WO2025237718A1

WO2025237718A1 - Sole assembly with tensile layer

Info

Publication number: WO2025237718A1
Application number: PCT/EP2025/062223
Authority: WO
Inventors: Eric Hullegie
Original assignee: On Clouds GmbH
Current assignee: On Clouds GmbH
Priority date: 2024-05-14
Filing date: 2025-05-05
Publication date: 2025-11-20
Anticipated expiration: 2026-11-14

Abstract

The present disclosure relates to a sole assembly (1) extending in a longitudinal direction (L) from a heel area (HA) across a midfoot area (MA) to a forefoot area (FA). The sole assembly (1) comprises a midsole (2) extending in a vertical direction (V) from an upper surface (2U) configured to face an upper to a lower surface (2L) configured to face an outsole (7). The sole assembly (1) further comprises one or more tensile layers (3, 4, 5) connected to the midsole (2) and extending along the longitudinal direction (L) and/or along a transversal direction (T). Further disclosed are a method of manufacturing a sole assembly, a shoe comprising the sole assembly and the use of the sole assembly for manufacturing a shoe.

Description

Sole Assembly with Tensile Layer

Field of disclosure

The present invention relates to as sole assembly, a method of manufacturing a sole assembly, and a shoe.

Background of the invention

Cushioning and energy return are important performance parameters of footwear, especially athletic footwear. Many different approaches have been developed to optimize cushioning and energy return. Some of the known approaches focus on energy return plates, such as plates with a specific geometry or shape, or made of a specific material that balances stability, rigidity and elasticity. Other approaches focus on the sole unit more broadly, using, for example, gel cores or air cushions in the heel area of the shoe to increase the cushioning of the shoe and thus reduce the strain on the wearer's musculoskeletal system. Another strategy explored in the prior art focuses on sole designs that include vertically arranged spring elements in the heel area. When walking, the sole typically makes initial contact with the ground in the heel area. The vertical spring elements are compressed under the influence of the wearer's weight and are released when the foot pushes off the ground.

Summary of disclosure

The prior art approaches to energy return suffer from a number of disadvantages. In particular, many of the sole constructions displaying good cushioning and energy return properties suffer from relatively high weight, low stiffness or both. The low stiffness may for example lead to a lack of stability, which increases the risk of incidents, such as twisting an ankle of the wearer. The relatively high weight is often a result of the sophisticated structures involved, such as complex plates with a specific geometry or shape. A further challenge is to find an adequate balance between flexibility and stiffness or rigidity. While flexibility may be desired to achieve good cushioning and propulsion, stiffness or rigidity may be desired at the same time order to impart stability and to prevent energy loss.

A further deficiency of the prior art sole constructions is their low efficiency of energy return, i.e. , only a fraction of the energy of a heel strike can be returned. In addition, many energy return devices in the prior art suffer from an unbalanced distribution of energy return across the surface of the shoe. For example, during treading, different areas of the sole experience different pressure profiles, and these different pressure profiles should ideally be accommodated by the energy return unit.

As a result, there is a need to provide shoes with improved energy return, cushioning, stiffness and low weight.

It is therefore the general object of the present disclosure to address and preferably to overcome at least some of the deficiencies identified in the prior art sole assemblies. In at least some embodiments, it is an object to provide a sole assembly striking a beneficial balance between stiffness and high energy return. It is a further object of at least some variants to provide a sole assembly having a low weight. In at least some embodiments, it is a further object to provide a sole assembly that is easy to manufacture and that may ideally be manufactured from existing midsoles. It is a further object of at least some variants to provide a sole assembly that minimizes energy loss during running and that maximizes energy return and a quick push-off from the ground for the wearer.

The general object is achieved by the subject-matter of the independent claim. Further advantageous embodiments follow from the dependent claims and the overall disclosure.

A first aspect of the present disclosure relates to a sole assembly extending in a longitudinal direction from a heel area across a midfoot area to a forefoot area. The sole assembly comprises a midsole extending in a vertical direction from an upper surface configured to face an upper to a lower surface configured to face an outsole. The sole assembly further comprises one or more tensile layers connected to the midsole. The one or more tensile layers extend along the longitudinal direction and/or along a transversal direction orthogonal to the longitudinal direction. Typically, the one or more tensile layers are arranged such that at least a portion of the respective tensile layer experiences a tensile force when the lower surface of the midsole is bent in a vertical direction away from the lower surface of the midsole. Typically, the tensile force is experienced in a general direction of extension of the tensile layer. For example, in some variants, the tensile force may be experienced in a direction essentially orthogonal to the vertical direction, such as in the longitudinal direction and/or in the transversal direction.

During a gait cycle, the midsole is elastically bent in the vertical direction. More specifically, the lower surface of the midsole is bent outwardly during the gait cycle, which causes stretching of the lower surface of the midsole during the gait cycle. The sole assembly of the present disclosure includes one or more tensile layers connected to the midsole and extending along the longitudinal direction and/or along the transversal direction. Thereby, outward bending of the lower surface of the midsole in the vertical direction during the gait cycle is reduced. More specifically, bending of the lower surface of the midsole in a vertical direction away from the lower surface of the midsole during the gait cycle is reduced. By reducing outward bending of the lower surface, energy loss is minimized and more energy is available for return to the wearer during push-off from the ground.

The outward bending during the gait cycle outlined in the previous paragraph refers in particular to the outward bending occurring during the heel-off phase of the gait cycle and during the toe-off phase of the gait cycle.

A further advantage of the one or more tensile layers is that the overall stiffness of the sole assembly may be optimized and increased, resulting in enhanced foot stability for the wearer.

