Method for producing a shoe sole element and shoe sole element

Abstract

Disclosed herein is a single element (1) comprising one or more tubular channel structures (3, 4) in which a cured fiber composite comprising fibers and a resin is introduced into the one or more tubular channel structures (3, 4), and a method for producing the single element is also provided.

Description

[Background technology]

[0001] [Field of Disclosure]

[0002] The present invention relates to the field of shoe technology, in particular running shoe technology, and relates to a method for producing a sole element and to a sole element. [Background, Prior Art]

[0003] In recent years, energy recovery systems have emerged as an important element in running shoes. The most prominent system is a rigid plate, which is typically elastic and therefore often incompressible. For example, a continuous carbon fiber composite plate can be incorporated into the sole structure of a running shoe. Such a plate typically extends over the entire metatarsal joint area and is therefore preferably located at least in the forefoot and midfoot regions of the sole structure. During stride-on and the subsequent foot roll-off, the rigid plate flexes, temporarily storing energy due to its elastic behavior. During push-off, the flexed elastic plate returns to its original, relatively flat shape, supporting the runner's push-off motion. Ultimately, this results in improvements in runner performance, e.g., in terms of running speed and fatigue delay.

[0004] Most commonly, a separate rigid plate is provided, which essentially extends over the entire forefoot and midfoot area, and sometimes even the heel area. Such a plate is usually a one-piece plate made of a suitable material, such as a fiber composite material. A drawback of such a continuous plate is that it increases the overall weight of the sole and, therefore, the running shoe. However, even a small increase in weight can have a significant impact on running performance and competitiveness, especially in high-performance and professional sports.

[0005] Certain known energy recovery systems use notched plates to minimize the weight of the system, or use only one or more independent rigid rod elements extending through the midfoot and forefoot regions. However, a common problem with the latter systems is the need to fasten the individual rods to other elements of the sole structure and their relatively cumbersome production. Furthermore, such isolated rods often result in poor force transmission.

[0006] Another common problem with known energy recovery systems is limited design freedom due to manufacturing constraints. For example, if a particular energy recovery system is to be tailored to an individual's gait or foot anatomy, most systems are traditionally manufactured using injection molding, which necessitates custom mold adjustments for each individual, creating manufacturing challenges. Additionally, many known energy recovery systems are manufactured in a way that does not allow them to be easily and quickly adapted to an individual's specific requirements.

[0007] Disclosure Overview

[0008] Therefore, the general object of the present invention is to completely or partially overcome the problems of the prior art in the field of shoe technology, in particular in shoe energy recovery systems, and to improve the state of the art. In advantageous embodiments, a method for producing a sole element is provided that can be easily and efficiently adapted to the specific requirements of a runner. In further advantageous embodiments, a method for producing a sole element is provided that allows for more efficient production and / or increased design freedom of the produced sole element. In further advantageous embodiments, a sole element is provided that is able to return energy to the runner and that is lighter in weight than known systems. In further advantageous embodiments, a sole element is provided that generally has a better energy return effect than known systems.

[0009] This general object is achieved by what is stated in the independent claims. Further advantageous embodiments follow from the dependent claims and the entire disclosure. In a first aspect, the present invention relates in particular to a method for producing a reinforced sole element, said method comprising the following steps: Providing a blank sole element with one or more, in particular a plurality of, tubular channel structures. b. Introducing, preferably injecting, a fiber composite into one or more tubular channel structures, i.e. into the channels formed by the tubular channel structures, the fiber composite comprising or consisting of fibers and a resin, in particular a flowable resin. c. Curing the introduced, preferably injected, fiber composite to obtain a sole element, in particular a reinforced sole element.

[0010] The method according to the present invention provides a fast and efficient way to produce sole elements. Sole elements produced in this manner can be considered reinforced sole elements. Reinforced sole elements are more reinforced than sole elements that do not have a tubular channel structure defining channels filled with a fiber composite. The tubular channel structure can be easily arranged in a desired manner and reinforced by inserting a fiber composite. By arranging the tubular channel structure in a desired manner, it is possible to predetermine which areas of the sole element will be reinforced with the cured fiber composite. In contrast to continuous plate elements, reinforcement occurs only in predeterminable areas, thereby reducing the weight of the entire sole and, therefore, the shoe. Furthermore, the tubular channel structure ensures that the cured fiber composite reinforcement is held in place and does not move even during extended use.

[0011] "Blank sole element" refers to a sole element that contains air (eg, atmospheric pressure of 1 atmosphere) within the tubular channel structure and has not yet had a fiber composite introduced therein.

[0012] In some embodiments, the blank sole element provided in step a further comprises a base body, with one or more tubular channel structures extending along the base body.

[0013] By "extending along the base body" it is meant that the tubular channel structure can be disposed within, adjacent to, above and / or below the base body, however typically the tubular channel structure is in direct contact with the base body.

