US20230142549A1

Movatterモバイル変換

Info

Publication number: US20230142549A1
Application number: US17/979,261
Authority: US
Inventors: Christopher Dunning
Original assignee: Puma SE
Current assignee: Puma SE
Priority date: 2021-11-05
Filing date: 2022-11-02
Publication date: 2023-05-11
Also published as: EP4176753A1

Abstract

An article of footwear includes an upper and a sole structure coupled with the upper. The sole includes an upper plate that is configured to couple with the upper and a lower plate that is spaced from and pivotably coupled with the upper by a beam. The beam is oriented along a heel-to-toe direction of the article of footwear and is configured to provide a resistive moment to control the rotation between the upper plate and the lower plate. The sole structure further includes a midsole that is configured to surround at least a portion of the beam and to extend between the upper plate and the lower plate to provide a force that resists the rotation between the upper plate and the lower plate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional Pat. Application 63/276,182, filed on Nov. 5, 2021, the entire contents of which is hereby incorporated by reference, for any and all purposes.

REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

1. Field of the Disclosure

The present disclosure relates generally to a sole structure for an article of footwear with a flexible forefoot region to provide for improved traction. The forefoot region of the sole structure includes an upper plate that is coupled to a lower plate (i.e., an outsole) by a beam. The beam is oriented along a heel-to-toe direction (i.e., a length of the sole structure) to allow the lower plate and the upper plate to pivot in both of a lateral direction and a medial direction (e.g., about a longitudinal axis of the article of footwear). Additionally, a midsole surrounds the beam and extends between the upper and lower plates to provide a resistive force that opposes the relative rotation between the upper and lower plates. The midsole can be tuned to provide a desired amount of resistance, which may be different on each of the medial and lateral sides.

2. Description of the Background

Many conventional shoes or other articles of footwear generally comprise an upper and a sole attached to a lower end of the upper. Conventional shoes further include an internal space (i.e., a void or cavity) which is created by interior surfaces of the upper and sole that receives a foot of a user before securing the shoe to the foot. The upper generally extends upward from the sole and defines an interior cavity that completely or partially encases a foot. In most cases, the upper extends over instep and toe regions of the foot, and across medial and lateral sides thereof. Many articles of footwear may also include a tongue that extends across the instep region to bridge a gap between edges of medial and lateral sides of the upper, which define an opening into the cavity. The tongue can be disposed below a lacing or other closure system and between medial and lateral sides of the upper, to allow for adjustment of shoe tightness. The tongue may be manipulable by a user to permit entry or exit of a foot from the internal space or cavity. In addition, the lacing system may allow a user to adjust certain dimensions of the upper or the sole, thereby allowing the upper to accommodate a wide variety of foot types having varying sizes and shapes.

The upper may comprise a wide variety of materials, which may be chosen based on one or more intended uses of the shoe. The upper may also include portions comprising varying materials specific to a particular area of the upper. For example, added stability may be desirable at a front of the upper or adjacent a heel region so as to provide a higher degree of resistance or rigidity. In contrast, other portions of a shoe may include a soft woven textile to provide an area with stretch-resistance, flexibility, air-permeability, or moisture-wicking properties.

The sole is attached to a lower surface or boundary of the upper and is positioned between the upper and the ground. As a result, the sole typically provides stability and cushioning to the user when the shoe is being worn. In some instances, the sole may include multiple components, such as an outsole, a midsole, and an insole. The outsole may provide traction to a bottom surface of the sole, and the midsole may be attached to an inner surface of the outsole and may provide cushioning or added stability to the sole. For example, a sole may include a particular material or be configured in a particular shape that may increase stability at one or more desired locations along the sole, or that may reduce stress or impact energy on the foot or leg when a user is running, walking, or engaged in another activity.

Sole assemblies generally extend between a ground surface and the upper. In some examples, the sole assembly includes an outsole that provides abrasion-resistance and traction with the ground surface. The outsole may be formed from rubber or other materials that impart durability and wear-resistance, as well as enhancing traction with the ground surface.

However, while many currently available shoes have varying features related to the above-noted properties, many shoes, including athletic shoes and hiking shoes, have sole structures with bottom surfaces that are generally inflexible along a width of the sole structure (e.g., a direction extending between lateral and medial sides of the sole structure). That is, while a sole structure may offer some flexibility due to the cushioning properties of a midsole, for example, when running along a curve or over an uneven or sloped surface, a substantial portion of an outsole may remain angled to and, therefore, not in contact with the ground. As a result, the contact patch between the outsole and ground is reduced and, correspondingly, traction is also reduced. To increase traction in these types of scenarios, a user may intentionally pronate or supinate to place the outsole approximately in parallel with the ground to increase traction. Intentional pronation and supination by a user, especially when under increased loading during physical activity, can increase the possibility of injury and reduce athletic performance.

Therefore, articles of footwear having features that aid in stability and traction are desired. These and other deficiencies with the prior art are outlined in the following disclosure.

SUMMARY

A number of advantages of the articles of footwear described herein will be apparent to those having ordinary skill in the art. For example, an article of footwear can include an outsole configured as a lower plate, which can be pivotably connected with an upper plate by a beam. The lower plate and the upper plate can be spaced apart from one another by the beam and a midsole, which can surround the beam to provide a resistive force that opposes the movement (i.e., rotation) between the lower and upper plates about the beam.

According to one aspect, the present disclosure provides a sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region. The sole structure can include a first plate and a second plate. The first plate can extend from the forefoot region, through the midfoot region, to the heel region, and can be configured to couple to the upper. The second plate is disposed within the forefoot region and can be spaced from the first plate by a gap, the second plate being disposed within the forefoot region. A beam can extend between the first plate and the second plate so that the first plate is pivotally coupled to the second plate by the beam.

In some embodiments, the beam can be configured as a linear beam that is aligned along a longitudinal axis of the sole structure. The beam can define a length that is parallel to the longitudinal axis, a width that is perpendicular to the length in a lateral-to-medial direction, and a height between the first plate and the second plate that is perpendicular to both the length and the width. The length can be greater than the at least one of the width or the height. In some cases, the beam can have a rectangular cross-section taken perpendicular to the length.

In some embodiments, the sole structure can further include a midsole that can be disposed between the first plate and the second plate. The midsole can include a first midsole portion positioned along a lateral side of the beam and a second midsole portion positioned along a medial side of the beam. The first midsole portion can be a first cushioning member having a first density and can be coupled to at least one of the first plate or the second plate. The second midsole portion can be a second cushioning member having a second density that can be different from the first density, and can be coupled to at least one of the first plate or the second plate.

