement compared to known additively manufactured soles in which the sole does not contain spaced contact surfaces.The sole may be configured such that, while the sole is subjected to a third stress intensity that is greater than the second stress intensity, the third contact surface of the upper side of the second layer and the fourth contact surface of the lower side of the third layer are at least partially in contact with each other in the second region. If the magnitude of the compressive force on the sole is accordingly increased beyond the second load intensity, the sole can be configured such that the third and the fourth contact surfaces now also touch in addition to the first and second contact surfaces already in contact. This can be equalized with a further effective increase of the nodes of the lattice structure, as a result of which a second abrupt change, in particular a second reduction, of the compressibility of the sole can result. The sole can accordingly provide a wearer with at least three different compressibility regions.The third load intensity may correspond to a force in the range of greater than 50 percent, in particular up to 80 percent, of a maximum force for which the sole is configured. The sole may be configured such that, while the sole is exposed to the third stress intensity, the first contact surface of the upper side of the first layer and the second contact surface of the lower side of the second layer are at least partially in contact with each other in the first region.The sole may be configured such that when the sole is subjected to the first or second stress intensity, the sole has a greater compressibility than when the sole is subjected to the third stress intensity. In other words, the sole can be harder in the region of the third stress intensity than in the region of the first or the second stress intensity. Similar to the transition from the first to the second stress intensity, the transition from the second to the third stress intensity, i.e. when the second and the third contact surfaces begin to contact, may also occur as a further abrupt drop in compressibility. This second drop may be noticeable to a wearer of a shoe having a sole according to the present invention by a second abrupt change in cushioning property. For example, the third stress intensity may be applied to a sole during running, jogging, running, or similar intense stresses in other sports. As a result, the shoe can provide a wearer with a further increased stability during intensive training units than during the second load intensity. Thus, the sole can be adapted to provide a wearer with a gradually adapted compressibility and / or stability optimized for the situation in all situations, from getting into the shoe via light walking training up to intensive loads.The third layer may have a third grating structure.The first, second and third layers may comprise a different grating structure. For example, compressibility of the lattice structure can decrease from the first lattice structure via the second lattice structure to the third lattice structure. The decreasing compressibility of the different lattice structures can ensure that these successively contribute to the overall compressibility of the sole. In other words, this provides for the grid structures to be activated successively, as a result of which these successively contribute to the cushioning provided by the sole.The lattice structure of the first, the second and / or the third layer may have a resilient property which may cause the lattice structure to bring the lattice structure back to its unloaded shape or its original shape before a load in the absence of or too low a load intensity. The springback property can advantageously contribute to the recovery of the energy introduced into the sole.A maximum force for which the sole is configured may depend on a size of a shoe for which the sole is provided. If one proceeds from an increasing body weight with an increasing shoe size, larger shoes must be designed for a larger maximum force. For example, the maximum force for a shoe size of UK 8.5 may be 2000 Newtons and / or for a shoe size of UK 5.5 1625 Newtons.The top side of the first layer may have a plurality of first contact surfaces and the bottom side of the second layer may have a plurality of second contact surfaces, wherein superposed first and second contact surfaces may be configured such that, while the sole is subjected to the first stress intensity, the superposed first and second contact surfaces are spaced apart. The top side of the second layer may comprise a plurality of third contact surfaces and the bottom side of the third layer may comprise a plurality of fourth contact surfaces, wherein superposed third and fourth contact surfaces may be arranged such that, while the sole is subjected to the first or second stress intensity, the superposed third and fourth contact surfaces are spaced apart.The first and second contact surfaces of the first and second layers arranged one above the other may be configured such that, while the sole is subjected to the second stress intensity, the first and second contact surfaces arranged one above the other are at least partially in contact with each other. The third and fourth contact surfaces arranged one above the other may be configured such that, while the sole is subjected to the third stress intensity, the third and fourth contact surfaces arranged one above the other are at least partially in contact with each other. The first and second contact surfaces arranged one above the other may be further configured such that, while the sole is subjected to the third stress intensity, the first and second contact surfaces arranged one above the other are at least partially in contact with each other.By providing the first and second contact surfaces and / or the third and fourth contact surfaces by a plurality of contact surfaces, compressibility can be adjusted uniformly over the entire sole, on the one hand. On the other hand, however, this also allows specific regions of the sole, such as, for example, a heel region, midfoot region, forefoot region, football region, toe region, etc., to be produced with different compressibility. This makes it possible to adapt the cushioning properties of a sole specifically to the requirements of a wearer, a sport type or generally a stress type.At least a first portion of the first and second contact surfaces may have a substantially flat shape. Additionally or alternatively, at least a seventh part of the third and fourth contact surfaces may have a substantially flat shape. A flat shape can provide high flexibility of damping characteristics under different load conditions. A flat shape of the contact surfaces can also allow an intended compressibility even if the contact surfaces meet with an offset. For example, it may be sufficient if the two contact surfaces touch each other at least with 50% of their contact surface. A flat shape of the contact surfaces can be particularly advantageous for more rigid materials, for example materials with a Shore hardness in the range from 80 to 98 Shore A.At least a second portion of the first and second contact pads may have a shape