Patent Publication Number: US-2009223087-A1

Title: Shoe with new breathable waterproof sole

Description:
FIELD 
     The present invention relates to footwear and, in particular, related to a shoe with a new breathable waterproof sole. 
     BACKGROUND OF THE INVENTION 
     The problem of foot perspiration of the foot is known, and more particularly of perspiration of the sole of the foot, where a greater concentration of sweat glands is present. 
     The use of footwear with waterproof soles, which do not allow the foot to breathe, considerably worsens the problem of perspiration of the foot. Waterproof soles are, however, essential to ensure that the inside of the shoe remains dry. 
     Waterproof breathable soles are also known, which are provided with through holes obtained on the lower surface of the sole and which are coupled to membranes made of waterproof breathable material. 
     When the lower surface of the shoe is completely in contact with the ground; however, the passage of air along the plantar area is prevented, since said holes are obstructed by the pressure of the body. 
     Furthermore, the penetration of dirt and water into said holes can further prevent foot breathing, which makes the solutions proposed so far ineffective. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the present invention is a shoe with a new breathable waterproof sole, and with lateral holes for the passage of air. 
     A feature of the present invention is to allow the foot to breathe, particularly in the plantar area, where perspiration is greater. 
     A further feature of the present invention is to provide continuous circulation of air inside the shoe. 
     A further feature of the present invention is to prevent the penetration of water and dirt inside the shoe. 
     A further feature of the present invention is to provide maximum comfort for the user. 
     These and other direct and complementary aims have been achieved through a shoe with a new breathable waterproof sole, and also with lateral holes for the passage of air. 
     The new breathable waterproof sole includes a lower surface in contact with the ground, or tread, and an upper surface, where the foot rests, and where one or more soft insoles made of leather or fabric and polyurethane foam are positioned to ensure a comfortable walk. 
     Said tread can be smooth or grooved, depending on the intended use of the shoe. 
     Said new breathable waterproof sole is made of rubber, T.R. or other material and includes one or more niches or hollow areas obtained on said tread, preferably in the central plantar area, i.e. where the foot perspires the most. 
     At the level of each of said niches or hollow areas a plurality of through holes is provided, distributed in any desired way. 
     Each of said niches or hollow areas is suited to house an insert, having a substantially flat or curved shape, positioned so that the lower surface of the insert is preferably at the same level as the surface of the tread. 
     Said lower surface of the insert, i.e. the surface in contact with the ground, or tread, can be smooth or grooved. 
     Said insert is preferably made of rubber and includes, on its upper surface where it adheres to the sole, one or more elements in relief and/or grooves suited to define channels, the inlets of which are obtained in the outer lateral walls of the insert. 
     When the insert is fitted and adheres to the sole, inside said niche or hollow area, said channels communicate with the outside via the related inlets obtained laterally in the insert. 
     For said purpose, said niche or hollow area and said insert have preferably a width and/or length equal to the cross and longitudinal dimensions of the tread in the lower area, so that said lateral inlets communicate directly with the outside. 
     Said through holes, made in said niche or hollow area, place the inside of the shoe in communication with the inside of said channels obtained in the insert. 
     In this way, air can circulate between the outside and the inside of the shoe. To ensure that the foot can breathe and to prevent at the same time the penetration of water and dirt, a sole according to the present invention includes a layer of waterproof breathable material, which adheres to the upper surface of the sole, at least at the level of said niche or hollow area. 
     Said layer of waterproof breathable material is provided with pores, whose dimensions are such as to permit the passage of vapor but prevent the passage of impurities and liquid. 
     Said layer of waterproof breathable material is, for example, inserted in an additional niche obtained on the upper surface of said sole, at the level of the holes of said niche or hollow area. 
     Alternatively, for the passage of air between the inside and the outside of the shoe, additional channels or grooves can be provided also on the lower surface of the sole, in positions corresponding to said channels made in said insert, so as to form, as a whole, ducts with a circular section, for example, communicating with the outside. 
     According to a further embodiment of the invention, the channels or grooves for the passage of air can be provided mainly on said sole, with lateral external inlets. 
     Therefore, since said channels are never in communication with the ground, continuous circulation of air is ensured even when the sole rests completely on the ground, i.e. when the tread adheres fully to the ground. 
     In this way, the penetration of water and dirt is further limited. 
     According to an alternative embodiment, a sole according to the present invention may include one or more of said inserts, distributed on all or part of its lower surface. 
     An embodiment of a sole according to present invention further includes one or more emission valves, positioned at the level of said lateral inlets of the channels for the passage of air, i.e. between said insert and said sole. 
     Said emission valves are configured to permit the outflow of air, further limiting the penetration of water and dirt. 
