MIDSOLE UNIT

Description

BACKGROUND OF THE INVENTION

Field Of The Invention

The present invention lies in the field of shoe technology and particular in the field of trail running shoes, The invention relates to a midsole unit and a shoe with such a midsole unit which are particularly suitable for trail running.

Discussion of Related Art

Trail running has recently gained more and more attention in the field of running sports. In contrast to street running sports, trail running is conducted on unpaved trails. Often, trail running is performed in the mountains and, depending on the steep gradients, combined with hiking Trails range from broad and relative well maintained dirt roads to narrow and rocky mountaineering paths.

Due to the significant difference of the trails in trail running as compared to paved streets, the requirements for a trail running shoe differ vastly to a street running shoe. For example. the rough terrain requires a more stable and abrasion resistant outsole. Furthermore, larger stone plates may be slippery and therefore an anti-slipping sole is more important for trail running shoes than for street running shoes.

Due to the often uneven and rocky terrain, it is of utmost importance for preventing injuries that the runner receives a detailed feedback of the ground surface as otherwise injuries due to twisting ankles or slipping may occur. In certain shoes this is achieved by providing a very thin sole, which may for example have a thickness of less than 1 cm or even less than 0.7 cm. While such soles may provide an Immediate and detailed feedback to the runner about the current terrain, they often suffer from being able to provide a stable stand and sufficient cushioning.

SUMMARY OF THE INVENTION

It is therefore a general object of the present invention to advance the state of the art of shoes, in particular trail running shoes, and preferably to overcome the disadvantages mentioned above fully or partly. Preferably, a midsole unit and a shoe is provided which provides high tactile feedback to the runner but at the same time provides a stable stand and therefore avoids injuries such as ankle twisting, and/or provides sufficient cushioning during running

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 midsole unit for a shoe, in particular a trail running shoe. The midsole unit comprises a midsole and optionally a rigidifying structure. The midsole has a top layer and a base layer. The top layer is oppositely arranged to the base layer, e.g. vertically oppositely arranged to the base layer, The top layer and the base layer typically delimit the midsole in the vertical direction and thus define in the vertical direction the outer periphery of the midsole. Furthermore, the midsole defines, respectively comprises, a plurality of base layer grooves, which extend at the base layer of the midsole. The midsole comprises further a plurality of block elements which are at least partially defined and separated from each other by the plurality of base layer grooves. That is, the base layer grooves are arranged between the block elements, in particular between adjacent block elements. The midsole further defines a plurality of top layer grooves, which extend at the top layer of the midsole. The grooves allow for individual deformation of the block elements. Thus, if the runner steps on a stick or an edge of a rock, the deformation occurs locally only at the corresponding block elements which are in contact with the stick or edge. Thereby, the runner receives a detailed and immediate feedback about the current terrain. This functionality is enhanced by the top layer grooves, which simplify the deformation of the block elements by allowing their extension by decreasing the width of an adjacent top layer groove. In addition, the rigidifying structure decreases the flexibility of the sole and therefore increases the stability, Thereby, a stable stand is provided and injuries such as ankle twisting are diminished or avoided. The rigidifying structure acts together with the block elements, base layer grooves and top layer grooves. The grooves enable the individual deformation of a specific block element, which increases the runner's feel of the ground conditions, However this may in some instances lead to an undesired form of flexibility, because the midsole may become too flexible which may entail an unstable stand. In order to prevent this but still maintain the increased runner's feel of the ground, the rigidifying structure is provided.

A groove as used herein is a depression in the midsole. Typically, a groove is thus vertically open. That is, a base layer groove is a depression in the midsole at the base layer which is open towards the base layer and therefore in the worn state preferably open towards the ground. Vice versa, a top layer groove is a depression in the midsole at the top layer which is open towards the top layer and therefore in the worn state preferably open towards the foot of the wearer. Open towards the ground or the foot of the wearer does however not mean that the groove is necessarily uncovered. It may well be that the groove may be covered by other elements, such as an outsole or an insole. However, the groove is in the vertical direction not fully surrounded or delimited by the midsole. This is different to a channel which may in the vertical direction be fully delimited and surrounded by the midsole.

Directional indications as used in the present disclosure are to be understood as follows: The longitudinal direction L of the midsole, respectively the shoe, 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 T 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 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. 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. 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 midsole tip, which in the worn state rests against the outer instep of the wearer's foot. The indication “horizontal” refers to a plane extending in the longitudinal and the transverse direction and being perpendicular to the vertical direction. 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. Thus a medially arranged element is an element being arranged at the medial side of the midsole and a laterally arranged element is an element being arranged at the lateral side of the midsole. 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, Le, 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.

It is generally understood herein that the term “comprising” is interpreted as meaning that it includes those features following this term, but that it does not exclude the presence of other features, as long as they do not render the claim unworkable. On the other hand, if the wording “consist of” is used, then no further features are present in the corresponding apart from the ones following said wording.

In some embodiments, the rigidifying structure is arranged on top of the top layer. That is, the rigidifying structure is in direct contact with the top layer. The top layer may in the vertical directions therefore be arranged between the rigidifying structure and the base layer, In such embodiments, the rigidifying structure is arranged in close proximity to the wearer's foot, which is particularly advantageous for providing a stable stand. If such a midsole unit is used in a shoe in certain embodiments of the invention, the rigidifying structure is in the operative, i.e. worn, state preferably arranged closer to the wearer's foot than the base layer and/or the midsole. In particular embodiments, the midsole defines a recess at the top layer and the rigidifying structure is inserted within this recess, in particular such that the rigidifying structure is aligned with the top layer.