Directional indications as used in the present disclosure are to be understood as follows:

The longitudinal direction L of the sole assembly, respectively the shoe, is described by an axis from the heel area, respectively from the heel edge, to the forefoot area, respectively to the shoe tip/toe tip, and thus extends along the longitudinal axis of the sole assembly or shoe. Thus the term “extending along/in the longitudinal direction” typically refers to extending towards the shoe tip, respectively toe tip, and the term “extending against the longitudinal direction” typically refers to extending towards the heel edge. The transversal direction T of the sole assembly respectively the shoe, extends transversely to the longitudinal axis and substantially parallel to the ground in the operative state. Thus, the transversal direction runs along a transversal axis of the sole assembly, respectively the shoe. In the context of the present disclosure, the vertical direction V denotes a direction from an upper surface of the midsole to a lower surface of the midsole, or in the operative state in the direction of the foot of the wearer, and thus runs along a vertical axis of the sole assembly, respectively the shoe. Thus, the term “extending along/in the vertical direction” typically refers to extending towards the lower surface of the midsole, and the term “extending against the vertical direction” typically refers to extending towards the upper surface of the midsole. The longitudinal direction, the vertical direction and the transverse direction may all be perpendicular to each other. The indication “horizontal” refers to a plane extending in the longitudinal and the transverse direction and being perpendicular to the vertical direction. The lateral side of the sole assembly, respectively the shoe, is the outer perimeter of the sole assembly, respectively the shoe, between the heel edge and the shoe tip/toe tip, which in the worn state rests against the outer instep of the wearer's foot. The medial side of the sole assembly, respectively the shoe, refers to the inner perimeter of the sole assembly, respectively the shoe, between the heel edge and the shoe tip/toe tip, which is located opposite the lateral side. Thus, in a pair of worn running shoes, the medial sides of the two running shoes face each other and the lateral sides face away from each other. Furthermore, the sole assembly, respectively the shoe, may typically along the longitudinal direction be divided into a forefoot area, a heel area and a midfoot area being arranged between the forefoot area and the heel area. For example, the forefoot area extends from the shoe tip against, i.e. opposite, the longitudinal direction to 30-45% of the total length of the sole assembly, respectively the shoe, in the longitudinal direction. The heel area extends, for example, from the heel edge in the longitudinal direction to 20-30% of the total length of the sole assembly, respectively the shoe, in the longitudinal direction. The midfoot area extends directly between the heel area and the forefoot area, such that the length in the longitudinal direction of the midfoot area makes up the remaining portion of the total length, particularly from 15-50% of the total length.

The upper as used herein is configured for receiving the foot of a wearer and for securing the foot to the shoe. Typically, the sole assembly is at least partially arranged in the vertical direction underneath the upper.

Depending on the application, the midsole assembly may have one or more tensile layers. For example, in some variants, the midsole assembly comprises from one to ten tensile layers, preferably from one to six tensile layers. The different tensile layers may or may not contact each other. Independently and regardless of whether the tensile layers contact each other or not, in some variants, the different tensile layers are separately formed, i.e. they are not integrally formed.

Depending on the application, the tensile layers may have different tensile strengths. For example, the one or more tensile layers may be configured to minimize outward bending of the lower surface of the midsole in the vertical direction during the gait cycle. To this end, in some variants, the one or more tensile layers have a tensile strength in the longitudinal direction that is at least 10%, preferably at least 30%, more preferably at least 50%, even more preferably at least 100% higher compared to a tensile strength in the longitudinal direction of the midsole. Alternatively or in combination, in some variants, the one or more tensile layers have a tensile strength in transversal direction that is at least 10%, preferably at least 30%, more preferably at least 50%, even more preferably at least 100%, higher compared to a tensile strength in transversal direction of the midsole. It is understood that although the tensile strengths indicated refer to the longitudinal direction (respectively the transversal direction) in the assembled sole assembly, the tensile strengths of the tensile layers and of the midsole are measured for the tensile layers and for the midsole individually and separately. In other words, the tensile strength of the tensile layers refers to their tensile strength without being connected to the midsole. Likewise, the tensile strength of the midsole refers to the midsole without being connected to the one or more tensile layers. In some variants, the one or more tensile layers have a tensile strength in the longitudinal direction, as measured according to ASTM D2256 in the version of 2010, of at least 0.1 GPa, preferably at least 0.5 GPa, more preferably at least 1 GPa, even more preferably at least 2 GPa, such as at least 3 GPa. Alternatively or in combination, in some variants, the one or more tensile layers have a tensile strength in the transversal direction, as measured according to ASTM D2256 in the version of 2010, of at least 0.1 GPa, preferably at least 0.5 GPa, more preferably at least 1 GPa, even more preferably at least 2 GPa, such as at least 3 GPa. In some variants, the one or more tensile layers may each be made of a material having a tensile strength, as measured according to ASTM D2256 in the version of 2010, of at least 0.1 GPa, preferably at least 0.5 GPa, more preferably at least 1 GPa, even more preferably at least 2 GPa, such as at least 3 GPa.

Depending on the application, the one or more tensile layers may be made of different materials. For example, in some variants, the one or more tensile layers are made of polyethylene with ultra-high-molecular-weight (PE-UHMW), polyamide, carbon fiber, polysulfone, polyether sulfone, polyester, or a mixture or copolymer thereof. In some variants, the one or more tensile layers are made of a thermoplastic or a thermosetting polymer. In some variants, the one or more tensile layers comprise, or consist of, Dyneema® or Spectra®. For example, the one or more tensile layers may comprise at least 30 wt%, preferably at least 50wt%, more preferably at least 80 wt%, Dyneema® or Spectra®. In some variants, the one or more tensile layers are made of Dyneema® or Spectra®.

