Laterally and Medially Flexible Midsole

The present invention lies in the field of shoe technology and relates to a midsole for a sport shoe, such as running shoes or particularly gymnastic or cross-fit shoes, a shoe sole with such a midsole and a shoe with such a midsole or shoe sole shoes.

Soles for sport shoes typically comprise different cushioning systems. Relevant cushioning systems known in the prior art relate to channels which enable cushioning, spring elements, such a vertically extending dampers, or fluid filled chambers, e.g. chambers which are filled with a gel or with air. The majority of such cushioning systems focus on the forces which occur during long or medium distance running in which vertical acting forces predominate. In addition, when running downhill also forces acting horizontally, i.e. along a longitudinal direction of the shoe sole occur.

However, in other sports, in particular in cross-fit or gymnastics, the sportsperson does not only perform unidirectional movements as it is the case for long or medium distance running, but also other movements, such as side steps, jumps, lunges, squats and the like, which are not unidirectional, but also entail laterally or medially acting forces on the wearer's foot. Furthermore, as cushioning typically requires a certain degree of flexibility, many cushioning systems known in the prior art evoke instabilities, in particular in the medial and lateral directions. While this is not a significant issue for unidirectional running, it is a profound disadvantage for other activities as mentioned above, in particular as such instabilities may cause severe foot injuries.

In particular, for cross-fit or gymnastics a greater flexibility of the shoe for side step movements, splits and the like would be desirable.

Furthermore, as cushioning requires a certain flexibility, it typically leads to a less efficient force transmission. As an example, if a sportsperson jumps, not all of the body force is used for the push-off, as a certain part will be absorbed by the cushioning system. Therefore, it would be desirable not only to provide efficient cushioning, but also to allow for an efficient force transmission into the desired movement.

It is therefore the general object of the present invention to advance the state of the art of sole technology and preferably overcome the above mentioned disadvantages fully or partly. Preferably a midsole is provided which allows for a greater flexibility of the shoe for side step movements, splits and the like. In further advantageous embodiments, significant instabilities, in particular lateral or medial sided instabilities are avoided. In further advantageous embodiments, a midsole is provided which allows for a greater wearing comfort, in particular during side step movements.

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

The invention relates in a first aspect to a midsole for a sport shoe, in particular a gymnastic or cross-fit shoe. The midsole comprises a forefoot area, a heel area and midfoot area. The midfoot area is generally arranged between the forefoot area and the heel area. The midsole further comprises a top layer and an opposing, i.e. oppositely arranged, base layer. The top layer and the base layer typically delimit the midsole in the vertical direction. Furthermore, the midsole comprises a heel edge and a midsole tip. A longitudinal direction of the midsole extends from the heel edge to the midsole tip. It is understood that in the operative state, i.e. in the worn state, the toes of the wearer are arranged at the midsole tip, respectively towards the midsole tip, and the heel of the wearer is arranged at the heel edge, respectively towards the heel edge. The midsole further comprises one or more horizontal tilting slits. The one or more horizontal tilting slits are each arranged on a medial side of the midsole or on the lateral side of the midsole. It is understood however that there may be one or more horizontal tilting slits on the medial side and also one or more horizontal tilting slits on the lateral side of the midsole. Each of the horizontal tilting slits divide the midsole into a corresponding midsole top portion and a midsole base portion. The midsole top portion is in the vertical direction arranged above the horizontal tilting slit and the midsole base portion is in the vertical direction arranged below the horizontal tilting slit. Each horizontal tilting slit is configured to tilt the corresponding midsole top portion, i.e. the midsole top portion above this horizontal tilting slit, with respect to the corresponding midsole base portion, i.e. the midsole base portion being arranged below this horizontal tilting slit. During tilting, the corresponding horizontal tilting slit widens, i.e. a slit angle defined between the midsole top portion and the midsole base portion widens. This entails a higher flexibility of the midsole, in particular during side step movements or splits. Furthermore, as the slit is a horizontal slit, there is no profound instability of the midsole, e.g. in the medial and/or lateral direction.

