Patent Publication Number: US-8109012-B2

Title: Article of footwear with drainage features

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an article of footwear having drainage capabilities, and more particularly to an article of footwear configured with drainage holes so that water cannot accumulate in the article of footwear, such as when showering. 
     2. Description of Related Art 
     Increasingly, people wear articles of footwear in or near water to protect their feet. For example, some people wear articles of footwear at the beach or in rivers and streams so that their feet are protected from cuts and abrasions from rocks or other environmental hazards. Similarly, some people wear articles of footwear in public showers so that their feet are protected from biological hazards, such as fungus. 
     While articles of footwear may protect the foot from contact with undesirable surfaces, these articles of footwear may accumulate water inside the article of footwear, which can be uncomfortable. Additionally, prolonged exposure to standing water may weaken the skin of the foot, allowing bacteria, fungus, or molds to attach to the skin or even break through the skin and cause an infection or other growth on the foot. 
     Articles of footwear for use in or around water have, therefore, been provided with drainage capabilities. For example U.S. patent application publication number 2002/0088140 to Wang et al. discloses a sole for footwear that is configured to drain water away from the wearer&#39;s foot. The sole includes a plurality of protrusions extending from a top surface of the sole and a plurality of apertures defined through the sole body between the protrusions. The protrusions support the foot. The protrusions may be conical, ribs, or rods. The apertures allow water to drain away from the foot. The apertures extend over the entire length and width of the sole so that water may drain through the sole at any location on the sole. 
     Another article of footwear incorporating drainage features is disclosed in U.S. patent publication number 2005/0262726 to Ferniani et al. The &#39;726 publication discloses a sandal having an upper, an insole, and a sole. The sole includes a recess with which the insole may be engaged. The sole includes a series of channels for collecting and guiding water to drainage holes formed through the sole. The insole is porous and covers the drainage holes. Water entering the shoe may flow through the insole and into the channels, where the water is directed to the drainage holes. 
     While there are articles of footwear having water drainage capabilities, there exists a need in the art for features that may improve the drainage of water from the sole. 
     SUMMARY OF THE INVENTION 
     An article of footwear includes drainage features to direct water away from the foot of a wearer. The drainage features include drainage holes, which may be substantially vertical channels formed through the sole of the article of footwear. A series of ribs support the foot away from the drainage features, which may be disposed between the ribs. 
     In one aspect, the invention provides an article of footwear comprising a sole comprising an outsole and an element configured to support a foot away from the outsole; a plurality of ribs formed on the element so that a groove is disposed between at least one set of adjacent ribs; a drainage hole disposed in the groove, wherein the drainage hole is formed at or near a transverse centerpoint of the groove; and wherein each rib includes a raised center portion. 
     In another aspect, the element has a contoured lower surface configured to direct water to the drainage hole. 
     In another aspect, the contoured lower surface has a cusp region, wherein the drainage hole is positioned at or near the cusp region. 
     In another aspect, the contoured lower surface is substantially concave. 
     In another aspect, an upper is associated with the sole. 
     In another aspect, the drainage hole is a substantially vertical channel formed through the sole. 
     In another aspect, the invention provides an article of footwear comprising a sole comprising an outsole and an element configured to support a foot away from the outsole; a plurality of ribs formed on the element so that a groove is disposed between at least one set of adjacent ribs, wherein each rib includes a raised center portion; the element having a contoured lower surface, the contoured lower surface having a cusp region; and a drainage hole disposed in the groove and positioned near the cusp region. 
     In another aspect, the cusp region is positioned near a transverse centerpoint of the groove. 
     In another aspect, the cusp region is positioned at a transverse centerpoint of the groove. 
     In another aspect, the drainage hole is aligned with the raised center portions of the ribs. 
     In another aspect, an upper is associated with the sole. 
     In another aspect, the contoured surface is concave. 
     In another aspect, the drainage hole is a substantially vertical channel formed through the sole. 
     In another aspect, the invention provides an article of footwear comprising an upper; a sole attached to the upper; an element associated with the sole, the element configured to support a foot away from the sole; a plurality of spaced apart ribs disposed on the element, wherein each rib has a raised center portion; a drainage feature formed through the sole; an inlet to the drainage feature disposed between adjacent ribs. 
     In another aspect, the drainage feature is a drainage hole. 
     In another aspect, the drainage hole comprises a vertical channel through the sole. 
     In another aspect, the ribbed element includes a contoured lower surface configured to direct water to the drainage feature. 
