ARTICLE OF FOOTWEAR WITH FLEXIBLE SOLE STRUCTURE

Abstract

An article of footwear disclosed herein has various features especially advantageous for outdoor use, such as for hiking. The article of footwear has a sole structure that includes a plate extending in a forefoot region of the sole structure. The plate defines a longitudinal slot extending through the plate and a transverse slot intersecting with the longitudinal slot and also extending through the plate. The longitudinal slot and the transverse slot both terminate inward of an outer perimeter of the plate and together defining four quadrants of the plate.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application No. 63/750,081, filed Jan. 27, 2025, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to an article of footwear, and more specifically to an article of footwear with a flexible sole plate and/or other features.

BACKGROUND

Footwear typically includes a sole structure configured to be located under a wearer's foot to space the foot away from the ground or floor surface. A sole structure can be designed to provide a sufficient level of cushioning, support, and traction for a particular athletic endeavor.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only, are schematic in nature, and are intended to be exemplary rather than to limit the scope of the disclosure.

FIG. 1 is a medial side view of an article of footwear including a footwear upper and a sole structure.

FIG. 2 is a lateral side view of the article of footwear.

FIG. 3 is a front view of the article of footwear.

FIG. 4 is a rear view of the article of footwear and showing a heel counter in hidden lines within the footwear upper.

FIG. 5 is a plan view of a midsole included in the sole structure of the article of footwear.

FIG. 6 is a plan view of a plate included in the sole structure of the article of footwear.

FIG. 7 is a plan view of the plate of FIG. 6 received on a foot-facing surface of the midsole of FIG. 5.

FIG. 8 is a plan view of the sole structure included in the article of footwear of FIG. 1 including the plate and midsole of FIG. 7 and showing an outsole included in the sole structure.

FIG. 9 is a cross-sectional view of the midsole of FIG. 5 taken at lines I-I in FIG. 5 to show drain passages extending through the midsole.

FIG. 10 is a cross-sectional view of an alternative midsole showing an alternative configuration of drain passages.

FIG. 11 is a plan view of the midsole of FIG. 5 with an alternative plate for the sole structure included in the article of footwear of FIG. 1.

FIG. 12 is a plan view of the plate of FIG. 11.

FIG. 13 is a perspective view of an alternative plate for the sole structure included in the article of footwear of FIG. 1.

FIG. 14 is a bottom view of the sole structure included in the article of footwear of FIG. 1.

FIG. 15 is a bottom view of the midsole of FIG. 5.

FIG. 16 is a cross-sectional view of the sole structure included in the article of footwear of FIG. 1 taken at lines II-II in FIG. 8.

FIG. 17 is a cross-sectional view of the sole structure included in the article of footwear of FIG. 1 taken at lines III-III in FIG. 8.

FIG. 18 is a cross-sectional view of the sole structure included in the article of footwear of FIG. 1 taken at lines IV-IV in FIG. 8.

FIG. 19 is a perspective view of the outsole of the sole structure included in the article of footwear of FIG. 1.

FIG. 20 is a rear view of the heel counter included in the article of footwear of FIG. 1.

FIG. 21 is a midsole layer of an alternative midsole for the sole structure of the article of footwear of FIG. 1.

FIG. 22 is another midsole layer for use with the midsole layer of FIG. 21 in the alternative sole structure of the article of footwear of FIG. 1.

FIG. 23 is a bottom view of the midsole layers of FIGS. 21 and 22 assembled together as a midsole.

FIG. 24 is a lateral view of the midsole of FIG. 23.

FIG. 25 is a cross-sectional view of the midsole of FIG. 23 taken at lines V-V in FIG. 23.

FIG. 26 is a front view of the midsole of FIG. 23.

FIG. 27 is an exploded view of the alternative sole structure including the midsole of FIGS. 21-26, the alternative plate of FIG. 12, and the outsole of FIG. 19.

DESCRIPTION

An article of footwear disclosed herein has one or more features specifically configured to enhance comfort and control when worn outdoors, such as on uneven terrain, for downhill treks, and through wet conditions.

An article of footwear disclosed herein has various features especially advantageous for outdoor use, such as for hiking. The article of footwear has a sole structure that includes a plate extending in a forefoot region of the sole structure. The plate defines a longitudinal slot extending through the plate and a transverse slot intersecting with the longitudinal slot and also extending through the plate. The longitudinal slot and the transverse slot both terminate inward of an outer perimeter of the plate and together defining four quadrants of the plate. In this manner, the plate affords protection to a wearer's foot in the forefoot region of the article, such as by shielding rough terrain, including rocks. Additionally, the longitudinal and transverse slots enable the plate to flex in multiple directions, helping to ensure stable footing on rough terrain. For example, the four quadrants of the plate are shaped and dimensioned to flex relative to one another both under dorsiflexion of the sole structure and under torsional forces on the sole structure.

In an aspect, a medial end of the transverse slot may be forward of a lateral end of the transverse slot. For example, the transverse slot may be generally linear, angling rearward from the medial side to the lateral side, and may be positioned to underlie an expected location of the metatarsal phalangeal joints of the wearer and, more specifically, a bending axis of the foot at the metatarsal phalangeal joints. As such, the transverse slot makes it easier for the plate to flex during dorsiflexion of the wearer's foot in comparison to a plate of the same size without the transverse slot.

In another aspect, the transverse slot may be wider at its medial and/or lateral terminus to reduce stress concentrations and further increase flexibility. For example, the transverse slot may have a middle segment that intersects with the longitudinal slot and may have a lateral terminus and a medial terminus with the middle segment between the lateral terminus and the medial terminus. Either or both of the lateral terminus and the medial terminus may have a greater fore-aft width than the middle segment.

Other components of the sole structure may be configured in a manner complementary to the plate to further enhance the flexibility of the sole structure. For example, the sole structure may include a midsole that has an inner surface with at least one of a recess or a protrusion configured as a locating feature adapted to receive the plate. Stated differently, the inner surface may include either or both of the recess or the protrusion. In an aspect, the midsole may include an elongated transverse recess in the inner surface. The elongated transverse recess may underlie the transverse slot. In an implementation, the elongated transverse recess may be a medial transverse recess that underlies a medial end segment of the transverse slot, and the midsole may further include an elongated lateral transverse recess that underlies a lateral end segment of the transverse slot. Such an implementation allows a plate having the medial end segment, a lateral end segment, and a middle segment as discussed above to be easily located and positioned relative to the midsole during assembly.

The sole structure may also be configured to assist with draining and expelling water from the footwear as may be advantageous when hiking through puddles, creeks, etc. For example, the midsole may define a drain passage extending through the midsole from an entrance opening of the drain passage at the elongated transverse recess to an exit opening of the drain passage. The exit opening may be at an outer surface of the midsole, such as at a side wall portion or a bottom portion of the midsole. By placing the entrance opening at the transverse recess of the midsole, dorsiflexion of the midsole may help to move water through the drain passage and out of the exit opening. For example, as the sole structure is dorsiflexed, because the elongated transverse recess may be disposed generally in alignment with the metatarsal phalangeal joints as discussed above, the midsole may resiliently compress and/or expand at the drain passage, helping to move water that pools in the transverse recess through the drain passage and out of the midsole.

In an implementation, the midsole may also include a medial flex groove and a lateral flex groove in an outer surface of the midsole that extend transversely inward at a bottom portion of the outer surface from a medial side wall portion of the outer surface and a lateral side wall portion of the outer surface, respectively. The medial and lateral flex grooves further increase flexibility of the midsole. In an aspect, the flex grooves may be aligned with and underlie the transverse recess of the midsole. In an embodiment having a drain passage as discussed above at both the medial and lateral end segments of the transverse recess, the medial and lateral flex grooves may be in alignment with the exit openings of the drain passages.

In an aspect, the sole structure may include an outsole secured to the outer surface of the midsole. The outsole may be configured to complement the features of the midsole discussed above. For example, the outsole may have a medial side wall, a lateral side wall, and an underfoot portion extending from the medial side wall to the lateral side wall. The outsole may have a medial notch in the medial side wall of the outsole. The medial notch may extend into the underfoot portion of the outsole and underlie the medial flex groove of the midsole. Alternatively or in addition, the outsole may include a lateral notch in the lateral side wall of the outsole. The lateral notch may extend into the underfoot portion of the outsole and may underlie the lateral flex groove of the midsole. In this manner, the notch or notches of the outsole further enhance the flexibility of the sole structure at the lateral flex groove of the midsole. Additionally, the notch(es) of the outsole may be in alignment with the exit opening(s) of the drain passage(s) to expose the exit opening(s) on the midsole so as not to create a barrier to water expulsion.

In another aspect, the midsole may include a longitudinal groove in an outer surface of the midsole. The longitudinal groove may extend from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole. Such a longitudinal groove increases flexibility of the midsole, such as by enabling increased relative movement of a medial portion of the midsole relative to a lateral portion of the midsole in the forefoot region. This may help to increase traction on uneven terrain. In an aspect, the longitudinal groove of the midsole may underlie and be aligned with the longitudinal slot of the plate. In this manner, the longitudinal groove of the midsole and the longitudinal slot of the plate are cooperatively configured to enhance flexibility of the sole structure.