     For said purpose, said emission valves preferably have a substantially cylindrical shape or are in the shape of adjacent spheres, with at least one longitudinal duct for the passage of air between the inside and the outside. Said valve comprises, once applied at least at the level of the external inlet, a sticking layer made of breathable waterproof micromesh, suited to prevent the passage of water but permit the passage of air. 
     The present invention can be applied to any type and model of shoe. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       The features of the present invention will be highlighted in greater detail by the following description with reference to the attached drawings, provided as a non-limiting example, wherein: 
         FIG. 1  shows a side view of the sole according to one embodiment of the invention, prior to application of the insert, while  FIG. 1   a  is a plan view of said insert. 
         FIG. 2  shows a cross section of an embodiment of the present invention completely assembled. 
         FIG. 3  shows a cross section of an emission valve according to an embodiment of the invention, while  FIG. 3   a  shows, in detail, the external inlet of said emission valve. 
         FIG. 4  and  FIG. 5  show, respectively, the lower surface and the upper surface of the new sole according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     In one embodiment shown in  FIG. 1 , a breathable waterproof sole (S) according to the present invention comprises one or more niches or hollow areas (Z), at least one of which is obtained preferably in the central plantar area, i.e. where the foot perspires the most. 
     Said new sole (S) also includes a plurality of through holes (F), distributed in any way at the level of said niche (Z). 
     Each of said niches or hollow areas (Z) is suited to house at least one insert (I), preferably made of rubber and made integral with the sole (S) by insertion of one or more elements in relief (I 1 , I 2 ) inside corresponding seats (A 1 , A 2 ) obtained on the lower surface of the sole (S). 
     Each of said inserts (I) comprises, disposed on its upper surface, at least one niche (D) in contact with the sole (S), provided in a position corresponding to said niche or hollow area (Z) made on the sole (S), as shown in  FIG. 2 . 
     Inside said niche (D), said insert (I) also comprises one or more elements in relief (R). 
     When said insert (I) is fitted in the corresponding niche or hollow area (Z) of the sole (S), the upper surface of said elements in relief (R) is preferably in contact with the surface of said niche or hollow area (Z). 
     In this way, said elements in relief (R) form ducts for the passage of air. 
     Turning now to  FIG. 2 , the insert (I) also comprises one or more channels or grooves (C) that place the inside of said niche (D) of the insert (I) in communication with the outside. 
     In particular, the external inlets (L) of said channels or grooves (C) are provided on the outer lateral walls of the insert (I). 
     Said through holes (F), made in the niche or hollow area (Z) of said sole (S), place the inside of the shoe in communication with the inside of said niche (D) of the insert (I), and consequently also with the inside of said channels or grooves (C). 
     This permits the circulation of air between the inside and the outside of the shoe. 
     To ensure that the foot breathes and to prevent the penetration of water and dirt, this invention also comprises a layer of waterproof breathable material (G), positioned on the upper surface of the sole (S), at least at the level of said niche (Z), i.e. above said through holes (F). 
     Said layer of waterproof breathable material (G) is, for example, inserted inside a further niche (G 1 ) disposed on the upper surface of said sole (S), at the level of the holes (F) and of the niche or lower hollow area (Z), as shown in  FIG. 5 . Alternatively, as shown in  FIG. 4 , for the passage of air between the inside and the outside of the shoe, further channels or grooves (C 1 ) can be provided also on the lower surface of the sole (S), at the level of said channels or grooves (C) provided on said insert (I), in particular on the lower surface of said niche or hollow area (Z). 
     According to another embodiment of the invention, said channels or grooves for the passage of air can be provided only on the lower surface of said sole, with lateral inlets for communication with the outside. According to the embodiment shown, the present invention may comprise several inserts (I), positioned, for example, both on the central and front plantar portion (P), and at the level of the heel (T). 
     A sole according to the present invention furthermore comprises one or more emission valves (V), shown in  FIGS. 3 and 3   a  and positioned at the level of said lateral inlets (L) of said channels or grooves (C) and (C 1 ) for the passage of air, i.e. between said insert (I) and said sole (S). 
     For said purpose, said emission valves (V), made of an elastic material, preferably have a substantially cylindrical shape or are in the shape of adjacent spheres (V 1 ), with at least one longitudinal duct (W) for the passage of air between the inside and the outside. 
     Each one of said valves (V) comprises a layer (M) made of breathable waterproof material, or micromesh, applied at least at the level of the outer inlet (E) and suited to prevent the penetration of water but permit the passage of air. 
     Each insert (I) can be provided, on its lower surface, with a smooth and/or grooved tread (Bi), as shown in  FIG. 1   a.    
     Therefore, with reference to the above description and the attached drawings, the following claims are expressed.