     In another aspect, the contoured lower surface is concave. 
     In another aspect, the upper includes a first section and a second section, wherein the first section is removably attachable to the second section. 
     In another aspect, the upper includes a first layer associated with a second layer. 
     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 rear perspective view of an embodiment of an article of footwear having drainage features; 
         FIG. 2  is a top plan view of an embodiment of an article of footwear having drainage features; 
         FIG. 3  is a bottom plan view of an embodiment of an article of footwear having drainage features; 
         FIG. 4  is a front view of an embodiment of an article of footwear having drainage features; 
         FIG. 5  is a cross-sectional view of the article of footwear shown in  FIG. 2 ; 
         FIG. 6  is a perspective view of an embodiment of an article of footwear having drainage capabilities as worn by a user in water; 
         FIG. 7  is a perspective view of the article of footwear shown in  FIG. 6  with the user&#39;s foot shown in phantom; 
         FIG. 8  is a cross-sectional view of the article of footwear shown in  FIG. 6  showing the flow of water through the article of footwear; 
         FIG. 9  is an exploded view of an embodiment of an article of footwear having drainage features; 
         FIG. 10  a perspective view of an embodiment of an article of footwear having drainage features and a one-piece sole; 
         FIG. 11  is a top plan view of an embodiment of an article of footwear having drainage features and a one-piece sole; 
         FIG. 12  is a perspective view of an embodiment of an article of footwear having drainage features and an alternate upper configuration; 
         FIG. 13  is a top plan view of the article of footwear shown in  FIG. 12  with the upper in a closed configuration; 
         FIG. 14  is a top plan view of the article of footwear shown in  FIG. 12  with the upper in an open configuration. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An article of footwear is provided with features for draining water to prevent water from accumulating underneath and around the foot of a wearer of the article of footwear. The following discussion and accompanying figures disclose an article of footwear, particularly a sole structure of the footwear. Concepts related to the sole structure are disclosed with reference to footwear having a configuration that is suitable for use in or around water. The sole structure is not limited solely to such footwear, however, and may be utilized with a wide range of footwear styles. An individual skilled in the relevant art will appreciate, therefore, that the concepts disclosed herein apply to a wide variety of footwear styles, in addition to the specific style discussed in the following material and depicted in the accompanying figures. 
     The figures show an embodiment of an article of footwear  100  provided with drainage features. Only one article of footwear  100  is shown and discussed herein, although a mirror image article of footwear  100  may be provided to form a pair for use by a wearer. Article of footwear  100  generally includes an upper  102  associated with a sole  104 . 
     Upper  102  may be any type of upper known in the art. Upper  102  is depicted as having a substantially conventional configuration incorporating a plurality of material elements (e.g., textiles, foam, leather, and synthetic leather) that are stitched or adhesively bonded together to form an interior void for securely and comfortably receiving a foot. Given that various aspects of the present application primarily relate to sole  104 , upper  102  may exhibit the general configuration discussed above or the general configuration of practically any other conventional or non-conventional upper. Accordingly, the structure of upper  102  utilized with sole  104  or variants thereof may vary significantly. 
     In the embodiment shown in  FIGS. 1-4 , upper  102  is configured so that a user may slide a foot into upper  102 . Upper  102  may extend entirely across sole  104  in a transverse direction and only partially along sole  104  in a longitudinal direction. In other embodiments, upper  102  may have other configurations, such as providing a partition or partitions between the toes, providing straps, or by having upper  102  cover a greater portion of the wearer&#39;s foot. 
     Upper  102  may be made of any material known in the art, but is preferably made of a water-resistant material such as vinyl, plastic, or the like. In some embodiments, upper  102  may be made from a porous material coated or sealed with a water-resistant material. 
     Upper  102  is preferably associated with sole  104 . In some embodiments, upper  102  may be fixedly or removably attached to sole  104 . Upper  102  may be associated with sole  104  using any method known in the art, such as by welding, stitching, co-molding, over-molding, joined with an adhesive, or joined with a mechanical fastener. Mechanical fasteners may include a hook-and-loop fastener, snaps, buckles, zippers, or the like. In the embodiment shown in the figures, upper  102  is attached to sole  104  on the periphery of sole  104 . In other embodiments, upper  102  may be attached to sole  104  in other locations. 
