US20240057715A1

US20240057715A1 - Sole structure for an article of footwear

Info

Publication number: US20240057715A1
Application number: US18/451,470
Authority: US
Inventors: Lee D. Peyton; Laura E. Flores Sandoval
Original assignee: Nike Inc
Current assignee: Nike Inc
Priority date: 2022-08-22
Filing date: 2023-08-17
Publication date: 2024-02-22

Abstract

A sole structure for an article of footwear includes a heel region, a forefoot region, a fluid-filled chamber and a midsole. The fluid-filled chamber extends from the heel region to the forefoot region. The midsole includes a first projection contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection contacting the fluid-filled chamber at a second contact region in the heel region. The first projection is spaced apart and separated from the second projection to define a gap.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/373,090, filed on Aug. 22, 2022. The disclosure of this prior application is considered part of the disclosure of this application and is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates generally to an article of footwear and, more particularly, to a sole structure for an article of footwear.

BACKGROUND

This section provides background information related to the present disclosure and is not necessarily prior art.
Articles of footwear conventionally include an upper and a sole structure. The upper may be formed from any suitable material(s) to receive, secure, and support a foot on the sole structure. The upper may cooperate with laces, straps, or other fasteners to adjust the fit of the upper around the foot. A bottom portion of the upper, proximate to a bottom surface of the foot, attaches to the sole structure.
Sole structures generally include a layered arrangement extending between a ground surface and the upper. One layer of the sole structure 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 enhance traction with the ground surface. Another layer of the sole structure includes a midsole disposed between the outsole and the upper. The midsole provides cushioning for the foot and may be partially formed from a polymer foam material that compresses resiliently under an applied load to cushion the foot by attenuating ground-reaction forces. The midsole may additionally or alternatively incorporate a fluid-filled bladder to provide cushioning to the foot by compressing resiliently under an applied load to attenuate ground-reaction forces. Sole structures may also include a comfort-enhancing insole or sockliner located within a void proximate to the bottom portion of the upper and a strobel attached to the upper and disposed between the midsole and the insole or sockliner.
Midsoles employing fluid-filled bladders typically include a recess sized and shaped to receive a similarly sized and shaped fluid-filled bladder. The fluid-filled bladders are often constructed to both flex and provide support when compressed resiliently under applied loads, such as during athletic movements. In this regard, fluid-filled bladders are often designed to balance support for the foot with cushioning characteristics that provide responsiveness as the bladder resiliently compresses under an applied load.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected configurations and are not intended to limit the scope of the present disclosure.

FIG. 1 is a side view of an article of footwear in accordance with principles of the present disclosure;

FIG. 2 is an exploded top perspective view of the sole structure of FIG. 1 ;

FIG. 3 is an exploded bottom perspective view of the sole structure of FIG. 1 ;

FIG. 3A is an exploded bottom perspective view of the sole structure of FIG. 1 showing a rearward projection formed as a separate component;

FIG. 3B is an exploded bottom perspective view of the sole structure of FIG. 1 showing a forward projection formed as a separate component;

FIG. 3C is an exploded bottom perspective view of the sole structure of FIG. 1 showing a forward projection and a rearward projection formed as separate components;

FIG. 4 is a front view of the sole structure of FIG. 1 ;

FIG. 5 is a back view of the sole structure of FIG. 1 ;

FIG. 6 is a bottom plan view of the sole structure of FIG. 1 ;

FIG. 7 is a cross-sectional view of the sole structure of FIG. 6 taken along line 7-7;

FIG. 7A is a cross-sectional view of the sole structure of FIG. 7 showing a rearward projection formed as a separate component;

FIG. 7B is a cross-sectional view of the sole structure of FIG. 7 showing a forward projection formed as a separate component;

FIG. 7C is a cross-sectional view of the sole structure of FIG. 7 showing a forward projection and a rearward projection formed as separate components;

FIG. 8 is a cross-sectional view of the sole structure of FIG. 6 , taken along line 8-8;

FIG. 9 is a cross-sectional view of the sole structure of FIG. 6 , taken along line 9-9;

FIG. 10 is a cross-sectional view of the sole structure of FIG. 6 , taken along line 10-10;

FIG. 11 is a side view of a configuration of an article of footwear in accordance with principles of the present disclosure;

FIG. 12 is an exploded top perspective view of the sole structure of FIG. 11 ;

FIG. 12A is an exploded top perspective view of the sole structure of FIG. 11 showing a rearward projection formed as a separate component;

FIG. 12B is an exploded top perspective view of the sole structure of FIG. 11 showing a forward projection formed as a separate component;

FIG. 12C is an exploded top perspective view of the sole structure of FIG. 11 showing a forward projection and a rearward projection formed as separate components;

FIG. 13 is an exploded bottom perspective view of the sole structure of FIG. 11 ;

FIG. 14 is a front view of the sole structure of FIG. 11 ;

FIG. 15 is a back view of the sole structure of FIG. 11 ;

FIG. 16 is a bottom plan view of the sole structure of FIG. 11 ;

FIG. 17 is a cross-sectional view of the sole structure of FIG. 16 taken along line 17-17;

FIG. 17A is a cross-sectional view of the sole structure of FIG. 17 showing a rearward projection formed as a separate component;

FIG. 17B is a cross-sectional view of the sole structure of FIG. 17 showing a forward projection formed as a separate component;

FIG. 17C is a cross-sectional view of the sole structure of FIG. 17 showing a forward projection and a rearward projection formed as separate components;

FIG. 18 is a cross-sectional view of the sole structure of FIG. 16 , taken along line 18-18;

FIG. 19 is a cross-sectional view of the sole structure of FIG. 16 , taken along line 19-19;

FIG. 20 is a cross-sectional view of the sole structure of FIG. 16 , taken along line 20-20;

FIG. 21 is a side view of another configuration of an article of footwear in accordance with principles of the present disclosure;

FIG. 22 is an exploded top perspective view of the sole structure of FIG. 21 ;

FIG. 22A is an exploded top perspective view of the sole structure of FIG. 21 showing a rearward projection formed as a separate component;

FIG. 22B is an exploded top perspective view of the sole structure of FIG. 21 showing a forward projection formed as a separate component;

FIG. 22C is an exploded top perspective view of the sole structure of FIG. 21 showing a forward projection and a rearward projection formed as separate components;

FIG. 23 is an exploded bottom perspective view of the sole structure of FIG. 21 ;

FIG. 23A is an exploded bottom perspective view of the sole structure of FIG. 21 showing a rearward projection formed as a separate component;

FIG. 23B is an exploded bottom perspective view of the sole structure of FIG. 21 showing a forward projection formed as a separate component;

FIG. 23C is an exploded bottom perspective view of the sole structure of FIG. 21 showing a forward projection and a rearward projection formed as separate components;

FIG. 24 is a front view of the sole structure of FIG. 21 ;

FIG. 25 is a back view of the sole structure of FIG. 21 ;

FIG. 26 is a bottom plan view of the sole structure of FIG. 21 ;

FIG. 27 is a cross-sectional view of the sole structure of FIG. 26 , taken along line 27-27;

FIG. 27A is a cross-sectional view of the sole structure of FIG. 27 showing a rearward projection formed as a separate component;

FIG. 27B is a cross-sectional view of the sole structure of FIG. 27 showing a forward projection formed as a separate component;

FIG. 27C is a cross-sectional view of the sole structure of FIG. 27 showing a forward projection and a rearward projection formed as separate components;

FIG. 28 is a cross-sectional view of the sole structure of FIG. 26 , taken along line 28-28;

FIG. 29 is a cross-sectional view of the sole structure of FIG. 26 , taken along line 29-29; and

FIG. 30 is a cross-sectional view of the sole structure of FIG. 26 , taken along line 30-30.