In some cases, the midsole can further include a third midsole portion that can be coupled to the first plate in the heel region, opposite the upper. The third midsole portion can be spaced from the first midsole portion and the second midsole portion by a gap, which can extend from a lateral side to a medial side in the midfoot region.

In some embodiments, the beam can be integrally formed with at least one of the first plate or the second plate. The second plate can be configured as an outsole that can include at least one ground engaging element extending from a bottom surface of the second plate.

In some embodiments, the beam can be configured to allow the first plate and the second plate to pivot by a first maximum angular rotation in a first direction and by a second maximum angular rotation in a second direction. Each of the first maximum angular rotation and the second maximum angular rotation can be between about 10 degrees and about 30 degrees. In some cases, the first maximum angular rotation can be different from the second maximum angular rotation.

According to another aspect, the present disclosure provides a sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region. The sole structure can include an upper plate and a lower plate that can be spaced from and pivotably coupled with the upper plate by a beam. The beam can be configured to allow the upper plate and lower plate to rotate relative to one another toward each of a lateral side and a medial side of the sole structure. A first midsole portion can be disposed on the lateral side of the beam. The first midsole portion can be coupled to each of the upper plate and the lower plate so that the relative rotation of the upper plate and the lower plate causes the first midsole portion to deform. The deformation of the first midsole portion can provide a first resistive force that opposes the relative rotation of the upper and lower plates. A second midsole portion can be disposed on the medial side of the beam. The second midsole portion can be coupled to each of the upper plate and the lower plate so that the relative rotation of the upper plate and the lower plate causes the second midsole portion to deform. The deformation of the second midsole portion can provide a second resistive force that opposes the relative rotation of the upper and lower plates.

In some embodiments, each of the lower plate, the first midsole portion, and the second midsole portion can extend from a first end in the forefoot region to a second end in the midfoot region. In some cases, the beam can be aligned along a longitudinal axis of the sole structure and can be disposed entirely within the forefoot region. The beam can be configured to allow the upper plate and the lower plate to rotate relative to one another by a maximum angular rotation that can be between about 15 degrees and about 35 degrees.

According to yet another aspect, the present disclosure provides a sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region. The sole structure can include an upper plate that can be configured to couple to the upper and that can extend from the forefoot region, through the midfoot region, to the heel region. A forefoot portion can be positioned predominately in the forefoot region and a heel portion positioned predominately in the forefoot region, and the forefoot portion and the heel portion can be spaced apart from one another by a gap in the midfoot region. The forefoot portion can include a first lower plate that can be spaced from and pivotably coupled with the upper plate by a beam. The beam can be configured to allow the upper plate and lower plate to rotate relative to one another toward each of a lateral side and a medial side of the sole structure. A first midsole portion can be positioned between the upper plate and the first lower plate. The first midsole portion can at least partially surround the beam, such that the first midsole portion includes a lateral midsole portion positioned along a lateral side of the beam and a medial midsole portion disposed along a medial side of the beam. The heel portion can include a second lower plate and a second midsole member than can be positioned between the upper plate and the second lower plate.

In some embodiments, the lateral midsole portion and the medial midsole portion can each be coupled to both the upper plate and the first lower plate.

In some embodiments, the first lower plate can be configured as a first outsole portion and the second lower plate can be configured as a second outsole portion.

Other aspects of the articles of footwear described herein, including features and advantages thereof, will become apparent to one of ordinary skill in the art upon examination of the figures and detailed description herein. Therefore, all such aspects of the articles of footwear are intended to be included in the detailed description and this summary.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a top, front, and lateral perspective view of a sole structure for an article of footwear according to aspects of the disclosure;

FIG.2 is a lateral side view of the sole structure ofFIG.1 with an upper of the article of footwear shown in phantom;

FIG.3 is a medial side view of the sole structure of FIG. with an upper of the article of footwear shown in phantom;

FIG.4 is a top plan view of the sole structure ofFIG.1;

FIG.5 is a cross sectional view of the sole structure ofFIG.1 taken along line A-A;

FIG.6 is a cross sectional view of the sole structure ofFIG.5 with the sole structure being compressed along a lateral side; and

FIG.7 is a cross-sectional view of another sole structure with the sole structure being compressed along a lateral side.

DETAILED DESCRIPTION OF THE DRAWINGS

The following discussion and accompanying figures disclose various embodiments or configurations of a shoe having an upper and a sole structure. Although embodiments are disclosed with reference to a sports shoe, such as a running shoe, tennis shoe, basketball shoe, etc., concepts associated with embodiments of the shoe may be applied to a wide range of footwear and footwear styles, including basketball shoes, cross-training shoes, football shoes, golf shoes, hiking shoes, hiking boots, ski and snowboard boots, soccer shoes and cleats, walking shoes, and track cleats, for example. Concepts of the shoe may also be applied to articles of footwear that are considered non-athletic, including dress shoes, sandals, loafers, slippers, and heels.

The term “about,” as used herein, refers to variations in the numerical quantity that may occur, for example, through typical measuring and manufacturing procedures used for articles of footwear or other articles of manufacture that may include embodiments of the disclosure herein; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients used to make the compositions or mixtures or carry out the methods; and the like. Throughout the disclosure, the terms “about” and “approximately” refer to a range of values ± 5% of the numeric value that the term precedes.

Also as used herein, unless otherwise limited or defined, “or” indicates a non- exclusive list of components or operations that can be present in any variety of combinations, rather than an exclusive list of components that can be present only as alternatives to each other. For example, a list of “A, B, or C” indicates options of: A; B; C; A and B; A and C; B and C; and A, B, and C. Correspondingly, the term “or” as used herein is intended to indicate exclusive alternatives only when preceded by terms of exclusivity, such as “only one of,” or “exactly one of.” For example, a list of “only one of A, B, or C” indicates options of: A, but not B and C; B, but not A and C; and C, but not A and B. In contrast, a list preceded by “one or more” (and variations thereon) and including “or” to separate listed elements indicates options of one or more of any or all of the listed elements. For example, the phrases “one or more of A, B, or C” and “at least one of A, B, or C” indicate options of: one or more A; one or more B; one or more C; one or more A and one or more B; one or more B and one or more C; one or more A and one or more C; and one or more A, one or more B, and one or more C. Similarly, a list preceded by “a plurality of” (and variations thereon) and including “or” to separate listed elements indicates options of multiple instances of any or all of the listed elements. For example, the phrases “a plurality of A, B, or C” and “two or more of A, B, or C” indicate options of: one or more A and one or more B; one or more B and one or more C; one or more A and one or more C; and one or more A, one or more B, and one or more C.