     Sole  104  generally includes an outsole  106  that forms the main body of sole  104  and a ribbed element  108  for supporting the wearer&#39;s foot. Outsole  106  may be made of any material typically used for ground-engaging surfaces for articles of footwear, such as rubber, silicone, or the like. Outsole  106  may include surface texture or treads  109  for traction between outsole  106  and the ground. Outsole  106  may be made as a single layer or may be made of multiple layers. In one embodiment, outsole  106  may be molded from a single material as a unitary element. In other embodiments, outsole  106  may include multiple layers associated with each other using any method known in the art, such as with an adhesive, by welding, or the like. 
     To enhance drainage, article of footwear  100  may include provisions that lift a wearer&#39;s foot away from outsole  106 . In some embodiments, these provisions may include ribs or protrusions that extend away from outsole  106 . As shown in  FIGS. 1-4 , article of footwear  100  is provided with a plurality of ribs  110 . Ribs  110  extend away from outsole  106  so that the wearer&#39;s foot rests on ribs  110  and is supported away from outsole  106 . In some embodiments, ribs  110  may be spaced apart elongated elements. In some embodiments, ribs  110  may be parallel to each other and spaced apart to form grooves  117  between adjacent ribs  110 . Grooves  117  may be uniform in size along the length and width of sole  104 , or grooves  117  may have different sizes, such as if ribs  110  are not evenly spaced apart or if a single groove  117  may have wider and narrower portions. 
     In other embodiments, other provisions may be used to support a wearer&#39;s foot away from outsole  106 , such as other types of protrusions, a net or net-like structure stretched across article of footwear  100  so that the wearer&#39;s foot is suspended over outsole  106 , or any other type of element that may be used to support the wearer&#39;s foot away from outsole  106 . 
     In some embodiments, ribs  110  may be formed as part of a ribbed element  108 . Ribbed element  108  may be a unitary element that extends at least partially along the length of outsole  106 . In some embodiments, ribbed element  108  may be substantially co-extensive with outsole  106 , as shown in  FIGS. 1-4  and  7 . In other embodiments, ribbed element  108  may extend only along a portion of outsole  106 . Ribbed element  108  may be formed separately from outsole  106  and associated with outsole  106  using any method known in the art, such as by over-molding or with an adhesive. Examples of various types of adhesives that could be used include, but are not limited to natural adhesives, synthetic adhesives, drying adhesives, contact adhesives, hot melt adhesives (such as thermoplastic adhesives) and pressure sensitive adhesives. 
     In some embodiments, ribbed element  108  may be made from the same material as outsole  106 . In such embodiments, ribbed element  108  may be co-formed with outsole  106 . In other embodiments, ribbed element  108  may be formed from a different material than outsole  106 . In some embodiments, ribbed element  108  may be made from a stiffer material than outsole  106  so that ribs  110  resist bending when a wearer&#39;s foot applied pressure to ribs  110 . In some embodiments, ribbed element  108  may be made from a plurality of materials, such as a relatively stiff material coated or covered with a softer material. In these embodiments, ribs  110  resist bending due to the stiff inner material while the foot of the wearer is cushioned against the softer outer material. 
     In some embodiments, sole  104  may include provisions that may move fluid away from a wearer&#39;s foot. In some embodiments, sole  104  may be provided with drainage features and other features that enhance the drainage capabilities of sole  104 . In one embodiment, the drainage features include drainage holes  112 . Drainage holes  112  may be openings formed entirely through sole  104 , through both outsole  106  and ribbed element  108 . In some embodiments, drainage holes  112  form a relatively straight flow path through sole  104 . In some embodiments, as shown in  FIG. 5 , drainage holes  112  may be substantially straight vertical channels formed through sole  104 . 
     Drainage holes  112  may have any cross-sectional shape known in the art, such as circular, elliptical, polygonal, or the like. In some embodiments, the cross-sectional shape of drainage holes  112  does not include corners or other sharp angles in order to resist the accumulation of water or debris. Drainage holes  112  may have any desired size. In the embodiment shown in the figures, for example, drainage holes  112  may have different sizes. In other embodiments, all drainage holes  112  may be the same size or similarly sized. 
     In some embodiments, drainage holes  112  may be used to evacuate fluid from article of footwear  100 . In some embodiments, drainage holes  112  may be used to evacuate fluid that may accumulate near a wearer&#39;s foot toward outsole  106 , through outsole  106 , or away from outsole  106 . Drainage holes  112  may be positioned along sole  104  anywhere that fluid may accumulate. Any number of drainage holes  112  may be provided, such as a single hole or multiple holes. 
