Patent Publication Number: US-2020288813-A1

Title: Articles of footwear with upper incorporating chamber element

Description:
BACKGROUND 
     Improvements in footwear technology may have benefits for a variety of activities. Footwear design may benefit wearers for purposes of ordinary, day-to-day use. Footwear design may also benefit wearers who work in physically challenging conditions requiring bodily protection, or engage in recreational outdoor activities such as hiking or fishing. Some improvements in footwear technology may be advantageous to generally athletic activities such as running, or to specific sports, such as football, baseball, basketball, hockey, soccer, tennis, golf, lacrosse, or cricket. 
     An article of footwear may in turn have various parts subject to improvement. For example, a conventional article of footwear may include an upper and a sole structure. The upper may be formed from one or more of a variety of material elements (e.g. textiles, leather, synthetic leather, and foam materials), and may define a void that securely receives the foot of a wearer and positions it with respect to the sole structure. The sole structure may be secured to a lower surface of the upper, and may have a layered configuration that includes a comfort-enhancing insole, a resilient midsole formed from a polymer foam, and a ground-contacting outsole. 
     A polymer foam material within a sole structure may include a plurality of open or closed cells that deteriorate following repeated compressions. The effects of this deterioration may be decreased by incorporating a fluid-filled chamber into the sole structure. The chamber may be formed from a polymer material that is sealed to enclose a fluid, and may be encapsulated within the polymer material, or may be located above or below it, or may form any portion of the midsole. Fluid-filled chambers suitable for such footwear applications may be manufactured by thermoforming techniques. 
     The sole structure may serve to attenuate ground reaction forces, to provide traction, and to control various foot motions such as pronation. The upper and the sole structure may cooperatively provide a comfortable structure to benefit a wearer engaged in any of a variety of activities. 
     Meanwhile, an individual wearing an article of footwear and engaged in an athletic activity or sport may make sudden stops or changes of direction, which may subject the upper of the footwear to various deforming forces. For example, an individual playing a game of football or basketball may need to rapidly change direction to avoid another player. Such movements may subject an article of footwear to various deforming forces, and may also subject an ankle of the individual to various stresses. 
     At the same time, an individual may be a member of a team, or may be one individual competitor among many individual competitors. Whether as an individual competitor or a part of a team, the individual may benefit from an increased ability to identify themselves. Identification may help team-mates locate an individual playing on a field, for example, to the benefit of the team during the game. Similarly, individual players may also benefit from being made more easily recognizable to referees, coaching staff, or others. 
     Therefore, there exists a need in the footwear art for improvements that may mitigate various deforming forces to which an article of footwear may be subjected and various stressing forces to which an ankle of an individual may be subjected. There also exists a need for improvements that may help to identify an individual wearing the article of footwear. 
     SUMMARY 
     Uppers for articles of footwear that include chamber elements are described below. Including a fluid-filled chamber within the structure of the footwear upper provides an added degree of comfort, cushioning, fit and support to the wearer&#39;s foot. For example, in activities that require sudden stop-and-go-movements or lateral cutting movements, an upper having a chamber that surrounds the Achilles tendon area of the heel and ankle could provide added stability, support and recovery from a stretched or angled position of the foot. Meanwhile, the incorporation of one or more colors into exposed portions of a fluid-filled chamber within a footwear upper expands the potential aesthetic qualities of the footwear as well as increasing the footwear&#39;s potential value as identification or insignia. Footwear and uppers incorporating such chambers may therefore mitigate deforming forces or stressing forces, or assist in personalizing or customizing an article of footwear, or both. 
     In one aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer and comprises an outer layer, an inner layer, and a chamber element. The outer layer forms part of an exterior surface of the article of footwear and has at least one aperture positioned in a rearfoot region of the footwear. The inner layer is attached to the outer layer and is positioned adjacent the interior void to form part of an interior surface of the footwear. The chamber element is sealed to enclose a fluid and is positioned at least partially between the outer layer and the inner layer. The chamber element has at least a portion that protrudes at least partially through the aperture. 
     In another aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer and comprises an outer layer, an inner layer, and a sealed fluid-filled chamber element. The outer layer forms part of an exterior surface of the footwear and has at least one aperture. The inner layer is positioned opposite the outer layer and forms part of an interior surface of the footwear. The sealed fluid-filled chamber element includes a first barrier layer and a second barrier layer and is positioned at least partially between the outer layer and the inner layer. The chamber element includes a subchamber protruding at least partially through the aperture to form part of the exterior surface. The subchamber is at least partially formed from a colored material. 
     In yet another aspect, the invention provides an upper of an article of footwear that comprises an outer layer and a sealed fluid-filled chamber element. The outer layer forms part of an exterior surface of the footwear. The chamber element is positioned to contact the outer layer and surrounds a heel region of the footwear. The chamber element has a protrusion extending rearward through an aperture in the outer layer to form part of the exterior surface. The protrusion includes a colored material. 
     In a further aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer and comprises an outer layer, an inner layer, and a fluid-filled chamber. The outer layer forms part of an exterior surface of the footwear and has a plurality of apertures. At least one of the apertures is positioned at a rearward-facing portion of a heel region of the footwear. The inner layer is positioned adjacent the interior void and forms part of an interior surface of the footwear. The fluid-filled chamber element is positioned at least partially between the outer layer and the inner layer. The chamber element includes an interior bond and a plurality of subchambers. The interior bond is positioned on one of a lateral side of the upper and a medial side of the upper. The plurality of subchambers is positioned adjacent to at least fifty percent of a periphery of the interior bond. The subchambers are in fluid communication with each other, and each of the subchambers protrudes at least partially through one of the apertures. 
     In another aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer and comprises an outer layer, an inner layer, and a fluid-filled chamber element. The outer layer forms part of an exterior surface of the footwear and has a plurality of apertures. At least one of the apertures is positioned at a rearward-facing portion of a heel region of the footwear. The inner layer is positioned adjacent the interior void and forms part of an interior surface of the footwear. The fluid-filled chamber element is at least partially formed from a transparent colored polymer material and is positioned at least partially between the outer layer and the inner layer. The chamber element includes a heel subchamber, a plurality of lateral subchambers, a plurality of medial subchambers, a lateral internal bond, and a medial internal bond. The heel subchamber and the plurality of lateral subchambers are adjacent to at least fifty percent of a periphery of the lateral internal bond, and the heel subchamber and the plurality of medial subchambers are adjacent to at least fifty percent of a periphery of the medial internal bond. 
