Patent Publication Number: US-2011061269-A1

Title: Water barrier for footwear

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to footwear, and more particularly to footwear for outdoor use. 
     Outdoor footwear products are typically designed to provide, among other things, comfort in a variety of environmental conditions. For example, most outdoor footwear is designed to keep feet dry when exposed to wet or damp conditions, such as that encountered when a wearer traverses water, or engages in activity in rain or snow. If not addressed, such conditions can quickly saturate the footwear with water, possibly causing discomfort, blisters, and bacteria growth if not controlled. 
     Many manufacturers waterproof outdoor footwear to prevent water from entering the footwear and causing the above issues. While this technique works in some cases, it can create additional issues. For example, if the wearer steps in water deeper than the height of the footwear, water will fill the waterproof footwear. Water also may enter waterproof footwear by running down the wearer&#39;s leg into the footwear. After water enters waterproof footwear, the waterproofing features typically prevent water from exiting the footwear and drying out, thereby increasing discomfort for the wearer. Further, the waterproofing features of most waterproof footwear significantly reduce air circulation. In such cases, waterproof footwear can cause excessive perspiration, and can actually contribute to wetness or perspiration build-up within the footwear. 
     While many manufacturers have attempted to provide waterproof footwear with a variety of constructions, there still remains room for improvement. 
     SUMMARY OF THE INVENTION 
     A footwear construction is provided including a system that manages footwear air circulation, as well as moisture and/or water infiltration. 
     In one embodiment, the footwear includes a barrier element that restricts the transfer of water into the footwear. The footwear can include a channel leading from an exterior of the footwear to an interior of the footwear. When contacted with water or other liquid, the barrier element can close at least a portion of the channel to restrict the flow of water or other liquid from the exterior of the footwear to the interior of the footwear, thereby providing a water barrier. 
     In another embodiment, the footwear can include an upper joined with a sole, with at least one of the upper and sole defining the channel. The channel allows air to circulate to the upper. The barrier element can be located in the channel, and can include a phase change material that when wet, swells to close the channel. Optionally, the barrier element can act as a valve to restrict the flow of water into the upper through the channel when subjected to water. 
     In yet another embodiment, the barrier element can include a water absorbing polymer included in a non-woven sheet. When dry, the barrier element can allow air to pass through the channel and circulate to an interior of the upper. When wet, the barrier element can change in dimension, and in so doing, can close at least a portion of the channel to restrict water flow into the footwear. Optionally, the barrier element can be wetted and dried repeatedly, yet still function to restrict water flow into the footwear when wet. 
     In still another embodiment, the sole can include a midsole and an outsole. The channel can be defined in the midsole, and can extend from an exterior of the footwear to an interior of the upper. The barrier element can be at least partially positioned in the channel, and can undergo a phase change to at least partially close the channel when exposed to water, thereby restricting a flow of water from the exterior of the footwear to the interior of the upper. 
     In a further embodiment, the upper of the footwear can include a waterproof membrane. The waterproof membrane can define an opening in fluid communication with the channel that leads to the exterior of the footwear. The opening optionally can be located on the bottom of the upper, adjacent the sole. The barrier element can enable air to circulate through the channel and the opening when dry, yet restrict water from passing through the channel and opening when the barrier element is wet. 
     In yet a further embodiment, a secondary element including a base and a mesh screen can be included in the channel between the barrier element and the exterior of the footwear. The screen can prevent dirt or debris from clogging the exit of the channel to the environment. 
     In still a further embodiment, the barrier element can be located adjacent the secondary element with a gap formed at least partially therebetween. The mesh screen can allow water to pass through the mesh screen to contact the barrier element. The barrier element can swell when contacted with the water that passes through the mesh screen to at least partially close the gap. 
     In another further embodiment, the footwear can include a sealing element joined with a barrier element. The sealing element can be located adjacent a portion of the channel, for example, a hole in the sole, that is in fluid communication with the interior of the footwear. The sealing element can be aligned with the hole so that it closes the hole when the barrier element expands, thereby restricting water from flowing into the hole and further into the footwear interior. 
     The footwear construction herein provides improved ventilation in dry environments, and also provides a substantial barrier to water infiltration in wet environments. The barrier element can be included in channels that provide air flow to the interior of the footwear. The barrier element, when dry, can facilitate the exchange of air between the interior of the upper and the exterior of the footwear via the channels. This provides a somewhat open and breathable structure for the footwear. The barrier element, when wet, can expand in dimension and/or swell to close the channels leading from the footwear exterior to the interior. Optionally, the barrier element can undergo a physical transformation to restrict water from passing through the barrier element. In turn, this can restrict the passage of water into the upper. 