[0014] In some embodiments, the blank sole element provided in step a further comprises a blank base body, with one or more tubular channel structures extending along the blank base body. The blank base body is converted into the base body before or after step b. It is understood that such conversion requires physical and / or chemical modification of the blank base body. For example, the blank base body can be foamed into the base body. "Extending along the blank base body" encompasses that the tubular channel structures can be located within, adjacent to, above, and / or below the blank base body. However, typically, the tubular channel structures are in direct contact with the blank base body.

[0015] It is understood that one or more tubular channel structures, either alone or in conjunction with the base body, define a corresponding channel. Each channel can have a channel volume. When a tubular channel structure alone defines a channel, the channel wall is formed solely by the tubular channel structure. In such embodiments, the tubular channel structure defines the periphery, except for any channel openings. The channel openings in this context generally refer to distal channel openings that define the beginning and / or end of the channel.

[0016] When the tubular channel structure defines a channel together with the base body, the channel is bounded by the channel structure and the base body, and thus the channel walls are formed by the tubular channel structure and the base body. In such embodiments, the tubular channel structure and the base body still bound the periphery, except for any channel openings. For example, the tubular channel structure may have a U-shaped or V-shaped cross-section, which, when combined with the base body, results in a substantially rectangular or triangular channel cross-section. Thus, one or more tubular channel structures, either alone or together with the base body, define a cavity into which a fiber composite can be introduced.

[0017] Typically, each tubular channel structure, alone or in combination with a base body, has two channel openings, i.e., a channel inlet and a channel outlet, for introducing a fiber composite. Each tubular channel structure typically has at least one, two, three, or four channel walls, which, alone or in combination with the base body, define a corresponding channel. The channel walls of the tubular channel structure typically have a wall thickness t.

[0018] As used herein, a flowable resin is a resin having a viscosity selected to allow it to be poured into one or more tubular channel structures, e.g., a resin that is liquid in its uncured state and can be solidified, e.g., by heating and subsequent cooling, chemical reaction, and / or irradiation. In particular, the flowable resin may be a molten resin.

[0019] Curing the fiber composite can include, for example, curing the resin. In particular, the resin is solidified and / or hardened during curing. In some embodiments, curing can include cooling the resin.

[0020] In some embodiments, curing involves heating the introduced fiber composite to or above the cure temperature of the resin. In certain embodiments, curing can involve subsequent cooling of the heated resin. The cure temperature of the resin is the minimum temperature required for cure to occur. In some embodiments, curing can involve irradiating the introduced fiber composite with light of an appropriate wavelength.

[0021] In some embodiments, providing a blank sole element in step a includes sub-step a1: producing one or more tubular channel structures by additive manufacturing, blow molding or extrusion.

[0022] In some embodiments, the base body or blank base body is also produced by additive manufacturing, blow molding, or extrusion. In certain embodiments, the one or more tubular channel structures and the base body or blank base body are integrally formed, i.e., integrally molded. In other embodiments, the one or more tubular channel structures and the base body or blank base body are produced separately and then connected by a suitable connection method, such as welding or adhesive bonding. The base body or blank base body may also define a recess into which the tubular channel structure can be placed, particularly by shape-locking and / or mechanical locking. The tubular channel structure is produced before step b, i.e., the injection of the fiber composite, while the base body or blank base body may be produced before or after step b. However, typically, in step b, the fiber composite is injected into a channel, preferably bounded by channel walls, except for at least two channel openings. Therefore, the channel is preferably not a groove open to the environment along its extension direction.

[0023] In a preferred embodiment, one or more tubular channel structures and optionally the base body or blank base body are produced by additive manufacturing. Additive manufacturing can include any suitable 3D printing technology, such as SLS, FDM, etc. Additive manufacturing can be used to easily customize the sole element produced to meet specific individual requirements. For example, the arrangement, number, size, shape, and other characteristics of the tubular channel structures can be easily adjusted using additive manufacturing. Combined with the injection and curing of a fiber composite, this allows for significant design freedom while maintaining an efficient production process. Combining steps a-c of the method of the present invention with additive manufacturing can rapidly provide reinforcing and stiffening elements in shapes and arrangements within the sole element that were previously difficult or nearly impossible to achieve.

[0024] In some embodiments, one or more tubular channel structures are provided to extend at least partially along the length of the blank and produced sole elements and / or to extend from the midfoot region to the forefoot region. In preferred embodiments, one or more tubular channel structures are positioned to extend from the heel region through the midfoot region to the forefoot region of the blank and produced sole elements.

