Patent Description:
<CIT> discloses a bladder for a shoe midsole wherein the bladder comprises a plurality of distinct chambers.

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 bladders typically include a bladder formed from two barrier layers of polymer material that are sealed or bonded together. The bladders may contain air, and may incorporate tensile members within the bladder to retain the shape of the bladder when pressurized. 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.

In one aspect of the disclosure, a bladder for an article of footwear is provided. The bladder extends from an anterior end to a posterior end and includes a first chamber disposed in an interior region of the bladder and including a first interior void having a first pressure, and a second chamber at least partially surrounding the first chamber and including a second interior void having a second pressure.

Implementations of the disclosure may include one or more of the following optional features.

In some examples, the bladder has a first width adjacent to the anterior end of the bladder, a second width adjacent to the posterior end of the bladder, and a third width in an intermediate portion that is less than the first width and the second width.

In some configurations, the second chamber includes an anterior portion having a first cross-sectional area, a posterior portion having a second cross-sectional area, and an intermediate portion connecting the anterior portion and the posterior portion and having a third cross-sectional area. Here, the third cross-sectional area may be less than the first cross-sectional area. Optionally, the third cross-sectional area may be less than the second cross-sectional area. In some examples, the third cross-sectional area may be less than the first cross-sectional area and the second cross-sectional area.

The bladder includes a web area disposed between and connecting the first chamber and the second chamber.

In some examples, the bladder includes a first barrier layer and a second barrier layer joined together at discrete locations to define the first chamber and the second chamber. Optionally, at least one of the first barrier layer and the second barrier layer is transparent. In some examples, at least one of the first barrier layer and the second barrier layer is translucent.

In some configurations, the second chamber completely surrounds the first chamber.

In some examples, the second chamber partially surrounds the first chamber.

In some implementations, the second chamber includes a plurality of lobes, each lobe having a first end, a second end, and an intermediate portion disposed between the first end and the second end and being larger than the first end and the second end. Here, each lobe may taper from the intermediate portion to the first end and the second end. For each lobe, a thickness of the intermediate portion may be greater than thicknesses of the first end and the second end. Additionally or alternatively, for each lobe, a width of the intermediate portion is greater than widths of the first end and the second end. In some examples, a cross-sectional area of the intermediate portion is greater than the cross-sectional areas of the first end and the second end. Optionally, a plurality of the lobes are arranged in series around the first chamber.

In some examples, the plurality of lobes includes a medial anterior lobe and a lateral anterior lobe. Here, the medial anterior lobe and the lateral anterior lobe may be in direct fluid communication with each other.

In some implementations, the plurality of lobes includes a posterior lobe disposed at the posterior end of the bladder. Here, the posterior lobe may extend from a first end on a medial side of the bladder to a second end on a lateral side of the bladder. In some configurations plurality of lobes includes a lateral intermediate lobe and a medial intermediate lobe in direct fluid communication with the posterior lobe. Here, the lateral intermediate lobe and the medial intermediate lobe may be smaller than the posterior lobe. In some examples, a cross-sectional area of an interior void of the second chamber is greater at the intermediate portion of the posterior lobe than at the intermediate portions of each of the lateral intermediate lobe and the medial intermediate lobe. In some examples, a thickness of the intermediate portion of the posterior lobe defines a maximum thickness of the bladder.

In some implementations, the plurality of lobes includes a lateral intermediate lobe and a medial intermediate lobe disposed between the anterior end and the posterior end of the bladder.

In some examples, the first pressure is different than the second pressure. In some examples, the second pressure is greater than the first pressure. In some configurations, the first pressure ranges from <NUM> psi to <NUM> psi. In some implementations, the first pressure ranges from <NUM> psi to <NUM> psi. In some examples, the first pressure ranges from <NUM> psi to <NUM> psi. In some examples, the second pressure ranges from <NUM> psi to <NUM> psi. In some configurations, the second pressure ranges from <NUM> psi to <NUM> psi. In some implementations, the second pressure ranges from <NUM> psi to <NUM> psi. In some examples, the first pressure and the second pressure are atmospheric pressure.

In some configurations, a first thickness of the first chamber is greater than a second thickness of the second chamber at the anterior end and less than a third thickness of the second chamber at the posterior end.

Another aspect of the disclosure includes a sole structure including the bladder of any of the preceding clauses.

Another aspect of the disclosure is directed towards an article of footwear including the bladder described in the preceding paragraphs.

In another aspect of the disclosure, a sole structure is provided. The sole structure has a chassis including a bottom surface forming a first portion of the chassis and a recessed surface offset from the bottom surface to define a recess in a second portion of the chassis. The sole structure further includes a bladder disposed within the recess of the chassis and including a first chamber disposed in an interior region of the recess and a second chamber disposed in a peripheral region of the recess. The second chamber at least partially surrounds the first chamber and is fluidly isolated from the first chamber.

In some examples, the second chamber completely surrounds the first chamber.

In some implementations, the second chamber partially surrounds the first chamber.

In some configurations, the first chamber has a different pressure than the second chamber.

In some examples, the chassis includes a cushioning element forming the bottom surface and the interior region of the recesses surface, and a cradle at least partially defining the peripheral region of the recessed surface, the cradle being formed of a different material than the cushioning element.