     In one embodiment, such as the embodiment shown in the figures, drainage holes  112  may be positioned in a groove  117  between at least one set of adjacent ribs  110 . In some embodiments, each groove  117  may include at least one drainage hole  112 . In other embodiments, only select grooves  117  may include at least one drainage hole  112 . In the embodiment shown in the figures, only a single drainage hole  112  is placed in any groove  117  and only select grooves  117  contain drainage holes  112 . In other embodiments, multiple drainage holes  112  may be placed in a single groove  117 . As best shown in  FIGS. 2 and 3 , in some embodiments, drainage holes  112  may be positioned generally along a centerline  114  of article of footwear  100 . 
     As shown in  FIG. 8 , a lower surface  122  of ribbed element  108  and an upper surface  123  of outsole  106  may be contoured to control the flow of fluid. This contouring may be generally concave, with the lowest point or cusp or region containing the lowest point or cusp region of the contouring being established at or near the transverse centerpoint  115  of sole  104 . In other embodiments, the contouring may have its lowest point or cusp region containing the lowest point or cusp region at other positions on sole  104 , such as on a lateral and/or medial side of sole  104 , in a toe region of sole  104 , in a heel region of sole  104 . In other embodiments, the contouring may have multiple low points, so that fluid may be directed towards a number of different spots on sole  104 . The contouring may be smooth, as shown in the figures, to form a bowl or cup-like cross-sectional shape. In other embodiments, however, the contouring may have other cross-sectional shapes, such as stepped, parabolic, frustoconical, wavy, or combinations of these shapes. 
     By positioning drainage holes  112  generally along centerline  114 , water may flow along the contour of lower surface  122  of ribbed element  108  so that the water is directed to drainage holes  112 . This enhances the ability of water to drain from sole  104  and away from the foot of the wearer. 
     Additionally, ribs  110  may include provisions that further enhance drainage capabilities of article of footwear  100 . In some embodiments, ribs  110  may include provisions that lift portions of the wearer&#39;s foot further away from outsole  106  than other portions of the wearer&#39;s foot. In some embodiments, ribs  110  may be contoured. In some embodiments, ribs  110  may be contoured to include raised portions. The raised portion may be positioned at any point along rib  110 . In some embodiments, the raised portion may be positioned to correspond to the location of a drainage hole  112 . 
     In the embodiment shown in the figures, as best seen in  FIGS. 4 ,  5 , and  8 , ribs  110  are contoured so that each rib  110  includes a raised center portion  116 . The raised center portions  116  of ribs  110  are generally positioned to follow centerline  114 . Therefore, as best shown in  FIGS. 5 and 8 , each drainage hole  112  is positioned substantially beneath the raised center portion  116  of a rib  110 . Raised center portion  116  is configured to lift and support the foot of the wearer further away from lower surface  122  of ribbed element  108  in the vicinity of drainage hole  112 . Lifting the foot of the wearer away from lower surface  122  enhances the ability of the water to flow underneath the foot and to drainage holes  112 . 
     In some embodiments, ribs  110  may also include provisions to control the spacing between adjacent ribs  110 . In some embodiments, ribs  110  may be contoured to widen the interstitial spacing between two adjacent ribs  110  in discrete locations along the length of ribs  110 . For example, ribs  110  that surround drainage holes  112  may be contoured to widen groove  117  in the vicinity of drainage holes  112  to enhance the ability of the drainage holes  112  to direct water away from the foot of the wearer. Such contouring may be particularly advantageous when drainage holes  112  of multiple sizes or large drainage holes  112  are used. Contouring of ribs  110  accommodates larger drainage holes  112  without increasing the overall interstitial spacing between adjacent ribs  110 . If ribs  110  are spaced too far apart, the wearer&#39;s foot may be uncomfortable. 
     Additionally, for comfort, ribs  110  may not all have the same height. In some embodiments, all ribs  110  may extend the same distance away from sole  104 . If ribs  110  include contouring as described above, all ribs  110  may have the same contouring. However, in other embodiments, some ribs  110  may extend a different distance away from sole  104  than other ribs  110 . For example, ribs  110  positioned in a forefoot portion of article of footwear  100  may extend, generally, further away from sole  104  than do ribs  110  in an arch region of article of footwear  100 . Similarly, ribs  110  in a heel region of article of footwear  100  may extend further away from sole  104  than do ribs  110  positioned in an arch region of article of footwear  100 . In some embodiments, ribs  110  positioned in the forefoot and heel regions may extend away from sole  104  the same or a similar distance. 
