Patent Description:
This section provides background information related to the claimed invention which is not necessarily prior art.

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 increase durability of the sole structure, as well as 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 a 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 bladder formed from two barrier layers of polymer material that are sealed or bonded together. The fluid-filled bladders are pressurized with a fluid such as air, and may incorporate tensile members within the bladder to retain the shape of the bladder when compressed resiliently under applied loads, such as during athletic movements. Generally, bladders are designed with an emphasis on balancing support for the foot and cushioning characteristics that relate to responsiveness as the bladder resiliently compresses under an applied load. <CIT> describes that a sole structure includes a midsole layer with a lower surface having a first recess that has an outer periphery spaced inward of an outer periphery of the midsole layer, and a peripheral bonding region between the outer periphery of the midsole layer and the outer periphery of the first recess. <CIT> describes a footwear sole structure having a fluid-filled chamber including a tensile member. The fluid-filled chamber includes a first barrier sheet, a second barrier sheet and the tensile member. The first barrier sheet is formed from a first thermoplastic material. The second barrier sheet is attached to the first barrier sheet and is formed from a second thermoplastic material. The first barrier sheet and the second barrier sheet cooperate to define an internal cavity. The tensile member is disposed within the internal cavity and is formed from a third thermoplastic material.

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

Example configurations are provided so that the claimed invention will be thorough, and will fully convey the scope of the claimed invention 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 claimed invention. 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 claimed invention.

The claimed invention is defined in claims <NUM>, <NUM> and <NUM>.

Implementations of the claimed invention may include one or more of the following optional features. The arcs may be in fluid communication with the perimeter region and the central region. In another aspect, the arcs may be concentric with one another.

The perimeter region surrounds the central region and the two arcs. In one aspect, the perimeter region may be in fluid communication with the central region. The interior void may be pressurized.

In some configurations, the perimeter region includes a pair of medial lobes and a pair of lateral lobes. In one aspect, one of the pair of medial lobes has a thickness that may be greater than a thickness of the other of the pair of medial lobes and one of the pair of lateral lobes has a thickness may be greater than a thickness of the other of the pair of lateral lobes. An article of footwear may incorporate the fluid-filled chamber.

In another aspect of the disclosure, a bladder assembly is provided. The bladder assembly includes a first fluid-filled chamber and a second fluid-filled chamber. The first fluid-filled chamber includes a first barrier layer and a second barrier layer. The first barrier layer and the second barrier layer cooperate with each other to define an interior void that is asymmetric about a longitudinal axis of the fluid-filled chamber.

The interior void including a first thickness measured in a first direction between the first barrier layer and the second barrier layer at a perimeter region of the interior void and a second thickness measured in the first direction that is less than the first thickness at a central region of the interior void. The first fluid-filled chamber further includes a tensile member disposed within the interior void and received within the central region. The second fluid-filled chamber includes a first barrier layer and a second barrier layer cooperating with the first barrier layer to define an interior void. The interior void includes a perimeter region bounding a web area. The web area bounds a central region.

In one implementation, the first fluid-filled chamber further includes at least two arcs disposed between the perimeter region and the central region of the first fluid-filled chamber. The at least two arcs may be in fluid communication with the perimeter region and the central region of the first fluid-filled chamber. In another aspect, the at least two arcs are concentric with one another.

In one implementation, the perimeter region of the first fluid-filled chamber surrounds the central region and the at least two arcs.

In one implementation the second fluid-filled chamber further includes a pair of medial lobes, a pair of lateral lobes and a posterior lobe fluidly connecting the pair of medial lobes to the pair of lateral lobes.

In one implementation, one of the pair of medial lobes of the second fluid-filled chamber is longer than the other of the pair of medial lobes of the second fluid-filled chamber, and one of the pair of lateral lobes of the second fluid-filled chamber is longer than the other of the pair of lateral lobes of the second fluid-filled chamber.

In one implementation, the pair of lateral lobes of the second fluid-filled chamber extends towards the first fluid-filled chamber to a greater extent than the pair of medial lobes.

In one implementation, the interior void of the first fluid-filled chamber and the second fluid-filled chamber is pressurized. An article of footwear may incorporate the bladder assembly.