In an implementation, the outer surface of the midsole may include a convex medial portion disposed at a medial side of the longitudinal groove and extending substantially from the longitudinal groove to a medial side wall of the midsole and from an anterior portion of the forefoot region of the midsole to the midfoot region of the midsole. The outer surface of the midsole may further include a convex lateral portion disposed at a lateral side of the longitudinal groove and extending substantially from the longitudinal groove to a lateral side wall of the midsole and from the anterior portion of the forefoot region of the midsole to the midfoot region of the midsole. For example, the convex medial portion and the convex lateral portion of the outer surface of the midsole may each have a separate convex profile at a transverse cross-section of the midsole. Such a configuration enables separate contact and grip of the convex medial and lateral portions with an uneven ground surface, similar to a cloven hoof.

In implementations of the sole structure that include an outsole secured to the outer surface of the midsole, the outsole may have a bifurcated forefoot portion defining a longitudinal split that underlies the longitudinal groove of the midsole. The midsole may be exposed at the longitudinal split of the outsole. In this manner, the outsole further enhances the flexibility of the sole structure at the longitudinal groove of the midsole.

In another aspect, the article of footwear may include a footwear upper that is secured to the sole structure and defines a foot-receiving cavity over the sole structure. The outsole may include a toe shield portion that wraps upward onto a toe portion of the footwear upper. In an aspect, the longitudinal split of the outsole may continue through the toe shield portion. The outsole thus protects that toe portion of the footwear upper without adversely affecting flexibility of the outsole along the longitudinal split.

In an implementation, the midsole may include multiple layers, such as layers having different hardnesses. In implementations, in which the midsole comprises foam, the layers may have different densities. For example, the midsole may include a first midsole layer that includes the at least one of a recess or a protrusion configured as a locating feature adapted to receive the plate, and a second midsole layer having a recess at an inner side of the second midsole layer and having a through hole in a forefoot region of the second midsole layer. The first midsole layer may nest in the recess of the second midsole layer and extend over the through hole of the second midsole layer. The first midsole layer may have a first hardness and the second midsole layer may have a second hardness greater than the first hardness. In such a configuration, the first midsole layer may be referred to as a core that is relatively soft and the second midsole layer may also be referred to as a shell that supports the softer shell.

In an example, the first midsole layer may extend through the through hole of the second midsole layer, and an outer surface of the first midsole layer may include a longitudinal groove extending rearward from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole. In other words, the relatively soft first midsole layer defines a longitudinal groove like that described above to provide flexibility and grip of the medial and lateral portions of the first midsole layer separated by the longitudinal groove.

In another aspect, a heel region of the article of footwear may further promote ease of travel when worn during hiking downhill, for example. More specifically, a surface tangent to an outer surface of the midsole in a heel region of the midsole may arc continuously upward and rearward to an upper edge of the midsole in a direction from a midfoot region of the midsole to a heel region of the midsole at a longitudinal cross-section of the sole structure. Stated differently, because the surface arcs continuously upward and rearward, it does not jut rearward and then ascend forward at the rear of the heel region as many other articles of footwear do that provide a heel region of a midsole that extend further rearward of the footwear upper. Instead, by more closely tracking the profile of a wearer's heel, the sole structure can more easily clear a descending terrain when a wearer steps forward without necessitating that the wearer lift his or her foot further above the terrain.

In another aspect advantageous for flexibility and downhill strides, the article of footwear may include a heel counter disposed at a heel region of the article of footwear. The heel counter may be bifurcated by a split in the heel counter that extends downward along a rear of the heel counter from an upper edge of the heel counter partway toward a bottom extent of the heel counter. Accordingly, such a split is expected to align with a wearer's Achilles tendon. As the heel counter may be a relatively stiff component in comparison to the footwear upper, the split will promote its flexibility. As the wearer's heel is more elevated relative to the forefoot during a downhill foot placement and toe-off than on level terrain, the ability of the heel counter to flex at the split may further enable proper foot position on a downhill slope.

In an example of an article of footwear disclosed herein, the article of footwear has a sole structure that includes a midsole having an inner surface with an elongated transverse recess in a forefoot region of the midsole. The midsole defines a drain passage extending through the midsole from an entrance opening of the drain passage at the elongated transverse recess and to an exit opening of the drain passage at an outer surface of the midsole.

In an example of an article of footwear disclosed herein, the article of footwear has a sole structure that includes a midsole having a longitudinal groove in an outer surface of the midsole. The longitudinal groove extends from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole. The outer surface of the midsole includes a convex medial portion disposed at a medial side of the longitudinal groove and extending substantially from the longitudinal groove to a medial side wall of the midsole and from an anterior portion of the forefoot region to the midfoot region, and includes a convex lateral portion disposed at a lateral side of the longitudinal groove and extending substantially from the longitudinal groove to a lateral side wall of the midsole and from the anterior portion of the forefoot region to the midfoot region.

The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the modes for carrying out the present teachings when taken in connection with the accompanying drawings. It should be understood that even though embodiments may be separately described in the following Figures, single features thereof may be combined in additional embodiments.

Referring to the drawings, wherein like reference numbers refer to like components throughout the views, FIGS. 1-4 show an embodiment of an article of footwear 10 that includes a sole structure 12 and a footwear upper 14 (also referred to herein as an upper). The article of footwear 10 herein is depicted as a leisure shoe or an athletic shoe. Most specifically, the article of footwear 10 is configured for hiking, with features providing particular benefits for hiking through hilly and wet terrain. However, the present teachings are not limited to such footwear categories, and also encompass dress shoes, work shoes, sandals, slippers, boots, or any other category of footwear.

The article of footwear 10 has three general regions: a forefoot region 16, a midfoot region 18, and a heel region 20, which are also the forefoot region, the midfoot region, and the heel region, respectively, of the sole structure 12 and the footwear upper 14 and the components thereof. The footwear 10 also includes a medial side 22 (best shown in FIG. 1) and a lateral side 24 (best shown in FIG. 2) opposite from the medial side 22.

The forefoot region 16 includes portions of the article of footwear 10 generally corresponding with the toes and the joints connecting the metatarsals with the phalanges of a wearer's foot. The midfoot region 18 includes portions of the article of footwear 10 generally corresponding with the arch area of the foot, and the heel region 20 generally corresponds with rear portions of the foot, including the calcaneus bone. The medial side 22 and the lateral side 24 extend through each of forefoot region 16, the midfoot region 18, and the heel region 20 and correspond with opposite sides of the article of footwear 10. The forefoot region 16, the midfoot region 18, the heel region 20, the medial side 22, and the lateral side 24 are not intended to demarcate precise areas of footwear 10 but are instead intended to represent general areas of footwear 10 to aid in the following discussion.

The footwear upper 14 is secured to the sole structure 12 to define a foot-receiving cavity 36 over the sole structure 12 and has an ankle opening 38 that permits a foot to access the foot-receiving cavity 36. As such, the foot is supported on the sole structure 12 and within the footwear upper 14.

The sole structure 12 includes a midsole 26 and an outsole 28 secured to an outer surface 30 of the midsole 26 (also referred to as a ground-facing surface or a bottom surface (see FIG. 15)). In FIGS. 1 and 2, the article of footwear 10 is shown with the outsole 28 resting on a ground surface G with the footwear upper 14 above the sole structure 12.

The outer surface 30 includes the entire outer surface of the midsole 26 furthest from the foot-receiving cavity, as opposed to an inner surface 68 of the midsole 26 shown in FIG. 5 that is closer to the foot-receiving cavity 36 than the outer surface 30. The outer surface 30 may also be referred to as a ground-facing surface or a distal surface and the inner surface 68 may also be referred to as a foot-facing surface or a proximal surface. The outer surface 30 includes a bottom portion 30A as well as a medial side wall portion 30B (also referred to as a medial side-facing surface) and a lateral side wall portion 30C (also referred to as a lateral side-facing surface). The outer surface 30 is best shown in FIG. 15 and the outsole 28 secured thereto is best illustrated in FIG. 14. Moreover, the outsole 28 extends upwards onto and is secured to the footwear upper 14 at a rear of the heel region 20 and at an anterior portion 16A of the forefoot region 16. The portion of the outsole 28 that extends onto the footwear upper 14 at the anterior portion 16A of the forefoot region 16 may be referred to as a toe shield portion 28A.

An outer surface 40 of the outsole 28 may also be referred to as a ground-facing surface or a distal surface and includes the entire exposed surface of the outsole 28. In other words, the outer surface 40 includes the side-facing surfaces and the front-facing and rear-facing surfaces at the outer side (exposed side) of the outsole 28 as well. The outer surface 40 is further from the foot-receiving cavity 36 than is an inner surface 42 of the outsole 29, which is also referred to as a foot-facing surface or proximal and is best shown in FIG. 19.