In some configurations, the recessed surface includes a plurality of supports each configured to interface with a respective lobe of the bladder. Here, a first one of the supports may be formed of a first material and a second one of the supports may be formed of a second material that is different than the first material. Optionally, the plurality of supports includes an interior support interfacing with the first chamber and a plurality of peripheral supports each interfacing with a respective lobe of the second chamber.

In some examples, the sole structure includes an outsole having a first portion attached to the chassis and a second portion attached to the bladder. Here, the second portion of the outsole optionally includes an interior portion attached to the first chamber and a peripheral portion attached to the second chamber and independently movable relative to the interior portion.

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 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 lateral side <NUM> and a medial side <NUM>, as shown in <FIG>. Accordingly, the lateral side <NUM> and the medial 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 lateral side <NUM> and the medial 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>, 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 <NUM> 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 <NUM> and a chassis <NUM>, where the chassis <NUM> is attached to the upper <NUM> and provides an interface between the upper <NUM>, the bladder <NUM>, and the outsole <NUM>.

With reference to <FIG> and <FIG>, the bladder <NUM> of the midsole <NUM> may be described as extending along a longitudinal axis A<NUM> from a first, anterior end <NUM> to a second, posterior end <NUM> disposed at an opposite end of the bladder <NUM> than the anterior end <NUM>. When incorporated into the article of footwear <NUM>, the anterior end <NUM> of the bladder <NUM> is disposed within the heel region <NUM> or the midfoot region <NUM> and faces the anterior end <NUM> of the footwear <NUM>, while the posterior end <NUM> is disposed at the posterior end <NUM> of the footwear <NUM>. The bladder <NUM> may be further described as including an intermediate region <NUM> disposed between the anterior end <NUM> and the posterior end <NUM>. The geometry and features of the bladder <NUM> may also be described relative to the peripheral region <NUM> and the interior region <NUM> of the article of footwear <NUM>.

As shown in the cross-sectional views of <FIG>, the bladder <NUM> may be formed by an opposing pair of barrier layers <NUM>, <NUM>, which can be j oined to each other at discrete locations to define an overall shape of the bladder <NUM>. Alternatively, the bladder <NUM> can be produced from any suitable combination of one or more barrier layers.

As used herein, the term "barrier layer" (e.g., barrier layers <NUM>, <NUM>) encompasses both monolayer and multilayer films. In some embodiments, one or both of the barrier layers <NUM>, <NUM> 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 <NUM>, <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 be about <NUM> millimeter. In further embodiments, the film thickness for each layer or sublayer can range from about <NUM> micrometers to about <NUM> micrometers. In yet further embodiments, 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>, <NUM> can independently be transparent, translucent, and/or opaque. As used herein, the term "transparent" for a barrier layer and/or a fluid-filled chamber 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>, <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>' - dimethyldipheny1-<NUM>, <NUM>' -diisocyanate (DDDI), <NUM>,<NUM> '-dibenzyl diisocyanate (DBDI), <NUM>-chloro-<NUM>,<NUM>-phenylene diisocyanate, and combinations thereof. In some embodiments, 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>, <NUM> may include two or more sublayers (multilayer film) such as shown in <CIT> and <CIT>. In embodiments where the barrier layers <NUM>, <NUM> include two or more sublayers, examples of suitable multilayer films include microlayer films, such as those disclosed in <CIT>. In further embodiments, the barrier layers <NUM>, <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>, <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 <NUM> can be produced from the barrier layers <NUM>, <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>, <NUM> can be produced by coextrusion followed by vacuum thermoforming to form the profile of the bladder <NUM>, which can optionally include one or more valves <NUM> (e.g., one way valves) that allows the bladder <NUM> to be filled with the fluid (e.g., gas).

The bladder <NUM> desirably has a low gas transmission rate to preserve its retained gas pressure. In some embodiments, the bladder <NUM> has 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 an aspect, bladder <NUM> has 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>, <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 embodiment, the barrier layers <NUM>, <NUM> include a first, upper barrier layer <NUM> and a second, lower barrier layer <NUM>. Each of the barrier layers <NUM>, <NUM> includes an interior surface <NUM>, <NUM> and a respective exterior surface <NUM>, <NUM> formed on an opposite side of the barrier layer <NUM>, <NUM> from the interior surface <NUM>, <NUM>. The exterior surface <NUM> of the upper barrier layer <NUM> defines an upper surface of the bladder <NUM> and the exterior surface <NUM> of the lower barrier layer <NUM> defines a lower surface of the bladder <NUM>. As discussed below, thicknesses of the bladder <NUM> are defined by distances from the exterior surface <NUM> of the upper barrier layer <NUM> to the exterior surface <NUM> of the lower barrier layer <NUM>, measured along a vertical direction (i.e., perpendicular to the ground surface).

The interior surfaces <NUM>, <NUM> of the barrier layers <NUM>, <NUM> are joined together at discrete locations to define a plurality of chambers <NUM>, <NUM>. As shown in <FIG>, the interior surfaces <NUM>, <NUM> of the upper and lower barrier layers <NUM>, <NUM> are spaced apart from each other to define respective interior voids <NUM>, <NUM> of each of the chambers <NUM>, <NUM>, while the interior surfaces <NUM>, <NUM> are joined or attached to each other to form a web area <NUM> and a peripheral seam <NUM> surrounding each of the chambers <NUM>, <NUM>.

