EP3466291B1

EP3466291B1 - Sole for a shoe

Info

Publication number: EP3466291B1
Application number: EP18181579.6A
Authority: EP
Inventors: John Whiteman; Angus Wardlaw; Heiko Schlarb; James Michael Tarrier; Paul Leonard Michael Smith
Original assignee: Adidas AG
Current assignee: Adidas AG
Priority date: 2013-02-13
Filing date: 2014-01-28
Publication date: 2020-11-11
Anticipated expiration: 2034-01-28
Also published as: JP2017185287A; EP3804551A1; JP6491697B2; EP3466291A1; DE102013202353B4; DE102013202353A1; EP2845504A1; DE202014010460U1; JP2020146530A; JP6718533B2; EP2845504B1; JP2019081036A; JP6974540B2

Description

1. Technical field

The present invention relates to a sole for a shoe, in particular a sports shoe.

2. Prior art

By means of soles, shoes are provided with a plethora of properties which can be pronounced in various strengths, depending on the specific type of shoe. Primarily, shoe soles typically have a protective function. They protect the foot of the respective wearer, due to their increased stiffness compared to the shoe shaft, against injuries caused by, e.g., sharp objects on which the wearer may tread. Furthermore, the shoe sole, due to an increased abrasion resistance, usually protects the shoe against excessive wear. In addition, shoe soles can improve the grip of the shoe on the respective ground and thus enable faster movements. A further function of a shoe sole can consist in its providing certain stability. Furthermore, a shoe sole can have a cushioning effect, for example, by absorbing the forces occurring during contact of the shoe with the ground. Finally, a shoe sole can protect the foot from dirt and spray water or provide a plurality of other functionalities.
In order to satisfy this plethora of functionalities, different materials are known from the prior art from which shoe soles can be manufactured. Exemplarily, shoe soles made from ethylene-vinyl-acetate (EVA), thermoplastic polyurethane (TPU), rubber, polypropylene (PP) or polystyrene (PS) are mentioned here. Each of these various materials provides a special combination of different properties which are more or less well-suited for the specific requirements of the respective shoe type. TPU, for example, is very abrasion-resistant and tear-proof. Furthermore, EVA distinguishes itself by a high stability and a relatively good cushioning effect. In addition, the use of expanded materials, in particular of expanded thermoplastic urethane (eTPU), was taken into consideration for the manufacture of a shoe sole. Thus, for example, WO 2005/066250 A1 describes methods for the manufacture of shoes whose shoe shaft is adhesively connected to a sole on the basis of foamed thermoplastic urethane. Expanded thermoplastic urethane distinguishes itself by a low weight and particularly good elasticity and cushioning properties.
In addition to cushioning and absorbing the shock energy produced when the foot treads on the ground, i.e. a cushioning in vertical direction, it is further known form prior art that during running, also shear forces occur in horizontal direction, in particular on grounds where a shoe has a good grip and the shoe is hence stopped abruptly together with the foot when contacting the ground. In case these shear forces cannot be absorbed at least partially by the ground and/or the sole of the shoe, the shear forces are transmitted with undiminished effect to the movement apparatus, in particular the knee. This easily leads to an excessive burdening of the movement apparatus and promotes injuries. On the other hand, excessive shear capacity of the shoe sole would mean a loss of stability, in particular during faster running, which would lead to an increased risk of injuries. The increased shear capacity can also be undesired in specific regions of the sole, since these regions precisely serve to stabilize the foot. Furthermore, an increased shear capacity, e.g. in the area of the toes or of the midfoot, can give the wearer a sensation of slipping of the shoe during running, which can reduce the wear comfort.
In order to solve this problem, sole constructions are known from the prior art, e.g. from DE 102 44 433 B4 and DE 102 44 435 B4 , which can absorb in a way that does not strain the joints a part of the shear forces occurring during running. However, a disadvantage of these constructions consists in the fact that such soles are composed of several independent individual parts, have a fairly high weight and are expensive and complex in manufacture.
Moreover, US 2005/0150132 A1 discloses footwear (e.g., shoes, sandals, boots, etc.) that is constructed with small beads stuffed into the footbed, so that the beads can shift about due to pressure on the footbed by the user's foot during normal use. US 7,673,397 B2 discloses an article of footwear with support assembly having a plate and indentations formed therein. US 8,082,684 B2 discloses a sole unit for a shoe having at least one decoupling track between regions of sole unit allowing for the decoupling of the regions in response to forces from foot-ground contact. DE 10 2011108 744 A1 discloses a method for the manufacture of a sole or part of a sole for a shoe. WO 2007/082838 A1 discloses foams based on thermoplastic polyurethanes. US 2011/0047720 A1 discloses a method of manufacturing a sole assembly for an article of footwear. WO 2006/015440 A1 discloses a method of forming a composite material. US 2006/0010717 A1 discloses a therapeutic device which includes a supporting member that continuously and flexibly supports and bounds a plurality of small sized hard surfaced force members that support a user's foot during movement without clumping. US 2009/0013558 A1 relates to an article of footwear having an upper and a sole structure secured to the upper, wherein the sole structure has a plurality of support elements and wherein each of the support elements includes a shell and a core. EP 2 250 917 A1 discloses a midsole structure for shoes, including shoes with a vapor-permeable sole, designed for use in sports activities.
Starting from the prior art, it is therefore an objective of the present invention to provide better soles for shoes, in particular for sports shoes. A further objective is to provide improved possibilities by means of which the shear capacity of shoe soles can be selectively influenced in specific regions of the sole.

