Patent Abstract:
A breathable shoe, including: an upper assembly ( 10;310;410 ) having a breathable upper ( 11;311;411 ); a membrane ( 14;314;414 ) made of a material which is waterproof and breathable, and a sole ( 16;116;216;316;416 ) made of perforated elastomer, which are all mutually attached such that the membrane is arranged between the upper assembly and the sole, and the sole is sealed perimetrically to the membrane, in a manner to prevent moisture to enter into the upper assembly from the sole through the membrane, and to permit moisture to leave the inside of the upper assembly through the membrane and through the sole. In one preferred embodiment, the membrane is first attached to the upper assembly so that the upper assembly is a unitary upper assembly including the membrane, and such unitary upper assembly is subsequently attached to the sole.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims priority to Italian Application No. PD2000A 000091, filed Apr. 13, 2000, and WIPO Application No. PCT/EP01/04050, filed Apr. 9, 2001. The present application also claims priority to the U.S. application Ser. No. 10/009,482, filed Dec. 13, 2001. The contents of these applications are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a breathable shoe.  
         [0004]     2. Discussion of the Background  
         [0005]     It is known that a shoe, in order to be comfortable, must ensure proper exchange of heat and water vapor between the microclimate inside the shoe and the external one.  
         [0006]     This exchange of heat and water vapor, however, must not compromise in any way the impermeableness of the shoe to external humidity or water.  
         [0007]     Currently commercially available shoes entrust this exchange of heat and water vapor substantially to the upper or to the sole.  
         [0008]     As regards the upper, shoes which are perforated and/or provided with linings made of a breathable and waterproof material are currently commercially available.  
         [0009]     In some models, some parts of the upper can be replaced with materials which are indeed waterproof and breathable at the same time.  
         [0010]     In rubber soles, many solutions have been proposed in order to solve the problem of the lack of breathability which is inherent in the characteristics of the material.  
         [0011]     One of these solutions, disclosed in Italian patent No. 1232798, consists in dividing the sole into two layers with through holes and in interposing a breathable waterproof membrane which is joined perimetrically and hermetically to the two layers.  
         [0012]     Variations of this solution occur in subsequent patents, all of which are in any case focused on dividing the sole into two layers in order to stop external water and dirt in a region which is as close as possible to the surface that makes contact with the ground.  
         [0013]     This entails manufacturing complications and in particular prevents the provision of particularly thin soles.  
         [0014]     In other cases, such as for example in European patent No. 275644, the entire sole is provided with through holes and is joined at the top with an upper having a bottom surface, which is entirely made of a waterproof breathable material (film of polytetrafluoroethylene porous foam) with the interposition of a protective layer made of porous material.  
         [0015]     This structure is adapted for shoes whose upper is not provided with the classic methods, such as the ones known as “Strobel”, “ideal welt” or “pre-assembled”.  
         [0016]     European patent No. 103601 also discloses a sole in which delimited regions are completely crossed through their thickness by holes and in which, in an upward region, a waterproof and breathable membrane is in contact with a substrate made of soft perforated material on which the foot rests; this solution is substantially equivalent to the preceding one and makes it impossible to apply classic methods.  
         [0017]     The sole is monolithic with the upper and the entire assembly is made of plastic and is therefore not breathable.  
         [0018]     The regions with holes are separate from the rest and are constituted by removable disks.  
         [0019]     Substantially the same situation is proposed by French patent No. 1228239, which discloses a shoe with a sole and an upper made of the same waterproof but non-breathable (plastic) material, provided with through holes (in both the sole and the upper) and, inside the upper, a bootie made of waterproof and breathable material.  
         [0020]     There is also an insole inside the bootie which is made of felt or similar material.  
       SUMMARY OF THE INVENTION  
       [0021]     The aim of the present invention is to provide a shoe with a waterproof and breathable sole which can be manufactured with the above cited classic methods (modified appropriately) and is simpler than the ones known in the state of the art.  
         [0022]     Within this aim, an object of the present invention is to provide a breathable shoe whose structure entails absolutely no constraints as regards styling and aesthetic research, allowing the greatest freedom to shoe shapes and types.  
         [0023]     Another object of the present invention is to provide a breathable shoe which is meant for both day-to-day use and for sports use.  
         [0024]     Another object of the present invention is to provide a breathable shoe whose cost is competitive with respect to the costs of known shoes.  