configured to prevent horizontal movement between the first and second layers in at least one direction when the at least second portion of the first and second contact pads is in contact. Additionally or alternatively, at least an eighth portion of the third and fourth contact pads may have a shape configured to prevent horizontal movement between the second and third layers in at least one direction when the at least eighth portion of the third and fourth contact pads is in contact. Similar to a flat contact surface, the contact surface preventing a horizontal movement in at least one direction can also enable an provided compressibility even if the contact surfaces meet with an offset. Furthermore, lateral movements can be directed in a predetermined direction due to the shape of the contact surfaces. As a result, an energy transfer between two layers of the sole along the at least one direction of movement to be prevented can be provided. Furthermore, injuries due to the reduced energy transmission in a direction in which a horizontal movement is not prevented can be reduced, since in this case the energy transmission between the layers is reduced, in particular is determined only by the friction of the contact surfaces.At least a third portion of the first and second contact surfaces may have a shape configured to allow rotational movement between the first and second layers when the at least third portion of the first and second contact surfaces are in contact. Additionally or alternatively, at least a ninth portion of the third and fourth contact pads may have a shape configured to allow rotational movement between the second and third layers when the at least ninth portion of the third and fourth contact pads is in contact. In addition to the advantages of the flat contact surfaces and the unidirectional movement preventing contact surfaces, by allowing rotational movements between two layers of the sole, the advantageous properties of gradually changing compressibility can also be provided for twist movements and / or twists within the sole. The mold can furthermore be configured to prevent a horizontal movement between the first and the second layer and / or between the second and the third layer in at least one direction in addition to the permitted rotational movement. As a result, for example, a centring effect can be achieved which enables alignment of the two adjacent layers of the sole. For example, the shape of opposing contact surfaces can be embodied similar to the functioning of a ball joint with ball and socket. In this case, the shape of the contact surfaces can deviate from a spherical shape and a socket shape, but the functioning of the ball joint is retained.At least a fourth portion of the first and second contact pads may have a shape configured to prevent horizontal movement and rotational movement between the first and second layers when the at least fourth portion of the first and second contact pads is in contact. Additionally or alternatively, at least a tenth portion of the third and fourth contact pads may have a shape configured to prevent horizontal movement and rotational movement between the second and third layers when the at least tenth portion of the third and fourth contact pads is in contact. As long as the stress intensity is not sufficient to bring the at least fourth part of the first and the second contact surfaces and / or the at least tenth part of the third and the fourth contact surfaces into contact, the first layer can rotate relative to the second layer or the second layer relative to the third layer and be displaced horizontally, i.e. along the layers. However, if the load intensity is increased sufficiently to cancel the respective spaced apart arrangement of the contact surfaces and bring them into contact, both the rotational movement and the horizontal movement are prevented. This makes it possible to provide a wearer with a particular feeling in wearing a shoe having a sole according to the present invention. For example, an advantageous forward effect can be produced during running. In this case, when sufficient stress intensity occurs in order to bring the at least fourth part of the first and the second contact surfaces and / or the at least tenth part of the third and the fourth contact surfaces into contact, a relative movement of the respective layers is prevented. In this case, the shoe is advantageously driven forward in the running direction at each occurrence, instead of returning only the energy which deformed the sole by the occurrence.At least a fifth part of the first and second contact surfaces may have a shape configured to at least partially maintain a compressed state of the first and second layers by a snap-in function. Additionally or alternatively, at least an eleventh part of the third and fourth contact surfaces may have a shape configured to at least partially maintain a compressed state of the second and third layers by means of a snap-in function. The snap-in function may provide selectively adjustable compressibility. If, for example, a low compressibility is required, the latching function can be activated.The mold may be further configured to release the snap-in function based on a re-compression movement, a shear force between the first and second layers and / or the second and third layers, a temperature of the sole, or a combination thereof. If a carrier previously activated the snap-in function, however, it would be advantageous to return back to the higher compressibility, the snap-in function can be released again.At least a sixth portion of the first and second contact pads may have a wave shape, wherein the waveforms of the first and second contact pads may be configured such that a wave crest of the first layer is configured to engage a wave trough of the second layer while the sole is exposed to the second stress intensity. Additionally or alternatively, the undulations of the first and second contact surfaces may be configured such that a wave valley of the first layer is configured to engage a wave crest of the second layer while the sole is exposed to the second stress intensity. Additionally or alternatively, at least a twelfth part of the third and the fourth contact surfaces may have a waveform, wherein the two waveforms may be configured such that a wave crest of the second layer is configured to engage a wave trough of the third layer while the sole is subjected to the third stress intensity. Additionally or alternatively, the two waveforms may be configured such that a wave trough of the second layer is configured to engage a wave crest of the third layer while the sole is exposed to the third stress intensity. The waveform may provide for smooth contacting of the first and second and / or the second and third layers. This can produce a smooth change between the compressibility ranges adjustable depending on the stress intensity, whereby a natural feeling of walking can be provided to a wearer.The sole may be configured such that the respective wave valleys and wave valleys of the first layer may engage different wave valleys and wave valleys of the second layer depending on a horizontal force applied to the first and / or second layer. Additionally or