Abstract:
An article of footwear includes a flexible cover shaped to envelope at least a portion of a wearer&#39;s foot. The cover has a sole region with inner and outer surfaces, the inner surface positioned to face the sole of the wearer&#39;s foot and the outer surface positioned to face in an opposite direction. The cover also has a plurality of apertures formed in the sole region. The article further includes a removable outsole nested within the cover. The outsole has an upper surface positioned to face the sole of the wearer&#39;s foot, a lower surface facing the inner surface of the cover sole region, and a plurality of lugs on the lower surface which protrude into the plurality of apertures.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to an article of footwear. In particular, this invention relates to an article of footwear having multiple components which can be removed or replaced as desired.  
       BACKGROUND OF THE INVENTION  
       [0002]     Footwear often serves a functional role related to a particular activity. One of the most well-known examples of footwear function is protection of a wearer&#39;s feet from the external environment. In particular, people wear shoes to protect the bottoms of their feet from the surface over which they walk. Footwear may also provide added traction as a wearer walks, support for a wearer&#39;s foot, warmth, etc. Footwear often serves these and other functions in varying degrees. For example, a person may need a relatively rugged shoe when walking outside, but only need a light slipper when walking inside.  
         [0003]     Because of the many functions that footwear serves, people often have multiple pairs of shoes designed for use in different circumstances. This is can be inconvenient. If a person expects to encounter various environments for which different shoe types may be appropriate, that person may be forced to carry one or more pairs of shoes in addition to the shoes he or she may presently be wearing.  
         [0004]     As in many fields, manufacturing presents many challenges in the footwear arts. As indicated above, a shoe often needs a rugged surface in the outsole region so as to support the wearer&#39;s foot, to provide traction and/or for durability. However, it is frequently desirable that other parts of a shoe be softer and more compliant. Because of these different requirements, shoes are often fabricated from multiple types of materials. These diverse materials are usually joined in some manner, e.g., stitching, gluing, etc. Joining different component types often requires additional manufacturing steps. Reducing the number of joining operations reduces manufacturing steps, thereby reducing cost.  
         [0005]     Disposal of worn-out shoes is another challenge in the footwear arts. At the end of a shoe&#39;s life cycle, joined components must often be separated. In particular, the different materials used to construct a shoe often have differing recycling requirements. Separating components that have been glued, stitched or otherwise bonded adds to the inconvenience and expense of recycling. When recycling is not convenient, some persons will simply dispose of shoes with non-recycled refuse. If a shoe could be more easily separated into components, people will be encouraged to recycle that shoe.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention addresses the above and other challenges. In at least one embodiment, the invention includes a shoe having several components. The wearer may separate these components and then recombine some or all of these components as desired. In one embodiment, the invention includes an article configured for placement on a foot of a human wearer. The article includes a flexible cover shaped to envelope at least a portion of the wearer&#39;s foot. The cover has a sole region with opposing inner and outer surfaces, with the inner surface positioned to face the sole of the wearer&#39;s foot. The cover also has a plurality of apertures formed in the sole region. The article further includes a removable outsole nested within the cover. The outsole has opposing upper and lower surfaces, with the lower surface facing the inner sole region surface. The outsole also has a plurality of lugs on the lower surface that protrude into the plurality of apertures.  
         [0007]     In another embodiment, the invention also includes an article configured to be placed on the foot of a human wearer. This embodiment also includes a flexible cover shaped to envelope at least a portion of the foot and having a sole region. The cover further has an upper region attached to the sole region and positioned to cover at least a portion of the top and sides of the foot. A plurality of apertures are formed in the sole and upper regions. The embodiment includes a removable outsole nested within the cover and having opposing upper and lower surfaces, as well as a plurality of lugs on the lower surface which protrude into a portion of the plurality of apertures in the cover. The embodiment further includes a removable slipper nested within the cover and having a sole and an upper, the slipper sole facing the upper outsole surface.  
         [0008]     These and other features and advantages of the present invention will be readily apparent and fully understood from the following detailed description of preferred embodiments, taken in connection with the appended drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The foregoing summary of the invention, as well as the following detailed description of preferred embodiments, is better understood when read in conjunction with the accompanying drawings, which are included by way of example, and not by way of limitation with regard to the claimed invention.  