     These and other features and advantages of the present invention will become apparent from the following description of the invention, when viewed in accordance with the accompanying drawings and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is side view of a footwear construction of a current embodiment; 
         FIG. 2  is an exploded perspective view of the footwear; 
         FIG. 3  is a top view of a sole of the footwear; 
         FIG. 4  is a section view of the footwear taken along line  4 - 4  of  FIG. 1  when dry; 
         FIG. 5  is a second section view of the footwear taken along line  4 - 4  of  FIG. 1  when the footwear is subjected to water; 
         FIG. 6  is a section view of the footwear taken along line  6 - 6  of  FIG. 1  when dry; 
         FIG. 7  is a close up view of a barrier element in the footwear shown in  FIG. 6  when dry; 
         FIG. 8  is a second section view of the footwear taken along line  6 - 6  of  FIG. 1  when the footwear is subjected to water; 
         FIG. 9  is a close up view of a barrier element in the footwear shown in  FIG. 4  when the footwear is subjected to water; 
         FIG. 10  is a section view of a first alternative embodiment of the footwear taken along line  6 - 6  of  FIG. 1 ; 
         FIG. 11  is a section view of a second alternative embodiment of the footwear taken along line  6 - 6  of  FIG. 1 ; 
         FIG. 12  is a section view of a third alternative embodiment of the footwear taken along line  6 - 6  of  FIG. 1 ; 
         FIG. 13  is a section view of a fourth alternative embodiment of the footwear taken along line  6 - 6  of  FIG. 1  when dry; and 
         FIG. 14  is a section view of the fourth alternative embodiment of the footwear taken along line  6 - 6  of  FIG. 1  when the footwear is subjected to water. 
     
    
    
     DETAILED DESCRIPTION OF THE CURRENT EMBODIMENTS 
     I. Overview 
     A boot incorporating the construction of a current embodiment is shown in  FIGS. 1-9  and generally designated  10 . For purposes of the disclosure, the embodiment is described in connection with a three-quarter height boot, however, the construction is well suited for use with other types of soled footwear. In general, the boot includes an upper  20  joined with a sole  90 , which can include an outsole  40  and a midsole  30 . The midsole  30  can include a heel wedge  50  located in the heel region  44  of the boot  10 . The midsole  30  also can include channels  60  that extend from an exterior  110  of the footwear to an interior  120  of the upper  20 . These channels  60  can provide fluid communication between the exterior  110  and interior  120 . This fluid communication can provide air flow in to and out from the upper, which in turn can provide improved ventilation to a user&#39;s foot when positioned in the footwear  10 . 
     At least one barrier element  70  is in fluid communication with the channels  60 . The barrier element  70  can be constructed from a variety of materials that undergo a transformation or a phase change that in some manner closes off at least a portion of the one or more channels  60  to restrict water flow from an exterior  110  of the footwear to the interior  120  of the footwear when subjected to water. When dry, the barrier element  70  also allows air to circulate between the interior  120  and the exterior  110 , as described in more detail below. In general, the barrier element  70  provides the relatively open and breathable structure when dry, which allows ample ventilation to the wearer&#39;s foot. The barrier element, however, becomes substantially impassable by water when wet, and generally closes a substantial portion of the channel to prevent water from flowing through it. 
     It is also noted that while the barrier element  70  is primarily illustrated as being utilized in the sole  80  of the footwear, for example, in the midsole  30 , the barrier element  70  can also be utilized in the outsole and/or upper  120  as desired. 
     As used herein, the term “arch region” refers generally to a portion of the shoe corresponding to the arch of the wearer&#39;s foot; the term “forefoot region” refers generally to a portion of the foot forward of the arch region corresponding to the forefoot (for example, the ball and toes) of a wearer&#39;s foot; and the term “heel region” refers generally to that portion of the shoe rearward of the arch region corresponding to the heel of the wearer&#39;s foot. The forefoot region  42 , arch region  43 , and heel region  44  are generally identified in  FIG. 1 ; however, the delineation of these regions may vary depending on the configuration of the footwear. 
     II. Construction 
     Referring to  FIGS. 1-9 , the components of the footwear  10  will now be described in more detail, beginning with the upper  20 . The upper  20  can be generally conventional, and can include a vamp  22 , quarters  24 , and a backstay  26 . Optionally, a removable footbed (not shown) can be positioned inside the upper  20  as desired. With reference to  FIGS. 2 and 4 , the upper  20  includes a lower portion that transitions to an allowance  23 , also referred to as a peripheral allowance, which is folded inward toward the center of the footwear  23 . The footwear  23  can be lasted to a sole board (not shown) or Stroebel stitched to an insole  25  and/or a fabric sock liner. The insole  25  can be generally flexible, and can be cemented, stitched, stapled, or otherwise fastened to the upper, and in particular, the peripheral allowance  23 . The insole  25  can be constructed from a variety of conventional materials. 
     As shown in  FIG. 2 , the insole  25  can define one or more holes or apertures  26 . These apertures  26  can be defined in different portions of the insole  25 , for example, in the forefoot region  42  and in the heel region  44 , or in other combinations of regions as desired. Although shown as being separate, the holes  26  can be a continuous single hole extending from the heel region  44  to the forefoot region  42 . The holes  26  can extend both through the material of the upper  20 , as well as any internal liners (discussed below) used in the upper  20 . 
     The sole  90  can extend upwardly along the sides of the upper a sufficient distance to cover the holes  26  in the bottom of the footwear. Sufficient cement and/or adhesives can also be utilized to act as a water barrier to prevent water from leaking between the upper and the midsole, where they are joined together into the holes  26 , and causing water infiltration at that location. Further optionally, although illustrated as elongate holes, the apertures  26  can be a series of smaller slits or holes. 
     As shown in  FIG. 2 , a mesh  27  can extend across the respective holes  26 . The mesh can be formed from canvas, nylon, metal or polymeric screens, or open pore fabrics or cloth or other synthetic materials. The mesh can be an open, breathable construction that allows moisture and air to freely pass through it with minimal restriction. The mesh can be joined with the adjacent portion of the insole  25  in a variety of manners, for example, by stitching, cementing, or otherwise fastening the mesh to the material surrounding the respective hole  26 . Optionally, in constructions where the insole  25  has sufficient integrity, the mesh can be removed. Further optionally, the insole  25  can be constructed from a breathable, circulation promoting material and the holes  26  and associated mesh  27  can both be absent. 