The bladder <NUM> includes a first, interior chamber <NUM> disposed in the interior region <NUM> of the bladder <NUM> and a second, peripheral chamber <NUM> surrounding the interior chamber <NUM>. The web area <NUM> surrounds the interior chamber <NUM> and separates the interior chamber <NUM> from the peripheral chamber <NUM> such that the interior voids <NUM>, <NUM> of the interior chamber <NUM> and the peripheral chamber <NUM> are isolated from each other (i.e., fluid or media cannot transfer between the interior voids <NUM>, <NUM>). The peripheral seam <NUM> extends around the outer periphery of the peripheral chamber <NUM> and defines an outer peripheral profile of the bladder <NUM>.

As shown in <FIG> and <FIG>, the interior chamber <NUM> extends continuously along the longitudinal axis A<NUM> of the bladder from an anterior end <NUM> at the anterior end <NUM> of the bladder <NUM> to a posterior end <NUM> at the posterior end <NUM> of the bladder <NUM>. When incorporated within the article of footwear <NUM>, the interior chamber <NUM> is configured to support a central portion of the heel corresponding to the bottom of the calcaneus bone, while the peripheral chamber <NUM> provides a separate support structure that receives a portion of the heel therein.

A distance from the anterior end <NUM> to the posterior end <NUM> defines a length L<NUM> of the interior chamber <NUM>. The interior chamber <NUM> may be described as including an intermediate portion <NUM> disposed between the anterior end <NUM> and the posterior end <NUM>. The interior chamber <NUM> may be further defined by a lateral side <NUM> and a medial side <NUM> each extending along opposite sides of the interior chamber <NUM> from the anterior end <NUM> to the posterior end <NUM>, whereby a width W<NUM> of the interior chamber <NUM> is defined by a lateral distance (i.e., perpendicular to the longitudinal axis A<NUM>) from the lateral side <NUM> to the medial side <NUM>. As provided above, thicknesses T<NUM> (<FIG>) of the interior chamber <NUM> are defined by the distance from the exterior surface <NUM> of the upper barrier layer <NUM> to the exterior surface <NUM> of the lower barrier layer <NUM> along the length L<NUM> and width W<NUM> of the interior chamber <NUM>.

Referring to <FIG>, <FIG>, and <FIG>, the interior chamber <NUM> may be configured such that at least one of the width W<NUM> and the thickness T<NUM> tapers along a lengthwise direction of the longitudinal axis A<NUM> of the bladder <NUM>. Particularly, the interior chamber <NUM> may have a greater width W<NUM> and/or thickness T<NUM> in the intermediate portion <NUM> than at one or both of the ends <NUM>, <NUM>. Accordingly, the cross-sectional area of the interior chamber <NUM> may also taper from the intermediate portion <NUM> to each of the ends <NUM>, <NUM>. In the illustrated example, the interior chamber <NUM> is formed as an ovoid, whereby the exterior surfaces <NUM>, <NUM> of the upper barrier layer <NUM> and the lower barrier layer <NUM> are both convex in shape and each of the sides <NUM>, <NUM> extends along an arcuate path. However, in other examples, either or both of the barrier layers <NUM>, <NUM> may have other geometries, and at least a portion of the interior chamber <NUM> may have a constant cross-sectional area.

With continued reference to <FIG> and <FIG>, the peripheral chamber <NUM> extends along the peripheral region <NUM> from the anterior end <NUM> to the posterior end <NUM> of the bladder <NUM>. As shown, the peripheral chamber <NUM> completely surrounds the interior chamber <NUM> such that the interior void <NUM> of the peripheral chamber <NUM> is interminable. As shown, an overall length L<NUM> and width W<NUM> of the bladder <NUM> are defined by the peripheral chamber <NUM>, and more particularly, by the peripheral seam <NUM>.

Referring now to <FIG>, the peripheral chamber <NUM> is formed with a variable cross-section, such that at least one of a width W<NUM> and a thickness T<NUM> of the peripheral chamber <NUM> changes along a length of the peripheral chamber <NUM>. Here, the width W<NUM> of the peripheral chamber is defined as a distance across the peripheral chamber <NUM> from the web area <NUM> to the peripheral seam <NUM>, while the thickness T<NUM> is defined by the distances between the exterior surfaces <NUM>, <NUM> of the bladder <NUM>.

Referring to <FIG>, the peripheral chamber <NUM> may include a plurality of lobes 152a-152e each forming a portion of the peripheral chamber <NUM> having a variable cross-sectional area. For example, each of the lobes 152a-152e includes a first end 154a-154e having a first cross-sectional area, a second end 156a-156e having a second cross-sectional area, and an intermediate portion 158a-158e disposed between the first end 154a-154e and the second end 156a-156e and having a third cross-sectional area that is greater than the first cross-sectional area and the second cross-sectional area. Accordingly, each of the lobes 152a-152e tapers towards the respective first end 154a-154e and second end 156a-156e from the intermediate portion 158a-158e. In some examples, both the width W<NUM> and the thickness T<NUM> of each of the lobes 152a-152e tapers from the intermediate portion 158a-158e.