         [0010]      FIG. 1  is an upper perspective view of an assembled shoe according to at least one embodiment of the invention.  
         [0011]      FIG. 2  is a medial side view of the assembled shoe of  FIG. 1 .  
         [0012]      FIG. 3  is a lateral side view of the assembled shoe of  FIG. 1 .  
         [0013]      FIG. 4  is a rear side view of the assembled shoe of  FIG. 1 .  
         [0014]      FIG. 5  is a front side view of the assembled shoe of  FIG. 1   
         [0015]      FIG. 6  is a top view of the assembled shoe of  FIG. 1 .  
         [0016]      FIG. 7  is a bottom view of the assembled shoe of  FIG. 1 .  
         [0017]      FIG. 8  is an upper perspective view of the cage component of the shoe of  FIG. 1 .  
         [0018]      FIG. 9  is an upper perspective “exploded” view of the insole and outsole components of the shoe of  FIG. 1 .  
         [0019]      FIG. 10  is a bottom view of the outsole component of the shoe of  FIG. 1 .  
         [0020]      FIG. 11  is a bottom view of the insole component of the shoe of  FIG. 1 .  
         [0021]      FIG. 12  is a perspective view of the slipper component of the shoe of  FIG. 1 .  
         [0022]      FIG. 13  is a bottom view of the slipper component of the shoe of  FIG. 1 .  
         [0023]      FIG. 14  is an upper perspective view of the cage component of the shoe of  FIG. 1 , with a wearer&#39;s foot shown in broken lines.  
         [0024]      FIG. 15  is an upper perspective view of the cage and outsole components of the shoe of  FIG. 1 , with a wearer&#39;s foot shown in broken lines.  
         [0025]      FIG. 16  is an upper perspective view of the slipper component of the shoe of  FIG. 1 , with a wearer&#39;s foot shown in broken lines.  
         [0026]      FIG. 17  is an upper perspective view of the cage and slipper components of the shoe of  FIG. 1 , with a wearer&#39;s foot shown in broken lines.  
         [0027]      FIG. 18  is a medial cross-section of a fully assembled shoe in a first configuration.  
         [0028]      FIG. 18A  is an enlarged portion of the cross-section of  FIG. 18 .  
         [0029]      FIG. 19  is a medial cross-section of a fully assembled shoe in a second configuration.  
         [0030]      FIG. 19A  is an enlarged portion of the cross-section of  FIG. 19 .  
         [0031]      FIG. 20  is a split view showing two alternate embodiments of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]     Embodiments of the invention address many of the challenges discussed above. In at least one embodiment, the invention includes a shoe having multiple components that are separable by the wearer. The wearer may then combine some or all of these components as the wearer chooses. In one embodiment, the shoe has a one-piece flexible outer covering that surrounds a wearer&#39;s foot and removably contains other shoe components. One of those components is an outsole, which slips inside the covering and rests in a sole region of the covering. An inner slipper component also fits within the covering, and rests upon the outsole. An insole component may also be inserted inside the covering, either within the slipper or between the slipper and the outsole.  
         [0033]      FIG. 1  is a perspective upper view of an assembled shoe  10  according to at least one embodiment of the invention. Shoe  10  is a right shoe (i.e., shaped for the right foot of a wearer). A left shoe according to the embodiment of  FIG. 1  would be substantially similar, but instead shaped for a wearer&#39;s left foot. Shoe  10  includes a one-piece perforated outer covering (or “cage”)  12 . Cage  12  generally surrounds the wearer&#39;s foot below the ankle, and has numerous apertures  22  formed in the cage surface. Contained within cage  12  is a slipper  14 . Interposed between slipper  14  and cage  12  is an outsole  16 . Outsole  16  is only slightly visible in  FIG. 1 , but is more clearly visible in subsequent figures. Outsole  16  further includes a plurality of lugs  20  that protrude through apertures  22  in the lower portion of cage  12 . Although not visible in  FIG. 1 , shoe  10  also includes an insole  18 . Insole  18 , which can be located between slipper  14  and outsole  16 , or entirely within slipper  14 , is described in more detail below and in  FIGS. 9, 11 ,  18 ,  18 A,  19  and  19 A.  
