CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority from US Provisional Patent Application No. 63/086,716, filed 02 October 2020.

TECHNICAL FIELD

[0001] The present disclosure relates to an article of footwear and more particularly to a sole structure for an article of footwear.

BACKGROUND

[0002] Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper provides a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure is secured to a lower surface of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces and absorbing energy (i.e., imparting cushioning), the sole structure may provide traction and control potentially harmful foot motion, such as over pronation. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a wide variety of ambulatory activities, such as walking and running.

[0003] The sole structure generally incorporates multiple layers that are conventionally referred to as an insole, a midsole, and an outsole. The insole is a thin, cushioning member located within the upper and adjacent the plantar (lower) surface of the foot to enhance footwear comfort. The midsole, which is traditionally attached to the upper along the entire length of the upper, forms the middle layer of the sole structure and serves a variety of purposes that include controlling foot motions and providing cushioning. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear-resistant material that includes texturing to improve traction. [0004] The primary element of a conventional midsole is a resilient, polymer foam material, such as polyurethane or ethylvinylacetate, that extends throughout the length of the footwear. The properties of the polymer foam material in the midsole are primarily dependent upon factors that include the dimensional configuration of the midsole and the specific characteristics of the material selected for the polymer foam, including the density of the polymer foam material. By varying these factors throughout the midsole, the relative stiffness, degree of ground reaction force attenuation, and energy absorption properties may be altered to meet the specific demands of the activity for which the footwear is intended to be used.

SUMMARY

[0005] A sole structure for an article of footwear includes a midsole formed of a foamed polymer, a ground contacting outsole surface, and a cushioning system disposed between the midsole and the ground contacting outsole surface. The cushioning system includes a polymeric plate defining an upper plate and a lower plate provided in a spaced relationship. The upper plate and lower plate are integrally connected at a posterior portion of the sole structure. At least two vertically stacked fluid-filled chambers are provided between the upper plate and the lower plate within the midfoot region of the cushioning system. The at least two vertically stacked fluid- filled chambers include a first midfoot fluid-filled chamber coupled to the upper plate, and a second midfoot fluid-filled chamber coupled to and between the first midfoot fluid-filled chamber and the lower plate.

[0006] The cushioning system further includes at least two laterally arranged fluid-filled chambers provided between the upper plate and the lower plate within the midfoot region of the cushioning system. The at least two laterally arranged fluid- filled chambers include a lateral forefoot fluid-filled chamber and a medial forefoot fluid-filled chamber. The lateral forefoot fluid-filled chamber is positioned between a lateral edge of the sole structure and the medial forefoot fluid-filled chamber, and the medial forefoot fluid-filled chamber is positioned between a medial edge of the sole structure and the lateral forefoot fluid-filled chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a side view of a lateral side of an article of footwear. [0008] FIG. 2 is a side view of a medial side of an article of footwear.

[0009] FIG. 3 is a side perspective view of the medial heel region of an article of footwear.

[0010] FIG. 4 is a schematic partial cross-sectional view of stacked, fluid- filled chambers with internal tensile elements.

[0011] FIG. 5 is a bottom view of a sole structure for an article of footwear.

[0012] FIG. 6 is a top perspective view of the forefoot region of an article of footwear.

[0013] FIG 7A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0014] FIG 7B is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0015] FIG 7C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0016] FIG 7D is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0017] FIG 7E is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0018] FIG 7F is a schematic side view of an embodiment of an article of footwear having a cushioning structure with an intermediate bump stop in a heel region.

[0019] FIG 8 A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a fluid-filled chamber in a heel region. [0020] FIG 8B is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a fluid-filled chamber in a heel region. [0021] FIG 8C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a fluid-filled chamber in a heel region. [0022] FIG 8D is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a fluid-filled chamber in a heel region. [0023] FIG 9A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a mechanical cushioning element in a heel region.

[0024] FIG 9B is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a mechanical cushioning element in a heel region.

[0025] FIG 9C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a mechanical cushioning element in a heel region.

[0026] FIG 9D is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a mechanical cushioning element in a heel region.