Referring to <FIG>, an article of footwear <NUM> includes a sole structure <NUM> and an upper <NUM> attached to the sole structure <NUM>. The article of footwear <NUM> may be divided into one or more regions. The regions may include a forefoot region <NUM>, a mid-foot region <NUM>, and a heel region <NUM>. The forefoot region <NUM> may be further described as including a toe portion <NUM>T corresponding to the phalanges of the foot, and a ball portion <NUM>B corresponding to a metatarsophalangeal (MTP) joint. The mid-foot region <NUM> may correspond with an arch area of the foot, and the heel region <NUM> may correspond with rear portions of the foot, including a calcaneus bone. The footwear <NUM> may further include an anterior end <NUM> associated with a forward-most point of the forefoot region <NUM>, and a posterior end <NUM> corresponding to a rearward-most point of the heel region <NUM>. A longitudinal axis A<NUM> of the footwear <NUM> extends along a length of the footwear <NUM> from the anterior end <NUM> to the posterior end <NUM>, and generally divides the footwear <NUM> into a medial side <NUM> and a lateral side <NUM>, as shown in <FIG>. Accordingly, the medial side <NUM> and the lateral side <NUM> respectively correspond with opposite sides of the footwear <NUM> and extend through the regions <NUM>, <NUM>, <NUM>.

The article of footwear <NUM>, and more particularly, the sole structure <NUM>, may be further described as including an interior region <NUM> and a peripheral region <NUM>, as indicated in <FIG>. The peripheral region <NUM> is generally described as being a region between the interior region <NUM> and an outer perimeter of the sole structure <NUM>. Particularly, the peripheral region <NUM> extends from the forefoot region <NUM> to the heel region <NUM> along each of the medial side <NUM> and the lateral side <NUM>, and wraps around each of the forefoot region <NUM> and the heel region <NUM>. Thus, the interior region <NUM> is circumscribed by the peripheral region <NUM>, and extends from the forefoot region <NUM> to the heel region <NUM> along a central portion of the sole structure <NUM>.

With reference to <FIG> and <FIG>, the sole structure <NUM> includes a midsole <NUM> configured to provide cushioning characteristics to the sole structure <NUM>, and an outsole <NUM> configured to provide a ground-engaging surface of the article of footwear <NUM>. Unlike conventional sole structures, the midsole <NUM> of the sole structure <NUM> may be formed compositely and include a plurality of subcomponents for providing desired forms of cushioning and support throughout the sole structure <NUM>. For example, the midsole <NUM> includes a bladder assembly <NUM> and a chassis <NUM>, where the chassis <NUM> is attached to the upper <NUM> and provides an interface between the upper <NUM> and the bladder assembly <NUM>. The bladder assembly <NUM> may include a first fluid-filled chamber 106a and a second fluid-filled chamber 106b. The first fluid-filled chamber 106a is a separate structure from the second fluid-filled chamber 106b and is spaced apart from the second fluid-filled chamber 106b when assembled as midsole <NUM>.

A longitudinal axis A<NUM> of the bladder assembly <NUM> extends from a first end <NUM> in the forefoot region <NUM> to a second end <NUM> in the heel region <NUM>. The bladder assembly <NUM> may be further described as including a top surface or side <NUM> and a bottom surface or side <NUM> formed on an opposite side of the bladder assembly <NUM> from the top side <NUM>. As discussed in greater detail below with respect to <FIG>, a thicknesses T<NUM> of the bladder assembly <NUM>, or of elements of the bladder assembly <NUM>, are defined by a distance from the top side <NUM> to the bottom side <NUM>.

As shown in the cross-sectional view of <FIG>, the bladder assembly <NUM> may be formed by an opposing pair of barrier layers <NUM>, which can be joined to each other at discrete locations to define an overall shape of the bladder assembly <NUM>. Alternatively, the bladder assembly <NUM> can be produced from any suitable combination of one or more barrier layers <NUM>. As used herein, the term "barrier layer" (e.g., barrier layers <NUM>) encompasses both monolayer and multilayer films. In some configurations, one or both of the barrier layers <NUM> are each produced (e.g., thermoformed or blow molded) from a monolayer film (a single layer). In other configurations, one or both of the barrier layers <NUM> 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 <NUM> micrometers to about <NUM> millimeter. In further configurations, the film thickness for each layer or sublayer can range from about <NUM> micrometers to about <NUM> micrometers. In yet further configurations, the film thickness for each layer or sublayer can range from about <NUM> micrometer to about <NUM> micrometers.