As shown in <FIG>, the variable cross section of the peripheral chamber <NUM> results in the overall width W<NUM> of the bladder <NUM> being variable from the anterior end <NUM> to the posterior end <NUM>. Particularly, the bladder <NUM> has a first width W<NUM>-<NUM> across the intermediate portions 158a, 158b of the anterior lobes 152a, 152b adjacent to the anterior end <NUM>, a second width W<NUM>-<NUM> across the second ends 156a, 156b of the anterior lobes 152a, 152b in the intermediate region <NUM>, and a third width W<NUM>-<NUM> across the intermediate portions 158d, 158e of the intermediate lobes 152d, 152e adjacent to the posterior end <NUM>. Here, the second width W<NUM>-<NUM> is less than the first width W<NUM>-<NUM> and the third width W<NUM>-<NUM>, while the third width W<NUM>-<NUM> is greater than the first width W<NUM>-<NUM> and the second width W<NUM>-<NUM>.

The illustrated example of the bladder <NUM> includes a plurality of the lobes 152a-152e arranged end-to-end in series around the interior chamber <NUM> such that the cross-sectional area of the peripheral chamber <NUM> alternates between larger and smaller sizes. As shown, the plurality of the lobes 152a-152e includes a first pair of anterior lobes 152a, 152b disposed at the anterior end <NUM> of the bladder <NUM>, a posterior lobe 152c disposed at the posterior end <NUM> of the bladder <NUM>, and a pair of intermediate lobes 152d, 152e disposed in the intermediate region <NUM> of the bladder <NUM>.

The anterior lobes 152a, 152b of the peripheral chamber <NUM> include a lateral peripheral lobe 152a disposed at the anterior end <NUM> on the lateral side <NUM> of the bladder <NUM>, and a medial peripheral lobe 152b disposed at the anterior end <NUM> on the medial side <NUM> of the bladder <NUM>. As shown, the first ends 154a, 154b of the anterior lobes 152a, 152b are connected to each other at the longitudinal axis A<NUM> of the bladder <NUM>. Each of the anterior lobes 152a, 152b extends from its respective first end 154a, 154b and around the anterior end <NUM> of the interior chamber <NUM> to its respective second end 156a, 156b in the intermediate region <NUM> of the bladder <NUM>. In the illustrated example, the anterior lobes 152a, 152b provide the peripheral chamber <NUM> with an increased width W<NUM> at the lateral and medial sides of the anterior end <NUM> such that the anterior lobes 152a, 152b form a pair of forward-protruding portions at opposite sides of the anterior end <NUM> of the bladder <NUM>.

With continued reference to <FIG> and <FIG>, the posterior lobe 152c is disposed at the posterior end <NUM> of the bladder <NUM> and the intermediate portion 158c of the posterior lobe 152c is centrally positioned along the longitudinal axis A<NUM> of the bladder <NUM>. In the illustrated example, the posterior lobe 152c extends around the posterior end <NUM> of the interior chamber <NUM> from a first end 154a on the lateral side <NUM> of the bladder <NUM> to a second end 156c on the medial side <NUM> of the bladder <NUM>. As discussed above, the intermediate portion 158c has a greater cross-sectional area than each of the ends 154c, 156c.

The intermediate lobes 152d, 152e of the peripheral chamber <NUM> include a lateral intermediate lobe 152d disposed in the intermediate region <NUM> on the lateral side <NUM> of the bladder <NUM>, and a medial intermediate lobe 152e disposed in the intermediate region <NUM> on the medial side <NUM> of the bladder <NUM>. As shown, first ends 154d, 154e of the intermediate lobes 152d, 152e are connected to the second ends 156a, 156b of the lateral and medial anterior lobes 152a, 152b, respectively. The second end 156d of the lateral intermediate lobe 152d is connected to the first end 154c of the posterior lobe 152c at the posterior end <NUM> of the bladder <NUM>. Likewise, the second end 156e of the medial intermediate lobe 152e is connected to the second end 156c of the posterior lobe 152c at the posterior end <NUM> of the bladder <NUM>. Similar to the anterior lobes 152a, 152b at the anterior end <NUM> and the posterior lobe 152c at the posterior end <NUM>, the intermediate lobes 152d, 152e provide the peripheral chamber <NUM> with protruding portions along the lateral and medial sides <NUM>, <NUM> of the intermediate region <NUM> of the bladder <NUM>.