[0025] The directional designations used in this specification are understood as follows: the longitudinal direction L of the sole element is described by the axis from the heel region or the respective heel edge to the forefoot region or the respective sole element tip, and extends along the longitudinal axis of the sole element. The transverse direction T of the sole element extends transversely to the longitudinal axis and is substantially parallel to the ground in the operating state. The transverse direction therefore runs along the transverse axis of the sole element. In the context of the present invention, the vertical direction V is oriented in the direction of the wearer's foot in the operating state and runs along the vertical axis of the sole element. The longitudinal, vertical and transverse directions may all be perpendicular to one another. The lateral side of the sole element is the outer periphery of the sole element from the heel edge to the tip of the sole element, which rests on the outer instep of the wearer's foot in the worn state. The medial side of the sole element is the inner periphery of the sole element from the heel edge to the tip of the sole element, and is positioned opposite the lateral side. Thus, in a pair of shoes, the medial sides of the two shoes face each other, and the lateral sides face outward. The sole element is further divided longitudinally into a forefoot region, a midfoot region, and optionally a heel region, where the heel region, if present, is disposed between the forefoot and heel regions.

[0026] In some embodiments, providing the blank sole element includes performing a gait analysis and / or a foot analysis of the individual and producing the blank sole element in response to the performed gait analysis and / or foot analysis. The blank sole element is provided or produced based on the gait analysis and / or foot analysis. The foot analysis may include, for example, a 3D scan of the individual's foot. The gait analysis may include, for example, gait monitoring with a high-speed camera or the use of a pressure plate with force sensors. Such an embodiment may be preferably combined with an embodiment in which step a includes sub-step a1. Thus, it is possible to perform a gait and / or foot analysis of the individual and produce the blank sole element based on the analysis results, for example, by additive manufacturing, blow molding, or extrusion.

[0027] The fibres of the fibre composite may be selected from one or more of carbon fibres, basalt fibres, aramid fibres, glass fibres, linen fibres and hemp fibres.

[0028] In some embodiments, the fibers may be endless fibers and / or fiber bundles, preferably fiber bundles of endless fibers.

[0029] In some embodiments, the blank sole element provided in step a comprises a plurality of tubular channel structures forming a channel structure network. The channel structure network comprises at least two openings providing fluid communication between the interior of the plurality of tubular channel structures and the environment outside the blank sole element. Typically, two openings for each group of fluidly communicating tubular channel structures are sufficient for introducing the fiber composite. In some embodiments, most or all of the tubular channel structures of the channel structure network are in fluid communication with each other.

[0030] In some embodiments, the blank sole element provided in step a comprises a plurality of tubular channel structures, the plurality of tubular channel structures comprising a plurality of main channel structures and one or more connecting channel structures, the one or more connecting channel structures fluidly connecting two or more main channel structures to one another.

[0031] In some embodiments, in step b, the fibers and resin are introduced, in particular injected, simultaneously, which has the advantage that the fibers are efficiently carried into the channels by the resin.

[0032] In some embodiments, at least one of the one or more tubular channel structures comprises a bifurcation where the at least one tubular channel structure branches into two or more sub-channel structures. The bifurcation may be, for example, forked.

[0033] In some embodiments, the fiber composite is injected so that the tubular channel structure is filled with more than 90%, particularly more than 95%, more particularly more than 98%, and even more particularly 100% of its channel volume. It is understood that channel volume here refers to the volume of the channel before the fiber composite is introduced. The channel volume is typically defined by the channel walls. The tubular channel structure is filled with the fiber composite to these extents.

[0034] In some embodiments, one or more tubular channel structures may have a rectangular (rectangular, trapezoidal, triangular, etc.) or circular (oval, circular, etc.) cross-section. Unless otherwise specified, cross-section preferably refers to a plane perpendicular to the direction of channel extension, i.e., the direction in which the tubular channel structure extends.

[0035] Additionally, in some embodiments, the tubular channel structure alone or one or more channels formed with the base body may have an angular cross-section, such as rectangular, trapezoidal, triangular, or circular, particular ellipsoidal, or circular cross-section. Unless otherwise specified, cross-section refers to a plane perpendicular to the direction of channel extension.

[0036] In some embodiments, at least one tubular channel structure and / or at least one channel defined by the tubular channel structure alone or in combination with the base body may vary in cross-section along the channel, i.e., along a particular channel, for example, a corresponding channel may have a rectangular cross-section in the midfoot region and a circular cross-section in the forefoot region, or vice versa.

[0037] In some embodiments, each channel defined by the tubular channel structure alone or in combination with the base body is 2.5 mm 2 ~15.0mm 2 , especially 4.0mm 2 ~10.0mm 2 "Open area" is the surface area defined by the tubular channel structure and any base body, i.e., channel walls, but does not include any fiber composite within the tubular channel structure or within the channels.