3. Summary of the invention

The claimed invention is defined by a sole according to independent claim 1 and a shoe according to independent claim 13. Further embodiments of the claimed invention are described in the dependent claims. Any "aspect", "embodiment", "example", etc. described in the following and not falling within the scope of the claimed invention thus defined is to be interpreted as background information provided to facilitate the understanding of the claimed invention.
According to a first aspect of the present disclosure, the above-mentioned problem is solved by a sole for a shoe, in particular a sports shoe, comprising a cushioning element which comprises randomly arranged particles of an expanded material. The sole further comprises a control element free from expanded material, wherein the control element reduces shearing motions in a first region of the cushioning element compared to shearing motions in a second region of the cushioning element.
The use of a cushioning element comprising expanded material is particularly advantageous for the construction of a shoe sole, since this material is very light, but is able, at the same time, to absorb the shock energy when the foot treads on the ground and to restore it to the runner. This increases the running efficiency and reduces the (vertical) impact burden upon the movement apparatus. A further advantage is provided by the use of randomly arranged particles of the expanded material. These considerably facilitate the manufacture of such a sole, since the particles a particularly easy to handle and, due to their random arrangement, no orientation is necessary during manufacture.
The use of a control element allowing for selectively controlling the shear capacity of the cushioning element furthermore allows for constructing soles that can also absorb and/or cushion horizontal shear forces which otherwise would have a direct impact on the movement apparatus, in particular the joints. This further increases the wear comfort of the shoe and the efficiency of the runner and prevents at the same time from injuries and wear of the joints. Since this control element is preferably free from expanded material, is has sufficient strength for complying with its control function.
In a preferred embodiment, the particles of expanded material comprise one or more of the following materials: expanded ethylene-vinyl-acetate (eEVA), expanded thermoplastic urethane (eTPU), expanded polypropylene (ePP), expanded polyamide (ePA), expanded polyether block amide (ePEBA), expanded polyoxymethylene (ePOM), expanded polystyrene (PS), expanded polyethylene (ePE), expanded polyoxyethylene (ePOE), expanded ethylene propylene diene monomer (eEPDM). According to the requirement profile of the sole, one or more of these materials can be advantageously used for the manufacture of the sole due to their substance-specific properties.
In a further preferred embodiment, the control element comprises one or more of the following materials: rubber, non-expanded thermoplastic urethane, textile materials, PEBA as well as foils and foil-like materials.
In a further preferred embodiment, the first region of the cushioning element comprises a higher intrinsic shear resistance than the second region of the cushioning element. The use of such a cushioning element with regions of different intrinsic shear resistance in combination with a control element, which locally influences the shear capacity of the cushioning element, offers great freedom and various adaption possibilities in the construction of a shoe sole.
In an embodiment, the control element has, in a first control region which influences the shearing motion of the cushioning element in the first region, a greater thickness and/or fewer holes than in a second control region which influences the shearing motion of the cushioning element in the second region. Based on the thickness and the number and size of the holes, etc., the bending and deformation resistance of the control element can be determined, for example. These properties of the control element can, for their part, influence the shear and the bending capacity of the different regions of the cushioning element.
In a preferred embodiment, the cushioning element is provided as a component of a midsole. In a further preferred embodiment, the control element is provided as a part of an outsole.
By means of the construction of the cushioning element as a part of a midsole and/or of the control element as a part of an outsole, the number of different functional components of the sole and the shoe can be minimized and, at the same time, the adaption and control possibilities of the sole properties can be increased. This simplifies, e.g., the construction of the shoe and can reduce its weight considerably. Furthermore, additional composite materials such as adhesives for bonding the different elements of the sole and the shoe are not required. Consequently, the manufacture of the shoe is eventually more cost-effective together with improved functionality and furthermore offers improved recycling possibilities, since materials of common material classes are preferably used.
In a further embodiment, the outsole comprises a decoupling region that is not directly attached to the second region of the cushioning element of the midsole. As explained in detail further below, this enables to further influence and/or increase the shear capacity of the sole. So, for example, a control element provided as a part of an outsole can be bonded by a gel or the like to a cushioning element provided as a part of a midsole. The gel allows a further shearing effect between the control element and the cushioning element and thus allows absorbing higher shear forces.
The control element and the cushioning element can be manufactured from materials of a common material class, in particular from thermoplastic urethane. This allows a simplified manufacture of the sole and the shoe. In particular, materials from a common material class can often be bonded with each other and processed together in a significantly easier way than materials from different classes.
The first region can be located in the medial region of the midfoot and the second region in the lateral region of the heel. The shear forces occurring during running are especially produced when the foot contacts the ground. This happens typically with the lateral region of the heel. For this reason, a good shear capacity of the sole for absorbing the shear forces is desirable there. In the medial region of the foot, however, a supporting effect and increased stability are often desired. This allows a better pushing the foot off the ground and can furthermore prevent a pronation of the foot which can lead to irritations and injuries.
The control element can further increase the bending resistance of the cushioning element in the first region compared to the second region. In particular, a control element designed as a part of an outsole can provide this functionality.
The sole can comprise a frame made from non-expanded material, in particular from ethylene-vinyl-acetate, which surrounds at least a part of the cushioning element. Such a frame enables, for example, a further control of the shear capacity and can also be used to increase the stability of the sole.
In a preferred embodiment, the cushioning element allows a shearing motion of a lower sole surface relative to an upper sole surface in longitudinal direction of more than 1 mm, preferably more than 1.5 mm and particularly preferably more than 2 mm. These values offer a good balance between a sufficient stability of the shoe sole and a high absorption capacity for horizontal shear forces.
Preferably, the control element is laser-cut from a blank. For example, the control element can be provided in form as an outsole, or part of an outsole, which is laser-cut from a blank.
In the simplest form, the blank may be provided as a material layer comprising, for example, one or more of the materials suitable for the manufacture of a control element/outsole mentioned above. It is also possible, for example, that the blanks are provided in different sizes, thickness, with predefined holes, bulges, etc. and they may also comprise the general outline of a foot or sole.
Laser-cutting the control element can provide for a large freedom in design for the control element. It can also provide for the opportunity of an individual customization of the control element, sole and shoe. It may, for example, allow for numerous fashion designs, an individualization of each sole or shoe. The customization may be sport specific or according to typical movements of a customer or otherwise customer related. Furthermore, the laser-cutting may automated to a large degree and maybe based on, e.g., online tools or other ordering methods.
The above mentioned customization features and online ordering may, however, also be used in connection with other embodiments of inventive soles and shoes described herein or otherwise conceivable, without the control element necessarily being laser-cut from a blank.
A further aspect of the claimed invention relates to a shoe, in particular a sports shoe, as defined by independent claim 13, comprising a sole according to one of the claimed embodiments. Here, individual aspects of the claimed embodiments of a sole can be advantageously combined with one another, depending on the requirement profile for the sole and the shoe. Furthermore, it is possible to leave single aspects aside, if these should be irrelevant for the respective purpose of the shoe.

4. Brief description of the figures

In the following detailed description, currently preferred examples of implementations and embodiments of the sole according to the invention are described with reference to the following figures:

Fig. 1: Embodiment of a shoe sole with a midsole and an outsole which selectively influences the shear capacity and the bending capacity of the midsole. The sole further comprises a reinforcing element which is partially embedded in the midsole, as well as a heel clip;
Fig. 2: Shoes with different soles which were used for the measurements of Figs. 3a - 9 ;
Figs. 3a-b: Comparison of the vertical compression of a midsole made from eTPU and a midsole made from EVA when the foot touches the ground;
Fig. 4: Measurements of the vertical compression of a midsole made from eTPU and a midsole made from EVA during an entire step cycle;
Figs. 5a-b: Comparison of local material stretch in the lateral side wall of a midsole made from eTPU and a sole made from EVA during a rolling motion of the foot from the heel region to the forefoot region during a step;
Figs. 6a-c: Measurements of the relative displacement of two measurement points at the opposite ends of the measurement sections represented in Figs. 7a -c during a complete step cycle for three different soles;
Figs. 7a-c: The measurement points used for the measurements in Figs. 6a -c are each located at the ends of the measurement sections delineated in Figs. 7a -c;
Figs. 8a-c: Comparison of the horizontal shear effect exerted on the sole material of three different midsoles when touching the ground with the lateral heel region;
Fig. 9: Measurements of the shear effects in the heel region of the sole material of different midsoles in longitudinal direction (AP direction) during an entire step cycle;
Figs. 10a-d: Further measurements of the shear effects in the heel region of the sole material of various midsoles in longitudinal direction (AP direction) and in medial direction (ML direction) during an entire step cycle;
Fig. 11: Average values of several measurements of the shear effects in the heel region of the sole material of respective different midsoles in longitudinal direction (AP direction) during an entire step cycle;
Fig. 12: Average values of several measurements of the shear effects in the heel region of the sole material of respective different midsoles in medial-lateral direction (ML direction) during an entire step cycle;
Figs. 13a-e: Representation of the plantar shearing effect on the sole material of different midsoles, at the end of a step, when the foot is pushed off the ground in the forefoot region (cf. Fig. 13e );
Figs. 14a-c: Preferred embodiment of a shoe with a sole according to an aspect of the present invention;
Figs. 15a-c: Further preferred embodiment of a shoe with a sole according to an aspect of the present invention;
Figs. i6a-b: Preferred embodiment of a shoe sole with a midsole and an outsole which selectively influences the shear capacity and the bending capacity of the midsole;
Fig. 17: Particularly preferred embodiments of a shoe sole with a midsole and an outsole which selectively influences the shear capacity and the bending capacity of the midsole;
Fig. 18: Schematic representation of possible embodiments for outsoles which selectively influence the shear and bending capacity of a midsole;
Figs. 19,20: Schematic cross-section in ML direction through two embodiments of a midsole which comprises a first and a second plate element which can perform a sliding movement relative to each other;
Figs. 21a-b: Embodiment of a shoe according to the invention with an embodiment of a sole according to the invention comprising a control element laser-cut from a blank; and
Figs. 22a-d: Further currently preferred embodiments of shoes according to the invention with embodiments of shoe soles according to the invention.