In some embodiments, the midsole may be made from a single piece, in particular, the midsole may be molded, e.g. foam molded.

In some embodiments, each block element is configured and/or arranged such that it can be individually deformed, in particular if a force acts only on the corresponding block element.

In some embodiments, the block elements are elastic and/or viscoelastic block elements.

In some embodiments, each block element has a surface area at the base layer of the midsole of 1 cm² to 25.0 cm², in particular 2.5 cm² to 25.0 cm² in particular of 3.5 cm² to 11.5 cm²

In some embodiments, the rigidifying structure is arranged such that it decreases torsion of the midsole along the longitudinal direction and/or such that it decreases bending, i.e. the bendability, of the midsole along the transverse direction of the midsole, i.e. about an axis in the transverse direction.

The rigidifying structure may have anisotropic bending characteristics, e.g. it bends more easily along a bending axis extending in the transverse direction than along a bending axis in the longitudinal direction. It is clear that the rigidifying structure has a higher rigidity than the midsole and has a rigidifying effect on the midsole unit. The rigidifying structure is typically in itself incompressible and elastic.

In some embodiments, the rigidifying structure is arranged such that it is arranged offset to the plurality of block elements. In particular it is arranged such that it is arranged offset to all of the plurality of block elements or to at least some, e.g. the majority, of the plurality of block elements. The term “offset” means that when viewed along the vertical direction, i.e. from the base layer towards the top layer, there is no overlap between the rigidifying structure and the block elements. Particularly, the rigidifying structure is arranged longitudinally offset and/or transversally offset with respect to the plurality of block elements. For example, the rigidifying structure may be arranged between two or more of the block elements, in particular only between two or more block elements. Preferably however, the rigidifying structure is in the vertical direction not arranged directly above or below the block elements. Embodiments in which the rigidifying structure is offset to the block elements have the advantage that the rigidifying structure does not hamper the deformation of a specific block element and therefore a force acting on a specific block element can be transmitted efficiently to the runner's foot, which increases the runner's feel of the ground conditions but at the same time increase the stability of the midsole and enables a secure stand.

In some embodiments, the rigidifying structure is arranged such that it separates two or more of the plurality of block elements from each other.

In some embodiments, the rigidifying structure is arranged in at least a portion of the base layer grooves. In particular, the rigidifying structure may only be arranged in portions of the base layer grooves.

In some embodiments, the rigidifying structure is arranged between the top layer and the base layer of the midsole. In particular, the plurality of block elements may protrude further away from the top layer than the rigidifying structure.

In some embodiments, the rigidifying structure extends over at least a portion of the top layer grooves or of the base layer grooves. Additionally, or alternatively, the rigidifying structure covers at least a portion of the top layer grooves or of the base layer grooves, Thereby the deformation behavior of the corresponding block elements being defined by these grooves is varied as compared to other block elements. This may for example stabilize certain regions of the midsole, for example the midfoot area and thereby decrease the risk of injuries due to ankle twisting.

In some embodiments, the rigidifying structure comprises, or consists of, a plate, such as an elastic and/or rigid plate. In some embodiments, the rigidifying structure comprises, or consists of, one or more rods, such as elastic and/or rigid rods. In some embodiments, the rigidifying structure comprises, or consists of, a foil, such as an elastic and/or rigid foil.

The rigidifying structure may in some embodiments have a hardness which is greater than the hardness of the midsole, in particular at least 5% greater, in particular at least 10% greater, in particular at least 20% greater, in particular at least 40% greater, in particular at least 50% greater, in particular at least 75% greater, in particular at least 100% greater, than the hardness of the midsole. The hardness may for example be measured as Asker C hardness or as a Shore hardness.

In some embodiments, the rigidifying structure has a hardness of 50 Shore D to 80 Shore D, in particular of 60 Shore D to 70 Shore D

In some embodiments, the midsole structure has a hardness of 40 Asker C to 60 Asker C, in particular of 45 Asker C to 50 Asker C.

In some embodiments, the midsole unit has a bending modulus as determined by Test Method 1 of at least 3.0 N/mm² , in particular at least 3.5 N/mm², more particular at least 3.9 N/mm². In some embodiments, the midsole unit has a bending modulus as determined by Test Method 1 of at most 7.5 N/mm², in particular at most 6.5 N/mm², more particular at most 5.3 N/mm², Such a bending modulus provides a stable stand and an efficient push-off.

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 ISO 178:2019). For this, a midsole unit is positioned with its base layer on two support pins which extend over the complete transverse direction of the midsole unit. The midsole unit used may generally be a US size 10 midsole unit and may have a length of 262 mm. The two support pins are spaced apart from each other with a distance of 160 mm. Each support pin has a width (extension along the transverse direction of the midsole unit during the measurement) of 70 mm and has a rounded edge with a curve radius of 25 mm which supports the midsole unit. Then a loading pin is arranged on the top layer at 70% of the total length of the midsole unit measured from the heel edge to the midsole tip. The loading pin has a width (extension along the transverse direction of the midsole unit during the measurement) of 70 mm and a rounded half cylindrical edge which pushes on the midsole unit having a curve radius of 25 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 midsole unit is in the longitudinal direction spaced 80 mm apart from the loading pin (measured from the poles of the pins); and the back support bin, i.e. the support pin which is arranged closer to the heel edge of the midsole unit is in the longitudinal direction spaced 80 mm apart from the loading pin (measured from the poles of the pins). All three pins are arranged on a longitudinal center line of the midsole unit. i.e. the extension of each pin in the transverse direction towards the lateral peripheral edge and towards the medial peripheral edge is essentially the same. Then, the loading pin is preloaded with a preforce of 10 N (F₀) if a midsole unit is tested or with a preforce of 25 N (F₀) if a whole shoe with an upper is tested and then gradually (5 times) loaded with a force which bends the midsole unit and the force (F₁) is measured which is required for deflect the midsole unit by 15 mm in the vertical direction to measure the corresponding force (test speed: 300 mm/min). By the formula E=1³_vΔF/(4D_Lba³) the bending modulus can be determined, wherein ΔF is the difference in Newton between the end