     In yet another aspect, the invention provides an article of footwear having an upper and a sole structure. The upper includes an exterior surface facing outward from the footwear and an interior surface defining an interior void for receiving a foot of a wearer. The upper comprises a chamber element sealed to enclose a fluid, the chamber element surrounding a heel region of the footwear and forming at least  80  percent of the exterior surface of the upper in the heel region. 
     In a further aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer. The upper comprises a material layer and a fluid-filled chamber element. The material layer has a forward portion that forms part of an exterior surface of the upper in a forefoot region of the footwear. The fluid-filled chamber element forms part of the exterior surface of the upper in both a midfoot region of the footwear and a heel region of the footwear. The chamber element has a first barrier layer and a second barrier layer that define a plurality of subchambers. Each subchamber is exposed to an exterior of the footwear and is at least partially formed from a colored material. 
     In another aspect, the invention provides an article of footwear having an upper and a sole structure. The upper defines an interior void for receiving a foot of a wearer. The upper comprises a material layer and a fluid-filled chamber element. The material layer has a forward portion defining the interior void in a forefoot region of the footwear and a rearward portion defining the interior void in both a midfoot region of the footwear and a heel region of the footwear. The fluid-filled chamber element is secured to an outer surface of the rearward portion of the material layer. The chamber element includes a plurality of subchambers. The chamber element is at least partially formed from a transparent colored polymer material. 
     Other systems, methods, features and advantages of the invention will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the invention, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  is a lateral side elevational view of an article of footwear having an upper incorporating a chamber element. 
         FIG. 2  is a medial side elevational view of the article of footwear. 
         FIG. 3  is a rear elevational view of the article of footwear. 
         FIG. 4  is a perspective view of the article of footwear. 
         FIGS. 5A-5C  are cross-sectional views of the article of footwear, as defined by section lines  6 A through  6 C in  FIG. 3 . 
         FIG. 6  is a perspective view of the chamber element. 
         FIG. 7  is a top plan view of the chamber element. 
         FIG. 8  is a cross-sectional view of the chamber element, as defined by section line  8  in  FIG. 7 . 
         FIG. 9  is a lateral side elevational view of a foot of a wearer. 
         FIG. 10  is a lateral side elevational view of a second embodiment of the article of footwear having an upper incorporating a chamber element. 
         FIG. 11  is a rear elevational view of the article of footwear of  FIG. 10 . 
         FIG. 12  is a perspective view of the article of footwear of  FIG. 10 . 
         FIGS. 13A-13B  are cross-sectional views of the article of footwear of  FIG. 10 , as defined by section lines  13 A and  13 B in  FIG. 11 . 
         FIG. 14  is a perspective view of the chamber element of  FIG. 10 . 
         FIG. 15  is a top plan view of the chamber element of  FIG. 10 . 
         FIG. 16  is a lateral side elevational view of a third embodiment of the article of footwear having an upper incorporating a chamber element. 
         FIG. 17  is a rear elevational view of the article of footwear of  FIG. 16 . 
         FIG. 18A-18B  are cross-sectional views of the article of footwear of  FIG. 16 , as defined by section lines  18 A and  18 B in  FIG. 17 . 
         FIG. 19  is a lateral side elevational view of a fourth embodiment of the article of footwear having an upper incorporating a chamber element. 
         FIG. 20  is a rear elevational view of the article of footwear of  FIG. 19 . 
         FIG. 21  is a perspective view of the article of footwear of  FIG. 19 . 
         FIG. 22  is a side elevational view of the chamber element of  FIG. 19 . 
         FIG. 23  is a top plan view of the chamber element of  FIG. 19 . 
         FIG. 24  is a top plan view corresponding with  FIG. 7  and depicting a further configuration of the chamber element. 
         FIGS. 25A-25B  are cross-sectional views corresponding with  FIG. 8  and depicting further configurations of the chamber element. 
         FIGS. 26A-26B  are cross-sectional views corresponding with  FIG. 6B  and depicting further configurations of the chamber element. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion and accompanying figures disclose various configurations of uppers and chamber elements with reference to footwear having a configuration that is suitable for an athletic activity or sport in which a participant may make sudden stops or changes of direction, such as football, basketball, tennis, or soccer. However, concepts associated with the uppers and chamber elements may be applied to a wide range of athletic or sport-related footwear styles, including casual footwear, walking shoes, golf shoes, cross-training shoes, hiking shoes and boots, and ski and snowboarding boots, for example. Associated concepts may also be utilized with footwear styles that are generally considered to be non-athletic, including dress shoes and loafers. Accordingly, uppers and chamber elements incorporating the concepts disclosed herein may be utilized within a variety of articles of footwear. 
     General Footwear Structure 
     An article of footwear  10  is depicted in  FIGS. 1-5C  as including an upper  20  for receiving a foot of a wearer and a sole structure  50 . For reference purposes, footwear  10  may be divided into three general regions: a forefoot region  11 , a midfoot region  12 , and a heel region  13 , as shown in  FIGS. 1 and 2 . Footwear  10  also includes a lateral side  14  and a medial side  15 . Forefoot region  11  generally includes portions of footwear  10  corresponding with the toes and the joints connecting the metatarsals with the phalanges. Midfoot region  12  generally includes portions of footwear  10  corresponding with the arch area of the foot, and heel region  13  corresponds with rear portions of the foot, including the calcaneus bone. Lateral side  14  and medial side  15  extend through each of regions  11 - 13  and correspond with opposite sides of footwear  10 . Regions  11 - 13  and sides  14 - 15  are not intended to demarcate precise areas of footwear  10 . Rather, regions  11 - 13  and sides  14 - 15  are intended to represent general areas of footwear  10  to aid in the following discussion. In addition to footwear  10 , regions  11 - 13  and sides  14 - 15  may also be applied to upper  20 , sole structure  50 , and individual elements thereof, such as chamber element  24 . 