5. Detailed description of preferred embodiments

In the following detailed description, embodiments relating to sports shoes are described. It is, however, emphasized that the present disclosure is not limited to these embodiments, and it can, for example, also be applied to safety shoes, casual shoes, trekking shoes, golf shoes, winter shoes or other shoes as well as for protective clothing and paddings in sports apparel and sports equipment.
Fig. 1 shows a sole 100 according to an aspect of the present invention. The sole 100 comprises a cushioning element 110 which comprises randomly arranged particles of an expanded material, as well as a control element 130 which selectively influences the shear capacity of the cushioning element.
In a preferred embodiment, the cushioning element 110 is provided, as shown in Fig.1 , as a midsole or a part of the midsole, respectively. The cushioning element 110 comprises randomly arranged particles of an expanded material. In an embodiment, the whole cushioning element 110 consists of expanded material. Here, however, different expanded materials, or mixtures of several different expanded materials, can be used in various partial regions of the cushioning element 110. In a further embodiment, only one or more partial regions of the cushioning element 110 consist of expanded material, while the rest of the cushioning element 110 consists of non-expanded material. For example, a cushioning element 110 can comprise a central region of particles of one or more expanded materials, said central region being surrounded by a frame of non-expanded material in order to increase the form stability of the sole. By means of an appropriate combination of expanded and/or non-expanded materials, a cushioning element 110 with the desired cushioning and stability properties can be manufactured.
The particles of the expanded material can, in particular, comprise one or more of the following materials: expanded ethylene-vinyl-acetate (eEVA), expanded thermoplastic urethane (eTPU), expanded polypropylene (ePP), expanded polyamide (ePA), expanded polyether block amide (ePEBA), expanded polyoxymethylene (ePOM), expanded polystyrene (PS), expanded polyethylene (ePE), expanded polyoxyethylene (ePOE), expanded ethylene propylene diene monomer (eEPDM). Each of these materials has specific characteristic properties which, depending on the requirement profile for the sole, can be advantageously used for the manufacture of the shoe sole. In particular eTPU has excellent cushioning properties which remain unchanged also at lower or higher temperatures. Furthermore, eTPU is very elastic and restores the energy stored during compression, e.g. when treading on the ground, almost entirely to the foot during subsequent expansion. On the other hand, EVA, for example, distinguishes itself by great strength and is therefore suitable, e.g., for the construction of a frame which surrounds regions of expanded material or the whole cushioning element 110, so as to give the cushioning element 110 high form stability.
The use of various materials or mixtures of different materials for the manufacture of the cushioning element 110 further allows for providing cushioning elements 110 comprising regions with different intrinsic shear resistances. In connection with a control element 130, as described herein, this significantly increases the freedom of design in the construction of shoe soles 100 and thereby the possibilities of selectively influencing the shear behavior of the shoe sole 100.
In a preferred embodiment, the control element 130, as shown in Fig. 1 , is provided as an outsole or as a part of an outsole. The control element 130 here preferably comprises one or more of the following materials: rubber, non-expanded thermoplastic urethane, textile materials, PEBA as well as foils or foil-like materials. In a particularly advantageous embodiment, the cushioning element 110 and the control element 130 are manufactured from materials of a common material class, in particular expanded and/or non-expanded thermoplastic urethane. This significantly simplifies the manufacturing process, as, for example, the cushioning element 110 and the control element 130 can be provided as one integral piece in a single mold without additional use of adhesives.
In order to selectively influence the shear behavior of the cushioning element 110, the control element has a number of protrusions 132 which are different in size, hardness and expansion, elevations or bulges 135 of different lengths, thicknesses and structures, as well as openings and recesses 138 with different diameters. By varying these design possibilities, the influence exerted by the control element 130 on the shear behavior of the cushioning element 110 can be selectively controlled.
Figs. i6a-b, for example, show an embodiment 1600 of a sole 1610 according to the invention for a shoe which comprises a cushioning element 1630 provided as a midsole and which comprises randomly arranged particles 1635 of an expanded material. Fig. 16a shows the unloaded state and Fig. 16b shows the loaded state after touching 1650 the ground. The sole 1610 further comprises a control element 1620 provided as an outsole and which comprises a number of protrusions 1622 as well as a number of recesses/depressions 1628. Here, the material of the control element 1620 preferably has a higher strength/stiffness than the material of the midsole 1630. For example, the control element 1620 can be provided as a foil onto which the protrusions 1622 can be selectively applied. For example, the control element 1620 can be a foil from TPU onto which protrusions 1622 also made from TPU can be applied. Such a preferred embodiment has the advantage that the foil and the protrusions, for example, can enter into a chemical bond without using additional bonding agents and which is extremely stable and resistant. In other embodiments, the control element comprises other/additional materials.
As shown in Fig. 16b , after touching 1650 the ground, the protrusions 1622 press into the material of the midsole 1630, since the material of the control element 1620, as already mentioned, is preferably of a higher stiffness/strength than the material of the midsole 1630. Thereby, regions 1660 and 1670 are formed in which the material of the midsole 1630 is compressed to varying degrees.
In particular the material of the midsole in the regions 1670, in which the protrusions 1622 press under load into the midsole 1630, is compressed to a higher degree than in the regions 1660, in which the control element comprises recesses/depressions 1628. The different compressions of the midsole material caused thereby selectively influence the stretching and/or shear capacity of the midsole material in the corresponding regions 1660 and 1670. For example, the stretching capacity of the midsole material decreases in the further compressed regions 1670 compared to the less compressed regions 1660. Furthermore, this leads to an anchoring of the midsole 1630 at the outsole 1620 and hence to an increased ground grip.
Thus, the stretching and/or shear capacity of the midsole 1630 is selectively activated or suppressed in individual partial regions by means of different designs of the control element 1620 with varied protrusions 1622.
The protrusions 1622 can be of varied design. For example, the protrusions 1622 can be pointed, cone-shaped or pyramid-shaped, the protrusions 1622 can be cylindrical, they can be hemispherical, the control element 1620 can be wave-like and so forth. The protrusions 1622 here serve as a kind of anchor points which allow for a targeted local compression of the midsole material. Widely spaced protrusions 1622 here allow, for example, for greater stretching movements of the midsole materials than closer spaced protrusions 1622. The shear capacity of the midsole 1630 can also be selectively influenced thereby.
Fig. 17 shows a particularly preferred embodiment 1700 of a sole 1710 according to the invention that comprises a cushioning element 1730 provided as a midsole and which comprises randomly arranged particles 1735 of an expanded material, in unloaded state. The sole 1710 further comprises a control element 1720 provided as an outsole, said control element comprising a number of protrusions 1722 and a number of recesses/depressions 1728. The material of the control element 1720 here preferably has a higher strength/stiffness than the material of the midsole 1730. The symmetrical, wave-like design of the control element shown in Fig. 17 allows, on the one hand, a particularly good anchoring of the midsole 1730 to the outsole 1720 under load, as described above, and thus a particularly good ground grip. Furthermore, a control element 1720 designed in such a way can be introduced without any problem into a mold used for manufacture, during the manufacturing process.
Fig. 18 schematically shows further embodiments of control elements 1800a, 1800b, 1800c and 1800d according to the invention. The embodiments 1800a, 1800b, 1800c and 1800d, preferably provided as an outsole or parts thereof, comprise a number of protrusions 1810 as well as depressions and/or reinforcing elevations 1820 which can, for example, connect two protrusions to each other. Here, the protrusions 1810 can comprise a number of different shapes, sizes, heights, etc., as already discussed above. The same applies to the depressions and/or reinforcing elevations 1820. For example, their width/thickness and/or depth/height as well as their position and orientation on the control elements 1800a, 1800b, 1800c and 1800d can be adapted to the sole according to the respective requirements in order to selectively influence the properties of the sole. Here, too, it is explicitly emphasized that the depressions and/or reinforcing elevations 1820 need not perforce be arranged between two protrusions 1810, but serve as stand-alone possibilities to design control elements according to the invention. In particular, such a reinforcing elevation can be advantageously used in the medial midfoot region (cf. 1455) in order to increase the stability of the sole there and to reduce the shear and stretching capacity of the midsole material in this region.