     In the embodiment shown in  FIG. 2 , the mesh  27  in the openings  26  is generally aligned with respective channel  60  in the heel  44  and forefoot  42  regions of the footwear  10  so that air passing from the exterior  110  of the footwear to the interior of the footwear  120  passes through the channels, as well as the openings  26  and mesh  27 , respectively. 
     As illustrated in  FIG. 4 , the mesh  27  can be aligned with the holes  39  defined in the midsole  30 , which again are further aligned with, and optionally form a part of the channels  60 . In such a configuration, air flow indicated by arrows  113  and  115  can flow into and out from the interior  120  of the footwear in dry conditions. 
     The footwear  10  also can include a liner  28 , also referred to as a waterproof membrane herein. The liner  28  can extend downwardly and terminate adjacent the hole  26  at a periphery  29 . With such a construction, air can circulate from the interior  120  of the upper through the hole  26  and optionally out the channels  60  to the exterior  110  of the footwear. The liner also can extend upwardly to the top of the upper, terminating a second opening that fits around the neck of the ankle of a wearer. 
     In general, the liner or waterproof membrane  29  restricts water from entering the interior of the upper. The waterproof membrane  28  can be constructed from any material, but in the embodiment illustrated, is constructed from a water-impermeable fabric or material. Suitable materials for use to form the waterproof membrane include materials sold under the trademark Gore-Tex, which is commercially available from W.L. Gore &amp; Associates, Inc., of Newark, Del., as well as materials sold under the trademark SYMPATEX, which is commercially available from SympaTex Technologies GmbH of Wuppertal, Germany. Optionally, the waterproof membrane can be constructed from a continuous layer of waterproof thermoplastic or adhesive, which coats the interior of the upper, or further optionally constructed from a polyurethane membrane or latex seam seal construction. Regardless of the materials used, all of the foregoing can be considered to form a waterproof membrane as used herein. Furthermore, although certain materials are not considered to be completely waterproof, that is, they are water resistant or generally form water barriers, they may also be used to construct the waterproof membrane of the footwear  10 . 
     The outsole  40  can be manufactured from a relatively hard rubber or other sufficiently durable or wear-resistant material. The bottom  46  can include an outer surface  48  that forms the wearing surface of the outsole  40 , and can be contoured to the desired heel and trim pattern. The outer surface  48  can be textured to provide traction from the heel to the forefoot if desired. Optionally, the upper surface  47  can be contoured to form portions of the respective channels  60 . 
     As shown in  FIGS. 1-5 , the midsole  30  of the sole  90  can extend from the heel region  44  to the forefoot region  42 , and can be formed as a single, unitary and integral structure. The midsole  30  can include one or more channels  60  extending from the exterior  110  of the footwear inwardly through the midsole  30 . These channels  60  can define openings  61  in the exterior visible surface  31  of the midsole as shown in  FIGS. 1 and 2 . The openings  61  can transition to elongate portions  63  of the channel  60 . 
     The channels can be formed in part by the midsole  30 , as well as the upper surface  47  of the outsole  40 . For example, the channels  60  can be defined partially by the midsole  30 , while a bottom wall of the channel is defined by the upper surface  47  of the outsole. It is noted here that the outsole  40  can be adhered or cemented directly to the midsole  30  in the current embodiment. Of course, the midsole and outsole can be of a integral monolithic structure that is alternatively direct attached to the upper  20  in other applications. The midsole can be constructed from a variety of materials, such as polyurethane, ethyl vinyl acetate, or any other conventional material. 
     Returning to  FIG. 2 , the channels  60  can be defined in both the upper  33  and lower  32  surfaces of the midsole  30 . If desired, the midsole  30  can include multiple lower channels  64  and upper channels  65  that generally intersect one another as described in U.S. Pat. No. 6,701,640 to Nakano, which is hereby incorporated by reference in its entirety. The upper channels and lower channels can intersect at openings  66  to cooperatively provide fluid flow paths vertically through the midsole. A number of the channels  60  in the forefoot are open to the environment via the openings  61 . The channels  68  shown in  FIG. 3  running lengthwise along the midsole  30  can generally connect the channels  60  in the forefoot region and the heel region. Other channel structures can be substituted as desired. For example, the sole  90  can simply include open-ended tube-shaped apertures that open to the exterior  110  through the outsole  40  or through side  31  of the midsole  30 , and extend upwardly to the upper surface  33  of the midsole  30  so that they are in fluid communication with the holes  26  and/or interior  120  of the upper. 
     With reference to  FIG. 3 , a shank  81  can be joined with or molded integrally with the midsole  30  or other component of the footwear as desired. The shank can be positioned at least partially in the arch region  43  and/or the heel region  44  of the footwear, and can be constructed of metal, plastic, or other conventional shank materials. 