[0027] FIG 10A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0028] FIG 10B is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0029] FIG 10C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0030] FIG 10D is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0031] FIG 10E is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0032] FIG 1 OF is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region. [0033] FIG 10G is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element in a heel region.

[0034] FIG 11 A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam element in a heel region.

[0035] FIG 1 IB is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam element in a heel region.

[0036] FIG 11C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam element in a heel region.

[0037] FIG 1 ID is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam element in a heel region.

[0038] FIG 12A is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element and a mechanical cushioning element in a heel region.

[0039] FIG 12B is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element and a mechanical cushioning element in a heel region.

[0040] FIG 12C is a schematic side view of an embodiment of an article of footwear having a cushioning structure with a foam cushioning element and a mechanical cushioning element in a heel region.

[0041] FIG. 13 is a top side view of an article of foorwear including a dual tie down closure system.

[0042] FIG. 14 is a top lateral perspective view of the throat of an article of footwear.

DETAILED DESCRIPTION

[0043] The following discussion and accompanying figures disclose an article of footwear 10 (also referred to as the article 10) in accordance with the present disclosure. In general, the present article 10 incorporates a novel cushioning system where the upper substantially rests on a cantilevered plate that is supported, in part, via one or more cushioning features provided on an underside of the cantilevered plate (i.e., between the cantilevered plate and a connected ground plate). The article 10 is depicted in the figures and discussed below as having a configuration that is suitable for athletic activities, particularly running. The concepts disclosed with respect to the article 10 may, however, be applied to footwear styles that are specifically designed for a wide range of other athletic activities, including basketball, baseball, football, soccer, walking, and hiking, for example, and may also be applied to various non-athletic footwear styles. Accordingly, one skilled in the relevant art will recognize that the concepts disclosed herein may be applied to a wide range of footwear styles and are not limited to the specific embodiments discussed below and depicted in the figures.

[0044] With reference to FIGS. 1 and 2, an article of footwear 10 is depicted that includes an upper 12 and a sole structure 14 attached to the upper 12. The article of footwear 10 may be divided into one or more regions. The regions may include a forefoot region 16, a midfoot region 18, and a heel region 20. The forefoot region 16 may correspond with toes and joints connecting metatarsal bones with phalanx bones of a foot. The midfoot region 18 may correspond with an arch area of the foot while the heel region 18 may correspond with rear portions of the foot, including a calcaneus bone. The article of footwear 10 may additionally include a medial side 22 (shown in FIG. 2) and a lateral side 24 (shown in FIG. 1) that correspond with opposite sides of the article of footwear 10 and extend through the regions 16, 18, 20. [0045] The upper 12 includes interior surfaces that defines an interior void 26 that receives and secures a foot for support on the sole structure 14. An ankle opening 28 in the heel region 20 may provide access to the interior void 26. For example, the ankle opening 28 may receive a foot to secure the foot within the void 26 and facilitate entry and removal of the foot from and to the interior void 26.

[0046] In some examples, one or more fasteners or other closure systems 30 extend across the upper 12 to adjust a fit of the interior void 26 around the foot while concurrently accommodating entry and removal of the foot therefrom. The fasteners or other closure systems 30 may include laces, straps, cords, latching mechanisms, clasps, snaps, hook-and-loop, or any other suitable type of fastener.

[0047] The upper 12 may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void 26. Suitable materials of the upper 12 may include, textiles, foam, leather, and synthetic leather. The materials may be selected and located to impart properties of durability, air- permeability, wear-resistance, flexibility, and comfort to the foot while disposed within the interior void 26

[0048] The sole structure 14 is attached to an underside of the upper 12 and provides the article of footwear 10 with support and cushioning during use. Namely, the sole structure 14 attenuates ground reaction forces caused by the article of footwear 10 striking the ground during use. Accordingly, and as set forth below, the sole structure 14 may incorporate one or more materials having energy absorbing characteristics to allow the sole structure 14 to minimize the impact experienced by a user when wearing the article of footwear 10.