alternatively, the sole can be further configured such that the respective wave valleys and wave valleys of the second layer can engage different wave valleys and wave valleys of the third layer depending on a horizontal force applied to the second and / or third layer. As a result, a horizontal movement along a wave trough or wave crest between the first and second layer and / or the second and third layer can be provided, which enables the abovementioned advantages with respect to the horizontal movement. Further, a rotational movement may be provided between the first and second layers and / or the second and third layers, which enables the above mentioned advantages with respect to the rotational movement.At least one layer, two layers or three layers of the plurality of the first, second and third layers can have been produced by means of a method from: powder bed-based methods, in particular selective laser sintering (selective laser sintering), high-speed sintering (high-speed sintering), multi-jet fusion methods (multi-jet fusion); material extrusion methods, in particular fused filament fabrication methods (fused filament fabrication), melt lamination methods (fused deposition modeling); VAT polymerization methods, in particular stereolithography methods (SLA), digital light processing methods (digital light processing), digital light synthesis (digital light synthesis); or material jetting methods, in particular polyjet methods (polyjet modeling or multijet modeling).The sole may comprise at least one of the following materials: thermoplastic elastomers (TPE), thermoplastic polyurethanes (TPU), polypropylene (PP), polyamide 12 (PA 12), thermoplastic polyamide elastomers (TPA), thermoplastic polyester elastomers (TPC), which are particularly advantageously suitable for the powder bed-based method; acrylonitrile butadiene styrene copolymer (ABS), polylactide (PLA), polyethylene terephthalate glycol (PETG), polyamide 12 (PA 12), thermoplastic polyurethanes (TPU), polyvinyl acetate (PVA), high impact polystyrene (HIPS), which are particularly advantageously suitable for the material extrusion method; Elastomeric polyurethane (EPU), photopolymers in general, which are suitable in particular for the VAT polymerization process; acrylic polymers, which are suitable in particular for the material jetting process.4. Brief Description of the FiguresAspects of the present invention will be described in more detail below with reference to the accompanying figures. These figures show: FIG. 1 shows a schematic illustration of an embodiment of a sole having three layers of different lattice structures; FIGS. 2A-2C show a schematic representation of an embodiment of a sole with two layers of identical lattice structures during different stress intensities; FIGS. 3A-3L show a schematic representation of different contact surfaces of adjacent additively manufactured layers; and FIG. 4 is a graph of a compression curve of an embodiment of a sole as a function of the stress intensity exerted on the sole.5. DETAILED DESCRIPTION OF SOME EXEMPLARY EMBODIMENTSHereinafter, exemplary embodiments of the present invention will be described in detail with reference to a sole. While certain combinations of features will be described below with reference to the exemplary embodiments of the present invention, it is to be understood that the disclosure is not limited to such embodiments. In particular, not all features need be present to implement the invention, and the embodiments may be modified by combining certain features of one embodiment with one or more features of another embodiment.FIG. 1 illustrates an embodiment of a portion of a sole 100 according to the present invention. The sole 100 may be part of a midsole. The sole 100 comprises three additively manufactured layers, namely a first layer 110, a second layer 120 and a third layer 130. Each of the layers 110, 120, 130 is constructed from a different grating structure, wherein the three layers are arranged one above the other. The state of the sole 100 shown in FIG. 1 is present when the sole 100 is subjected to a first load intensity in the direction of the arrow 150. In this state, a first contact surface 140 of the first layer 110 is spaced apart from a second contact surface 141 of the second layer 120. At the same time, a third contact surface 142 of the second layer 120 is also present at a distance from a fourth contact surface 143 of the third layer 130. The contact areas 140, 141, 142 and 143 are here selected by way of example from the multiplicity of contact areas of the individual layers shown in FIG. 1, analogous applying to the contact areas of the same layer which are not explicitly mentioned.The first contact surface 140 has a socket shape that is arranged at nodes from which a plurality of connecting elements to adjacent nodes emerge. The second contact surface 141 has a spherical shape whose size is configured to fit into the socket shape of the contact surface 140. If the stress intensity is now increased up to the second stress intensity, the lattice structure of the first layer 110 is first deformed and compressed, while the second layer 120 approaches the first layer 110. In comparison to the compression of the first layer 110, the second layer 120 is compressed only insignificantly, i.e. less than 20%, preferably less than 10%, of the original extent of the second layer 120. This is because the compressibility of the lattice structure of the first layer 110 is greater than the compressibility of the lattice structure of the second layer 120. Once the second stress intensity is reached, the first contact surface 140 comes into contact with the second contact surface 141, while the third and fourth contact surfaces 142 and 143 remain spaced apart. The spherical shape of the second contact surface 141 is accordingly in the socket shape of the first contact surface 140. This prevents a horizontal movement, i.e. a displacement of the first and the second layer 110, 120 relative to one another. However, the spherical shape of the second contact surface 141 may freely rotatably move in the socket shape of the first contact surface 140, thereby allowing twist movements and twists between the first and second layers 110, 120. Both the first layer 110 and the second layer 120 are composed of a plurality of first and second contact areas 140 and 141.This also applies to the opposite side of the second layer 120 and to the third layer 130, which likewise consist of a plurality of third and fourth contact areas 142 and 143 together. The fourth contact surface 143 has a waveform which is best seen in FIG. 1 on the basis of the top side of the symmetrically constructed grating structure of the third layer 130. This waveform of the plurality of fourth contact surfaces 143 is adapted to be plunged into a depression of the third contact surface 142. In contrast to the first contact surface 140, however, the depression is not within a node of the lattice structure, but rather the nodes of the second layer 120 serve as a boundary for the depression. If the stress intensity is now increased up to the third stress intensity, the lattice structure of the second layer 120 first begins to deform and compress in