     With reference to  FIG. 2 , in the forefoot region  42  of the footwear, the midsole  30  can define grooves  36  which extend generally lengthwise along the sole  90 . These grooves  36  can be generally transverse to and can intersect one or more of the channels  60 . The depth of the grooves  60  can be slightly greater than the vertical depth of the channels. The grooves can be located between the exterior  110  of the footwear and/or the openings  66  that provide fluid communication between the lower channels  64  and the upper channels  65 , which collectively form a part of the channels  60 . Optionally, the grooves  36  can be located between the opening  61  to the holes  26  that lead to the interior  120  of the upper. The grooves  36  can be reproduced on the both the medial and lateral sides of the footwear or wherever the channels  60  open to the exterior of the footwear. 
       FIG. 4  illustrates a cross section of the groove  36  in the forefoot region and its intersection with the channels  60 . In general, the groove  36  is adapted to receive a barrier element  70 . Accordingly, it can be slightly larger than the barrier element  70  so that the barrier element  70  can fit within it. 
     Referring to  FIG. 2 , the sole  90  can include a heel wedge  50 . The heel wedge optionally can be constructed from a different density or durometer material from the midsole. The heel wedge  50  can be fitted into the heel region within a cavity  37  defined by the under surface  32  of the midsole  30 . The heel wedge itself can define multiple subchannels  52  that extend laterally across it. These wedge subchannels  52  are open so that they fluidly communicate with the corresponding channels  60  defined in the heel region of the footwear, which themselves are generally defined in the bottom surface  32  of the midsole. 
     The heel wedge  50  can include multiple additional components and take on a variety of configurations. For example, as illustrated in  FIGS. 2 and 3 , it can include a lateral shoulder  55  extending generally away from the heel wedge lateral sidewall  57 . In general, these two components, the lateral shoulder  55  and the lateral sidewall  57 , can function to form a portion of groove  36  that is transversely oriented relative to one or more channels  60  in the heel region as explained in further detail below. 
     As shown in  FIGS. 2 and 6 , the sole  90  can include barrier elements  70 . These barrier elements  70  can be disposed and the heel and forefoot regions as illustrated, or any combination of the heel, forefoot and arch regions, depending on the particular footwear and activity in which the footwear is to be used. The barrier elements  70  can be constructed of any material or composition which, when dry allows air to pass through and/or around it, but when wet, restricts the flow of water through it and/or around it. Optionally, the barrier element can be constructed from a material or composition which is of a first dimension and generally configured in a reduced mode, when dry. When subjected to water or other liquids, however, the barrier element swells and/or increases in dimension to a swelled mode. When placed in a tight fitting area, the barrier element can swell sufficiently to close gaps or regions between it and immediately adjacent surfaces so that water or liquids are restricted from passing between the barrier element and those surfaces. In the swelled mode, the barrier element also optionally can close off internal passageways to restrict water from flowing through the element. As used herein, restricting a flow of water or liquid generally means that the flow of water can be completely or partially prevented from passing around and/or through a structure or space. 
     Explained in another way, the structure of the barrier element  70  can be such that when it is contacted with water, the water absorbent material (described below) included within it, increases in dimension as it absorbs liquids, and in general, acts as a valve to restrict the flow of water into the upper through the channels when the footwear is subjected to water. For example, the water absorbent material can undergo a volume change and swells or expands. This can cause the overall dimensions of the barrier element to increase. Where the barrier element is placed in close proximity to adjacent components, with relatively small gaps between it and the adjacent components, the swelling causes the barrier element to protrude and project further into those gaps, thereby generally causing them to close. Where the gaps form a portion of channels, the water in the channels can be prevented from moving through the gaps. 
     Further, or alternatively, the barrier element can be constructed so that when dry, air is enabled to circulate directly through the barrier element from a first surface to a second opposing surface on the other side of the barrier element. When subjected to liquid, such as water, the water absorbent polymers, as noted above, swell. This swelling causes the closure of the passage ways between the water absorbent polymers and the fabric or other material within which the water absorbent polymer is embedded. In turn, the closure of the small passageways also further restricts water from passing through the barrier element  70 . 
     The barrier element  70  can include a non-woven material including a water absorbent polymer that expands in size when exposed to water. One such material is referred to as a water expandable non-woven cloth, which is available from Kyowa Rubber Co. Ltd. of Hirakata City, Osaka, Japan. As illustrated in the close up of the non-woven material in  FIG. 7 , the material can generally include multiple, closely packed fibers  71  joined with one another, like a felt, with the water absorbing polymers  72  included within and intermixed among and/or on the fibers. The fibers can be in a fabric form, configured in a web, which can be single or multi-layered, and can include any number of woven or non-woven fibrous webs, including, but not limited to a spun-bound web, an air laid web, and/or a hydro-entangled fibrous web. Further, the fabric can be made up of one or kinds of fibers. The web may contain cotton, reconstituted cellulose fibers, polyester fibers or melt-blown polypropylene fibers in combination with other materials, for example, wood pulp, wood cellulose fibers, and/or lightly bonded melt-blown synthetic fibers. 
     The water absorbent polymers or materials suitable with the footwear  10  include super absorbent polymers that are capable of absorbing several times their own weight of water or aqueous liquids. Some suitable super absorbent polymers can include carboxyl-related polymers that are cross linked by metal ions or organic cross-linking agents when heated and dried on the base web or fabric. The super absorbent polymers can be joined or bonded with the fibers, web or fabric using a suitable manufacturing techniques, for example, those provided in U.S. Pat. No. 5,071,681 to Manning and U.S. Pat. No. 5,451,219 to Suzuki, both of which are incorporated by reference in their entirety. 