         [0025]     In accordance with the invention, there is provided a breathable shoe and a method for manufacturing a breathable shoe as defined in the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]     Further characteristics and advantages of the present invention will become better apparent from the description of three embodiments thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:  
         [0027]      FIG. 1  is a cross-section view of a shoe according to the invention in the assembled condition, in a first embodiment;  
         [0028]      FIG. 2  is a cross-section view of the shoe of  FIG. 1  prior to final assembly;  
         [0029]      FIG. 3  is a cross-section view of the sole of a shoe according to the invention in a second embodiment thereof;  
         [0030]      FIG. 4  is a cross-section view of the sole of a shoe according to the invention in a third embodiment thereof;  
         [0031]      FIG. 5  is a cross-section view of a shoe according to the invention in the assembled condition, in a fourth embodiment thereof;  
         [0032]      FIG. 6  is a cross-section view of the shoe of  FIG. 5  prior to final assembly;  
         [0033]      FIG. 7  is a cross-section view of a shoe according to the invention in the assembled condition, in a fifth embodiment thereof;  
         [0034]      FIG. 8  is a cross-section view of the shoe of  FIG. 7  prior to final assembly. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     With particular reference to  FIGS. 1 and 2 , a breathable shoe according to the invention comprises, in this case, an assembly  10  which wraps around the foot insertion region and is in turn composed of an upper  11  which is breathable (for example made of natural leather without sealing pigments) and is associated with a breathable or perforated lining  12  (made for example of Cambrelle).  
         [0036]     The lining  12  is associated with the upper  11  by spot-gluing, so as to not compromise breathability through said upper.  
         [0037]     The assembly  10  furthermore comprises a breathable or perforated insole  13  which is joined, by means of stitched seams  13   a,  to the edges of said upper  11  according to the manufacturing method commonly known as “Strobel” or “ideal welt”, so as to form a sack into which the assembly last, not shown in the figures, is to be inserted.  
         [0038]     The insole  13  can be made of a material which is breathable (for example natural leather) or perforated, with an optional heel seat lining made of soft leather with absorbent rubber latex.  
         [0039]     A membrane  14  made of a breathable and waterproof material, optionally coupled (so as to withstand hydrolysis without compromising breathability) to a supporting mesh  15  made of synthetic material, is associated with said insole  13  for example by spot gluing.  
         [0040]     Preferably, the mesh  15  lies below the membrane  14 .  
         [0041]     The membrane  14  can be of the type that is commercially available and commonly known by the trade-name Gore-Tex.  
         [0042]     A sole  16 , formed by a single block of elastomer with through holes  16   a  through its thickness, is joined to said upper for example by gluing (with hydrolysis-resistant adhesives) or high-frequency welding along a perimetric band and is sealed perimetrically with respect to said membrane  14 .  
         [0043]     As an alternative, direct injection of the sole  16  on the upper  11  can be provided.  
         [0044]     A protective element  17  made of a material which is hydrolysis-resistant, water-repellent, breathable or perforated is associated below said membrane  14  by spot gluing, for example by adopting a commercially available adhesive which is resistant to hydrolysis (of the kind commonly known as “hot-melt” or calendered-powder systems).  
         [0045]     The protective element  17  can be conveniently made of a material which is water-repellent and capable of drying rapidly, such as for example non-woven fabric or needled cloth.  
         [0046]     As an alternative, it is possible to provide a Kevlar or filtering fabric. Conveniently, the edge  18  of the protective element  17  lies inside the edge  19  of the membrane  14  in order to allow to form a seal with the sole  16 .  
         [0047]     As an alternative, the edge  19  of the membrane  14  can be folded around the edge  18  of the protective element  17 , or said protective element could be thinned at the edge (if it has the same perimeter as the membrane  14 ) so as to allow the penetration of the sealing adhesive between the membrane  14  and the sole  16 .  
         [0048]     The protective element  17  protects the membrane  14  from external impacts or foreign objects which might penetrate through the holes provided in the sole  16 .  
         [0049]     A breathable or perforated inner sole  20  completes the shoe.  
         [0050]     The shoe is manufactured by associating the membrane  14  and the protective element  17  with the assembly  10 , which is constituted by the upper  11  and the insole  13  (fitted on the last), and subsequently joining the sole  16 .  
         [0051]     As an alternative, the membrane  14  can be joined to the sole  16  first and then the composite element can be associated with the assembly  10 .  
         [0052]     The shoe according to the invention, as shown by the description of this first embodiment, is entirely breathable, any non-breathable regions being limited substantially to the perimetric regions of the sole, which must in any case ensure a good seal with respect to external moisture and water.  