     Upper  20  is depicted as having a substantially conventional configuration incorporating a plurality of material elements (e.g., textile, foam, leather, and synthetic leather) that are stitched, adhered, bonded, or otherwise joined together to form an interior void for securely and comfortably receiving a wearer&#39;s foot. The material elements may be selected and located with respect to upper  20  in order to selectively impart properties of durability, air-permeability, wear-resistance, flexibility, and comfort, for example. An opening  21  in heel region  13  provides access to the interior void. 
     Upper  20  includes a lace element  22  that is utilized in a conventional manner to modify the dimensions of the interior void, thereby securing the foot within the interior void and facilitating entry and removal of the foot from the interior void. Lace element  22  may extend through apertures in upper  20 , and a tongue portion  23  of upper  20  may extend between the interior void and lace element  22 . However, in some configurations, footwear  10  may incorporate other structures that function as lace element  22 . Upper  20  incorporates a sealed fluid-filled chamber element  24 . Upper  20  may also incorporate a sockliner adjacent a plantar (i.e., lower) surface of the foot to enhance the comfort of footwear  10 . 
     Sole structure  50  is secured to upper  20  and has a configuration that extends between upper  20  and the ground, and thus effectively extends between the foot and the ground. Sole structure  50  may include a midsole formed from a polymer foam material, such as polyurethane or ethylvinylacetate, and sole structure  50  may also incorporate one or more additional footwear elements that enhance the comfort, performance, or ground reaction force attenuation properties of footwear  10 , including fluid-filled chambers, plates, moderators, lasting elements, or motion control members. Sole structure  50  may also include an outsole secured to a lower surface of the midsole. The outsole may be formed from a material that provides a durable and wear-resistant surface for engaging the ground, and may be textured to enhance the traction (i.e., friction) properties between footwear  10  and the ground, such as rubber materials. In addition to attenuating ground reaction forces, i.e., providing cushioning for the foot, sole structure  50  may provide traction, impart stability, and limit various foot motions, such as pronation. 
     Given that various aspects of the present application primarily relate to upper  20 , sole structure  50  may exhibit the general configuration discussed above or the general configuration of practically any other conventional or non-conventional sole structure. As a result, the overall configuration of sole structure  50  may vary significantly. 
     First Upper and Chamber Element Configuration 
       FIGS. 1-8  depict a first configuration of footwear  10  and an upper and chamber element incorporated therein. As incorporated into footwear  10  and illustrated in  FIGS. 1-5C , chamber element  24  has a shape that surrounds a rearfoot region or heel region  13  of footwear  10 . That is, chamber element  24  extends from lateral side  14  of footwear  10 , around heel region  13 , and into medial side  15  of footwear  10 . Chamber element  24  is depicted as extending beyond heel region  13  toward forefoot region  11  and into midfoot region  12  (that is, in a forefoot direction of footwear  10 ). However, in some configurations chamber element  24  may extend beyond midfoot region  12  and into forefoot region  11 , while in other configurations chamber element  24  may not extend into midfoot region  12 . 
     When upper  20  receives the foot, chamber element  24  may extend around an ankle area of the foot. More particularly, with reference to  FIG. 9 , chamber element  24  may extend around an Achilles tendon area  110  of the foot. Chamber element  24  may also extend around portions of a tarsus area  120  of the foot, more particularly a calcaneus bone area  122 , a talus area  124 , a distal tibia area  126 , and a distal fibula area  128 . As a result, chamber element  24  may extend around portions of the foot corresponding with various joints of the ankle, such as the talocrural joint (between the tibia, the fibula, and the talus), the subtalar joint (between the talus and the calcaneus bone), and the distal or inferior tibiofibular joint (between the distal ends of the tibia and the fibula). Chamber element  24  may similarly extend around portions of the foot corresponding with various ligaments of the ankle, such as the deltoid ligament, the anterior talofibular ligament, the posterior talofibular ligament, and the calcaneofibular ligament. 
     Upper  20  is depicted in  FIGS. 5A-5C  as having an inner layer  26  and an opposite outer layer  27 . Inner layer  26  is positioned adjacent the interior void and forms part of an interior surface of footwear  10 , while outer layer  27  forms part of an exterior surface of footwear  10 . Each of layers  26  and  27  incorporates one or more material elements (e.g. textiles, leather, synthetic leather, and foam materials) that are stitched, adhered, bonded, or otherwise joined together or attached. 
     Chamber element  24  is situated between inner layer  26  and outer layer  27 . Chamber element  24  is, accordingly, positioned to contact and be flush against inner surfaces of layers  26  and  27  in a sandwich configuration. However, portions of chamber element  24  may be exposed through outer layer  27  to an exterior of footwear  10 . 
     More particularly, outer layer  27  includes a plurality of apertures through which portions of chamber element  24  are exposed. A rear aperture  34  is positioned at a rearward-facing portion of heel region  13 , or in a rearfoot region of footwear  10 . Additionally, a plurality of laterally-facing apertures are positioned on a lateral side of outer layer  27 , while a corresponding plurality of medially-facing apertures are positioned on a medial side of outer layer  27 , opposite the laterally-facing apertures. Specifically, both lateral side  14  and medial side  15  include a top aperture  31 , a bottom aperture  32 , and two front apertures  33 . Of these apertures, front apertures  33  are substantially located in midfoot region  12 , while rear aperture  34 , top apertures  31 , and bottom apertures  32  are substantially located in heel region  13 . 
     As depicted, various portions of chamber element  24  are exposed through apertures  31 - 34 . In some alternate configurations, however, portions of chamber element  24  may be exposed to an interior of footwear  10 , or may be otherwise not covered by inner layer  26 . Nevertheless, while some portions of chamber element  24  may be exposed to an exterior of footwear  10 , or to an interior of footwear  10 , or both, other portions of chamber element  24  are at least partially positioned between inner layer  26  and outer layer  27  of upper  20 . 