[0049] The sole structure 14 may include a midsole 36, an outsole 38, and one or more cushioning systems 40 disposed generally between the midsole 36 and the outsole 38. During use, the cushioning system 40 may work in concert with the midsole 36 to attenuate ground reaction forces while providing a stable and responsive platform to support the wearer’s foot. The cushioning system 40 may include a plate 42 that extends generally between an anterior end 44 of the article of footwear 10 and a posterior end 46 of the article of footwear 10. The cushioning system 40 may further include one or more fluid-filled chambers 48 that are operative to compress under the weight of the wearer.

[0050] With continued reference to FIGS. 1-2, the midsole 36 is shown as extending approximately from the anterior end 44 of the article of footwear 10 to the posterior end 46 or the article of footwear 10. As further shown, in some embodiments, the midsole 36 may extend beyond the anterior and posterior extremes of the upper 12. The midsole 36 is secured to a lower portion of upper 12 and is positioned to extend under the foot during use. Among other purposes, midsole 36 attenuates ground reaction forces and absorbs energy (i.e., imparts cushioning) when walking or running, for example. The midsole 36 may be formed from an energy absorbing material such as, for example, polymer foam. Forming the midsole 36 from an energy-absorbing material, such as, for example, an ethylvinylacetate foam allows the midsole 36 to attenuate ground-reaction forces caused by movement of the article of footwear 10 over ground during use.

[0051] An outsole 38 or outsole surface is provided on a lower, ground-facing surface of the cushioning system 40, and on an opposite side of the cushioning system 40 from the midsole 36 and upper 12. The outsole 38 may define a ground-engaging surface 50 that is operative to provide wear-resistance and to enhance traction between the article of footwear 12 and the ground. The outsole 38 may be formed from a resilient material such as, for example, a rubber or a softer thermoplastic polyurethane, which can improve traction and durability. The ground-engaging surface 50 may include one or more traction elements that extend outward to provide the article of footwear 10 with increased traction during use.

[0052] As best shown in FIG. 3, the midsole 36 may serve to attach the cushioning system 40 to the upper 12. In one embodiment, the cushioning system 40 may be coupled to the midsole 36, for example, by adhering a portion of the plate 42 to a lower surface of the midsole 36 (i.e., via a suitable adhesive - not shown). Alternatively, the cushioning sy stem 40 may be attached to the midsole 36 by molding a material of the midsole 36 directly to the plate 42 (e.g., insert injection molding). For example, the plate 42 may be disposed within a cavity of a mold (not shown) used to form the midsole 36. When the midsole 36 is formed (i.e. by foaming a polymer material), the material of the midsole 36 is joined to the material of the plate 42, thereby forming a unitary structure having both the midsole 36 and the plate 42.

[0053] While the cushioning system 40 is described and shown as being attached to an underside of the midsole 36 (i.e., on an opposite side of the midsole from the upper 12), a portion of the cushioning system 40 could alternatively be embedded within the material of the midsole 36. For example, a portion of the plate 42 may be encapsulated by the midsole 36 such that a portion of the midsole 36 extends through or to opposing sides of a portion of the plate 42. Further yet, the plate 42 could be disposed within the midsole 36 but not be fully encapsulated. For example, the plate 42 could be visible around a perimeter of the midsole 36 while a portion of the midsole 36 extends between the plate 42 and the upper 12 and another portion of the midsole 36 extends between the plate 42 and the outsole 38.

[0054] As illustrated, the plate 42 may include an upper cantilevered plate 60 that is integrally coupled with a lower ground plate 62 (i.e., at a joint/joint region 64) to form a spring-like shock absorber. In a general sense, the upper plate 60 and lower plate 62 are configured to deflect toward each other in response to a static or dynamic load applied by the wearer. In some configurations, the joint region 64 may include a radiused bend that smoothly couples the spaced upper and lower plates 60, 62. The cushioning system 40 may further include one or more fluid-filled chambers 48 provided between the upper plate 60 and the lower plate 62 to aid in controlling the deflection magnitude (and/or rate of deflection) between the plates 60, 62 apart from the joint 64.