Corresponding reference numerals indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.
The terminology used herein is for the purpose of describing particular exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
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.
In one configuration, a sole structure for an article of footwear includes a heel region, a forefoot region, and a fluid-filled chamber that extends from the heel region to the forefoot region. The sole structure further includes a midsole having a first projection contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection contacting the fluid-filled chamber at a second contact region in the heel region, the first projection being spaced apart and separated from the second projection.
The sole structure may additionally include one or more of the following optional features. Namely, the first projection may include a distal end defining a first engagement region in contact with the first contact region and the second projection may include a distal end defining a second engagement region in contact with the second contact region. The first engagement region and the second engagement region may be smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.
In one configuration, a gap is defined between the first projection and the second projection. The gap may extend from a medial side of the sole structure to a lateral side of the sole structure.
In one configuration, the midsole includes a substrate extending from the heel region to the forefoot region and includes a first surface and a second surface disposed on an opposite side of the substrate than the first surface. The first projection and the second projection extend from one of the first surface and the second surface.
The sole structure may include an outsole defining a ground-engaging surface, the outsole being attached to the second surface of the substrate. In another configuration, the sole structure may include a footbed operable to receive a foot of a wearer, the second surface of the substrate opposing the footbed.
In one configuration, the fluid-filled chamber may include a first end in contact with the midsole proximate to an anterior end of the sole structure. Additionally or alternatively, the fluid-filled chamber may include a second end spaced apart from the midsole proximate to a posterior end of the sole structure. A gap may extend from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.
In another configuration, a sole structure for an article of footwear includes a heel region, a forefoot region, and a fluid-filled chamber that extends from the heel region to the forefoot region. The sole structure further includes a midsole having a first projection extending from the midsole in a first direction and contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection extending from the midsole in a second direction opposite the first direction and contacting the fluid-filled chamber at a second contact region in the heel region.
The sole structure may include one or more of the following optional features. For example, the first projection may include a distal end defining a first engagement region in contact with the first contact region and the second projection may include a distal end defining a second engagement region in contact with the second contact region, the first engagement region and the second engagement region being smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.
In one configuration, the sole structure may include a gap defined between the first projection and the second projection, the gap extending from a medial side of the sole structure to a lateral side of the sole structure.
The midsole may include a first substrate extending from the forefoot region to the heel region and including a first surface and a second surface disposed on an opposite side of the first substrate than the first surface. The midsole may further include a second substrate extending from the heel region to a mid-foot region. The second substrate may include a third surface and a fourth surface disposed on an opposite side of the second substrate than the fourth surface. The first projection may extend from the second surface in a direction toward a ground-engaging surface of the sole structure and the second projection may extend from the third surface in a direction away from the ground-engaging surface.
The sole structure may further include an outsole defining the ground-engaging surface. The outsole may be attached to the fourth surface of the second substrate in the heel region and may be attached to the fluid-filled chamber in the forefoot region. The sole structure may further include a footbed operable to receive a foot of a wearer, the first surface of the first substrate opposing the footbed.
In one configuration, the fluid-filled chamber may include a first end in contact with the midsole proximate to an anterior end of the sole structure. Additionally or alternatively, the fluid-filled chamber may include a second end spaced apart from the midsole proximate to a posterior end of the sole structure. The sole structure may include a gap extending from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.
Referring to FIGS. 1, 11, and 21 , an article of footwear 10 includes an upper 100 and a sole structure 200, 300, 400. The article of footwear 10 may be divided into one or more regions. The regions may include a forefoot region 12, a mid-foot region 14, and a heel region 16. The forefoot region 12 may be subdivided into a toe portion 12 _Tcorresponding with phalanges, and a ball portion 12 _Bassociated with metatarsal bones of a foot. The mid-foot region 14 may correspond with an arch area of the foot, and the heel region 16 may correspond with rear portions of the foot, including a calcaneus bone.
The footwear 10 may further include an anterior end 18 associated with a forward-most point of the forefoot region 12, and a posterior end 20 corresponding to a rearward-most point of the heel region 16. A longitudinal axis A_F1of the footwear 10 extends along a length of the footwear 10 from the anterior end 18 to the posterior end 20, parallel to a ground surface. The longitudinal axis A_F1(shown in FIGS. 6, 16, 26 ) may be centrally located along the length of the footwear 10, such that the longitudinal axis A_F1generally divides the footwear 10 into a medial side 22 and a lateral side 24 (shown in FIGS. 6, 16, 26 ). Accordingly, the medial side 22 and the lateral side 24 respectively correspond with opposite sides of the footwear 10 and extend through the regions 12, 14, 16. As illustrated in FIGS. 6, 16, 26 , a lateral axis A_F2of the footwear 10 extends along a width of the footwear 10 from the medial side 22 to the lateral side 24, parallel to a ground surface, such that the lateral axis A_F2is disposed orthogonal to the longitudinal axis A_F1. As used herein, a longitudinal direction refers to the direction extending from the anterior end 18 to the posterior end 20, while a lateral direction refers to the direction transverse to the longitudinal direction and extending from the medial side 22 to the lateral side 24.
The article of footwear 10 and, more particularly, the sole structure 200, 300, 400, may be further described as including a peripheral region 26 and an interior region 28. The peripheral region 26 is generally described as being a region between the interior region 28 and an outer perimeter of the sole structure 200, 300, 400. Particularly, the peripheral region 26 extends from the forefoot region 12 to the heel region 16 along each of the medial side 22 and the lateral side 24, and wraps around each of the forefoot region 12 and the heel region 16. The interior region 28 is circumscribed by the peripheral region 26, and extends from the forefoot region 12 to the heel region 16 along a central portion of the sole structure 200, 300, 400. Accordingly, each of the forefoot region 12, the mid-foot region 14, and the heel region 16 may be described as including the peripheral region 26 and the interior region 28.
The upper 100 includes interior surfaces 101 that define an interior void 102 configured to receive and secure a foot for support on the sole structure 200, 300, 400. The upper 100 may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void 102. Suitable materials of the upper 100 may include, but are not limited to, mesh, 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.
In some examples, the upper 100 includes a strobel 104 having a bottom surface opposing the sole structure 200, 300, 400 and an opposing top surface defining a footbed 106 of the interior void 102. Stitching or adhesives may secure the strobel to the upper 100. The footbed 106 may be contoured to conform to a profile of the bottom surface (e.g., plantar) of the foot. Optionally, the upper 100 may also incorporate additional layers such as an insole or sockliner (not shown) that may be disposed upon the strobel 104. The insole or sockliner may reside within the interior void 102 of the upper 100 and be positioned to receive a plantar surface of the foot to enhance the comfort of the article of footwear 10. Referring again to FIGS. 1, 11, and 21 , an ankle opening 114 in the heel region 16 may provide access to the interior void 102. For example, the ankle opening 114 may receive a foot to secure the foot within the void 102 and to facilitate entry and removal of the foot from and to the interior void 102.
In some examples, one or more fasteners (not shown) extend along the upper 100 to adjust a fit of the interior void 102 around the foot and to accommodate entry and removal of the foot therefrom. The upper 100 may include apertures, such as eyelets and/or other engagement features such as fabric or mesh loops that receive the fasteners. The fasteners may include laces, straps, cords, hook-and-loop, or any other suitable type of fastener. The upper 100 may include a tongue portion (not shown) that extends between the interior void 102 and the fasteners.
The sole structure 200, 300, 400 includes a midsole 202, 302, 402 and a fluid-filled chamber 204 that cooperate with each other to provide cushioning characteristics to the sole structure 200, 300, 400, and an outsole 206 that provides a ground-engaging surface 30 of the article of footwear 10. The fluid-filled chamber 204 extends from the heel region 16 to the forefoot region 12 and has a length L_C(shown in FIGS. 7, 17, 27 ), which is shorter than a length L_Mof the midsole 202.
The midsole 202, 302, 402 provides zonal cushioning and performance characteristics and may include a substrate 208, 308, 408. The substrate 208, 308, 408 extends from the heel region 16 to the forefoot region 12 and includes a first surface 208 a, 308 a, 408 a and a second surface 208 b, 308 b, 408 b disposed on an opposite side of the substrate 208, 308, 408 than the first surface 208 a, 308 a, 408 a. The midsole 202, 302, 402 may further include a first projection 210, 310, 410 and a second projection 212, 312, 412 spaced apart from the first projection 210, 310, 410 to define a gap 214 therebetween. In one aspect, the first projection 210, 310, 410, the second projection 212, 312, 412, and the substrate 208, 308, 408 are formed as a unitary piece. In another aspect, the first projection 210, 310, 410 and/or the second projection 212, 312, 412 are formed as a separate component, as discussed in greater detail below.
The substrate 208, 308, 408 may be formed of a resilient polymeric material, such as foam or rubber, to impart properties of cushioning, responsiveness, and energy distribution to the foot of the wearer. The substrate 208, 308, 408 may independently be formed from a single unitary piece of resilient polymeric material, or may be formed of a plurality of elements each formed of one or more resilient polymeric materials. For example, the plurality of elements may be affixed to each other using a fusing process, using an adhesive, or by suspending the elements in a different resilient polymeric material.
Example resilient polymeric materials for the substrate 208, 308, 408 may include those based on foaming or molding one or more polymers, such as one or more elastomers (e.g., thermoplastic elastomers (TPE)). The one or more polymers may include aliphatic polymers, aromatic polymers, or mixtures of both; and may include homopolymers, copolymers (including terpolymers), or mixtures of both.
In some aspects, the one or more polymers may include olefinic homopolymers, olefinic copolymers, or blends thereof. Examples of olefinic polymers include polyethylene, polypropylene, and combinations thereof. In other aspects, the one or more polymers may include one or more ethylene copolymers, such as, ethylene-vinyl acetate (EVA) copolymers, EVOH copolymers, ethylene-ethyl acrylate copolymers, ethylene-unsaturated mono-fatty acid copolymers, and combinations thereof.
In further aspects, the one or more polymers may include one or more polyacrylates, such as polyacrylic acid, esters of polyacrylic acid, polyacrylonitrile, polyacrylic acetate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, and polyvinyl acetate; including derivatives thereof, copolymers thereof, and any combinations thereof.
In yet further aspects, the one or more polymers may include one or more ionomeric polymers. In these aspects, the ionomeric polymers may include polymers with carboxylic acid functional groups, sulfonic acid functional groups, salts thereof (e.g., sodium, magnesium, potassium, etc.), and/or anhydrides thereof. For instance, the ionomeric polymer(s) may include one or more fatty acid-modified ionomeric polymers, polystyrene sulfonate, ethylene-methacrylic acid copolymers, and combinations thereof.