Furthermore, a control element can, according to a further aspect of the invention, comprise additional functional elements, such as, e.g., a torsion- and/or reinforcing element and the like, as a component and be manufactured as one integral piece therewith.
In addition, a control element can be provided as a complete outsole. In a further embodiment, however, an outsole comprises a number of individual independent control elements which may also be connected to each other.
In a preferred embodiment, the first region, which has a reduced shear capacity as compared to the second region, is located in the medial region of the midfoot, while the second region is located in the lateral region of the heel. In a particularly preferred embodiment, the control element 130 comprises in particular a stabilizing bulge 135 at the medial edge of the midfoot region, as well as a number of openings with a diameter increasing towards the heel and the tip of the foot. The shear behavior of the cushioning element 110 adjusted in this way advantageously supports the natural physiological processes in the movement apparatus of a runner and increases the wear comfort and the efficiency of the runner, along with a minimization of the risk of injuries.
Besides influencing the shear behavior of the cushioning element 110, the control element can also influence the bending resistance of the cushioning element. For example, if the control element 130 is firmly attached to the cushioning element 130 in a region, the bending resistance of the control element 130 also influences the bending resistance of the cushioning element 110. The bending resistance of the control element 130, for its part, depends, for example, on the above-mentioned design options of the control element 130. So, in the preferred embodiment shown in Fig. 1 , the bending resistance in the heel and toe region is lower than in the midfoot region which is stabilized by means of the reinforcing bulge 135.
In a further preferred embodiment, the sole 100 further comprises a decoupling region 160. In this region, the cushioning element 110 and the control element 130 are not directly connected to each other. In one embodiment, there is no connection at all between the cushioning element 110 and the control element 130 in this region. In a preferred embodiment, the cushioning element 110 and the control element 130 are bonded in this region by means of a material which has a shear capacity. In a particularly preferred embodiment, this material with shear capacity comprises, for example, one or more of the following materials: eTPU, foamed material or a gel. This enables a further shearing motion of the cushioning element 110 with respect to the control element 130 and thus an additional possibility of influencing the shear behavior of the sole 100. Such a decoupling region 160 is preferably located in the lateral heel region, since here, as will be shown further below in greater detail, the strongest shear forces occur during running.
Fig. 19 shows a cross-section in medial-lateral direction through an embodiment of a midsole 1900 according to the present invention comprising randomly arranged particles 1910 of an expanded material and which can be advantageously combined with the other aspects of the present invention described herein. In the embodiment shown in Fig. 19 , the whole midsole 1900 consists of expanded material. It is, however, clear to the skilled person that this is merely a specific example of a midsole 1900 according to the invention, and that in other embodiments only one or more partial regions of the midsole 1900 can comprise particles 1910 of expanded material. The midsole further comprises a first plate element 1920 and a second plate element 1930 that can slide relative to each other. Particularly preferred is a design in which the plate elements 1920 and 1930 can perform a sliding movement in several directions. In a preferred embodiment, the two plate elements 1920 and 1930 are completely surrounded by the material of the midsole 1900, particularly preferred by the expanded material 1910 of the midsole 1900. In other embodiments, however, the plate elements 1920 and 1930 are only partially surrounded by the material of the midsole 1900.
Preferably, the two plate elements 1920 and 1930 are arranged, as shown in Fig. 19 , in the heel region of the midsole 1900 such that they are located directly opposite each other. In a further embodiment, there is a lubricant or a gel or the like between the two plate elements 1920 and 1930, which counteracts wear of the plate elements 1920, 1930 caused by the sliding movement and facilitates sliding.
By the sliding movement of the two plate elements 1920 and 1930, such an arrangement can, for example, absorb or reduce, respectively, the horizontal shear forces acting on the movement apparatus of the wearer when he treads on the ground. This prevents wear of the joints and injuries of the wearer, in particular when he/she is running/walking fast. In other embodiments, the arrangement shown can also be located in a different region of the midsole 1900, for example, in order to further support the rolling of the foot during a step.
In a further embodiment (not shown), the two plate elements 1920 and 1930 each comprise, in addition, a curved sliding surface. In a preferred embodiment, the curvature of the two sliding surfaces is chosen such that the two sliding surfaces match positively. By an appropriate selection of the degree and orientation of the curvature, it is possible to influence in which direction the sliding movement of the first plate element 1920 relative to the second plate element 1930 preferably takes place, for example, when treading on the ground. This, again, exerts an influence on the shear forces which are absorbed by the midsole or passed on to the wearer, respectively.
Further preferred embodiments of such plate elements which can slide relative to each other and which can be advantageously combined with one or more of the embodiments described herein that belong to the disclosure are to be found in DE 102 44 433 B4 and DE 102 44 435 B4 .
For the functionality described just now it is further advantageous if the material of the midsole 1900 counteracts the sliding movement of the two plate elements 1920 and 1930 by a restoring force. Preferably, this restoring force is due to the fact that the two plate elements 1920 and 1930 are surrounded by the material of the midsole 1900, in particular the expanded material 1910 of the midsole 1900, and that the material of the midsole 1900 is compressed by the movement of the first and the second plate element 1920 and 1930, respectively, in the regions which are adjacent to the two plate elements 1920 and 1930 in the direction of the sliding movement. Due to the elastic properties of the material, in particular of the expanded material 1910 of the midsole 1900, a restoring force is produced which counteracts the sliding movement of the first and the second plate element 1920, 1930, respectively, with no need for complicated mechanics to this effect.
Fig. 20 shows a cross-section in medial-lateral direction of a variation of the embodiment discussed just now with a midsole 2000, which comprises randomly arranged particles 2010 of expanded material. The midsole comprises a plate element 2020 and a second, sled-shaped element 2030. The two elements 2020, 2030 can perform a sliding movement relative to each other. Due to the sled-shaped design of the second element 2030, a preferred direction for such a sliding movement is predetermined. In a preferred embodiment, however, there are voids 2040 between the first element 2020 and the second, sled-shaped element 2030 which also allow for small sliding movements of the two elements 2030 and 2040 relative to each other and which do not lie in the preferred direction mentioned above. By adapting the size of the voids 2030, the extent of such sliding movements which do not lie in the preferred direction can be individually adapted to the needs and requirements of the sole. So, very small voids 2040 allow for sliding movements of the two elements 2020 and 2030 almost exclusively in the preferred direction, which can lead to an increased stability of the sole. Larger voids 2040, however, facilitate noticeable sliding movements also in a non-preferred direction. This enables, for example, a better absorption of the horizontal shear forces by the sole when contacting the ground.
In the preferred embodiment shown in Fig. 1 , the cushioning element 110 further surrounds an element 120 at least partially, for example, a torsion or reinforcing element. In a preferred embodiment, the element 120 has higher deformation stiffness than the expanded material of the cushioning element 110. The element 120 hence can serve to further influence the elasticity- and also shear properties of the sole 100. In a further embodiment, the element 120 can, for example, also be an element serving the optical design and/or an element for receiving an electronic component and/or an electronic component or any other functional element. In case the element 120 serves to receive a further element, such as, e.g., an electronic component, then it has preferably a hollow region which is accessible from the outside. In the embodiment shown in Fig. 1 , such a cavity could, e.g., be located in the region of the recess 140. I in a preferred embodiment, the element 120 is not bonded, for example by an adhesive bond, with the cushioning element 110. In particular, the element does not comprise, in a preferred embodiment, a bond with the expanded material of the cushioning material 110. Since the cushioning element 110 partially surrounds the element, such a bond for fixing the element 120 is not required. Therefore, also non-glueable materials can be used for manufacturing the shoe. In a further embodiment, the element 120 can also be connected/bonded with the control element 130 in individual regions, for example by means of a bond such as, e.g., an adhesive bond, or be provided as one integral piece.