Further, as used herein, unless otherwise defined or limited, directional terms are used for convenience of reference for discussion of particular figures or examples. For example, references to “downward,” or other directions, or “lower” or other positions, may be used to discuss aspects of a particular example or figure, but do not necessarily require similar orientation or geometry in all installations or configurations.

The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and/or sections. These elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer, or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example configurations.

The present disclosure relates to an article of footwear with a sole structure attached to an upper. The sole structure includes an upper plate that is coupled to the upper and outsole that is configured as a lower plate, which defines a bottom of the article of footwear. The upper plate and the lower plate can be spaced from and pivotably coupled with one another by a beam defining a length that is approximately parallel to a length of the article of footwear (i.e., a dimension taken along heel-to-toe direction). Accordingly, the upper plate and the lower plate can rotate about the length of the beam and the beam can provide a resistive moment that can oppose and control the movement (i.e., rotation) between the upper plate and the lower plate. In some embodiments, the upper plate, the lower plate, and the beam can be disposed within the forefoot region; however, other configurations are possible. Additionally, in some embodiments, the upper plate, the lower plate, and the beam can be co-molded to form a single unitary body, or they may be configured as separate components that can be coupled to one another, for example, by fasteners or an adhesive.

In some embodiments, a sole structure can further include a midsole that is disposed between an upper plate and a lower plate that are pivotably coupled by a beam. More specifically, at least a portion of the midsole is disposed along each of a lateral side of the beam and a medial side of the beam. In some cases, the midsole can at least partially surround the beam along its sides (e.g., the sides of the beam extending between the upper and lower plates), such that a first portion of the midsole is positioned along a lateral side of the beam and so that a second portion of the midsole is positioned along a medial side of the beam. The midsole can be made from, for example, a foam material (e.g., EVA) to provide cushioning for the user. Accordingly, as the upper plate and the lower plate rotate about the beam, at least a portion of the midsole can be compressed between the upper and lower plates. Thus, due to the resilient nature of material of the midsole, the midsole provides an opposing force that resists the movement between the upper and lower plates, thereby controlling the movement by acting as a dampener. In that regard, the specific material properties of the midsole can be chosen to tune the midsole for specific dampening and cushioning characteristics.

For example, in some embodiments, the midsole can be a multi-density midsole with two or more portions that can be configured to provide different amounts of cushioning. In particular, a midsole can include a first or lateral midsole portion that is disposed on a lateral side of the flexible member and a second or medial midsole portion that is disposed on a medial side of the flexible member. The lateral midsole member can have a low density to impart the lateral side of the sole structure with enhanced flexibility and cushioning, while the medial midsole member can have a comparatively high density to impart the medial side of the sole structure with increased stability. Correspondingly, such an arrangement can help to reduce pronation. In other embodiments, the midsole can be configured differently, for example, to help reduce pronation in one foot of a user while reducing supination in the other foot.

In addition to reducing pronation and supination, by allowing the upper and lower plates to rotate about the beam relative to one another, the sole structure can provide improved traction when moving along a curve, wherein a user’s body naturally leans into a turn, and when moving along uneven or sloped surfaces. In particular, the articulation of the upper and lower plates about the beam can compress a portion of the midsole (e.g., a lateral or medial side), while expanding (e.g., stretching) another portion of the midsole (e.g., the medial or lateral side, respectively), thereby allowing the lower plate to remain approximately parallel with the ground, thereby creating the largest possible contact patch therebetween.

FIGS.1-6 depict an exemplary embodiment of an article offootwear100 including an upper102 (shown in phantom inFIGS.2-5) and asole structure104, with thesole structure104 being configured to extend between the upper102 and the ground. For reference, as illustrated inFIGS.1-4, in particular, the article offootwear100 generally defines aforefoot region120, amidfoot region122, and aheel region124. Theforefoot region120 generally corresponds with portions of the article offootwear100 that encase portions of the foot that include the toes, the ball of the foot, and joints connecting the metatarsals with the toes or phalanges. Themidfoot region122 is proximate and adjoining theforefoot region120, and generally corresponds with portions of the article offootwear100 that encase the arch of a foot, along with the bridge of a foot. Theheel region124 is proximate and adjoining themidfoot region122 and generally corresponds with portions of the article offootwear100 that encase rear portions of the foot, including the heel or calcaneus bone, the ankle, or the Achilles tendon.

The article offootwear100 also defines alateral side126, and amedial side128. Further, the article offootwear100 defines alongitudinal axis130 that extends from atoe end132 that is located at a distal end of theforefoot region120, to aheel end134 that is located at a distal end of theheel region124, opposite thetoe end132. Thelongitudinal axis130 defines a middle of the article offootwear100 with thelateral side126 extending from one side of thelongitudinal axis130 and themedial side128 extending from the other. Put another way, thelateral side126 and themedial side128 adjoin one another along thelongitudinal axis130. In particular, thelateral side126 corresponds to an outside portion of the article offootwear100 and themedial side128 corresponds to an inside portion of the article offootwear100. As such, left and right articles of footwear have opposing lateral126 and medial128 sides, such that themedial sides128 are closest to one another when a user is wearing the article offootwear100, while thelateral sides126 are defined as the sides that are farthest from one another while being worn.

Theforefoot region120, themidfoot region122, theheel region124, themedial side128, and thelateral side126 are intended to define boundaries or areas of the article offootwear100, and collectively span an entire length of the article offootwear100, from thetoe end132 to theheel end134. It should be appreciated that aspects of the disclosure may refer to portions or elements that are coextensive with one or more of theforefoot region120, themidfoot region122, theheel region124, themedial side128, or thelateral side126. Theforefoot region120 extends from thetoe end132 to awidest portion136 of the article of footwear100 (i.e., a distance between themedial side128 and thelateral side126 of the sole structure104). Themidfoot region122 extends from thewidest portion136 to athinnest portion138 of the article of footwear100 (i.e., a distance between themedial side128 and thelateral side126 of the sole structure104). Theheel region124 extends from thethinnest portion138 to theheel end134 of the article offootwear100.