Directional indications as used in the present disclosure are to be understood as follows: The longitudinal direction LO of the midsole, 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 midsole tip, and thus extends along the longitudinal axis of the midsole. Thus, the term “extending along/in the longitudinal direction” typically refers to extending towards the midsole tip and the term “extending against the longitudinal direction” typically refers to extending towards the heel edge. The transverse direction TR of the midsole respectively the shoe sole, extends transversely to the longitudinal axis and substantially parallel to the base layer of the midsole, or substantially parallel to the ground in the operative state. Thus, the transverse direction runs along a transverse axis of the midsole. In particular, the transverse direction extends from the medial side of the midsole to the lateral side of the midsole, respectively the shoe sole. Thus, the term “extending along/in the transverse direction” may typically refer to extending towards the lateral side of the midsole and the term “extending against the transverse direction” typically refers to extending towards the medial side of the midsole. In the context of the present invention, the vertical direction V denotes a direction from the base layer to the top layer of the midsole in the direction of the insole, or in the operative state in the direction of the foot of the wearer, and thus runs along a vertical axis of the midsole respectively the shoe sole. Thus, the term “extending along/in the vertical direction” typically refers to extending towards the top layer of the midsole and the term “extending against the vertical direction” typically refers to extending towards the base layer of the midsole. Furthermore, the terms “above” or “below” typically refer to an element being arranged in the vertical direction above or below another element. The longitudinal direction, the vertical direction and the transverse direction may all be perpendicular to each other. The lateral side of the midsole is the outer perimeter of the midsole between the heel edge and the sole tip, which in the worn state rests against the outer instep of the wearer's foot. The indication “horizontal” refers to a direction or plane extending in the longitudinal and the transverse direction and being perpendicular to the vertical direction. In the worn state, a horizontal tilting slit is thus parallel to the base layer, the top layer or also to the ground. The medial side of the midsole, refers to the inner perimeter of the midsole between the heel edge and the sole 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 midsole may typically along the longitudinal direction be divided into a forefoot area, a heel area and a midfoot area being arranged between the forefoot area and the heel area. For example, the forefoot area extends from the midsole tip against, i.e. opposite, the longitudinal direction to 30-45% of the total length of the midsole 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 midsole in the longitudinal direction. The midfoot area extends directly between the heel area and the forefoot area, such that the length in the longitudinal direction of the midfoot area makes up the remaining portion of the total length, particularly from 15-50% of the total length.

Typically, the one or more horizontal tilting slit is, or are each, configured to tilt the corresponding midsole top portion about a horizontal tilting axis with respect to the midsole base portion. The horizontal tilting axis may in particular extend in the longitudinal direction of the midsole.

In some embodiments, the midsole comprises a medial sided horizontal tilting slit and a lateral sided horizontal tilting slit. In particular embodiments, the midsole comprises only a single medial sided horizontal tilting slit and only a single lateral sided horizontal tilting slit. It is understood that a medial sided horizontal tilting slit is arranged on the medial side of the midsole and a lateral sided horizontal tilting slit is arranged on the lateral side of the midsole. Having such a single horizontal tilting slit on each side allows flexibility both for movements in the lateral and in the medial direction.

In some embodiments, the one or more horizontal tilting slits are arranged in the midfoot area of the midsole and optionally in the forefoot area. In particular embodiments, one or more horizontal tilting slits are arranged only in the midfoot area of the midsole. Such an arrangement has the advantage that a midsole is provided which is flexible for sideway movements, but whose heel area does not comprise such a horizontal tilting slit, which increases the stability of the midsole. This is advantageous, as in particular during running initial contact with the ground is conducted with the heel area and thus having horizontal tilting slits only in the midfoot and optionally the forefoot area increases the stability.