of the measurement (F₁) and the begin of the measurement (F₀): l_v is the support span width in mm: D_L is the bending distance between F₁ and F₀ 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.

In some embodiments, the rigidifying structure, and in particular the plate, may comprise one or more legs. Preferably, the one or more legs extend in one or more base layer grooves. The one or more legs typically extend in or against the longitudinal and /r the transverse direction of the midsole.

In some embodiments, the rigidifying structure comprises a main body. In certain embodiments, the one or more legs may extend away from the main body.

In some embodiments, the rigidifying structure comprises, or has, a y-shape or a Y-shape.

In some embodiments, the rigidifying structure comprises a peripheral outer section which is curved. It is understood that the peripheral outer section of the rigidifying structure refers to the outer periphery of the rigidifying structure. Such embodiments are particularly advantageous, since the rigidifying structure follows the anatomic shape of the foot, in particular at the arch of the foot, which allows significantly improve the stability of the midsole unit.

In some embodiments, the rigidifying structure is arranged in a forefoot and/or in a midfoot area of the midsole. In particular embodiments, the rigidifying structure is only arranged in the forefoot and/or midfoot area. Thus, the rigidifying structure is in such embodiments preferably not arranged in a heel area of the midsole. The rigidifying structure and its rigidifying function is typically most important in the forefoot and heel area, because it is during the rolling motion and the push-off motion, when an instable midsole is disadvantageous and may lead to injuries.

In some embodiments, the rigidifying structure has a maximum length, in particular along the longitudinal direction of the midsole unit of 2 cm to 10 cm, in particular 2 cm to 7.5 cm, more particular of 2 cm to 5 cm.

In some embodiments, the rigidifying structure is arranged in the center of the midsole, In particular, at least portions of the rigidifying structure may be arranged along a longitudinal center axis of the midsole. The longitudinal center axis of the midsole extends in the longitudinal direction and separates the midsole in the lateral area and the medial area.

In some embodiments, the ratio of a surface area of the rigidifying structure to the total surface area of the base layer or the top layer of the midsole is 2:25 to 1:5, in particular 1:10 to 7:50. The surface area of the rigidifying structure refers only to the surface area facing towards the base layer,

In some embodiments, the midsoles comprise at least 8 block elements, in particular at least 10 block elements, more particular at least 15 block elements, more particular at least 20 block elements. In certain embodiments, the midsole comprises 8 to 30 block elements, io particular 10 to 25 block elements, in particular 15 to 25 block elements.

In some embodiments, the plurality of base layer grooves comprises, or consists of. a plurality of transverse base layer grooves which extend each in the transverse direction of the midsole. Furthermore, the plurality of base layer grooves may comprise, or consist of, one or more longitudinal base layer grooves, which extend in the longitudinal direction of the midsole. In certain embodiments, the base layer grooves may comprise only a single longitudinal base layer groove. The one or more longitudinal base layer grooves may extend from the heel area of the midsole through the midfoot area into the forefoot area of the midsole. In some embodiments, the one or more longitudinal base layer grooves may each have a width that is larger than the width of each of the plurality of transverse base layer grooves. It is understood that the height of a groove extends in the vertical direction. The length of a groove and the width of the groove are perpendicular to each other and perpendicular to the height of the groove. The length of the groove is measured along the direction the groove extends and is typically larger than the width and/or the height of the groove.

In some embodiments, the transverse base layer grooves and/or the longitudinal base layer grooves may for straight, in particular linear. Additionally or alternatively, the transverse base layer grooves and/or the longitudinal base layer grooves may be curved, in particular wave shaped.

Although this may in some embodiments be the case, the transverse base layer grooves do not necessarily have to extend linearly, but they may also be curved. A transverse base layer groove comprises a medial groove end and a lateral groove end. The medial groove end is arranged closer to the medial side of the midsole/midsole unit than the lateral groove end. It may for example be the case that the transverse base layer groove extends linearly between the medial and lateral groove end or that it extends in a curved manner between the medial and lateral groove

In some embodiments, the plurality of top layer grooves comprises, or consists of. a plurality of transverse top layer grooves which extend each in a transverse direction of the midsole. Preferably, the transverse top layer grooves, e.g. each transverse top layer groove, extend from a medial side of the midsole to a lateral side of the midsole. Thus, in such embodiments, the transverse top layer grooves may in the transverse direction extend completely through the midsole. In some embodiments, the plurality of top layer grooves comprises, or consists of, one or more longitudinal top layer grooves, which extend in the longitudinal direction of the midsole. In certain embodiments, the top layer grooves may comprise only a single longitudinal top layer groove. The one or more longitudinal top layer grooves may extend from the heel area of the midsole through the midfoot area into the forefoot area of the midsole. In some embodiments, the one or more longitudinal top layer grooves may each have a width that is larger than the width of each of the plurality of transverse top layer grooves. It is understood that the height of a groove extends in the vertical direction. The length of a groove and the width of the groove perpendicular to each other and perpendicular to the height of the groove. The length of the groove is measured along the direction the groove extends and is typically larger than the width and/or the height of the groove.

