Field of disclosure

The present invention lies in the field of sport shoe technology and relates in particular to a sole plate unit for a running shoe, as well as a shoe sole comprising such a sole plate unit.

Background, prior art

Midsoles with elastic plates for reducing the energy required by the runner during running, or for delaying runner fatigue are known in the prior art. These plates are typically stiffer than the rest of the midsole, which is typically formed from a foamed polymer material, while the plates may comprise carbon fibers. Such plates are mostly arranged in the forefoot area and optionally in the midfoot area of the midsole. If the runner shifts his weight in the running direction, i.e. towards the tip of the sole, the plate causes a forward propulsion effect. Such elastic plates are bent in the direction of the ground during the foot strike, i.e. tread, and the roll-off process and are thus biased, respectively tensioned. Due to the elastic properties of the plate, it returns to its original, typically flat, configuration when the foot is pushed off the ground, thereby supporting the push-off movement and saving force.

Summary of disclosure

Soles with such plates known in the prior art can however only exploit a relatively small amount of the forces acting on the sole for the push-off movement.

It is therefore a general object of the present invention to advance the state of the art regarding sole plates and advantageously overcome the disadvantages of the prior art fully or partly. In advantageous embodiments, a sole plate unit and a shoe sole with such a sole plate unit is provided which allows to use a larger portion of the forces acting on the sole plate unit during running as compared to the prior art. In further advantageous embodiments, an improved forward propulsion is achieved and/or runner's fatigue is delayed.

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

A first aspect of the invention relates to a sole plate unit for a running shoe. Such a sole plate unit is preferably configured for storing and releasing energy during running. The sole plate unit according to the invention comprises a sole plate and a polymer foam element. The sole plate comprises, or consists of, a base layer and a top layer. The base layer and the top layer are configured such that they define a compartment with a compartment volume. In particular, the compartment may be defined between the base layer and the top layer. The polymer foam element is arranged within the compartment defined by the base layer and the top layer and thus fills at least a portion of the compartment volume. The sole plate unit according to the invention provides for a propulsion with a larger horizontal vector as compared to prior art products. Thus, the runner is propelled more in the forward direction and less in the vertical direction, which provides additional support for the runner. It is understood that along a vertical direction of the sole plate unit, the polymer foam element is typically sandwiched between the base layer and the top layer.

In some embodiments, the sole plate is an integrally formed sole plate, i.e. it is a single piece.

In some embodiments, the base layer and the top layer are separate elements, i.e. they are not integrally formed. The base layer and the top layer are in such embodiments form locked and/or force locked to each other at a sole plate unit tip. For example, the sole plate unit may comprise a fastening structure at the sole plate unit tip which is configured to provide a form locking and/or force locking connection of the top layer and the base layer. In particular, the fastening structure may be configured to provide a compression force in the vertical direction on the base layer and the top layer, thereby pressing the top layer and the base layer onto each other. It is understood that this compression force acts along and against the vertical direction. In certain embodiments, the fastening structure may comprise two longitudinally extending bars defining a recess between them, wherein the top layer and the base layer are arranged within the recess. In some embodiments, the bars extend only along 2% to 30% of the length, i.e. the extension in the longitudinal direction, of the sole plate unit, in particular along 2% to 20%, more particular along 2% to 10% along the length of the sole plate unit. In certain embodiments, the fastening structure and in particular the longitudinally extending bars are made from an elastic material. In certain embodiments, the recess defined by the two bars has a thickness, i.e. extension in the vertical direction, which is smaller than the sum of the thickness of the top layer and the base layer. Due to the elastic material, the top layer and the base layer can be forced into the recess despite having a larger thickness, thereby deforming the fastening structure, respectively the bars, which provides for a force locking connection of the top layer and the base layer. The bars may have any suitable cross sectional shape, such as the shape of a circular segment, e.g. a half circle, or they may have a rectangular cross-sectional shape. The cross-sectional shape is the shape of the cross-section along a horizontal plane, i.e. a plane defined by the transverse and longitudinal direction of the sole plate unit. The fastening unit described in the embodiments above may be part of the sole plate unit as such, or it may also be part of a shoe sole as described herein below, in particular with respect to the second aspect of the invention.