Thelateral side126 begins where thetoe end132 intersects thelongitudinal axis130 and bows outward (i.e., away from the longitudinal axis130) along theforefoot region120 toward themidfoot region122. At thewidest portion136, thelateral side126 bows inward (i.e., toward the longitudinal axis130) toward thethinnest portion138, entering themidfoot region122. Upon reaching thethinnest portion138, thelateral side126 bows outward and extends into theheel region124. Thelateral side126 then bows back inward toward theheel end134 and terminates where theheel end134 intersects with thelongitudinal axis130. Similarly, themedial side128 begins where thetoe end132 intersects thelongitudinal axis130 and bows outward (i.e., away from the longitudinal axis130) along theforefoot region120 toward themidfoot region122. At thewidest portion136, themedial side128 bows inward (i.e., toward the longitudinal axis130) toward thethinnest portion138, entering themidfoot region122. Upon reaching thethinnest portion138, themedial side128 bows outward and extends into theheel region124. Themedial side128 then bows back inward toward theheel end134 and terminates where theheel end134 intersects with thelongitudinal axis130.

It should be understood that numerous modifications may be apparent to those skilled in the art in view of the foregoing description, and individual components thereof, may be incorporated into numerous articles of footwear. Accordingly, aspects of the article offootwear100 and components thereof, may be described with reference to general areas or portions of the article offootwear100, with an understanding the boundaries of theforefoot region120, themidfoot region122, theheel region124, thelateral side126, and/or themedial side128 as described herein may vary between articles of footwear. Furthermore, aspects of the article offootwear100 and individual components thereof, may also be described with reference to exact areas or portions of the article offootwear100 and the scope of the appended claims herein may incorporate the limitations associated with these boundaries of theforefoot region120, themidfoot region122, theheel region124, thelateral side126, and/or themedial side128 discussed herein.

With continued reference toFIGS.1-4, the upper102 can be configured to at least partially enclose the foot of a user and may be made from one or more materials. As illustrated, the upper102 is disposed above and coupled to the sole structure104 (seeFIGS.2 and3), and can extend along the entirety of each of thelateral side126 and themedial side128, as well as extending over the top of theforefoot region120 and around theheel region124. Accordingly, the upper102 defines an interior cavity140 (seeFIGS.5 and6) into which a foot of a user may be inserted. The upper102 can be formed from one or more layers. For example, many conventional uppers are formed from multiple elements (e.g., textiles, polymer foam, polymer sheets, leather, and synthetic leather) that are joined through bonding or stitching at a seam. In various embodiments, a knitted component may incorporate various types of yarn that may provide different properties to an upper. In other embodiments, the upper may incorporate multiple layers of different materials, each having different properties, for example, increased breathability or moisture wicking.

A number of other features may also be coupled to or included in an upper to provide or enhance certain properties of the upper. For example, an upper can include a tongue (not shown) that may include a tongue lining and/or a foam pad to increase comfort. The tongue may be a separate component that is attached to the upper or it may be integrally formed with one or more layers of the upper. Additionally, an upper can also include a tensioning system123 that allows a user to adjust the upper to fit a foot of a user. The tensioning system123 can extend through themidfoot region122 and/or theforefoot region120 of the upper102 and may be attached to the upper102 by an attachment structure. For example, an upper may include a plurality of holes (e.g., punch holes) and/or eyelets that are configured to slidably receive laces so that the user can secure (e.g., by tightening and tying the laces) the article of footwear to a foot. In other embodiments, a tensioning system may be another laceless fastening system known in the art.

Furthermore, an upper can include an insole (not shown) positioned within an interior cavity, which can be in direct contact with a user’s foot while an article of footwear is being worn. Moreover, an upper may also include a liner (not shown) that can increase comfort, for example, by reducing friction between the foot of the user and the upper, and/or providing moisture wicking properties. The liner may line the entirety of interior cavity or only a portion thereof. In other embodiments, a binding (not shown) may surround the opening of the interior cavity to secure the liner to the upper and/or to provide an aesthetic element on the article of footwear.

As mentioned above, thesole structure104 is disposed below the upper102 and extends between the upper102 and the ground to support the foot of a user. In general, thesole structure104 includes amidsole144 disposed above anoutsole146 that defines abottom surface148 of the article offootwear100. Themidsole144 is the portion of thesole structure104 that is disposed between the upper102 and theoutsole146 and provides cushioning for a user by absorbing the impact that occurs when the user’s foot contacts the ground. Accordingly, themidsole144 acts as a cushioning member for the article of footwear. In some cases, multiple cushioning members can be provided, which can collectively form the midsole, to impart specific cushioning properties at different regions of the sole structure, in theforefoot region120, themidfoot region122, theheel region124, thelateral side126, or themedial side128. To provide the desired cushioning characteristics, the thickness of the midsole144 (e.g., a dimension taken along a direction that is normal to the bottom surface148) can be varied, with thicker regions providing greater cushioning and stability, and thinner regions providing less cushioning and greater flexibility.

Additionally,midsole144, including any individual cushioning members that collectively form themidsole144, can be made of one or more materials to provide themidsole144 with the desired cushioning characteristics. For example, a cushioning member of a midsole may be individually constructed from a thermoplastic material, such as polyurethane (PU), for example, and/or an ethylene-vinyl acetate (EVA), copolymers thereof, or a similar type of material. In other embodiments, cushioning members of a midsole may be an EVA-Solid-Sponge (“ESS”) material, an EVA foam (e.g., PUMA® ProFoam Lite™, IGNITE Foam), polyurethane, polyether, an olefin block copolymer, a thermoplastic material (e.g., a thermoplastic polyurethane, a thermoplastic elastomer, a thermoplastic polyolefin, etc.), or a supercritical foam. A cushioning member may be a single polymeric material or may be a blend of materials, such as an EVA copolymer, a thermoplastic polyurethane, a polyether block amide (PEBA) copolymer, and/or an olefin block copolymer. One example of a PEBA material is PEBAX®.