It is generally understood herein that in a typical embodiment, “polyethylene with ultra-high- molecular-weight (PE-UHMW)”, also known as “high-modulus polyethylene (HMPE)”, denotes a polyethylene with long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain may serve to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. Alternatively or additionally, UHMWPE can be defined to have an average molecular weight of up to 6.000.000 g/mol, and a density of 0.8 - 1 g/cm3, preferably 0.87 - 0.94 g/cm3 more preferably of 0.93-0.94 g/cm3. Preferably, the UHMWPE has less than 1 side chain per 100 C atoms, more preferably less than 1 side chain per 300 C atoms. Preferably, the polyethylene fibers have deniers per filament (dpf) in the range of from 0.1 to 50, more preferably from 0.5 to 20, most preferably from 1 to 10 dpf. The polyethylene yarns preferably are preferably from 200 to 50000, more preferably from 500 to 10000, most preferably from 800 to 4800 denier.

Depending on the application, the one or more tensile layers may be made of different materials. For example, in some variants, the one or more tensile layers are each made of a fabric. In some variants, each of the one or more tensile layers comprises, or consists of, a plurality of tensile filaments. For example, each of the one or more tensile layers can be made of tensile filaments. The tensile filaments may in some variants be threads, fibers, yarns or other filamentous materials. In some variants, each of the one or more tensile layers is a tensile fabric formed from the plurality of tensile filaments. For example, the tensile filaments of each respective tensile fabric may in some variants be woven, knitted or otherwise intertwined to form the respective tensile fabric, or they may be bonded together to form the respective tensile fabric. Thus, the tensile fabric could e.g. be a woven, knitted, or non-woven fabric.

In some variants, the tensile filaments may be made of polyethylene with ultra-high- molecular-weight (PE-UHMW), polyamide, carbon fiber, polysulfone, polyether sulfone, polyester, or a mixture or copolymer thereof. In some variants, the tensile filaments are made of a thermoplastic or a thermosetting polymer. In some variants, the tensile filaments comprise, or consist of, Dyneema® or Spectra®. For example, the tensile filaments may comprise at least 30 wt%, preferably at least 50wt%, more preferably at least 80 wt%, Dyneema® or Spectra®. In some variants, the tensile filaments are made of Dyneema® or Spectra®.

Depending on the application, the tensile filaments may have different tensile strengths and tensile moduli. For example, in some variants, the tensile filaments have a tensile strength, as measured according to ASTM D2256 in the version of 2010, of preferably at least 1.2 GPa, more preferably at least 2.5 GPa, most preferably at least 3.5 GPa. The tensile modulus of the tensile filaments, as measured according to ASTM D2256, is preferably at least 30 GPa, more preferably at least 50 GPa, most preferably at least 60 GPa.

Depending on the application, the one or more tensile layers have different properties. For example, in some variants, the one or more tensile layers have a high tensile force but are at the same time compressible. In some variants, the one or more tensile layers are compressible in the longitudinal direction. Alternatively or in combination, in some variants, the one or more tensile layers are compressible in the transversal direction.

Depending on the application, compressibility of a given object may be defined as the force required to compress that particular object in the longitudinal direction respectively in the transversal direction. For example, the compressibility of a tensile layer may be defined as the force required to compress the tensile layer along the longitudinal direction respectively along the transversal direction.

In some variants, the one or more tensile layers may have a compressibility in the longitudinal direction that is at least 20% higher, preferably at least 50% higher, more preferably at least 80% higher, even more preferably at least 100%, in some variants even at least 150% higher, in some variants even at least 300% higher, than a compressibility in the longitudinal direction of the midsole. In some variants, the compressibility in longitudinal direction of the one or more tensile layers may be at least two times, e.g. at least four times, as large as the compressibility in longitudinal direction of the midsole. As an example, when the midsole is made of a pebax foam and the tensile layers are made of dyneema® fabric, then the compressibility in the longitudinal direction of the tensile layers may be significantly larger than that of the midsole.

In some variants, the one or more tensile layers may have a compressibility in the transversal direction that is at least 20% higher, preferably at least 50% higher, more preferably at least 80% higher, even more preferably at least 100%, in some variants even at least 150% higher, in some variants even at least 300% higher, than a compressibility in the transversal direction of the midsole. In some variants, the compressibility in transversal direction of the one or more tensile layers may be at least two times, e.g. at least four times, as large as the compressibility in transversal direction of the midsole. As an example, when the midsole is made of a pebax foam and the tensile layers are made of dyneema® fabric, then the compressibility in the transversal direction of the tensile layers may be significantly larger than that of the midsole. The embodiments described in this paragraph (which relates to the transversal direction) may be provided alternatively to or additionally to the embodiments described in the previous paragraph (which relates to the longitudinal direction).

One advantage of the embodiments described in the previous paragraphs is that they provide a beneficial balance between rigidity and flexibility. For example, rigidity may be provided to enhance stability and to minimize excessive and undesirable outward bending of the midsole during the gait cycle, while bending in other directions may not be affected. Furthermore, an overall low weight may be achieved using these variants.