Typical materials forthe polymer foam element may be polyurethanes, in particular expanded polyurethane, polyamide, polyether block amides, polyethylene vinyl acetate (EVA), polyolefins, polyesters, and mixtures thereof.

The polymer foam element may in some examples be only arranged within the compartment and may in certain embodiments thus not protrude from the compartment. In some embodiments, sole plate is a rigid sole plate. Typically, the hardness of the sole plate is between a Vickers Hardness (HV) 50 HV and 1 25 HV in particular between 75 HV and 100 HV (see for example Ghani et al "Hardness, Tensile and Microstructure Assessment of Carbon/Glass Hybrid Composite Laminate" J. Mechanical Engineering 2018, 1 5(2), 91 -105 and https://en.wikipedia.org/wiki/Vickers_hardness_test). In some embodiments, the hardness of the sole plate is greater than the hardness of the polymer foam element.

In some embodiments, the sole plate has anisotropic bending characteristics.

In some embodiments, the sole plate is made from polymeric materials, such as polyamide, polyether block amide (PEBAX), polyurethane. In certain embodiments, the sole plate comprises fiber materials, such as glass fibers or carbon fibers. In embodiments in which the top layer and the base layer are separate elements and thus not integrally formed, they may be made from different materials. For example, the top layer may comprise carbon or glass fibers and the bottom layer may only comprise a polymer material as described above without any fibers. Alternatively, the bottom layer may comprise carbon or glass fibers and the top layer may only comprise a polymer material as described above without any fibers.

Directional indications as used in the present disclosure are to be understood as follows: The longitudinal direction LO of the sole plate unit, respectively the shoe sole, is described by an axis from the heel area, respectively from the heel edge, to the forefoot region, respectively to the shoe sole tip/sole plate unit tip, and thus extends along the longitudinal axis of the sole plate unit or sole. Thus the term "extending along/in the longitudinal direction" typically refers to extending towards the shoe sole tip, respectively sole plate unit tip, and the term "extending against the longitudinal direction" typically refers to extending towards the heel edge. The transverse direction TR of the sole plate unit respectively the shoe sole, extends transversely to the longitudinal axis and substantially parallel to the ground in the operative state. Thus, the transverse direction runs along a transverse axis of the sole plate unit, respectively the sole. In the context of the present invention, the vertical direction V denotes a direction from the base layer to the top layer of the sole plate unit, or in the operative state in the direction of the foot of the wearer, and thus runs along a vertical axis of the sole plate unit, respectively the shoe sole. Thus the term "extending along/in the vertical direction" typically refers to

5 extending towards the top layer of the sole plate unit, respectively the sole, and the term "extending against the vertical direction" typically refers to extending towards the base layer of the sole plate unit, respectively the sole. The longitudinal direction, the vertical direction and the transverse direction may all be perpendicular to each other. The indication "horizontal" refers to a plane extending in the longitudinal and the transverse direction and0 being perpendicular to the vertical direction. The lateral side of the sole plate unit, respectively the sole, is the outer perimeter of the sole plate unit, respectively the sole between the heel edge and the shoe sole tip/sole plate unit tip, which in the worn state rests against the outer instep of the wearer's foot. The medial side of the sole plate unit, respectively the sole, refers to the inner perimeter of the sole plate unit, respectively the sole, between the heel edge and5 the shoe sole tip/sole plate unit tip, which is located opposite the lateral side. Thus, in a pair of worn running shoes, the medial sides of the two running shoes face each other and the lateral sides face away from each other. Furthermore, the sole plate unit, respectively the sole, may typically along the longitudinal direction be divided into a forefoot area, a heel area and a midfoot area being arranged between the forefoot area and the heel area. For example, the0 forefoot area extends from the shoe sole tip against, i.e. opposite, the longitudinal direction to 30-45% of the total length of the sole plate unit, respectively the sole, in the longitudinal direction. The heel area extends, for example, from the heel edge in the longitudinal direction to 20-30% of the total length of the sole plate unit, respectively the sole in the longitudinal direction. The midfoot area extends directly between the heel area and the forefoot area, such5 that the length in the longitudinal direction of the midfoot area makes up the remaining portion of the total length, particularly from 1 5-50% of the total length. In the vertical direction, the top layer is typically arranged above the base layer. Furthermore at least at some positions, the top layer is in the vertical direction spaced apart from the base layer thereby defining the compartment. However, this does not necessarily mean that the top layer and the base layer are arranged in the transverse direction directly above each other,

5 i.e. that they are in the transverse direction aligned. It is also possible that in the transverse direction, the top layer and the base layer may be completely or partially offset to each other. For example, the top layer may be arranged in the center of the sole plate unit, while the base layer may be medially and laterally offset to the center top layer.