In embodiments where a cushioning member is formed from a supercritical foaming process, the supercritical foam may comprise micropore foams or particle foams, such as a TPU, EVA, PEBAX®, or mixtures thereof, manufactured using a process that is performed within an autoclave, an injection molding apparatus, or any sufficiently heated/pressurized container that can process the mixing of a supercritical fluid (e.g., CO₂, N₂, or mixtures thereof) with a material (e.g., TPU, EVA, polyolefin elastomer, or mixtures thereof) that is preferably molten. During an exemplary process, a solution of supercritical fluid and molten material is pumped into a pressurized container, after which the pressure within the container is released, such that the molecules of the supercritical fluid rapidly convert to gas to form small pockets, e.g., pockets of nitrogen gas, within the material and cause the material to expand into a foam, which may be used as the cushioning member. In further embodiments, a first cushioning member may be formed using alternative methods known in the art, including the use of an expansion press, an injection machine, a pellet expansion process, a cold foaming process, a compression molding technique, die cutting, or any combination thereof. For example, a first cushioning member may be formed using a process that involves an initial foaming step in which supercritical gas is used to foam a material and then compression molded or die cut to a particular shape.

Theoutsole146 is disposed below themidsole144 and is configured to contact the ground along thebottom surface148. Accordingly, theoutsole146 can be made of a comparatively tough material that can resist wear and provide traction for a user, for example, rubber (natural or synthetic) or rubber-like compounds and composites. Additionally, to further improve traction, some embodiments can include a plurality ofground engaging protrusions150, e.g., lugs or spikes.

In the illustrated embodiment, thesole structure104 is configured as an articulable, i.e., flexible, sole structure that can flex perpendicularly to thelongitudinal axis130. Because thesole structure104 can flex perpendicularly to thelongitudinal axis130, thebottom surface148 of thesole structure104 can be approximately parallel with the ground, even where the ground is sloped or the article offootwear100 is tilted, e.g., when running along a curve, so that there is a non-zero angle between the ground and thebottom surface148. Put another way, thesole structure104 can flex so that, when thebottom surface148 and the ground are not in contact and there is a non-zero angle therebetween, any subsequent contact between thebottom surface148 and the ground causes thesole structure104 to flex so thatbottom surface148 is approximately parallel with the ground. In this way, thebottom surface148 can contact the ground along an entire width, e.g., a dimension extending between thelateral side126 and themedial side128, of thebottom surface148.

To secure theforefoot portion152 and theheel portion154 in this spaced relationship, each of theforefoot portion152 and theheel portion154 are fixedly coupled to anupper plate160. Theupper plate160 defines an upper surface of thesole structure104, which is configured to couple to the upper102. Accordingly, each of theforefoot portion152 and theheel portion154 extend downwardly, e.g., away from the upper102, from theupper plate160 to make contact with the ground. As illustrated, theupper plate160 is configured as a curved plate, with a concave side facing upward toward the upper102 (seeFIGS.5 and6). In addition, theupper plate160 extends along the length of thesole structure104, between thetoe end132 and theheel end134, and throughout aforefoot region120, amidfoot region122, and aheel region124. In other embodiments, theupper plate160 can be configured differently. For example, theupper plate160 can be curved differently or be flat, and may only extend along a portion of thesole structure104.

Theforefoot portion152 is configured to allow thesole structure104 to flex perpendicularly to thelongitudinal axis130 of the article offootwear100. In particular, theforefoot portion152 includes a first outsole portion configured as a firstlower plate164. Correspondingly, in some cases, the firstlower plate164 can include one or moreground engaging elements150, e.g., cleats, studs, or spikes, that depend from a bottom surface of the firstlower plate164 to engage with the ground, thereby improving traction. In some cases, a separate outsole portion can be coupled to a lower surface of the firstlower plate164, such as to reduce wear on the firstlower plate164 and increase traction for a user.

The firstlower plate164 is spaced from and pivotably coupled with theupper plate160 by abeam166. That is, the firstlower plate164 is spaced below theupper plate160 to define agap165 therebetween and thebeam166 extends across the gap to couple the firstlower plate164 and theupper plate160 together. Depending on the shape of the

plates

160,164, thegap165 may be a constant or it may vary. For example, as illustrated inFIG.5, the curvature of theupper plate160 causes thegap165 to increase moving outward from thebeam166 to each of the lateral and

medial sides

126,128. Accordingly, due to thegap165, theupper plate160 and the firstlower plate164 can pivot relative to one another via thebeam166, in either a medial or a lateral direction. For example, and as will be described in greater detail below, theupper plate160 and the firstlower plate164 can pivot in a lateral direction, i.e., a first direction, to bring their respective lateral sides closer together, while moving their respective medial sides farther apart, or in a medial direction, i.e., a second direction, to bring their respective medial sides closer together, while moving their respective lateral sides farther apart.

As shown inFIG.1, the beam can be disposed entirely within theforefoot region120. However, it is also possible that thebeam166 may extend from theforefoot region120 and into either of themidfoot region122 or theheel region124.

In general, thesole structure104, e.g., thebeam166, can be configured to allow theupper plate160 and the firstlower plate164 to rotate relative to one another by a predetermined amount. For example, of theupper plate160, the firstlower plate164, and the beam166 (seeFIG.5), theupper plate160 and the first lower plate can be permitted to rotate relative to one another by a first maximum angular rotation in a first rotational direction and to rotate by up to a second maximum angular rotation in a second rotational direction. For example, relative to an unflexed or neutral state in which theupper plate160 and thelower plate164 are at afirst angle181 relative to one another (seeFIG.5), theupper plate160 and thelower plate164 can rotate away from the neutral state to be at asecond angle183 relative to one another (seeFIG.6), where the angular rotation is the magnitude of the difference between thefirst angle181 and thesecond angle183.

The first and second maximum angular rotations may be the same angular rotations or different angular rotations, such that the first maximum angular rotation is greater than or less than the second angular rotation. Accordingly, each of the first and second maximum angular rotations may range between about 5 degrees and about 45 degrees, or more specifically, about 45 degrees, about 40 degrees, about 35 degrees, about 30 degrees, about 25 degrees, about 20 degrees, about 15 degrees, about 10 degrees, about 5 degrees, or any ranges therein (e.g., between about 15 degrees and about 30 degrees, between about 10 degrees and about 20 degrees, etc.).

Thebeam166 is configured as a linear, elongate member with a length167 (seeFIGS.1 and4) that is oriented in a heel-to-toe direction, e.g., approximately parallel with thelongitudinal axis130, and a width169 (seeFIG.4) that is perpendicular to thelength167 in a lateral-to-medial direction. Further, thebeam166 defines aheight171 between theupper plate160 and the firstlower plate164, which is perpendicular to both thelength167 and thewidth169. Thebeam166 is an elongate beam in which thelength167 is greater than both thewidth169 and theheight171. In particular, thelength167 can be at least 150%, 200%, 300%, or 400% of one of thewidth169 or theheight171. Additionally, it may be preferrable that, depending on the desired bending or flexing characteristics of the beam, theheight171 is greater than equal to the width, for example, to be at least 100%, 150%, or 300% of thewidth169, as may allow for greater bending of thebeam166.