In further aspects, the one or more polymers may include one or more styrenic block copolymers, such as acrylonitrile butadiene styrene block copolymers, styrene acrylonitrile block copolymers, styrene ethylene butylene styrene block copolymers, styrene ethylene butadiene styrene block copolymers, styrene ethylene propylene styrene block copolymers, styrene butadiene styrene block copolymers, and combinations thereof.
In further aspects, the one or more polymers may include one or more polyamide copolymers (e.g., polyamide-polyether copolymers) and/or one or more polyurethanes (e.g., crosslinked polyurethanes and/or thermoplastic polyurethanes). Examples of suitable polyurethanes include those for forming the fluid-filled chamber 204 as discussed below. Alternatively, the one or more polymers may include one or more natural and/or synthetic rubbers, such as butadiene and isoprene.
When the resilient polymeric material is a foamed polymeric material, the foamed material may be foamed using a physical blowing agent which phase transitions to a gas based on a change in temperature and/or pressure, or a chemical blowing agent which forms a gas when heated above its activation temperature. For example, the chemical blowing agent may be an azo compound such as adodicarbonamide, sodium bicarbonate, and/or an isocyanate.
In some embodiments, the foamed polymeric material may be a crosslinked foamed material. In these embodiments, a peroxide-based crosslinking agent such as dicumyl peroxide may be used. Furthermore, the foamed polymeric material may include one or more fillers such as pigments, modified or natural clays, modified or unmodified synthetic clays, talc glass fiber, powdered glass, modified or natural silica, calcium carbonate, mica, paper, wood chips, and the like.
The resilient polymeric material may be formed using a molding process. In one example, when the resilient polymeric material is a molded elastomer, the uncured elastomer (e.g., rubber) may be mixed in a Banbury mixer with an optional filler and a curing package such as a sulfur-based or peroxide-based curing package, calendared, formed into shape, placed in a mold, and vulcanized.
In another example, when the resilient polymeric material is a foamed material, the material may be foamed during a molding process, such as an injection molding process. A thermoplastic polymeric material may be melted in the barrel of an injection molding system and combined with a physical or chemical blowing agent and optionally a crosslinking agent, and then injected into a mold under conditions which activate the blowing agent, forming a molded foam.
Optionally, when the resilient polymeric material is a foamed material, the foamed material may be a compression molded foam. Compression molding may be used to alter the physical properties (e.g., density, stiffness and/or durometer) of a foam, or to alter the physical appearance of the foam (e.g., to fuse two or more pieces of foam, to shape the foam, etc.), or both.
The compression molding process desirably starts by forming one or more foam preforms, such as by injection molding and foaming a polymeric material, by forming foamed particles or beads, by cutting foamed sheet stock, and the like. The compression molded foam may then be made by placing the one or more preforms formed of foamed polymeric material(s) in a compression mold, and applying sufficient pressure to the one or more preforms to compress the one or more preforms in a closed mold. Once the mold is closed, sufficient heat and/or pressure is applied to the one or more preforms in the closed mold for a sufficient duration of time to alter the preform(s) by forming a skin on the outer surface of the compression molded foam, fuse individual foam particles to each other, permanently increase the density of the foam(s), or any combination thereof. Following the heating and/or application of pressure, the mold is opened and the molded foam article is removed from the mold.
As shown in the cross-sectional views of FIGS. 7-7C, 17-17C, 27-27C the fluid-filled chamber 204 may be formed by an opposing pair of barrier layers 216, which can be joined to each other along a peripheral seam 218 to define an interior chamber 220 forming an overall shape of the fluid-filled chamber 204. Alternatively, the fluid-filled chamber 204 can be produced from any suitable combination of one or more barrier layers 216. As used herein, the term “barrier layer” (e.g., barrier layers 216) encompasses both monolayer and multilayer films. In some embodiments, one or both of the barrier layers 216 are each produced (e.g., thermoformed or blow molded) from a monolayer film (a single layer). In other embodiments, one or both of the barrier layers 216 are each produced (e.g., thermoformed or blow molded) from a multilayer film (multiple sublayers). In either aspect, each layer or sublayer can have a film thickness ranging from about 0.2 micrometers to about 1 millimeter. In further embodiments, the film thickness for each layer or sublayer can range from about 0.5 micrometers to about 500 micrometers. In yet further embodiments, the film thickness for each layer or sublayer can range from about 1 micrometer to about 100 micrometers.
One or both of the barrier layers 216 can independently be transparent, translucent, and/or opaque. As used herein, the term “transparent” for a barrier layer and/or a bladder means that light passes through the barrier layer in substantially straight lines and a viewer can see through the barrier layer. In comparison, for an opaque barrier layer, light does not pass through the barrier layer and one cannot see clearly through the barrier layer at all. A translucent barrier layer falls between a transparent barrier layer and an opaque barrier layer, in that light passes through a translucent layer but some of the light is scattered so that a viewer cannot see clearly through the layer.
The barrier layers 216 can each be produced from an elastomeric material that includes one or more thermoplastic polymers and/or one or more cross-linkable polymers. In an aspect, the elastomeric material can include one or more thermoplastic elastomeric materials, such as one or more thermoplastic polyurethane (TPU) copolymers, one or more ethylene-vinyl alcohol (EVOH) copolymers, and the like.
As used herein, “polyurethane” refers to a copolymer (including oligomers) that contains a urethane group (—N(C═O)O—). These polyurethanes can contain additional groups such as ester, ether, urea, allophanate, biuret, carbodiimide, oxazolidinyl, isocynaurate, uretdione, carbonate, and the like, in addition to urethane groups. In an aspect, one or more of the polyurethanes can be produced by polymerizing one or more isocyanates with one or more polyols to produce copolymer chains having (—N(C═O)O—) linkages.
Examples of suitable isocyanates for producing the polyurethane copolymer chains include diisocyanates, such as aromatic diisocyanates, aliphatic diisocyanates, and combinations thereof. Examples of suitable aromatic diisocyanates include toluene diisocyanate (TDI), TDI adducts with trimethyloylpropane (TMP), methylene diphenyl diisocyanate (MDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), hydrogenated xylene diisocyanate (HXDI), naphthalene 1,5-diisocyanate (NDI), 1,5-tetrahydronaphthalene diisocyanate, para-phenylene diisocyanate (PPDI), 3,3′-dimethyldiphenyl-4,4′-diisocyanate (DDDI), 4,4′-dibenzyl diisocyanate (DBDI), 4-chloro-1,3-phenylene diisocyanate, and combinations thereof. In some embodiments, the copolymer chains are substantially free of aromatic groups.
In particular aspects, the polyurethane polymer chains are produced from diisocynates including HMDI, TDI, MDI, H12 aliphatics, and combinations thereof. In an aspect, the thermoplastic TPU can include polyester-based TPU, polyether-based TPU, polycaprolactone-based TPU, polycarbonate-based TPU, polysiloxane-based TPU, or combinations thereof.
In another aspect, the polymeric layer can be formed of one or more of the following: EVOH copolymers, poly(vinyl chloride), polyvinylidene polymers and copolymers (e.g., polyvinylidene chloride), polyamides (e.g., amorphous polyamides), amide-based copolymers, acrylonitrile polymers (e.g., acrylonitrile-methyl acrylate copolymers), polyethylene terephthalate, polyether imides, polyacrylic imides, and other polymeric materials known to have relatively low gas transmission rates. Blends of these materials, as well as with the TPU copolymers described herein and optionally including combinations of polyimides and crystalline polymers, are also suitable.
The barrier layers 216 may include two or more sublayers (multilayer film) such as shown in Mitchell et al., U.S. Pat. No. 5,713,141 and Mitchell et al., U.S. Pat. No. 5,952,065, the disclosures of which are incorporated by reference in their entireties. In embodiments where the barrier layers 216 include two or more sublayers, examples of suitable multilayer films include microlayer films, such as those disclosed in Bonk et al., U.S. Pat. No. 6,582,786, which is incorporated by reference in its entirety. In further embodiments, the barrier layers 216 may each independently include alternating sublayers of one or more TPU copolymer materials and one or more EVOH copolymer materials, where the total number of sublayers in each of the barrier layers 216 includes at least four (4) sublayers, at least ten (10) sublayers, at least twenty (20) sublayers, at least forty (40) sublayers, and/or at least sixty (60) sublayers.
The fluid-filled chamber 204 can be produced from the barrier layers 216 using any suitable technique, such as thermoforming (e.g. vacuum thermoforming), blow molding, extrusion, injection molding, vacuum molding, rotary molding, transfer molding, pressure forming, heat sealing, casting, low-pressure casting, spin casting, reaction injection molding, radio frequency (RF) welding, and the like. In an aspect, the barrier layers 216 can be produced by co-extrusion followed by vacuum thermoforming to form the profile of the fluid-filled chamber 204, which can optionally include one or more valves (not shown) that allows the fluid-filled chamber 204 to be filled with the fluid (e.g., gas).
The fluid-filled chamber 204 desirably have a low gas transmission rate to preserve its retained gas pressure. In some embodiments, the fluid-filled chamber 204 have a gas transmission rate for nitrogen gas that is at least about ten (10) times lower than a nitrogen gas transmission rate for a butyl rubber layer of substantially the same dimensions. In one aspect, fluid-filled chambers 106 a, 106 b have a nitrogen gas transmission rate of 15 cubic-centimeter/square-meter·atmosphere·day (cm³/m²·atm·day) or less for an average film thickness of 500 micrometers (based on thicknesses of barrier layers 216). In further aspects, the transmission rate is 10 cm³/m²·atm·day or less, 5 cm³/m²·atm·day or less, or 1 cm³/m²·atm·day or less.
In the shown embodiment, the barrier layers 216 include a first, upper barrier layer forming a top side 204 a of the fluid-filled chamber 204, and a second, lower barrier layer forming a bottom side 204 b of the fluid-filled chamber 204.
With reference now to FIGS. 1-10 , in one configuration, the midsole 202 is disposed between the upper 100 and the fluid-filled chamber 204 and the outsole 206 is attached to the bottom side 204 b of the fluid-filled chamber 204 on an opposite side of the fluid-filled chamber 204 than the midsole 202. The first projection 210 and the second projection 212 extend from the midsole 202 towards the outsole 206 and are in contact with the fluid-filled chamber 204. The fluid-filled chamber 204 has a generally constant thickness T_C, as shown in FIG. 7 . The anterior end 18 and the posterior end 20 of the fluid-filled chamber 204 are arcuate and extend in a direction toward the upper 100 and the portion of the fluid-filled chamber 204 located between the anterior end 18 and the posterior end 20 is generally planar. As shown in FIG. 7 , the second surface 208 b of the substrate 208 is spaced apart from the top side 204 a of the fluid filled chamber 204 and generally opposes the planar portion of the fluid-filled chamber 204.
With reference now to FIG. 2 , an exploded top perspective view of the sole structure 200 is provided. The first surface 208 a of the substrate 208 includes a lip portion 222 bounding the periphery of the substrate 208. The lip portion 222 includes an arcuate surface that defines a pocket 226 for accommodating the bottom of a foot. The lip portion 222 includes a seat portion 224 disposed on the anterior end 18 of the substrate 208. The seat portion 224 is an indent having a depth that is less than a thickness T_Oof the outsole 206 and receives a portion of the outsole 206.
With reference now to FIG. 3 , an exploded bottom perspective view of the sole structure 200 is provided. FIG. 3 depicts a configuration of the outsole 200 where the midsole 202 is formed as a unitary piece. In particular, the first projection 210 and the second projection 212 are molded to the second surface 208 b of the substrate 208 and extend from the second surface 208 b a distance defined by a thickness T_FPof the first projection 210 and a thickness T_SPthe second projection 212 (shown in FIG. 7 ). The first projection 210 may include a medial first projection 210 a disposed on the medial side 22 of the sole structure 200 and a lateral first projection 210 b disposed on the lateral side 24 of the sole structure 200. The medial first projection 210 a and the lateral first projection 210 b are spaced apart from each other in a direction across a width of the sole structure 200 (i.e., between the medial side 22 and the lateral side 24). A toe support 228 is formed on the second surface 208 b at the anterior end 18 of the midsole 202 forward of the projections 210 a, 210 b. The toe support 228 is spaced apart from the first projection 210 and includes a wall portion 230 that is generally disposed orthogonal to the second surface 208 b of the substrate 208. The wall portion 230 has a height H_Wthat is generally the same as the thickness T_Cof the fluid-filled chamber 204.