Referring now to <FIG>, the thickness T<NUM> the bladder <NUM> generally increases along a direction from the anterior end <NUM> to the posterior end <NUM>. However, as discussed above, because the peripheral chamber <NUM> is formed with a variable cross section, the change in thickness is not constant T<NUM> and continuous along the length of the bladder <NUM>. Instead, the thickness of the bladder <NUM> incrementally increases along the length L<NUM> of the bladder <NUM>. For example, the bladder <NUM> has a first thickness T<NUM>-<NUM> at the anterior end <NUM> defined by the intermediate portions 158a, 158b of the anterior lobes 152a, 152b, a second thickness T<NUM>-<NUM> in the intermediate region <NUM> defined by the intermediate portions 158d, 158e of the intermediate lobes 152d, 152e, and a third thickness T<NUM>-<NUM> at the posterior end <NUM> defined by the intermediate portion 158c of the posterior lobe 152c. Here, the second thickness T<NUM>-<NUM> is greater than the first thickness T<NUM>-<NUM> and less than the third thickness T<NUM>-<NUM>, such that an average thickness of the bladder <NUM> increases from the anterior end <NUM> to the posterior end <NUM>. Furthermore, as shown in the cross-sectional view of <FIG>, the thickness of the bladder <NUM> also incrementally increases along the longitudinal axis A<NUM>. Accordingly, the bladder <NUM> has a thickness T<NUM>-<NUM> at the first ends 154a, 154b of the anterior lobes 152a, 152b that is less than the thickness T<NUM> of the interior chamber <NUM>, which is, in turn, less than the thickness T<NUM>-<NUM> at the posterior lobe 152c.

The chambers <NUM>, <NUM> can be provided in a fluid-filled (e.g., as provided in footwear <NUM>) or in an unfilled state. The chambers <NUM>, <NUM> can be filled to include any suitable fluid, such as a gas or liquid. In an aspect, the gas can include air, nitrogen (N<NUM>), or any other suitable gas. The fluid provided to the chambers <NUM>, <NUM> can result in the bladder <NUM> being pressurized. Alternatively, the fluid provided to the chambers <NUM>, <NUM> can be at atmospheric pressure such that the chambers <NUM>, <NUM> are not pressurized but, rather, simply contains a volume of fluid at atmospheric pressure. In other aspects, the chambers <NUM>, <NUM> can alternatively include other compressible media, such as pellets, beads, ground recycled material, and the like (e.g., foamed beads and/or rubber beads).

In the illustrated example, the interior void <NUM> of the interior chamber <NUM> includes a first fluid at a first pressure and the interior void <NUM> of the peripheral chamber <NUM> includes a second fluid at a second pressure. As discussed above, the interior chamber <NUM> is isolated from the peripheral chamber <NUM> such that the first pressure and the second pressure may be independently maintained within the interior voids <NUM>, <NUM>. The first pressure and the second pressure may be different from each other. For instance, the first pressure within the interior void <NUM> of the interior chamber <NUM> may be less than the second pressure within the interior void <NUM> of the peripheral chamber <NUM> when the bladder <NUM> is in an uncompressed (i.e., natural) state. In some examples, the first pressure ranges from <NUM> psi to <NUM> psi, and more particularly from <NUM> psi to <NUM> psi, and even more particularly from <NUM> psi to <NUM> psi. The second pressure may range from <NUM> psi to <NUM> psi, and more particularly from <NUM> psi to <NUM> psi, and even more particularly from <NUM> psi to <NUM> psi.

Providing the bladder <NUM> with an interior chamber <NUM> having a lower pressure than the surrounding peripheral chamber <NUM> allows the interior chamber <NUM> to provide a softer cushioning response to a point load applied by the central portion of the heel when sole structure <NUM> contacts a ground surface. Upon initial compression of the interior chamber <NUM>, the higher pressure of the peripheral chamber <NUM> provides secondary cushioning around a perimeter of the heel. Furthermore, the higher pressure of the peripheral chamber <NUM> provides the heel region with enhanced lateral (i.e., side-to-side, front-to-back) stability. Thus, the dual-chamber configuration of the bladder <NUM> advantageously provides both impact attenuation and stability.

With continued reference to <FIG>, the chassis <NUM> of the sole structure <NUM> extends continuously from the anterior end <NUM> to the posterior end <NUM>. The chassis <NUM> includes a top surface <NUM> defining a profile of a footbed of the article of footwear <NUM>. The chassis <NUM> further includes a bottom surface <NUM> and a recessed surface <NUM> formed on an opposite side of the chassis <NUM> than the top surface <NUM>. In the illustrated example, the bottom surface <NUM> extends from the anterior end <NUM> of the sole structure <NUM> and terminates at an intermediate portion of the chassis <NUM> in the midfoot region <NUM>.

The recessed surface <NUM> is spaced between the top surface <NUM> and the bottom surface <NUM>, and defines a recess <NUM> in the heel region <NUM> of the sole structure <NUM> that is configured to receive the bladder <NUM>. Thus, a depth or height of the recess <NUM> is defined by the offset distance between the bottom surface <NUM> and the recessed surface <NUM>. Here, the height of the recess <NUM> is configured such that when the bladder <NUM> is disposed within the recess <NUM>, the lower surface <NUM> of the bladder <NUM> and the bottom surface <NUM> of the chassis <NUM> will cooperate to form a bottom support surface of the midsole <NUM> that attaches to the outsole <NUM>.