         [0034]     To facilitate understanding of the invention, different types of shading are used for various components of shoe  10  in the drawings. In particular, cage  12  is shown throughout the drawings without shading. Slipper  14  is shown throughout the drawings with a mesh pattern such as is sometimes used in other contexts to indicate a fabric surface. Outsole  16  is shown throughout the drawings with stippling. The stippling and mesh shading are added for purposes of more clearly distinguishing between components in the figures. The shading is not intended to imply limitation upon the surface texture of, or on the material that may be used to fabricate, any of these components.  
         [0035]      FIG. 2  is a medial side view of the shoe of  FIG. 1 . As partially seen in  FIG. 2 , outsole  16  (at least in the embodiment shown) rises slightly up the edges of a wearer&#39;s foot. The upper edges of outsole lip  32  (described in connection with  FIG. 9 ) are shown as hidden lines in portions of  FIGS. 1-5  and  15 .  FIG. 3  is a lateral side view of shoe  10 .  FIGS. 4 and 5  are rear and front views of shoe  10 , respectively.  FIG. 6  is a top view of shoe  10  showing the inner sole surface of slipper  14  in the heel region. As explained in more detail below, shoe  10  may alternately be configured such that insole  18  rests within slipper  14 .  FIG. 7  is a bottom view of shoe  10  showing lugs  20  protruding through apertures  22  in the sole of cage  12 .  
         [0036]      FIG. 8  is a perspective view of cage  12  only (i.e., without outsole  16 , insole  18  or slipper  14 ). Cage  12  snugly but comfortably holds a wearer&#39;s foot within shoe  10 . In at least some embodiments, and as shown in  FIGS. 14, 15  and  17 , cage  12  fully surrounds a wearer&#39;s foot except for a foot opening. As discussed in more detail below, selected components of shoe  10  may be combined into various configurations in which less than all of the components are used. In several of these configurations, cage  12  serves to hold the components together. For example, when cage  12  is worn with outsole  16  (and without slipper  14 ) as shown in  FIG. 15 , cage  12  holds outsole  16  against the sole of the wearer&#39;s foot.  
         [0037]     In at least some embodiments, cage  12  is a formed from a material which is sufficiently flexible to permit cage  12  to slip over a wearer&#39;s foot, yet sufficiently durable to withstand repeated contact with a hard surface over which a wearer may walk. In at least one embodiment, cage  12  is molded from thermoplastic polyurethane (e.g., DESMOPAN 9370 AU available from Bayer Corporation of Pittsburgh, Pa.). In some embodiments, the sole region of cage  12  is slightly thicker than the upper region (i.e., the portion of cage  12  covering the sides and top of a wearer&#39;s foot). In one embodiment, cage  12  has a thickness ranging from about 1.5 mm to about 2.0 mm in the side and upper regions, and a thickness of about 2.0 mm to about 2.5 mm in the sole region. The thickness(es) of cage  12  varies in other embodiments. In the embodiment shown, cage  12  has circular apertures  22  formed over most of its surface. In at least some embodiments, the size of the apertures ranges from about 5.0 mm in diameter to about 15.0 mm in diameter. In other embodiments, the diameters of the apertures range from about 4.5 mm to about 13.5 mm, while in other embodiments the diameters of the apertures range from about 5.5 mm to about 16.5 mm. Still other embodiments may have other sized apertures. In various embodiments, the sole region of cage  12  has between about 90 and about 95 apertures. In other embodiments, cage  12  may have about 80 to about 86 apertures in the sole region, while other embodiments may have about 99 to about 105 apertures in the sole region. Still other embodiments may have other numbers of sole region apertures. Similarly, the upper region of cage  12  has between about 230 and about 235 apertures in various embodiments. In other embodiments, cage  12  may have about 207 to about 212 apertures in the upper region, while still other embodiments may have about 253 to about 259 apertures in the upper region. Yet other embodiments may have other numbers of upper region apertures. In some embodiments, and as shown in  FIG. 8 , the number of apertures is reduced in the region near ankle collar  24 . In other embodiments, cage  12  may only have apertures formed in some or all of the sole region, in the sole region and some or all of the upper region, or in other combinations of locations.  