[0038] In certain embodiments, the cross-sectional open area defined by the at least one tubular channel structure and any base body may vary along the channel. In some embodiments, the channel height defined by the tubular channel structure alone or in combination with the base body is between 1.2 mm and 10.0 mm, particularly between 1.7 mm and 7.5 mm. The channel height is the extension of the channel in the vertical direction.

[0039] In some embodiments, the ratio of channel height to base body height (ie extension along the vertical direction) is between 5:1 and 1:1, in particular between 21:5 and 9:8.

[0040] In some embodiments, the width of the channel defined by the tubular channel structure is between 1.2 mm and 20.0 mm, particularly between 1.7 mm and 7.5 mm. The width is the extension of the channel in a transverse direction, perpendicular to the direction in which the channel extends.

[0041] In some embodiments, the ratio of the channel width to the overall width (extension in the transverse direction) of the sole element is between 1:1 and 85:1, in particular between 3:1 and 21:1.

[0042] The height and width of a channel typically lie in a cross-sectional plane perpendicular to the direction of elongation of the corresponding channel and / or tubular channel structure.

[0043] In some embodiments, the height and / or width of the channel defined by the at least one tubular channel structure and any base body may vary along the channel.

[0044] In some embodiments, the blank sole element and the produced sole element comprise one, two, three, four, five, or six independent tubular channel structures. The independent tubular channel structures are not in fluid communication with one another. In certain embodiments, the blank sole element and the produced sole element comprise only one, two, three, four, five, or six independent tubular channel structures.

[0045] In some embodiments, the base body comprises a plurality of through holes, i.e., holes that extend through the base body, and the sum of the open areas defined by the holes is between 0% and 90%, particularly between >0% and 90%, and more particularly between 10% and 75% of the total surface area of ​​the base body.

[0046] The one or more tubular channel structures and the base body may be made of a material selected from the following: thermoplastic polyurethane (TPU), thermoplastic elastomer, polyamide, polyether block amide, ethylene vinyl acetate, polyvinylidene fluoride, polyolefin, and polyester.

[0047] The one or more tubular channel structures and the base body may be made of the same material or different materials.

[0048] In some embodiments, the sole element may be a sole plate. In certain embodiments, the sole plate may be a rigid sole plate. For example, the sole plate may be a resilient, incompressible sole plate.

[0049] In some embodiments, the sole plate extends from at least the midfoot region to the forefoot region and has a tip. The tip typically coincides with the tip of the shoe in which the sole plate is used. Thus, when worn, the tip is longitudinally positioned in front of the wearer's toes. In certain embodiments, the sole plate extends from the heel region through the midfoot region to the forefoot region. In such embodiments, the sole plate has a heel edge. The heel edge is the portion furthest from the tip along the longitudinal direction. If the sole plate extends from the midsole region to the forefoot region (but does not extend to the heel region), the sole plate has a midfoot edge. In this case, the midfoot edge is the portion furthest from the tip along the longitudinal direction.

[0050] In some embodiments, the resulting sole element, particularly the sole plate, has a flexural modulus of at least 12000 N / mm as measured by Test Method 1. 2 , in particular at least 15000 N / mm 2 , more specifically at least 20000N / mm 2 In some embodiments, the sole element, particularly the sole plate, has a flexural modulus of up to 70,000 N / mm as measured by Test Method 1. 2 , especially up to 60000N / mm 2 , more specifically up to 55000N / mm 2 Such a flexural modulus provides a stable stance and efficient push-off.

[0051] According to test method 1, a three-point bending test is performed (for the three-point bending test, https: / / en.wikipedia.org / wiki / Three-point_flexural_testand DIN EN ISO 178:2019). For this purpose, the sole element, in particular the sole plate, is positioned with the base layer facing down on two support pins that extend across the entire transverse direction of the sole element. The sole element, in particular the sole plate, used is typically a US size 10 sole plate and is 262 mm long. The two support pins are spaced 160 mm apart from each other. Each support pin has a transverse width of 70 mm (extension along the transverse direction of the sole plate during measurement) and a rounded edge with a radius of curvature of 25 mm, which supports the sole element, in particular the sole plate. A load pin is then placed on the top layer at 70% of the total length of the sole element, in particular the sole plate, measured from the heel edge to the tip. The load pin has a transverse width of 70 mm (extension along the transverse direction of the sole plate during measurement) and a semi-cylindrical rounded edge with a radius of curvature of 25 mm, which presses against the sole element, in particular the sole plate. The load pin is located longitudinally between two support pins. The front support pin, i.e., the support pin closer to the tip of the sole element, in particular the sole plate, is spaced longitudinally 80 mm from the load pin (measured from the pole of the pin), and the rear support pin, i.e., the support pin located closer to the heel edge or midfoot edge of the sole element, in particular the sole plate, is spaced longitudinally 80 mm from the load pin (measured from the pole of the pin). All three pins located on the longitudinal centerline of the sole element, in particular the sole plate, have essentially the same extension in the transverse direction, i.e., to the outer periphery and to the inner periphery of each pin. Next, a preload of 10 N (F0) is applied to the load pin when testing the sole element, particularly the sole plate, or 25 N (F0) when testing the entire shoe with upper. The load pin is then loaded stepwise (5 times) with bending forces to measure the force (F1) required to deflect the sole element, particularly the sole plate, vertically by 15 mm (test speed: 300 mm / min). The flexural modulus can be calculated using the formula E = l3vΔF / (4DLba3), where ΔF is the difference in Newtons between the end (F1) and start (F0) of the measurement, lv is the support span width (mm), DL is the bending distance between F1 and F0 (mm), b is the sample width at the load pin (mm), and a is the sample thickness at the load pin (mm). In embodiments of sole elements, particularly sole plates, including multiple tubular channel structures, the tubular channel structures are preferably spaced apart from one another in a generally transverse direction. Preferably, at least two tubular channel structures are spaced apart from one another in a transverse direction. In certain embodiments, at least a portion of the base body may be disposed between the spaced-apart tubular channel structures. In some embodiments, one or more tubular channel structures may be disposed between each two portions of the base body.