As best shown in <FIG>, the recessed surface <NUM> may include one or more supports <NUM> configured to interface with the bladder <NUM>. Particularly, the one or more supports <NUM>-168e are configured as protruding portions of the recessed surface <NUM> that oppose the upper barrier layer <NUM> of the bladder <NUM>. Accordingly, compression forces applied to the top surface <NUM> of the chassis <NUM> in the heel region <NUM> are transferred to the bladder <NUM> as localized loads by the one or more supports <NUM>-168e. Thus, the chassis <NUM> is not in continuous contact with the upper barrier layer <NUM>, but instead contacts the upper barrier layer <NUM> at one or more discrete interfaces between a lower support surface <NUM> of each support <NUM>-168e and the upper barrier layer <NUM>. For example, the lower support surfaces <NUM>-170e of the supports <NUM>-168e may be configured to contact the uppermost portions of the upper barrier layer <NUM>.

In the illustrated example, the one or more supports <NUM> includes an interior support <NUM>-168e formed in the interior region <NUM> of the recessed surface <NUM> and configured to oppose the portion of the upper barrier layer <NUM> forming the interior chamber <NUM>. The chassis <NUM> further includes a plurality of peripheral supports 168a-168e each configured to interface with a respective one of the lobes 152a-152e of the peripheral chamber <NUM>. Thus, the chassis <NUM> is attached to the bladder <NUM> at the uppermost portions of the interior chamber <NUM> and each of the lobes 152a-152e, while lower portions of the upper barrier layer <NUM> (i.e., adjacent to and including the web area <NUM>) are spaced apart and detached from the chassis <NUM>.

Optionally, the chassis <NUM> may be formed as a unitary body or as a composite structure. For instance, in the illustrated example, the chassis <NUM> is formed as a composite, multi-part structure including a cushioning element <NUM> and a cradle <NUM>. The cushioning element <NUM> is formed as a first part and extends from the anterior end <NUM> to the posterior end <NUM>. The cushioning element <NUM> defines the top surface <NUM> and the bottom surface <NUM> of the chassis <NUM>. The cushioning element <NUM> further defines a portion of the recessed surface <NUM> in the interior region <NUM> of the chassis <NUM> such that the interior support <NUM> is included in the cushioning element <NUM>.

The cradle <NUM> may be formed as a second part and attached to the cushioning element <NUM>. Here, the cradle <NUM> extends around the peripheral region <NUM> of the chassis <NUM> in the midfoot and heel regions <NUM>, <NUM>. A portion of the recessed surface <NUM> in the peripheral region <NUM> of the chassis <NUM> is defined by the cradle <NUM>. Particularly, the cradle <NUM> may include one or more of the peripheral supports 168a-168e. In the illustrated example, the cradle <NUM> includes all of the peripheral supports 168a-168e. Accordingly, the interior support <NUM> is formed by the cushioning element <NUM> and the peripheral supports 168a-168e are formed by the cradle <NUM>.

Referring to <FIG>, the cradle <NUM> may further include a peripheral wall <NUM> that extends upwardly from the recessed surface and at least partially surrounds the upper <NUM> to provide lateral support around an outer periphery of the sole structure <NUM> and the upper <NUM>. Optionally, the peripheral wall <NUM> may have an undulated profile, such that a height H<NUM> of the peripheral wall <NUM> varies along the outer periphery of the upper <NUM>. In some examples, the peripheral wall <NUM> of the cradle <NUM> may cooperate with a peripheral wall <NUM> of the cushioning element <NUM> to provide lateral support around the upper <NUM>.

In examples where the chassis <NUM> is formed as a composite structure including the cushioning element <NUM> and the cradle <NUM>, the cushioning element <NUM> and the cradle <NUM> may be formed of materials having different properties. For example, the cushioning element <NUM> may include first materials configured to provide desired levels of cushioning and impact attenuation, while the cradle <NUM> is formed of one or more materials configured to impart a greater degree of stiffness to the heel region <NUM> of the chassis <NUM>. In some examples, the cushioning element <NUM> may be formed in part of a first foam material and the cradle may be formed in part of a second foam material having a greater stiffness and/or density than the first foam material. As such, the interior support <NUM> that is formed by the cushioning element <NUM> may have different properties than the peripheral supports 168a-168e that are formed by the cradle <NUM>. However, as provided above, the inclusion of the cradle <NUM> is optional, such that the entire chassis <NUM> may be formed as a unitary structure where all of the supports <NUM>-168e are formed of the same material.

With continued reference to <FIG>, the outsole <NUM> is configured to be attached to the midsole <NUM> to provide a durable ground-engaging surface <NUM> to the sole structure <NUM>. The outsole <NUM> includes a top surface <NUM> that attaches to the bottom support surface <NUM>, <NUM> of the midsole <NUM>, and a bottom surface <NUM> formed on an opposite side of the outsole <NUM> than the top surface <NUM>. The outsole <NUM> may be described as including a first portion <NUM> attached to the bottom surface <NUM> of the chassis <NUM> and a second portion <NUM> attached to the lower surface <NUM> of the bladder <NUM>. As shown, the outsole <NUM> is formed as a unitary structure such that the first portion <NUM> and the second portion <NUM> are attached to each other and effectively connect the lower surface <NUM> of the bladder <NUM> and the bottom surface <NUM> of the chassis <NUM> along the bottom of the sole structure <NUM>.