Depending on the application, the one or more tensile layers may be compressible in one or more directions. For example, in some variants, the one or more tensile layers have the same compressibility in the longitudinal direction as they do in the transversal direction. For example, the one or more tensile layers may in some variants be compressible in longitudinal direction and in transversal direction. The transversal direction is orthogonal to the longitudinal direction and to the vertical direction. Depending on the application, the one or more tensile layers may have a compressibility in the transversal direction that is at least 20% higher, preferably at least 50% higher, more preferably at least 80% higher, even more preferably at least 100% higher, in some variants even at least 150% higher, than a compressibility in the transversal direction of the midsole. In some variants, the compressibility in transversal direction of the one or more tensile layers may be at least two times, e.g. at least four times, as large as the compressibility in transversal direction of the midsole.

The tensile layer is connected to the midsole and extends along the longitudinal direction and/or along the transversal direction. It is understood that the tensile layer may, but does not have to, extend parallel to a longitudinal axis. In some variants, the tensile layer extends along the longitudinal direction and along a transversal direction orthogonal to the longitudinal direction. For example, at least a portion of the tensile layer may extend both along the longitudinal direction and along a transversal direction orthogonal to the longitudinal direction. Thus, the tensile layer may have at least an extension along the longitudinal axis and/or may have at least an extension along a transversal axis.

Depending on the application, the one or more tensile layers may be connected to the midsole in different ways. For example, the one or more tensile layers may be directly or indirectly connected to the midsole. The way through which the one or more tensile layers are connected to the midsole may differ for different tensile layers, if there are two or more tensile layers. For example, in some variants, the sole assembly comprises two or more tensile layers. A first tensile layer may for example be arranged on the lower surface of the midsole, e.g. the first tensile layer may contact the lower surface of the midsole. Depending on the application, a second tensile layer may for example be arranged on the first tensile layer, for example in the vertical direction on a lower face of the first tensile layer facing away from the midsole. In some variants, the second tensile layer does not contact the midsole, but may for example be said to be at least indirectly connected to the midsole, namely through the intermediacy of the first tensile layer. In further variants, the second tensile layer may also contact the midsole and thereby be directly connected to the midsole. For example, in some variants, the second tensile layer may be arranged within the midsole or on an upper surface of the midsole.

Depending on the application, different approaches may be used to connect the one or more tensile layers to the midsole. For example, in some variants, at least one of the one or more tensile layers is materially bonded to the midsole, preferably by lamination, comolding, welding, sewing or through an adhesive. Preferably, all of the one or more tensile layers are connected to the midsole in the same way. For example, preferably, all of the one or more tensile layers are materially bonded to the midsole, preferably by lamination, co-molding, welding, sewing or through an adhesive. In some variants, each of the one or more tensile layers directly contacts the midsole. Alternatively or in combination, each of the one or more tensile layers may directly contact an outsole.

In some variants, the sole assembly comprises at least two tensile layers not contacting each other. In further variants, the sole assembly comprises at least two tensile layers at least partially contacting each other. Alternatively or in combination with any of these variants, in some variants, all tensile layers of the sole assembly at least partially contact the midsole. For example, in some variants, at least 20%, more preferably at least 40%, of an outer surface of each tensile layer contacts the midsole.

Alternatively or in combination, in some variants, at least 20%, more preferably at least 40%, even more preferably at least 60%, even more preferably at least 80%, even more preferably at least 90%, even more preferably 100%, of an outer surface of each tensile layer does not contact another tensile layer. In some variants, each tensile layer has a distance of at least 0.5 mm, preferably at least 1 mm, more preferably at least 3 mm, such as at least 5 mm, from each other tensile layer.

Depending on the application, the one or more tensile layers may have different shapes, geometries and arrangements. For example, in some variants, each of the one or more tensile layers has a layer thickness of less than 5 mm, preferably less than 1 mm, more preferably from 0.05 mm to 0.5 mm. The thickness may in particular relate to an extension in the vertical direction.

Depending on the application, the one or more tensile layers may have different lengths and widths. For example, in some variants, at least one of the one or more tensile layers has an extension in the longitudinal direction of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm, even more preferably at least 5 cm. As an example, in some variants, all of the one or more tensile layers may have an extension in the longitudinal direction of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm. In some variants, the one or more tensile layers may have an extension in the transversal direction of at least 0.3 mm, preferably at least 0.7 mm, more preferably at least 1 cm, even more preferably at least 2 cm, e.g. at least 4 cm. In some variants, at least one of the one or more tensile layers has an extension in the transversal direction of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm, even more preferably at least 5 cm. As an example, all of the one or more tensile layers may have an extension in the transversal direction of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm. It is understood, that if the sole assembly comprises two or more tensile layers, these may have different lengths and widths, or they may have essentially the same extension in the longitudinal direction and/or essentially the same extension in the transversal direction. It is also understood that the extension in the longitudinal direction may be chosen independently of the extension in the transversal direction.

In some variants, each of the one or more tensile layers has a surface area of at least 25 mm², preferably of at least 100 mm². The surface area of a tensile layer may for example refer to an upper or to an opposite lower surface area of the tensile layer.

Depending on the application, the one or more tensile layers may have different sizes and/or dimensions. For example, in some variants, the one or more tensile layers may be essentially flat and/or essentially aerial. However, in some variants, at least one of the one or more tensile layers may optionally be slot-shaped. For example, in these variants, at least one of the one or more tensile layers may optionally have an extension in the transversal direction that is significantly smaller compared to an extension in the longitudinal direction. As an example, in some variants, at least one of the one or more tensile layers may be formed from a plurality of tensile filaments extending essentially in parallel to each other and essentially in parallel to the longitudinal direction, without a significant extension in the transversal direction. It is also possible, in some variants, that all of the one or more tensile layers may be essentially slot-shaped. It is understood that these one or more slotshaped tensile layers may, but do not have to, extend parallel to a longitudinal axis. However, typically, these one or more slot-shaped tensile layers have at least some extension along the longitudinal direction. In some variants, at least one of the one or more tensile layers may optionally have an extension in the longitudinal direction that is significantly smaller compared to an extension in the transversal direction.