     As depicted individually in  FIGS. 6-8 , chamber element  24  is formed from a first barrier layer  28  and an opposite second barrier layer  29 . Each of barrier layers  28  and  29  is in turn formed from a polymer material. Barrier layers  28  and  29  define a plurality of subchambers in chamber element  24  and provide a durable sealed barrier for retaining a pressurized fluid  25  within the subchambers. More particularly, chamber element  24  includes a rear subchamber  44 , and also includes a top subchamber  41 , a bottom subchamber  42 , and a front subchamber  43  on both lateral side  14  and medial side  15 . Accordingly, subchamber  44  is a heel subchamber, while subchambers  42 - 44  on lateral side  14  are lateral subchambers and subchambers  42 - 44  on medial side  15  are medial subchambers. 
     An interior bond  45  is also defined on both lateral side  14  and medial side  15  of chamber element  24 , positioned between subchambers  41 - 44 , and adjacent to interior peripheries or inner peripheries of a plurality of subchambers  41 - 44 . As depicted, subchambers  41 - 44  on each side are adjacent to at least fifty percent of a periphery of the corresponding interior bond  45 . Each interior bond extends across at least twenty percent of an area of chamber element  24 , at least fifty percent of a height of chamber element  24 , and at least twenty-five percent of a width of chamber element  24 . 
     In various other configurations, subchambers  41 - 44  may be adjacent to more of a periphery of interior bond  45 . For example, subchambers  41 - 44  may be adjacent to between fifty and eighty percent of a periphery of interior bond  45 . Similarly, in various configurations, interior bonds  45  may extend across more of chamber element  24 , such as between twenty and thirty percent of an area of chamber element  24 , or between fifty and eighty percent of a height of chamber element  24 , or between twenty-five and forty percent of a width of chamber element  24 . 
     Accordingly, outer layer  27  defines a plurality of apertures, and chamber element  24  defines a plurality of corresponding subchambers. Returning to  FIGS. 1-5C , subchambers  41 - 44  of chamber element  24  protrude at least partially through apertures  31 - 34  of outer layer  27 , respectively. Portions of subchambers  41 - 44  thus form parts of an exterior surface of footwear  10 . 
     Furthermore, due to the position of chamber element  24  in upper  20 , subchambers  41 - 44  protrude through apertures  31 - 34  in various directions, as depicted in  FIGS. 1-5C . Subchamber  44 , for example, is positioned at a rearward-facing portion of heel region  13  and protrudes in a rearward direction through aperture  34  of outer layer  27 . In a similar manner, subchambers  41 - 43  positioned on lateral side  14  protrude outward in a lateral direction through corresponding apertures  31 - 33  on lateral side  14 , while subchambers  41 - 43  positioned on medial side  15  protrude outward in a medial direction through corresponding apertures  31 - 33  on medial side  15 . 
     Subchambers  41 - 44  are formed in various positions on chamber element  24 . Rear subchamber  44 , top subchambers  41 , and bottom subchambers  42  are substantially located in heel region  13 , while front subchambers  43  are substantially located in midfoot region  12 . Rear subchamber  44  and top subchambers  41  are formed to have elongate rectangular configurations, while bottom subchambers  42  and front subchambers  43  are formed to have triangular configurations. 
     Subchambers  41 - 44  are thus formed and shaped, and are positioned in various areas of footwear  10 , to correspond with various areas of the foot. Rear subchamber  44  is positioned to the rear of an area of footwear  10  extending around Achilles tendon area  110  of the foot, while portions of subchambers  42  are positioned in areas of footwear  10  extending around lateral and medial sides of Achilles tendon area  110  of the foot. Similarly, top subchambers  41  are positioned in areas of footwear  10  near the talus of the foot (i.e., the uppermost tarsal bone) and the distal ends of the tibia and the fibula; front subchambers  43  are positioned in areas of footwear  10  near anterior portions (i.e., front portions) of the talus and the calcaneus; and portions of subchambers  42  are positioned in areas of footwear  10  near posterior portions (i.e., back portions) of the talus and the calcaneus. That is, subchambers  41 - 43  are positioned on lateral and medial sides of tarsus area  120  of the foot. 
     An advantage of subchambers  41 - 44 , and of interior bonds  45  positioned between subchambers  41 - 44 , is that a stability of footwear  10  may be increased in positions corresponding with various areas of the foot, such as (a) around the Achilles tendon and (b) around the bones, joints, and ligaments of the ankle. At the same time, subchambers  41 - 44  may enhance a cushioning of footwear  10 , and may also enhance a fit of an interior surface of footwear  10  against the foot of a wearer. That is, subchambers  41 - 44  and interior bonds  45  may make chamber element  24  more resistant to deforming or stressing forces, which may in turn improve the stability of footwear  10 , while subchambers  41 - 44  may also improve the cushioning of footwear  10  and its capacity to conform to a wearer&#39;s foot. 
     In manufacturing chamber element  24 , a pair of polymer sheets may be molded during a thermoforming process to define barrier layers  28  and  29 . The thermoforming process may impart differing thicknesses to barrier layers  28  and  29  in different areas of chamber element  24 . For example, barrier layer  28  or barrier layer  29  may have a first thickness at interior bonds  45 , or at other areas of chamber element  24  where the two barrier layers are bonded together, and a second, lesser thickness at one of subchambers  41 - 44 . Accordingly, barrier layers  28  and  29  may be thinner at subchambers  41 - 44  than at interior bond  45 . 
     As depicted, barrier layers  28  and  29  are formed from a transparent colored polymer material, through which light may pass without being scattered. Barrier layers  28  and  29  are, therefore, colored and see-through. In some configurations, however, barrier layers  28  and  29  may be formed from a non-transparent colored material. For example, barrier layers  28  and  29  may be formed from a translucent colored material, through which light may pass while being scattered, or an opaque colored material, through which light may not pass. 
     Moreover, in some configurations, one layer of barrier layers  28  and  29  may be formed from a colored polymer material, while the other layer is formed from a non-colored polymer material. For example, first barrier layer  28  may be made of a transparent colored polymer material, and second barrier layer  29  may be made of a non-colored polymer material (which may be transparent, translucent, or opaque). Alternatively, first barrier layer  28  may be made of a transparent polymer material that is not colored, while second barrier layer  29  may be made of a colored polymer material. Accordingly, when such configurations of chamber element  24  are incorporated into footwear  10 , second barrier layer  29  may be seen through the transparent material of first barrier layer  28 , and may thereby be exposed through both first barrier layer  28  and various apertures in outer layer  27 . 