In some embodiments, the transverse top layer grooves and/or the longitudinal top layer grooves may for straight, in particular linear. Additionally, or alternatively, the transverse. top layer grooves and/or the longitudinal top layer grooves may be curved, in particular wave shaped.

Although this may in some embodiments be the case, the transverse top layer grooves do not necessarily have to extend linearly, but they may also be curved. A transverse top layer groove comprises a medial groove end and a lateral groove end. The medial groove end is arranged closer to the medial side of the midsole/midsole unit than the lateral groove end. It may for example be the case that the transverse top layer groove extends linearly between the medial and lateral groove end or that it extends in a curved manner between the medial and lateral groove end.

In some embodiments at least some or all of the transverse base layer grooves are aligned with a transverse top layer groove. This means the corresponding transverse base layer groove is arranged in the vertical direction below a corresponding transverse top layer groove and therefore not offset to it. In other words, the transverse base layer grooves are oppositely arranged to the transverse top layer grooves.

In some embodiments, the one or more longitudinal base layer groove is aligned with a longitudinal top layer groove. This means the corresponding longitudinal base layer groove is arranged in the vertical direction below a corresponding longitudinal top layer groove and therefore not offset to it. In other words, the longitudinal base layer groove is oppositely arranged to the longitudinal top layer groove.

In some embodiments, the rigidifying structure is arranged in the one or more longitudinal base layer grooves, respectively in at least a portion thereof.

In some embodiments, at least one or each of the one or more longitudinal base layer grooves branches into two longitudinal base layer Such a branching may be a direct branch in the longitudinal base layer groove, e. g. a y-shaped or Y-shaped branching, or it may alternatively be formed from two longitudinal base layer grooves being connected with each other by at least a portion of a transverse base layer groove.

Preferably, the plurality of base layer grooves comprises only a single longitudinal base layer groove which branches into two longitudinal base layer grooves. In preferred embodiments, the rigidifying structure comprises two legs which each extend in one of the branching longitudinal base layer grooves.

In some embodiments at least one of the longitudinal base layer grooves extends completely through the midsole, in particular from the heel edge to the midsole tip of the midsole. This means a first end of the longitudinal base layer groove is an opening in the periphery of the midsole, e.g. in the heel section and particular at the heel edge, and a second end of the longitudinal base layer groove is an opening in the periphery of the midsole, e.g. in the forefoot section and in particular at the midsole tip. Such a longitudinal base layer groove which extends completely through the midsole greatly enhances the individual deformability of the corresponding block elements being defined by this groove. Thereby, the runner's feel for the ground conditions is improved.

In some embodiments, at least one or all of the transverse base layer grooves which extend in the transverse direction, extend linearly between a medial groove end and a lateral groove end. The medial groove end and the lateral groove end typically define the beginning and the end of the corresponding groove. In some embodiments, the medial groove end and the lateral groove end have the same distance to a straight transverse line being tangential to the midsole's heel edge. Such a tangential line extends in the transverse direction and is thus perpendicular to the longitudinal direction. Such grooves are advantageous, in particular if arranged in the midfoot and/or forefoot area, because they allow easy bending of the midsole unit during running, which helps to decrease runner's fatigue.

In some embodiments, at least one of the transverse base layer grooves is arranged in the heel area of the midsole and particularly intersects at least one of the one or more longitudinal base layer grooves. Since the width of the heel is much smaller than the width of the forefoot area of the human foot, it is beneficial to further divide the heel area into multiple block elements, which are defined by such a trans base layer groove. This increases the runner's feel for the ground conditions in an area of the foot whit a small width and thus an area being prone effect twisting on uneven ground. If such transverse base layer grooves also intersect a longitudinal base layer groove, a finer segmentation of the base layer in multiple block elements is achieved and thus the runner's feel for the ground conditions is further improved.

In some embodiments, two of the block elements form together a medially arranged arch section which is delimited by the medial periphery of the midsole and which is further delimited by an arched base layer groove. This arched base layer groove extends from a first medial groove end to a second medial groove end of this groove. The second medial groove end is arranged closer to the midsole tip than the first medial groove end. In particular embodiments. the medially arranged arch section consists of these two block elements. The arched base layer groove typically extends from the first medial groove end towards the lateral side of the midsole to an apex and from there back to the second medial groove end. Such a medially arranged arch section is advantageous as it follows the human anatomy in the arch region of the foot.

In particular embodiments, the two block elements which form together the medially arranged arch section are separated from each other by a transverse base layer groove extending in the transverse direction of midsole. Thereby, the medially arranged arch section consists of two block elements which are independently deformable and therefore the feel for the ground of the runner in this area is significantly increased.

In some embodiments, the midsole defines an arched top layer groove being oppositely arranged to the arched base layer groove and extending at the top layer. Typically, the arched top layer groove extends from a first medial groove end to a second medial groove end of this arched top layer groove. The second medial groove end is arranged closer to the midsole tip than the first medial groove end.