The second projection 212 is disposed on the second surface 208 b of the substrate 208 within the heel region 16 of the midsole 202. The medial first projection 210 a, the lateral first projection 210 b, and the second projection 212 are truncated pyramids such that each of the medial first projection 210 a, the lateral first projection 210 b, and the second projection 212 includes a substantially frustoconical shape. The medial first projection 210 a and the lateral first projection 210 b may be smaller than the second projection 212 and may extend between the medial side 22 and the lateral side 24 of the substrate 208. Likewise, the second projection 212 may extend between the medial side 22 and the lateral side 24 of the substrate 208 and is spaced apart from the medial first projection 210 a and the lateral first projection 210 b. The distal ends of the medial first projection 210 a, the lateral first projection 210 b, and the second projection 212 are illustratively shown as being planar and define a respective first engagement region 232 and second engagement region 234. The first engagement region 232 and the second engagement region 234 are configured to contact the fluid-filled chamber 204 at a respective first contact region 236 located in the forefoot region 12 of the fluid-filled chamber 204 and a second contact region 238 located in the heel region 16 of the fluid-filled chamber 204. The first engagement region 232 and the second engagement region 234 are smaller than a width We of the fluid-filled chamber 204, as shown in FIGS. 8 and 10 .
With reference now to FIGS. 4-7 and 8-10 , a depiction of the sole structure 200 in an assembled state is provided. With reference first to FIGS. 4 and 5 , the outsole 206 includes a toe portion 240 disposed on the anterior end 18 of the outsole 206. The toe portion 240 is generally arcuate, seats within the seat portion 224 of the substrate 208, and extends beyond the substrate 208. The fluid-filled chamber 204 is open to the environment such that compression of the fluid-filled chamber 204 by the first and second projections 210, 212 during use is readily visible.
With reference now to FIG. 7 , the midsole 202 is attached to the fluid-filled chamber 204 and the bottom side 204 b of the fluid-filled chamber 204 is attached to an interior surface 32 of the outsole 206. The second surface 208 b of the substrate 208 is spaced apart from the top side 204 a of the fluid filled chamber 204 between the first and second projections 210, 212. The first contact region 236 and the second contact region 238 of the fluid-filled chamber 204 are spaced apart from each other along the length of the fluid-filled chamber 204 and are disposed on the top side 204 a of the fluid-filled chamber 204. The first engagement region 232 and the second engagement region 234 are flush against the respective first contact region 236 and the second contact region 238 and may be attached thereto by a suitable adhesive. The wall portion 230 is generally arcuate and is attached to the anterior end of the fluid-filled chamber 204. The wall portion 230 is spaced apart from the posterior end 20 of the midsole 202 a distance generally commensurate with the length L_Cof the fluid-filled chamber 204.
In the configuration shown in FIGS. 1-10 , the first projection 210 and the second projection 212 are driven into the fluid-filled chamber 204 in a direction from the upper 100 to the outsole 206 to impart a load onto the fluid-filled chamber 204. In particular, the weight of the user drives the first engagement region 232 of the first projection 210 into the first contact region 236 and the second engagement region 234 of the second projection 212 into the second contact region 238 during use. Accordingly, the midsole 202 loads the fluid-filled chamber 204 at the first contact region 236 and the second contact region 238 of the top side 204 a of the fluid-filled chamber 204, wherein the remaining portion of the top side 204 a of the fluid-filled chamber 204 is spaced apart and free of the midsole 202. As such, the first projection 210 and the second projection 212 exert focused, point loads on the top side 204 s of the fluid-filled chamber 204. In so doing, the point loads effectively concentrate the forces from the wearer over relatively small areas of the fluid-filled chamber 204 and, as such, reduce the force required to deform the fluid-filled chamber 204 as compared to the same force applied over a larger surface area of the fluid-filled chamber 204.
With reference now to FIGS. 3A and 7A, in one configuration, the second projection 212 is formed separately from the midsole 202 a. In this configuration, the second surface 208 b of the substrate 208 includes the medial first projection 210 a and the lateral first projection 210 b integrally formed with the substrate 208 at the forefoot region 12, similar to the midsole 202 shown in FIG. 3 . However, the second surface 208 b of the substrate 208 at the heel region 16 is smooth and uninterrupted (i.e., free from an integrally formed projection).
As shown in FIG. 3A, the second projection 212 is a first bladder 242 and may be formed using the same material and methods as described above with respect to the fluid-filled chamber 204. Preferably, the first bladder 242 has a thickness T_B1commensurate with the thickness T_SPof the second projection 212 shown in FIG. 7 . In this configuration, the first bladder 242 is illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the first bladder 242 may be shaped as a truncated pyramid similar to what is shown in FIG. 3 . The first bladder 242 may be fixed to the second surface 208 b of the substrate 208 at the heel region 16 in generally the same location as the second projection 212 shown in FIG. 3 .
While the second surface 208 b of the substrate 208 is shown to be generally planar at the heel region 16, the second surface 208 b may include a recess at the heel region 16 that receives the first bladder 242. As shown, the first bladder 242 may include a first surface 242 a opposite a second surface 242 b, where the first surface 242 a and the second surface 242 b are both substantially planar. The first surface 242 a may be in contact with the second surface 208 b of the substrate 208 and may be attached thereto by a suitable adhesive. The second surface 242 b may define the second engagement region 234 and may be in contact with the second contact region 238 of the fluid-filled chamber 204.
With reference now to FIGS. 3B and 7B, in one configuration, the first projection 210 is formed separately from the midsole 202 b. In this configuration, the second surface 208 b of the substrate 208 includes the second projection 212 integrally formed with the substrate 208 at the heel region 16, similar to the midsole 202 shown in FIG. 3 . The second surface 208 b of the substrate 208 at the forefoot region 12 is generally planar. The first projection 210—including the medial first projection 210 a and the lateral first projection 210 b—includes a medial second bladder 244 a and a lateral second bladder 244 b. The medial second bladder 244 a and the lateral second bladder 244 b may be formed using the same material and methods as the fluid-filled chamber 204 described above. Preferably, the medial second bladder 244 a has a thickness T_MBcommensurate with the thickness T_SPof the medial first projection 210 a and the lateral second bladder 244 b has a thickness T_LBcommensurate with the thickness T_SPof the lateral first projection 210 b shown in FIG. 3 . The medial second bladder 244 a and the lateral second bladder 244 b are illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the medial second bladder 244 a and the lateral second bladder 244 b may be shaped as a truncated pyramid similar to the first projection 210 shown in FIG. 3 . The medial second bladder 244 a and the lateral second bladder 244 b may be fixed to the second surface 208 b of the substrate 208 at the forefoot region 12 in generally the same location as the medial first projection 210 a and the lateral first projection 210 b shown in FIG. 3 . A top surface of the medial second bladder 244 a and the lateral second bladder 244 b define the first engagement region 232 and engages the first contact region 238 disposed on the top side 204 a of the outsole 204.
With reference now to FIGS. 3C and 7C, the midsole 202 c, the first projection 210, and the second projection 212 are shown as being formed as separate components. In this configuration, the second surface 208 b of the substrate 208 is generally planar from the forefoot region 12 to the heel region 16. The second projection 212 is a first bladder 242 and the first projection 210 (i.e., the medial first projection 210 a and the lateral first projection 210 b) includes a medial second bladder 244 a and a lateral second bladder 244 b. The first bladder 242 is larger than each of the medial second bladder 244 a and the lateral second bladder 244 b. The first bladder 242, the medial second bladder 244 a, and the lateral second bladder 244 b are illustratively shown as being a truncated pyramid having a similar shape and size as the corresponding first projection 210 and second projection 212 described above with respect to FIG. 3 . The first bladder 242 is larger than the medial second bladder 244 a and the lateral second bladder 244 b and may be pressurized to the same or different pressure than at least one of the medial second bladder 244 a and the lateral second bladder 244 b. The medial second bladder 244 a and the lateral second bladder 244 b are shown as being generally the same size and may be pressurized to the same or different pressures. The medial second bladder 244 a and the lateral second bladder 244 b may be fixed to the second surface 208 b of the substrate 208 at the forefoot region 12 in generally the same location as the respective medial first projection 210 a and lateral first projection 210 b shown in FIG. 3 . Likewise, the first bladder 242 may be fixed to the second surface 208 b of the substrate 208 at the heel region 16 in generally the same location as the second projection 212 shown in FIG. 3 .
The first projection 210 and the second projection 212 shown in FIGS. 1-10 are configured to generate a load on the top side 204 a of the fluid-filled chamber 204 at the first contact region 236 and the second contact region 238. The first engagement region 232 of the first projection 210 and the second engagement region 234 of the second projection 212 contact the fluid-filled chamber 204 to space the second surface 208 b of the substrate 208 apart from the fluid-filled chamber 204. In so doing, the gap 214 separating the first projection 210 from the second projection 212 is defined and extends through the sole structure 200 from the medial side 22 to the lateral side 24. Accordingly, the sole structure 200 allows for the radial displacement of the midsole 200 about the first projection 210 and the second projection 212. Further, the sole structure 200 is relatively free to bend along a portion of the midsole 202, 202 a, 202 b, 202 c above the gap 214.
In the configuration of a sole structure 300 shown in FIGS. 11-20 , the outsole 206 and the fluid-filled chamber 204 are substantially the same as the outsole 206 and the fluid-filled chamber 204 shown in FIGS. 1-10 . The sole structure 300 includes a midsole 302 having a substrate 308 attached to the outsole 206, and is interposed between the outsole 206 and the fluid-filled chamber 204. The substrate 308 includes a first surface 308 a and a second surface 308 b formed on an opposite side of the substrate 308 than the first surface 308 a. The interior surface 32 of the outsole 204 is attached to the second surface 308 b of the substrate 308, as shown in FIG. 17 .
The midsole 302 includes a first projection 310 and a second projection 312 extending away from the outsole 206 towards the fluid-filled chamber 204 and in a direction towards the upper 100. As such, the fluid-filled chamber 204 is disposed above the substrate 308 of the midsole 302 and is in contact with the first projection 310 and the second projection 312. The first contact region 236 and the second contact region 238 are disposed on the bottom side 204 b of the fluid-filled chamber 204 rather than the top side 204 a, as described and shown in conjunction with the sole structure 200. The weight of the user drives the first contact region 236 and the second contact region 238 of the fluid-filled chamber 204 into engagement with the first engagement region 332 of the first projection 310 and the second engagement region 334 of the second projection 312. Accordingly, the midsole 302 loads the fluid-filled chamber 204 at the first contact region 236 and the second contact region 238 of the bottom side 204 b of the fluid-filled chamber 204, wherein the remaining portion of the bottom side 204 b of the fluid-filled chamber 204 is spaced apart and free of the midsole 302.
With reference now to FIGS. 12 and 13 , in one configuration of the sole structure 300, the first projection 310 and the second projection 312 are disposed on the first surface 308 a of the substrate 308. In this configuration, the first projection 310 and the second projection 312 are integrally formed with the substrate 308 to define a unitary structure. A toe support 328 is formed on the first surface 308 a at the anterior end 18 of the midsole 302. The toe support 328 is spaced apart from the first projection 310 and includes a wall portion 330 that is disposed generally orthogonal to the first surface 308 a of the substrate 308.