In embodiments, in which the midsole comprises only a single lateral sided horizontal tilting slit and only a single medial sided horizontal tilting slit, the distance between each of these horizontal tilting slits and the heel edge is between 20% and 40%, in particular between 25% and 35% of the total length of the midsole. The total length of the midsole is defined as the extension of the midsole from the heel edge to the midsole tip along the longitudinal direction.

In some embodiments, the one or more horizontal tilting slits each have a depth of 3 mm to 25 mm, in particular of 5 mm to 8 mm. The depth of a slit is the extension of the slit from the medial side or the lateral side in the transverse direction into the midsole. Thus, the depth of a medial sided horizontal tilting slit is the extension of this slit from the medial side in the transverse direction towards the lateral side of the midsole. Vice versa, the depth of a lateral sided horizontal tilting slit is the extension of this slit from the lateral side in the transverse direction towards the medial side of the midsole.

Typically, the horizontal tilting slits are not through slits, i.e. they do not extend completely in the transverse direction through the midsole, i.e. they do not extend completely from the medial side to the lateral side. Thus, the horizontal tilting slits extend in the transverse direction only partially through the midsole.

In some embodiments, the one or more horizontal tilling slits each have a depth which is 4% and 25%, in particular 5% and 12%, of a total width of the midsole at the position of the corresponding slit of the midsole.

In some embodiments, each horizontal tilting slit has a width, i.e. the distance between the midsole top portion being arranged above the corresponding horizontal tilting slit and the midsole base portion being arranged below the corresponding horizontal tilting slit which is 1.5 mm or less, in particular 1.0 mm or less. In certain embodiments, each horizontal tilting slit has a width which is between 0.3 mm to 1.5 mm, in particular between 0.5 mm and 0.7 mm.

In some embodiments, the ratio of the depth of the one or more horizontal tilting slits to the width of the one or more horizontal tilting slits is 5:1 to 20:1, in particular 7:1 to 16:1.

In some embodiments, the length of a horizontal tilting slit, i.e. its extension in the longitudinal direction, is between 50 mm and 200 mm, in particular between 80 mm and 120 mm.

In some embodiments, the midsole further comprises one or more tiltable blocks, wherein each tiltable block is partially defined by a horizontal tilting slit (i.e. by one of the horizontal tilting slits of the midsole), in particular by a single horizontal tilting slit. However, it is possible that a single, i.e. the same, horizontal tilting slit partially defines two or more tiltable blocks. Each of such tiltable blocks is typically arranged in the vertical direction above the corresponding horizontal tilting slit. Thus, each tiltable block is part of the corresponding midsole top portion. In particular, the corresponding midsole top portion consists of the corresponding tiltable blocks. Each tiltable block is typically tiltable with respect to the midsole base portion.

In some embodiments, the midsole comprises at least one tiltable block on the medial side and at least one tiltable block on the lateral side. In specific embodiments, the midsole comprises only a single tiltable block on the medial side and only a single tiltable block on the lateral side.

In some embodiments, each tiltable block is further defined by one or more sideward slits, wherein each sideward slit extends from the horizontal tilting slit to the top layer of the midsole. Typically, each sideward slit may merge with the horizontal tilting slit. Such sideward slits increase the flexibility of the tiltable block and thus increases the flexibility of the midsole. In such embodiments, a corresponding tiltable block is defined, respectively delimited, by the horizontal tilting slit and one or two sideward slits. Preferably, each sideward slit may only extend between the top layer and the horizontal tilting slit. Therefore, such sideward slits do not extend beyond the horizontal tilting slit, in particular not into the midsole base portion between the base layer and the horizontal tilting slit.

Each sideward slit may extend in the vertical direction, i.e. only in the vertical direction, respectively in parallel thereto, or may be inclined with respect to the longitudinal direction of the midsole.

In some embodiments, each sideward slit has a width which is 1.5 mm or less, in particular 1.0 mm or less. In certain embodiments, each sideward slit has a width which is between 0.3 mm to 1.5 mm, in particular between 0.5 mm and 0.7 mm.