The outsole 28 includes an underfoot portion 28C (also referred to as a bottom portion or ground-facing portion), a medial side wall 28B (also referred to as a medial side wall portion), a lateral side wall 28D (also referred to as a lateral side wall portion), the toe shield portion 28A, and a rear portion 28G.

The outer surface 30 of the midsole 26 includes the bottom portion 30A at a bottom portion 26A of the midsole 26, the medial side wall portion 30B at a medial side wall portion 26B of the midsole 26, and the lateral side wall portion 30C at a lateral side wall portion 26C of the midsole 26. The inner surface 42 of the outsole 28 is best shown in FIGS. 16-19 and is secured to the outer surface 30 of the midsole 26, which is best shown in FIGS. 15-18.

FIGS. 1-3 show some features of the midsole 26 that are discussed in greater detail herein, such as exit openings 50A and 50B of drain passages at the medial and lateral sides 22, 24 of the midsole 26, respectively. Medial and lateral drain passages 52A and 52B that include the exit openings 50A, 50B are shown and discussed with respect to FIG. 9 in greater detail. The midsole includes a medial flex groove 54A and a lateral flex groove 54B in the outer surface 30 at the bottom portion 30A0 that extend transversely inward from the medial side wall portion 30B and from the lateral side wall portion 30C of the outer surface 30 of the midsole 26, respectively. The midsole 26 also includes a longitudinal groove 60 in the outer surface 30 of the midsole 26, as shown in FIGS. 3 and 15.

FIGS. 1-3 also show some features of the outsole 28 that are discussed in greater detail herein, such as a medial notch 62A in the medial side wall 28B of the outsole 28. The medial notch 62A extends into the underfoot portion 28C of the outsole and underlies the medial flex groove 54A of the midsole 26. As shown in FIG. 2, the outsole 28 also has a lateral notch 62B in a lateral side wall 28D of the outsole 28. The lateral notch 62B extends into the underfoot portion 28C of the outsole 28 and underlies the lateral flex groove 54B of the midsole 26. In this manner, the notches 62A, 62B of the outsole 28 enhance the flexibility of the sole structure 12 at the flex grooves 54A, 54B of the midsole 26. Additionally, the notches 62A, 62B of the outsole 28 are in alignment with the exit openings 50A, 50B of the drain passage(s). Stated differently, the exit openings 50A, 50B are exposed at the side wall portions 26B, 26C due to the notches 62A, 62B.

FIG. 3 shows a portion of a longitudinal split 64 of the outsole 28 which is also shown and discussed further with respect to FIGS. 14 and 19. The longitudinal split 64 underlies the longitudinal groove 60 of the midsole 26 and extends through the midfoot region 18 and forefoot region 16 of the outsole 28 and continues through the toe shield portion 28A to bifurcate the outsole 28. Due to the longitudinal split 64, the outsole 28 can thus partially cover and protect a toe portion 14A of the footwear upper 14 without adversely affecting flexibility of the midsole 26 along the longitudinal groove 60.

FIG. 4 is a rear view of the article of footwear 10 and shows a heel counter 66 in hidden lines within the footwear upper 14 at the heel region 20 of the article of footwear 10. The heel counter 66 is also shown and discussed with respect to FIG. 20 and is bifurcated.

FIG. 5 is a plan view of the midsole 26 showing the inner surface 68. The midsole 26 is referred to as a full-length midsole as it extends through the forefoot, midfoot, and heel regions 16, 18, and 20, and provides a footbed at the inner surface 68 in the forefoot, midfoot, and heel regions 16, 18, and 20.

The inner surface 68 includes a recess 70 that extends in the forefoot and midfoot regions 16, 18 and may extend partway into the heel region 20. The recess 70 has a depth and shape that matches a thickness and shape of a plate 72 shown in FIG. 6. Specifically, a lip 78 of the midsole 26 bounding the recess 70 has the same shape and dimensions as the outer perimeter 79 of the plate 72 such the plate 72 may nest in the recess 70 with the outer perimeter 79 at the lip 78. Additionally, a protrusion 74, 76 of the midsole 26 extends upwards from the recess 70 and has a longitudinal leg 74 and a transverse leg 76 that intersects the longitudinal leg 74. The recess 70 and the protrusion 74, 76 are locating features for positioning the plate 72 on the inner surface 68 as discussed with respect to FIG. 7. Stated differently, the recess 70 and the protrusion 74, 76 are configured as locating features adapted to receive the plate 72, e.g., for positioning the plate 72 on the midsole 26. In an example, the midsole 26 may include either or both of the recess 70 or the protrusion 74, 76.

The midsole 26 also defines elongated transverse recesses 80A, 80B. Specifically, the midsole 26 includes an elongated medial transverse recess 80A and an elongated lateral transverse recess 80B. The transverse recesses 80A, 80B extend into the midsole 26 deeper than the recess 70 and extend from opposite ends of the transverse protrusion 76 beyond the recess 70 (e.g., further transversely outward than the recess 70) to an inner medial side wall 82A and to an inner lateral side wall 82B of the midsole 26, respectively. The midsole 26 also defines entrance openings 84A, 84B of the respective medial and lateral drain passages 52A, 52B. The entrance openings 84A, 84B are near the ends of the transverse recesses 80A, 80B closest to the inner side walls 82A, 82B, respectively. In this manner, the entrance openings 84A, 84B are at a relatively low spot of the foot-facing surface 68. The midsole 26 including the protrusion 74, 76, recesses 80A, 80B, inner medial and lateral side walls 82A, 82B is a monolithic, unitary component (one-piece).

An axis 86 extending along a center of a length of the transverse recesses 80A, 80B is skewed relative to the longitudinal leg 74 so that the end of the medial recess 80A at the entrance opening 84A is further forward than the end of the lateral transverse recess 80B at the entrance opening 84B. Stated differently, the axis 86 angles rearward from the medial side 22 to the lateral side 24. The axis 86 is positioned at an expected location of a bending axis of the metatarsal phalangeal joints of a wearer during dorsiflexion and represents the bending axis, the wearer having a foot size corresponding with the article of footwear 10. For example, the axis 86 may be positioned at a location correlating with the location of the bending axis based on a population average of wearers of the size of the article of footwear 10. As such, the midsole 26 will resiliently flex at the area of the drain passages 52A, 52B, and may alternate between partially or completely closing and then opening the entrance openings 84A, 84B as the sole structure 12 undergoes repeated dorsiflexion. This may help to actively pump fluid through the drain passages 52A, 52B and out of the exit openings 50A, 50B, helping to clear fluid that may pool at the midsole foot-facing surface 68 due to wet conditions.

FIG. 6 is a plan view of the plate 72 included in the sole structure 12. As shown in FIG. 8, the plate 72 extends in the forefoot region 16, and may also extend in the midfoot region 18 and even slightly into the heel region 20. The plate 72 is relatively rigid in comparison to the midsole 26 and the outsole 28. In this manner, the plate 72 affords protection to a wearer's foot in the forefoot region 16 and midfoot region 18, such as by shielding rough terrain, including rocks.

The plate 72 defines a longitudinal slot 88 extending through the plate 72 and a transverse slot 90 intersecting with the longitudinal slot 88 and also extending through the plate 72. Stated differently, both of the slots 88, 90 extend entirely through the plate from a foot-facing surface 72A of the plate 72 to a ground-facing surface 72B of the plate 72. The foot-facing surface 72A may also be referred to as an inner surface or as a proximal surface. The ground-facing surface 72B may also be referred to as an outer surface or as a distal surface. The longitudinal slot 88 and the transverse slot 90 both terminate inward of the outer perimeter 79 of the plate 72 and together define four quadrants of the plate 72: a forward medial quadrant FM, a forward lateral quadrant FL, a rear medial quadrant RM, and a rear lateral quadrant RL. As can be seen, the quadrants FM. FL, RM, and RL are not of the same size and, furthermore, because the ends of both of the longitudinal slot 88 and the transverse slot 90 are inward of the outer perimeter 79, adjacent quadrants are connected with one another near the outer perimeter 79.

The longitudinal and transverse slots 88, 90 enable the plate 72 to flex in multiple ways, helping to ensure stable footing on rough terrain. For example, the four quadrants FM, FL, RM, and RL of the plate 72 are shaped and dimensioned to flex relative to one another at the slots 88, 90 both under dorsiflexion of the sole structure 12 and under torsional forces on the sole structure 12. For example, a medial end 90A of the transverse slot 90 is forward of a lateral end 90B of the transverse slot 90. The medial end 90A may also be referred to herein as a medial terminus. The lateral end 90B may also be referred to herein as a lateral terminus 90B. The transverse slot 90 is generally linear and elongated in the transverse direction, angling rearward from the medial side 22 to the lateral side 24. Like the transverse recesses 80A, 80B of the midsole 26, the transverse slot 90 is positioned to underlie an expected location of the metatarsal phalangeal joints of the wearer and, more specifically, a bending axis of the foot at the metatarsal phalangeal joints. As such, the transverse slot 90 enables the plate 72 to flex under dorsiflexion with the wearer's foot along the same axis 86 as the midsole 26, for reasons discussed below, with the foot-facing surface 72A of the plate 72 in compression and the ground-facing surface 72B of the plate 72 in extension.