The sole structure 300 may include a bottom plate 348 having a rigidity that is greater than a rigidity of the substrate 308. In this configuration, the second surface 308 b of the substrate 308 may include a plate recess 350 having a depth and periphery that receives the bottom plate 348 in a flush manner such that a periphery of the plate recess 350 bounds a periphery of the bottom plate 348 and the outer surface of the bottom plate 348 is flush with the second surface 308 b of the substrate 308.
The sole structure 300 further includes a lip portion 322 and a pad 352 that are attached to the top side 204 a of the fluid-filled chamber 204. The lip portion 322 is a closed-loop band that bounds a periphery of the fluid-filled chamber 204 and is open at its center. The pad 352 is dimensioned to fill the open center of the lip portion 322 and has a thickness commensurate with a thickness of the interior of the lip portion 322 to form a flush, continuous surface, as shown in FIG. 19 . The lip portion 322 and the pad 352 form a pocket 326 for accommodating the bottom of a foot in a similar fashion as the pocket 226 described above. The lip portion 322 includes a seat portion 324 disposed on the anterior end 18 of the lip portion 322. The seat portion 324 is an indent having a depth that is less than a thickness T_Oof the outsole 206. The outsole 206 includes a toe portion 240 disposed on the anterior end 18 of the outsole 206. The toe portion 240 is generally arcuate and is seated within the seat portion 324 of the lip portion 322 and extends beyond an outer surface of the lip portion 322.
With reference now to FIGS. 14-17 and 18-20 , a depiction of the sole structure 300 in an assembled state is provided. In the assembled state, the fluid-filled chamber 204 is visible and open to the environment, such that compression of the fluid-filled chamber 204 by the first and second projections 210, 212 during use is readily visible.
With reference now to FIG. 17 , the first surface 308 a of the substrate 308 is shown as being spaced apart from the bottom side 204 b of the fluid filled chamber 204. The first contact region 236 and the second contact region 238 are spaced apart from each other along the length of the fluid-filled chamber 204 and are disposed on the bottom side 204 b of the fluid-filled chamber 204. The first engagement region 332 and the second engagement region 334 are flush against the respective first contact region 236 and the second contact region 238. The wall portion 330 is generally arcuate and receives the anterior end of the fluid-filled chamber 204 in a flush manner. The wall portion 330 is spaced apart from the posterior end 20 of the midsole 302 a distance generally commensurate with the length L_Cof the fluid-filled chamber 204.
In the configuration shown in FIGS. 11-20 , the fluid-filled chamber 204 is driven into the first projection 310 and the second projection 312 to impart a load on the fluid-filled chamber 204. In particular, the weight of a wearer drives the first contact region 236 of the fluid-filled chamber 204 into the first engagement region 332 of the first projection 310 and the second contact region 238 of the fluid-filled chamber 204 into the second engagement region 334 of the second projection 312. Accordingly, the midsole 302 loads the fluid-filled chamber 204 at the first contact region 236 and the second contact region 238 of the bottom side 204 b of the fluid-filled chamber 204, wherein the remaining portion of the bottom side 204 b of the fluid-filled chamber 204 is spaced apart and free of the midsole 302.
With reference now to FIGS. 12A and 17A, in one configuration of the midsole 302 a, the second projection 312 is formed as a separate component from the midsole 302 a. The first surface 308 a of the substrate 308 includes the first projection 310—including the medial first projection 310 a and the lateral first projection 310 b. In this configuration, the medial first projection 310 a and the lateral first projection 310 b are integrally formed with the substrate 308 at the forefoot region 12, similar to the midsole 302 shown in FIG. 12 . The first surface 208 a of the substrate 308 at the heel region 16 is generally smooth and uninterrupted. As shown, the second projection 312 is a first bladder 342 that is attached to the smooth surface of the substrate 308 at the heel region 16 by a suitable adhesive. The first bladder 342 may be formed using the same material and methods as described above with respect to the fluid-filled chamber 204. Preferably, the first bladder 342 has a thickness T_B1commensurate with the thickness T_SPof the second projection 312 shown in FIG. 12 . The first bladder 342 is illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the first bladder 342 may be shaped as a truncated pyramid similar to what is shown in FIG. 12 with respect to the second projection 312. The first bladder 342 may be fixed to the first surface 308 b of the substrate 308 at the heel region 16 in generally the same location as the second projection 312 shown in FIG. 12 .
It should be appreciated that although the first surface 308 a of the substrate 308 is shown to be generally planar at the heel region 16, the first surface 308 a may include a recess at the heel region 16 that receives the first bladder 342. The first bladder 342 includes a first planar surface 342 a opposite a second planar surface 342 b. The second surface 342 b is in contact with and may be attached to the first surface 308 a of the substrate 308 via a suitable adhesive and the first surface 342 a defines the second engagement region 334 and is in contact with and may be attached to the second contact region 238 of the outsole 206 by the same or different adhesive.
With reference now to FIGS. 12B and 17B, in one configuration of the midsole 302 b, the first projection 310 is formed as a separate component than the midsole 302 b. The first surface 308 a of the substrate 308 includes the second projection 212 integrally formed with the substrate 308 at the heel region 16, similar to the midsole 302 shown in FIG. 12 . The first surface 308 a of the substrate 308 at the forefoot region 12 is generally planar. The first projection 310 (i.e., the medial first projection 310 a and the lateral first projection 310 b) includes a medial second bladder 344 a and a lateral second bladder 344 b. The medial second bladder 344 a and the lateral second bladder 344 b may be formed using the same material and methods as the fluid-filled chamber 204 described above. Preferably, the medial second bladder 344 a has a thickness T_MBcommensurate with the thickness T_SPof the medial first projection 310 a and the lateral second bladder 344 b has a thickness T_LBcommensurate with the thickness T_SPof the lateral first projection 210 b shown in FIG. 12 . The medial second bladder 344 a and the lateral second bladder 344 b are illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the medial second bladder 344 a and the lateral second bladder 344 b may be shaped as a truncated pyramid similar to what is shown in FIG. 12 with respect to the medial first projection 310 a and the lateral first projection 310 b. The medial second bladder 344 a and the lateral second bladder 344 b may be fixed to the first surface 308 a of the substrate 308 at the forefoot region 12 by a suitable adhesive in generally the same location as the respective medial first projection 310 a and lateral first projection 310 b shown in FIG. 12 . The medial second bladder 344 a and the lateral second bladder 344 b may be fixed to the second surface 308 b of the substrate 308 at the forefoot region 12 in generally the same location as the respective medial first projection 310 a and lateral first projection 310 b shown in FIG. 12 . A top surface of the medial second bladder 344 a and the lateral second bladder 344 b define the first engagement region 332 and engage the first contact region 238 disposed on the bottom side 204 b of the outsole 204.
With reference now to FIGS. 12C and 17C, in one configuration of the midsole 302 c, the first projection 310 and the second projection 312 are formed as separate components from the midsole 302 c. The first surface 308 a of the substrate 308 is generally planar from the forefoot region 12 to the heel region 16. The second projection 312 is a first bladder 342 and the first projection 310—including the medial first projection 310 a and the lateral first projection 310 b—includes a medial second bladder 344 a and a lateral second bladder 344 b. The first bladder 342 is larger than each of the medial second bladder 344 a and the lateral second bladder 344 b. The first bladder 342, the medial second bladder 344 a, and the lateral second bladder 344 b are illustratively shown as being truncated pyramids in a similar fashion as the first projection 310 and the second projection 312 shown and described above with respect to FIG. 12 . The first bladder 342 is larger than the medial second bladder 344 a and the lateral second bladder 344 b and may include the same or different pressure than at least one of the medial second bladder 344 a and the lateral second bladder 344 b. The medial second bladder 344 a and the lateral second bladder 344 b are shown as being generally the same size and may include the same or different pressure than one another. The medial second bladder 344 a and the lateral second bladder 344 b may be fixed to the first surface 308 a of the substrate 308 by a suitable adhesive at the forefoot region 12 in generally the same location as the medial first projection 310 a and the lateral first projection 310 b, respectively. Likewise, the first bladder 342 may be fixed to the first surface 308 a of the substrate 308 by a suitable adhesive at the heel region 16 in generally the same location as the second projection 312 shown in FIG. 12 .
The sole structure 300 shown in FIGS. 11-20 is configured to generate a load on the bottom side 204 b of the fluid-filled chamber 204 at the first contact region 236 and the second contact region 238 by pressing the bottom side 204 b of the fluid-filled chamber 204 into the first projection 310 and the second projection 312. The first engagement region 232 of the first projection 210 and the second engagement region 234 of the second projection 212 contact the fluid-filled chamber 204 at discrete locations to space the first surface 308 a of the substrate 308 apart from the fluid-filled chamber 204. As such, the gap 214 that separates the first projection 310 from the second projection 312 likewise defines a void between the fluid-filled chamber 204 and the first surface 308 a of the substrate 308 that extends through the sole structure 300 from the medial side 22 to the lateral side 24. Accordingly, the sole structure 300 allows for the radial displacement of the midsole 302 about the first projection 310 and the second projection 312. Further, the sole structure 300 is relatively free to bend along a portion of the midsole 202 above the gap 214.
In the configuration of a sole structure 400 shown in FIGS. 21-30 , the outsole 206 is substantially the same as the outsole 206 shown in FIGS. 1-20 . The sole structure 400 includes a midsole 402 having a first substrate 408 and a second substrate 454 that is spaced apart and separate than the first substrate 408. The first substrate 408 includes a first surface 408 a and a second surface 408 b formed on an opposite side of the first substrate 408 than the first surface 408 a. The first surface 408 a defines a top of the substrate 408. The second substrate 454 includes a third surface 454 a and a fourth surface 454 b formed on an opposite side of the second substrate 454 than the third surface 454 a. The third surface 454 a defines the top of the second substrate 454 and the fourth surface 454 b defines the bottom of the second substrate 454. The first substrate 408 extends the length of the sole structure 400 from the forefoot region 12 to the heel region 16 and the second substrate 454 extends from the heel region 16 to the mid-foot region 14 of the sole structure 400.
The fluid-filled chamber 204 is disposed between the first substrate 408 and the second substrate 454. The fluid-filled chamber 204 includes a top side 204 a defining the top of the fluid-filled chamber 204 and a bottom side 204 b disposed on an opposite side of the fluid-filled chamber 204 than the top side 204 a. A first contact region 236 is disposed in the forefoot region 12 and on the top side 204 a of the fluid-filled chamber 204. A second contact region 238 is disposed in the heel region 16 and on the bottom side 204 b of the fluid-filled chamber 204 such that the contact regions 236, 238 are disposed on opposite sides of the fluid-filled chamber 204.
With reference now to FIG. 27 , the fluid-filled chamber 204 includes a forefoot portion 205, a mid-foot portion 207, and a heel portion 209. The mid-foot portion 207 connects the forefoot portion 205 to the heel portion 209. The heel portion 209 is elevated relative to the forefoot portion 205 and, as such, causes the mid-foot portion 207 to be angled relative to the forefoot portion 205 and the heel portion 209. In this manner, the mid-foot portion 207 acts as a transition between the forefoot portion 205 and the elevated heel portion 209 and defines an arcuate segment of the fluid-filled chamber 204, as shown in FIG. 27 .
The midsole 302 further includes a first projection 410 and a second projection 412. The first projection 410 may be disposed on the first substrate 408, extends in a first direction, and contacts the fluid filled chamber 204 at a first contact region 236. The second projection 412 may be disposed on the second substrate 454 and extends in a second direction opposite the first direction and contacts the fluid filled chamber 204 at a second contact region 238.