Depending on the application, the one or more tensile layers may have different orientations. For example, the one or more tensile layers may extend essentially parallel to a longitudinal axis. It is also possible that at least one of the one or more tensile layers may additionally have an extension in the transversal direction. Alternatively or in combination, in some variants, the one or more tensile layers may extend essentially parallel to the transversal direction. In these variants, it is possible, for example, that at least one of the one or more tensile layers may additionally have an extension in the longitudinal direction.

Depending on the application, the one or more tensile layers may have different arrangements with respect to the midsole. For example, in some variants, at least one of the one or more tensile layers may be arranged in a lower half of the midsole. In other words, in these variants, the at least one of the one or more tensile layers is arranged in the vertical direction closer to the lower surface of the midsole than to the upper surface of the midsole. For example, a first tensile layer may be arranged in the vertical direction closer to the lower surface of the midsole than to the upper surface of the midsole. Alternatively or in combination, a second tensile layer may have a different arrangement. For example, a second tensile layer may be arranged in the vertical direction closer to the upper surface of the midsole than to the lower surface of the midsole.

The exact position and arrangement of the one or more tensile layers with respect to the midsole may be used to optimize the physical and mechanical properties of the sole assembly. For example, the first tensile layer may be arranged at least partially, preferably fully, on the lower surface of the midsole. This variant may, for example, be chosen to increase the stiffness of the sole assembly. For example, it can be envisioned that outward bending of the lower surface of the midsole may be reduced more strongly if the first tensile layer is arranged at least partially on that lower surface (or at least within 3 mm, preferably within 1.5 mm, more preferably within 0.5 mm, of the lower surface of the midsole), compared to an equally conceivable arrangement in which the first tensile layer is at least partially arranged further inwardly within the midsole. In some variants, a first tensile layer is at least in the forefoot area of the sole assembly arranged either on the lower surface of the midsole, or at least within 3 mm, preferably within 1.5 mm, more preferably within 0.5 mm, of the lower surface of the midsole.

Depending on the application, a vertical position of the one or more tensile layers may or may not change. For example, in some variants, the one or more tensile layers are essentially parallel to the lower surface of the midsole. If the sole assembly comprises two or more tensile layers, it is possible that the different tensile layers may have different vertical positions or arrangements. For example, it is possible that only some of these tensile layers may be parallel to the lower surface of the midsole. It is also possible that a given tensile layer may be parallel to the lower surface of the midsole only in a certain area of the sole assembly. For example, in some variants, the first tensile layer is parallel to the lower surface of the midsole at least in the forefoot area of the sole assembly. It is possible, but not necessary, in these variants, that the first tensile layer extends beyond the forefoot area, and that the first tensile layer, in the midfoot area and/or in the heel area, may (or may not) be parallel to the lower surface of the midsole.

In some variants, the first tensile layer comprises at least a forefoot portion arranged in the forefoot area of the sole assembly. Additionally, in some variants, the first tensile layer further comprises a midfoot portion arranged in the midfoot area of the sole assembly. Alternatively or in combination, in some variants, the first tensile layer further comprises a heel portion arranged in the heel area of the sole assembly. Preferably, the entire forefoot portion of the first tensile layer is arranged in the vertical direction closer to the lower surface of the midsole than to the upper surface of the midsole. Alternatively or in combination, the entire midfoot portion of the first tensile layer may be arranged in the vertical direction closer to the lower surface of the midsole than to the upper surface of the midsole.

As used herein, the expression that a given tensile layer is arranged in a given area of the sole assembly (the possible areas being the forefoot area, the midfoot area and the heel area) preferably means that the given tensile layer extends across the respective area of the sole assembly for a distance of at least 1 cm, preferably for a distance of at least 2 cm, more preferably for a distance of at least 3 cm, along the longitudinal direction. Alternatively or in combination, the expression that a given tensile layer is arranged in a given area of the sole assembly (the possible areas being the forefoot area, the midfoot area and the heel area) may in some variants also mean that the given tensile layer extends across the respective area of the sole assembly for a distance of at least 1 cm, preferably for a distance of at least 2 cm, more preferably for a distance of at least 3 cm, along the transversal direction.

In some variants, the first tensile layer is arranged at least partially within the midsole and/or on the lower surface of the midsole. In some variants, the forefoot portion of the first tensile layer, and optionally also the midfoot portion of the first tensile layer, are each arranged within 15 mm, preferably within 10 mm, more preferably within 6 mm, even more preferably within 3 mm, of the lower surface of the midsole. In some variants, at least in the forefoot area, the first tensile layer (3) extends parallel to the outer surface of the midsole (2). Alternatively, in some variants, at least in the midfoot area and/or in the heel area, the first tensile layer may extend in parallel to the outer surface of the midsole.

Depending on the application, the one or more tensile layers may be arranged in different regions of the sole assembly. For example, in some variants, the one or more tensile layers are arranged in one or more of the followings areas: the heel area of the sole assembly, the midfoot area (MA) of the sole assembly and/or the forefoot area (FA) of the sole assembly. It is understood that if the sole assembly comprises two or more tensile layers, these may be arranged independently of each other. For example, a first tensile layer may be arranged at least partially in the forefoot area, while a second tensile layer may - independently of the first tensile layer - be arranged also at least partially in the forefoot area, or at least partially in another area.