         [0038]      FIG. 9  is an upper perspective “exploded” view of outsole  16  and insole  18 . Outsole  16  has an upper surface  26  and a lower surface  28  ( FIG. 10 ). Except for lugs  20 , lower surface  28  contacts the inner sole region of cage  12 . A plurality of downwardly extending lugs  20  are distributed throughout lower surface  28 . When outsole  16  is placed within cage  12 , lugs  20  protrude through corresponding apertures  22  in cage  12 . The tips of lugs  20  then contact the ground when a wearer walks, providing traction. In some embodiments, only lugs  20  contact the ground when a wearer walks on a relatively hard surface. In other embodiments, both lugs  20  and portions of the outer sole region of cage  12  contact the ground when a wearer walks on a relatively hard surface. Lugs  20  and the corresponding apertures  22  through which those lugs protrude are relatively sized such that a user, when assembling shoe  10 , may push lugs  20  through their corresponding apertures by exerting moderate force upon the upper surface  26  of outsole  16 . The lugs are then frictionally retained by the peripheral edges of the respective apertures  22  through which they protrude. In some embodiments, the entire lower surface  28  has lugs  20  formed thereon. In other embodiments, lugs  20  may be formed on less then the entire lower surface, e.g., some parts of the lower surface may be smooth or otherwise lug-free. In the embodiment shown, lugs  20  are circular in shape and of several diameters. In at least some embodiments, lugs  20  range in diameter from about 6.0 mm to about 13.0 mm. In other embodiments, lugs  20  range in diameter from about 5.4 mm to about 11.7 mm, while in still other embodiments lugs  20  range in diameter from about 6.6 mm to about 14.3 mm. In yet other embodiments, lugs  20  may have other diameters. In embodiments having non-circular lugs, dimensions providing similar lug tip surface area could be used, but rounded, pointed and other types of lug tips are also within the invention. In various embodiments, outsole  16  has about 104 lugs. In other embodiments, outsole  16  may have about 90 to about 95 lugs, while other embodiments may have about 110 to about 115 lugs. Still other embodiments may have other numbers of lugs. The lugs need not be arranged in a regular pattern. To provide additional support to the wearer, certain lugs  20  in the heel region of lower surface  28  are slightly higher than lugs located elsewhere on lower surface  28 . In at least some embodiments, lugs  20  range in height (measured from where the lug intersects lower surface  28  to the ground-contacting surface of the lug) from about 3.0 mm to about 8.5 mm. In some embodiments, lugs  20  range in height from about 2.7 mm to about 7.7 mm. In other embodiments, lugs  20  range in height from about 3.3 mm to about 9.4 mm. Still other embodiments may have lugs of other heights.  
         [0039]     As indicated above, lugs  20  may have other shapes and/or sizes in other embodiments.  FIG. 20  shows two examples of alternate embodiments. The left side of  FIG. 20  shows a bottom view of the heel region of a shoe  10 ′ according to another embodiment of the invention. Cage  12 ′ of shoe  10 ′ has a plurality of square apertures  22 ′ through which square lugs  20 ′ protrude. The right side of  FIG. 20  shows a bottom view of the mid-foot and toe regions of a shoe  10 ″ according to yet another embodiment of the invention. Cage  12 ″ of shoe  10 ″ has a plurality of hexagonal apertures  22 ″ through which hexagonal lugs  20 ″ protrude. In certain embodiments, there may be more than one shape for lugs  20 . In embodiments having lugs of different size and/or shape, the corresponding holes in cage  12  could similarly have different sizes and/or shapes.  
         [0040]     As seen in  FIG. 9 , outsole  16  has a lip  32  surrounding upper surface  26 . In some embodiments, lip  32  is slightly larger in the toe and heel regions. As described in more detail below, cage  12  and outsole  16  may be worn without slipper  14 . In such a configuration, the raised toe and heel regions can provide additional protection to the wearer. Distributed across upper surface  26  are multiple depressions  34 . Depressions  34  correspond to protrusions  36  on lower surface  38  ( FIG. 11 ) of insole  18 . In one configuration, insole  18  nests within the region of outsole  16  formed by upper surface  26  and lip  32 . In this configuration, protrusions  36  fit within depressions  34 .  