[0055] In one configuration, the upper and lower plates 60, 62 may each extend along a longitudinal dimension of the sole structure 14, and in some embodiments one or both may fully extend from the anterior end 44 of the sole structure 14 to the posterior end 46 of the sole structure 14. In some configurations, the upper plate 60 may extend along at least a portion of the heel region 20 and midfoot region 18. In others, the upper plate 60 may extend across at least a portion of the heel region 20, midfoot region 18, and forefoot region 16. Additionally, in some configurations, the lower plate 62 may extend across at least a portion of the heel region 20, midfoot region 18, and forefoot region 16 [0056] In one embodiment, the plate 42 may comprise a single sheet of a relatively rigid material that is folded/ wrapped back on itself. For example, the plate 42 may be formed from a non-foamed polymer material or, alternatively, from a composite material containing fibers such as carbon fibers. Suitable materials may include thermoplastic polyurethane (TPU), polyamides (e.g., PA6 or PA66), or other engineering polymers. The material may include a fiber fill, such as short or long fiber glass, aramid, bamboo, or carbon fibers, or may include similar continuous fabrics. Forming the plate 42 from a relatively rigid material allows the plate 42 to distribute forces associated with use of the article 10 while maintaining the upper plate 60 and lower plate 62 in a spaced relationship. In some embodiments, this spaced relationship is desirably greater than about 5 mm, or greater than about 8 mm, or even greater than about 10 mm. In other embodiments, instead of being thermoformed from a single sheet, the plate 62 may also be injection molded into a substantially final shape.

[0057] In one configuration, the joint region 64 of the plate 42 may be provided within, or posterior to the heel region 20 of the sole structure 14, and may be formed with a suitable thickness and stiffness to withstand expected static and impact loads without permitting the upper and lower plates 60, 62 to overly deflect and/or come into contact with each other. In such an embodiment, an intermediate recess/void 66 may exist between the upper and lower plates 60, 62 within the heel region 20. In an unloaded/relaxed state, this recess/void 66 may have a first height 68. measured normal to the ground. When worn, static and impact loads from the wearer may urge the upper and lower plates 60, 62 into a more closely spaced relationship. Said another way, the recess/void 66 may be compressed to have a second height that is less than the first height 68.

[0058] The degree to which the plates 60, 62 flex toward each other in the heel region 20 may largely be controlled by the stiffness of the plate 42 within the joint region 64. While some elastic flexure/movement of the upper and lower plates 60, 62 is desirable to provide cushioning/force attenuation, if the joint region 64 is not sufficiently stiff, the deflection could be larger than desired, which could cause the shoe to feel unstable.

[0059] In some embodiments, so that the entire heel region 20 experiences similar reaction forces from the cushioning system, the joint region 64 of the plate 42 may be provided rearward of the posterior end 70 of the upper 12 and/or rearward of a posterior end 72 of the midsole 36.

[0060] While the cushioning response within the heel region 20 may largely be attributable to the elasticity/stiffhess of the joint region 64 of the plate 42, the cushioning system 40 may rely on one or more fluid-filled chambers 48 to provide the cushioning response within the midfoot region 18 and/or within the forefoot region 16. In the embodiment shown in FIGS. 1-3, the cushioning system 40 includes a first fluid-filled chamber 80 and a second fluid-filled chamber 82 provided within the midfoot region 18, and a fluid-filled chamber 84 provided in the forefoot region 1 .

[0061] As illustrated in FIGS. 1-4, the first fluid-filled chamber 80 is disposed generally between the upper plate 60 and the second fluid-filled chamber 82 while the second fluid-filled chamber 82 is disposed between the lower plate 62 and the first fluid-filled chamber 80. Specifically, the first fluid-filled chamber 80 is attached to a lower surface of the upper plate 60 at a first side and is attached to the second fluid- filled chamber 82 at a second side. The second fluid-filled chamber 82 is attached at a first side to the upper surface of the lower plate 62 and is attached to the first fluid- filled chamber 80 at a second side. Additionally or alternatively, the first fluid-filled chamber 80 may be attached to the second fluid-filled chamber 82 by thermally bonding (e.g., melting/welding) the material of the first fluid-filled chamber 80 and the material of the second fluid-filled chamber 82 at a junction of the first fluid-filled chamber 80 and the second fluid-filled chamber 82.