One or both of the barrier layers <NUM> 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 <NUM> 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.

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 <NUM>,<NUM>-diisocyanate (NDI), <NUM>,<NUM>-tetrahydronaphthalene diisocyanate, para-phenylene diisocyanate (PPDI), <NUM>,<NUM>' - dimethyldiphenyl-<NUM>, <NUM>' -diisocyanate (DDDI), <NUM>,<NUM> '-dibenzyl diisocyanate (DBDI), <NUM>-chloro-<NUM>,<NUM>-phenylene diisocyanate, and combinations thereof. In some configurations, the copolymer chains are substantially free of aromatic groups.

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 <NUM> may include two or more sublayers (multilayer film) such as shown in <CIT> and <CIT>. In configurations where the barrier layers <NUM> include two or more sublayers, examples of suitable multilayer films include microlayer films, such as those disclosed in <CIT>. In further configurations, the barrier layers <NUM> 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 <NUM> includes at least four (<NUM>) sublayers, at least ten (<NUM>) sublayers, at least twenty (<NUM>) sublayers, at least forty (<NUM>) sublayers, and/or at least sixty (<NUM>) sublayers.

The bladder assembly <NUM> can be produced from the barrier layers <NUM> 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 <NUM> can be produced by co-extrusion followed by vacuum thermoforming to form the profile of the bladder assembly <NUM>, which can optionally include one or more valves <NUM> (e.g., one way valves) that allows the fluid-filled chambers 106a, 106b of the bladder assembly <NUM> to be filled with the fluid (e.g., gas).

The fluid-filled chambers 106a, 106b of the bladder assembly <NUM> desirably have a low gas transmission rate to preserve its retained gas pressure. In some configurations, the fluid-filled chambers 106a, 106b have a gas transmission rate for nitrogen gas that is at least about ten (<NUM>) times lower than a nitrogen gas transmission rate for a butyl rubber layer of substantially the same dimensions. In one aspect, fluid-filled chambers 106a, 106b have a nitrogen gas transmission rate of <NUM> cubic-centimeter/square-meter•atmosphere•day (cm<NUM>/m<NUM>•atm•day) or less for an average film thickness of <NUM> micrometers (based on thicknesses of barrier layers <NUM>). In further aspects, the transmission rate is <NUM><NUM>/m<NUM>•atm•day or less, <NUM><NUM>/m<NUM>•atm•day or less, or <NUM><NUM>/m<NUM>•atm•day or less.

In the shown configuration, the barrier layers <NUM> include a first, upper barrier layer 118a forming the top side <NUM> of the fluid-filled chambers 106a, 106b, and a second, lower barrier layer 118b forming the bottom side <NUM> of the fluid-filled chambers 106a, 106b. In the illustrated example, interior, opposing surfaces (i.e. facing each other) of the barrier layers <NUM> are joined together at discrete locations to form a web area <NUM> and a peripheral seam <NUM>. The peripheral seam <NUM> extends around the outer periphery of the respective fluid-filled chambers 106a, 106b and defines an outer peripheral profile of the fluid-filled chambers 106a, 106b.

The fluid-filled chambers 106a, 106b may be referenced as a first fluid-filled chamber 106a and a second fluid-filled chamber 106b. The first fluid-filled chamber 106a is configured to be disposed in the forefoot region <NUM> and the second fluid-filled chamber 106b is configured to be disposed in the heel region <NUM>. As discussed above, the first barrier layer 118a cooperates with the second barrier layer 118b to define an interior void 124a, 124b.

With reference first to the first fluid-filled chamber 106a, the interior void 124a is asymmetric about a longitudinal axis A106a of the first fluid-filled chamber 106a. A perimeter region 126a of the interior void 124a includes a first thickness T106a-<NUM> measured in a first direction between the first barrier layer 118a and the second barrier layer 118b, as shown in <FIG>. A central region 128a, bound by the perimeter region 126a of the interior void 124a includes a second thickness T106a-<NUM> measured in the first direction that is less than the first thickness T106a-<NUM> at the perimeter region 126a of the interior void 124a.