Further, as shown inFIG.4, thebeam166 is generally aligned with thelongitudinal axis130 to be centered between the lateral and

medial sides

126,128 of thesole structure104. In some cases, thebeam166 may be biased to be closer to one of thelateral side126 or themedial side128, as it may allow thesole structure104 to more easily flex to either thelateral side126 or themedial side128.

Due to the elongate shape of thebeam166, theupper plate160 and the firstlower plate164 can rotate (e.g., pivot or hinge) about the length thebeam166, e.g., about an axis extending along the length of the beam166), while remaining rigid in a heel-to-toe direction. Depending on the specific characteristics of the beam166 (e.g., material properties, size, etc.), thebeam166 may flex along itsheight171, e.g., a distance between theupper plate160 and the firstlower plate164, or theupper plate160 or the firstlower plate164 may flex about their respective connections to thebeam166.

Thebeam166 can provide a resistive moment that can help to control the movement (i.e., rotation) of theupper plate160 and the firstlower plate164. The moment provided by thebeam166 can be tuned in a number of ways. For example, modifying material properties of thebeam166 can either increase (e.g., by using a stiffer material) or decrease (e.g., by using a softer, less stiff material) the resistive moment that can be provided by thebeam166. Similarly, increasing the width and/or length, and decreasing the height of thebeam166 can increase the resistive moment that can be provided by thebeam166, while decreasing the width and/or length, and increasing the height can decrease the resistive moment that can be provided by thebeam166. In other embodiments, other modifications to thebeam166 can also affect the resistance that can be provided by thebeam166, for example, by including longitudinal grooves along the length of thebeam166, or projections that extend in a medial-to-lateral direction from thebeam166.

Further, the shape of thebeam166 can also be adjusted to provide a specific bending characteristic, for example, to have an equal resistance to bending in both the lateral and medial directions, or to have different resistance to bending in each of the lateral and medial directions. Further still, the cross sectional shape of thebeam166 can tuned to provide a desired bending characteristic. For example, as is best shown inFIGS.5 and6, thebeam166 can have a generally rectangular cross-sectional shape. In other embodiments, other cross-sectional shapes can also be used, including, trapezoids, parallelograms, hourglass-like (e.g., with inwardly curving sides), ellipsoids, or other types of cross-sectional shapes.

Moreover, the position of thebeam166 can also affect the resistance that can be provided by thebeam166. For example, in the illustrated embodiment, thebeam166 is disposed approximately in the center of theforefoot region120. That is, thebeam166 is disposed between the lateral and

medial sides

126,128 so that a central axis running along the length of the beam is aligned with thelongitudinal axis130 of the article offootwear100, and so that thebeam166 is approximately equidistant from each of thetoe end132 of theforefoot region120 and theheel end134 of theforefoot region120. Accordingly, thebeam166 can provide the same effective resistance when theupper plate160 and the firstlower plate164 rotate to come together on thelateral side126, as when theupper plate160 and the firstlower plate164 rotate to come together on themedial side126. However, if thebeam166 were biased so as to be closer to thelateral side126 than to themedial side128, thebeam166 would provide a greater effective resistance when theupper plate160 and the firstlower plate164 rotate to come together on thelateral side126, as compared to when theupper plate160 and the firstlower plate164 rotate to come together on themedial side128.

As illustrated inFIGS.5 and6, theupper plate160, the firstlower plate164, and thebeam166 can be integrally formed with one another. For example, in some cases, theupper plate160, the firstlower plate164, and thebeam166 can be formed as unitary body using an injection or compression molding process. Accordingly, theupper plate160, the firstlower plate164, and thebeam166 can be made from a polymeric material, for example, TPU. In other cases, as may be determined by a specific use of the article offootwear100, the one or more of theupper plate160, the firstlower plate164, and thebeam166 can be separate components that are coupled together. For example, theupper plate160 or the firstlower plate164 can be a carbon fiber or other type of composite plate to provide rigidity and reduce weight, while thebeam166 can be made from a comparatively softer, more flexible material, such as TPU, to promote bending and flexing to allow theupper plate160 and the firstlower plate164 to pivot relative to one another. In still other embodiments, other combinations are possible, for example, theupper plate160 can be a separate composite plate, while thebeam166 and the firstlower plate164 can be integrally formed.

Additionally, theforefoot portion152 can include afirst midsole portion168 that can provide further resistance to oppose the movement between theupper plate160 and the firstlower plate164, as well as to provide cushioning. As illustrated, thefirst midsole portion168 is disposed between theupper plate160 and the firstlower plate164, and is configured to at least partially surround thebeam166. Accordingly, a first part of thefirst midsole portion168, i.e., a lateral portion, can be positioned on a lateral side of thebeam166 to be between thebeam166 and a lateral edge of thesole structure102, and a second part of thefirst midsole portion168, i.e., a medial portion, can be positioned on a medial side of thebeam166 to be between thebeam166 and a medial edge of thesole structure102. In some cases, thefirst midsole portion168 may be in contact with thebeam166; however, this may not always be the case.

As mentioned above, thefirst midsole portion168 provides cushioning, whereby thefirst midsole portion168 can compress or expand (i.e., stretch) in response to an impact. Accordingly, thefirst midsole portion168 can deform in response to the relative movement of theupper plate160 and the firstlower plate164 and can provide a corresponding opposing force that resists such movement.

For example, with specific reference toFIG.3, when an external force170 (i.e., pressure) is applied along thelateral side126 of one or both of theupper plate160 and the firstlower plate164, e.g., as may occur when a user takes a step, theupper plate160 and the firstlower plate164 are brought together along thelateral side126. Accordingly, where the first midsole is coupled to both theupper plate160 and the firstlower plate164, a firstlateral midsole portion176, i.e., thelateral side126 of thefirst midsole portion168, is compressed. At the same time, since theupper plate160 and the firstlower plate164 can each rotate about thebeam166, theupper plate160 and the firstlower plate164 are moved apart from one another along themedial side128, thereby stretching a firstmedial midsole portion178, i.e., amedial side128 of thefirst midsole portion168. The inverse occurs where pressure is applied to themedial side128, such that the firstlateral midsole portion176 is stretched and the firstmedial midsole portion178 is compressed. As mentioned above, in some cases, the firstlateral midsole portion176 and the firstmedial midsole portion178 can be separate midsole portions that collectively form thefirst midsole portion168. Correspondingly, movement of the

plates

160,164 relative to one another also changes the magnitude of thegap165 on each side of thebeam166.