[0062] Similar to the first and second fluid-filled chambers 80, 82, the forefoot fluid-filled chamber 84 may be provided between the upper plate 60 and the lower plate 62. In one embodiment, the forefoot fluid-filled chamber 84 is attached to a lower surface of the upper plate 60 at a first side and is attached to the upper surface of the lower plate 62 at a second side. The fluid-filled chambers 80, 82, 84 may be attached to one another and/or to the upper and lower plates 60, 62, respectively, via a suitable adhesive.

[0063] In one configuration, such as best shown in FIG. 5, the forefoot fluid chamber 84 may actually comprise two discrete fluid filled chambers: a medial forefoot fluid-filled chamber 86 and lateral forefoot fluid-filled chamber 88. In this embodiment, the midfoot region 18 may include two stacked fluid-filled chambers 80, 82, while the forefoot region 16 may include two laterally adjacent fluid-filled chamber 86, 88.

[0064] Referring again to FIG. 4, each of the fluid-filled chambers 80, 82, 84, 86, 88 may include a first barrier element 90 and a second barrier element 92. The first barrier element 90 and the second barrier element 92 may be formed from a sheet of thermoplastic polyurethane (TPU). Specifically, the first barrier element 90 may be formed from a sheet of TPU material and may include a substantially planar shape. The second barrier element 92 may likewise be formed from a sheet of TPU material and may be formed into the configuration shown in FIG. 4 to define an interior void 94. The first barrier element 90 may be joined to the second barrier element 92 by applying heat and pressure at a perimeter of the first barrier element 90 and the second barrier element 92 to define a peripheral seam 96. The peripheral seam 96 seals the internal interior void 94, thereby defining a volume of the respective chambers 80, 82, 84, 86, 88.

[0065] The interior void 94 of the fluid-filled chambers 80, 82, 84, 86, 88 may receive a tensile element 98 therein. Each tensile element 98 may include a series of tensile strands 100 extending between an upper tensile sheet 102 and a lower tensile sheet 104. The upper tensile sheet 102 may be attached to the first barrier element 90 while the lower tensile sheet 104 may be attached to the second barrier element 92. In this manner, when each chamber 80, 82, 84, 86, 88 receives a pressurized fluid, the tensile strands 100 of the tensile elements 98 are placed in tension. Because the upper tensile sheet 102 is attached to the first barrier element 90 and the lower tensile sheet 104 is attached to the second barrier element 92, the tensile strands 100 retain a desired shape of the respective chambers 80, 82, 84, 86, 88 when the pressurized fluid is injected into the interior void 94.

[0066] During operation, when the ground-engaging surface 50 of the outsole 38 contacts the ground, a force is transmitted via the lower plate 62 to the fluid-filled chambers 80, 82, 84, 86, 88. The applied force causes the individual fluid-filled chambers 80, 82, 84, 86, 88 to compress, thereby absorbing the forces associated with the outsole 38 contacting the ground. The force is transmitted to the upper plate 60 and midsole 36 but is not experienced by the user as a point or localized load. Instead, the forces applied through the outsole 38 are distributed across the plates 60, 62 and dampened via the cantilevered geometry of the plate 42, the dynamic response of the fluid filled chambers 48, and the compressibility of the midsole 36.

[0067] Referring to FIG 6, in one configuration the forefoot region 16 of the sole structure 14 may have a lateral width 120 that is greater than a corresponding lateral width 122 of the upper 12 measured at the same position along the longitudinal axis 124. The lateral width 120 of the sole structure 14 may be measured between the lateral edge 126 and the medial edge 128 of the sole structure 14 and orthogonal to the primary longitudinal axis 124 (best shown in FIG. 5). Similarly, the lateral width 122 of the upper 12 may be measured between the lateral edge 130 and the medial edge 132 of the upper 12 and orthogonal to the primary longitudinal axis 124.

[0068] As generally illustrated in FIG. 6, in one configuration, the medial forefoot fluid-filled chamber 86 may at least partially extend beyond the medial edge 132 of the upper 12 and lateral forefoot fluid-filled chamber 88 may at least partially extend beyond the lateral edge 130 of the upper 12 (when viewed from a top view). Doing so may provide the footwear with additional lateral stability and more even pressure distribution between the outsole 38 and the ground.