A tensile member <NUM> is disposed within the interior void 124a and received within the central region 128a. Each tensile element <NUM> may include a series of tensile strands <NUM> extending between an upper tensile sheet <NUM> and a lower tensile sheet <NUM>. The upper tensile sheet <NUM> may be attached to the first barrier layer 118a while the lower tensile sheet <NUM> may be attached to the second barrier layer 118b. In this manner, when the first fluid-filled chamber 106a receives a pressurized fluid, the tensile strands <NUM> of the tensile member <NUM> are placed in tension. Because the upper tensile sheet <NUM> is attached to the first barrier layer 118a and the lower tensile sheet <NUM> is attached to the second barrier layer 118b, the tensile strands <NUM> retain a desired shape of the first fluid-filled chamber 106a when the pressurized fluid is injected into the interior void 124a. Additional details of tensile member <NUM> are described in <CIT>, <CIT>, and <CIT>. Alternatively, a foam structure, not shown, may be disposed within the interior void 124a.

With reference now to <FIG>, the first fluid-filled chamber 106a further includes at least two arcs <NUM> disposed between the perimeter region 126a and the central region 128a. The arcs <NUM> are spaced apart from each other by the web area <NUM> and are disposed on the anterior portion of the first fluid filled chamber 106a. The arcs <NUM> may be in fluid communication with the perimeter region 126a and the central region 128a. Alternatively, the arcs <NUM> may be sealed from the perimeter region 126a and the central region 128a. In another aspect, the arcs <NUM> may be concentric with one another. The arcs <NUM> are illustratively shown as having a constant radius. However, it should be appreciated that the arcs may be configured to having a varying radius.

The perimeter region 126a surrounds the central region 128a and the two arcs <NUM>. The perimeter region 126a may be in fluid communication with the central region 128a so as to allow for a load to be balanced between the central region 128a and the perimeter region 126a. As described above, the first fluid-filled chamber 106a may include a valve 121a that allows the fluid-filled chamber 106a to be filled with the fluid (e.g., gas) such that the interior void 124a is pressurized.

In some configurations, the perimeter region 126a includes a pair of medial lobes 140a, 140b and a pair of lateral lobes 142a, 142b. The medial lobes 140a, 140b extend along a medial side <NUM> of the first fluid-filled chamber 106a. The medial lobes 140a, 140b may be referenced as a first medial lobe 140a and a second medial lobe 140b. The first medial lobe 140a is arranged in series with the second medial lobe 140b. In one aspect, the first medial lobe 140a has a thickness and a width that may be greater than a thickness and a width of the second medial lobe 140b. As such, the first medial lobe 140a is more bulbous than the second medial lobe 140b.

The lateral lobes 142a, 142b may be referenced as a first lateral lobe 142a and a second lateral lobe 142b. The first lateral lobe 142a is arranged in series with the second lateral lobe 142b. In one aspect, the first lateral lobe 142a has a thickness and a width that may be greater than a thickness and a width of second lateral lobe 142b. As such, the first lateral lobe 142a is more bulbous than the second lateral lobe 142b.

The first medial lobe 140a is contiguous with the first lateral lobe 142a. In particular, a first end of the first medial lobe 140a is seamlessly coupled with a first end of the first lateral lobe 142a. A second end of the first medial lobe 140a is seamlessly coupled with a first end of the second medial lobe 140b. A second end of the second medial lobe 140b is seamlessly coupled to a second end of the second lateral lobe 142b. A first end of the second lateral lobe 142b is seamlessly coupled to a second end of the first lateral lobe 142a.

In one aspect, the first and the second ends of the respective medial lobes 140a, 140b and the lateral lobes 142a, 142b are smaller, in three dimensions, than a center of the respective medial lobes 140a, 140b and the lateral lobes 142a, 142b. As such, each of the respective medial lobes 140a, 140b and the lateral lobes 142a, 142b have a generally bulbous shape.