In some embodiments, the top layer grooves are along a vertical direction of the midsole aligned with at least some of the base layer grooves. That is, in the vertical direction there is at least one pair consisting of a top layer groove and a base layer groove which are aligned with each other, i.e. arranged above each other. In other words, the corresponding base layer groove is oppositely arranged to the corresponding top layer groove. In particular, the top layer grooves are along a vertical direction of the midsole aligned with at least some of the transverse base layer grooves. Preferably, the majority (i.e, more than 50%) or even each base layer groove, particularly each transverse base layer groove, is aligned with one top layer groove. In embodiments in which the top layer grooves are aligned with the base layer grooves, the corresponding block element can more efficiently transmit the force of an impact, such as the impact of the edge of a stone to the foot of the wearer.

In some embodiments, the top layer grooves are along a vertical direction of the midsole offset with at least some of the base layer grooves, in particular the transverse base layer grooves. In particular, the top layer grooves are along a vertical direction of the midsole offset with all of the base layer grooves, in particular with all of the transverse base layer grooves. Such embodiments have the advantage that the cushioning function provided by the top layer grooves and base layer grooves is more evenly distributed over the midsole.

In some embodiments, the plurality of block elements are massive block elements. This means, the block elements consist of the midsole material, e.g. polymer foam material, and are therefore not hollow.

In some embodiments, the plurality of block elements are grouped into a medial group and lateral group of block elements. The medial group of block elements contains medially arranged block elements and the lateral group contains laterally arranged block elements. The medially arranged block elements are separated from the laterally arranged block elements.

In some embodiments, the medially arranged block elements are in the longitudinal direction arranged one after another. However, it is understood that these block elements are separated and spaced apart from each other by corresponding base layer grooves, i.e. transverse base layer grooves. Accordingly, the laterally arranged block elements are in the longitudinal direction arranged one after another, Also, here it is understood that these block elements are separated and spaced apart from each other by corresponding base layer grooves, i.e. transverse base layer grooves.

In some embodiments, the rigidifying structure is arranged between at least some of the medially arranged block elements and at least some of the laterally arranged block elements. This means, the rigidifying structure separates in these embodiments the corresponding medially arranged block elements from the corresponding laterally arranged block elements.

In some embodiments, the plurality of block elements are not only grouped into a lateral group and a medial group of block elements but also into a central group of block elements. The central group of block elements contains one or more centrally arranged block elements. Centrally arranged block elements are in the transverse direction typically arranged between medially arranged block elements and laterally arranged block elements.

In some embodiments, the number of block elements in the central group of block elements is less than the number of block elements in the lateral or medial group of block elements, For example, the number of block elements in the central group of block elements may be only up to 40% of the number of block elements in the lateral or medial group of block elements.

In certain embodiments, the rigidifying structure is arranged between the centrally arranged block elements and medially arranged block elements and/or the rigidifying structure is arranged between the centrally arranged block elements and laterally arranged block elements. In particular embodiments one leg of the rigidifying structure is arranged between the centrally arranged block elements and medially arranged block elements and/or one leg of the rigidifying structure is arranged between the centrally arranged block elements and laterally arranged block elements.

In some embodiments, the centrally arranged block elements are only arranged in the forefoot region and optionally in the midfoot region, preferably only in the forefoot region.

In some embodiments, the top layer grooves extend in parallel to the transverse base layer grooves.

In some embodiments, the midsole may comprise, or consist of, a midsole material. The midsole material is typically a polymer material, preferably a polymer foam material. In some embodiments, the midsole material is a thermoplastic material. Typical midsole materials include polyamide, polyether block amide, polyurethane, polyester or polyolefins.

In some embodiments, the midsole unit further comprises an outsole. The outsole may be attached to the base layer of the midsole. While in some embodiments, the outsole may be continuous and/or cover the whole base layer of the midsole. it may in some embodiments also be sectioned into different sections, which cover only portions of the midsole. For example, the outsole may cover some or all of the plurality of block elements.

In some embodiments, the height of each base layer groove, i.e. its extension in the vertical direction V of the midsole is between 3.0 mm to 12.0 mm, in particular 5.0 mm to 10 mm.

In some embodiments; the width of each base layer groove, i.e. its extension in the vertical direction V of the midsole is between 3.0 mm to 30.0 mm, in particular 5.0 mm to 10.0 mm.

In some embodiments, the ratio between the thickness of the midsole, i.e. the distance between the top layer and the base layer in the vertical direction, and the height of each top layer groove is 5:2 to 15:2, in particular 7:2 to 11:2.

In some embodiments. the height of each top layer groove, i.e. its extension in the vertical direction V of the midsole is between 2.0 mm to 9.0 mm, in particular 4.0 mm to 7.0 mm.

In some embodiments, the width of each top layer groove, i.e. its extension in the vertical direction V of the midsole is between 3.0 mm to 30.0 mm, in particular 6.0 mm to 12.0 mm.

In some embodiments, the ratio between the thickness of the midsole, i.e. the distance between the top layer and the base layer in the vertical direction, and the height of each base layer groove is 2:1 to 13:2, in particular 5:2 to 7:2.

In some embodiments, the ratio between the width of a transverse base layer groove and the length of an adjacent block element is between 1:10 to 7:10, in particular 1:5 to 2:5. Such a ratio is advantageous, as it allows to efficiently transmit the impact force of an object onto the. corresponding block element to the foot sole of the runner and therefore increases the runner's feel of the ground conditions. However, it also allows for providing sufficient stability of the midsole unit, which prevents injuries, such as ankle injuries.