In the embodiment shown in Fig. 1 , the sole 100 further comprises a heel clip 150. Preferably, the heel clip 150 comprises a lateral finger and a medial finger which independent from each other encompass the lateral and the medial side of the heel. This allows a good fixation of the foot on the sole 100 without at the same time excessively restraining the room to move of the foot. In a further preferred embodiment, the heel clip 150 further comprises a recess in the region of the Achilles' tendon. This prevents a chafing or rubbing in particular of the upper edge of the heel clip 150 on the Achilles' tendon in the region above the heel. In a preferred embodiment, the heel clip 150 can further, be bonded, e.g. by a bond, to the control element 130 and/or the element 120 or be provided together with this as one integral piece.
Fig. 2 shows four different shoes 200, 220, 240 and 260 which were used for taking measurements of elasticity and shear properties of soles from various materials. The most important results of these measurements are summarized in the following Figs. 3a - 9 .
The shoe 200 is a shoe with an upper 205 as well as a shoe sole 210 and a sliding element 212, such as described, for example, in DE 102 44 433 B4 and DE 102 44 435 B4 .
The shoe 220 comprises an upper 225 as well as a midsole 230 from eTPU which is surrounded by a frame from EVA. The EVA can, for example, be a compression molded 020 55C CMEVA which has a density of 0.2 g/cm^3 and a hardness of 55asker C.
The shoe 240 comprises an upper 245 as well as a midsole 250 of EVA.
Furthermore, the shoe 260 comprises an upper 265 as well as a midsole 270 of eTPU.
Figs. 3a, 3b and 4 show the vertical (i.e. the direction from foot to ground) compression of the soles of eTPU (shoe 260) and EVA (shoe 240).
For measuring these and further discussed properties of the various materials and sole designs, for each measurement a large number (>100) of pictures, referred to as "stages", were taken in the course of a step cycle. These are continuously numbered starting from 1. For each measurement there is hence a one-to-one correspondence between the number or "stage" of a take and the point in time of this take within the respective step. However, it has to be noted that between different measurements there may be a certain time offset for the individual stages, i.e. the stages with an identical number from various measurements do not perforce correspond to the same point in time during the step measured in the respective measurement.
Pictures 300a and 300b of Figs. 3a and 3b were taken during the heel touching the ground. Figs. 3a and 3b show the compression in percent of the respective midsole regions compared to the unloaded state of the sole. As expected, no compression occurs in the forefoot region (cf. 320a, 320b) while the ground is touched by the heel. In the heel region, however, noticeable compressions are visible on the sole of eTPU (cf. 310a). The measurements therefore show that eTPU yields significantly more strongly under vertical load than EVA. Furthermore, the energy stored during compression of the eTPU sole is essentially restored to the runner in the course of the step. This increases the running efficiency significantly.
This is also confirmed by Fig. 4 . On the horizontal axis, the number of the respective stage, i.e. the time, is shown, and on the vertical axis, the vertical compression of the midsole is shown. The measured values 410 for a sole 270 from eTPU are shown as well as the measured values 420 for a sole 250 from EVA. At the time of the maximum vertical load, the EVA midsole 250 can be depressed only by about 1.3 mm, while the eTPU midsole 270 can be depressed by about 4.3 mm. Generally, the values of the vertical compression for eTPU compared to those of EVA range from 2:1 to 3:1, in some embodiments even above this.
Figs. 5a and 5b show the local material stretch of the midsole material compared to the unloaded state of the sole within the lateral side wall of the eTPU midsole 270 (measurement 500a) and the EVA midsole 250 (measurement 500b), also at a moment when the heel touches the ground. In addition to a percent indication of the material stretch compared to the unloaded state of the sole, the pictures of Figs. 5a and 5b indicate, however, also the direction of the material stretch in the form of stretch vectors. From the pictures, it can be seen that in the eTPU midsole 270, significantly greater material stretches occur than in the EVA midsole 250. This is due to the better shear capacity of eTPU compared to EVA. Therefore, eTPU is particularly appropriate for manufacturing a cushioning element for absorbing shear forces during running. In the example discussed here, the material stretch with eTPU is 2 - 3 times higher than with EVA. More precisely, the material stretch of eTPU is on average a stretch of 6-7%; the maximum stretch is 8-9%; the material stretch for EVA is on average a stretch of 2%; the maximum stretch is 3-4%.
Furthermore, the measurements reveal that the material stretch in the lateral side wall of the eTPU midsole 270 and of the EVA midsole 250 follow the natural shape of the metatarsal arch during running, i.e. the shoe follows the rolling movement of the foot. This is advantageous for the wear comfort and fit of the foot.
Figs. 6a-6c show the measurements 610a, 610b and 610c of the relative offset of two measurement points in millimeters, which are each located at the opposite ends of the measurement sections 710a, 710b and 710c shown in Figs. 7a - 7c . The measurements 610a 610b and 610c each comprise a complete step cycle. In Figs. 7a -c, the shoes used for the respective measurements are shown in a starting position.
Figs. 6a, 7a show the measurement results and the measurement points for a shoe 200 with a shoe sole 210 and a sliding element 212, as described in DE 102 44 433 B4 and DE 102 44 435 B4 .
Figs. 6b, 7b show the measurement results and the measurement points for a shoe 220 with a midsole 230 of eTPU and an EVA rim.
Figs. 6c, 7c show the measurement results and the measurement points for a shoe with an EVA sole 250.
It is clearly visible that the sliding element 212 of the shoe 200 and the eTPU sole with EVA rim 230 allow significantly greater offsets between the two measurement points than the EVA midsole 250. This means a better shear capacity of the lower midsole surface relative to the upper midsole surface and thus a better absorption capacity of the shear forces occurring during running. It is to be noticed that the shoe 220 which is simpler in construction allows offset values of up to 2.5 mm (cf. Fig. 6b ), while the shoe 200 with the sliding element 212 allows only offset values of up to about 2 mm (cf. Fig. 6a ). The shoe 240 with EVA midsole 250, in contrast, allows only offset values of up to about 0.5 mm (cf. Fig. 6c ).
The Figs. 8a - 8c show further measurements of the shear behavior of the shoe 200 with the sliding element 212 (measurement 800a), of the shoe 220 with eTPU midsole with EVA rim 230 (measurement 800b), and of the shoe 240 with EVA midsole 250 (measurement 800c). What is shown is the local offset of the sole material compared to the unloaded state at a moment when the heel touches the ground.
It is clearly visible that the shoe 200 with the sliding element 212 and the shoe 220 with eTPU midsole with EVA rim 230 have a substantially higher shear capacity in the region of the heel than the shoe 240 with EVA midsole 250.
Fig. 9 again shows measurement results of measurements of the shearing in the midsole material in longitudinal direction (AP direction) during a complete step cycle for four different shoes.
The curve 910 shows again the measurement results of Fig. 6a for the shoe 200 with the sliding element 212, with a maximum shearing of about 2 mm when the heel touches the ground. The curve 930 again shows the measurement results of Fig. 6b for the shoe 220 with eTPU midsole with EVA rim 230 with a maximum shearing of about 2.5 mm during the touching of the ground by the heel. The curve 940 again shows the measurement results of Fig. 6c for the shoe 240 with EVA midsole 250 with a maximum shearing of about 0.5 mm during the impacting on the ground with the heel. The curve 920, finally, shows the measurement results of a measurement carried out in the same way for the shoe 260 with eTPU midsole 270 with a maximum shearing of about 1.8 mm during the touching of the ground by the heel.
One can thus recognize that the shoe 260 with the eTPU midsole 270 and in particular the shoe 220 with eTPU midsole with the EVA rim 230 have a very good shear capacity and thus are principally well-suited for the construction of midsoles.
Figs. 10a - 13d show further measurements of the shear capacity of differently designed soles.
Figs. 10a - 10d show measurements of the changes in length of measurement sections of which one is arranged in longitudinal direction (AP direction) and one in medial-lateral direction (ML direction) in the heel region of the sole during a step cycle. These changes in length provide information on the plantar shear capacity of the respective sole.
Fig. 10a shows the change in length 1010a of the measurement section 1015a extending in AP direction, and the change in length 1020a of the measurement section 1025a, which extends in ML direction, for a shoe with an EVA midsole without outsole, as, e.g., the shoe 240. The measurements indicate a maximum change in length of about 1.2 mm in AP direction and of about 0.3 mm in ML direction.