As is evident in FIGS. 6 and 7, the transverse slot 90 is wider at both its medial terminus 90A and its lateral terminus 90B than at a middle segment 90C. In other examples, it may be wider only at one of the medial terminus 90A or the lateral terminus 90B. The increased width of the transverse slot 90 at its terminus 90A and/or 90B helps to reduce stress concentrations in the plate 72 at the portions of the plate 72 outward of the slot 90 along the bending axis 86 and further increase flexibility. As shown, the transverse slot 90 has the middle segment 90C that intersects with the longitudinal slot 88, a medial segment 90AA that includes the medial terminus 90A, and a lateral segment 90BB that includes the lateral terminus 90B. The middle segment 90C is between the medial terminus 90A and the lateral terminus 90B, and, more specifically, is between and connects the medial segment 90AA and the lateral segment 90BB. As shown, both of the medial segment 90AA (including the medial terminus 90A) and the lateral segment 90BB (including the lateral terminus 90B) have a greater fore-aft width W1 than a fore-aft width W2 of the middle segment 90C.

As shown in FIGS. 7 and 8, the locating features of the midsole 26 (e.g., the protrusions 74, 76 and the lip 78) are cooperatively configured to receive the plate 72. More particularly, the protrusion 74 extends through and aligns with the longitudinal slot 88, the protrusion 76 extends through and aligns with the middle segment 90C, and the elongated medial and lateral transverse recesses 80A, 80B underlie the transverse slot 90 at the medial and lateral segments 90AA, 90BB, respectively. The plate 72 nests in the recess 70 of the midsole 26 with the protrusions 74, 76 extending through the slots 88, 90 and the lip 78 closely tracking and surrounding the outer perimeter 80, and with the foot-facing surface 72A of the plate 72 flush with the inner surface 68 of the midsole 26 surrounding the plate 72, as best shown in FIGS. 17 and 18, for example. Such an implementation best allows the plate 72 to be correctly located and positioned relative to the midsole 26 during assembly to achieve both the flexibility and foot protection goals.

As indicated in FIG. 8, the longitudinal groove 60 of the midsole 26 underlies and is aligned with the longitudinal slot 88 of the plate 72. A rear end 60A of the groove 60 directly underlies a rear end 88A of the longitudinal slot 88. In this manner, the longitudinal groove 60 of the midsole 26 and the longitudinal slot 88 of the plate 72 are cooperatively configured to enhance flexibility of the sole structure 12. Most specifically, the longitudinal slot 88 may allow the plate 72 to flex in torsion where the sole structure 12 is twisted along its length (such as the forefoot region 16 moving clockwise relative to the midfoot region 18 or the heel region 20, or vice versa). Additionally, a lateral portion of the midsole 26 (lateral portion 26BB shown in FIG. 9 as a portion between the groove 60 and the lateral side wall portion 26C) may more easily flex relative to a medial portion of the midsole 26 (medial portion 26AA shown in FIG. 9 as a portion between the groove and the medial side wall portion 26B) in the forefoot region 16 due to the groove 60, such as by flexing toward or away from one another at the ground-facing surface 30 along the groove 60 when walking on uneven terrain. Likewise, the longitudinal slot 88 enables the plate 72 to more easily flex, such as with the outer surface 72B of the plate 72 in compression and the forward medial quadrant FM moving toward the forward lateral quadrant FL and the rear medial quadrant RM moving toward the rear lateral quadrant FR.

The materials of the footwear upper 14, the midsole 26, the outsole 28, the heel counter 66, and the plate 72 are selected to ensure these components function as intended and provide the advantages described herein. In a non-limiting example, the footwear upper 14 may be one or more components or layers and may be a braided construction, a knitted (e.g., warp-knitted) construction or a woven construction. As shown, the upper 14 has a unitary, sock-like construction and may extend underfoot between the medial side 22 and the lateral side 24, or may be secured to a strobel, for example. An insole (not shown) may overlie the plate 72 and the midsole 26 in the foot-receiving cavity 36.

In the example shown, the foam of the midsole 26 may include a foamed polymeric material and may be at least partially a polyurethane (PU) foam, a polyurethane ethylene-vinyl acetate (EVA) foam, and may include heat-expanded and molded EVA foam pellets. The foamed polymeric material may include one or more polymers. The one or more polymers may include an elastomer, including a thermoplastic elastomer (TPE). The one or more polymers may include aliphatic polymers, aromatic polymers, or mixture of both. In one example, the one or more polymers may include homopolymers, copolymers (including terpolymers), or mixtures of both. The copolymers may be random copolymers, block copolymers, alternating copolymers, periodic copolymers, or graft copolymers, for instance. The one or more polymers may include olefinic homopolymers or copolymers or a mixture of olefinic homopolymers and copolymers. Examples of olefinic polymers include polyethylene (PE) and polypropylene (PP). For example, the PE may be a PE homopolymer such as a low density PE or a high density PE, a low molecular weight PE or an ultra-high molecular weight PE, a linear PE or a branched chain PE, etc. The PE may be an ethylene copolymer such as, for example, an ethylene-vinyl acetate (EVA) copolymer, an ethylene-vinyl alcohol (EVOH) copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-unsaturated mono-fatty acid copolymer, etc. The one or more polymers may include a polyacrylate such as a polyacrylic acid, an ester of a polyacrylic acid, a polyacrylonitrile, a polyacrylic acetate, a polymethyl acrylate, a polyethyl acrylate, a polybutyl acrylate, a polymethyl methacrylate, a polyvinyl acetate, etc., including derivatives thereof, copolymers thereof, and any mixture thereof, in one example. The one or more polymers may include an ionomeric polymer. The ionomeric polymer may be a polycarboxylic acid or a derivative of a polycarboxylic acid, for instance. The ionomeric polymer may be a sodium salt, a magnesium salt, a potassium salt, or a salt of another metallic ion. The ionomeric polymer may be a fatty acid modified ionomeric polymer. Examples of ionomeric polymers include polystyrene sulfonate, and ethylene-methacrylic acid copolymers. The one or more polymers may include a polycarbonate. The one or more polymers may include a fluoropolymer. The one or more polymers may include a polysiloxane. The one or more polymers may include a vinyl polymer such as polyvinyl chloride (PVC), polyvinyl acetate, polyvinyl alcohol, etc. The one or more polymers may include a polystyrene. The polystyrene may be a styrene copolymer such as, for example, an acrylonitrile butadiene styrene (ABS), a styrene acrylonitrile (SAN), a styrene ethylene butylene styrene (SEBS), a styrene ethylene propylene styrene (SEPS), a styrene butadiene styrene (SBS), etc. The one or more polymers may include a polyamide (PA). The PA may be a PA 6, PA 66, PA 11, or a copolymer thereof. The polyester may be an aliphatic polyester homopolymer or copolymer such as polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyrate, and the like. The polyester may be a semi-aromatic copolymer such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT). The one or more polymers may include a polyether such as a polyethylene glycol or polypropylene glycol, including copolymers thereof. The one or more polymers may include a polyurethane, including an aromatic polyurethane derived from an aromatic isocyanate such as diphenylmethane diisocyanate (MDI) or toluene diisocyanate (TDI), or an aliphatic polyurethane derived from an aliphatic isocyanate such as hexamethylene diisocyanate (HDI) or isophone diisocyanate (IPDI), or a mixture of both an aromatic polyurethane and an aliphatic polyurethane.

The foamed polymeric material of the midsole 26 may be a chemically foamed polymeric material, which is foamed using a chemical blowing agent that forms a gas when heated. For example, the chemical blowing agent can be an azo compound such as adodicarbonamide, sodium bicarbonate, or an isocyanate. Alternatively, or additionally, the foamed polymeric material of the midsole 26 may be a physically foamed polymeric material, which is foamed using a physical blowing agent which changes phase from a liquid or a supercritical fluid to a gas due to changes in temperature and/or pressure.

Optionally, in addition to the one or more polymers, the polymeric material of the midsole 26 may further include one or more fillers such as glass fiber, powdered glass, modified or natural silica, calcium carbonate, mica, paper, wood chips, modified or natural clays, modified or unmodified synthetic clays, talc, etc. Similarly, the polymeric material optionally may further include one or more colorants, such as pigments or dyes. Other optional components of the polymeric material include processing aids, ultra-violet light absorbers, and the like.

The foamed polymeric material of the midsole 26 may be a crosslinked foamed polymeric material, i.e., a foamed material in which covalent crosslinking bonds exist between at least a portion of the one or more polymers. A crosslinked foamed polymeric material can be formed by including a crosslinking agent in the polymeric material used to form the foam. The crosslinking agent can be a peroxide-based crosslinking agent such as dicumyl peroxide. Alternatively, the foamed polymeric material can be an uncrosslinked foamed polymeric material which has thermoplastic properties. The foamed polymeric material may be an elastomeric foamed material.