A second aspect of the invention relates to shoe, in particular a trail running shoe, comprising the midsole unit according to any of the embodiments as described herein, in particular with respect to the first aspect of the invention.

In some embodiments, the shoe comprises in addition to the midsole unit an outer shoe. The outer shoe comprises an upper and an outer shoe outsole which together define a compartment. The midsole unit is releasably inserted into this compartment. Typically, the compartment and the midsole unit may be configured such that after insertion of the midsole unit the compartment provides space to accommodate the foot of a wearer. The term “releasably” means that the midsole unit can be multiple times inserted and removed, without altering the structural integrity of the midsole unit and/or the outer shoe. In particular, removing the midsole unit from the outer shoe does therefore not comprise the destruction of the midsole unit and/or the outer shoe. The midsole unit may thus be considered as an insert. When the midsole unit is inserted into the compartment, the upper and the outer shoe outsole surround the midsole unit. However, it is clear that the upper defines an opening into the compartment through which the midsole unit and the wearer's for can be inserted into the compartment.

In some embodiments, the midsole unit of the shoe has a bending modulus as determined by Test Method 1 of at least 3.0 N/mm², in particular at least 3.5 N/mm², more particular at least 3.9 N/mm². In some embodiments, the midsole unit has a bending modulus as determined by Test Method 1 of at most 7.5 N/mm², in particular at most 6.5 N/mm², more particular at most 5.3 N/mm². Such a bending modulus provides a stable stand and an efficient push-off.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

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.

FIG. 1 shows a schematic view onto the lateral side of a shoe with a midsole unit according to an embodiment of the invention;

FIG. 2 shows a schematic view from below onto the base layer of a midsole unit according to another embodiment of the invention;

FIG. 3 shows a schematic view from above onto the top layer of a midsole unit according to another embodiment of the invention;

FIG. 4 shows a schematic cross-sectional view of a shoe according to another embodiment of the invention;

FIG. 5 shows a schematic cross-sectional view of a shoe according to another embodiment of the invention;

FIG. 6a shows a measurement setup for the 3-point bending test according to Text Method 1;

FIG. 6b shows a schematic view where the loading pin is arranged in the setup shown in FIG. 6a;

FIG. 7a shows a schematic view onto the top layer of a midsole unit according to another embodiment of the invention;

FIG. 7b shows a schematic cross-sectional view of a midsole unit according to another embodiment of the invention; and

FIG. 7c shows a schematic view onto the base layer of a midsole unit according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a shoe 100 with midsole unit 1. Midsole unit 1 comprises midsole 2 having a top layer 3 and a base layer 4 which are in the vertical direction V distanced from each other and delimit the midsole 2 in vertical direction V. Midsole 1 is divided into a heel area HA. forefoot area FA and midfoot area MA being arranged directly between the heel area and the forefoot area.

Midsole 2 defines a plurality of base layer grooves 5a-5c (only three of the grooves are referenced for clarity purposes), which extends at the base layer 4 of the midsole. This means, the base layer grooves are in vertical direction V open towards the base layer 4, respectively they are accessible from the base layer 4. Furthermore, midsole 2 defines a plurality of top layer grooves 7a, 7b, 7c (only three of the grooves are referenced for clarity purposes) which extend at top layer 3 of midsole 2. This means, the top layer grooves are in vertical direction V open towards the top layer 3, respectively they are accessible from the top layer 3. Midsole 2 may preferably further comprise a rigidifying structure, which is not shown in FIG. 1.

Midsole 2 further comprises a plurality of block elements 6d, 6e (for clarity purposes only two block elements are referenced in FIG. 1), which are at least partially delimited and/or defined and separated from each other by the base layer grooves. For example, block element 6d is defined by base layer grooves 5a and 5b and separated from adjacent block element be by base layer groove 5b.

In this embodiment, the top layer grooves are along vertical direction V aligned with the base layer grooves. For example, top layer groove 7a is aligned with base layer groove 5a, top layer groove 7b is aligned with base layer groove 5b and top layer groove 7c is aligned with base layer groove 5c. If for example a sharp rock is only in contact with one block element, such as block element 6e, top layer grooves 7b and 7c together with base layer grooves 5b and 5c allow block clement de to deform separately when the impact force of the sharp rock acts on the block element and to efficiently transmit this impact to the runner's foot sole, thereby increasing the feel of the current ground conditions and improving the feedback to the runner.

Midsole unit 1 further comprises outsole 11, which is attached to at least portions of base layer 4 of midsole 2.

FIG. 2 shows a schematic bottom view of a midsole unit 1 according to another embodiment of the invention. FIG. 2 shows the view along the vertical direction V onto base layer 4 of the midsole. Midsole 2 defines a plurality of base layer grooves 5a, 5b. 5c, 5d, 5e, and 5f (for clarity purposes only these x grooves are referenced). These base layer grooves all define a plurality of elastic block elements, such as elastic block elements 6a, 6b, 6c, 6d, 6e, 6f, 6g and 6h (for clarity purposes only these eight block elements are referenced). The base layer grooves comprise a plurality of transverse base layer grooves 5a, 5b and 5c (only these three transverse base layer grooves are referenced for clarity purposes) which each extend in the transverse direction T of midsole 2. As can be seen, these transverse base layer grooves extend completely from the medial side to the lateral side of the midsole. Additionally, the plurality of base layer grooves comprises longitudinal base layer groove 5d. In this embodiment, longitudinal base layer groove 5d commences at the heel edge 12 and extends through the heel area into the midfoot area. In the midfoot area, longitudinal base layer groove 12 branches into two longitudinal base layer grooves 5e and 5f which may particularly extend into the forefoot area of midsole 2. Together, the transverse base layer grooves and the longitudinal base layer grooves define and separate block elements 6a-6g from each other, Midsole unit 1 further comprises rigidifying structure 8, which may for example be a plate or a foil. It can be seen that rigidifying structure 8 is arranged such that it is arranged offset with respect to the plurality of block elements 6a-6h. In the view onto base layer 4 of midsole 2 along vertical direction V, as shown in FIG. 2, there is no overlap between rigidifying structure 8 and any block element 6a-6h. In particular, rigidifying structure 8 is only arranged between elastic block elements 6a-6h. It can be seen that rigidifying structure 8 is fully arranged in some of the base layer grooves. Preferably, the rigidifying structure 8 is in this or any other embodiment as described herein arranged, in particular only arranged, in one or more longitudinal base layer grooves.