In some variants, a first tensile layer is arranged only in the heel area of the sole assembly.

In other variants, the first tensile layer is arranged only in the heel area and in the midfoot area. In other variants, the first tensile layer is arranged in the heel area, in the midfoot area and in the forefoot area. In other variants, the first tensile layer is arranged only in the midfoot area. In other variants, the first tensile layer is arranged only in the midfoot area and in the forefoot area. In other variants, the first tensile layer is arranged only in the forefoot area. All of the variants described in this paragraph apply mutatis mutandis to any second tensile layer, and any further tensile layer, wherein the arrangement of each tensile layer may be chosen independently of each other tensile layer.

In some variants, the first tensile layer is arranged at least partially, preferably fully, between the midsole and an outsole.

Depending on the application, different midsoles may be used. The midsole may be made of different materials. In some variants, the midsole comprises at least 40 wt%, preferably at least 60 wt%, more preferably at least 80 wt%, even more preferably at least 95 wt%, even more preferably 100%, foam. For example, the midsole may consist of the foam. Depending on the application, different foams may be used. For example, the foam may be a polymer foam. For example, in some variants, the foam may be selected from: polyurethanes, in particular expanded polyurethanes, polyethers, polyethylenes, polyamides, polyvinyl acetates, polyether block amides, polyethylene vinyl acetate (EVA), polyolefins, polyesters, or mixtures, e.g. copolymers such as copolymers, thereof. Preferably, the midsole may be made of PEBAX®. As used herein, PEBAX® denotes block copolymers made up of polyamide blocks and polyether blocks.

In some variants, the sole assembly further comprises an outsole and/or an insole. Alternatively or in combination, the sole assembly may be devoid of a midsole plate or may comprise a midsole plate. The midsole plate may for example be a midsole board.

Depending on the application, the sole assembly may comprise two or more tensile layers, i.e. at least a first tensile layer and a second tensile layer.

The second tensile layer extends along the longitudinal direction and/or along the transversal direction, wherein at least a portion of the second tensile layer is arranged in the vertical direction closer to the upper surface of the midsole than to the lower surface of the midsole. In some variants, the second tensile layer is fully arranged in the vertical direction closer to the upper surface of the midsole than to the lower surface of the midsole. For example, the second tensile layer may be arranged in an upper half of the midsole. In some variants, the second tensile layer is arranged either on the upper surface of the midsole, or at least within 3 mm, preferably within 1 .5 mm, more preferably within 0.5 mm, of the upper surface of the midsole.

One advantage of the variants described in the previous paragraph is that they may for example be used to reduce bending of the upper surface of the midsole in a vertical direction away from the upper surface during the gait cycle.

In some variants, at least one tensile layer is sandwiched within the midsole. In other words, the midsole may comprise at least two layers being arranged on opposite sides of the respective at least one tensile layer in the vertical direction. In some variants, at least one tensile layer is arranged within, preferably fully encompassed by, the midsole. In some variants, for example, the second tensile layer is arranged within, preferably fully encompassed by, the midsole. In some variants, the sole assembly has an assembly, which is described in the vertical direction (from an upper surface downwards) as: midsole section - second tensile layer - further midsole section - first tensile layer. Thus, in this variant, the second tensile layer is sandwiched between two sections of the midsole and the second tensile layer is arranged in the vertical direction above the first tensile layer. The first tensile layer may for example be arranged outwardly in the vertical direction, comprising a lower face configured to contact the ground. In some variants, the sole assembly comprises even further layers, e.g. it may have a configuration of: midsole section - third tensile layer - further midsole section - second tensile layer - further midsole section - first tensile layer.

In some variants, the first tensile layer and the second tensile layer do not contact each other. For example, in some variants, the first tensile layer and the second tensile layer are arranged opposite each other with respect to the midsole. If the sole assembly further comprises a third tensile layer, it is possible, in some variants, that the first, second and third tensile layers do not contact each other.

In some variants, the sole assembly comprises a third tensile layer. Optionally, the sole assembly may comprise a fourth tensile layer and possibly even further tensile layers. In some variants, the third tensile layers arranged in the vertical direction between the first tensile layer and the second tensile layer.

Depending on the application, the one or more tensile layers may have different cross- sectional profiles. This may apply to a longitudinal cross-section, as well as to a transversal cross-section. In some variants, at least in the forefoot area and optionally also in the midfoot area and/or in the heel area, at least one of the one or more tensile layers (for example at least the first tensile layer) has an upper face that is concave in a longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction. Alternatively or in combination, in some variants, at least in the forefoot area and optionally also in the midfoot area and/or in the heel are, at least one of the one or more tensile layers (for example at least the first tensile layer) has an upper face that is either straight or concave in a transversal cross section parallel to the vertical direction and orthogonal to the longitudinal direction. The indicated cross-sectional profiles may apply for example to the first tensile layer. The indicated cross-sectional profiles may also apply, independently of the first tensile layer, to the second tensile layer.

The present disclosure relates in a second aspect to a method of manufacturing a sole assembly, preferably a sole assembly according to any of the embodiments described herein, preferably in the context of the first aspect of the disclosure.

As used herein, the upper face of the one or more tensile layers typically faces in a direction against the vertical direction. Typically, the upper face of the one or more tensile layers is configured to face an upper. The upper face of the one or more tensile layers typically faces away from an outsole. In some variants, for example, the upper face of the one or more tensile layers may face the upper surface of the midsole. The method of manufacturing a sole assembly comprises providing a midsole extending in a vertical direction from an upper surface configured to face an upper to a lower surface configured to face an outsole. The method of manufacturing a sole assembly further comprises connecting to the midsole one or more tensile layers such that they extend along the longitudinal direction and/or along the transversal direction.