In some embodiments, the length of the compartment, i.e. its extension along the longitudinal0 direction, is at least 30%, in particular at least 40%, in particular at least 50%, of the total length of the sole plate, i.e. its extension in the longitudinal direction. In certain examples, the length of the compartment may be between 1 20 mm and 220 mm, in particular between 1 55 mm and 185 mm.

The height of the compartment, i.e. its largest extension along the vertical direction, may in some embodiments be between 5 mm and 25 mm, in particular between 1 2 mm and 18 mm.

In some embodiments, the sole plate unit comprises only a single compartment being defined by the top layer and the base layer.

In some embodiments, at least the portions of the base layer and the top layer which define the compartment are continuously closed layers. Thus, at least the portions of the base layer0 and the top layer which define the compartment do not comprise any openings, respectively any through-holes. Such closed layers enhance the force transmission and therefore enable a more pronounced forward propelling effect. In particular, the compartment may in the plane defined by longitudinal and the vertical direction be completely circumferentially defined, respectively delimited or surrounded, by the base layer and the top layer. It is understood however that also in such embodiments it is possible that the compartment comprises a lateral and/or a medial opening.

In some embodiments, the polymerfoam element fills at least 50%, in particular at least 60%, in particular at least 75%, in particular at least 85%, in particular at least 90%, in particular at least 95%, in particular 100%, of the compartment volume. The polymer foam element within the compartment enables to provide a stable stand upon tread and further prevents a too extensive deformation of the sole plate, thereby avoiding energy loss.

In some embodiments, the base layer and the top layer define the compartment such that the compartment has a medial opening and/or a lateral opening for facilitating elastic deformation od the sole plate. Thus, on the lateral side and/or medial side of the sole plate unit, respectively when used in a shoe sole on the lateral side and the medial side, the sole plate defines a corresponding opening. It is understood that such openings may be partially, or depending on the embodiment, completely filled, respectively closed, by the foam element.

In some embodiments, the top layer and the base layer contact each other in a forefoot area of the sole plate unit. Optionally, the top layer and the base layer contact each other additionally in a midfoot area of the sole plate unit. In particular embodiments, the top layer and the base layer contact each other only in the forefoot area of the sole plate unit and optionally additionally in the midfoot area. Thus, in such embodiments, there are only two contact positions of the base layer and the top layer. In other embodiments, the base layer and the top layer contact each other only in the forefoot area, in particular only at the tip of the sole plate unit, respectively in a shoe sole at the sole tip.

In some embodiments, the top layer extends from a heel area of the sole plate unit through a midfoot area of the sole plate unit to a forefoot area of the sole plate unit. Thus, the sole plate unit is configured such that when it is part of a shoe sole, the whole foot of the wearer, including the heel, is arranged above the sole plate. In particular, only the top layer is arranged in the heel area. The base layer extends typically only from the forefoot area to the midfoot area. Thus, the base layer does typically not extend into the heel area.

In some embodiments, a heel section of the top layer in the heel area comprises one or more through-holes. In the heel area, the through holes provide for a reduced weight of the sole plate unit, which generally delays runner's fatigue while there is no significant loss in force transmission, as the large majority of the force is transmitted between the runner's foot and the sole plate in the midfoot and forefoot area.

In some embodiments, the sole plate is elastic, i.e. when being biased by bending, it returns into its original configuration. In some embodiments, the top layer and the base layer are itself incompressible. Being "itself" incompressible means that the thickness of the top layer or base layer is not reduced during running, i.e. when a male 80 kg runner with shoe size US 10 runs shoes having a shoe sole with a sole plate unit according to the invention. Obviously however, the distance between the base layer and the top layer can be reduced during running.