In an example, the outsole 28 may be formed from materials that may generally include natural or synthetic rubber or other suitably durable materials. The material or materials for the outsole 28 may be selected to provide a desirable combination of durability, flexibility, and at least the predetermined coefficient of friction discussed herein. Synthetic rubbers that may be used include polybutadiene rubber, ethylene propylene rubber (EPR), styrene isoprene styrene (SIS) copolymer rubber, and styrene butadiene rubber.

In the example shown, the plate 72 may be relatively more rigid than the midsole 26 and may stiffen the footbed in the forefoot region 16 and the midfoot region 18, protecting the foot from rocks and other forces that may contact the outsole 28 during wear. The plate 72 may be but is not limited to a thermoplastic polyurethane. In an example, the plate 72 may be a polyether block amide PEBAX®, available from Arkema, Inc. in King of Prussia, Pennsylvania USA. The plate 72 may have a greater compressive stiffness and/or a greater bending stiffness than each of the midsole 26 and the outsole 28 and may be thinner than each of the midsole 26 and the outsole 28. The heel counter 66 may also be relatively more stiff than the material of the footwear upper 14 and may be but is not limited to the materials described above that may be used for the plate 72.

FIG. 8 is a plan view of the sole structure 12 included in the article of footwear 10 of FIG. 1 including the plate 72 and midsole 26 of FIG. 7 and showing the outsole 28. The recesses 80A and 80B of the midsole 26 align with the medial segment 90AA and the lateral segment 90BB, respectively, and the medial and lateral notches 62A, 62B of the outsole 28 align with the exit openings 50A, 50B, respectively. The longitudinal split 64 of the outsole 28 aligns with the longitudinal groove 60 of the midsole 26.

FIG. 9 shows the drain passages 52A, 52B extending through the midsole 26 with the entrance openings 84A, 84B at the elongated transverse recesses 80A, 80B, respectively. The exit openings 50A, 50B are at the respective medial and lateral side wall portions 30B, 30C of the outer surface 30 of the midsole 26. As previously discussed, by placing the entrance openings 84A, 84B at the transverse recesses 80A, 80B of the midsole 26 and in alignment with the axis 86, dorsiflexion of the midsole 26 may help to move water through the drain passages 52A, 52B and out of the exit openings 50A, 50B. The exit openings 50A, 50B are lower than the respective entrance openings 84A, 84B, and the drain passages 52A, 52B angle downward and outward from the entrance openings 84A, 84B to the respective exit openings 50A, 50B. This will help to continuously drain water out by gravity. Additionally, as the sole structure 12 is dorsiflexed and the midsole 26 resiliently deforms, a forward extent of the opening 84A may move closer to a rear extent of the opening 84A so as to temporarily close the opening 84A until after toe-off as the foot moves through a forward stride. The exit opening 50B may also temporarily close in the same manner. The exit openings 50A, 50B may repeatedly open and close in the same manner with repeated dorsiflexion. This opening and closing during wear may act to continuously pump water filling the drain passages 52A, 52B out of the drain passages 52A, 52B during wear. The exit openings 50A, 50B are smaller than the entrance openings 84A, 84B to minimize water entrance through the exit openings 50A, 50B.

FIG. 10 shows an alternative midsole 26D usable in place of midsole 26 in the article of footwear 10 and alike in all aspects to midsole 26 except with an alternative arrangement of drain passages 152A, 152B. Specifically, the exit openings 50A, 50B are moved lower on the midsole 26D, from the medial side wall portion 30B and the lateral side wall portion 30C to the bottom portion 30A of the outer surface 30. Like the drain passages 52A, 52B, the drain passages 152A, 152B are aligned with the elongated transverse recesses 80A, 80B and will continuously drain by gravity as well as possibly continuously open and close with repeated dorsiflexion to create a pumping action that moves water through the drain passages 152A, 152B.

FIGS. 9 and 10 illustrate that both the midsole 26 and the alternative midsole 26D have the medial portion 26AA and the lateral portion 26BB that generally fall on opposite sides of the longitudinal groove 60. The ground-facing surface 30 at the bottom portion 30A has a convex medial portion 30A1 and a convex lateral portion 30A2 each of which have a separate convex profile at a transverse cross-section of the midsole 26 or 26D as shown. Such a configuration enables separate contact, grip, and conformity of the convex medial and lateral portions 30A1, 30A2 with an uneven ground surface, similar to a cloven hoof.

FIG. 15 best shows that the convex medial portion 30A1 is disposed at a medial side of the longitudinal groove 60 and extends substantially from the longitudinal groove 60 to the medial side wall portion 26B and from the anterior portion 16A of the forefoot region 16 to the midfoot region 18. Similarly, the convex lateral portion 30A2 is disposed at a lateral side of the longitudinal groove 60 and extends substantially from the longitudinal groove 60 to the lateral side wall portion 26C and from the anterior portion 16A of the forefoot region 16 to the midfoot region 18. Accordingly, the convex medial portion 30A1 and the convex lateral portion 30A2 are both convex at the bottom portion 30A in both the transverse direction and the longitudinal direction.

FIG. 11 is a plan view of the midsole 26 with an alternative plate 172 for the sole structure 12 that may be used in the article of footwear 10. FIG. 12 is a plan view of the plate 172 of FIG. 11. Specifically, the plate 172 is configured like plate 72 in all aspects except that the transverse slot 190 that intersects with the longitudinal slot 88 does not have medial and lateral end segments that are wider in the fore-aft direction. In fact, a medial terminus 190A and a lateral terminus 190B of the transverse slot 190 are much further inward from the outer perimeter 179 of the plate 172 than the termini 90A, 90B.

FIG. 13 is a perspective view of another alternative plate 272 for the sole structure 12 that may be used in the article of footwear 10. The plate 272 is like plate 172 in all aspects except having a transverse slot 290 that is longer than the transverse slot 190 such that it includes a medial terminus 290A and a lateral terminus 290B closer to the outer perimeter 80. Like plate 172, the transverse slot 290 does not have medial and lateral end segments that are wider in the fore-aft direction.

FIG. 14 is a bottom view of the sole structure 12 included in the article of footwear 10 of FIG. 1. The outsole 28 is secured to the outer surface 30 of the midsole 26. The medial notch 62A extends from the medial side wall 28B of the outsole 28 into the underfoot portion 28C of the outsole 28 and underlies the medial flex groove 54A of the midsole 26. Similarly, the lateral notch 62B extends from the lateral side wall 28D of the outsole 28 into the underfoot portion 28C of the outsole 28 and underlies the lateral flex groove 54B of the midsole 26. The notches 62A, 62B are in alignment with the exit openings 50A, 50B of the drain passages 52A, 52B to expose the exit openings 50A, 50B on the midsole 26 at the exterior of the sole structure 12.

FIG. 14 also illustrates the bifurcated forefoot portion 28E of the outsole 28 due to the longitudinal split 64 that underlies the longitudinal groove 60 of the midsole 26 and shows the midsole 26 exposed at the longitudinal split 64. The bifurcated forefoot portion 28E includes a medial forefoot portion 28E1 and a lateral forefoot portion 28E2 separate by the split 64. A portion of the midfoot region 18 of the outsole 28 is also bifurcated by the split 64.

The outsole 28 tracks the convex medial and lateral portions 30A1, 30A2 of the outer surface 30 of the midsole 26. Stated differently, the medial forefoot portion 28E1 and the lateral forefoot portion 28E2 at the outer surface 40 of the outsole 28 are both convex at the underfoot portion 28C in both the transverse direction and the longitudinal direction and have separate convex profiles as best shown in FIG. 16. In the heel region 20, the outsole 28 does not have separate convex profiles in a transverse direction at medial and lateral portions, as best shown in FIG. 17, just as the midsole 26 does not have separate convex profiles in a transverse direction at medial and lateral portions in the heel region 20. Flexibility for adapting the outer surface 40 of the outsole 28 to uneven terrain is thus focused in the forefoot region 16.

FIGS. 14-19 best show that the outsole 28 includes a plurality of spaced tread elements 28F at the outer surface 40 of the outsole 28, only some of which are indicated with reference numbers. The tread elements 28F are disposed from the medial side 22 to the lateral side 24 of the sole structure 12 in each of the forefoot region 16, the midfoot region 18, and the heel region 20 including on the toe shield portion 28A. The tread elements 28F define a portion of a ground engaging surface of the sole structure 12. The tread elements 28F ensure sufficient contact with the ground surface G even in the case of an uneven ground surface. Additionally, the tread elements 28F have sufficient compliance to increase friction relative to the ground surface G in comparison to a ground engaging surface without the tread elements 28F.

FIG. 15 is a bottom view of the midsole included in the sole structure of the article of footwear of FIG. 1. The medial and lateral flex grooves 54A, 54B fall along the axis 86 as do the medial and lateral elongated transverse recesses 80A, 80B and, in this manner, the medial and lateral flex grooves 54A, 54B underlie and are in alignment with the elongated transverse recesses 80A, 80B, respectively. The medial and lateral flex grooves 54A, 54B are also in alignment with the exit openings 50A. 50B of the drain passages 52A, 52B, which also fall along the axis 86 and so increase flexibility to further enhance the pumping action of the dorsiflexing midsole 26 to empty the drain passages 52A, 52B.