         [0041]     In at least one embodiment, outsole  16  is molded from a wear-resistant material such as compression-molded rubber. Preferably, outsole  16  is formed from a single material. In certain embodiments, however, outsole  16  may be formed from multiple materials (e.g., a more wear-resistant material could be used for the ground-contacting tips of lugs  20  and a more pliable material used for other portions of the outsole). In at least one embodiment, insole  18  is molded from polyurethane.  
         [0042]      FIG. 12  is an upper perspective view of slipper  14 . In one embodiment, slipper  14  is formed a textile material. In some embodiments, one or more fabrics commonly used to form “bootie” shoe components are used. In certain embodiments, an expandable textile such as LYCRA (available from Dupont of Wilmington, Del.) or a LYCRA/neoprene combination are used. In some embodiments, slipper  14  is formed by wrapping one or more sheets of material around a last or other form and joining at one or more seams  40 . Seams  40  are joined by stitching, RF welding or other suitable technique. In some embodiments, the ankle collar  42  is sealed and/or stitched. A heel tab  44  is attached by stitching, RF welding, gluing or other suitable technique. Heel tab  44  may be formed from leather or similar material, and may include a strip (not shown) extending to the sole of slipper  14 . In other embodiments, no heel tab is included, and only a strip of leather or similar material is attached to the rear side of the slipper. FIG.  13  is a bottom view of slipper  14 . In certain embodiments, an additional traction pad  45  (shown in broken lines) may be attached to lower surface  46  so as to provide traction when walking on a slick indoor surface, as well as to prevent premature wear of lower surface  46 . Materials for such a traction pad include rubber-coated textile. In other embodiments, lower surface  46  is formed from a rubber-coated textile, or from some other durable and/or high friction material. In still other embodiments, laser etching is implemented to form a traction pad from the material in lower surface  46 .  
         [0043]     Various combinations of cage  12 , outsole  16 , slipper  14  and insole  18  provide a wearer with footwear suitable for different circumstances. In one configuration shown in  FIG. 14 , a person may wear cage  12  alone. The configuration of  FIG. 14  is useful in beach or other aquatic environments where the wearer requires some degree of sole protection and/or traction, or requires some protection for the upper part of the foot, but where apertures  22  could permit sand and other material to be easily washed from inside cage  12 .  
         [0044]     In the configuration of  FIG. 15 , a person may wear cage  12  with outsole  16 . The configuration of  FIG. 15  includes at least two variations. In one variation, outsole  16  could be included inside cage  12  without insole  18 . In another variation, insole  18  could also be included with cage  12  and outsole  16  (again, without slipper  14 ) if, e.g., the wearer desires more support in the sole region. The configuration of  FIG. 15  could also be useful in beach or other aquatic environments, but in which the wearer may require additional support, sole protection and/or traction. The configuration of  FIG. 15  is also suitable for use as a sandal type shoe.  
         [0045]     In the configuration of  FIG. 16 , a person may wear slipper  14  without cage  12  or outsole  16 . In this configuration, insole  18  may or may not be inserted inside slipper  14 . The configuration of  FIG. 16  is suitable for, e.g., indoor wear. Another configuration is shown in  FIG. 17 . In this configuration, slipper  14  (with or without insole  18  inside) is worn with cage  12  and without outsole  16 .  
         [0046]      FIG. 18  is a cross section of shoe  10  in one fully-assembled configuration. In the configuration of  FIG. 18 , outsole  16  rests on the inner sole region of cage  12 . Lugs  20  protrude through apertures  22  in the sole region of cage  12 . A limited number of lugs  20  also protrude through apertures  22  that are on or near the interface of the sole and upper regions of cage  12 . Insole  18  is nested directly on outsole  16 , with protrusions  36  resting in corresponding depressions  34 . For clarity, a small space is shown between each protrusion  36  and corresponding depression  34  in  FIGS. 18 and 18 A. In some embodiments, however, protrusions  36  and corresponding depressions  34  may be in contact. The lower surface  46  of slipper  14  then rests on insole  18 .  FIG. 18A  is an enlarged portion of the cross section of  FIG. 18 , and shows the relative arrangement of cage  12 , outsole  16 , insole  18  and slipper  14 . In at least some embodiments, depressions  34  are generally aligned with corresponding lugs  20  (as shown in  FIGS. 18 and 18 A). In other embodiments, some or all of depressions  20  do not align with corresponding lugs.  