In some embodiments, each of the sideward slits has a depth of 3 mm to 25 mm, in particular of 5 mm to 8 mm.

In some embodiments, at least some of the tiltable blocks have in the cross section along the longitudinal direction and perpendicular to the transverse direction a trapezoid shape, in particular a shape of a rectangle or a parallelogram.

In some embodiments, each of the one or more horizontal tilting slits is spaced apart from the base layer of the midsole and/or the top layer of the midsole by at least 20%, in particular by at least 30%, in particular by at least 40%, of the thickness of the midsole. The thickness of the midsole is the distance between the top layer and the base layer in the vertical direction at the corresponding position.

In some embodiments the midsole defines a plurality of recessed pockets which are open towards the top layer and wherein at least some of the recessed pockets are in the longitudinal direction arranged one after another.

In some embodiments, the recessed pockets are arranged in the forefoot area and. optionally in the midfoot area.

In preferred embodiments, the recessed pockets are separate recessed pockets. This means, each recessed pocket is separated and not connected with other recessed pockets. Typically, each of the separate recessed pockets is circumferentially delimited by wall portions. particularly vertically extending wall portions. These wall portions preferably completely delimit the recessed pockets in the plane defined by the transversal and the longitudinal direction. In certain embodiments, all vertically extending wall portions which define a given recessed pocket have the same height, i.e. extension in the vertical direction. However, it may in certain embodiments be possible that the height of vertically extending wall portions which define different recessed pockets have the same or different heights.

In some embodiments, the midsole comprises, respectively defines, a central notch extending in the longitudinal direction through the midfoot area and optionally from the forefoot area through the midfoot area to the heel area. The central notch is typically essentially arranged in the center of the midsole, i.e. in the transverse direction the notch has essentially the same distance to the medial side and to the lateral side of the midsole. Typically, the central notch vertically protrudes the midsole, i.e. it may be considered as a through hole in the vertical direction. Preferably, the central notch is horizontally circumferentially surrounded by the midsole. Embodiments with such a central notch provide for a higher flexibility of the midsole during lateral and medial movements, because tilting of the horizontal tilting slit is simplified. Particular embodiments with tiltable blocks as disclosed above and such a central notch are favorable, as the central notch increases the flexibility of the tiltable blocks.

In some embodiments, the central notch divides the midsole into a lateral portion and a medial portion. In certain embodiments, the lateral portion of the midsole comprises recessed pockets which are in the longitudinal direction arranged one after another and wherein the medial portion of the midsole comprises recessed pockets which are in the longitudinal direction arranged one after another. Preferably, the medial portion comprises a single row of recessed pockets being in the longitudinal direction arranged one after another and the lateral portion comprises a single row of recessed pockets being in the longitudinal direction arranged one after another.

In a second aspect, the invention relates to a shoe sole, in particular a shoe sole for a gymnastic or cross-fit shoe, which comprises a midsole as described herein, in particular with respect to the first aspect of the invention. The shoe sole further comprises an elastic plate being arranged on the top layer of the midsole.

In embodiments, in which the midsole comprises one or more recessed pockets as described herein, the elastic plate may optionally comprise a plurality of protrusions which are inserted into the recessed pockets of the midsole. The plate preferably comprises a plate body, e.g. a flat and/or even plate body from which the protrusions protrude. The elastic plate may be directly in contact with the midsole and it may in the vertical direction be arranged above the midsole. Particularly, the elastic plate is arranged in the operative, i.e. worn, state closer to the wearer's foot than the midsole. In particular, the elastic plate may be a rigid elastic plate. For example, the elastic plate may be incompressible. The skilled person understands that an elastic plate is a plate which when being bent, i.e. being biased, returns into its original shape. Preferably, each protrusion engages into a corresponding recessed pocket of the midsole. It has been observed that in such embodiments, the elastic recessed pocket and the elastic plate both deform upon landing, which provide for a cushioning effect. Additionally, the protrusion of the elastic plate in the correspondingly deformed recessed pocket is elastically deformed, i.e. biased. Upon push off, the protrusion returns to its original state which provides a propelling effect and thus enables an efficient force transmission.