Due to the resilient nature of the material of thefirst midsole portion168, thefirst midsole portion168 produces resistive forces at each of the firstlateral midsole portion176 and the firstmedial midsole portion178. More specifically, the compression of the firstlateral midsole portion176 produces a firstresistive force172 that acts in the opposite direction of theexternal force170 to push theupper plate160 and the firstlower plate164 apart on thelateral side126. Conversely, the expansion (i.e., stretching) of the firstmedial midsole portion178 produces a secondresistive force174 that acts in the same direction as theexternal force170 to pull theupper plate160 and the firstlower plate164 together on themedial side128. In this way, the

resistive forces

172,174 provided by thefirst midsole portion168 create a moment that acts in conjunction with the moment provided by thebeam166 to counteract theexternal force170.

In other embodiments, it is possible that thefirst midsole portion168, i.e., either of the firstlateral midsole portion176 or the firstmedial midsole portion178, are only coupled to one of theupper plate160 or the firstlower plate164. In such cases, deformation of the firstlateral midsole portion176 or the firstmedial midsole portion178 may only occur by compression on the side where the respective portions of the

plates

160,164 are moved together, e.g., on thelateral side126 or themedial side128. Conversely, on the opposing side, .i.e., the other of thelateral side126 or themedial side128, where the respective portions of the

plates

160,164 are moved apart, the unconnected plate can move independently away from thefirst midsole portion168, so as not to cause stretching of the respective part of thefirst midsole portion168.

In some cases, thefirst midsole portion168 can be comprised of multiple portions, i.e., sub-portions. For example, the firstlateral midsole portion176 and the firstmedial midsole portion178, which are disposed along thelateral side126 and themedial side128 of thebeam166, respectively, can be configured as separate portions. Each of the firstlateral midsole portion176 and the firstmedial midsole portion178 can be made from the same or different materials to allow the flexibility of thesole structure104 to be tailored for a specific application or purpose. For example, the firstlateral midsole portion176 can be made from a material having a lower density than the firstmedial midsole portion178, or vice versa. This difference in material density can allow theforefoot portion152 to have differing amounts of flexibility to rotate in each direction.

That is, different material properties in the

midsole portions

176,178 can result in one of thelateral side126 or themedial side128 having a different spring constant or speed of recovery than the other. As a result, one side may be more difficult to deform, i.e., require greater force to cause an equivalent deformation, or may recover to its original shape faster than the other side As one particular example, where the firstlateral midsole portion176 has a lower density than the firstmedial midsole portion178, thelateral side126 can remain more flexible than themedial side128, making it easier, e.g., by requiring less force, for theupper plate160 and the firstlower plate164 to rotate to come together on thelateral side126, as shown inFIG.3, as compared with themedial side128. This arrangement can be beneficial in reducing pronation of a foot of a user. In other embodiments, the firstlateral midsole portion176 and the firstmedial midsole portion178 can be configured differently, for example, to reduce supination.

Additionally, in some cases, materials of the firstlateral midsole portion176 and the firstmedial midsole portion178 can be selected to be more flexible in the same direction, e.g., so that a left shoe is more flexible to rotate to a lateral side and so that a corresponding right shoe is more flexible to rotate to a medial side. This may be particularly beneficial in, for example, sports shoes, such as track spikes, which can be configured for use on banked track surfaces with a known angle or range of angles. To that end, the firstlateral midsole portion176 and the firstmedial midsole portion178 can be tuned to easily flex within a predetermined angular range, e.g., between about 0 degrees and about 18 degrees from an unflexed state in a first rotational direction, and to be more resilient to flexing outside of that predetermined angular range, e.g., greater than about 18 degrees or less than about 0 degrees from the unflexed state in the first rotational direction, i.e., to rotate in a second, opposite direction. To allow for such variable resistance, the firstlateral midsole portion176 or the firstmedial midsole portion178 can be a multiple density cushioning element.

As compared with theforefoot portion152, theheel portion154 is not specifically configured to flex perpendicularly to thelongitudinal axis130 of the article offootwear100, although it may do so in some cases. That is, theheel portion154 includes a second outsole portion configured as a secondlower plate180 that is spaced from theupper plate160. However, the secondlower plate180 is not pivotably coupled with theupper plate160 by a beam. Rather, the secondlower plate180 is coupled with theupper plate160 by asecond midsole portion182 that extends between the secondlower plate180 and theupper plate160. In this regard, theheel portion154 functions in a manner that is similar to a conventional midsole in providing cushioning for a foot of a user.

However, in other embodiments, theheel portion154 can be configured similarly to theforefoot portion152, as described above. That is, a heel portion of a sole structure can be configured similarly to theforefoot portion152 in that it can include a beam and a midsole that is positioned on each of a medial side and a lateral side of the beam, as described above, to provide resistance to bending. Accordingly, a heel portion can also be configured to maintain a corresponding outsole portion in contact with the ground during a heel strike by allowing an upper plate and a lower plate to pivot relative to one another about a beam connecting therebetween.

In yet other embodiments, a sole structure for an article of footwear may not include separate and discrete portions, e.g., theforefoot portion152 and theheel portion154. Instead, a sole structure can include an upper plate and an outsole configured as a lower plate, which are joined by a midsole. Accordingly, each of an upper plate, a lower plate, and a midsole can extend throughout a forefoot region, a midfoot region, and a heel region. However, such a sole structure may still include a beam that extends between and connects the upper plate to the lower plate to help guide the sole structure, or portions thereof, to flex perpendicularly to a longitudinal axis of the article of footwear, as described above.

FIG.7 shows a similarsole structure204 that can be used with the article offootwear100. In general, thesole structure204 is configured similarly to thesole structure104 in accordance with the description above. However, as shown, the firstlateral midsole portion176 is a first cushioning member made of a first material having a first density and the firstmedial midsole portion178 is a second cushioning member made of a second material having a second density. The first and second materials can be different from one another, i.e., have different chemical compositions) or they can be the same material. Likewise, the first and second densities can be different from one another or the same. The firstlateral midsole portion176 and the firstmedial midsole portion178 can be connected together, e.g., by an adhesive or comolding, or spaced apart from one another. Additionally, as similarly described above, each of the firstlateral midsole portion176 and the firstmedial midsole portion178 are shown being coupled to only the firstlower plate164. Accordingly, when compressed to thelateral side126, the firstlateral midsole portion176 is compressed between theupper plate160 and the firstlower plate164 on thelateral side126, and theupper plate160 moves away from the firstmedial midsole portion178 to define agap189 therebetween on themedial side128, such that the firstmedial midsole portion178 remains in an uncompressed state.