     As shown in  FIG. 2 , the barrier element can be provided in sheets or strips to fit within the grooves  36  and optionally traverse multiple channels  60  so that multiple independent barrier elements  70  need not be placed in each individual channel. If desired, however, the barrier elements can be constructed as multiple independent pieces and configured to fit within each individual channel  60 . 
     Although shown as being positioned relatively near the opening  61  of the channels  60 , the barrier element  70  can be positioned further inward within the channels. Further, the channels  60  themselves can include a variety of structures that are interconnected. In general, as used herein, a channel can include any number of connected elements that generally provide collective fluid and/or liquid communication between the exterior  110  of the footwear and the interior  120  of the upper. 
     As shown in  FIGS. 2 ,  3  and  7 , the barrier element  70  in the heel region can be generally positioned in close proximity to the heel wedge  50 . Optionally, the heel wedge  50  can form at least a portion of the grooves  36  of the midsole  30 . For example, the grooves  36  in the heel region adjacent the heel wedge  50  can be bounded by the heel wedge lateral shoulder  55  and a heel wedge sidewall  57 . In addition, the groove  36  can also be bounded by a portion of the midsole cavity  37 , as well as a secondary element  80 . Generally speaking, the groove  36  in the heel can be bounded by multiple components, for example, the bottom-most portion of the midsole cavity  37 , the sidewall  57  of the heel wedge, as well as a lower shoulder  55  of the heel wedge, in addition to the secondary element  80 . Of course, if desired, the groove  36  could be defined by only one, or select ones of these components where included. 
     The footwear can include multiple secondary elements  80  located at least partially in the channels  60 , in the forefoot, arch and/or heel regions of the footwear. The secondary elements  80  can be positioned at least partially within the groove  36  defined by the midsole and transverse at least a portion of one or more channels  60  defined with a midsole. Secondary elements  80 , as shown in  FIGS. 2 ,  6  and  7 , can include a base  82  defining one or more apertures or holes  84 . The apertures  84  generally can be aligned with the channels  60  in the forefoot and heel regions of the footwear. The secondary elements  80  can also include a mesh  86  positioned within the holes  24 . The mesh  60  can generally extend across the entire openings or at least a portion of the openings. This mesh can be any of the types of mesh explained above. 
     In general, the mesh  86  is aligned with the barrier element  80  within the channel  60 . When the footwear is subjected to water, the mesh is of a sufficient size to allow water to pass through it to contact the barrier element and initiate a physical transformation of the barrier element in which it swells to restrict water from flowing through and/or around it. 
     The mesh  86  can be in the form of a screen that restricts mud and other solids or debris from passing into the sole  90  through openings  61 , farther into the channels  60  toward the interior  120  of the footwear  10 . The mesh optionally can be molded over by the material from which the base  82  is constructed. The base  82  can generally be a molded plastic or composite or other substrate that is molded directly over the mesh  86  to join the mesh and the base. Alternatively, the mesh can be glued, cemented or otherwise fastened to the base. Of course, if desired, the base  82  and mesh  86  can be completely separate elements simply placed adjacent one another. 
     As shown in  FIGS. 2 and 4 , the barrier element  70  can be placed adjacent the base  82 , and in general, the secondary element  80 . Both of these components can be configured so that they fit side-by-side one another in the groove  36 . The components also can be joined with one another via spot gluing or other joining techniques. Where spot glued, the components can still enable air to flow between them relatively freely. Thus, spot gluing does not form an air-impervious glue barrier around the respective channels. Of course, where water or air permeable glue is used, or in circumstances where the barrier element is very porous, allowing sufficient air flow through it, a continuous bead of glue can be utilized. If the construction does not utilize the secondary element  80 , the barrier element  70  can be spot glued directly to the midsole or attached via other fasteners or cement or bonding devices to the midsole  30 . Alternatively, the barrier element  70  and/or the secondary element  80  can be loosely positioned within the groove  36  defined by the midsole, and held there simply by virtue of it being entrapped within the groove when the outsole  40  is joined with the midsole  30 . 
     As shown in  FIGS. 4 and 7 , the barrier element  70  can be positioned within the groove so that gaps  77  and  78  are established between the barrier element  80  and the remainder of the midsole  30  and/or secondary element  80  and/or heel wedge  50 . In general, the gaps between the barrier element  80  and other components of the footwear  10  can be variable in dimension. For example, when the barrier element  70  is relatively dry, that is, it has not been recently subjected to water or moisture, the gaps  77  and  78  achieve their greatest dimensions. When the barrier element  70  is subjected to water, it swells and optionally changes dimensions so that the gaps  77  and  78  achieve their smallest dimensions. In many cases, the smallest dimensions of the gaps are small enough that water cannot easily pass or flow through them. 
     The gaps  77  and  78  generally can form a part of the channel  60 . In cooperation with the other portions of the channels  60 , when dry, the gaps enable air to circulate to the interior  120  of the upper from the exterior or environment  110  of the footwear. Although the various gaps  77  and  78  are illustrated as being relatively open, given the structure of some embodiments of the barrier element, the fibers  71  (where included) of the barrier element  70  can project into the gaps, and in some cases touch adjacent components, such as, the secondary element, the heel wedge, or other midsole components. Despite having the fibers  71  or other structures projecting into them, these spaces  77  and  78  are still considered gaps for purposes of this disclosure. 