In some embodiments, the top layer and the base layer are configured such that upon tread, i.e. footfall, and/or rolling movement, i.e. the movement of the foot contacting the ground with the heel and subsequent rolling such that the toes contact the ground, the sole plate is elastically deformed. Furthermore, the top layer and the base layer are configured such that upon push-off the sole plate returns to its original configuration. The original configuration relates to the unbiased configuration of the sole plate, in particular the non-bent configuration. This allows to induce a forward propulsion and thus enables faster and more enduring running sessions.

In some embodiments, the top layer and the base layer are arranged above each other and are in the transverse direction aligned with each other and/or the top layer and the base layer are in a transverse direction partially or completely offset to each other. If the base layer and the top layer are in the transverse direction aligned with each other, they may typically completely overlap.

In some embodiments, the top layer and the base layer are in a transverse direction partially

5 or completely offset to each other. For example, the top layer may be arranged in the center of the sole plate unit, while the base layer may be medially and laterally offset to the center top layer. It is further possible that along the transverse direction, the base layer and the top layer only partially overlap. Embodiments in which the base layer and the top layer are in the transverse direction completely offset to each other, i.e. in which they do not overlap, have0 the advantage that the overall weight of the sole plate unit is reduced, which delays runner's fatigue. In embodiments in which the top layer is arranged in the center of the sole plate unit and the base layer extends medially and laterally offset to the top layer, the base layer forms two lobes, i.e. a medial lobe and a lateral lobe. Each of these lobes may only be connected to the top layer in the forefoot area. The lobes may each extend from the tip of the sole plate, respectively the sole plate unit, against the vertical direction and against the longitudinal direction towards, and preferably into, the midfoot area of the sole plate unit. The lobes are each configured as separate spring elements and provide for a forward propulsion.

In some embodiments, the base layer comprises a plurality of cleats and/or a plurality of cleat abutments being configured for mounting cleats to the sole plate unit. Cleat abutments may0 be configured for releasably connecting cleats to the base layer, in particular by force lock and/or form lock. For example, the cleat abutments may comprise a snap fit structure, a bayonet fit structure or the like, which corresponds to a corresponding structure on the cleat. The cleats typically face away from the top layer, i.e. they extend in the operative state towards the ground such that they can engage with the ground. In some embodiments, the polymer foam element defines one or more channels extending from a medial side to a lateral side of the sole plate unit.

A channel is to be understood as a void or recess which may typically be tubular in shape. Generally, a channel is wholly or partially defined by its channel walls except at the medial side opening and the lateral side opening. Typically, the channels are empty, i.e. filled with air which is in fluid connection with the environment. In particular, the channels may be open and continuous, i.e., a channel is preferably not a blind hole. Preferably, one channel, in particular all channels, of the sole plate unit extends continuously from the lateral side to the medial side. In preferred embodiments, several or all channels may extend substantially parallel to each other. In certain embodiments, the channels are regularly arranged to each other.

In some embodiments, the total portion of the open area of the sole plate unit, i.e., the total portion of the lateral sided and medial sided channel openings, may be less than the total portion of the closed area of the sole plate unit, i.e., the total portion of the outer side of the sole plate unit that does not include channels.

In some embodiments, the channels are arranged in series in the longitudinal direction. This does not preclude some, or even all, of the channels from being arranged offset from each other in the vertical direction. However, in certain embodiments, the channels are vertically aligned with each other and thus not offset to each other. It is understood that such embodiments also include embodiments, in which the sole plate unit or the sole is in the vertical direction bent between in the forefoot area, as it is common for running shoes. Preferably, no channel is arranged completely and/or partially one above the other in the vertical direction. The lateral sided open area of such a single channel is typically less than 20%, in particular less than 10%, in particular less than 5%, of the lateral sided closed are of the foam element. The medial sided open area of such a channel is typically less than 20%, in particular less than 10%, in particular less than 5%, of the medial sided closed are of thefoam element A foam element defining such channels allows for a stable stand and concomitantly for a certain cushioning and thus flexibility of the sole plate unit.