Additionally, theupper plate160 is made of a first material, e.g., a polymeric or composite material, and the firstlower plate164 andbeam166 are integrally formed from a polymeric material. Further, aseparate outsole246 is coupled to a lower surface of the firstlower plate164 to provide a ground contacting surface.

Any of the embodiments described herein may be modified to include any of the structures or methodologies disclosed in connection with different embodiments. For example, certain features and combinations of features that are presented with respect to particular embodiments in the discussion above can be utilized in other embodiments and in other combinations, as appropriate. Similarly, materials or construction techniques, other than those disclosed above, may be substituted or added in some embodiments according to known approaches. Further, the present disclosure is not limited to articles of footwear of the type specifically shown. Still further, aspects of the articles of footwear of any of the embodiments disclosed herein may be modified to work with any type of footwear, apparel, or other athletic equipment.

As noted previously, it will be appreciated by those skilled in the art that while the disclosure has been described above in connection with particular embodiments and examples, the disclosure is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto.

INDUSTRIAL APPLICABILITY

Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.

Claims

We claim:

1. A sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region, the sole structure comprising:

a first plate extending from the forefoot region, through the midfoot region, to the heel region, the first plate being configured to couple to the upper;

a second plate that is spaced from the first plate by a first gap, the second plate being disposed within the forefoot region; and

a beam extending between the first plate and the second plate so that the first plate is pivotally coupled to the second plate by the beam.

2. The sole structure ofclaim 1, wherein the beam is configured as a linear beam that is aligned along a longitudinal axis of the sole structure.

3. The sole structure ofclaim 2, wherein the beam defines a length that is parallel to the longitudinal axis, a width that is perpendicular to the length in a lateral-to-medial direction, and a height between the first plate and the second plate that is perpendicular to both the length and the width, and

wherein the length is greater than the at least one of the width or the height.

4. The sole structure ofclaim 3, wherein the beam has a rectangular cross-section taken perpendicular to the length.

5. The sole structure ofclaim 1, further including a midsole that is disposed between the first plate and the second plate, the midsole including a first midsole portion positioned along a lateral side of the beam and a second midsole portion positioned along a medial side of the beam.

6. The sole structure ofclaim 5, wherein the first midsole portion is a first cushioning member having a first density and the second midsole portion is a second cushioning member having a second density that is different from the first density.

7. The sole structure ofclaim 6, wherein the first midsole portion is coupled to at least one of the first plate or the second plate, and

wherein the second midsole portion is coupled to at least one of the first plate or the second plate.

8. The sole structure ofclaim 5, wherein the midsole further includes a third midsole portion coupled to the first plate in the heel region, opposite the upper, wherein the third midsole portion is spaced from the first midsole portion and the second midsole portion by a gap that extends from a lateral side to a medial side in the midfoot region.

9. The sole structure ofclaim 1, wherein the beam is integrally formed with at least one of the first plate or the second plate.

10. The sole structure ofclaim 1, wherein the second plate is configured as an outsole that includes at least one ground engaging element extending from a bottom surface of the second plate.

11. The sole structure ofclaim 1, wherein the beam is configured to allow the first plate and the second plate to pivot by a first maximum angular rotation in a first direction and by a second maximum angular rotation in a second direction.

12. The sole structure ofclaim 11, wherein each of the first maximum angular rotation and the second maximum angular rotation are between about 10 degrees and about 30 degrees.

13. The sole structure ofclaim 11, wherein the first maximum angular rotation is different from the second maximum angular rotation.

14. A sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region, the sole structure comprising:

an upper plate,

a lower plate that is spaced from and pivotably coupled with the upper plate by a beam that is configured to allow the upper plate and lower plate to rotate relative to one another toward each of a lateral side and a medial side of the sole structure,

a first midsole portion disposed on the lateral side of the beam and coupled to each of the upper plate and the lower plate, wherein the relative rotation of the upper plate and the lower plate causes the first midsole portion to deform, the deformation of the first midsole portion providing a first resistive force that opposes the relative rotation of the upper and lower plates, and

a second midsole portion disposed on the medial side of the beam and coupled to each of the upper plate and the lower plate, wherein the relative rotation of the upper plate and the lower plate causes the second midsole portion to deform, the deformation of the second midsole portion providing a second resistive force that opposes the relative rotation of the upper and lower plates.

15. The sole structure ofclaim 14, wherein each of the lower plate, the first midsole portion, and the second midsole portion extends from a first end in the forefoot region to a second end in the midfoot region.

16. The sole structure ofclaim 15, wherein the beam is aligned along a longitudinal axis of the sole structure and is disposed entirely within the forefoot region.

17. The sole structure ofclaim 14, wherein the beam is configured to allow the upper plate and the lower plate to rotate relative to one another by a maximum angular rotation that is between about 15 degrees and about 35 degrees.

18. A sole structure for an article of footwear having an upper and defining a forefoot region, a midfoot region, and a heel region, the sole structure comprising:

an upper plate extending from the forefoot region, through the midfoot region, to the heel region, the upper plate being configured to couple to the upper;

a forefoot portion positioned predominately in the forefoot region, the forefoot portion including:

a first lower plate that is spaced from and pivotably coupled with the upper plate by a beam that is configured to allow the upper plate and lower plate to rotate relative to one another toward each of a lateral side and a medial side of the sole structure, and

a first midsole portion positioned between the upper plate and the first lower plate, the first midsole portion at least partially surrounding the beam, such that the first midsole portion includes a lateral midsole portion positioned along a lateral side of the beam and a medial midsole portion disposed along a medial side of the beam; and

a heel portion positioned predominately in the heel region, the heel portion including:

a second lower plate, and

a second midsole member positioned between the upper plate and the second lower plate,

wherein the forefoot portion and the heel portion are spaced apart from one another by a gap in the midfoot region.

19. The sole structure ofclaim 18, wherein the lateral midsole portion and the medial midsole portion are each coupled to both the upper plate and the first lower plate.

20. The sole structure ofclaim 18, wherein the first lower plate is configured as a first outsole portion and the second lower plate is configured as a second outsole portion.