FIG. 18 a surface tangent to the outer surface 30 of the midsole 26 in the heel region 20 is represented in profile as surface S and arcs continuously upward and rearward to an upper edge 26G of the midsole 26 in a direction from the midfoot region 18 to the heel region 20 at a longitudinal cross-section of the sole structure 12. Stated differently, because the surface S arcs continuously upward and rearward, it does not jut rearward and then ascend forward at the rear of the heel region 20 as many other articles of footwear do that provide a heel region of a midsole that extends far rearward of the footwear upper. Instead, by providing a midsole 26 that more closely tracks the profile of a wearer's heel, the sole structure 12 can more easily clear a descending terrain when a wearer steps forward. That is, the wearer need not lift his or her foot as far above the terrain to avoid inadvertently hitting the terrain during a forward stride.

FIG. 19 shows that the inner surface 42 of the outsole 28 has separate concavities at medial and lateral portions separated by the split 64. More specifically, the inner surface 42 includes a medial concavity 42A and a lateral concavity 42B that are separated by the split 64 and are shaped and dimensioned to secure to and follow the shape of the convex profiles of the medial and lateral portions 30A1, 30A2 of the midsole 26.

FIG. 20 is a rear view of the heel counter 66 included in the article of footwear 10 of FIG. 1. The heel counter 66 is bifurcated by a split 66A that extends downward along a rear 92 of the heel counter 66 from an upper edge 94 of the heel counter partway toward a bottom extent 96 of the heel counter 66. Accordingly, such a split 66A is expected to align with a wearer's Achilles tendon. As the heel counter 66 may be a relatively stiff component in comparison to the footwear upper 14, the split will promote flexibility of the heel counter 66. As the heel is more elevated relative to the forefoot during downhill foot placement and toe-off when going downhill than when on level terrain, the ability of the heel counter 66 to flex at the split 66A may further enable proper foot position on a downhill slope.

FIG. 21 is a first midsole layer 126A of an alternative midsole 126 shown in FIGS. 23-27 to be used in place of the midsole 26 in the sole structure 12 of the article of footwear 10 of FIG. 1. FIG. 22 is a second midsole layer 126B of the midsole 126. The midsole 126 thus includes multiple layers. The first midsole layer 126A has a different hardness than the second midsole layer 126B. For example, the midsole layers may each comprise foam, and the foam of the second midsole layer 126B may be more dense than the foam of the first midsole layer 126A. Similarly, the midsole layers 126A, 126B may have different hardnesses. The first midsole layer 126A may have a first hardness and the second midsole layer 126B may have a second hardness greater than the first hardness. Such hardnesses and densities may be measured according to standard ASTM testing, for example.

As best shown in FIGS. 21 and 27, the first midsole layer 126A has an inner surface 168 that includes locating features 170, 174, 176 for the plate 272 shown in FIGS. 13 and 17. The inner surface 168 includes a recess 170 that extends in the forefoot and midfoot regions 16, 18 and may extend partway into the heel region 20 and has a depth and shape that matches a thickness and shape of the plate 272. Specifically, a lip 178 of the first midsole layer 126A bounds the recess 170 and has the same shape and dimensions as the outer perimeter 179 of the plate 272. Additionally, a protrusion 174, 176 of the first midsole layer 126A extending upwards from the recess 170 has a longitudinal leg 174 and a transverse leg 176 that intersects the longitudinal leg 174. The recess 170 and the protrusion 174, 176 are configured as locating features adapted to receive the plate 272, e.g., for positioning the plate 272 on the inner surface 168, similarly as discussed with respect to the plate 72 of FIG. 7. In an example, the first midsole layer 126A may include either or both of the recess 170 or the protrusion 174, 176

As shown in FIG. 22, the second midsole layer 126B has an inner surface 168A with a recess 126C and a through hole 129 in a forefoot region 16 of the second midsole layer 126B. The through hole 129 extends rearward into the midfoot region 18. The first midsole layer 126A is shaped and dimensioned to nest in the recess 126C of the second midsole layer 126B and to extend over the through hole 129 as well as through the through hole 129, as shown in FIGS. 23-26. FIG. 25, for example, shows the first midsole layer 126A overlaying the second midsole layer 126B in the heel region 20 and extending through the through hole 129. The relatively-soft first midsole layer 126A is a full-length (having a forefoot region 16, a midfoot region 18, and a heel region 20) and provides a full-length footbed at the inner surface 168. As such, the first midsole layer 126A may be referred to as a core that is relatively soft and the second midsole layer 126B may be referred to as a shell that is relatively hard in comparison to and supports the softer shell.

FIG. 23 is a bottom view of the midsole layers 126A, 126B of FIGS. 21 and 22 assembled together as the midsole 126. The first midsole layer 126A is shown extending through the through hole 129 of the second midsole layer, as further illustrated in FIG. 24. FIG. 23 shows a longitudinal groove 160 in an outer surface 130 of the first midsole layer 126A. The longitudinal groove 160 extends rearward from a forward extent of the forefoot region 16 to the midfoot region 18. The first midsole layer 126A defines a medial portion 126AA and a lateral portion 126BB that generally fall on opposite sides of the longitudinal groove 160. The outer surface 130 has a convex medial portion 130A1 and a convex lateral portion 130A2 each of which have a separate convex profile as indicated in FIG. 26, and also at a transverse cross-section of the midsole 126. Such a configuration enables separate contact and grip of the convex medial and lateral portions 130A1, 130A2 with an uneven ground surface, similar to a cloven hoof. In other words, the relatively soft first midsole layer 126A defines a longitudinal groove 160 similar to longitudinal groove 60 of the midsole 26 described above to provide flexibility and separate contact and grip of medial and lateral portions 126AA, 126BB of the first midsole layer 126A that are separated by the longitudinal groove 160.

FIG. 27 is an exploded view of the alternative sole structure 112 including the midsole 126, the plate 272, and an outsole 28 as described with respect to the sole structure 12. The sole structure 112 is configured for a left foot whereas the midsole 126 of FIGS. 21-26 is configured for a right foot. The midsole 126 for the left foot and the plate 272 for the left foot are mirror images of those shown in FIGS. 23-26. Although no drain passages are shown in the midsole 126, drain passages 152A, 152B may be included to align with the notches 62A, 62B of the outsole 28.

Accordingly, the article of footwear 10 and sole structure 12, 112 disclosed herein provide features such as the plate 72, 172, or 272 that enable protection of the foot while hiking over rough terrain while still enabling flexibility of the forefoot region 16 to conform to uneven terrain, as provided by the longitudinal groove 60 or 160 of the midsole 26 or 126 and the separate convex profiles of the medial and lateral portions 26AA, 26BB or 126AA, 126BB. The surface profile in the heel region 20 as well as the heel counter 66 also help to provide steady footing on downhill slopes, for example. Additionally, features to help drain water, such as drain passages 52A, 52B or 152A, 152B may also be included.

The following Clauses provide example configurations of an article of footwear disclosed herein.