[0069] In some configurations, the lower plate 62 may include one or more up-tumed sole portions 140 that extend, for example, on a medial side of the medial forefoot fluid-filled chamber 86, on a lateral side of the lateral forefoot fluid-filled chamber 88, and on one or both of the medial side or lateral side of the second midfoot fluid-filled chamber 82. Such a configuration may provide some measure of impact protection to the fluid-filled chambers. Likewise, if the outsole 38 extends upward onto an outer surface of this up-turned sole portion 140, then the feature may further provide traction capabilities to the sidewall of the sole structure 14.

[0070] While the lower plate 62 may extend from an extreme anterior end to an extreme postenor end of the sole structure, in one configuration, the upper plate 60 may terminate immediately forward/anterior of the forefoot fluid-filled chambers 84. In this embodiment, the midsole 36 may be affixed to both an upper surface of the upper plate 60 and an upper surface of the lower plate 62.

[0071] Referring to FIGS. 5-6, in one configuration, the forefoot region 16 may include a vertical split 150 through the sole structure 14 and/or upper 12 that extends from an anterior end of the article 10. In doing so, some or all of the forefoot region 16 may be divided into a medial forefoot toe region 152, and a lateral forefoot toe region 154. When worn, the split 150 may extend between two immediately adjacent ones of the wearer’s toes. Such a design takes advantage of the independent medial and lateral fluid-filled chambers 86, 88 since the medial and lateral forefoot toe regions 152, 154 are physically separate. To provide further independence the split 150 may extend through and divide the upper 12, midsole 36, and lower plate 62. In some embodiments, the upper plate 60 may further be divided such that the split extends at least partially between the medial and lateral fluid-filled chambers 86, 88. Referring to FIG. 5, in one configuration, the split 150 in the lower plate 62 may include two segments, a forward segment 160 provided substantially along a first split axis 162, and a second, rearward segment 164 provided along a second split axis 166. In one configuration, the first split axis 162 may intersect the medial fluid-filled chamber 86, whereas the second split axis 166 may intersect the lateral fluid-filled chamber 88. Furthermore, both axes 162, 166 may be provided at angles relative to the longitudinal axis 124 of the sole 14. For example, the first split axis 162 may extend from the anterior end 44 of the sole structure 14 generally toward the medial edge 128. Conversely, the second split axis 166 may extend from the first split axis 162 toward the lateral edge 126 of the sole structure 14. Doing so may provide a further degree of independent movement between the medial and lateral sides of the forefoot, and in particular to the medial and lateral forefoot toe regions 152, 154.

[0072] Looking at the arrangement of the forefoot fluid-filled chambers 86, 88 themselves, in one configuration, the medial fluid-filled chamber 86 may be slightly forward of the lateral fluid-filled chamber 88, such that a line 168 drawn between their respective centers is provided at an oblique angle (i.e., is neither parallel nor perpendicular) relative to the longitudinal axis 124.

[0073] Referring again to FIG. 1, in one configuration, the lower plate 62 may be a generally smooth and continuous plate (when viewed from the side view), with up-tumed arcuate anterior and posterior end portions. Conversely, the upper plate 60 may include a stepped geometry that is defined by a first, forefoot portion 170, a second, midfoot portion 172, and a third heel portion 174, each being substantially parallel to the lower plate 62. The forefoot portion 170 may be the closest to the lower plate 62, the heel portion 174 may be located the farthest distance from the lower plate 62, and the midfoot portion 172 may be located an intermediate distance that is between that of the forefoot and heel portions 170, 174. Angled transition zones 176 may exist between adjacent forefoot and midfoot portions 170, 172, and between adjacent midfoot and heel portions 172, 174. Using the stepped approach may allow the cushioning system 40 to accommodate the stacked fluid-filled cushioning chambers in the midfoot region 18.