In some embodiments, the one or more channels are each defined by the polymer foam element and by the top layer and/or the base layer. Thus, the one or more channels may be delimited by the polymer foam element and by the top layer and/or the base layer. In particular, the channels may only be delimited by the polymer foam element and by the top layer and/or the base layer. Channels which are at least partially defined or delimited by the top layer and/or the base layer facilitate bending of the top layer, respectively the base layer, which in turn allows for a more efficient energy storage and release by the sole plate and thus increases the support of the runner. In some embodiments, the channels, in particular all channels are defined, respectively delimited by both the polymer foam element and the sole plate, in particular by both the polymer foam element and the top layer. In certain embodiments the channels, in particular all channels are defined, respectively delimited by only the polymer foam element and the top layer.

In some embodiments, a ratio of the open area of the sole plate unit, i.e., the total portion of the lateral sided and medial sided channel openings, to the total closed area of the polymer foam element, i.e., the total closed area of the outer side of polymer foam element that does not include channels, is between 3: 100 to 1 :10, in particular between 1 1 :200 to 3:40.

In some embodiments, the channels have in the cross-section in the longitudinal direction and perpendicular to the transversal direction a trapezoidal shape. In contrast to a circular shape, such channels show an optimized deformation behavior, since a unstable feeling is in contrast to circular channels avoided or at least decreased, while providing for a better cushioning. Preferably, the trapezoidal shape consists of two parallel sides and two non-parallel sides. The two parallel sides may for example extend in the longitudinal direction. In preferred embodiments, the two non-parallel sides are angled towards each other. In certain embodiments, one of the two parallel side is shorter than the other. Preferably the shorter one of the two parallel sides is arranged closer to the base layer of the sole plate. In other embodiments, the channels may be in the cross-section in the longitudinal direction and perpendicular to the transversal direction a triangular shape, a star shape or a cross-shape.

In some embodiments, each channel has a medial sided and a lateral sided channel opening, Each medial sided and lateral sided opening may define an open area of 20 mm ² to 1 60 mm ² , in particular of 35 mm ² to 90 mm ² .

In some embodiments, the base layer is concavely curved towards the top layer. In such embodiments, when viewed from the top layer on the base layer, the base layer forms a concavity. In some embodiments, the top layer is convexly curved to the base layer. In such embodiments, when viewed from the base layer on the top layer, the top layer forms a convexity towards the base layer. A concavely shaped base layer has the advantage that the propulsion effect is more horizontally forward directed and less vertically upward, which increases the runner's speed. In addition, a convexly shaped top plate evokes a facilitated bending during running and thus additionally increases the propulsion.

In some embodiments, the sole plate unit has a bending modulus, in particular as determined according to Test Method 1 , of 1 N/mm ² to 25 N/mm ² , in particular of 8 N/mm ² to 18 N/mm ² . Such a bending modulus has been found to provide sufficient cushioning and enables an optimal forward propulsion of the runner.

According to Test Method 1 , a 3-point bending test is performed (for the 3-point bending test see https://en.wikipedia.org/wiki/Three-point_flexural_test and DIN EN I SO 1 78:201 9). For this, a sole plate unit is positioned with its base layer on two support pins which extend over the complete transverse direction of the sole plate unit. The sole plate unit used may generally be a US size 10 sole plate and may have a length of 262 mm. The two support pins are spaced apart from each other with a distance of 180 mm. Each support pin has a width (extension along the transverse direction of the sole plate unit during the measurement) of 50 mm and has a rounded edge with a curve radius of 2 mm which supports the sole plate unit. Then a loading pin is arranged on the top layer at the position at which width of the sole plate unit, i.e. the extension in the transverse direction, reaches its maximum. The loading pin has a width (extension along the transverse direction of the sole plate unit during the measurement) of 50.4 mm and a rounded half cylindrical edge which pushes on the sole plate unit having a diameter of 10 mm. The loading pin is arranged in the longitudinal direction between the two support pins. The front support pin, i.e. the support pin which is closer to the tip of the sole plate unit is in the longitudinal direction spaced 60 mm apart from the loading pin; and the back support bin, i.e. the support pin which is arranged closer to the heel edge of the sole plate unit is in the longitudinal direction spaced 1 20 mm apart from the loading pin. Then, the loading pin is preloaded with a perforce of 10 N (F _o ) and then gradually loaded with a force which bends the sole plate unit and the force (Fi ) is measured which is required for deflect the sole plate unit by 10 mm in the vertical direction to measure the corresponding force (test speed: 50 mm/min). By the formula E = l ³ _v AF/(4D _L ba ³ ) the bending modulus can be determined, wherein AF is the difference in Newton between the end of the measurement (Fi) and the begin of the measurement (F _o ); l _v is the support span width in mm; D _L is the bending distance between Fi and F _o in mm; b is width of the sample at the position of the loading pin in mm and a is the thickness of the sample at the position of the loading pin in mm.