With continued reference to <FIG> and <FIG>, the second portion <NUM> of the outsole <NUM> may include an interior portion <NUM> associated with the interior chamber <NUM> and a peripheral portion <NUM> associated with the peripheral chamber <NUM>. The interior portion <NUM> of the outsole <NUM> is attached to a portion of the lower barrier layer <NUM> forming the interior chamber <NUM> while the peripheral portion <NUM> is attached to a portion of the lower barrier layer <NUM> forming the peripheral chamber <NUM>.

In some examples, the interior portion <NUM> and the peripheral portion <NUM> are formed separately from each other such that peripheral portion <NUM> can move completely independently from the interior portion <NUM>. In this configuration, the interior portion <NUM> may be spaced apart and separated from the peripheral portion <NUM> such that the bladder <NUM> is exposed therebetween. Optionally, the second portion <NUM> of the outsole <NUM> may include a flexure <NUM> disposed between and connecting the interior portion <NUM> and the peripheral portion <NUM>. The flexure <NUM> is configured to allow the peripheral portion <NUM> to move relatively independently from the interior portion <NUM>. For example, the flexure <NUM> may be detached and spaced apart from the bladder <NUM>, and/or may be formed with different properties (e.g., stiffness, thickness) than the interior and peripheral portions <NUM>, <NUM> to allow relative movement thereof.

With continued reference to <FIG>, the outsole <NUM> may be overmolded on the lower barrier layer <NUM> of the bladder <NUM> to correspond to the features of the bladder <NUM>. For example, the peripheral portion <NUM> of the outsole <NUM> may be formed with lobes 194a-194e corresponding to the lobes 152a-152e of the peripheral chamber <NUM>, while the interior portion <NUM> of the outsole <NUM> conforms to the shape of the interior chamber <NUM>. As shown in <FIG>, overmolding the outsole <NUM> onto the lobes 152a-152e of the bladder <NUM> provides the outsole <NUM> and the sole structure <NUM> with a series of compressible contact points along the ground-engaging surface <NUM>.

The upper <NUM> is attached to the sole structure <NUM> and includes interior surfaces that define an interior void <NUM> 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 <NUM>. 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.

With particular reference to <FIG> and <FIG>, an article of footwear 10a is provided and includes a sole structure 100a and the upper <NUM> attached to the sole structure 100a. In view of the substantial similarity in structure and function of the components associated with the article of footwear <NUM> with respect to the article of footwear 10a, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions are used to identify those components that have been modified.

In the illustrated example, the sole structure 100a includes a midsole 102a and an outsole 104a having similar characteristics and configurations as the midsole <NUM> and the outsole <NUM> described above. However, the midsole 102a of this example includes a bladder 106a having the interior chamber <NUM> and a peripheral chamber 132a that only partially surrounds the interior chamber <NUM>. For example, as shown in <FIG>, the peripheral chamber 132a includes a first terminal end 196a and a second terminal end 196b disposed at the anterior end <NUM> of the bladder 106a. As shown, the peripheral chamber 132a extends along the lateral side <NUM> of the interior chamber <NUM> from the first terminal end 196a, around the posterior end <NUM> of the interior chamber <NUM> at the posterior end <NUM> of the bladder <NUM>, and along the medial side <NUM> of the interior chamber <NUM> to the second terminal end 196b. Accordingly, the peripheral chamber 132a of the bladder 106a may be described as being a U-shaped or horseshoe-shaped structure.

With continued reference to <FIG>, the terminal ends 196a, 196b of the peripheral chamber 132a are spaced apart from each other along the lateral direction at the anterior end <NUM>. Here, the web area 138a may extend between and connect the terminal ends 196a, 196b at the anterior end <NUM>. Optionally, the web area 138a may include a valve 121a that provides fluid communication with the interior chamber <NUM> and the peripheral chamber 132a during a manufacturing process of the bladder 106a.

As discussed above with respect to the bladder <NUM>, the peripheral chamber 132a of the bladder 106a includes one or more of the lobes 152f-<NUM>. In the illustrated example, the peripheral chamber 132a includes a lateral anterior lobe 152f disposed at the first terminal end 196a on the lateral side <NUM> of the bladder 106a, and a medial anterior lobe <NUM> disposed at the second terminal end 196b on the medial side <NUM> of the bladder 106a. The peripheral chamber 132a further includes a posterior lobe <NUM> disposed at the posterior end <NUM> of the bladder 106a. In this example, the posterior lobe <NUM> may extend from a first end <NUM> that is connected to a second end 156f of the lateral anterior lobe 152f in the intermediate region <NUM> of the bladder 106a, to a second end <NUM> that is connected to a second end <NUM> of the medial anterior lobe <NUM> in the intermediate region <NUM> of the bladder 106a.

As shown in <FIG>, the variable cross section of the peripheral chamber 132a results in the overall width W106a of the bladder 106a being variable from the anterior end <NUM> to the posterior end <NUM>. Particularly, the bladder 106a has a first width W106a-<NUM> across the intermediate portions 158f, <NUM> of the anterior lobes 152f, <NUM> adjacent to the anterior end <NUM>, a second width W106a-<NUM> across the second ends 156f, <NUM> of the anterior lobes 152f, <NUM> in the intermediate region <NUM>, and a third width W106a-<NUM> across the posterior lobe <NUM> at the first and second ends <NUM>, <NUM>. Here, the second width W106a-<NUM> is less than the first width W106a-<NUM> and the third width W106a-<NUM>, while the third width W106a-<NUM> is greater than the first width W106a-<NUM> and the second width W106a-<NUM>.