     III. Operation and Manufacture 
     The operation of a current embodiment of the footwear  10  will now be described. In general, the footwear  10  is adapted to provide a system that manages air circulation as well as moisture and/or water infiltration into the footwear. As shown in  FIGS. 1-3 , the channels  60  open to the exterior  110 . The channels, although formed from a variety of different components and compartments, are in fluid communication with the interior of the upper  120 . The channels, however, are also in fluid communication with one or more barrier elements  70 . The barrier elements  70  can be at least partially positioned within the channels  60 . In a normal dry environment, where the exterior of the footwear is generally dry as shown in  FIGS. 4 and 7 , the barrier elements  70  can be configured so that air can travel freely through the barrier  70  as well as around the barrier, through the gaps  77  and  78  located between the barrier and other components of the footwear. The air can travel in and out of the footwear to provide improved circulation to the wearer&#39;s foot within the interior  120  of the footwear. 
     For example, as shown in  FIGS. 6 and 7 , air flows through the channels  60  as illustrated by the various arrows. The barrier element  70  allows the air to flow in to and out from the interior  120  directly through the barrier element and/or around the barrier element, through the gaps  77  and  78  adjacent the barrier element. 
     The construction of the footwear in the heel region  44  can also be configured so that it enhances air circulation. As shown in  FIG. 6 , when a user exerts force on the top plate  34  of the midsole  30 , for example, when the wearer&#39;s heel strikes the heel plate  34  in the direction of arrow  158 , the heel plate  34  can deflect slightly, as shown in phantom lines. In turn, this causes air to exhaust from the interior  120  of the footwear as well as the chambers  35  of the midsole and/or heel wedge  50 . When the wearer continues their stride, and the heel is drawn off the heel plate  34  in the direction of the arrow  156 , air is rapidly drawn into the interior  120  of the footwear, around and/or through the barrier element  70 . This can provide increased air circulation. In general, when the barrier element is dry, it is relatively “open.” Accordingly, air can pass relatively easily through and/or around it, within the channels, providing a high degree of ventilation. When in this relatively dry form, the barrier element is generally referred to as being configured in its reduced mode. 
     The barrier element  70  undergoes a phase change or transformation when it becomes wetted with liquid, such as water. As a result, the barrier element  70  functions to restrict water flow into the interior  120  of the upper. In turn, this can provide a highly efficient water barrier. In general, when the barrier element becomes wet, the water absorbent polymers or other material within it absorb water and begin to physically swell. As the swelling continues, the internal passageways of the barrier element become substantially closed and/or constructed. The barrier element  70  also swells against other components of the footwear to effectively close off gaps  77 ,  78 , or other gaps, that were previously adjacent the barrier element that allowed air to circulate by or around the barrier element. With the constriction or closure of the internal passageways and gaps adjacent the barrier element, the barrier element provides a barrier to the flow of water through the channel  60  and into the interior  120  of the footwear. Where the waterproof membrane  28  is included, that membrane provides waterproofing to the upper  20  above the sole  90 . 
     Depending on the particular material used to construct the barrier element  70 , the barrier element may or may not prevent all liquids and/or water from passing through it or around it and into the interior of the footwear. Optionally, it at least restricts water flow so that the interior of the footwear  120  is not substantially wetted from water passing completely through the channel  60  into the interior  120 . 
     More specific examples of the operation of the footwear are shown in  FIGS. 4 and 5 . In  FIG. 4 , the footwear is in a dry environment were water has not contacted the barrier element  70 . Accordingly, air continues to circulate around the barrier element  70 . However, as shown in  FIG. 5 , when water or liquid from the footwear  10  is subjected to water or liquid on its exterior  110 , the water travels into the channels  60  and engages and contacts the barrier element  70 . The barrier element  70  swells and expands to at least partially close the former gaps  77 ,  78  around the barrier element  70 . The internal passageways of the barrier element  70  are also at least partially closed. In turn, the barrier element acts as a water barrier to restrict the flow of water through the channels  60  into the interior  120  of the footwear. 
     Referring to  FIGS. 6 and 8 , the operation of the water barrier in the heel is generally illustrated. Again,  FIG. 6  illustrates free movement and flow of air to and from the interior and exterior  110  and  120  in a dry environment. When the footwear  10  is subjected to water as shown in  FIG. 8 , the barrier element  70  swells or expands in dimension from its reduced mode to its expanded mode. In so doing, it closes off the channel  60  so that the water is restricted from passing through the channel  60  from the exterior  110  to the interior  120 . While the barrier element is subjected to water, it maintains its transformed state so that it continues to restrict water from entering the interior  120  of the footwear through the channel  60 . 
     After the footwear  10  is removed from the wet environment, that is, it is no longer subjected to water, the barrier element  70  can begin drying out. As it does, it transforms from its swelled mode back to its reduced mode and in so doing, reduces in dimension. This in turn causes the various gaps  77 ,  78  around the barrier elements to reopen to an air circulating configuration. Additionally, where included, the internal passageways that extend generally through the barrier element  70  reopen so that air can begin to circulate through the barrier element as well. In this manner, the barrier element is able to regenerate itself to provide air circulation again after it dries out. However, when it becomes wet again or subject to water, it will again restrict the flow of water from the environment  110  into the interior  120  of the footwear  10 . 