     This increased height of ribs  110  in the forefoot and heel regions provide additional massaging effects to the wearer&#39;s foot in these regions. When the wearer is standing or walking, the weight of the wearer tends to be on the heel or the forefoot and not, generally, in the center of the foot. Having higher ribs  110  in the forefoot and heel regions, therefore, may be more comfortable for a wearer. Additionally, if ribs  110  are integrally formed with sole  104 , as is shown in  FIGS. 10-11  and discussed in greater detail below, the manufacturing process for a single-injection molded sole may be improved by having ribs  110  of varying height. Ribs  110  in the center of the mold (i.e., ribs  110  positioned in the arch region) may be more difficult to manufacture consistently at longer lengths. Shortening ribs  110  in this portion of article of footwear  100  may yield more consistent manufacturing results during a manufacturing run. 
       FIGS. 6-8  show how one embodiment of article of footwear  100  may be used to move fluid away from a wearer&#39;s foot and to evacuate fluid from article of footwear  100 .  FIG. 6  shows a foot  120  positioned in article of footwear  100 . Article of footwear  100  is exposed to water  118 . In the example shown in  FIG. 6 , water  118  is being splashed into article of footwear  100 . In other embodiments, article of footwear  100  may be exposed to water  118  in other ways, such as raining or showering water  118  down onto article of footwear  100 , submerging article of footwear  100 , or the like. Water  118  flows into article of footwear  100 , as is indicated by the arrow in  FIG. 7 , which is the same as  FIG. 6  with foot  120  shown in phantom for clarity. Water  118  may accumulate in grooves  117 . Water  118  may reach a sufficient depth that water  118  may temporarily accumulate around foot  120  prior to evacuation. 
       FIG. 8  is a cross-sectional view of  FIG. 6  that shows the flow pattern of water  118  through article of footwear  100 . Water  118  generally enters article of footwear  100  along a periphery of foot  120 . Foot  120  is supported away from lower surface  112  of ribbed element  108  by rib  110 . In particular, foot  120  is held furthest away from lower surface  122  by raised center portion  116  of rib  110 . Due to the action of gravity and/or to movement of article of footwear  100 , water  118  flows along the contour of lower surface  122 , as indicated by the arrows, and is directed towards drainage hole  112 . Water  118  enters drainage hole  112  through hole inlet  111 , which may be formed in ribbed element  108 . Water  118  flows through or accumulates in drainage hole  112 . Some water  118  may exit drainage hole  112  via hole outlet  113 , which may be formed in outsole  106 . Water  118  may then flow away from article of footwear  100 . 
     In some embodiments, the depth of grooves  117  and drainage holes  112  may be sufficient to keep water  118  from maintaining contact with foot  120  for extended periods. In some embodiments, therefore, water  118  need not exit drainage hole  112  via hole outlet  113 , or hole outlet  113  may not be provided. Rather, a wearer may remove article of footwear  100  from foot  120  and invert article of footwear  100  to pour any accumulated water  118  out of grooves  117  and/or drainage holes  112 . 
     In some embodiments, article of footwear  100  may be configured to be completely disassembled, such as to be able to clean and/or disinfect the individual elements of article of footwear  100 . As shown in  FIG. 9 , upper  102  and ribbed element  108  may be separated from sole  104 . In a separable configuration, upper  102  and/or ribbed element  108  may be removably attached to sole  104  using any method known in the art, such as press-fitting upper  102  into grooves provided on sole  104 , with other fasteners such as hook-and-loop fasteners, or the line. In other embodiments, upper  102  and/or ribbed element  108  may be fixedly attached to sole  104 , such as by stitching, with an adhesive, or using any other method or fastening system known in the art. 
       FIGS. 10-11  show another embodiment of an article of footwear  200  having drainage features. Article of footwear  200  is similar to article of footwear  100 , in that article of footwear  200  includes an upper  202  associated with a sole  204 , where sole  204  includes drainage features. The drainage features, as shown in  FIG. 11 , include a plurality of ribs  110  disposed along a length of sole  204 . In this embodiment, drainage holes  112  are formed through sole  204  in the interstitial spaces  117  between adjacent ribs  110 . The drainage holes  112  are disposed at or near the transverse centerpoint of sole  204 . 
     In this embodiment, ribs  110  are not formed on a separate ribbed element. Instead, ribs  110  are integrally formed with sole  204  so that ribs and sole  204  are a single, unitary portion of material. Such an embodiment may be provided to reduce costs or to minimize the collection points of water in article of footwear  200 . 