Rigidifying structure 8 further comprises two legs 9 and 10 which are arranged in base layer grooves. In particular, leg 9 is arranged in longitudinal base layer groove 5e and leg 10 is arranged in longitudinal base layer groove 5f. These legs extend away from a main body of the rigidifying structure.

The plurality of block elements of midsole 2 are in this embodiment grouped into three different groups of block elements, namely a medial group of block elements, such as block elements 6d, 6e and 6f, which are arranged in a medial area of the midsole (medially arranged), a lateral group of block elements, such as block elements 6a, 6b and 6c, which are arranged in a lateral area of the midsole (laterally arranged) and a central group of block elements, such as block elements of and 6h, which are arranged in the center of midsole 2 (centrally arranged). The centrally arranged block elements are in the transverse direction T arranged between laterally arranged block elements and medially arranged block elements (see for example 6g between 6c and 6f). Within each group, the block elements are arranged one after the other, but are separated from each other by one of the transverse base layer grooves. For example, medially arranged block elements 6d is arranged behind medially arranged block element Ge and is separated therefrom by transverse base layer groove 5b.

FIG. 3 shows midsole unit 1 according to another embodiment of the invention as a top view against the vertical direction of the midsole and on top layer 3 of midsole 2. As can be seen, midsole 2 defines a plurality of top layer grooves 7a-7f (only six top layer grooves are referenced for clarity purposes) which extend at the top layer of midsole 1. That is, these grooves Open towards the top layer and thus to the viewer. The plurality of top layer grooves comprises transverse top layer grooves, such as transverse top layer grooves 7a, 7b and 7c, which extend in the transverse direction of midsole 2 and which completely extend through the midsole, i.e. from its medial side to its lateral side. In addition, the plurality of top layer grooves comprises longitudinal top layer groove 7d which commences in the heel area and extends to the midfoot area of midsole 2. In this or any other embodiment disclosed herein, the longitudinal top layer groove 7d may branch in two longitudinal top layer grooves 7e and 7f, in particular in the midfoot area. The two longitudinal top layer grooves 7e and 7f may then extend into the forefoot area of midsole 2.

FIG. 4 shows another embodiment of a shoe 100′. This shoe comprises also a midsole unit 1 according to any of the embodiments described herein having a midsole 2 and rigidifying structure 8. However, in this embodiment, shoe 100′ comprises outer shoe 101, which itself comprises outer shoe outsole 103 and upper 102. Upper 102 and outer shoe outsole 103 together form a compartment into which midsole unit 1 is releasable inserted, Midsole unit 1 is further covered by insole 104 which may also be releasably inserted into the compartment. Such embodiments have the advantage that the beneficial effect of increasing the user feel is still achieved, however the outer shoe protects the midsole unit and particularly prevent stones and sticks from being caught in the base layer grooves or the top layer grooves.

FIG. 5 shows another embodiment of a shoe 100″, which is similar to the shoe shown in FIG. 1. In the following only the difference between the shoe 100″ shown in FIG. 5 and the shoe 100 shown in FIG. 1 are discussed. Midsole unit 1 of shoe 100″ also comprises top layer grooves 7a-7c (for clarity purposes, only three grooves are referenced) and base layer grooves 5a-5e, which define and separate block elements 6d and 6e of midsole 2 (for clarity purposes only two block elements and three base layer grooves re referenced). However, In this embodiment, top layer grooves 7a-7c are not aligned with base grooves 5a-5e, but are offset to base layer grooves 5a-5e. Therefore, above base layer groove 5a is no top layer groove, but it is in the longitudinal direction L offset to it.