     Some configurations of chamber element  24  may incorporate more than one colored material. As one example, each of barrier layers  28  and  29  may be formed of a different colored polymer material (one red and one blue, for example). In other configurations, either or both of barrier layers  28  and  29  may be formed from a material having multiple colors, or from multiple materials each having a color. Some configurations may incorporate a material having multiple colors in a pattern, or multiple colors comprising a graphical element or indicia. 
     In other configurations, a transparent colored material may be incorporated into one or more of barrier layers  28  and  29 , but either the color of the material, or the transparency of the material, or both may extend only throughout a portion of barrier layers  28  and  29 . For example, second barrier layer  29  may be partially formed from a transparent colored material, so that a corresponding portion of second barrier layer  29  subsequently exposed through an aperture in outer layer  27  of footwear  10  is transparent and colored, while other portions may be non-transparent or non-colored. Barrier layers  28  and  29 , and subchambers  41 - 44 , may accordingly be at least partially formed from a colored polymer material 
     By incorporating materials having one or more colors into chamber element  24 , and by incorporating one or more apertures into outer layer  27 , footwear  10  may advantageously facilitate the identification of a wearer. In various configurations, if at least one of barrier layers  28  and  29  incorporates a color, an on-looking viewer may be able to see and interpret that color—and, in turn, footwear  10 —as being associated with a particular individual, for example, or as being associated with a particular team or organization. Moreover, since portions of subchambers  41 - 44  protruding through apertures  31 - 34  may be seen even from highly oblique angles, a colored polymer material of subchambers  41 - 44  may assist an on-looking viewer in identifying footwear  10  as being associated with an individual or team even when subchambers  41 - 44  are viewed at highly oblique angles, such as from a position in front of or behind footwear  10 . The incorporation of colored polymer materials into chamber element  24  may accordingly help to identify or otherwise differentiate an individual wearing footwear  10 . Enabling different color combinations, along with the possibility of varying the shapes, sizes and positions of apertures in outer layer  27 , provides much more design freedom for aesthetics as well as identifying symbols and colors. 
     The thermoforming process used to mold the pair of polymer sheets and define barrier layers  28  and  29  serves to (a) impart shape to portions of the polymer sheets to define subchambers  41 - 44  of chamber element  24  and (b) form bonded portions of chamber element  24  around and between subchambers  41 - 44 . These bonded portions include a portion extending around a periphery of chamber element  24 , as well as interior bonds  45  on each side of chamber element  24 . 
     In some configurations, an inflation conduit leading to one or more of subchambers  41 - 44  may be formed in chamber element  24 , as well as one or more internal conduits, and subchambers  41 - 44  may be in fluid communication with each other through the internal conduits. However, in other configurations, subchambers  41 - 44  may not be in fluid communication with each other, and may be separately pressurized or inflated. Following the thermoforming process, a fluid  25  such as air or nitrogen may be injected into through the inflation conduit, and from there into the internal conduits and subchambers  41 - 44 . Fluid  25  may then be pressurized to between zero and three-hundred-fifty kilopascals (i.e., approximately fifty-one pounds per square inch) or more, and the polymer sheets may be bonded or joined together to form a seal that prevents fluid  25  from escaping. In various configurations, a thermoforming process or other process may accordingly be used to bond portions of barrier layers  28  and  29  together, and seal barrier layers  28  and  29  to enclose fluid  25  in subchambers  41 - 44 . 
     A wide range of polymer materials may be utilized for layers  28  and  29 . In selecting a material for layers  28  and  29 , engineering properties of the material (e.g., tensile strength, stretch properties, fatigue characteristics, dynamic modulus, and loss tangent) as well as the ability of the material to prevent the diffusion of the fluid contained by layers  28  and  29  may be considered. When formed of thermoplastic urethane, for example, layers  28  and  29  may have a thickness of approximately 1.0 millimeter, but the thickness may range from 0.25 to 2.0 millimeters or more, for example. In addition to thermoplastic urethane, examples of polymer materials that may be suitable for chamber  33  include polyurethane, polyester, polyester polyurethane, and polyether polyurethane. Layers  28  and  29  may also be formed from a material that includes alternating layers of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer, as disclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell, et al, the entire disclosures of which are hereby incorporated by reference. A variation upon this material may also be utilized, wherein a center layer is formed of ethylene-vinyl alcohol copolymer, layers adjacent to the center layer are formed of thermoplastic polyurethane, and outer layers are formed of a regrind material of thermoplastic polyurethane and ethylene-vinyl alcohol copolymer. Another suitable material for layers  28  and  29  is a flexible microlayer membrane that includes alternating layers of a gas barrier material and an elastomeric material, as disclosed in U.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk, et al. Further suitable materials include polyurethane including a polyester polyol, as disclosed in U.S. Pat. Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk, et al, the entire disclosures of which are hereby incorporated by reference. 
     In some configurations of footwear  10 , fluid  25  may be any of a variety of fluids, such as a gas, a liquid such as water, a gel material, or another non-gaseous fluid. With regard to gasses, chamber element  24  (and subchambers  41 - 44 ) may enclose air, nitrogen, octafluorapropane, hexafluoroethane, or sulfur hexafluoride, for example. Fluid  25  may also be a colored substance, such as a colored liquid, or a colored gel material, or a colored gas. Meanwhile, barrier layers  28  and  29  may be formed of a transparent, non-colored polymer material, while fluid  25  of footwear  10  may be a colored liquid or a colored gel. Fluid  25  may accordingly be exposed seen through the transparent material of first barrier layer  28 , and may thereby be exposed through both first barrier layer  28  and various apertures in outer layer  27 . 
     Although chamber element  24  is discussed above and depicted as being sealed, in some configurations, chamber element  24  may be a component of a fluid system within footwear  10 . For example, pumps, conduits, and valves may be joined with chamber element  24  to provide a fluid system that pressurizes chamber element  24  with air from the exterior of footwear  10 . More particularly, chamber element  24  may be utilized in combination with any of the fluid systems disclosed in U.S. Pat. No. 7,210,249 to Passke, et al. and U.S. Pat. No. 7,409,779 to Dojan, et al. 