[0052] In some embodiments of the sole plate, the base body and the one or more tubular channel structures may be made of the same material, or may be made of different materials.

[0053] In another embodiment, the sole element may be a midsole. The tubular channel structure and the base body may be integrally formed. In some embodiments of the sole element that is a midsole, the base body and / or the tubular channel structure may be made of a polymer foam.

[0054] In another embodiment, the one or more tubular channel structures may be separate from the base body. For example, the base body may be made of a polymer foam. The tubular channel structures may be made of the same or different materials, particularly polymeric materials, but preferably non-foamed. The polymer foam structure and the one or more tubular channel structures are not integrally formed. In some embodiments, the polymer foam structure may at least partially or completely surround the one or more tubular channel structures. It should be understood, however, that this excludes the openings of the tubular channel structures. For example, the base body may be a polymer foam element defining grooves or recesses into which the tubular channel structures can be positioned with shape and / or mechanical locking.

[0055] In a specific embodiment of a sole element that is a midsole, step a includes knitting a tubular channel structure and a blank base body. The blank base body is converted into a base body, i.e., a finished base body, in subsequent substeps. This base body and the entire blank sole element are used in step b. For example, the blank base body and one or more tubular channel structures can be manufactured together or separately. The blank base body may be manufactured to be foamable. For example, a foaming agent may be contained, preferably only in the blank base body. In a subsequent step, the blank base body can be foamed to obtain a polymer foam structure. For example, as described above, the blank base body and one or more tubular channel structures may be formed by additive manufacturing. In another embodiment, step a includes only the formation of the tubular channel structure, particularly from a foamed polymer material. Then, step b is performed, i.e., a fiber composite is injected into the tubular channel structure to fill the channels defined by the tubular channel structure. The tubular channel structure is then connected to the base body, e.g., a polymer foam element, e.g., before or after curing.

[0056] In a second aspect, the present invention relates to a sole element, in particular a sole element obtainable by a method as described in any of the embodiments herein with respect to the first aspect of the invention.

[0057] The embodiments and features described herein with respect to any embodiment of the method also preferably apply to the embodiment of the sole element of the second aspect, and conversely, the embodiments and features described herein with respect to any embodiment of the sole element of the second aspect also preferably apply to the embodiment of the method of the first aspect.

[0058] The sole element comprises one or more tubular channel structures. Furthermore, a cured fiber composite comprising or consisting of fibers and resin is introduced, preferably injected, into the one or more tubular channel structures, i.e., the channels formed by them. The cured fiber composite is thus disposed within the one or more tubular channel structures, i.e., the channels. The sole element is preferably a reinforced sole element.

[0059] In some embodiments, the sole element further comprises a base body, with one or more tubular channel structures extending along the base body.

[0060] In some embodiments, one or more tubular channel structures protrude from the base body, preferably perpendicularly from the base body.

[0061] In some embodiments, the one or more tubular channel structures have at least one, two, three, or four channel walls, each having a wall thickness t.

[0062] The channel walls, alone or in combination with the base body, define a channel having a maximum channel width, w. The maximum channel width is perpendicular to the direction of extension of the channel and defines the maximum distance between opposing channel wall sections. For a circular cross section, the maximum channel width is the channel diameter.

[0063] In a particular embodiment, the ratio t:w is between 1:150 and 1:3, in particular between 1:75 and 2:7, and more particularly between 1:50 and 1:4.

[0064] In some embodiments, the tubular channel structures, ie, channels, are filled with cured fiber composite to greater than 90%, particularly greater than 95%, more particularly greater than 98%, and more particularly 100% of their channel volume.