• • Clause 1. An article of footwear comprising: a sole structure including a plate extending in a forefoot region of the sole structure; and wherein the plate defines a longitudinal slot extending through the plate and a transverse slot intersecting with the longitudinal slot and extending through the plate, the longitudinal slot and the transverse slot both terminating inward of an outer perimeter of the plate and together defining four quadrants of the plate.
  • Clause 2. The article of footwear of Clause 1, wherein the four quadrants of the plate are shaped and dimensioned to flex relative to one another both under dorsiflexion of the sole structure and under torsional forces on the sole structure.
  • Clause 3. The article of footwear of any of Clauses 1-2, wherein a medial end of the transverse slot is forward of a lateral end of the transverse slot.
  • Clause 4. The article of footwear of any of Clauses 1-2, wherein: the transverse slot has a middle segment that intersects with the longitudinal slot and has a lateral terminus and a medial terminus with the middle segment between the lateral terminus and the medial terminus; and either or both of the lateral terminus and the lateral terminus has a greater fore-aft width than the middle segment.
  • Clause 5. The article of footwear of any of Clauses 1-2, wherein the sole structure includes a midsole having an inner surface with at least one of a recess or a protrusion configured as a locating feature adapted to receive the plate.
  • Clause 6. The article of footwear of Clause 5, wherein: the midsole includes an elongated transverse recess in the inner surface; and the elongated transverse recess underlies the transverse slot.
  • Clause 7. The article of footwear of Clause 6, wherein the elongated transverse recess is a medial transverse recess that underlies a medial end segment of the transverse slot, and the midsole further includes an elongated lateral transverse recess that underlies a lateral end segment of the transverse slot.
  • Clause 8. The article of footwear of Clause 6, wherein the midsole defines a drain passage extending through the midsole from an entrance opening of the drain passage at the elongated transverse recess to an exit opening of the drain passage at an outer surface of the midsole.
  • Clause 9. The article of footwear of Clause 5, wherein the midsole includes a medial flex groove and a lateral flex groove in an outer surface of the midsole that extend transversely inward at a bottom portion of the outer surface from a medial side wall portion of the outer surface and a lateral side wall portion of the outer surface of the midsole, respectively.
  • Clause 10. The article of footwear of Clause 9, wherein the sole structure includes an outsole secured to the outer surface of the midsole, and the outsole having: a medial side wall, a lateral side wall, and an underfoot portion extending from the medial side wall to the lateral side wall; a medial notch in the medial side wall of the outsole, the medial notch extending into the underfoot portion of the outsole and underlying the medial flex groove of the midsole; and/or a lateral notch in the lateral side wall of the outsole, the lateral notch extending into the underfoot portion of the outsole and underlying the lateral flex groove of the midsole.
  • Clause 11. The article of footwear of Clause 5, wherein the midsole includes a longitudinal groove in an outer surface of the midsole, the longitudinal groove extending from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole.
  • Clause 12. The article of footwear of Clause 11, wherein the longitudinal groove of the midsole underlies and is aligned with the longitudinal slot of the plate.
  • Clause 13. The article of footwear of Clause 11, wherein the outer surface of the midsole includes: a convex medial portion disposed at a medial side of the longitudinal groove and extending substantially from the longitudinal groove to a medial side wall of the midsole and from an anterior portion of the forefoot region of the midsole to the midfoot region of the midsole; and a convex lateral portion disposed at a lateral side of the longitudinal groove and extending substantially from the longitudinal groove to a lateral side wall of the midsole and from the anterior portion of the forefoot region of the midsole to the midfoot region of the midsole.
  • Clause 14. The article of footwear of Clause 13, wherein the convex medial portion and the convex lateral portion of the outer surface of the midsole each have a separate convex profile at a transverse cross-section of the midsole.
  • Clause 15. The article of footwear of Clause 11, wherein the sole structure includes an outsole secured to the outer surface of the midsole; and wherein the outsole has a bifurcated forefoot portion defining a longitudinal split that underlies the longitudinal groove of the midsole such that the midsole is exposed at the longitudinal split of the outsole.
  • Clause 16. The article of footwear of Clause 15, further comprising: a footwear upper secured to the sole structure and defining a foot-receiving cavity over the sole structure; and wherein the outsole includes a toe shield portion that wraps upward onto a toe portion of the footwear upper and the longitudinal split of the outsole continues through the toe shield portion.
  • Clause 17. The article of footwear of Clause 5, wherein the midsole includes: a first midsole layer that includes the at least one of a recess or a protrusion; and a second midsole layer having a recess at an inner side of the second midsole layer and having a through hole in a forefoot region of the second midsole layer; wherein the first midsole layer nests in the recess of the second midsole layer and extends over the through hole of the second midsole layer; and wherein the first midsole layer has a first hardness and the second midsole layer has a second hardness greater than the first hardness.
  • Clause 18. The article of footwear of Clause 17, wherein the first midsole layer extends through the through hole of the second midsole layer, and an outer surface of the first midsole layer includes a longitudinal groove extending rearward from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole.
  • Clause 19. The article of footwear of any of Clauses 1-2, wherein: the sole structure includes a midsole that supports the plate; and a surface tangent to an outer surface of the midsole in a heel region of the midsole arcs continuously upward and rearward to an upper edge of the midsole in a direction from a midfoot region of the midsole to the heel region of the midsole at a longitudinal cross-section of the sole structure.
  • Clause 20. The article of footwear of any of Clauses 1-2, further comprising: a heel counter disposed at a heel region of the article of footwear; and wherein the heel counter is bifurcated by a split in the heel counter that extends downward along a rear of the heel counter from an upper edge of the heel counter partway toward a bottom extent of the heel counter.
  • Clause 21. An article of footwear comprising: a sole structure including a midsole having an inner surface with an elongated transverse recess in a forefoot region of the midsole; and wherein the midsole defines a drain passage extending through the midsole from an entrance opening of the drain passage at the elongated transverse recess and to an exit opening of the drain passage at an outer surface of the midsole.
  • Clause 22. The article of footwear of Clause 21, wherein: the elongated transverse recess is a medial elongated transverse recess extending along the inner surface at a medial portion of the midsole; the inner surface of the midsole has a lateral elongated transverse recess extending along the inner surface of the midsole at a lateral portion of the midsole; and a medial end of the medial elongated transverse recess is forward of a lateral end of the lateral elongated transverse recess.
  • Clause 23. The article of footwear of any of Clauses 21-22, wherein the midsole includes a medial flex groove and a lateral flex groove in the outer surface of the midsole that extend transversely inward at a bottom portion of the outer surface from a medial side wall portion of the outer surface of the midsole and a lateral side wall portion of the outer surface of the midsole, respectively.
  • Clause 24. The article of footwear of Clause 23, wherein the sole structure includes an outsole secured to the outer surface of the midsole, and the outsole having: a medial side wall, a lateral side wall, and an underfoot portion extending from the medial side wall to the lateral side wall; a medial notch in the medial side wall of the outsole, the medial notch extending into the underfoot portion of the outsole and underlying the medial flex groove of the midsole; and/or a lateral notch in the lateral side wall of the outsole, the lateral notch extending into the underfoot portion of the outsole and underlying the lateral flex groove of the midsole.
  • Clause 25. The article of footwear of any of Clauses 21-22, wherein a surface tangent to an outer surface of the midsole in a heel region of the midsole arcs continuously upward and rearward to an upper edge of the midsole in a direction from a midfoot region of the midsole to the heel region of the midsole at a longitudinal cross-section of the sole structure.
  • Clause 26. The article of footwear of any of Clauses 21-22, further comprising: a heel counter disposed at a heel region of the article of footwear; and wherein the heel counter is bifurcated by a split in the heel counter that extends downward along a rear of the heel counter from an upper edge of the heel counter partway toward a bottom extent of the heel counter.
  • Clause 27. An article of footwear comprising: a sole structure including a midsole having a longitudinal groove in an outer surface of the midsole, the longitudinal groove extending from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole; wherein the outer surface of the midsole includes a convex medial portion disposed at a medial side of the longitudinal groove and extending substantially from the longitudinal groove to a medial side wall of the midsole and from an anterior portion of the forefoot region of the midsole to the midfoot region of the midsole; and a convex lateral portion disposed at a lateral side of the longitudinal groove and extending substantially from the longitudinal groove to a lateral side wall of the midsole and from the anterior portion of the forefoot region of the midsole to the midfoot region of the midsole.
  • Clause 28. The article of footwear of Clause 27, wherein the convex medial portion and the convex lateral portion each have a separate convex profile at a transverse cross-section of the midsole.
  • Clause 29. The article of footwear of any of Clauses 27-28, wherein: the sole structure includes an outsole secured to the outer surface of the midsole; and the outsole has a bifurcated forefoot portion defining a longitudinal split that underlies the longitudinal groove of the midsole.
  • Clause 30. The article of footwear of Clause 29, wherein the midsole is exposed at the longitudinal split of the outsole.
  • Clause 31. The article of footwear of Clause 29, further comprising: a footwear upper secured to the sole structure and defining a foot-receiving cavity over the sole structure; and wherein the outsole includes a toe shield portion that wraps upward onto a toe portion of the footwear upper.
  • Clause 32. The article of footwear of Clause 31, wherein the longitudinal split of the outsole continues through the toe shield portion.
  • Clause 33. The article of footwear of any of Clauses 27-28, wherein: the midsole includes: a first midsole layer that includes the longitudinal groove; and a second midsole layer having an inner surface with a recess and having a through hole in the forefoot region of the midsole; the first midsole layer nests in the recess of the second midsole layer and extends over the through hole; and the first midsole layer has a first hardness and the second midsole layer has a second hardness greater than the first hardness.
  • Clause 34. The article of footwear of Clause 33, wherein the first midsole layer overlies the second midsole layer in a heel region of the article of footwear and extends through the through hole in the second midsole layer.

An “article of footwear”, a “footwear article of manufacture”, and “footwear” may be considered to be both a machine and a manufacture. Assembled, ready to wear footwear articles (e.g., shoes, sandals, boots, etc.), as well as discrete components of footwear articles (such as a midsole, an outsole, an upper component, etc.) prior to final assembly into ready to wear footwear articles, are considered and alternatively referred to herein in either the singular or plural as “article(s) of footwear”.

“A”, “an”, “the”, “at least one”, and “one or more” are used interchangeably to indicate that at least one of the items is present. A plurality of such items may be present unless the context clearly indicates otherwise. All numerical values of parameters (e.g., of quantities or conditions) in this specification, unless otherwise indicated expressly or clearly in view of the context, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. In addition, a disclosure of a range is to be understood as specifically disclosing all values and further divided ranges within the range.