In some variants, the one or more tensile layers are materially bonded to the midsole, preferably through lamination, printing, co-molding, heat-bonding, welding, sewing or through an adhesive.

The present disclosure relates in a third aspect to a shoe comprising a sole assembly according to any one of the embodiments described herein, preferably in the context of the first aspect of the disclosure.

The present disclosure relates in a fourth aspect to a use of the sole assembly according to any one of the embodiments described herein, preferably in the context of the first aspect of the disclosure, for manufacturing the shoe.

The present disclosure is described herein in the context of different aspects. However, the aspects are not to be understood as separate from each other but as part of a unified disclosure. Thus, all embodiments disclosed in the context of one aspect also relate to the other aspects of the disclosure, unless expressly states otherwise.

It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. Brief description of the figures

The disclosure described herein will be more fully understood from the detailed description given herein below and the accompanying drawings, which should not be considered limiting to the invention described in the appended claims. The drawings show:

Fig. 1 an embodiment of the sole assembly during the toe-off phase of the gait cycle;

Fig. 2 a further embodiment of the sole assembly in an idle state;

Fig. 3 shows a further embodiment of the sole assembly during the toe-off phase of the gait cycle.

Exemplary embodiments

Figure 1 shows an embodiment of a sole assembly 1 comprising a midsole 2. The midsole 2 comprises an upper surface 2U and a lower surface 2L. The sole assembly 1 is illustrated in figure 1 in a position during the toe-off phase of the gait cycle. In this phase, the forefoot area of the midsole closest to the ground normally elongates in the longitudinal direction L when the forefoot area of the shoe is bending. This bending would lead to energy loss due to energy partially going into flexing/elongating instead of going into a quick push-off.

However, excessive bending is minimized because the sole assembly 1 shown in figure 1 also comprises a first tensile layer 3, which in the illustrated embodiment is a fabric made of dyneema. Specifically, during the toe-off phase of the gait cycle, the dyneema layer, by virtue of its tensile strength, counteracts outward bending of the lower surface 2L of the midsole 2. The first tensile layer 3 may be arranged between the midsole 2 and an outsole 7, or close to an interface between the midsole 2 and the outsole 7. In the figures, including in figure 1 , the first tensile layer 3 is illustrated at a slight distance from the outsole in order to ensure that the layer illustrated in black can be clearly distinguished from the outsole, which is also illustrated in black. However, in some variants, the first tensile layer 3 is in fact arranged between the midsole 2 and the outsole 7, and contacts the outsole 7. Furthermore, the first tensile layer 3 may have a thickness of less than 0.5 mm.

The tensile layer 3 essentially acts as a stiffening element at a very low weight and overall thickness similar to that of a midsole board, but with better cushioning properties. Because of the reduced thickness, it leaves more room for high performing foam compared to when using a traditional midsole board or it can be used in addition to a midsole board.

Additionally, while the tensile layer 3 has a high tensile strength, it is also compressible. This allows to create stiffness when the midsole is bent in one direction while allowing deformation/flexwhen bending in the opposite direction. One advantage of this is that during the landing impact, the tensile layer 3 can be strategically placed so that it allows flexibility and deformation while providing added stiffness and limiting elongation of the midsole in the forefoot.

Furthermore, the sole assembly 1 illustrated in figure 1 also comprises a midsole plate 8.

Figure 2 shows a further embodiment of the sole assembly 1 , this time in an idle state. The sole assembly 1 shown in figure 2 comprises two tensile layers, namely a first tensile layer 3 and a second tensile layer 4. The first tensile layer 3 is arranged between the midsole 2 and an outsole 7. The second tensile layer 4 is arranged on an upper surface of the midsole 2U, and thereby opposite the first tensile layer 3 with respect to the midsole 2.

In a longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction, the first tensile layer 3 extends essentially in parallel to a lower surface of the midsole 2L. Further, in the longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction, at least in the forefoot area and also in the heel area, the first tensile layer 3 has an upper face 3U facing the upper surface of the midsole 2U, which upper face 3U is concave. In the midfoot area, the upper face 3U is essentially planar, at least in the longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction. Similarly, in the longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction, the second tensile layer 4 extends in parallel to an upper surface of the midsole 2U. Further, in the longitudinal cross section parallel to the vertical direction and parallel to the longitudinal direction, at least in the forefoot area FA, the second tensile layer 4 has an upper face 4U which is concave. In the midfoot area MA and in the heel area HA, the second tensile layer 4 has a more complex cross-sectional profile that includes an inflection point in the midfoot area MA.

Although this cannot be seen in the side view of figure 2, in a transversal cross section parallel to the vertical direction and orthogonal to the longitudinal direction, the upper face 3U of the first tensile layer 3 is slightly concave.

Furthermore, the sole assembly 1 illustrated in figure 2 does not comprise a midsole plate.

Figure 3 shows a further embodiment of the sole assembly 1 . Besides comprising a midsole 2 and a first tensile layer 3 and a second tensile layer 4, the sole assembly 1 illustrated in figure 3 also comprises a third tensile layer 5 and a fourth tensile layer 6 arranged in the vertical direction V between the first tensile layer 3 and the second tensile layer 4. The sole assembly 1 further comprises a midsole plate 8 arranged within the midsole 2.