Fig. 10b shows the change in length 1010b of the measurement section 1015b extending in AP direction and the change in length 1020b of the measurement section 1025b extending in ML direction for a shoe with an eTPU midsole without outsole, as, e.g., the shoe 260. The measurements show a maximum change in length of about 3.5 mm in AP direction and of about 1.5 mm in ML direction.
Fig. 10c shows the change in length 1010c of the measurement section 1015c extending in AP direction and the change in length 1020c of the measurement section 1025c extending in ML direction for a shoe with a sliding element, as for instance the shoe 200. The measurements show a maximum change in length of about 3.2 mm in AP direction and of about 0.7 mm in ML direction.
Fig. 10d shows the change in length 1010d of the measurement section 1015d extending in AP direction and the change in length 1020d of the measurement section 1025d extending in ML direction for the preferred embodiment of a shoe 1400 according to Figs. 1 and 14a - 14c comprising a midsole, which comprises eTPU, as well as a control element 1450 (cf. below) provided as an outsole. The measurement show a maximum change in length of about 3.4 mm in AP direction and a negative change in length of about 0.5 mm in ML direction. In particular the negative change in length in ML direction means a very good stability of the shoe in the midfoot region which reflects the influence of the medial reinforcement 1455 of the control element 1450.
Figs. 11 and 12 show the average values of a series of measurements conducted analogously to the measurements shown in Figs. 10a - 10d .
Fig. 11 shows the average change in length of the measurement section extending in AP direction during a complete step cycle for a shoe with a sliding element, as, for example, the shoe 200 (cf. curve 1110), for a shoe with an eTPU midsole, as, for example, the shoe 260 (cf. curve 1120), for a shoe with an EVA midsole, as, for example, the shoe 240 (cf. curve 1130) and for the shoe 1400 according to Figs. 14a - 14c (cf. curve 1140).
Fig. 12 shows the average change in length of the measurement section extending in ML direction during a complete step cycle for a shoe with a sliding element, as, for example, the shoe 200 (cf. curve 1210), for a shoe with an eTPU midsole, as, for example, the shoe 260 (cf. curve 1120), for a shoe with an EVA midsole, as, for example, the shoe 240 (cf. curve 1230), and for the shoe 1400 according to Figs. 14a - 14c (cf. curve 1240).
As can be inferred from Figs. 11 and 12 , the shoe 1400 according to a particularly preferred embodiment has, with a maximum change in length in AP direction of more than 3 mm, the best shear capacity of all four tested shoe types. At the same time, the shoe 1400 shows a sufficient stability in ML direction, as can be seen from Fig. 12 . As shear forces occur during running mainly in AP direction, and since a bending/slipping of the foot in ML direction is to be avoided as far as possible, this combination of properties of the shoe is particularly advantageous.
In further preferred embodiments, the cushioning element enables a shearing motion in AP direction of a lower sole surface relative to an upper sole surface of more than 1 mm, preferably more than 1.5 mm and particularly preferably more than 2 mm. A selection between different values of the shear capacity of the cushioning element enables to adapt the shoe sole individually to the needs and physiological conditions of a runner. The values discussed here serve the skilled person only as a guideline in order to obtain an impression of typical preferred values of the shear capacity of a cushioning element. In individual cases, these values ideally have to be specifically adapted to the wishes and needs of the wearer.
Figs. 13a - 13d show the plantar material stretch in the sole of various shoes in percentages, compared to the unloaded state of the shoe, at the moment when the foot is pushed off the ground via the forefoot, as schematically shown in Fig. 13e . Figs. 13a - 13d furthermore show the stretch vectors which locally indicate the direction of the material stretch. Fig. 13a shows a measurement 1300a for a shoe 240 with an EVA midsole, Fig. 13b shows a measurement 1300b for a shoe 260 with an eTPU midsole. Fig. 13c shows a measurement 1300c for a shoe with a sliding element, as, for example, the shoe 200, and Fig. 13d shows a measurement 1300d for the preferred embodiment of a shoe 1400 according to Figs. 1 and 14a - 14c, which comprises a midsole comprising eTPU, as well as a control element 1450 provided as an outsole (cf. below).
As can clearly be seen from the figures, in this position of the foot/shoe (i.e. when pushing the foot off the ground over the forefoot region, cf. Fig. 13e ) the main load and deformation of the material of the shoes 240 and 260 occurs locally in the middle of the forefoot region (cf. Fig. 13a and Fig. 13b ) (in other positions of the foot, the main load and deformation can also be observed in the heel region). In the case of the shoe with the sliding element and the shoe 1400, however, the material stretches follow the shape of the outsole. In Fig. 13d , in particular, the structure of the outsole 1450 with its openings 1452, elevations 1458 and protrusions 1459 can be seen. Furthermore, Fig. 13d shows that almost all of the stretch vectors in the forefoot region extend parallel in AP direction, i.e. the material stretches almost exclusively in AP direction, while it shows a good stability in ML direction. This is desirable for a dynamic push-off of the foot without losing stability. In case of insufficient stability of the sole in ML direction, the foot would otherwise be in danger of slipping sideways or bending, in particular at a higher running speed and, for instance, in a curve or on uneven terrain.
The control element 1450, e.g. in the form of an outsole, contributes to forming predefined zones where a specific shearing- and/or stretching behavior or a specific stability is required. The design of the control element 1450 can be adapted to the requirements of each sport. Linear sports have different requirements concerning the shearing behavior and stability of the sole than, for example, lateral sports. Therefore, the control elements 1450 and sole concepts can be individually designed for specific sports. For example, for sports like (indoor) football, basketball, or running sports, the best/most important shearing and stability zones can be determined and individually adapted. For example, in many fields of application, such preferred shearing and/or stretching zones are located beneath the big toe and in the heel region. Furthermore, by means of the aspects described herein, soles can be manufactured which can ideally imitate the rolling of the foot like when walking barefoot.
Figs. 14a - 14c show a preferred embodiment of a shoe 1400 with a cushioning element 1410 provided partially as a part of a midsole or as a midsole, said cushioning element comprising randomly arranged particles of expanded material, in particular particles of eTPU, and a control element 1450 provided as part of an outsole or as an outsole, which reduces the shear capacity of the midsole 1410 in the medial region of the midfoot compared to the lateral region of the heel. In addition, the shoe shown in Figs. 14a - 14 comprises an upper 1420. In a preferred embodiment, the shoe 1400 further comprises a heel clip 1430 as well as an additional torsion or stiffening element 1440, as already discussed above in connection with Fig. 1 and the corresponding embodiments.
In one preferred embodiment, the control element 1450 which is provided as an outsole does not comprise expanded material. Particularly preferred is the control element made from rubber, thermoplastic urethane, textile materials, PEBA or foils and foil-like materials or a combination of such materials, respectively. It is furthermore advantageous if the control element 1450 and the cushioning element 1410 are manufactured from materials from a common class of materials, as already mentioned above. Furthermore, the control element 1450 preferably comprises a number of openings 1452 of different sizes, a bulge 1455 in the medial region of the midfoot as well as a number of elevations 1458 and protrusions 1459. These elements serve, as already discussed, to influence the flexibility and stiffness properties of the control element 1450, which, for their part, influence the shear capacity and the bending stiffness of the sole and particularly the midsole 1410. The protrusions 1459 and the elevations 1458 can, furthermore, increase the ground grip, in particular, since the control element 1450 in the present preferred embodiment is provided as a part of an outsole.
The preferred embodiment shown in Figs. 14a - 14c , with a bulge 1455 in the medial region of the midfoot as well as a number of openings 1452 of varying diameter, enables a particularly good shear capacity in the heel region, especially in the lateral heel region, as well as a good stability in the medial midfoot region. As already mentioned several times, this combination of properties is particularly advantageous for use in case of running shoes. Other combinations of properties are, however, also possible, and the design options and embodiments presented herein enable the skilled person to manufacture a shoe having the desired properties.
Figs. 15a - 15c show a further preferred embodiment of a shoe 1500 according to an aspect of the present invention. The shoe 1500 comprises a cushioning element 1510 provided as a part of a midsole or as a midsole which comprises randomly arranged particles of expanded material, for example eTPU. Furthermore, the shoe 1500 comprises a control element 1540 provided as a part of an outsole or as an outsole which can selectively influence the shear capacity and the bending stiffness of the cushioning element 1510 in the way which was already repeatedly discussed. The shoe further comprises an upper 1520 as well as a heel clip 1530.