addition to the already deformed lattice structure of the first layer 110. At the same time, the third layer 130 approaches the second layer 120. In comparison to the compression of the second layer 120, the third layer 130 is compressed only insignificantly, i.e. again less than 20%, preferably less than 10%, of the original extent of the third layer 130. This is because the compressibility of the lattice structure of the second layer 120 is greater than the compressibility of the lattice structure of the third layer 130. Once the third stress intensity is reached, the third contact surface 120 comes into contact with the fourth contact surface 143, while the first 140 and second 141 contact surfaces are still in contact. The wave shape of the fourth contact surface 143 is accordingly located in the depressions of the third contact surface 142. This prevents both a horizontal movement, i.e. a displacement of the second and third layers 120, 130 relative to one another, and a rotation between these two layers 120, 130.If the stress intensity is increased further after the third 142 and fourth 143 contact surfaces begin to contact one another, the lattice structure of the third layer 130 first begins to deform and compress in addition to the already deformed lattice structure of the first 110 and second 120 layers. A further increase in the direction of a maximum force for which the sole is configured ensures that first the nodes of the first layer 110, then those of the second layer 120 and finally also those of the third layer 130 start to touch. This behavior can occur, for example, at an intensity of more than 80% of the maximum force exerted on the sole. As a result, the compressibility drops abruptly, as a result of which the overall compressibility of the sole ultimately arises only via the material composition of the lattice structure and no longer via the lattice structure itself.It should be noted that FIG. 1 shows only a portion of the sole 100. In order to arrange the three layers 110, 120, and 130 spaced apart from one another as shown in FIG. 1, the sole 100 additionally comprises connecting elements which connect the first layer 110 to the second layer 120 and the second layer 120 to the third layer 130. These connecting elements are not shown in FIG. 1.Overall, the sole 100 according to the present invention provides a wearer with a nonlinear cushioning characteristic in which compressibility of the sole is abruptly reduced at least at the transition from the first to the second and at the transition from the second to the third load intensity. "Nonlinear" means here that the sole, when exposed to twice a force, for example, does not compress twice as much. The sudden change in compressibility is based on the contacting of two lattice structures which have been previously spaced apart and which increases a part of the lattice structure which is active / activated for damping the sole. A subsequent reduction of the stress intensity can furthermore lead to a detachment of the lattice structures of the two adjacent layers. Thus, the cushioning behavior of a sole according to the present invention is switchable repeatedly.FIGS. 2A to 2C illustrate an embodiment of a section of a sole 200 according to the present invention, wherein a stress intensity applied to the sole 200 increases from FIG. 2A, via FIG. 2B, up to FIG. 2C. The sole 200 may be part of a midsole. The sole 200 is composed of two layers produced additively, namely a first layer 210 and a second layer 220. Both layers 210 and 220 are constructed from an identical grating structure and are arranged one above the other.In FIG. 2A, a first stress intensity is applied to the sole 200. The first stress intensity is low enough, whereby the first 240 and second 241 contact surfaces of the lattice structures of the first 210 and second 220 layers do not touch each other. The first load intensity can result, for example, when a shoe is put on. In FIG. 2B, a second stress intensity is now applied to the sole 200. At the second stress intensity, which is greater than the first stress intensity, the first 240 and second 241 contact surfaces of the lattice structures of the first 210 and second 220 layers are in contact. As a result, the compressibility of the sole 200 is suddenly reduced. If the stress intensity is now increased further, the lattice structures of both layers 210, 220 begin to deform, which is shown in FIG. 2C on the basis of the smaller vertical extent. Since in this exemplary embodiment the grating structures of the first 210 and second 220 layers are of identical construction, an identical degree of deformation is also present in both layers.FIG. 3A illustrates an embodiment of a portion of a sole 300 according to the present invention. The sole 300 may be part of a midsole. The sole 300 is composed of three layers produced additively, namely a first layer 310, a second layer 320 and a third layer 330. Each of the layers 310, 320, 330 is constructed from a different grating structure, which is merely indicated in FIG. 3A. The three layers 310, 320, 330 are furthermore arranged one above the other. The state of the sole 300 shown in FIG. 3A is present when the sole 300 is subjected to a first stress intensity. In this state, a first contact surface 340 of the first layer 310 is spaced apart from a second contact surface 341 of the second layer 320. At the same time, a third contact surface 242 of the second layer 320 is also present at a distance from a fourth contact surface 343 of the third layer 330. FIG. 3A further includes connecting elements 360 located at the left and right edges of the cutout of the sole 300. These connecting elements 360 may be distributed over the entire sole 300 and connect the individual additively manufactured layers 310, 320, 330 to one another independently of the applied stress intensity. Connecting elements 360 can be understood as a frame structure for the individual layers 310, 320, 330. In another embodiment (not shown), the connectors 360 may connect only two layers together, respectively. In other words, the locations where the first layer is connected to the second layer need not be present at the same location where the second layer is connected to the third layer.The first 340, second 341, third 342, and fourth 343 contact surfaces of the sole 300 have a flat shape. As a result, sole 300 is configured, even when adjacent layers are displaced horizontally with respect to one another, not to lose the intended mode of operation as long as at least 50% of the surfaces can come into contact.Figures 3B-3L illustrate further embodiments of adjacent contact pads in accordance with the present invention. The contact surfaces can be used in an embodiment with two, three or more layers produced additively. Furthermore, the subsequent contact surfaces may be present between the first and the second layer and / or between the second and the third layer of a sole according to the present invention. It is also possible to combine different contact surfaces in different regions of two adjacent layers.FIG. 3B shows an embodiment 301 of two contact surfaces 340, 341 configured to allow a horizontal movement between the adjacent layers, which they are part