     Because sole  204  is formed as a unitary portion of material in this embodiment, the materials used to form sole  204  may differ from the materials used in other embodiments. If cost reduction is a motive in making a unitary sole, the material or materials used for sole  204  may be lower in cost than in other embodiments. Also, because various features are included on sole  204 , a lower weight material may be used for sole  204  so that the weight of sole  204  does not become uncomfortable for the wearer. Finally, because many features may be included in sole  204 , the material or materials chosen for sole  204  may be selected for ease and/or consistency in manufacturing all of the features of sole  204 , including, for example, ribs  110  and drainage holes  112 . In unitary-body sole embodiments, sole  204  may be injection molded with thermoplastic polyurethane (TPU). In other embodiments, sole  204  may be made from other materials and/or formed using other manufacturing methods known in the art. 
       FIGS. 12-14  show another embodiment of an article of footwear  300  having drainage features. Article of footwear  200  is similar to articles of footwear  100  and  200 , in that article of footwear  300  includes an upper  302  associated with a sole  304 , where sole  304  includes drainage features. The drainage features, as shown in  FIGS. 13 and 14 , include a plurality of ribs  110  disposed along a length of sole  304 . In this embodiment, drainage holes  112  are formed through sole  304  in the interstitial spaces  117  between adjacent ribs  110 . The drainage holes  112  are disposed at or near the transverse centerpoint of sole  304 . 
     In addition to drainage features in sole  304 , upper  302  has also been provided with drainage features in this embodiment. As shown in  FIGS. 13 and 14 , upper  302  is split into two sections: a first section  330  and a second section  332 . First section  330  and second section  332  are configured to be removably attached to each other. This is done so that first section  330  and second section  332  may be separated, as shown in  FIG. 14 . This open configuration of upper  302  may allow article of footwear  300  to dry faster than a similar article of footwear with an upper that does not open. 
     First section  330  and second section  332  may be removably attached to each other using any method known in the art. In the embodiment shown in the figures, first section  330  is provided with a first portion  334  of a hook-and-loop fastener while second section  332  is provided with a second portion  336  of the hook-and-loop fastener configured to engage with first portion  334 . In the embodiment shown in the figures, first portion  334  is fixedly attached to an underside of first section  330  while second portion  336  is fixedly attached to an upper surface of second section  332 . When attached to each other, therefore, first section overlaps second section  332 . In other embodiments, first section  330  may be attachable to second section  332  so that little or no overlap occurs, for example, if the edges of first section  330  and second section  332  are provided with zipper teeth. In other embodiments, any type of mechanical or other type of fastener may be used, such as snaps, buttons, zippers, press-fitting elements, or magnets. 
     In addition to allowing for a faster drying time, upper  302  is also size adjustable. As shown in  FIGS. 12 and 13 , the two sections of upper  302  may be attached to each other with different amounts of overlap. Therefore, upper  302  may be adjusted to be tighter (with more overlap) or looser (with less overlap) on the wearer&#39;s foot. In addition to being able to fit a number of different users, this adjustability may also be used by a single user to accommodate different uses. For example, a wearer may find article of footwear  300  more comfortable to wear while wet if upper  302  is looser. Alternatively, a wearer may find article of footwear  300  more comfortable and secure to wear while wet if upper  302  is fitted more tightly to the foot. Having an adjustable upper such as upper  302  allows a user to select the tightness of the fit according to his or her preference. 
     Upper  302  may be provided with additional drainage features. Upper  302  as shown in the figures is a multi-layer upper. A first layer  344  is associated with a second layer  342  using any method known in the art, such as by stitching or with an adhesive. First layer  344  may be configured to contact the wearer&#39;s foot while second layer  342  may be configured to form the exterior surface of upper  302 . In some embodiments, first layer  344  may be made from a porous material so that water or other fluids may be transferred rapidly through first layer  344 . For example, first layer  344  may be made from a mesh material. 
     Second layer  342  may be made of a nonporous, water resistant, or even waterproof material. Second layer  342  may be made of such a material to increase the durability of upper  302 . Such materials may include plastics, vinyl, natural or synthetic rubber, or similar flexible but durable materials. Second layer  342  may be configured with apertures  340  in the form of holes or linear grooves configured to expose portions of first layer  344 . Apertures  340  may enhance the ability of water to enter or exit upper  302  for comfort and/or ease of drying. 
     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. 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.