The first medial lobe 140a and the first lateral lobe 142a are generally C-shaped. A valve 121a may be disposed where the first end of the first medial lobe 140a and the first end of the first lateral lobe 142a are joined. The second medial lobe 140b and the second lateral lobe 142b are also C-shaped. The first fluid-filled chamber 106a includes a pair of neck portions 140c, 142c where the second end of the first medial lobe 140a is joined to the first end of the second medial lobe 140b and the second end of the first lateral lobe 142a is joined to the first end of the second lateral lobe 142b. The neck portions 140c, 142c have a cross-section smaller than the cross-section of the mid-portion of the first medial lobe 140a, second medial lobe 140b, first lateral lobe 140b, and second lateral lobe 142b. Collectively, the first medial lobe 140a, the second medial lobe 140b, the first lateral lobe 142a, and the second lateral lobe 142b form a generally heart shaped structure.

With reference again to <FIG>, a description of the second fluid-filled chamber 106b of the bladder assembly <NUM> is now provided. The second fluid-filled chamber 106b is configured to be disposed in the heel region <NUM>. The perimeter region 126b bounds a periphery of the second fluid-filled chamber 106b and bounds the central region 128b. The web area <NUM> bounds the central region 128b. The interior void 124b of the central region 128b may be separated from the interior void 124b of the perimeter region 126b by the web area <NUM> wherein the first barrier layer 118a and the second barrier layer 118b are adhered to each other. Alternatively, the first barrier layer 118a and the second barrier layer 118b may be spaced apart at the web area <NUM> so as to fluidly connect the perimeter region 126b to the central region 128b. The central region 128b is a bulbous member that projects both upwardly and downwardly from opposite sides of the web area <NUM>.

In some configurations, the perimeter region 126b surrounds the central region 128b. The perimeter region 126b includes a pair of medial lobes 152a, 152b and a pair of lateral lobes 154a, 154b. The pair of lateral lobes 154a, 154b extends towards the first fluid-filled chamber 106a to a greater extent than the pair of medial lobes 152a, 152b. The medial lobes 152a, 152b extend along a medial side <NUM> of the second fluid-filled chamber 106b. The medial lobes 152a, 152b may be referenced as a first medial lobe 152a and a second medial lobe 152b. The first medial lobe 152a is arranged in series with the second medial lobe 152b. In one aspect, the first medial lobe 152a has a length which is shorter than a length of the second medial lobe 152b. The first medial lobe 140a and the second medial lobe 140b are bulbous structures seamlessly connected to each other.

The lateral lobes 154a, 154b may be referenced as a first lateral lobe 154a and a second lateral lobe 154b. The first lateral lobe 154a is arranged in series with the second lateral lobe 154b. In one aspect, the first lateral lobe 154a has length shorter than a length of the second lateral lobe 154b. The first lateral lobe 154a and the second lateral lobe 154b have a bulbous shape. The second lateral lobe 154b extends into a posterior portion of the heel region <NUM>, so as to have a length greater than the length of the second medial lobe 152b of the second fluid-filled chamber 106b.

The first medial lobe 152a is fluidly connected with the first lateral lobe 154a via a posterior lobe <NUM>. The posterior lobe <NUM> has a generally uniform diameter. For illustrative purposes, the posterior lobe <NUM> is connected at an intermediate portion of the first medial lobe 152a and the first lateral lobe 154a. However, it should be appreciated that the posterior lobe <NUM> may be connected to a first end of the first medial lobe 152a and the first lateral lobe 154a. A second end of the first medial lobe 152a is seamlessly coupled with a first end of the second medial lobe 152b. A second end of the second medial lobe 152b is seamlessly coupled to a second end of the second lateral lobe 154b. A first end of the second lateral lobe 154b is seamlessly coupled to a second end of the first lateral lobe 154a.

In one aspect the first and the second ends of the respective medial lobes 152a, 152b and the lateral lobes 154a, 154b are smaller, in three dimensions, than a center of the respective medial lobes 152a, 152b and the lateral lobes 154a, 154b. As such, each of the respective medial lobes 152a, 152b and the lateral lobes 154a, 154b have a generally elongated and bulbous shape.