of, in a direction along the arrow 350, after being brought into contact based on a sufficiently high stress intensity. The contact surfaces 340 and 341 are further configured to prevent horizontal movements that do not run along the direction of the arrow 350, as well as rotational movements between the two layers that they are part of. Thus, for example, an in-plane force between the two layers, which is perpendicular to the direction of arrow 350, may be transmitted from the lower layer to the upper layer. This may be advantageous in order to enable particularly effective propulsion during rapid running. At the same time, however, the embodiment 301 also makes it possible to prevent or at least substantially reduce a force transmission between the two layers in the direction of the arrow 350, in that the contact surface 341 can slide along the contact surface 340. This can in turn be advantageous in order to prevent injuries that could arise due to an unwanted force effect.FIG. 3C shows an embodiment 302 of two contact pads 340, 341 configured to allow rotational movement between the adjacent layers that they are part of after being brought into contact based on a sufficiently high stress intensity. The contact surface 340 here has the shape of a ball which can be arranged in the joint socket of the contact surface 341. This can be advantageous in order to achieve a special force transmission between adjacent layers during twist movements and / or twistings within the sole. In order to ensure that the spherical shape of the contact surface 340 can enter the socket shape of the contact surface 341 even in the case of additionally acting horizontal relative forces between the layers, additional guides can be provided (not shown). For example, the socket shape of the contact surface 341 could extend beyond the spherical shape of the contact surface 340 in the unloaded state.FIG. 3D shows an embodiment 303 of two contact surfaces 340, 341 which are configured to engage one another by means of the hook shape shown after they have been brought into contact based on a sufficiently high stress intensity. This can ensure that the two layers, the part of which is the contact surfaces 340 and 341, remain connected even when the stress intensity is reduced. Consequently, by means of embodiment 303, below the stress intensity which brings the two contact surfaces into contact, a sole with high compressibility or soft damping can first be provided. After a single activation, i.e. when the two contact surfaces 340, 341 have been snapped in, the sole can be provided with a lower compressibility. For example, a wearer of a shoe with a sole according to the present invention can already wear the provided training shoes on the way for training, which still have a soft cushioning with high wear comfort. In the training itself, the same pair of shoes can then be converted into shoes with lower compressibility and thus higher stability by means of the activation of the latching function.FIG. 3E shows an embodiment 304 of two contact pads 340, 341 each having a waveform. In this case, the wave crests of the contact surface 340 lie opposite the wave troughs of the contact surface 341, as a result of which both contact surfaces 340, 341 are configured to engage one another. The waveform allows the contact pads 340, 341 to accommodate a present horizontal offset, and thus non-ideal orientation, of the peaks from the valleys of both layers that they are part of after approaching based on a sufficiently large stress intensity. In this case, the wave crest of the one contact surface can slide smoothly as far as into the wave trough along the wave crest of the other contact surface. This allows for a smooth transition between the compressibility regions, which corresponds to a more natural damping characteristic. In addition, embodiment 304 may allow horizontal movement in a direction (perpendicular to the plane of the drawing in FIG. 3E ), thereby providing the advantages already discussed in this regard in connection with FIG. 3B.FIG. 3F shows a top view of an embodiment 305. Embodiment 305 comprises two contact surfaces 340, 341 configured to allow a horizontal movement (perpendicular to the plane of the drawing) between the adjacent layers, which they are part of, after being brought into contact based on a sufficiently high stress intensity. For exemplary embodiment 305, the one already explained with respect to exemplary embodiment 301 is equally valid, with the difference that the contact surfaces 340, 341 have a pointed shape. This may be advantageous in order to achieve accurate alignment of the two adjacent layers.FIG. 3G shows an embodiment 306 of two contact surfaces 340, 341 configured to, after being brought into contact based on a sufficiently high stress intensity, prevent both a rotational movement and a horizontal movement between the adjacent layers that they are part of. The contact surface 340 has a rectangular shape with protrusions 340 aon the side facing the contact surface 341. The contact surface 341 has a shape further expanded as compared with the size of the contact surface 340, and is provided with a plurality of recesses 341 a. The recesses 341 aare configured to receive the protrusions 340 awhen the contact surfaces 340 and 341 are brought into contact. The penetration of the elevations 340 ainto the depressions 341 aresults in preventing any relative movements between the two contact surfaces 340, 341 and thus also between the two layers, the parts of which are the contact surfaces 340, 341. This prevention of relative movements of the two layers makes it possible to provide a wearer with a particular sensation in wearing a shoe having a sole according to this embodiment. For example, an advantageous forward effect can be produced during running. Since any relative movement of the two layers is prevented by an occurrence of sufficient stress intensity to bring the two contact surfaces 340, 341 into contact, the shoe is advantageously driven forward in the running direction, instead of returning only the energy which deformed the sole by the occurrence. As soon as the foot leaves the ground again and as a result the stress intensity is no longer sufficient to keep both contact surfaces 340, 341 in contact, the two layers separate from one another. At the next occurrence, depending on a relative transverse force acting on the two layers, the elevations 340 acan then penetrate again into other or the same depressions 341 a.FIG. 3H shows an embodiment 307 of two contact surfaces 340, 341. The contact surface 340 here has a shape of a cylinder configured to be clipped by the contact surface 341. For this purpose, the contact surface 341 has a bent middle part 341 b, which is connected at both ends to a respective clamping arm 341 a. Now, when both the contact surfaces are brought into contact based on a sufficiently large stress intensity, the cylinder of the contact surface 340 presses the bent middle part 341 b. The bent middle part 341 bis thereby first straightened and subsequently bent into a bend oriented opposite to the starting state. This change in the direction of curvature of the bent middle part 341 bsecures that the two clamping arms 341 