     Second Upper and Chamber Element Configuration 
       FIGS. 10-15  depict a second configuration footwear  10  and an upper and chamber element incorporated therein. As depicted, footwear  10  includes upper  20  defining an interior void for receiving a foot of the wearer and sole structure  50  extending between the foot and the ground. Upper  20  in turn includes a material element  56  positioned adjacent to the interior void and a chamber element  54 . 
     Chamber element  54  extends across and is secured to an outer surface of material element  56  in midfoot region  12  and heel region  13  of footwear  10 . More particularly, chamber element  54  extends from midfoot region  12  on lateral side  14 , around heel region  13 , and into midfoot region  12  on medial side  15 . Accordingly, a forward portion  53  of material element  56  forms part of an exterior surface of upper  20  in forefoot region  11 , while chamber element  54  forms part of the exterior surface of upper  20  in midfoot region  12  and heel region  13 . Forward portion  53  is depicted as extending from lateral side  14  to medial side  15  in forefoot region  11 . Forward portion  53  of material layer  56  may accordingly define the interior void in forefoot region  11 , while a rearward portion of material layer  56  may define the interior void in midfoot region  12  and heel region  13 . 
     Chamber element  54  includes a first barrier layer  58  and a second barrier layer  59  that define a plurality of subchambers, which are sealed to enclose and retain a pressurized fluid  55 . Chamber element  54  is accordingly formed to include a plurality of subchambers extending outward from footwear  10 . 
     In general, chamber element  54  may include any of a variety of configurations of subchambers, such as those described above with respect to  FIGS. 1-8 . As depicted in  FIGS. 10-15 , chamber element  54  includes top subchambers  71 , bottom subchambers  72 , front subchambers  73 , and rear subchamber  74 . Chamber element  54  is also depicted as defining internal conduits  88 , and subchambers  71 - 74  are in fluid communication with each other through internal conduits  88 . In other configurations of chamber element  54 , however, one or more internal conduits  88  may be absent, and one or more subchambers  71 - 74  may be sealed to enclose fluid  55  therein. 
     Barrier layers  58  and  59  of chamber element  54  are bonded at bonded areas  75 , which extend around and between subchambers  71 - 74  and internal conduits  88 . Bonded areas  75  of chamber element  24  thus define the various peripheral shapes of subchambers  71 - 74  and internal conduits  88 . 
     A peripheral bond  90  extends around an outer periphery of chamber element  54  and, in turn, around subchambers  71 - 74 . Peripheral bond  90  includes a plurality of eyelets  91  adjacent to front subchambers  73 . Lace  22  may be threaded through eyelets  91  in addition to other parts of upper  20  adjacent to tongue portion  23 . However, some configurations of chamber element  54  may not include eyelets  91 . 
     Peripheral bond  90  also includes a plurality of flaps  93  separated by a plurality of notches  95 . Due to the configuration of notches  95  along peripheral bond  90 , when chamber element  54  is bent around heel region  13  of footwear  10 , flaps  93  may be bent inward and upward without obstructing each other. A lower and outer surface of flaps  93  may then be secured to the midsole of sole structure  50  in the course of incorporating chamber element  54  into upper  20 . 
     As depicted, chamber element  54  also includes an inflation conduit  87 . In one exemplary manufacturing process, two polymer sheets may be thermoformed to form barrier layers  58  and  59 , which in turn include bonded areas  75 , peripheral bond  90 , and inflation conduit  87 . Bonded areas  75  may define subchambers  71 - 74 , as well as internal conduits  88 . Following the thermoforming process, a fluid  55  (which may be a gas, such as air or nitrogen) is injected through inflation conduit  87 , and from there into internal conduits  88  and subchambers  71 - 74 . Fluid  55  may then be pressurized to between zero and three-hundred-fifty kilopascals (i.e., approximately fifty-one pounds per square inch) or more, and inflation conduit  87  may be sealed to prevent fluid  55  from escaping. Once sealed, inflation conduit  87  may advantageously serve as a pull-tab, to assist a wearer in donning footwear  10 . 
     On some configurations, one or both of the polymer sheets may also incorporate strands of material. For example, the polymer sheet used to form first barrier layer  58  may incorporate a first set of parallel strands of material running in a first direction and a second set of parallel strands of material running in a second direction. In such configurations, the strands of the first set may be joined to the strands of the second set where they overlap to form a net or a web of material strands. The incorporation of parallel strands of material (or a net or web of material strands) into first barrier layer  58  may advantageously restrict an outward expansion of barrier layer  58  upon pressurization of chamber element  54 . 
     As depicted, chamber element  54  surrounds a rearfoot region of footwear  10 , extending from lateral side  14  to medial side  15  and around heel region  13 , and forms at least  95  percent of an exterior surface of upper  20  in both midfoot region  12  and heel region  13 . In other configurations, chamber element  54  may form at least  80  percent of an exterior surface of upper  20  in regions  12  and  13 . The extent of chamber element  54 , and the positioning of subchambers  72 - 74  on chamber element  54 , may advantageously stabilize various portions of footwear  10 , such as (a) portions around the Achilles tendon, and (b) portions around the bones, joints, and ligaments of the ankle. Chamber element  54  and subchambers  71 - 74  may also enhance cushioning properties of upper  20  and of footwear  10 , and may enhance a fit of footwear  10  against the foot of a wearer. 
     Meanwhile, barrier layers  58  and  59  may be formed to include materials similar to those discussed above with respect to  FIGS. 1-8 . For example, either or both of layers  58  and  59  may be formed from a transparent colored polymer material. Alternatively, chamber element  54 , and subchambers  71 - 74 , may be at least partially formed from a colored material, or may include colored portions. 
     By incorporating one or more colored materials into chamber element  54 , footwear  10  may advantageously facilitate the identification of a wearer, either as a particular individual, or as being associated with a particular team or organization. Moreover, by protruding outward from footwear  10 , subchambers  71 - 74  may facilitate the identification of a wearer even when viewed at highly oblique angles (such as when viewed from the front or the rear of the wearer). Meanwhile, material element  56  may also incorporate materials of various colors, including not only white materials, but materials of other colors. One or more colors of material element  56  may thus combine with one or more colors of barrier layers  58  and  59  to generate specific colors and patterns of color as viewed from the exterior of footwear  10 . 