In one configuration, the first projection 410 includes a medial first projection 410 a and a lateral first projection 410 b. The medial first projection 410 a, the lateral first projection 410 b, and the second projection 412 are truncated pyramids having a frustoconical shape that are integrally formed with the respective first substrate 408 and second substrate 454.
The medial first projection 410 a and the lateral first projection 410 b are generally the same dimension as each other and are smaller in dimension than the second projection 412. The first projection 410 extends from the second surface 408 b of the first substrate 408 in a direction toward the ground-engaging surface 30 of the sole structure 400 and the second projection extends from the third surface 454 a of the second substrate 454 in a direction away from the ground-engaging surface 30. A distal end of the first projection 410 defines a first engagement region 432 and a distal end of the second projection 412 defines a second engagement region 434. The first engagement region 432 engages the first contact region 236 of the outsole 206 and the second engagement region 434 engages the second contact region 238 of the outsole 206. As shown in FIGS. 28 and 30 , the first engagement region 432 and the second engagement region 434 are smaller than a width We of the fluid-filled chamber 204 defined between the medial side 22 of the fluid-filled chamber 204 and the lateral side 24 of the fluid-filled chamber 204.
As shown in FIGS. 21 and 27-30 , the first surface 408 a of the substrate 408 opposes the footbed 106. The outsole 206 is attached to the fourth surface 454 b of the second substrate 454 in the heel region 16 and is attached to the bottom side 204 b of the forefoot portion 205 of fluid-filled chamber 204 in the forefoot region 12 of the sole structure 400. In the heel region 16 of the sole structure 400, the heel portion 209 of the fluid-filled chamber 204 is disposed between the second substrate 454 and the first substrate 408. In the mid-foot region 14 of the sole structure 400, the fluid-filled chamber 204 is disposed with a gap 214 extending between the medial side 22 and the lateral side 24 of the sole structure 400 and between the first projection 410 and the second projection 412. In the mid-foot region 14 of the sole structure 400, the fluid-filled chamber 400 is also disposed between the first substrate 408 and the second substrate 454. In the fore-foot region 12, the fluid-filled chamber 204 is disposed between the outsole 206 and the first substrate 408.
With reference now to FIG. 23 , a toe support 428 is formed on the second surface 408 b at the anterior end 18 of the first substrate 408. The toe support 428 is spaced apart from the first projection 410 and includes a wall portion 430 that is generally orthogonal to the second surface 408 b of the substrate 408. The wall portion 430 has a height H_Wthat is generally the same as the thickness T_Cof the fluid-filled chamber 204.
The sole structure 400 may include a bottom plate 448. The bottom plate 448 may have a rigidity that is greater than a rigidity of the second substrate 454. The fourth surface 454 b of the second substrate 454 may include a plate recess 450 having a depth and periphery that receives the bottom plate 448 in a flush manner such that the periphery of the plate recess 450 bounds a periphery of the bottom plate 448 and the outer surface of the bottom plate 448 is flush with the fourth surface 454 b of the second substrate 454.
The sole structure 400 may further include a top plate 456. The top plate 456 may be formed from the same or different material as the bottom plate 448 and may have a similar rigidity as the bottom plate 448. The first surface 408 a of the first substrate 408 may include a top plate recess 458 having a depth and periphery that receives the top plate 456 in a flush manner such that the periphery of the top plate recess 458 bounds a periphery of the top plate 456 and the top surface of the top plate 456 is flush with the first surface 408 a of the first substrate 408.
The sole structure 400 may further include a lip portion 422 bounding the periphery of the first substrate 408. The lip portion 422 may include an arcuate surface that defines a pocket 426 for accommodating the bottom of a foot in a similar fashion as the pocket 226 described above. The lip portion 422 includes a seat portion 424 disposed on the anterior end 18 of the first substrate 408. The seat portion 424 is an indent having a depth that is less than a thickness T_Oof the outsole 206. The outsole 206 includes a toe portion 240 disposed on the anterior end 18 of the outsole 206. The toe portion 240 is generally arcuate, is seated within the seat portion 224 of the substrate 208, and extends beyond the substrate 208.
With reference now to FIGS. 14-17 and 18-20 , a depiction of the sole structure 300 in an assembled state is provided. The fluid-filled chamber 204 is visible and open to the environment, such that compression of the fluid-filled chamber 204 by the first and second projections 210, 212 is readily visible.
With reference now to FIG. 27 , the second surface 408 b of the substrate 408 is in contact with the top side 204 a of the fluid filled chamber 204 at the heel region 205 of the fluid-filled chamber 204. The first contact region 236 and the second contact region 238 are spaced apart from each other along the length of the fluid-filled chamber 204. The first contact region 236 is disposed on the top side 204 a of the fluid-filled chamber 204 and the second contact region 238 is disposed on the bottom side 204 b of the fluid-filled chamber 204. The first engagement region 332 and the second engagement region 333 are flush against the respective first contact region 236 and the second contact region 238 and may be attached thereto by a suitable adhesive. The wall portion 430 is generally arcuate and receives the anterior end of the fluid-filled chamber 204 in a flush manner. The wall portion 430 is spaced apart from the posterior end 20 of the midsole 402 a distance generally commensurate with the length L_Cof the fluid-filled chamber 204. Accordingly, an anterior end (i.e., a first end) of the fluid-filled chamber 204 is in contact with the midsole 402 proximate to the anterior end 18 of the sole structure 400 and a posterior end (i.e., a second send) of the fluid-filled chamber 204 is spaced apart from the second substrate 454 of the midsole 402 proximate to the posterior 20 of the sole structure 400.
With reference now to FIGS. 22A, 23A and 27A, in one configuration of the midsole 402 a, the second projection 412 is formed as a separate component from the second substrate 454. The second surface 408 b of the first substrate 408 includes the medial first projection 410 a and the lateral first projection 410 b. The medial first projection 410 a and the lateral first projection 410 b are integrally formed therewith at the forefoot region 12, similar to the first substrate 408 shown in FIG. 23 . The second surface 408 b of the first substrate 408 at the heel region 16 is smooth and uninterrupted. The second projection 412 is a first bladder 442 that may be formed using the same material and methods as the fluid-filled chamber 204 described above. Preferably, the first bladder 442 has a thickness T_B1commensurate with the thickness T_SPof the second projection 412 shown in FIG. 22 . The first bladder 442 is illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the first bladder 442 may be shaped as a truncated pyramid similar to the second projection 412 shown in FIG. 22 . The first bladder 442 may be fixed to the third surface 454 a of the second substrate 454 at the heel region 16 in generally the same location as the second projection 412 shown in FIG. 22 .
It should be appreciated that although the third surface 454 a of the second substrate 454 is shown to be generally planar at the heel region 16, the third surface 454 a may include a recess at the heel region 16 that receives the first bladder 442. The first bladder 442 includes a first surface 442 a opposite a second surface 442 b. The first surface 442 a and the second surface 442 b are illustratively shown as being planar surfaces. The second surface 442 b is in contact with the third surface 454 a of the second substrate 454 and may be fixed thereto and the first surface 442 a defines the second engagement region 434 and is in contact with the second contact region 238 of the outsole 206.
With reference now to FIGS. 22B, 23B and 27B, in one configuration of the midsole 402 b, the first projection 410 is formed as a separate component. The first surface 454 a of the second substrate 454 includes the second projection 412 integrally formed with the second substrate 454 at the heel region 16, similar to the second substrate 454 shown in FIG. 22 . The second surface 408 b of the first substrate 408 is continuous from the anterior end 18 to the posterior end 20. The first projection 410 (i.e., the medial first projection 410 a and the lateral first projection 410 b) includes a medial second bladder 444 a and a lateral second bladder 444 b. The medial second bladder 444 a and the lateral second bladder 444 b may be formed using the same material and methods as the fluid-filled chamber 204 described above. Preferably, the medial second bladder 444 a has a thickness T_MBcommensurate with the thickness T_SPof the medial first projection 410 a and the lateral second bladder 444 b has a thickness T_LBcommensurate with the thickness T_SPof the lateral first projection 210 b shown in FIG. 23 . The medial second bladder 444 a and the lateral second bladder 444 b are illustratively shown as being cuboidal with rounded edges. However, it should be appreciated that the medial second bladder 444 a and the lateral second bladder 444 b may be shaped as a truncated pyramid similar to what is shown in FIG. 23 with respect to the medial first projection 410 a and the lateral first projection 410 b. The medial second bladder 444 a and the lateral second bladder 444 b may be fixed to the second surface 408 b of the first substrate 408 at the forefoot region 12 in generally the same location as the medial first projection 410 a and the lateral first projection 410 b, respectively.
With reference now to FIGS. 22C, 23C, and 27C, in one configuration of the midsole 402 c, the first projection 410 and the second projection 412 are formed as separate components than the midsole 402 c. The second surface 408 b of the first substrate 408 is generally smooth and uninterrupted from the anterior end 18 to the posterior end 20. Likewise, the first surface 454 a of the second substrate 454 is generally smooth and uninterrupted from the anterior end 18 to the posterior end 20. The second projection 412 is a first bladder 442 and the first projection 410 (i.e., the medial first projection 410 a and the lateral first projection 410 b) includes a medial second bladder 444 a and a lateral second bladder 444 b. The first bladder 442 is larger than each of the medial second bladder 444 a and the lateral second bladder 444 b and may include the same or different pressure. The medial second bladder 344 a and the lateral second bladder 344 b are shown as being generally the same size and may include the same or different pressure than one another. The first bladder 442, the medial second bladder 444 a, and the lateral second bladder 444 b are illustratively shown as being a truncated pyramid. The medial second bladder 444 a and the lateral second bladder 444 b may be fixed to the second surface 408 b of the first substrate 408 at the forefoot region 12 in generally the same location as the medial first projection 410 a and the lateral first projection 410 b shown in FIG. 23 . The first bladder 442 may be fixed to the first surface 454 a of the second substrate 454 at the heel region 16 in generally the same location as the second projection 412 shown in FIG. 22 .
The sole structure 400 shown in FIGS. 21-30 is configured to generate a load on the top side 204 a and the bottom side 204 b of the fluid-filled chamber 204. At the heel region 16, the load is applied to the first contact region 236 located on the bottom side 204 b of the fluid-filled chamber 204. At the forefoot region 12, the load is applied to the first contact region 236 located on the top side 204 b of the fluid-filled chamber 204. The first engagement region 432 of the first projection 410 is disposed above the first contact region 236 and the second engagement region 434 of the second projection 412 is disposed beneath the second contact region 238.
The first projection 410 extends from the first substrate 408 towards the outsole 206 and contacts the first contact region 236 of the fluid-filled chamber 204 and the bottom side 204 b of the fluid-filled chamber 204 is mounted onto the interior surface 32 of the outsole 206. The second surface 408 b of the first substrate 408 surrounding the first projection 410 is spaced apart from the top side 204 a of the fluid-filled chamber 204.
The second projection 412 extends from the second substrate 454 towards the upper 100 and contacts the second contact region 238 of the fluid-filled chamber 204. The top side 204 a of the fluid-filled chamber 204 contacts the second surface 408 b of the substrate 408, and the third surface 454 a of the second substrate 454 surrounding the second projection 412 is spaced apart from the bottom side 204 b of the outsole 206. The gap 214 separates the first projection 410 from the second projection 412, and the outsole 206 extends through the gap 214 at an angle. Accordingly, the sole structure 400 allows for the radial displacement of the midsole 400 about the first projection 410 and the second projection 412. Further, the sole structure 400 is relatively free to bend along a portion of the midsole 402 above the gap 214.
The following Clauses provide exemplary configurations for the sole structure and article of footwear described above.