In the illustrated example, the interior void <NUM> of the interior chamber <NUM> includes a first fluid at a first pressure and the interior void 136a of the peripheral chamber 132a includes a second fluid at a second pressure. As discussed above, the interior chamber <NUM> is isolated from the peripheral chamber <NUM> such that the first pressure and the second pressure may be independently maintained within the interior voids <NUM>, 136a. The first pressure and the second pressure may be different from each other. For instance, the first pressure within the interior void <NUM> of the interior chamber <NUM> may be less than the second pressure within the interior void 136a of the peripheral chamber 132a when the bladder <NUM> is in an uncompressed (i.e., natural) state. In some examples, the first pressure ranges from <NUM> psi to <NUM> psi, and more particularly from <NUM> psi to <NUM> psi, and even more particularly from <NUM> psi to <NUM> psi. The second pressure may range from <NUM> psi to <NUM> psi, and more particularly from <NUM> psi to <NUM> psi, and even more particularly from <NUM> psi to <NUM> psi.

With particular reference to <FIG> and <FIG>, an article of footwear 10b is provided and includes a sole structure 100b and the upper <NUM> attached to the sole structure 100b. In view of the substantial similarity in structure and function of the components associated with the article of footwear <NUM> with respect to the article of footwear 10b, like reference numerals are used hereinafter and in the drawings to identify like components while like reference numerals containing letter extensions are used to identify those components that have been modified.

In the illustrated example, the sole structure 100b includes a midsole 102b and an outsole 104b having similar characteristics and configurations as the midsoles <NUM>, 102a and the outsoles <NUM>, 104a described above. Here, the bladder 106b is formed with the interior chamber <NUM> and a peripheral chamber 132b, where the peripheral chamber 132b is interminable and includes an elongate posterior lobe <NUM> extending around the posterior end <NUM> of the bladder 106b. Optionally, the peripheral chamber 132b may include a valve 121a that provides fluid communication with the interior chamber <NUM> and the peripheral chamber 132b during a manufacturing process of the bladder 106a.

As shown, the peripheral chamber 132b of the bladder 106b includes a series of the lobes 152i-<NUM> including a lateral anterior lobe 152i disposed at the anterior end <NUM> on the lateral side <NUM>, and a medial anterior lobe 152j disposed at the anterior end <NUM> on the medial side <NUM>. Here, the first ends 154i, 154j of the anterior lobes 152i, 152j are connected to each other along the longitudinal axis A106b of the bladder 106b and the second ends 156i, 156j of the anterior lobes <NUM> extend into the intermediate region <NUM> on the lateral and medial sides <NUM>, <NUM> of the interior chamber <NUM>.

The posterior lobe <NUM> extends from a first end <NUM> connected to the second end 156i of the lateral anterior lobe 152i in the intermediate region <NUM> on the lateral side <NUM>, to a second end <NUM> connected to the second end 156j of the medial anterior lobe 152j in the intermediate region on the medial side <NUM>. Thus, the posterior lobe <NUM> extends continuously around the posterior end <NUM> from the lateral side <NUM> of the bladder 106b to the medial side <NUM> of the bladder 106b. In the illustrated example, the intermediate portion <NUM> of the posterior lobe may include a substantially constant cross-sectional area from the first end <NUM> to the second end <NUM>.

As shown in <FIG>, the variable cross section of the peripheral chamber 132b results in the overall width W106b of the bladder 106b being variable from the anterior end <NUM> to the posterior end <NUM>. Particularly, the bladder 106b has a first width W106b-<NUM> across the intermediate portions 158i, 158j of the anterior lobes 152i, 152j adjacent to the anterior end <NUM>, a second width W106b-<NUM> across the second ends 156i, 156j of the anterior lobes 152i, 152j in the intermediate region <NUM>, and a third width W106b-<NUM> across the intermediate portion <NUM> of the posterior lobe <NUM> adjacent to the first and second ends <NUM>, <NUM>. Here, the second width W106b-<NUM> is less than the first width W106b-<NUM> and the third width W106b-<NUM>, while the third width W106b-<NUM> is greater than the first width W106b-<NUM> and the second width W106b-<NUM>.

Claim 1:
A bladder (<NUM>) for an article of footwear (<NUM>), the bladder (<NUM>) extending from an anterior end (<NUM>) to a posterior end (<NUM>) and comprising:
a first chamber (<NUM>) disposed in an interior region (<NUM>) of the bladder (<NUM>) and including a first interior void (<NUM>) having a first pressure;
a second chamber (<NUM>) completely surrounding the first chamber (<NUM>) and including a second interior void (<NUM>) having a second pressure different than the first pressure, and
a web area (<NUM>) disposed between and connecting the first chamber (<NUM>) and the second chamber (<NUM>), the web area (<NUM>) maintaining an arcuate shape about an entire perimeter of the first chamber (<NUM>).