     Chamber element  54  is depicted in  FIGS. 10-13B  as being positioned adjacent to an outer surface of material element  56  and as forming part of an exterior surface of upper  20  in both midfoot region  12  and heel region  13  of footwear  10 . However, other configurations of material element  56  and chamber element  54  are possible. 
     In some alternate configurations, for example, material element  56  may have both an inner portion and an outer portion, and the outer portion may be substantially absent from portions heel region  13 , or from portions of both midfoot region  12  and heel region  13 . Accordingly, the outer portion of material layer  56  may include an aperture exposing the inner portion of material layer  56  in heel region  13 , or in both heel region  13  and midfoot region  12 . In such configurations, part of peripheral bond  90  may be positioned between the inner portion of material element  56  and the outer portion of material element  56 . 
     In other alternate configurations, material layer  56  may be substantially absent from heel region  13 , or from heel region  13  and portions of midfoot region  12 . In such configurations, part of peripheral bond  90  may be secured to an inner surface or an outer surface of material layer  56 . Chamber element  54  may then form at least  80  percent of an exterior surface of upper  20  in midfoot region  12  and heel region  13 . In such configurations, chamber element  54  may also include a backing material applied to at least part of its inner surface, which may advantageously modify the tactile properties of the inner surface, for the wearer&#39;s comfort. 
     Third Upper and Chamber Element Configuration 
       FIGS. 16-18B  depict a third configuration of footwear  10  and an upper and chamber element incorporated therein. As depicted, chamber element  54  includes first barrier layer  58  and second barrier layer  59  that define top subchambers  71 , bottom subchambers  72 , front subchambers  73 , rear subchamber  74 , and internal conduits  88 . 
     In comparison with chamber element  54  of  FIGS. 10-15 , first barrier layer  58  and second barrier layer  59  are depicted in  FIGS. 16-18B  as additionally defining a central subchamber  76 . More specifically, barrier layers  58  and  59  are bonded at bonded areas  75 , portions of which extend around central subchamber  76 . Bonded areas  75  accordingly define a peripheral shape of central subchamber  76 , as well as peripheral shapes of subchambers  71 - 74  and internal conduits  88 . Positioning central subchamber  76  between subchambers  71 - 74  may advantageously allow chamber element  54  to be more resistant to deforming or stressing forces, and to better conform to a wearer&#39;s foot. 
     Fourth Upper and Chamber Element Configuration 
       FIGS. 19-24  depict a fourth configuration of footwear  10  and an upper and chamber element incorporated therein. The chamber element includes a first barrier layer and a second barrier layer that define top subchambers  71 , bottom subchambers  72 , front subchambers  73 , and rear subchamber  74 . In comparison with chamber element  54  of  FIGS. 10-15 , the first barrier layer and second barrier layer of the chamber element of  FIGS. 19-24  additionally define underfoot subchambers  77 , one on lateral side  14 , and one on medial side  15 . 
     Underfoot subchambers  77  extend underneath the interior void defined by the upper, and are positioned to extend through midfoot region  12  and heel region  13  on both lateral side  14  and medial side  15  of footwear  10 . Underfoot subchambers  77  may thus extend underneath an arch area and rear portions of a foot securely received within the interior void. More particularly, underfoot subchambers  77  may extend under tarsus area  120  and calcaneus bone area  122  of the foot of a wearer. Underfoot subchambers  77  may accordingly extend through portions of footwear  10  positioned beneath and associated with tarsus area  120  and calcaneus bone area  122  of the foot of a wearer. 
     In these positions, underfoot subchambers  77  (in combination with subchambers  71 - 74 ) may advantageously increase a stability of footwear  10  in positions corresponding with the bones, joints, and ligaments of the ankle. In addition, subchambers  77  may enhance a fit of an interior surface of footwear  10  against a bottom surface of a wearer&#39;s foot. 
     Subchambers  77  are formed to naturally extend under the interior void when the chamber element is incorporated within footwear  10  to wrap around the ankle area of a wearer&#39;s foot. That is, subchambers  77  are molded or otherwise pre-contoured to extend inward from an exterior of footwear  10  when the chamber element is incorporated within footwear  10 . In alternate configurations, underfoot subchambers  77  may instead be formed to naturally extend toward an exterior of footwear  10 , and may be rotated inward and upward in order to position them under the interior void when the chamber element is incorporated within footwear  10 . 
     Underfoot subchambers  77  are depicted as being exposed to an exterior of footwear  10 , and as forming part of an exterior surface of footwear  10  in midfoot region  12  and heel region  13 . However, other configurations are also possible. For example, subchambers  77  may be partially or entirely surrounded by, encased within, or otherwise embedded within a polymer foam material of the midsole. In some configurations, all of the outward-facing side surfaces of subchambers  77  may form part of an exterior surface of footwear  10 . In other configurations, only part of the outward-facing side surfaces of subchambers  77  may form portions of an exterior surface of footwear  10 . In still further configurations, the outward-facing side surfaces of subchambers  77  may be entirely unexposed to an exterior of footwear  10 , and may thus form no part of the exterior surface of footwear  10 . 
     In addition, underfoot chambers  77  are depicted as not being in fluid communication with subchambers  71 - 74 , and as being separately pressurized or inflated. In various other configurations, however, underfoot subchambers  77  may be in fluid communication with one or more of top subchambers  71 , bottom subchambers  72 , front subchambers  73 , and rear subchamber  74  (through inflation conduits, for example). In other words, in various configurations, underfoot subchambers  77  may or may not be in fluid communication with one or more of the other subchambers of the chamber element. 
     Further Configurations 
     Although depicted in  FIGS. 1-5C  as having apertures  31 - 34  in particular locations along outer layer  27 , and as having subchambers  41 - 44  in particular locations along chamber element  24 , various configurations of footwear  10  may incorporate different numbers of apertures and subchambers, and may incorporate apertures and subchambers in different positions. 