- Clause 1. A sole structure for an article of footwear includes a heel region, a forefoot region, a fluid-filled chamber and a midsole. The fluid-filled chamber extends from the heel region to the forefoot region. The midsole includes a first projection contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection contacting the fluid-filled chamber at a second contact region in the heel region. The first projection is spaced apart and separated from the second projection.
- Clause 2. The sole structure of Clause 1, wherein the first projection includes a distal end defining a first engagement region in contact with the first contact region and the second projection includes a distal end defining a second engagement region in contact with the second contact region, the first engagement region and the second engagement region being smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.
- Clause 3. The sole structure of any of the preceding Clauses, wherein a gap is defined between the first projection and the second projection, the gap extending from a medial side of the sole structure to a lateral side of the sole structure.
- Clause 4. The sole structure of any of the preceding Clauses, wherein the midsole includes a substrate extending from the heel region to the forefoot region and including a first surface and a second surface disposed on an opposite side of the substrate than the first surface, the first projection and the second projection extending from one of the first surface and the second surface.
- Clause 5. The sole structure of Clause 4, further comprising an outsole defining a ground-engaging surface, the outsole attached to the second surface of the substrate.
- Clause 6. The sole structure of Clause 4, further comprising a footbed operable to receive a foot of a wearer, the second surface of the substrate opposing the footbed.
- Clause 7. The sole structure of any of the preceding Clauses, wherein the fluid-filled chamber includes a first end in contact with the midsole proximate to an anterior end of the sole structure.
- Clause 8. The sole structure of any of the preceding Clauses, wherein the fluid-filled chamber includes a second end spaced apart from the midsole proximate to a posterior end of the sole structure.
- Clause 9. The sole structure of any of the preceding Clauses, further comprising a gap extending from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.
- Clause 10. An article of footwear incorporating the sole structure of any of the preceding Clauses.
- Clause 11. A sole structure for an article of footwear includes a heel region, a forefoot region, a fluid-filled chamber and a midsole. The fluid-filled chamber extends from the heel region to the forefoot region. The midsole includes a first projection extending from the midsole in a first direction and contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection extending from the midsole in a second direction opposite the first direction and contacting the fluid-filled chamber at a second contact region in the heel region.
- Clause 12. The sole structure of Clause 11, wherein the first projection includes a distal end defining a first engagement region in contact with the first contact region and the second projection includes a distal end defining a second engagement region in contact with the second contact region, the first engagement region and the second engagement region being smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.
- Clause 13. The sole structure of any of the preceding Clauses, wherein a gap is defined between the first projection and the second projection, the gap extending from a medial side of the sole structure to a lateral side of the sole structure.
- Clause 14. The sole structure of any of the preceding Clauses, wherein the midsole includes a first substrate extending from the forefoot region to the heel region and including a first surface and a second surface disposed on an opposite side of the first substrate than the first surface and a second substrate extending from the heel region to a mid-foot region and including a third surface and a fourth surface disposed on an opposite side of the second substrate than the fourth surface, the first projection extending from the second surface in a direction toward a ground-engaging surface of the sole structure and the second projection extending from the third surface in a direction away from the ground-engaging surface.
- Clause 15. The sole structure of Clause 14, further comprising an outsole defining the ground-engaging surface, the outsole attached to the fourth surface of the second substrate in the heel region and attached to the fluid-filled chamber in the forefoot region.
- Clause 16. The sole structure of Clause 14, further comprising a footbed operable to receive a foot of a wearer, the first surface of the first substrate opposing the footbed.
- Clause 17. The sole structure of any of the preceding Clauses, wherein the fluid-filled chamber includes a first end in contact with the midsole proximate to an anterior end of the sole structure.
- Clause 18. The sole structure of any of the preceding Clauses, wherein the fluid-filled chamber includes a second end spaced apart from the midsole proximate to a posterior end of the sole structure.
- Clause 19. The sole structure of any of the preceding Clauses, further comprising a gap extending from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.
- Clause 20. An article of footwear incorporating the sole structure of any of Clauses 11-19.