The terms “comprising”, “including”, and “having” are inclusive and therefore specify the presence of stated features, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, or components. Orders of steps, processes, and operations may be altered when possible, and additional or alternative steps may be employed. As used in this specification, the term “or” includes any one and all combinations of the associated listed items. The term “any of” is understood to include any possible combination of referenced items, including “any one of” the referenced items. The term “any of” is understood to include any possible combination of referenced claims of the appended claims, including “any one of” the referenced claims.

For consistency and convenience, directional adjectives may be employed throughout this detailed description corresponding to the illustrated embodiments. Those having ordinary skill in the art will recognize that terms such as “above”, “below”, “upward”, “downward”, “top”, “bottom”, etc., may be used descriptively relative to the figures, without representing limitations on the scope of the invention, as defined by the claims.

The term “longitudinal” particularly refers to a direction extending a length of a component. For example, a longitudinal direction of a shoe extends between a forefoot region and a heel region of the shoe. The term “forward” or “anterior” is used to particularly refer to the general direction from a heel region toward a forefoot region, and the term “rearward” or “posterior” is used to particularly refer to the opposite direction, i.e., the direction from the forefoot region toward the heel region. In some cases, a component may be identified with a longitudinal axis as well as a forward and rearward longitudinal direction along that axis. The longitudinal direction or axis may also be referred to as an anterior-posterior direction or axis.

The term “transverse” particularly refers to a direction extending a width of a component. For example, a transverse direction of a shoe extends between a lateral side and a medial side of the shoe. The transverse direction or axis may also be referred to as a lateral direction or axis or a mediolateral direction or axis.

The term “vertical” particularly refers to a direction generally perpendicular to both the lateral and longitudinal directions. For example, in cases where an outsole is planted flat on a ground surface, the vertical direction may extend from the ground surface upward. It will be understood that each of these directional adjectives may be applied to individual components of a sole. The term “upward” or “upwards” particularly refers to the vertical direction pointing towards a top of the component, which may include an instep, a fastening region and/or a throat of an upper. The term “downward” or “downwards” particularly refers to the vertical direction pointing opposite the upwards direction, toward the bottom of a component and may generally point towards the bottom of a sole structure of an article of footwear.

The “interior” of an article of footwear, such as a shoe, particularly refers to portions at the space that is occupied by a wearer's foot when the shoe is worn. The “inner side” of a component particularly refers to the side or surface of the component that is (or will be) oriented toward the interior of the component or article of footwear in an assembled article of footwear. The “outer side” or “exterior” of a component particularly refers to the side or surface of the component that is (or will be) oriented away from the interior of the shoe in an assembled shoe. In some cases, other components may be between the inner side of a component and the interior in the assembled article of footwear. Similarly, other components may be between an outer side of a component and the space external to the assembled article of footwear. Further, the terms “inward” and “inwardly” particularly refer to the direction toward the interior of the component or article of footwear, such as a shoe, and the terms “outward” and “outwardly” particularly refer to the direction toward the exterior of the component or article of footwear, such as the shoe. In addition, the term “proximal” particularly refers to a direction that is nearer a center of a footwear component, or is closer toward a foot when the foot is inserted in the article of footwear as it is worn by a user. Likewise, the term “distal” particularly refers to a relative position that is further away from a center of the footwear component or is further from a foot when the foot is inserted in the article of footwear as it is worn by a user. Thus, the terms proximal and distal may be understood to provide generally opposing terms to describe relative spatial positions.

While various embodiments have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the embodiments. Any feature of any embodiment may be used in combination with or substituted for any other feature or element in any other embodiment unless specifically restricted. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

While several modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and exemplary of the entire range of alternative embodiments that an ordinarily skilled artisan would recognize as implied by, structurally and/or functionally equivalent to, or otherwise rendered obvious based upon the included content, and not as limited solely to those explicitly depicted and/or described embodiments.

Claims

1. An article of footwear comprising:

a sole structure including a plate extending in a forefoot region of the sole structure; and

wherein the plate defines a longitudinal slot extending through the plate and a transverse slot intersecting with the longitudinal slot and extending through the plate, the longitudinal slot and the transverse slot both terminating inward of an outer perimeter of the plate and together defining four quadrants of the plate.

2. The article of footwear of claim 1, wherein the four quadrants of the plate are shaped and dimensioned to flex relative to one another both under dorsiflexion of the sole structure and under torsional forces on the sole structure.

3. The article of footwear of claim 1, wherein a medial end of the transverse slot is forward of a lateral end of the transverse slot.

4. The article of footwear of claim 1, wherein:

the transverse slot has a middle segment that intersects with the longitudinal slot and has a lateral terminus and a medial terminus with the middle segment between the lateral terminus and the medial terminus; and

either or both of the lateral terminus and the lateral terminus has a greater fore-aft width than the middle segment.

5. The article of footwear of claim 1, wherein the sole structure includes a midsole having an inner surface with at least one of a recess or a protrusion configured as a locating feature adapted to receive the plate.

6. The article of footwear of claim 5, wherein:

the midsole includes an elongated transverse recess in the inner surface; and

the elongated transverse recess underlies the transverse slot.

7. The article of footwear of claim 6, wherein the elongated transverse recess is a medial transverse recess that underlies a medial end segment of the transverse slot, and the midsole further includes an elongated lateral transverse recess that underlies a lateral end segment of the transverse slot.

8. The article of footwear of claim 6, wherein the midsole defines a drain passage extending through the midsole from an entrance opening of the drain passage at the elongated transverse recess to an exit opening of the drain passage at an outer surface of the midsole.

9. The article of footwear of claim 5, wherein the midsole includes a medial flex groove and a lateral flex groove in an outer surface of the midsole that extend transversely inward at a bottom portion of the outer surface from a medial side wall portion of the outer surface and a lateral side wall portion of the outer surface of the midsole, respectively.

10. The article of footwear of claim 9, wherein the sole structure includes an outsole secured to the outer surface of the midsole, and the outsole having:

a medial side wall, a lateral side wall, and an underfoot portion extending from the medial side wall to the lateral side wall;

a medial notch in the medial side wall of the outsole, the medial notch extending into the underfoot portion of the outsole and underlying the medial flex groove of the midsole; and/or

a lateral notch in the lateral side wall of the outsole, the lateral notch extending into the underfoot portion of the outsole and underlying the lateral flex groove of the midsole.

11. The article of footwear of claim 5, wherein the midsole includes a longitudinal groove in an outer surface of the midsole, the longitudinal groove extending from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole.

12. The article of footwear of claim 11, wherein the longitudinal groove of the midsole underlies and is aligned with the longitudinal slot of the plate.

13. The article of footwear of claim 11, wherein the outer surface of the midsole includes:

a convex medial portion disposed at a medial side of the longitudinal groove and extending substantially from the longitudinal groove to a medial side wall of the midsole and from an anterior portion of the forefoot region of the midsole to the midfoot region of the midsole; and

a convex lateral portion disposed at a lateral side of the longitudinal groove and extending substantially from the longitudinal groove to a lateral side wall of

the midsole and from the anterior portion of the forefoot region of the midsole to the midfoot region of the midsole.

14. The article of footwear of claim 13, wherein the convex medial portion and the convex lateral portion of the outer surface of the midsole each have a separate convex profile at a transverse cross-section of the midsole.

15. The article of footwear of claim 11, wherein the sole structure includes an outsole secured to the outer surface of the midsole; and

wherein the outsole has a bifurcated forefoot portion defining a longitudinal split that underlies the longitudinal groove of the midsole such that the midsole is exposed at the longitudinal split of the outsole.

16. The article of footwear of claim 15, further comprising:

a footwear upper secured to the sole structure and defining a foot-receiving cavity over the sole structure; and

wherein the outsole includes a toe shield portion that wraps upward onto a toe portion of the footwear upper and the longitudinal split of the outsole continues through the toe shield portion.

17. The article of footwear of claim 5, wherein the midsole includes:

a first midsole layer that includes the at least one of a recess or a protrusion; and

a second midsole layer having a recess at an inner side of the second midsole layer and having a through hole in a forefoot region of the second midsole layer;

wherein the first midsole layer nests in the recess of the second midsole layer and extends over the through hole of the second midsole layer; and

wherein the first midsole layer has a first hardness and the second midsole layer has a second hardness greater than the first hardness.

18. The article of footwear of claim 17, wherein the first midsole layer extends through the through hole of the second midsole layer, and an outer surface of the first midsole layer includes a longitudinal groove extending rearward from a forward extent of a forefoot region of the midsole to a midfoot region of the midsole.

19. The article of footwear of claim 1, wherein:

the sole structure includes a midsole that supports the plate; and

a surface tangent to an outer surface of the midsole in a heel region of the midsole arcs continuously upward and rearward to an upper edge of the midsole in a direction from a midfoot region of the midsole to the heel region of the midsole at a longitudinal cross-section of the sole structure.

20. The article of footwear of claim 1, further comprising:

a heel counter disposed at a heel region of the article of footwear; and

wherein the heel counter is bifurcated by a split in the heel counter that extends downward along a rear of the heel counter from an upper edge of the heel counter partway toward a bottom extent of the heel counter.