A second aspect of the invention relates to a shoe sole. The shoe sole comprises a sole plate unit according to any of the embodiments described herein, in particular with respect to the first aspect of the invention, a midsole being connected to the top layer of the sole plate unit and optionally an outsole. The midsole may be attached in the vertical direction above and/or below the top layer of the sole plate unit.

In some embodiments, the midsole may be made from a polymer, in particular a foamed polymer. Suitable materials include polyurethanes, in particular expanded polyurethane, polyamide, polyether block amides, polyethylene vinyl acetate (EVA), polyolefins, polyesters, and mixtures thereof.

The midsole may further define one or more channels extending from a medial side to a lateral side of the sole plate unit. These channels may also have a medial sided and a lateral sided opening. Such channels may be referred to as "midsole-channels". Furthermore, the midsolechannels may be defined or delimited by the midsole and optionally at least partially by the top layer of the sole plate unit. Preferably, the midsole-channels are only defined, respectively delimited, by the midsole and the top layer of the sole plate. Furthermore, in some embodiments, the midsole-channels may also have in the cross-section in the longitudinal direction and perpendicular to the transversal direction a trapezoidal shape, as described herein above in the different embodiments for the channels defined by the polymer foam element. In certain embodiments, the midsole-channels may be arranged in series in the longitudinal direction. In some embodiments, the midsole-channels and the channels defined by the polymer foam element may be arranged in series in the longitudinal direction.

In some embodiments, the shoe sole may comprise a fastening structure at the shoe sole tip which is configured to provide a form locking and/or force locking connection of the top layer and the base layer, which may in these embodiments be separate elements. In particular, the fastening structure may be configured to provide a compression force in the vertical direction on the base layer and the top layer, thereby pressing the top layer and the base layer onto each other. It is understood that this compression force acts along and against the vertical direction. In certain embodiments, the fastening structure may comprise two longitudinally extending bars defining a recess between them, wherein the top layer and the base layer are arranged within the recess. In some embodiments, the bars extend only along 2% to 30% of the length, i.e. the extension in the longitudinal direction, of the shoe sole, in particular along 2% to 20%, more particular along 2% to 10% along the length of the shoe sole. In certain embodiments, the fastening structure and in particular the longitudinally extending bars are made from an elastic material. In certain embodiments, the recess defined by the two bars has a thickness, i.e. extension in the vertical direction, which is smaller than the sum of the thickness of the top layer and the base layer. Due to the elastic material, the top layer and the base layer can be forced into the recess despite having a larger thickness, thereby deforming the fastening structure, respectively the bars, which provides for a force locking connection of the top layer and the base layer. The bars may have any suitable cross sectional shape, such as the shape of a circular segment, e.g. a half circle, or they may have a rectangular cross- sectional shape. The cross-sectional shape is the shape of the cross-section along a horizontal plane, i.e. a plane defined by the transverse and longitudinal direction of the sole plate unit. The fastening structure may be a separate element or it may be part of the midsole and/or outsole of the shoe sole.

The outsole may be attached to the midsole and/or to the base layer. It is understood that the outsole is typically arranged such that it directly contacts the ground during running. The outsole may for example completely extend along the longitudinal and/or transversal extension of the midsole or only along certain portions or sections thereof. The outsole is typically madefrom an abrasion resistant polymer material, i.e. a material which has a greater hardness than the midsole.