[0065] In some embodiments, the resin of the cured fiber composite is directly material-bonded to the one or more tubular channel structures and any base body. Direct material bonding means that no additional adhesive is used. For example, uncured fiber composite can be inserted into the one or more tubular channel structures, i.e., into the channels defined by them. Curing also includes forming a direct material bond between the resin and the one or more tubular channel structures and any base body. This holds the fiber composite in place during long-term and extensive use of the shoe. It should be understood that even with a direct material bond, the tubular channel structures and the cured fiber composite are not integral, i.e., distinct from one another. For example, the one or more tubular channel structures and the cured fiber composite, particularly the resin of the fiber composite, may be different materials and / or have different physical properties, such as hardness or density. Preferably, the resin is directly material-bonded to at least 90%, particularly 95%, and more particularly 99% or 100% of the length of each tubular channel structure of the one or more tubular channel structures and any base body.

[0066] In some embodiments, the sole element comprises a plurality of tubular channel structures, which in certain embodiments include a main channel structure and one or more connecting channel structures that connect two or more main channel structures to one another. The main channel structure and the connecting channel structures, for example, define a channel structure network. By connected channels, it is understood that a cured fiber composite disposed within the channels extends continuously through the connected channels.

[0067] In some embodiments, the sole element comprises a plurality of tubular channel structures forming a channel structure network, at least some or all of the tubular channel structures of the channel structure network being connected to one another.

[0068] As mentioned above in relation to the first aspect of the invention, the sole element may be a sole plate, in particular a stiffening sole plate, i.e. a sole plate configured to stiffen the sole of a shoe, or the sole element may be a midsole.

[0069] In embodiments where the sole element is a sole plate, the weight of the plate element is preferably between 10 g and 40 g, especially between 15 g and 35 g. In some embodiments, the average density of the sole plate is 0.8 g / cm 3 ~3g / cm 3 , especially 0.9 g / cm 3 ~2.5g / cm 3 is.

[0070] In some embodiments, the surface area of ​​the base body through which the one or more tubular channel structures extend is 3% to 85%, particularly 5% to 60%, of the total surface area of ​​the sole element. The total surface area is defined as the surface area of ​​one side of the sole element. The sole element has a top side and a bottom side, oriented vertically. In a worn or active state, the bottom side faces the ground, and the top side faces the wearer's foot. Therefore, the total surface area generally refers to the surface area of ​​the side through which the one or more tubular channel structures extend.

[0071] In some embodiments, the sole elements, particularly the sole plate, have a vertical bend in the forefoot or midfoot region, in other words, the forefoot region may be angled relative to the midfoot region and optional heel region.

[0072] According to a third aspect, the present invention relates to a shoe comprising a sole element according to any of the embodiments described herein, particularly with respect to the second aspect. In some embodiments, the shoe comprises a sole structure including such a sole element and an upper connected to the sole structure. The upper and sole structure typically define a foot-receiving compartment. [Brief explanation of the drawings]

[0073] The present invention will be more fully understood from the following detailed description and the accompanying drawings, which do not limit the invention as set forth in the appended claims. [Figure 1] FIG. 1 is a perspective view of a sole element 1 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a sole element according to another embodiment of the present invention, taken in a plane perpendicular to the longitudinal direction L and defined by the transverse direction T and the vertical direction V. [Figure 3] FIG. 3 is a top view of a sole element according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram of a sole element according to another embodiment of the present invention. [Figure 5] FIG. 5 is a schematic diagram of a sole element according to another embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram of a sole element that is a midsole according to another embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of a sole element according to another embodiment of the present invention, taken in a plane perpendicular to the longitudinal direction L and defined by the transverse direction T and the vertical direction V. [Figure 8] FIG. 8 is a schematic diagram of a sole element that is a midsole according to another embodiment of the present invention. [Figure 9] FIG. 9 is a schematic diagram of a sole element that is a midsole according to another embodiment of the present invention. [Figure 10] FIG. 10 shows the results of a flexural modulus test of the sole plate according to the present invention and a comparison with a standard sole plate.

[0074] Illustrative Embodiments

[0075] FIG. 1 shows a blank sole element 1' from which a sole element 1, a sole plate, can be produced. The blank sole element 1' comprises a base body 2 and two tubular channel structures 3 and 4 extending substantially parallel along the base body 2 on the bottom side of the sole element 1. The tubular channel structures 3 and 4 extend along a longitudinal direction L and have a rectangular shape in a cross section perpendicular to the longitudinal direction L (i.e., the V-T plane). Each of the tubular channel structures 3 and 4 has two openings 31, 32, and 42 (the second opening of tubular channel 4 is not visible in this perspective view) located at opposite ends of the corresponding tubular channel structure. During production, a fiber composite is introduced into the corresponding tubular channel structure through one of the openings, e.g., opening 31, and then transported to the second opening 32. The fiber composite comprises a resin and fibers. When the resin is in a fluid or liquid state, it transports the fibers into the channels defined by the tubular channel structures 3, uniformly distributing the composite. The blank sole element 1' shown extends from the heel region through the midfoot region to the forefoot region.