         [0053]     With particular reference to  FIG. 3 , in a second embodiment the shoe differs from the preceding case in that the protective element, now designated by the reference numeral  117 , is sandwiched between two components  116   a  and  116   b  (which are mutually joined hermetically) into which the sole  116  is divided, each component having through holes  116   c  and  116   d.    
         [0054]     This is done if the thickness of the sole  116  is so great that it is difficult to clean it of any mud or dirt which might penetrate.  
         [0055]     Being blocked by the protective element  117 , in this case, the dirt can be released purely by virtue of the flexing of the sole, designated by the reference numeral  116 .  
         [0056]     The part above the protective element  117  of the sole  116  can act as an air chamber which increases comfort by absorbing any unevenness of the ground and increasing the ventilation of the membrane so as to rapidly dry its lower surface, when it is wet, in order to increase its breathability.  
         [0057]     With particular reference to  FIG. 4 , a shoe according to the invention, in a third embodiment, differs from the preceding cases in that the sole, now designated by the reference numeral  216 , has in its upper part a hollow region  220  which is delimited perimetrically by a border  221 .  
         [0058]     Dome-shaped protrusions  222  protrude from said hollow region  220 , are uniformly distributed and advantageously reach the same height as said border  221 .  
         [0059]     Holes  223  or channels are provided in said border and connect the region  220  to the outside.  
         [0060]     Each one of said holes  223  is inclined with respect to the ground contact plane, so that the outward part is lower than the inward part (this is done to avoid stagnation).  
         [0061]     The holes  223  can furthermore be provided with one-way valves, not shown in the figures (which allow only air to flow outward).  
         [0062]     With particular reference to  FIGS. 5 and 6 , a breathable shoe according to the invention, in a fourth embodiment, comprises in this case an assembly  310  composed of a tubular upper  311  which is breathable (for example made of natural leather without sealing pigments) which is associated with a breathable or perforated lining  312  (made for example of Cambrelle).  
         [0063]     The lining  312  is associated with the upper  311  by spot gluing, so as to not compromise breathability through said upper.  
         [0064]     A membrane  314  made of breathable and waterproof material, optionally coupled (so as to withstand hydrolysis without compromising breathability) to a supporting mesh  315  made of synthetic material, is associated with the lower part of the upper  311 , for example by spot gluing.  
         [0065]     A sole  316  made of a single block of elastomer with through holes  316   a  through its thickness is joined to said upper  311 , for example by gluing (with hydrolysis-resistant adhesives) or high-frequency welding along a perimetric band and is sealed perimetrically to said membrane  314 .  
         [0066]     As an alternative, it is possible to provide for the direct injection of the sole  316  over the upper  311 .  
         [0067]     A protective element  317  made of a material which is resistant to hydrolysis, water-repellent, breathable or perforated is associated below said membrane  314  by spot gluing, for example by adopting a commercially available adhesive which is resistant to hydrolysis (of the type commonly known as “hot-melt” or calendered-powder systems).  
         [0068]     Conveniently, the edge  318  of the protective element  317  is internal to the edge  319  of the membrane  314  in order to allow to form a seal with the sole  316 .  
         [0069]     As an alternative, the edge  319  of the membrane  314  can be folded around the edge  318  of the protective element  317  or said protective element could be thinned at its edge (if it has the same perimeter as the membrane  314 ) until it allows the sealing adhesive to penetrate between the membrane  314  and the sole  316 .  
         [0070]     The protective element  317  protects the membrane  314  against external impacts or foreign objects which might penetrate through the holes provided in the sole  316 .  
         [0071]     As an alternative, the protective element  317  can be arranged as in the second embodiment.  
         [0072]     In another alternative, the sole  316  can be provided as in the third embodiment.  
         [0073]     The shoe is manufactured by associating the membrane  314  and the protective element  317  with the assembly  310 , which is fitted on the last, and subsequently joining the sole  316 .  
         [0074]     As an alternative, the membrane  314  can be joined to the sole  316  first and then the composite element can be associated with the assembly  310 .  
         [0075]     With particular reference to  FIGS. 7 and 8 , a breathable shoe according to the invention in a fifth embodiment comprises, in this case, an assembly  410  which wraps around the foot insertion region and is in turn composed of an upper  411  which is breathable (for example made of natural leather without sealing pigments) and is associated with a breathable or perforated lining  412  (made for example of Cambrelle).  