Brief description of the figures The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the invention described in the appended claims. The drawings are showing:

Fig. 1 a perspective view of a sole plate unit according to an embodiment of the invention;

Fig. 2 a side view of the sole plate unit of Fig. 1 ;

Fig. 3 a shoe sole with a sole plate unit according to an embodiment of the invention;

Fig. 4 a shoe sole with a sole plate unit according to another embodiment of the invention;

Fig. 5 a schematic bottom view of a sole plate unit according to another embodiment of the invention;

Fig. 6 a schematic side view of the sole plate unit of Fig. 5;

Fig. 7a, b a schematic representation of measuring the bending modulus according to

Test Method 1 ;

Fig. 8 a portion of a shoe sole with a sole plate unit according to another embodiment of the invention. Exemplary embodiments

Figure 1 shows sole plate unit 1 according to an embodiment of the invention. Sole plate unit 1 comprises integrally formed sole plate 2 which is generally manufactured as a single piece. As can be seen, sole plate 2 comprises, or consists of, top layer 21 and base layer 22, which are configured such that they define a compartment having a compartment volume between them. Polymer foam element 3 is arranged within this compartment and in this embodiment fills 100% of the compartment volume, i.e. it completely fills the compartment volume. Top layer 21 is arranged above base layer 22, i.e. it is in vertical direction V arranged above base layer 22. Along transverse direction TR, top layer 21 and base layer 22 are aligned with each other. As can be seen, the compartment defined by base layer 22 and top layer 21 is in the plane defined by the longitudinal direction LO and the vertical direction V completely circumferentially surrounded by base layer 22 and top layer 22, i.e. along this plane, the compartment is completely closed. However, the compartment comprises a medially sided opening (not visible, facing away from the viewer) and a laterally sided opening. Both the top layer 21 and the base layer 22 are continuously closed layers, i.e. they do not comprise and openings or through holes.

Figure 2 shows a side view on the lateral side of sole plate unit 1 shown in Fig. 1 . As can be seen, top layer 21 of sole plate 2 extends from the heel area HA through the midfoot area MA to the forefoot area FA. The heel area starts at heel edge 4 and ends at the beginning of the midfoot area MA. The forefoot area FA starts at the end of midfoot area MA and ends at sole plate unit tip 5. In contrast, the base layer 22 only extends from the forefoot area FA to the midfoot area MA, but does not extend into the heel area HA. Top layer 21 and base layer 22 contact each other at only two positions, namely at sole plate unit tip 5 and in midfoot area MA. Base layer 22 is concavely formed towards top layer 21 and top layer 21 is convexly formed towards base layer 22. Figure 3 shows a shoe sole 10 with a sole plate unit 1 according to another embodiment of the invention. In contrast to the embodiment on Fig. 1 , the sole plate unit 1 of shoe sole 10 depicted in Figure 3 comprises polymer foam element 3 which defines a plurality of channels 31 , 32 (only two channels are referenced for clarity reasons). These channels each extend from the medial side to the lateral side through the sole plate unit. In general, such channels may extend in parallel to each other. Channels 31 and 32 are not only delimited by polymer foam element 3 but also by top layer 21 (channel 31 and 32) and/or by base layer 22 (channel 31 ). Thus, in this embodiment, the compartment volume of the compartment being defined by top layer 21 and base layer 22 is not completely filled, but less than 100% with polymer foam element 3.

Shoe sole 10 further comprises a midsole, which in this embodiment comprises first midsole portion 1 1 a being arranged on and above top layer 21 of sole plate unit 1 and second midsole portion 1 1 b being arranged on and below top layer 21 of sole plate unit 1 . Lower midsole portion 1 1 b further defines, respectively delimits, a plurality of channels 1 1 1 (only one of these channels is references for clarity reasons). These channels are each further defined, respectively delimited, by top layer 21 which extends into the heel area of the shoe sole.

In addition, shoe sole 10 comprises outsole 1 2, which is arranged such that it contacts the ground during running. As can be seen, outsole 1 2 only covers certain portions of lower midsole portion 1 1 a, and also a portion of base layer 22 of sole plate unit 1 .