     The manufacture of the footwear will now be described with reference to  FIGS. 1-4 . In general, the upper  20  is manufactured using conventional techniques and apparatus. For example, the desired upper material (not shown) can be cut to form the upper  20 . The multiple elements of the upper  20  such as the vamp  22 , quarters  24  and back stay  26  are fitted and sewn together. The optional waterproof membrane or liner  28  can be secured within the upper via adhesives or stitching that does not deteriorate the water impermeability of the membrane or liner in the desired areas. The liner  28  can also be fitted to the upper so that in the finished footwear  10  it extends downward a sufficient distance so that the later-added midsole  30  terminates above the lowermost portion of the liner. 
     The peripheral allowance  23  can be Stroebel stitched or otherwise attached to the insole  28 . The insole  28  can be prefinished to include holes  26  and the respective mesh  27  within the holes. The outsole  40 , midsole  30  and heel wedge  50  can be manufactured including the features described above. These components can be injection molded or porer molded from the respective materials as discussed above. 
     With the midsole manufactured, it can be outfitted with strips of the barrier elements  70  disposed within the respective grooves  36 . If utilized, the secondary element  80  including the base  84  and mesh  86  can be included in the grooves  36 , generally between the barrier element and the opening  61  of the channel  60 . If desired, the secondary element  80  can be glued within the groove. The barrier element  70  also can be spot glued within the groove  36  to the midsole and/or the secondary element  80 , generally positioned transverse to one or more channels  60  in the sole  80 . 
     With the barrier element  70 , and where included, the secondary elements  80  in place in the groove, the outsole  40  can be adhered to the midsole  30 . In so doing, the outsole  40  as illustrated can complete the channels  60  on the underside of the midsole  30 . With the midsole and outsole joined with one another, the sole  80  is adhered or cemented to the upper  20 . 
     With the sole  80  joined with the upper, the finished footwear  10  can undergo a number of conventional finishing operations. For example, the midsole  30  and outsole  40  and other parts thereof can be trimmed and shaped. The upper  20  can be clean, polished and treated as desired. 
     IV. First Alternative Embodiment 
     A first alternative embodiment of the footwear is illustrated in  FIG. 10 . This footwear is similar to the embodiment described above with several exceptions. For example, the sole  280  generally does not include a heel wedge. Instead, it includes a structure having a tray-like or u-shaped barrier element  270  positioned adjacent a secondary element  280 . The secondary element  280  can include the mesh screen as described above to prevent debris from entering the footwear. The sole  280  can also define multiple sets of channels  260  and  266 . The channel  260  includes an opening  261  defined in a sidewall  231  of the midsole  230 . The sole  280  also can include a second larger channel  266  that extends through the outsole  240  as well as a portion of the midsole  230 . The lower portion of the barrier element  270  facing the channel  266  can be adjacent a mesh  286  included in the secondary element  280 . Optionally, the mesh  286  can be a completely separate element. Indeed, the mesh  286  can be joined with a portion of the barrier element  270  as desired. 
     This construction operates in a similar manner to that of the embodiment described above, with air flowing from the exterior  110  into and out from the interior  120  through the channels  260  and  266  as shown with the arrows. Again, as explained above, the barrier element can enable the air flow to pass directly through the element and/or around gaps between the element and another component of the footwear. When wetted, the barrier element operates to restrict flow through the channels  266  and  260 , and generally to prevent the flow of water into the interior  120  of the footwear. 
     V. Second Alternative Embodiment 
     A second alternative embodiment of the footwear  310  is generally illustrated in  FIG. 11 . This embodiment is similar to the embodiments described above with several exceptions. For example, instead of having channels that open through the exterior sidewalls  331  of the midsole  330 , this construction can include a large channel  366  opening through the outsole  340  and the lower portion of the midsole  330  to the environment. Like the first alternative embodiment described above, a barrier element  370  can be positioned adjacent a secondary element  380 . A mesh screen  386  can be positioned immediately adjacent the barrier element to prevent dirt and debris from entering the barrier element and/or the interior  120  of the footwear. The barrier element  370  can be of a generally planar configuration, in the form of a widened strip or sheet, extending across the channel  366 . When dry, the barrier element allows air to travel through the channel  366  from the exterior  110  into and out from the interior  120  of the footwear. When wet, the barrier element  370  operates in the same manner as described in the embodiments above, generally restricting liquid, such as water, from passing around and/or through the barrier element. In turn, this provides a water barrier to keep the interior  120  of the footwear relatively dry. 
     VI. Third Alternative Embodiment 
       FIG. 12  generally illustrates a third alternative embodiment of the footwear  410 , which is similar to the above embodiments with several exceptions. For example, the midsole  430  and the sole  480  in general can define channels  460  extending inwardly from the sidewalls  431 . These channels  431  can be in fluid communication with the interior  120  of the footwear  410 . A chamber  435  can form a portion of the channels  460  as desired. The barrier element  470  can be positioned within the sidewalls  431 . These barrier elements can be of a special configuration and can have a desired geometric cross section, for example, a circular, square, elliptical or other polygonal cross section, that generally matches the geometric cross section of the portion of the channels  460  within which they are positioned. A mesh screen  486  can be embedded in the material of the midsole generally between the opening  461  of the channels and the barrier element  470 . The barrier element also can include an enlarged internal passageway  471 . The added passageway  471  can increase air flow into and out from the footwear and air circulation in general. A gap  477  can be formed around the perimeter of the barrier element  470 . The barrier element  470  can be spot glued with adhesive  479  within the channel  460 . 
