Abstract:
This invention relates to an item of footwear comprising a bottom structure located between the foot and the ground, formed by several superimposed soles and one top ( 9 ), said shoe being characterized in that each of the soles is perforated and able to let water and air through, and in that each sole is made of a washable synthetic material.

Description:
[0001]    This application is a U.S. National Entry of PCT/FR2008/050765, bearing the same or similar title and having an international filing date of Dec. 11, 2008, and further claims priority to French application number 0754966, bearing the same or similar title, and filed May 10, 2007. 
     
    
     FIELD 
       [0002]    The invention concerns an item of footwear with a ventilated sole. 
       BACKGROUND 
       [0003]    The processes of walking and standing up cause the feet to swell and heat up, which usually causes pronounced discomfort as time passes. In order to reduce this discomfort, the use of adapted items of footwear and soles has been the subject of ongoing research down the years. 
         [0004]    Because of the clearly identified problem of heating, items of footwear are more and more frequently provided with perforations on the upper side. These developments, however, do not prevent significant heating of the foot on the underside, which is completely insulated from the exterior. 
         [0005]    The sole of the footwear generally contains several layers of wholly waterproof synthetic material, especially because of the need to maintain intervening spaces to absorb shocks caused by striking the ground. 
         [0006]    These shock-absorbing spaces can, for example, be cushions of air, gels kept in envelopes or specific types of polymer. 
         [0007]    Most items of footwear available today present a structure with openings allowing the instep of the foot to be aerated, while the underside is hermetically confined within the sole mould. All persons therefore encounter problems with heating of the plantar arch with the corresponding discomfort factors, namely:
       significant swelling of the foot with a sensation of excessive heat,   increased humidity and friction within the item of footwear,   increased sweating of the foot, 80% of this coming from the underside,   rapid loss of cleanness of the inner sole, with development of bacteria and odors.       
 
         [0012]    The aim of the invention is therefore to resolve these principal difficulties by proposing an item of footwear that contains not only classic aeration from the upper side, but ventilation from the normally hermetic lower part. 
       SUMMARY 
       [0013]    The present invention concerns an item of footwear containing a lower structure located between the foot and the ground, consisting of several superimposed soles and an upper part, each of the soles being perforated so as to allow air and water to pass, and made of a washable synthetic material, the superimposed soles being respectively:
       an outer sole, in contact with the ground, made of rubber and/or a rigid polymer that is good shock absorber,   an intermediate sole,   a molded, fixed inner sole that is also a shock absorber, preferably consisting of two layers
 
characterized in that the intermediate sole preferably consists of at least one, and most advantageously of the full range, of the following parts:
   one part consisting of a metallic wire netting membrane, stuck and sewn to the outer sole,   one part consisting of a meshed membrane, held together with the metallic wire netting membrane and placed above it in relation to the ground, when the two parts are assembled together. This meshed membrane is stuck and sewn to the outer sole if it is used alone.       
 
         [0019]    The term “item of footwear” must be understood to include all forms of footwear, such as sport trainers, leisure footwear or a classic shoe that may be worn together with a suit. 
         [0020]    The advantages of the item of footwear according to the invention are numerous:
       ventilation through part of the footwear prevents excessive heating of the underside and keeps humidity levels in the sole low,   the underside of the foot is kept dry and ventilated, thus allowing the walker greater comfort,   the removal of moisture both during the wearing of the footwear and during walking, and when the footwear is not being used, prevents the development of bacteria and unpleasant odors,   all the soles making up the item of footwear are washable and dry rapidly, thus making maintenance easy,   the structure of the base of the footwear, consisting of different soles made of different materials of various levels of porosity, helps keep dust and debris out of the footwear while allowing air and moisture to pass through, the multi layer structure being particularly effective in this regard,       
 
         [0026]    the footwear is adapted to consist, from the time of its manufacture, of a sole and a set of materials that helps reduce shocks, and there is therefore no need for the walker to add an additional sole, as is frequently the case currently, to provide satisfactory absorption levels for the shock that passes along the spinal column when the heel strikes the ground. 
         [0027]    Other characteristics and benefits of the invention are evident in the description that follows, with regard to the attached sketch, which is given only as a non-exhaustive example. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0028]      FIG. 1  shows a cross section of the item of footwear according to the invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0029]    The item of footwear as described below contains a lower structure, that is, one located between the foot and the ground when the footwear is worn, consisting of several superimposed layers, preferably at least three. A footwear structure produced through the assembly of several stuck or sewn layers is known in itself. The upper part of the footwear, or top of the footwear, is made according to a traditional method using pieces of textile sewn and stuck together and presenting an opening on the front face so as to allow lacing as usual. 
         [0030]    This type of footwear is shown in  FIG. 1 , with the various soles making up the invention. 
         [0031]    According to the invention, the item of footwear is characterized in that each of the soles is perforated and as such allows the passage of water and air, and in that each sole is manufactured using a washable synthetic material. 
         [0032]    The water and air can circulate as shown by the arrow in  FIG. 1 , between the exterior and interior of the footwear, and in the opposite direction, through the soles. 
         [0033]    Again according to the invention, and with reference to  FIG. 1 , the soles are arranged as follows:
       an exterior sole  1 , in contact with the ground, manufactured using a rubber and/or rigid polymer that is good shock absorber,   an intermediate sole  2 ,   an interior sole  3  that is molded and fixed and absorbs shocks, preferably consisting of two layers.       
 