Fig. 4 shows a cross sectional view of shoe sole 10 according to another embodiment of the invention. This shoe sole comprises sole plate unit 1 with top layer 21 and base layer 22 defining a compartment. The compartment is almost completely filled with polymer foam component 3. However, polymer foam component 3, top layer 21 and base layer 22 define a channel 31 which extends from the medial side to the lateral side through the sole plate unit. Furthermore, base layer 22 comprises cleat abutments 221 which each engage and are releasably connected with a cleat 222 (only one cleat abutment and one cleat are referenced for clarity reasons). As can be seen, these cleats extend away from top layer 21 and in the operated state towards the ground during running. Furthermore, parts of top layer 21 in the heel area are covered by outsole 1 2. In addition, shoe sole 10 comprises midsole 1 1 which is arranged on and above top layer 21 of sole plate unit 1 .

Figure 5 shows a schematic view on base layer 22 of sole plate unit 1 according to another embodiment of the invention. Although also in this embodiment, the base layer and the top layer are in the vertical direction arranged above each other, they are in contrast to the embodiment shown in Fig. 1 and 2, in the transverse direction TR offset to each other and do only partially or not at all overlap. Top layer 21 is arranged in the center of sole plate unit 1 and base layer 22 forms, respectively consists of, two lobes 22a and 22b, wherein one lobe 22b is medially arranged with respect to the top layer and one lobe 22a is laterally arranged with respect to the top layer. Furthermore, while the portions of base layer 22 and top layer

21 which define the compartment are continuously closed layers, top layer 21 comprises a through hole 21 1 in the heel area, i.e. in a portion which does not define the compartment.

Fig. 6 shows a schematic side view of the embodiment of Fig. 5. As can be seen, base plate

22 is only connected in the forefoot area, in particular at tip 5 of sole plate unit 1 with top layer 21 . Lobe 22a extends against vertical direction V and against longitudinal direction LO and is spaced apart from top layer 21 defining a compartment which is filled by polymer foam element 3. In contrast to the embodiment of Fig. 1 and 2, base plate 22, respectively lobes 22a and 22b, is only connected at one position, i.e. at the tip 5 of sole plate unit 1 , with top layer 21 , but not in the midfoot area.

Fig. 7a and b show how the bending modulus according to Test Method 1 can be determined. Two support pins are spaced apart from each other with a distance of 180 mm and contact the base layer of the sole plate unit to be measured. Arranged between the two support pins is a loading pin which contacts the top layer of the sole plate unit. The loading pin has in the longitudinal direction a distance from the front support pin of 60 mm and to the back support pin a distance of 1 20 mm. Furthermore, as can be seen in Fig. 7a, the loading pin is arranged at the position at which the sole plate unit has in the transverse direction the largest width, i.e. at which the extension in the transverse direction reaches its maximum.

Fig. 8 shows an enlarged portion of a shoe sole 10 with midsole 1 1 , outsole 1 2 and sole plate unit 1 . In contrast to the sole plate unit shown in Fig. 1 , the sole plate unit 1 shown in Fig. 8 is not integrally formed, but top layer 21 and bottom layer 22 are separate pieces which are connected by force locking via fastening structure 6. Fastening structure 6 may in this or any other embodiment as described herein be part of the sole unit 1 or it may be part of the shoe sole 10. Fastening structure 6 comprises two longitudinally extending bars 61 and 62. As can be seen, the bars extend essentially in parallel to each other and define a recess between them. Top layer 21 and base layer 22 are inserted into this recess. Since bars 61 and 62 are formed from an elastic material and since the thickness of the recess, i.e. the distance of bars 61 and 62 in the vertical direction V to each other, is smaller than the sum of the thickness of top layer 21 and base layer 22, their insertion into the recess forces bars 61 and 62 apart from each other, thereby providing a vertically acting compression force, which provides a force-locking connection of top layer 21 and base layer 22.

List of Reference Signs

I sole plate unit

10 shoe sole

I I midsole

1 1 a first midsole portion

1 1 b second midsole portion 1 1 1 channel

1 2 outsole

2 sole plate

21 top layer

5 22 base layer

22a, 22b lobe

21 1 through hole

221 cleat abutment

222 cleat 0 3 polymer foam element

31 , 32 channel

4 heel edge

5 sole plate unit tip

6 fastening structure

61 , 62 bar

FA forefoot area

HA heel area

LO longitudinal direction

MA midfoot area 0 TR transverse direction

V vertical direction