In some embodiments, the elastic plate may be integrally formed, i.e. it may be single-pieced.

In some embodiments, each protrusion forms a bulge forming a convexity towards the midsole and in particular towards the base layer of the midsole. The bulge is configured such during running it is upon landing elastically compressed in a vertical direction of the sole and is further configured such that it returns to its original shape upon push off. This allows for a forwardly directed propulsion and thus improves the force transmission. The original shape refers thereby to the shape of the bulge in an unbiased, i.e. unstressed state.

In some embodiments, the elastic plate comprises several bulges which are transversally or longitudinally offset to each other. Preferably, always between two transversally or between two longitudinally offset bulges is an even section of the elastic plate. An even section is a section of the elastic plate, which in particular along the longitudinal direction, does not comprise a bulge but extends evenly. In particular, such an even section may be essentially parallel to the midsole top layer or the midsole base layer. Such sections increase the stability upon landing.

The elastic plate may typically have an essentially constant thickness. Thus, the bulge is typically not significantly thicker than the rest of the plate. For example, the elastic plate may have at each of the bulges a thickness which is at most 3×, in particular at most 2×, in particular at most 1.5× the thickness in other areas of the plate.

The bulge may in some embodiments be curved, and in particular be bell shaped. In other embodiments, the bulge may have in the cross section along the longitudinal direction and perpendicular to the transverse direction of the sole have a U-shape, a V-shape or trapezoidal shape.

In some embodiments, the elastic plate extends along at least 50%, in particular along at least 75%, in particular along at least 85%, in particular along at least 95% or even along 100% of the total width, i.e. the extension along the transverse direction, of the midsole.

In some embodiments, the elastic plate extends along at least 50%, in particular along at least 75%, in particular along at least 85%, in particular along at least 95% or even along 100% of the total length, i.e. the extension along the longitudinal direction, of the midsole.

In some embodiments, the elastic plate has a thickness between 0.5 mm and 3.0 mm, in particular between 0.9 mm and 1.2 mm.

In some embodiments, one or more of the protrusions are inserted into the central notch and preferably through the central notch. In certain embodiments in which more than one protrusion is inserted into the central notch, the protrusions may along the longitudinal direction be arranged one after another. Preferably, the protrusions may be aligned with the base layer, i.e. in the vertical direction, thereby avoiding that the protrusion protrudes from the base layer of the midsole. Such embodiments have the advantage that both the lateral and medial stability is increased. Furthermore, the protrusions being inserted into the slit may each form a bulge as described in the embodiments above, which in particular forms a convexity towards the midsole. Also, such a bulge is configured such that during running it is elastically compressed in a vertical direction of the sole upon landing and that it returns to its original shape upon push off. It is understood that a “notch” has typically a smaller width than a “slit” as used herein.

In some embodiments, the elastic plate has a greater hardness than the midsole. In some embodiments, the hardness of the elastic plate is between 60 Shore A and 100 Shore D, in particular between 70 Shore A to 100 Shore D.

The elastic plate may for example be made from a thermoplastic polyurethane, polyolefins, in particular polyethylene and polypropylene, polyester, polyester elastomers, polyamide, polyether block amide, carbon fiber and mixtures thereof. Additionally, the elastic plate may comprise reinforcement fibers for increasing the rigidity. These may for example be selected from linen, basalt, bamboo, hemp, cellulose, glass and carbon fibers as well as mixtures thereof.