As described above, the second fluid-filled chamber 106a may include a valve 121b that allows the second fluid-filled chamber 106b of the bladder assembly <NUM> to be filled with the fluid (e.g., gas) such that the interior void 124b is pressurized. The second fluid-filled chamber 106b may further include a conduit <NUM> connecting the central region 128b to the perimeter region 126b. The valve 121b is configured to supply the fluid to both the central region 128b and the perimeter region 126b.

With reference again to <FIG> and <FIG>, the chassis <NUM> is configured to interface with the bladder assembly <NUM> to provide a unitary midsole <NUM>. The chassis <NUM> extends from a first end <NUM> at the anterior end <NUM> of the sole structure <NUM> to a second end <NUM> at the posterior end <NUM> of the sole structure <NUM>. The chassis <NUM> further includes a top surface <NUM> defining a portion of a footbed, and a bottom surface <NUM> formed on the opposite side of the chassis <NUM> than the top surface <NUM> and configured to interface with the top side <NUM> of the bladder assembly <NUM>.

The chassis <NUM> includes a plurality of grooves 168a, 168b formed on the bottom surface <NUM>. Here, a shape each of the grooves 168a, 168b corresponds to a shape of a corresponding perimeter region 126a, 126b and central region 128a, 128b, such that when the chassis <NUM> is assembled with the bladder assembly <NUM>, the perimeter region 126a, 126b and central region 128a, 128b are seated to the bottom surface <NUM> of the chassis <NUM>. In the illustrated example, the perimeter region 128a, 128b are configured to fully extend into the grooves 168a, 168b when the midsole <NUM> is assembled.

The chassis <NUM> 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 chassis <NUM> 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. Alternatively, the plurality of elements may not be affixed to each other, but may remain independent while contained in one or more structures forming the cushioning element. In this alternative example, the plurality of independent cushioning elements may be a plurality of foamed particles, and may contained in a bladder or shell structure. As such, the cushioning element may be formed of a plurality of foamed particles contained within a relatively translucent bladder or shell formed of a film such as a barrier membrane.

Example resilient polymeric materials for the chassis 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 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 discussed above for barrier layers <NUM>. 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 configurations, the foamed polymeric material may be a crosslinked foamed material. In these configurations, a peroxide-based crosslinking agent such as dicumyl peroxide may be used.

In some examples, the outsole <NUM> extends over the midsole <NUM> to provide increased durability and resiliency. In the illustrated example, the outsole <NUM> is provided as a polymeric layer that is overmolded onto the bladder assembly <NUM> to provide increased durability to the exposed portions of the lower barrier layer 118b of the bladder assembly <NUM>. Accordingly, the outsole <NUM> is formed of a different material than the bladder assembly <NUM>, and includes at least one of a different thickness, a different hardness, and a different abrasion resistance than the lower barrier layer 118b. In some examples, the outsole <NUM> may be formed integrally with the lower barrier layer 118b of the bladder assembly <NUM> using an overmolding process. In other examples, the outsole <NUM> may be formed separately from the lower barrier layer 118b of the bladder assembly <NUM> and may be adhesively bonded to the lower barrier layer 118b.

The upper <NUM> is attached to the sole structure <NUM> and includes interior surfaces that define an interior void configured to receive and secure a foot for support on sole structure <NUM>. The upper <NUM> may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void. Suitable materials of the upper 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.

Claim 1:
A fluid-filled chamber (106a) comprising:
a first barrier layer (118a);
a second barrier layer (118b) cooperating with the first barrier layer (118a) to define an interior void (124a) that is asymmetric about a longitudinal axis of the fluid-filled chamber (106a), the interior void (124a) including a first thickness (T106a-<NUM>) measured in a first direction between the first barrier layer (118a) and the second barrier layer (118b) at a perimeter region (126a) of the interior void (124a) and a second thickness (T106a-<NUM>) measured in the first direction that is less than the first thickness (T106a-<NUM>) at a central region (128a) of the interior void (124a);
a tensile member (<NUM>) disposed within the interior void (124a) and received only within the central region (128a); and
at least two arcs (<NUM>) disposed between the perimeter region (126a) and the central region (128a),
wherein the perimeter region (126a) surrounds the central region (128a) and the at least two arcs (<NUM>).