[0074] In some embodiments, the heel region 20 may further include a bumper 178 disposed between the upper and lower plates 60, 62. In one configuration, the bumper 178 may be adhered to a lower surface of the upper plate 60, and may have a height that permits a spaced relationship between the bumper 178 and the lower plate 62. In another embodiment, the bumper 178 may be a portion of the midsole 36 that extends through a hole in the upper plate 60. In still another embodiment, the bumper 178 may be a molded-in contour of the upper plate 60. The purpose of the bumper 178 may be to constrain the allowable deflection response of the heel region 20, while also preventing larger objects from becoming trapped within the cushioning system 40.

[0075] FIGS. 7A-7F schematically illustrate six alternate embodiments that each utilize a bumper 178 to constrain the force response of the cushioning system 40 as a function of vertical compression within the heel region 20. FIGS. 7A-7D provide designs that incorporate only a single bumper 178 that projects from either the upper plate 60 or the lower plate 62. In FIGS. 7E-7F, the illustrated designs include a bumper 178 that projects from both the upper plate 60 and the lower plate 62. By configuring these bumpers to eventually contact and engage with each other, the bumpers may serve to stabilize the upper in against relative motion or roll in an anterior/posterior direction or in a lateral/medial direction. For example in the embodiment show n in FIG. 7E, if a user were running, as the shoe impacted the ground, the heel would compress, through a forward/anterior surface 200 of the upper bumper and may contact a rearward/posterior surface 202 of the lower bumper to aid in stabilizing the shoe and/or prevent excessive anterior translation of the foot relative to a ground contacting lower plate 62 (e.g., during a normal running stride following the initial strike/impact, and prior to push off).

[0076] In another embodiment, instead of using a bumper, the heel region 20 may include one or more fluid-filled chambers 210 between the upper plate 60 and the lower plate 62, such as generally shown in FIGS. 8A-8D. In some embodiments, these fluid-filled chambers 210 may be air-filled bladders and may be similar in design and construction as the bladders in the midfoot. In other embodiments, such as shown in FIG. 8D, the fluid-filled chamber may be a single-height chamber that extends entirely between the upper and lower plates 60, 62.

[0077] FIGS. 9A-9D schematically illustrate alternate designs that incorporate different mechanical cushioning structures 220 between the upper plate 60 and the lower plate 62. As shown in FIGS. 9A-9C, these mechanical cushioning structures 220 may include one or more intermediate structures, such as plates, struts, and/or springs that extend between the lower plate 62 and the upper plate 60. In one configuration, each of these structures may be formed from the same plate-hke material as the upper and lower plates 60, 62, and in some embodiments they may be formed through the same manufacturing process used to form the upper and lower plates 60, 62. When the cushioning system 40 is compressed, the mechanical cushioning structure 220 may bow, articulate, or otherwise compress in a spring-like manner to elastically absorb and store energy from the impact. Upon the wearer beginning to remove the compressive load, the mechanical cushioning structure 220 may rebound and the stored energy may aid in restoring the cushioning system 40 to its original state. The embodiment shown in FIG. 9D relocates the joint region 64 entirely underneath the heel region 20 of the upper 12. In doing so, the joint region 64 takes a more vertical loading rather than the articulating moment that is experienced when it is located substantially behind/posterior to the heel region 20. [0078] Much like the embodiments show in FIGS. 9A-9D, where a mechanical shock absorbing/cushioning structure 220 is used to absorb impact loads, FIGS. 10A-10G schematically illustrate seven different embodiments where intermediate foam structures 230 are positioned between, and in contact with both the upper plate 60 and the lower plate 62. When the cushioning structure 40 experiences a vertical compression, the foam structure 230 will elastically compress as the upper plate 60 draws nearer to the lower plate 62. In one configuration, each foam structure 230 maybe substantially continuous from a macroscopic perspective and may not have any holes or apertures greater than those inherent to the foam itself. In other embodiments, the foam structure 230 may have one or more in-molded or die/laser cut apertures that may extend through a portion or the entire foam structure. In one embodiment, the foam may have at least one continuous columnar section that extends from the upper plate 60 to the lower plate 62 and is entirely devoid of apertures (i.e. , apertures larger than the cellular size of the foam itself). Such a design may provide more of a continuous force response as a function of compression. In some embodiments, less than 25% of the foam structure, 230, when viewed normal to one or both of the upper or lower plates 60, 62, may extend continuously between the upper plate and lower plate 60, 62. In another embodiment, the amount of foam that extends continuously between the upper plate and the lower plate (when viewed in two dimensions in a direction normal to one or both of the upper plate or lower plate 60, 62) may be 0%, or between 5% and 25% or between 20% and 40% or between 30% and 50%, or between 40% and 70%, or between 60% and 80%, or between 80% and 100%. Including a greater number of apertures in the foam will alter the force response such that greater initial deflection is permitted, and a greater quantity/volume of foam engages with a greater amount of deflection.