         [0037]    According to the invention, the outer sole  1  contains at least two openings or slits, and preferably a range of openings and slits or smaller dimensions, the length of the said openings and slits being typically 2 to 300 millimeters and their length being limited to 8 millimeters maximum to prevent the passage of pebbles. 
         [0038]    This reduced dimension allows air and water to pass but prevents debris and gravel from blocking the openings. 
         [0039]    Preferably, the openings or slits are made in the hollow sections  4  of the outer sole  1 . 
         [0040]    The outer sole should preferably be manufactured using a rigid material resistant to abrasion, such as neoprene EVA or polyurethane, or a combination of these materials. In order to improve this resistance, the outer sole is reinforced in the areas of increased wear by rubber sections, which may also be carbon-reinforced. This composition also allows better absorption of shocks while improving durability thanks to the pieces of rubber. 
         [0041]    The geometry of the openings and slits included in the sole should preferably be defined so as to allow optimal passage of air and water while preventing pebbles and other items from penetrating through the exterior sole. The choice of geometry of the slits takes account of the natural movements of the foot, facilitation the flexion movements needed for such footwear. The geometry also takes account of the overall solidity of the sole, in order to prevent an excessive number of wrongly positioned slits from weakening the outside sole. The dimension and shape of the slits are designed to prevent tearing of the sole, which may aggravate the more the footwear is used. 
         [0042]    According to the invention, the intermediate sole  2  should preferably consist of at least one, and preferably of the full range, of the following parts:
       a part consisting of a metallic wire netting membrane, stuck and sewn to the exterior sole  1 ,   a part consisting of a meshed membrane  6  held together with the metallic wire netting membrane  5  and placed above it in relation to the ground, when the two parts are assembled together. The said meshed membrane  6  is stuck and sewn to the exterior sole  1  if it is used alone.       
 
         [0045]    The metallic wire netting membrane allows optimal passage of air and water while protecting the foot from pebbles and other outside objects. 
         [0046]    One or the other membrane is stuck to the exterior sole so that the adhesive does not cover the section of the membrane that joins up the openings and slits of the outside sole, thus preventing the membrane perforations from becoming blocked. 
         [0047]    The meshed membrane  6 , for aesthetic reasons and for protection, allows the metallic wire netting membrane to be covered while providing comfort during wearing. This intermediate sole can also, where applicable, allow pieces of latex, a gel, or other material that allows better absorption of shocks and/or distribution of shock waves, to be inserted between the two membranes, thus optimizing the comfort of the footwear. 
         [0048]    It is thus possible, according to the invention, to introduce between the metallic wire netting membrane  5  and the meshed membrane  6  an insert that allows absorption of shocks and/or distribution of shock waves. 
         [0049]    The insert should preferably be equipped with perforations to allow moisture and heat to circulate between the interior and exterior of the footwear, through the various soles. 
         [0050]    According to the invention, the interior sole  3 , in contact with the foot, contains the following layers:
       a lower layer  7 , in contact with membrane located below it, consisting of EVA,   an upper layer  8 , consisting of treated textiles on which the foot rests, this part being stuck and/or sewn onto the lower layer  7 .       
 
         [0053]    According to the invention, the upper layer  8 , consisting of textiles, is treated to reduce the formation of bacteria and odors. The treatment can be carried out after manufacture of the textile or on the textile fiber itself prior to weaving. This textile part allows the evacuation of sweat. 
         [0054]    The interior sole  3  is designed so as to improve comfort and absorption of shocks, and should preferably be molded and consist of EVA, with stuck sections consisting of latex, gel etc, according to need, in order to improve shock absorption capacity and/or comfort. It is obviously totally perforated. 
         [0055]    The upper part of the footwear, its instep  9 , is manufactured using perforated tissues manufactured from washable synthetic materials in order to allow moisture and heat to be evacuated through the upper part, in the normal way. 
         [0056]    Several variations on the item of the footwear are possible; it may contain different materials although the synthetic substances mentioned are preferable, and thickness of the various soles and the constituent layers may vary without falling outside the scope of the invention. 
         [0057]    The number and size of the perforations in each sole may be chosen from a wide range and adjusted according to the materials used; the position, geometry and size of the perforations may be made according to several different configurations without falling outside the scope of invention. 
         [0058]    The footwear may of course contain different method of lacing on its instep as well as different coverings and reinforcements, without falling outside the scope of the invention. 
         [0059]    The various soles and layers can be adjusted between each other using different techniques known in the field, without exclusion, for example by sticking or sewing. 
         [0060]    The invention is of course not limited to the methods of realization described and represented as example, but also covers all the technical equivalents and combinations thereof.