[0076] 2 shows a cross-sectional view of a sole element 1 according to another embodiment. The cross-section is perpendicular to the extension direction of the corresponding channel, i.e., in this embodiment, the longitudinal direction L, and lies in a plane defined by the vertical direction V and the transverse direction T. The sole element 1 comprises a base body 2 and two tubular channel structures 3 and 4. It can be seen that a cured fiber composite 5 has been introduced into the tubular channel structures 3 and 4, completely filling the corresponding channels with the cured fiber composite 5. Each channel structure has a channel wall with a wall thickness t and defines a channel with a maximum channel width w.

[0077] 3 shows another embodiment of sole element 1 in which base body 2 has a plurality of through openings, thereby reducing the overall weight of the sole element. The desired stiffening effect is achieved primarily by the stiffened fiber composite inserted into tubular channel structures 3 and 4, so that a relatively large open area defined by the through openings can be achieved without compromising the stiffening effect.

[0078] 4 shows another embodiment of a sole element 1, in which the base body 2 is provided with and defines a plurality of through openings. Furthermore, the sole element comprises two tubular channel structures 3 and 4 extending longitudinally from the heel region to the tip of the sole element.

[0079] 5 shows a different embodiment of sole element 1 according to the present invention. In this embodiment, the sole element consists essentially of a single tubular channel structure. The channel opening is located on the rear side and is not visible in this view. In this embodiment or any other embodiment described herein, the tubular channel structure may delimit the periphery of sole element 1.

[0080] Figure 6 shows another embodiment of a sole element 1. Unlike the embodiments shown in Figures 2, 3 or 4, the sole element 1 is not a sole plate but a midsole. This sole element comprises a base body 2 made of polymer foam. The base body 2 defines two grooves in which tubular channel structures 3 and 4 are arranged. It can be seen that both channels defined by the tubular channel structures 3 and 4 are filled with a fiber composite.

[0081] Figure 7 shows another sole element 1 according to the invention. In this embodiment, a cross-sectional view is shown, showing that sole element 1 comprises two tubular channel structures. As also shown, for example, in Figure 9 below, each tubular channel structure branches into two sub-channel structures, namely, sub-channel structures 33 and 34, and sub-channel structures 43 and 44. Such an embodiment may be made, for example, from a midsole in which one or more tubular channel structures define hollow channels into which a fiber composite is injected.

[0082] 8 shows another embodiment of the sole element 1 in transverse and longitudinal cross-section. In this embodiment, the sole element 1 comprises only a single tubular channel structure 3 extending along the base body 2. Both openings 31 and 32 of the tubular channel structure 3 are located at the heel edge in the heel region. In the forefoot region, in this embodiment or any other embodiment described herein, at least one tubular channel structure, i.e., in this embodiment, tubular channel structure 3, may form a meandering structure.

[0083] Figure 9 shows another embodiment having two tubular channel structures 3 and 4. Both tubular channel structures comprise a bifurcation, e.g., bifurcation 42, where the corresponding tubular channel branches into multiple sub-channel structures, e.g., sub-channel structures 43 and 44 (only two are shown for clarity).

[0084] FIG. 10 shows measurements of the flexural modulus and energy return of a sole plate according to the present invention (a) and d)) (such as that shown in FIG. 3) compared to a continuous plate element according to the prior art (a continuous plate that essentially extends throughout the forefoot, midfoot, and heel regions). Measurements a) and b) are made in the forefoot / midfoot region according to Test Method 1 described herein. Measurements c) and d) are comparative measurements in the heel region. The flexural modulus of the continuous plate in the forefoot / midfoot region is [24.4 N / mm 2 , see b)], whereas for the sole element according to the invention [16.7 N / mm 2 , see a)], but the energy return WFrem / WFapply is much higher for the sole element according to the invention [72%, see a)] than for the continuous sole element [54%, see b)]. Since this energy return is most important in the forefoot / midfoot regions where the sole plate flexes during running, Figure 6 shows that better energy return can be achieved with the method and sole element according to the invention. Furthermore, the energy return can be easily adjusted by changing the size, dimensions, shape, position and / or number of the tubular channel structures. [Explanation of symbols]

[0085] 1...sole elements, 1'...blank sole element, 2...base body, 2'...Blank base body, 3...tubular channel structure, 31...opening, 32...opening, 33...Subchannel structure, 34...Subchannel structure, 4...tubular channel structure, 41...opening, 42...Bifurcation, 43...Subchannel structure, 44...Subchannel structure, 5...Fiber composites, L...Longitudinal direction, T...transverse direction, V…Vertical direction.