         [0076]     The lining  412  is associated with the upper  411  by spot gluing, so as not to compromise breathability through said upper.  
         [0077]     The assembly  410  furthermore comprises an assembly insole  413  which is breathable or perforated and below which the edges of said upper  411  are folded and glued (a manufacturing method known as “pre-assembled” or “AGO”), so as to form a sack in which the assembly last, not shown in the figures, is to be inserted.  
         [0078]     The insole  413  can be made of breathable material (for example natural leather) or perforated material, with an optional heel seat lining made of soft leather with absorbent rubber latex.  
         [0079]     The assembly  410  also comprises a breathable or perforated filler layer  413   a  (made for example of felt) which is surrounded by the folded edges of the upper  411 .  
         [0080]     A membrane  414  made of waterproof and breathable material, optionally coupled (so as to withstand hydrolysis without compromising breathability) to a supporting mesh  415  made of synthetic material, is associated with said filler layer  413   a  for example by spot gluing.  
         [0081]     The mesh  415  is preferably in an upward region with respect to the membrane  414 .  
         [0082]     The membrane  414  can be of the commercially available type commonly known by the trade-name Gore-Tex.  
         [0083]     A sole  416  formed by a single block of elastomer with through holes  416   a  through its thickness is joined to said upper for example by gluing (with hydrolysis-resistant adhesives) or high-frequency welding along a perimetric band and is sealed perimetrically with respect to said membrane  414 .  
         [0084]     As an alternative, it is possible to provide for the direct injection of the sole  416  on the upper  411 .  
         [0085]     A protective element  417  made of hydrolysis-resistant, water-repellent, breathable or perforated material is associated below said membrane  414  by spot gluing, for example by adopting a commercially available adhesive which is resistant to hydrolysis (the type commonly known as “hot-melt” or calendered-powder systems).  
         [0086]     The protective element  417  can be conveniently made of a water-repellent material which is capable of drying rapidly, such as for example non-woven fabric or needled cloth.  
         [0087]     As an alternative, it is possible to provide a fabric made of Kevlar or filtering fabric.  
         [0088]     Conveniently, the edge  418  of the protective element  417  lies inside the edge  419  of the membrane  414  in order to allow to form a seal with the sole  416 .  
         [0089]     As an alternative, the edge  419  of the membrane  414  can be folded around the edge  418  of the protective element  417  or said protective element could be thinned at its edge (if it has the same perimeter as the membrane  414 ) until it allows the sealing adhesive to penetrate between the membrane  414  and the sole  416 .  
         [0090]     The protective element  417  protects the membrane  414  against external impacts or foreign objects which might penetrate through the holes provided in the sole  416 .  
         [0091]     As an alternative, the protective element  417  can be arranged as in the second embodiment.  
         [0092]     In a further alternative, the sole can be provided as in the third embodiment.  
         [0093]     The shoe is manufactured by associating the membrane  414  and the protective element  417  with the assembly  410 , constituted by the upper  411 , the assembly insole  413  and a filler layer  413   a  (mounted on the last), and subsequently joining the sole  416 .  
         [0094]     As an alternative ( FIG. 8 ), the membrane  414  can be joined to the sole  416  first and then the composite element can be associated with the assembly  410 .  
         [0095]     In practice it has been observed that the present invention has achieved its intended aim and objects.  
         [0096]     A shoe with a waterproof and breathable sole has in fact been provided by using the “Strobel”, “ideal welt”, “pre-assembled” and other classic methods (modified appropriately) in a simpler manner than shoes known in the state of the art.  
         [0097]     It should also be observed that the shoe according to the invention perfectly fulfills the need to have optimum exchange of heat and water vapor between the internal microclimate and the external one, while maintaining a complete impermeableness to water and moisture.  
         [0098]     It is observed that all this has been achieved while maintaining a shoe structure which is highly flexible and adaptable to any type of styling and to any aesthetic and economical level required by the market.  
         [0099]     It is also observed that the structure of the shoe according to the invention can be easily mass-produced, since the operations can be fully automated.  
         [0100]     It is further observed that the structure of the shoe according to the invention allows a certain flexibility as regards the association of its components, thus leading to considerable production savings in relation to its flexibility and adaptability to the various manufacturing situations and conditions.  
         [0101]     The present invention is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may furthermore be replaced with other technically equivalent elements.  
         [0102]     The material, as well as the dimensions, may be any according to requirements.

Technology Classification (CPC): 0