     Some configurations of footwear  10 , for example, may include only rear aperture  34  and rear subchamber  44  extending through it, positioned to extend behind the Achilles tendon of a wearer&#39;s foot. Other configurations may additionally include top apertures  31 , top subchambers  41 , bottom apertures  32 . and bottom subchambers  42 , positioned near lateral and medial sides of the Achilles tendon of a wearer&#39;s foot. In such configurations, subchambers  41 ,  42 , and  44  may make chamber element  24  more resistant to stressing forces around the Achilles tendon, and may in turn improve the stability of footwear  10  and its capacity to that area of the foot. 
     Other configurations of footwear  10  may include only apertures  31 - 33  and corresponding subchambers  41 - 43 , on lateral side  14 , medial side  15 , or both. In such configurations, subchambers  41 - 43  and interior bond  45  between them may make chamber element  24  more resistant to stressing forces around the corresponding side or sides of the foot, and may in turn improve the stability of footwear  10  and its capacity to conform to the foot in that area or those areas. 
     More generally, in various configurations, footwear  10  may include any number of apertures and corresponding subchambers positioned to be near any area or areas of a wearer&#39;s foot, on either lateral side  14 , medial side  15 , or both, and in any of forefoot region  11 , midfoot region  12 , and heel region  13 . For example, footwear  10  may include a rear aperture  34  and a rear subchamber  44 , and may also include one or more additional apertures and corresponding subchambers located in any of a variety of positions along chamber element  24 . 
     Although subchambers  41 - 44  are depicted in  FIGS. 1-7  as having substantially rectangular and triangular configurations, chamber element  24  may be formed to define subchambers having any of a variety of shapes and sizes. For example, as depicted in  FIG. 24 , subchambers  42  and  43  are defined to have substantially oval shapes, while subchambers  41  and  44  are defined to have elongate shapes with rounded ends. Outer layer  27  may also be formed to define apertures having a variety of shapes and sizes, which may correspond with various shapes and sizes of subchambers  41 - 44 . Any shape, size or design for the apertures in outer layer  27  or the subchambers of chamber element  24  is considered to be within the scope of the invention. 
     As depicted in  FIGS. 1-5C , subchambers  41 - 44  protrude through apertures  31 - 34  to form parts of an exterior surface of footwear  10 . Other portions of chamber element  24  may be exposed through apertures in outer layer  27 , however. In some configurations, for example, outer layer  27  may include one or more apertures through which bonded areas of chamber element  24 , such as interior bonds  45 , are exposed. 
     At the same time, portions of chamber element  24  other than subchambers  41 - 44  may protrude through apertures  31 - 34 . For example, interior bonds  45  may be formed to have protrusions that do not contact and lie flush against inner layer  26 , but instead extend through apertures in outer layer  27 . Accordingly, in various configurations, protrusions extending through outer layer  27  may be formed by subchambers  41 - 44  or may be otherwise formed in chamber element  24 . 
       FIGS. 1-8  depict subchambers  41 - 44  as having substantially V-shaped cross-sectional configurations on one side (i.e., as extending outward toward a point or peak), and as bowing slightly outward on an opposite side. Subchambers  41 - 44  may have other cross-sectional configurations, though. As an example,  FIG. 25A  depicts an alternate configuration of chamber element  24  in which subchambers  41  and  42  have substantially rectangular cross-sectional configurations extending outward on both sides. As a further example,  FIG. 25B  depicts another alternate configuration of chamber element  24  in which subchambers  41  and  42  extend toward a point or peak in on both sides. Similarly, in some alternate configurations, subchambers formed in chamber element  24  may bow slightly outward on both sides. Accordingly, in various configurations, subchambers  41 - 44  may have any of a variety of cross-sectional configurations. 
     Furthermore, although  FIGS. 1-8  depict outer layer  27  as having apertures through which subchambers of chamber element  24  extend, and depict inner layer  26  as being in contact with and flush against substantially all of chamber element  24 , footwear  10  may be otherwise configured. For example, as depicted in  FIG. 26A , both inner layer  26  and outer layer  27  may include apertures, and subchambers  41 - 44  may extend through the apertures in inner layer  26  as well as through the apertures in outer layer  27 . Alternatively, inner layer  26  may have a plurality of apertures while outer layer  27  may be substantially continuous and without apertures. In one such configuration, as depicted in  FIG. 26B , subchambers  41 - 44  may extend inward toward a foot of a wearer, while forming slight bulges in an exterior surface of footwear  10  where the subchambers bow slightly outward and are in contact with and flush against outer layer  27 . 
     Chamber element  24  may also be a single fluid-filled chamber, and a portion or portions of chamber element  24  may be exposed through one or more apertures in outer layer  27  to form one or more portions of an exterior surface of footwear  10 . Similarly, one or more portions of chamber element  24  may protrude at least partially through apertures in outer layer  27 . In such configurations, the size and shape of each exposed or protruding portion of chamber element  24  may be defined by the size and shape of the various apertures in outer layer  27 . Various portions of an exterior surface of footwear  10  may accordingly be formed by portions of chamber element  24  exposed through apertures in outer layer  27 , or by portions of chamber element  24  protruding through apertures in outer layer  27 . 
     In some configurations, chamber element  24  may be incorporated into a fluid-filled system for footwear  10  along with one or more fluid-filled chambers in sole structure  50 , such as one or more fluid-filled chambers within a midsole. Furthermore, chamber element  24  may be part of an inflatable system in which pumps, conduits, and valves may pressurize or inflate chamber element  24  with air from the exterior of footwear  10 . In addition, subchambers  41 - 44  may be in fluid communication with each other through internal conduits, and the movement of a wearer&#39;s foot within footwear  10  may decrease a volume of one or more of subchambers  41 - 44  and, in turn, increase a fluid pressure (and potentially a volume) of one or more other subchambers. That is, for configurations in which one or more subchambers  41 - 44  are in fluid communication, movements of a wearer&#39;s foot against some subchambers may adjust the level of inflation in other subchambers, which may in turn allow for the provision of stability and support to various areas of footwear  10  as needed. 
     While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention. For example, aspects of the various configurations of the uppers and chamber elements incorporated therein, as described above and as depicted herein, may be combined. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.