aare brought in the direction of the contact surface 340 and finally engage around the cylinder of the contact surface 340. If the stress intensity is reduced, this process proceeds backward, thereby releasing the clamp arms 341a from the cylinder of the contact surface 340, and allowing relative movement of the two layers, which are part of the contact surfaces 340, 341. As long as the load intensity is sufficiently high to maintain the clamped state, only a relative movement of the two contact surfaces along the length 340 aof the cylinder of the contact surface 340 is possible. Rotational and horizontal movements not along the length 340 aof the cylinder are blocked.FIG. 3I shows an embodiment 308 of two contact surfaces 340, 341. The contact surface 340 is formed here, similar to the contact surface 340 of the embodiment 307, in the form of a cylinder 340 bexpanded in the longitudinal direction 340 a. The contact surface 341 has two arms 341 athat are configured to be bent up after being brought into contact with the contact surface 340 based on a sufficiently large stress intensity. As a result, a latching region 341 b, which is configured to receive the cylinder 340 b, opens. The contact surface 341 is formed such that, as soon as the cylinder 340 bis located in the latching region 341 b, the arms 341 aare brought back into their starting position, whereby the cylinder 340 bis enclosed in the latching region 341 b. Embodiment 308 thus provides a snap-in function of the two contact surfaces, wherein the characteristics explained above with respect to the snap-in function of embodiment 303 are also applicable here.FIG. 3J shows an embodiment 309 of two contact pads 340, 341 configured to allow a rotational movement between the adjacent layers, which they are part of, after being brought into contact based on a sufficiently high stress intensity. The contact surface 340 is in this case in the form of a circular section, wherein the circular circumference represents a rounded elevation. The contact surface 341 has a recess corresponding to the ridge configured to receive the ridge of the contact surface 340. This can be advantageous in order to achieve a special force transmission between adjacent layers during twist movements and / or twistings within the sole.FIG. 3K shows an embodiment 311 of two contact surfaces 340, 341 which are configured to allow a rotational movement between the adjacent layers, the part of which are them, after being brought into contact based on a sufficiently high stress intensity. For exemplary embodiment 311, the same one explained already with respect to exemplary embodiment 305 is equally applicable, with the difference that the contact surfaces 340, 341 do not have a (ball) round shape, but a rounded cone shape. This may be advantageous in order to achieve accurate alignment of the two adjacent layers. Furthermore, the rounded cone shape can provide a better guidance in order to get with the contact surface 340 into the receiving region of the contact surface 341 even in the event of a horizontal relative displacement of both layers possibly occurring.FIG. 3L shows an embodiment 312 of two contact surfaces 340, 341 configured to allow a rotational movement between the adjacent layers, which they are part of, after being brought into contact based on a sufficiently high stress intensity. Embodiment 312 represents a modification to embodiment 311, in which the contact surface 341 can support the contact surface 340 in a resilient manner in addition to the property of preventing horizontal relative movements of the two layers. This is based on the spiral configuration of the contact surface 341. The additional suspension that may be provided by contact surface 341 allows to configure a layer of a sole with a plurality of these contact surfaces, whereby a cushioning characteristic of the sole is further adjustable in addition to the non-linear compressibility described herein. For example, a layer of different damping zones can be provided on the basis of contact surfaces 341 with different levels of damping.FIG. 4 shows a diagram 400 which indicates an exemplary profile 405 of a relative stress intensity (plotted on the y-axis) exerted on an embodiment of a sole according to the present invention as a function of a relative sole compression (plotted on the x-axis) resulting therefrom. The load intensity is given here as a fraction of a maximum force for which the sole is set up. For example, the maximum force for a shoe size of UK 8.5 may be 2000 Newtons or for a shoe size of UK 5.5 1625 Newtons. The sole compression is expressed as a percent degree of compression in relation to a sole extension in the unloaded state, wherein the sole extension may be a sole thickness or a sole height. For example, an embodiment of a sole according to the present invention can have an extension in the damping direction, i.e. in the direction perpendicular to the contact surface of a sole with the underlying surface when used, of 20 mm in the unloaded state. If the extension of this sole in the loaded state is only 15 mm, this would correspond to a sole compression of 25%.The curve 405 shown in FIG. 4 is based on a sole with three layers produced additively and can be divided into three zones 401, 402, 403. In the first zone 401, a stress intensity of up to 20% of the maximum force is applied to the sole. In this case, both the contact surfaces between the first and second layers and the contact surfaces between the second and third layers are spaced apart. The sole compression is essentially based on the compression of the first layer, which has the greatest compressibility among the three layers.If the stress intensity is increased above the value of 20% of the maximum force, the contact surfaces between the first and second layers begin to touch, which is shown as second zone 402 in curve 405. In the second zone 402, the second layer now also contributes to the degree of overall compression of the sole, which can also be referred to as activating the second layer. The second layer has a medium compressibility compared to the first and third layers. Since the overall compression of the sole in the second zone 402 is substantially provided by the second layer, the gradient of the course 405 in the second zone 402 changes. Thus, more force is required as a percentage compared to the first zone 401 to achieve an equal amount of compression. Activating the second layer at the transition from the first zone 401 to the second zone 402 results in the knee shown in diagram 400 in curve 405.If the stress intensity is increased further beyond a value of 50% of the maximum force, the contact surfaces between the second and third layers additionally begin to touch, which is shown as third zone 403 in curve 405. In the third zone 403, the third layer of the sole now also contributes to the degree of overall compression. The third layer is accordingly activated at the transition to the third zone 403. The third layer has a greater compressibility than the first or second layer. Since the overall compression of the sole is provided substantially by the third layer in the third zone 403, the gradient of the course 405 changes again in the third zone 