List of designations

1 Sole assembly 6 Fourth tensile layer

2 Midsole 7 Outsole

2U Upper surface of the midsole 8 Midsole plate

2L Lower surface of the midsole L longitudinal direction

3 First tensile layer V vertical direction

3U Upper face of the first tensile layer T transversal direction

4 Second tensile layer HA Heel area

4U Upper face of the second tensile MA midfoot area layer

FA forefoot area

5 Third tensile layer

Claims

1. Sole assembly (1) extending in a longitudinal direction (L) from a heel area (HA) across a midfoot area (MA) to a forefoot area (FA) and comprising:

• a midsole (2) extending in a vertical direction (V) from an upper surface (2U) configured to face an upper to a lower surface (2L) configured to face an outsole (7);

• one or more tensile layers (3, 4, 5) connected to the midsole (2) and extending along the longitudinal direction (L) and/or along a transversal direction (T) orthogonal to the longitudinal direction.

2. Sole assembly (1) according to claim 1 , wherein the one or more tensile layers (3, 4, 5) have a tensile strength in longitudinal direction that is at least 10%, preferably at least 30%, more preferably at least 50%, even more preferably at least 100%, higher compared to a tensile strength in longitudinal direction of the midsole (2); and/or wherein the one or more tensile layers (3, 4, 5) have a tensile strength in transversal direction that is at least 10%, preferably at least 30%, more preferably at least 50%, even more preferably at least 100%, higher compared to a tensile strength in transversal direction of the midsole (2).

3. Sole assembly (1) according to any one of the previous claims, wherein the one or more tensile layers (3, 4, 5) are compressible in longitudinal direction and/or in transversal direction.

4. Sole assembly (1) according to any one of the previous claims, wherein each of the one or more tensile layers (3, 4, 5) has a layer thickness of less than 5 mm, preferably less than 1 mm, more preferably less than 0.5 mm.

5. Sole assembly (1) according to any one of the previous claims, wherein at least one of the one or more tensile layers (3, 4, 5) is materially bonded to the midsole (2), preferably by lamination, co-molding, welding, sewing or through an adhesive.

6. Sole assembly (1) according to any one of the previous claims, wherein each of the one or more tensile layers (3, 4, 5) comprises, or consists of, a plurality of tensile filaments.

7. Sole assembly (1) according to claim 6, wherein each of the one or more tensile layers (3, 4, 5) is a tensile fabric formed from the plurality of tensile filaments.

8. Sole assembly (1) according to any one of the previous claims, wherein each of the one or more tensile layers (3, 4, 5) has an extension in the longitudinal direction (L) of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm; and/or each of the one or more tensile layers (3, 4, 5) has an extension in the transversal direction (T) of at least 1 cm, preferably at least 2 cm, more preferably at least 3 cm.

9. Sole assembly (1) according to any one of the previous claims, wherein the one or more tensile layers (3, 4, 5) are made of polyethylene with ultra-high-molecular-weight (PE-UHMW), polyamide, carbon fiber, polysulfone, polyether sulfone, polyester, or a mixture or copolymer thereof.

10. Sole assembly (1) according to any one of the previous claims, wherein the one or more tensile layers (3, 4, 5) are arranged in one or more of the followings areas:

• the heel area (HA) of the sole assembly (1); the midfoot area (MA) of the sole assembly (1); and/or the forefoot area (FA) of the sole assembly (1).

11. Sole assembly (1) according to any one of the previous claims, wherein a forefoot portion of at least a first tensile layer (3), and optionally also a midfoot portion of the first tensile layer (3), are each arranged within 15 mm, preferably within 10 mm, more preferably within 6 mm, even more preferably within 3 mm, of the lower surface (2L) of the midsole (2).

12. Sole assembly (1) according to any one of the previous claims, wherein at least in the forefoot area (FA) and optionally also in the midfoot area (MA) and/or in the heel area (HA), a first tensile layer (3) extends parallel to the outer surface of the midsole (2).

13. Sole assembly (1) according to any one of the previous claims, further comprising a second tensile layer (4) extending along the longitudinal direction (L) and/or along the transversal direction (T), wherein at least a portion of the second tensile layer (4) is arranged in the vertical direction (V) closer to the upper surface (2U) of the midsole (2) than to the lower surface (2L) of the midsole (2).

14. Sole assembly (1) according to any one of the previous claims, wherein at least in the forefoot area (FA) and optionally also in the midfoot area (MA) and/or in the heel area (HA), at least one of the one or more tensile layers (3, 4, 5) has an upper face (3U, 4U, 5U) that is concave in a longitudinal cross section parallel to the vertical direction (V) and parallel to the longitudinal direction (L).

15. Sole assembly (1) according to any one of the previous claims, wherein at least in the forefoot area (FA) and optionally also in the midfoot area (MA) and/or in the heel area (HA), at least one of the one or more tensile layers (3, 4, 5) has an upper face (3U, 4U, 5U) that is either straight or concave in a transversal cross section parallel to the vertical direction (V) and orthogonal to the longitudinal direction (L).

16. Method of manufacturing a sole assembly (1) comprising: • Providing a midsole (2) extending in a vertical direction (V) from an upper surface (2U) configured to face an upper to a lower surface (2L) configured to face an outsole (7);

• Connecting to the midsole (2) one or more tensile layers (3, 4, 5) such that they extend along the longitudinal direction (L) and/or along the transversal direction (T).

17. Shoe comprising a sole assembly (1) according to any one of claims 1-15 and an upper.

18. Use of a sole assembly (1) according to any one of claims 1-15, for manufacturing a shoe.