Figs. 21a -b show another preferred embodiment of a shoe 2100 according to the invention. The shoe 2100 comprises a sole comprising a cushioning element 2110 with randomly arranged particles of an expanded material. In the exemplary embodiment shown here, the cushioning element 2110 is provided as a midsole 2110. It may, however, also be merely a part thereof, for example.
The shoe 2100 furthermore comprises an upper 2120. The upper 2120 may be made from a large variety of materials and by a large variety of manufacturing methods. The upper 2120 can, in particular, be warp-knitted, weft-knitted, woven or braided, and it can comprise natural or synthetic materials, it may comprise fibers or yarns, multilaminate materials, compound materials and so on.
The sole of the shoe 2100 furthermore comprises a control element 2150, provided in the case at hand as an outsole 2150. In other cases it may only be part of an outsole or it may be part of the midsole. The control element 2150 is free from expanded material. Suitable materials for the control element/outsole 2150 may include rubber, non-expanded thermoplastic urethane, textile materials, PEBA as well as foils and foil-like materials.
The control element 2150 reduces shearing motions within a first region of the cushioning element 2110 compared to shearing motions within a second region of the cushioning element 2110. Reduced shearing may, for example, occur in regions 2160, 2165 where the control element 2150 comprises continuous regions of material. It may also occur in the regions of the "material webs" 2170, 2175, which are interspersed by holes 2152, 2155, 2158 in the control element 2150. In the regions of these holes 2152, 2155, 2158, for example, the shearing motion may be increased in comparison.
Taking account of the explanations regarding the inventive concept of controlling the shearing motion of a cushioning element as described in this document, it is clear to a skilled person that by choosing different designs and arrangements of the continuous material regions (like regions 2160, 2165), the "material webs" (like web 2170) and the holes (like holes 2152, 2155, 2158), the shearing and other properties, like e.g. the bending stiffness, torsional stiffness or the general roll-off behavior, of the midsole 2110 of the shoe 2100 can be influenced as desired in a large number of ways. The influence can be fine-tuned even further with the potential inclusion of bulges, elevations, protrusions in the control element 2150, as already described before.
In the present case, the control element 2150 is laser-cut from a blank (not shown). This may be done before the control element 2150 is affixed to the remaining parts of the sole of the shoe 2100, in particular the midsole 2110, and is preferably done in an automated manner, at least to a large degree. In principle, however, the blank may also be arranged at, e.g., the midsole 2110 first, then the blank is cut and finally the cut-out sections of the blank are removed. To this end, a bonding agent may be applied between the midsole 2110 and the blank, which does not immediately harden completely but still provides enough adhesion that the blank is secured on the midsole 2110 (or other parts of the shoe 2100) for it to be cut. For cutting, the shoe 2100 including the blank may e.g. be arranged on a last to allow three-dimensional positioning within a cutting device. After removal of the cut-out pieces of the blank, which is still possible since the agent has not completely hardened, the bonding agent may then be left to harden completely or this may be facilitated by heating, cooling, energizing or other means.
In the simplest form, the blank may be provided as a material layer comprising, for example, one or more of the materials suitable for the manufacture of a control element/outsole mentioned above. It is also possible, for example, that the blanks are provided in different sizes, thickness, with predefined holes, bulges, elevations, protrusions and so forth, which may already provide a basic pattern that may then be fine-tuned by the laser-cutting process. Such a basic pattern may, e.g., be adapted to specific movement patterns occurring during, say, a specific sporting activity and different blanks may be used for the manufacture of shoes 2100 for the different sporting activities. Examples may include blanks for running shoes, tennis shoes, basketball shoes, football shoes, etc. This approach can have the advantage that the blanks can be produced quickly and in a large number beforehand and the individual customization can then be carried out more efficiently and more quickly. To this end, the blanks may also already comprise the general outline of a foot or sole.
This can, in particular, become important, if the customization, particularly by laser-cutting, is done on the spot, for example in a sales room, a sales stand at a sporting event or he like, where the is only limited room for a cutting device and manufacturing apparatus.
Laser-cutting the control element 2150 can provide for a large freedom in design for the control element 2150. It can also provide for the opportunity of an individual customization of the control element 2150, sole and shoe 2100, as already mentioned. It may, for example, allow for numerous fashion designs and a corresponding individualization of each sole or shoe 2100. The customization may be sport specific or according to typical movements of a customer or otherwise customer related. Furthermore, the laser-cutting may be automated to a large degree and may be based on, e.g., online tools or other ordering methods.
While reference has been made to laser cutting throughout the description of Figs. 21a -b, other techniques are in principle also possible. Examples are CNC cutting, die cutting, water jet cutting.
Finally, Figs. 22a -d show further currently preferred embodiments of shoes 2200a, 2200b, 2200c, and 2200d according to the invention.
The main purpose of Figs. 22a -d is to give the skilled person a better understanding of the scope and further possible embodiments of the present invention. Therefore, the embodiments 2200a, 2200b, 2200C, and 2200d will only be discussed briefly. For a more detailed discussion of individual aspects, reference is made to the discussion of the embodiments of shoes, soles, midsoles, cushioning elements and control elements according to the invention already put forth herein, in particular the discussion of the embodiments 100, 1400, 1500, 1600, 1700, 1800a-d, 1900, 2000 and 2100. The features, options and functionality discussed in relation to these embodiments also apply to the embodiments 2200a, 2200b, 2200c, and 2200d, as far as applicable.
The shoes 2200a, 2200b, 2200C, 2200d each have a sole comprising a respective cushioning element 2210a, 2210b, 2210c and 2210d comprising randomly arranged particles of an expanded material. Whereas the cushioning elements 2210a and 2210b of the shoes 2200a and 2200b only extend throughout the forefoot regions, the cushioning elements 2210c and 2210d of the shoes 2200c and 2200d extend throughout the entire soles of the shoes 2200C, 2200d. The cushioning elements 2210a, 2210b, 2210c and 2210d shown here are provided as part of a respective midsole. Other arrangements of the cushioning elements are, however, also conceivable.
The soles of the shoes 2200a, 2200b, 2200c and 2200d furthermore each comprise a control element 2250a, 2250b, 2250c and 2250d free from expanded material. The control elements 2250a, 2250b, 2250c and 2250d each reduce shearing motions within a first region of the respective cushioning element 2210a, 2210b, 2210c and 2210d compared to shearing motions within a second region of the respective cushioning element 2210a, 2210b, 2210c and 2210d. In the embodiments 2200a, 2200b, 2200c and 2200d shown here, the control elements 2250a, 2250b, 2250c and 2250d are provided as part of a respective outsole.
The control elements 2250a, 2250b, 2250c and 2250d may further serve the purpose to selectively increase the bending resistance of the respective cushioning element 2210a, 2210b, 2210c and 2210d.
To influence the shearing motions and bending stiffness of the respective cushioning elements 2210a, 2210b, 2210c, 2210d or soles, the control elements 2250a, 2250b, 2250c and 2250d comprise a number of holes or openings 2252a, 2252b, 2252c, 2252d in different arrangements, shapes, sizes, sole regions, etc.. The control elements 2250a, 2250b, 2250c and 2250d further comprise a "web" or material mesh 2258a, 2258b, 2258c, 2258d between the individual openings 2252a, 2252b, 2252c, 2252d.
Whereas the openings 2252a, 2252b, 2252c and material meshes 2258a, 2258b, 2258c are configured in a diamond shape in the embodiments 2200a, 2200b and 2200C, the openings 2252d and material mesh 2258d roughly form parallelograms. Other configurations are, however, also possible, as already discussed at various times throughout this document and as shown, e.g., in the heel region of the shoe 2200d. Moreover, the control elements 2250a, 2250b, 2250c and 2250d may also comprise further protrusions, elevations, etc.. For example, as shown in Fig. 22a , the control element 2250a comprises a number of protrusions 2259a.
The recurring arrangement of the openings 2252a, 2252b, 2252c, 2252d and material meshes 2258a, 2258b, 2258c, 2258d in diamond or parallelogram shape may in particular result in one or more preferred directions along which the soles may predominantly shear or bend. By the exact patterns and arrangement of the holes and material regions, these preferred directions can be adjusted to a given requirement profile for a particular sole or shoe.