         [0047]      FIG. 19  is a cross section of shoe  10  in an alternate fully-assembled configuration. The configuration of  FIG. 19  is generally similar to that of  FIG. 18 , except that insole  18  is contained within slipper  14 . In other words, the lower surface  46  of slipper  14  rests directly on upper surface  26  of outsole  16 . In the configuration of  FIG. 19 , the weight of a wearer (not shown) causes protrusions  36  on insole  18  to push the material of slipper  14  into depressions  34  of outsole  16 . This helps secure slipper  14  relative to outsole  16  and cage  12 .  FIG. 19A  is an enlarged portion of the cross section of  FIG. 19 , and shows the relative arrangement of cage  12 , outsole  16 , slipper  14  and insole  18 .  
         [0048]     In some embodiments, some or all of the components of shoe  10  are fabricated so as to facilitate recycling at the end of the shoe&#39;s useful life. Specifically, cage  12  is made from a first material (or combination of materials with similar recycling requirements) and outsole  16  is made from a second material (or combination of materials with similar recycling requirements). Insole  18  is also made from a single material (or combination of materials with similar recycling requirements), which may or may not be the same as that of outsole  16 . In some embodiments, slipper  14  may also be formed from a single material or from a combination of materials with similar recycling requirements. In this manner, the components of shoe  10  can be readily separated for recycling. In other embodiments, one or more of cage  12 , slipper  14 , outsole  16  and insole  18  is made from multiple materials which may not have similar recycling requirements.  
         [0049]     As previously indicated, each component may be manufactured in a variety of alternate embodiments. For example, embodiments of shoe  10  intended for lighter uses (and/or certain wearer preferences) could include a cage  12  formed from a first material that is more flexible and less wear resistant than would an embodiment intended for more rugged use (and/or other wearer preferences). Similarly, outsole  16  could be manufactured from a softer material for certain intended uses and/or wearer preferences, and/or have lugs that are smaller, shorter and/or less numerous. For more rugged conditions (and/or other wearer preferences), outsole  16  could be made from harder material and/or have larger, higher and/or more numerous lugs. Insole  18  could also be made from multiple materials depending upon the intended use(s) of the shoe or wearer preference (e.g., some wearers may prefer a softer insole, while others may prefer a harder insole). Different shapes (e.g., orthotic surfaces to closely support the foot) could also be incorporated. Slipper  14  could be made from a thinner, more lightweight material for warm weather uses, from a thicker and/or warmer material for cold weather uses, from more durable material if the shoe will primarily be worn outdoors, from a less durable but more stylish material if the shoe will predominantly be worn indoors, from different materials based on wearer preferences, etc. Cage  12 , outsole  16  and/or insole  18  may be transparent, translucent or opaque, and may be manufactured in different colors. Similarly, slipper  14  may also be manufactured in a variety of colors.  
         [0050]     Because the various components of shoe  10  can be removed and recombined as desired, components from different shoes can be further combined. For example, a person may own one pair of shoes  10  having a thicker cage  12  with no apertures in the upper, an outsole  12  with relatively long lugs, and a slipper that is made from a cold weather material. The person may then own another pair of shoes  10  having a thinner cage  12  with apertures in the upper, an outsole  12  with shorter lugs, and a slipper made from warm weather material. The person could then combine various components from the two pairs to obtain an even more specialized pair of shoes. Similarly, a person owning pairs of shoes  10  in different colors could mix components from the pairs to obtain different color combinations.  
         [0051]     While particular embodiments of the invention have been shown and described, it is recognized that various modifications thereof will occur to those skilled in the art. Therefore, the scope of the herein-described invention shall be limited solely by the claims appended hereto.