     Air can flow directly through the barrier element  470  through its internal passage  471  and/or around the barrier element through the gap  477  into and out from the interior  120  of the footwear. When subjected to water, however, the barrier element  470  can act as a valve and swell from a reduced mode to a swelled mode, in which it closes the gap  477  adjacent the element  470 , as well as the internal passageway  471  extending through the element  470 . In turn, water is restricted from flowing through or around the gap. In effect, the barrier element at least partially closes off the channel to prevent water from passing from the exterior  110  into the interior  120  of the footwear. If desired, a heel button or other cushion (not shown) can be positioned within the compartment  435 . Optionally, however, the cushion can be dimensioned so that it does not completely close off the fluid communication between the openings  439  in the upper plate  434  of the midsole and the channels  460 . 
     VII. Fourth Alternative Embodiment 
     A fourth alternative embodiment of the footwear  510  is generally illustrated in  FIGS. 13 and 14 . This embodiment is similar to the embodiments described above with several exceptions. For example, the operation and construction of the barrier elements  570  differs from that of the above embodiments. This embodiment includes channels  560  that are in fluid communication with a chamber  535  which is further in communication with openings  539  in the sole  590  that open to the interior  120  of the footwear  510 . As shown, the sole  590  includes a chamber  535  defined in the midsole  530 . This chamber  535  is in fluid communication with the channels  560 . One or more screens  586  are disposed in the channel and/or chamber  535 . The barrier elements  570  can be constructed of the same materials described in the embodiments above. Joined with these barrier elements  570  are sealing elements  505 . The sealing elements  505  can be constructed from rubber, polymers, nylon, EVA, PVC, or a variety of other materials. 
     The sealing elements  505  are generally aligned with the holes  539  that lead to the interior  120  of the footwear. The sealing elements  505  generally include a base  506  that extends across a portion of the individual barrier elements  570 . The base  505  can be joined with the respective barrier element  570  in a variety of manners, for example, by cement, adhesives, stitching or other fastening mechanisms. The base can further optionally include a guide element  507 , which extends upwardly toward the opening  539  with which the respective sealing element  505  is aligned. In general, the guiding element  507  can operate to generally center the base  506  relative to the opening  509 . Of course, the guiding element  507  can be absent from the construction if desired. 
     Although shown as multiple separate sealing elements  505  (as illustrated there are three sealing elements), multiple sealing elements can be combined together as one sealing element, and can extend across multiple openings  539  heading to the interior  120  of the footwear  510 . Further, although shown as three separate barrier elements  570 , the barrier elements  570  can be combined into a single barrier element  571  (shown in phantom lines) with the respective sealing elements  505  joined with that single barrier element  571 . 
     The sole  590  can include a secondary openings  583  defined in a secondary element  580 . These secondary openings  583  generally open to a large channel  566  defined through the lower portion of the sole  590 , and in particular the lower portion of the midsole  530  and outsole  540 . 
     Referring to  FIG. 13 , each of the individual barrier elements  570  can be joined with the secondary element  580  and held in place and/or trapped by a seat  589 . Of course, the barrier element can be glued, adhered or otherwise fastened at its lower portion to the seat  589 , or generally to the surface of the secondary element  580  facing the chamber  535 . 
     In operation, like the above embodiments, the barrier element  570  generally enables air to travel through the channels  560  through the openings  539  in the sole  590  into and out from the interior  120  of the footwear  110 . For example, air can flow from the exterior  110  through the channels  560  into the compartment  535  through the opening  539  as well as through the mesh  527  into the interior  120  of the upper. Air may flow in the opposite direction as well. In general, the openings  539 , as well as the chamber  535  can be considered part of the channel  560 , as these elements are all in fluid communication with one another. Optionally, air also can flow through the lower channel  566 , through the openings  583 , the chamber  535 , the openings  539 , through the mesh  527 , and into or out from the interior  120 . 
     As illustrated in  FIG. 13 , when dry, the barrier elements  370  are in a reduced mode. Accordingly, air can flow past the sealing elements  505  into or out from the interior  120  of the footwear and through the respective channels  560  and  566 . When, however, the barrier elements are subjected to liquids or water, they expand. Accordingly, each individual barrier element  570  increases in dimension, which causes the barrier element to urge the sealing element  505  toward the area surrounding the respective holes  539  that lead to the interior  120  of the upper  520 . Expansion continues until the barrier elements  570  press the sealing elements  505  into sealing engagement with the surface  538  adjacent the holes  539 . The guiding elements  505 , where included, generally guide the sealing element, aligning the base with the holes  539  so that the base engages the surface  538  to seal the holes. Accordingly, with the holes  539  sealed by the respective sealing elements  505 , water is restricted, and in some cases completely prevented, from entering the interior  120  through the holes  539 . Of course, other combinations and variations of the constructions for the barrier elements and sealing elements can be substituted for that shown in  FIGS. 13 and 14 . 
     Generally speaking, the barrier element undergoes a phase change, which in turn causes the barrier element to expand, pushing the sealing element  505  into sealing engagement with the surface  538 , thereby effectively closing off the channel  560  which leads to the interior  120 . This restricts the flow of water from the exterior  110  to the interior  120  of the upper  520  when the footwear is subject to water as shown, for example, in  FIG. 14 . 
     The above description is that of the current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.