Claims

Sole for a shoe, in particular a sports shoe, comprising:
a. a midsole (1630; 1730) comprising randomly arranged particles (1635; 1735) of an expanded material; and

b. an outsole (1620; 1720) comprising a number of protrusions (1622; 1722) as well as a number of recesses and/or depressions (1628; 1728),

c. wherein the stretching capacity of the midsole is selectively activated or suppressed in individual regions of the midsole by the shape and position of the protrusions and recesses/depressions.
Sole according to claim 1, wherein the material of the outsole has a higher stiffness than the material of the midsole.
Sole according to one of claims 1 - 2, wherein the material of the midsole is compressed to a higher degree in regions (1670) of the midsole in which protrusions press into the midsole under a load on the sole, compared to the regions (1660) of the midsole where the outsole comprises recesses and/or depressions.
Sole according to claim 3, wherein the different compression of the midsole material in different midsole regions influences the stretching capacity of the midsole material in the corresponding regions.
Sole according to claim 4, wherein the stretching capacity decreases in the regions where the midsole material is more strongly compressed.
Sole according to one of claims 1 - 5, wherein widely spaced protrusions allow for greater stretching movements of the midsole material than more closely spaced protrusions.
Sole according to one of claims 1 - 6, wherein the outsole has a symmetrical, wave-like shape.
Sole according to one of claims 1 - 7, wherein the protrusions being pressed into the midsole material under a load on the sole provides for an anchoring of the midsole at the outsole to increase the grip of the sole on the ground.
Sole according to one of claims 1 - 8, further comprising a frame element made of or comprising ethylene vinyl acetate, preferably wherein the frame element surrounds the midsole region with the expanded material to increase the stability of the midsole region with the expanded material.
Sole according to one of claims 1 - 9, wherein the particles of the expanded material are randomly arranged.
Sole according to one of claims 1 - 10, wherein the expanded material comprises one or more of the following materials: expanded ethylene-vinyl-acetate, expanded thermoplastic urethane, expanded polypropylene, expanded polyamide, expanded polyether block amide, expanded polyoxymethylene, expanded polystyrene, expanded polyethylene, expanded polyoxyethylene, expanded ethylene propylene diene monomer.
Sole according to one of claims 1 - 11, wherein the outsole comprises one or more of the following materials: rubber, non-expanded thermoplastic urethane, textile materials, PEBA, a foil, a foil-like material.
Shoe (2100; 2200a-d), in particular sports shoe, comprising a sole according to one of claims 1 - 12.