A third aspect of the invention relates to a shoe, in particular a gymnastic or cross-fit shoe, which comprises a midsole according to any of the embodiments as described herein, in particular with respect to the first aspect of the invention, or, which comprises a shoe sole according to any of the embodiments as described herein, in particular with respect to the second aspect of the invention. The shoe further comprises an upper being attached to the midsole. The upper is preferably a textile upper, such a knitted upper or a non-woven upper. Typically, such an upper comprises a foot arch, i.e. the part of the upper which in the worn state extends over the foot arch of the wearer.

In some embodiments, the shoe further comprises a support mechanism which is connected to the midsole top portion or to several or all of the midsole top portions, which are arranged in the vertical direction above the one or more horizontal tilting slits of the midsole. Furthermore, the support mechanism extends over the foot arch of the upper. The support mechanism is configured to support tilting of the midsole top portion with respect to the midsole base portion. In particular, the support mechanism is configured such that laterally or medially forces acting on the upper are at least partially transmitted to the midsole top portion, respectively the multiple midsole top portions. Thus, upon performing a sidestep or the splits, a force acting towards the medial side may induce a pulling effect on the midsole top portion on the lateral side. Thereby, tilting is facilitated.

In some embodiments, the support mechanism comprises or consists of a plurality of straps. Such straps may for example each extend from a central region of the foot arch of the upper to a midsole top portion on the lateral side, which is in the vertical direction arranged above a lateral sided horizontal tilting slit and/or from the central region of the foot arch of the upper to a midsole top portion on the medial side, which is in the vertical direction arranged above a medial sided horizontal tilting slit.

shows midsolewhich can be used in a sports shoe. Midsolecomprises heel area HA, forefoot area FA and midfoot area MA which is arranged between heel area HA and forefoot area FA. Furthermore, midsolecomprises heel edgeand midsole tip. The longitudinal direction LO of midsoleruns from heel edgeto midsole tip. Midsolefurther comprises top layerand thereto oppositely arranged base layer. Top layerand base layermay for example generally define the vertical delimitation of midsole. The vertical direction V extends from base layerto top layerand is essentially perpendicular to the longitudinal direction LO.shows the lateral side of midsole. Midsolefurther comprises horizontal tilting slitbeing arranged in midfoot area MA, which as can be seen extends in the longitudinal direction LO and also against transverse direction TR of midsole, i.e. it is arranged in a horizontal plane of midsole. It is understood that such a horizontal plane is defined by the longitudinal direction LO and the transverse direction TR. Horizontal tilting slithorizontally divides midsolein midsole top portionwhich is the part of the midsole being in the vertical direction V arranged above horizontal tilting slitand into midsole base portionwhich is the part of the midsole being in the vertical direction V arranged below horizontal tilting slit. Thus, midsole top portionand midsole base portionare in the vertical direction V arranged above each other and are spaced apart from one another by horizontal tilting slit. Horizontal tilting slitis configured such that midsole top portioncan be tilted with respect to midsole base portion. Horizontal tilting slitallows midsole top portionto be tilted about a horizontal tilting axis which extends in the longitudinal direction LO.

Midsolefurther comprises, respectively defines, sideward slits,,and. These slits are connected to horizontal tilting slit. However, in contrast to horizontal tilting slit, which may in general preferably extend essentially in parallel to midsole top layerand/or to midsole base layer, sideward slits,,andeach extend from horizontal tilting slitto top layer. Thus, each sideward slit has also a vertical component, i.e. it extends also in vertical direction V. Midsolefurther comprises tiltable blocks,,andwhich are defined against the vertical direction V by horizontal tilting slitand on the sides by one or more sideward slits,,and. For example, tiltable blockis defined by horizontal tilting slitand by sideward slitsand. Tiltable blockis defined horizontal tilting slitand by sideward slitsand. Tiltable blockis defined by horizontal tilting slitand by sideward slit. Each tiltable block is tiltable, in particular tiltable with respect to midsole base portion. The tiltable block form together the midsole top portion. Tiltable blocksandhave a trapezoidal shape.