403. Activating the third layer at the transition from the second zone 402 to the third zone 403 results in the knee shown in the diagram 400 in the course 405.If the stress intensity is increased further above 80%, the additively manufactured layer, for example a lattice structure, is overcompressed and loses its damping properties based on a structure of the layer. In this region, the structures constituting an additively manufactured layer, such as nodes and connecting elements between the nodes, are at least partially no longer spaced apart, but rather are in contact with adjacent structures. At such high load intensities, the compressibility of the sole is essentially determined only by the sole material itself and no longer by the structure constituting the respective layer. This behavior of a sole is also referred to as "forming the ground" and is not shown in diagram 400.The compression behavior of a sole according to the present invention thus has a non-linear behavior, which is shown by the bends in the course 405. The limit values shown in diagram 400 are to be understood here merely as examples. In other embodiments, the percentages of stress intensity as well as that of sole compression may vary. The non-linear damping behavior provides the advantageous properties described herein provided by an embodiment according to the present invention.In summary, the present invention thus provides a sole which is constructed from at least two layers produced additively. Adjacent layers and layers arranged at least partially one above the other do not have a continuous connection here, but can be spaced apart at least in partial regions depending on the stress intensity exerted on the sole. With increasing stress intensity, adjacent layers can be brought into contact, whereby compressibility of the sole changes abruptly, in particular decreases. As a result, the present invention provides a sole in which a damping characteristic can be specially adapted for different load intensities. It should be noted that a sole according to the present invention may comprise adjacent layers made up of a plurality of the contact surfaces described herein. In this case, the present invention should not be limited to a single embodiment of the contact surfaces. Rather, advantageous zones with different properties can be produced in a sole by a combination of different embodiments of the contact surfaces.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 2014 / 100462

[0004] EP 3 155 917 B1

[0005]

Claims

A sole (100), in particular a midsole, for a sports shoe, comprising: a first additively manufactured layer (110, 210, 310); and a second additively manufactured layer (120, 220, 320); wherein a bottom side of the second layer is arranged in at least a first area on a top side of the first layer; and wherein the sole is configured such that, while the sole is subjected to a first stress intensity, a first contact surface (140, 240, 340) of the top side of the first layer and a second contact surface (141, 241, 341) of the bottom side of the second layer are arranged spaced apart from each other in the first area.The sole of claim 1, wherein the first stress intensity corresponds to a force in the range of zero to 20 percent of a maximum force for which the sole is configured.Sole according to claim 1 or 2, wherein the sole is configured such that, while the sole is subjected to a second stress intensity that is greater than the first stress intensity, the first contact surface of the top side of the first layer and the second contact surface of the bottom side of the second layer are at least partially in contact with each other in the first region.Sole according to claim 3, wherein the second stress intensity corresponds to a force in the range of greater than 20 percent, in particular up to 50 percent, of a maximum force for which the sole is arranged.The sole according to claim 3 or 4, wherein the sole is configured such that when the first contact surface of the top side of the first layer and the second contact surface of the bottom side of the second layer are at least partially in contact with each other in the first area, the sole is still compressible.The sole according to any one of claims 3 to 5, wherein the sole is configured such that when the sole is subjected to the first stress intensity, the sole has a greater compressibility than when the sole is subjected to the second stress intensity.Sole according to any one of claims 1 to 6, wherein the sole comprises a third additively manufactured layer (130, 330).The sole of claim 7, wherein a bottom surface of the third layer is disposed in at least a second region on a top surface of the second layer.The sole according to claim 8, wherein the sole is configured such that, while the sole is subjected to the first or the second stress intensity, a third contact surface (142, 342) of the upper side of the second layer and a fourth contact surface (143, 343) of the lower side of the third layer are arranged spaced apart from each other in the second region.Sole according to claim 8 or 9, wherein the sole is configured such that, while the sole is subjected to a third stress intensity that is greater than the second stress intensity, the third contact surface of the top side of the second layer and the fourth contact surface of the bottom side of the third layer are at least partially in contact with each other in the second region.Sole according to claim 10, wherein the third stress intensity corresponds to a force in the range of greater than 50 percent, in particular up to 80 percent, of a maximum force for which the sole is arranged.The sole according to claim 10 or 11, wherein the sole is configured such that, while the sole is subjected to the third stress intensity, the first contact surface of the top side of the first layer and the second contact surface of the bottom side of the second layer are at least partially in contact with each other in the first region.The sole according to any one of claims 10 to 12, wherein the sole is configured such that when the sole is subjected to the first or second stress intensity, the sole has a greater compressibility than when the sole is subjected to the third stress intensity.Sole according to any of claims 1 to 13, wherein the first layer has a first lattice structure and / or wherein the second layer has a second lattice structure.Sole according to one of claims 1 to 14, wherein the first and the second layer comprise a different lattice structure, in particular wherein a compressibility of the second lattice structure is less than a compressibility of the first lattice structure.The sole according to any one of claims 7 to 15, wherein the third layer has a third lattice structure.Sole according to any one of claims 7 to 16, wherein the first, the second and the third layer comprise a different lattice structure, in particular wherein compressibility of the lattice structure decreases from the first lattice structure via the second lattice structure to the third lattice structure.The sole according to any one of claims 1 to 17, wherein a maximum force for which the sole is configured depends on a size of a shoe for which the sole is provided.Sole according to