The foregoing description has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but, where applicable, are interchangeable and can be used in a selected configuration, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

What is claimed is:

1. A sole structure for an article of footwear, the sole structure comprising:

a heel region;

a forefoot region;

a fluid-filled chamber extending from the heel region to the forefoot region; and

a midsole including a first projection contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection contacting the fluid-filled chamber at a second contact region in the heel region, the first projection being spaced apart and separated from the second projection.

2. The sole structure of claim 1, wherein the first projection includes a distal end defining a first engagement region in contact with the first contact region and the second projection includes a distal end defining a second engagement region in contact with the second contact region, the first engagement region and the second engagement region being smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.

3. The sole structure of claim 1, wherein a gap is defined between the first projection and the second projection, the gap extending from a medial side of the sole structure to a lateral side of the sole structure.

4. The sole structure of claim 1, wherein the midsole includes a substrate extending from the heel region to the forefoot region and including a first surface and a second surface disposed on an opposite side of the substrate than the first surface, the first projection and the second projection extending from one of the first surface and the second surface.

5. The sole structure of claim 4, further comprising an outsole defining a ground-engaging surface, the outsole attached to the second surface of the substrate.

6. The sole structure of claim 4, further comprising a footbed operable to receive a foot of a wearer, the second surface of the substrate opposing the footbed.

7. The sole structure of claim 1, wherein the fluid-filled chamber includes a first end in contact with the midsole proximate to an anterior end of the sole structure.

8. The sole structure of claim 1, wherein the fluid-filled chamber includes a second end spaced apart from the midsole proximate to a posterior end of the sole structure.

9. The sole structure of claim 1, further comprising a gap extending from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.

10. An article of footwear incorporating the sole structure of claim 1.

11. A sole structure for an article of footwear, the sole structure comprising:

a heel region;

a forefoot region;

a midsole including a first projection extending from the midsole in a first direction and contacting the fluid-filled chamber at a first contact region in the forefoot region and a second projection extending from the midsole in a second direction opposite the first direction and contacting the fluid-filled chamber at a second contact region in the heel region.

12. The sole structure of claim 11, wherein the first projection includes a distal end defining a first engagement region in contact with the first contact region and the second projection includes a distal end defining a second engagement region in contact with the second contact region, the first engagement region and the second engagement region being smaller than a width of the fluid-filled chamber defined between a medial side of the fluid-filled chamber and a lateral side of the fluid-filled chamber.

13. The sole structure of claim 11, wherein a gap is defined between the first projection and the second projection, the gap extending from a medial side of the sole structure to a lateral side of the sole structure.

14. The sole structure of claim 11, wherein the midsole includes a first substrate extending from the forefoot region to the heel region and including a first surface and a second surface disposed on an opposite side of the first substrate than the first surface and a second substrate extending from the heel region to a mid-foot region and including a third surface and a fourth surface disposed on an opposite side of the second substrate than the fourth surface, the first projection extending from the second surface in a direction toward a ground-engaging surface of the sole structure and the second projection extending from the third surface in a direction away from the ground-engaging surface.

15. The sole structure of claim 14, further comprising an outsole defining the ground-engaging surface, the outsole attached to the fourth surface of the second substrate in the heel region and attached to the fluid-filled chamber in the forefoot region.

16. The sole structure of claim 14, further comprising a footbed operable to receive a foot of a wearer, the first surface of the first substrate opposing the footbed.

17. The sole structure of claim 11, wherein the fluid-filled chamber includes a first end in contact with the midsole proximate to an anterior end of the sole structure.

18. The sole structure of claim 11, wherein the fluid-filled chamber includes a second end spaced apart from the midsole proximate to a posterior end of the sole structure.

19. The sole structure of claim 11, further comprising a gap extending from a medial side of the sole structure to a lateral side of the sole structure between the first projection and an anterior end of the sole structure.

20. An article of footwear incorporating the sole structure of claim 11.