[0079] In other embodiments, such as shown in FIGS. 11 A-l ID, the cushioning system 40 may include an intermediate foam structure 230, however, instead of being designed for compression, it may instead be designed more as a hinge that primarily keeps debris out of the interior volume between the plates 60, 62, while functioning more like the bumper in FIGS. 7A-7F. In this design, the void or aperture 232 in the foam may create a cantilevered design that is closer to a living hinge than a foam cushion. In still other embodiments, such as shown in FIGS. 12A-12C, an intermediate foam structure 230 may be paired with a mechanical cushioning structure 220 to provide a composite response.

[0080] While the various intermediate cushioning configurations shown in FIGS. 7A-12C are all illustrated as being in the heel region 20, it expressly contemplated that different ones of these configurations may be used in combination, or may be located in other locations of the cushioning system 40, such as, but not limited to the midfoot region 18 and/or in the forefoot region 16. Moreover, any of these intermediate cushioning designs may be used together with, or instead of the fluid-filled chambers 48 that are illustrated in FIGS. 1-6.

[0081] In one configuration, the closure system 30 of the upper 12 may include one or more over-arch straps 180 that extend from the medial side 22 of the shoe, such as shown in FIG. 2 over the upper 12 and across to the lateral side 24, such as shown in FIG. 13. On the lateral end 182 of the strap 180, the closure system may include a dual fastening system 184. This dual fastening system 184 may include a first fastener 186 that secures and draws the strap 180 toward the forefoot region 16 of the sole structure 14. Additionally, the dual fastening system 184 may include a second fastener 188 that secures and draws the strap 180 tow ard the heel region 20 of the sole structure 14.

[0082] The closure system 30 may further include a wrap-over tongue 190, such as shown in FIG. 14, that extends from a medial side 22 of the upper 12 toward a lateral side 24 of the upper 12. When the over-arch strap 180 is drawn closed and secured, it may hold the tongue 190 in close, overlapping contact with a lateral wall 192 of the upper 12.

[0083] To manufacture the cushioning system, in one configuration, the plate 42 may begin as a die-cut or injection-molded sheet. If the base resin of the plate 42 is a thermoplastic polymer, the sheet may be heated and bent around a mold that has the contours of the upper plate 60, lower plate 62, and joint 64. Once the plate 42 is formed about this tool the up-turned sole portions 140 may then be formed via localized heating and forming. In an alternative embodiment, the plate may be injection molded into its finished form. In some embodiments, the outsole 38 may be integral to the lower plate 62, such as by being insert molded or co-molded with the plate 42. In another embodiment, the outsole 38 may be adhered to the lower plate 62, for example, via a suitable adhesive. [0084] The above features and advantages, and other features and advantages, of the present teachings are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the present teachings, as defined in the appended claims, when taken in connection with the accompanying drawings.

[0085] “A,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate that at least one of the item 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, 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; about 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, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range. Each value within a range and the endpoints of a range are hereby all disclosed as separate embodiment. The terms "comprises," "comprising," “including,” and “having,” are inclusive and therefore specify the presence of stated items, but do not preclude the presence of other items. As used in this specification, the term "or" includes any and all combinations of one or more of the listed items. When the terms first, second, third, etc. are used to differentiate various items from each other, these designations are merely for convenience and do not limit the items.

[0086] Any directional references used herein presume that the article of footwear is positioned in an upright posture on a flat, horizonal ground plane, such that the outsole is in contact with the ground plane (i.e., as if worn by a user standing in an upright manner)