FIG. 6 a shows the measurement setup for the 3-point bending test according to Test Method 1. As can be seen, the two support pins are spaced apart from each other by 160 mm (measured from the poles of the half cylinders). Further, the loading pin is arranged in the middle of the two support pins, i.e. 80 mm from both support pins (also measured from the poles of the half cylinders). Each of the three pins has a half cylindrical top portion with a radius r of 25 mm. FIG. 6b shows schematically where the loading pin is arranged. The total length of the midsole unit in the longitudinal direction is 100%. The loading pin is arranged at 70% of the total length. measured from the heel edge of the midsole unit. Furthermore, the loading pin is arranged on the side of the foot of the wearer in the worn state, i.e. at the side of the top layer of the midsole, FIG. 7a shows a schematic top view on top layer 3 of a midsole of a sole unit 1 according to another embodiment of the invention. As can be seen, sole unit 1 comprises midsole 2 and rigidifying structure 8. The latter is in this embodiment arranged on top layer 3 of midsole 2. In this or any other embodiment described herein, rigidifying structure 8 may be in direct contact with top layer 3 of midsole 2. Rigidifying structure 8 has in this embodiment a y-shape and comprises two legs 9 and 10 which branch off, respectively protrude, from the main body of rigidifying structure 8. Further, peripheral medial outer section 81 and peripheral lateral outer section 82 is curved. For example, it is in general possible that peripheral medial outer section 81 is concavely curved and/or that peripheral lateral outer section 82 which is oppositely arranged to the peripheral medial outer section is convexly curved. Such a structure is advantageous since it follows the anatomy of the human foot and provides a balance between ground feedback and a stable stand. Midsole 2 defines multiple grooves 7a to 7h which extend at top layer 3. It can be seen that midsole 2 defines longitudinal top layer groove 7d which extends from the heel area HA into the midfoot area MA. In midfoot area MA longitudinal top layer groove 7d branches into two longitudinal top layer grooves 7e and 7f. In this embodiment, this branching occurs via a section of transverse top layer groove 7e which connects longitudinal top layer grooves 7f and 7e. The longitudinal top layer grooves may in general be curved as it is shown for 7d, 7e and 7f. Midsole 2 additionally defines transverse top layer grooves 7a-7c and 7g which all extend in the transverse direction T and which are arranged behind each other. The transverse top layer grooves may in general intersect the longitudinal top layer grooves. The same may in some embodiments apply for the transverse base layer grooves and the longitudinal base layer grooves (see FIG. 7c). Transverse top layer grooves 7b and 7c have at all positions the same distance to straight transverse line t being tangential to the heel edge of midsole 2. In other words, these grooves extend in the transverse direction linearly between their corresponding medial groove end and their corresponding lateral groove end. The medial groove end and the lateral groove end have the same distance to straight transverse line t being tangential to the midsole's heel edge. In contrast, transverse groove 7g forms a curve between its medial groove end and its lateral groove end. Furthermore, midsole 2 defines arched top layer groove 7h which may in particular be arranged opposite to a corresponding arched base layer groove (see groove Si in FIG. 7c). In other words, arched top layer groove 7h may in the vertical direction be aligned with a corresponding arched base layer groove of midsole 2.

It can further be seen that rigidifying structure 8 extends over and covers a portion of transverse base layer channel 7b and of longitudinal top layer channel 7d. Thereby laterally arranged block element 6s and centrally arranged block clement 6g are functionally connected with each other via rigidifying structure 8.

FIG. 7 b shows a schematic cross-sectional view of a sole unit 1 according to an embodiment of the invention. It can be seen that midsole 2 comprises top layer 3 and oppositely arranged base layer 4. There are top layer grooves extending at top layer 4 and base layer grooves extending at base layer 4 (see FIGS. 7a and 7c). Importantly, it can for example be seen that transverse base layer groove 7b is covered by rigidifying structure 8. Furthermore, midsole 2 defines a recess at top layer 3 and rigidifying structure 8 is inserted into this recess. In particular it may generally in this or any other embodiment described herein be possible that rigidifying structure 8 is aligned with top layer 3 i.e. it does not protrude from top layer 3.

FIG. 7c shows a schematic view on base layer 4 of midsole 2 of a midsole unit 1 according to an embodiment of the invention. The base layer shown may be the base layer to midsole 2 shown in FIG. 7a. Midsole 2 defines a plurality of grooves, namely three longitudinal base layer grooves 5d, 5e and 5f as well as five transverse base layer grooves 5a to 5c, 5g and 5h as well as arched base layer groove 5i. It can be seen that longitudinal base layer grooves 5d and 5e together extend completely trough midsole 2. That is, they form an opening in the periphery of the midsole, i.e. in the heel section and in the forefoot section. Furthermore, longitudinal base layer groove 5d extends from the heel edge in the heel area HA into the midfoot area MA. In midfoot area MA longitudinal base layer groove 5d branches into two longitudinal base layer grooves 5e and 5f. In this embodiment, this branching occurs via a section of transverse base layer groove 5e which connects longitudinal base layer grooves 5f and 5e. The transverse base layer grooves may in general intersect the longitudinal base layer grooves. Transverse base layer grooves 5b and 5c have at all positions the same distance to straight transverse line t being tangential to the heel edge of midsole 2. In other words, these grooves extend in the transverse direction linearly between their corresponding medial groove end and their corresponding lateral groove end. The medial groove end and the lateral groove end have the same distance to straight transverse line t being tangential to the midsole's heel edge. In contrast, groove 5g forms a curve between its medial groove end and its lateral groove end.

In general, the transverse base layer grooves and the transverse top layer grooves define a plurality of block elements, such as medially arranged block elements 6d and 6e. The two block elements 6d and be form together a medially arranged arched section. This arched section is delimited by medial periphery 21 of midsole 2 and arched base layer groove 5i. Arched base layer groove 5i extends from its first medial groove end 51 which is arranged at medial periphery 21 of midsole 2 towards its second medial groove end 52 which is also arranged at medial periphery 21 of midsole 2 but which is closer to midsole tip 22 than first medial groove end 51. When extending between first medial groove end 51 and second medial groove end 52, arched base layer groove 5i extends towards the lateral side of midsole 2 and forms an apex before it returns to second medial groove end 52. Block elements 6d and 6e which form together the medially arranged arched section are spaced apart and separated from each other by transverse base layer groove 5b which allows a higher flexibility and deformability of these block elements,