any of claims 1 to 18, wherein the top side of the first layer comprises a plurality of first contact surfaces and the bottom side of the second layer comprises a plurality of second contact surfaces, wherein superposed first and second contact surfaces are arranged such that, while the sole is subjected to the first stress intensity, the superposed first and second contact surfaces are spaced apart.The sole of claim 19, wherein the superposed first and second contact surfaces of the first and second layers are configured such that, while the sole is subjected to the second intensity of stress, the superposed first and second contact surfaces are at least partially in contact with each other.Sole according to any of claims 1 to 20, wherein the upper side of the second layer comprises a plurality of third contact surfaces and the lower side of the third layer comprises a plurality of fourth contact surfaces, wherein superposed third and fourth contact surfaces are arranged such that, while the sole is subjected to the first or the second stress intensity, the superposed third and fourth contact surfaces are spaced apart.The sole according to claim 21, wherein the third and fourth contact surfaces arranged one above the other are configured such that, while the sole is subjected to the third stress intensity, the third and fourth contact surfaces arranged one above the other are at least partially in contact with each other.Sole according to claim 21 or 22, wherein the superimposed first and second contact surfaces are arranged such that, while the sole is subjected to the third stress intensity, the superimposed first and second contact surfaces are at least partially in contact with each other.The sole according to any one of claims 19 to 23, wherein at least a first part of the first and second contact surfaces has a substantially flat shape.Sole according to any of claims 19 to 24, wherein at least a second part of the first and second contact surfaces has a shape adapted to prevent horizontal movement between the first and second layers in at least one direction when the at least second part of the first and second contact surfaces is in contact.Sole according to any of claims 19 to 25, wherein at least a third part of the first and second contact surfaces has a shape adapted to allow a rotational movement between the first and second layers when the at least third part of the first and second contact surfaces is in contact.Sole according to any of claims 19 to 26, wherein at least a fourth part of the first and second contact surfaces has a shape configured to prevent a horizontal movement and a rotational movement between the first and second layers when the at least fourth part of the first and second contact surfaces is in contact.Sole according to any of claims 19 to 27, wherein at least a fifth part of the first and second contact surfaces has a shape adapted to at least partially maintain a compressed state of the first and second layers by means of a snap-in function.The sole of claim 28, wherein the form is further configured to release the snap-in function based on a re-compression movement.Sole according to any of claims 19 to 29, wherein at least a sixth part of the first and second contact surfaces has a wave shape, wherein the wave shapes of the first and second contact surfaces are configured such that a wave crest of the first layer is configured to engage a wave trough of the second layer while the sole is subjected to the second stress intensity and / or such that a wave trough of the first layer is configured to engage a wave crest of the second layer while the sole is subjected to the second stress intensity.Sole according to claim 30, wherein the sole is configured such that the respective wave valleys and wave valleys of the first layer engage different wave valleys and wave valleys of the second layer depending on a horizontal force applied to the first and / or second layer.Sole according to any of claims 21 to 31, wherein at least a seventh part of the third and fourth contact surfaces has a substantially flat shape.Sole according to any of claims 21 to 32, wherein at least an eighth part of the third and fourth contact surfaces has a shape adapted to prevent horizontal movement between the second and third layers in at least one direction when the at least eighth part of the third and fourth contact surfaces is in contact.Sole according to any of claims 21 to 33, wherein at least a ninth part of the third and fourth contact surfaces has a shape adapted to allow a rotational movement between the second and third layers when the at least ninth part of the third and fourth contact surfaces is in contact.Sole according to any of claims 21 to 34, wherein at least a tenth part of the third and fourth contact surfaces has a shape adapted to prevent a horizontal movement and a rotational movement between the second and third layers when the at least tenth part of the third and fourth contact surfaces is in contact.Sole according to any of claims 21 to 35, wherein at least an eleventh part of the third and fourth contact surfaces has a shape adapted to at least partially maintain a compressed state of the second and third layers by means of a snap-in function.The sole of claim 36, wherein the shape is further configured to release the snap-in function based on a re-compression movement.Sole according to any of claims 21 to 37, wherein at least a twelfth part of the third and fourth contact surfaces has a wave shape, wherein the two wave shapes are configured such that a wave crest of the second layer is configured to engage a wave trough of the third layer while the sole is subjected to the third stress intensity and / or such that a wave trough of the second layer is configured to engage a wave crest of the third layer while the sole is subjected to the third stress intensity.Sole according to claim 38, wherein the sole is configured such that the respective wave valleys and wave valleys of the second layer engage different wave valleys and wave valleys of the third layer depending on a horizontal force applied to the second and / or third layer.Sole according to any one of claims 1 to 39, wherein at least one layer, two layers or three layers from the amount of the first, second and third layers has been produced by means of a method from: powder bed based method, in particular selective laser sintering, high speed sintering, or multi jet fusion method; material extrusion method, in particular melt filament production method or melt lamination method; VAT polymerization method, in particular stereolithography method, digital light processing method, or digital light synthesis; or material jetting method, in particular polyjet method.Sole according to any of claims 1 to 40, wherein the sole comprises at least one material of: thermoplastic elastomers, thermoplastic polyurethanes, polypropylene, polyamide 12, thermoplastic polyamide elastomers, thermoplastic polyester elastomers, acrylonitrile butadiene styrene copolymer, polylactide, polyethylene terephthalate glycol, polyvinyl acetate, high impact polystyrene, elastomeric polyurethane, photopolymers in general, acrylic polymers.

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