Claims

1. A method for producing a sole element (1) for a shoe, comprising: a. Providing a blank sole element (1') with one or more tubular channel structures (3, 4); b. introducing, preferably injecting, a fiber composite (5) comprising fibers and a resin into one or more tubular channel structures (3, 4); c. Curing the introduced fiber composite (5); A method comprising:

2. 2. The method of claim 1, wherein the blank sole element (1') provided in step a further comprises a base body (2), and the one or more tubular channel structures (3, 4) extend along the base body (2).

3. 2. The method according to claim 1, wherein the blank sole element (1') provided in step a) further comprises a blank base body, the one or more tubular channel structures (3, 4) extending along the blank base body, and the blank base body is converted into a base body (2) before or after step b), in particular by foaming.

4. The method according to any one of claims 1 to 3, wherein step a) comprises producing the one or more tubular channel structures (3, 4) and optionally the base body (2) by additive manufacturing, blow molding or extrusion.

5. The method according to any one of claims 1 to 4, wherein the one or more tubular channel structures (3, 4) are provided so as to extend at least partially along the longitudinal direction (L) of the sole element (1).

6. The method according to any one of claims 1 to 5, wherein step a) comprises the steps of performing an individual gait and / or foot analysis and producing the sole element (1) according to said gait and / or foot analysis.

7. 7. The method according to any one of claims 1 to 6, wherein the fibres are endless fibres and / or the fibres are selected from one or more of carbon fibres, basalt fibres, aramid fibres, glass fibres, linen fibres and hemp fibres.

8. 8. The method according to any one of claims 1 to 7, wherein the blank sole element (1') provided in step a) comprises a plurality of tubular channel structures (3, 4) forming a channel structure network, the channel structure network comprising at least two openings (31, 32, 41) providing fluid communication between the inside of the plurality of tubular channel structures (3, 4) and the environment outside the sole element (1).

9. 9. The method according to any one of claims 1 to 8, wherein the blank sole element (1') provided in step a) comprises a plurality of tubular channel structures (3, 4), said plurality of tubular channel structures (3, 4) comprising a plurality of main channel structures and one or more connecting channel structures, the one or more connecting channel structures fluidly connecting two or more main channel structures to each other.

10. 10. The method according to any one of claims 1 to 9, wherein in step b, the fibres and the resin are introduced simultaneously.

11. 11. The method according to any one of claims 1 to 10, wherein at least one of the one or more tubular channel structures (3, 4) comprises a branching portion (42), at which the at least one tubular channel structure (3, 4) branches into two or more sub-channel structures (43, 44).

12. 12. The method according to any one of claims 1 to 11, wherein the fiber composite (5) is injected such that the tubular channel structures (3, 4) are filled with more than 90%, in particular more than 95%, more particularly more than 98%, more particularly 100% of their channel volume.

13. A sole element (1), in particular a sole element (1) obtainable by the method according to any one of claims 1 to 12, said sole element (1) comprising one or more tubular channel structures (3, 4), and wherein a cured fiber composite (5) comprising fibers and a resin is introduced, preferably injected, into said one or more tubular channel structures (3, 4).

14. 14. The sole element (1) according to claim 13, further comprising a base body (2), wherein the one or more tubular channel structures (3, 4) extend along the base body (2).

15. 15. The sole element (1) according to claim 14, wherein the one or more tubular channel structures (3, 4) protrude from the base body (2).

16. 16. The sole element (1) according to claims 13 to 15, wherein the one or more tubular channel structures (3, 4) have channel walls with a wall thickness t, the channel walls defining channels with a maximum channel width w, preferably with a ratio of t to w between 1:150 and 1:3, in particular between 1:75 and 2:7, more particularly between 1:50 and 1:

4.

17. Sole element (1) according to any one of claims 13 to 16, wherein the resin of the cured fibre composite (5) is materially bonded directly to one or more tubular channel structures (3, 4).

18. The sole element (1) according to any one of claims 13 to 17, wherein the sole element (1) comprises a plurality of tubular channel structures (3, 4), the plurality of tubular channel structures (3, 4) comprising a main channel structure and one or more connecting channel structures, the one or more connecting channel structures connecting two or more main channel structures to each other.

19. 19. The sole element (1) according to any one of claims 13 to 18, wherein the sole element (1) comprises a plurality of tubular channel structures (3, 4) forming a channel structure network, at least some of the tubular channel structures (3, 4), in particular all of the tubular channel structures (3, 4) of the channel structure network being connected to one another.

20. The sole element (1) according to any one of claims 13 to 19, wherein the sole element (1) is a sole plate or a midsole.

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