Waterproof and transpiring outsole

Abstract: The waterproof and transpiring outsole which is particularly useful for footgear comprises at least one outer band (2), made of rubber or of an equivalent material, the thickness whereof is crossed by microperforations (3). The outer band is coupled, with the interposition of a membrane (4) made of transpiring and waterproof material, to a corresponding inner band (8), also made of rubber or of an equivalent material. The inner band is crossed by holes (10) which communicate with the inside of the item of footgear.

Description: The present invention relates to a waterproof and transpiring outsole which is particularly useful in many types of footgear. Footgear with outsoles made of synthetic material or rubber is currently in widespread use and, although it has considerable advantages from point of view of production and economy as well as in terms of practicality in use, are affected by the disadvantage that the outsole of the foot is not allowed to transpire outward through them at all. This causes discomfort to the user or even the so-called "athlete's foot". Provided for this reason and known from EP-A-382,904 is an outsole having a transpiring and waterproof membrane interposed between a tread provided with microperforations and an upper part provided with holes. Although such known outsole is optimum for the transpiration of the foot, said outsole has been found to be affected by other disadvantages, the most significant of which is due to the fact that the microperforations of the tread are subject to rapid clogging, thus limiting or even inhibiting the flow of air. Also known from GB-A-472,955 (cf. the precharacterizing part of claim 1) is an article of footwear having an upper, an insole provided with a plurality of perforations, and a filler located between the insole and an outer sole and defining a plurality of channels at a face thereof engaging the insole. A perforated foxing extends around the outer sole, filler and upper and is connected thereto with a vulcanized bond. However, circulation of air is very limited and prone to clogging, since only some of the perforations are aligned with the channels and the perforations allow the ingress of dirt and water directly into the channels. The aim of the present invention is to provide an outsole which solves the disadvantage described above in the known art. A consequent primary object is to provide an outsole which has the same advantages as those currently commercially available. Another object is to provide an outsole which can be manufactured at low cost and can thus be marketed at a competitive price. Not least object is to increase comfort for the user. This aim, these objects and others which will become apparent hereinafter are achieved by a waterproof and transpiring outsole, as defined in claim 1. Further advantages of the invention will become apparent from the detailed description of an embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a perspective view of the outsole according to the invention; figure 2 is a sectional perspective detail view of the outsole of figure 1 in combination with an upper and inner sole of a shoe structure; figure 3 is a sectional view of the detail of figure 2. With reference to the above figures, the outsole according to the invention comprises a tread 1, made of rubber or of an equivalent material, from which two outer bands 2 extend upward perimetrically, are monolithic with the remainder and are provided with microperforations 3 which cross their thickness. Conveniently, said microperforations 3 can be arranged on all or part of the extension of each outer band 2. A transpiring and waterproof membrane 4 is arranged, according to the invention, inside each outer band 2 and is preferably constituted by a material such as the one commonly termed by the trademark GORE-TEX or by another equivalent material. The outsole furthermore comprises a foot supporting part 5, made of rubber or of an equivalent material, which is assembled to the tread 1, forming a single unit. Advantageously, the foot supporting part 5 comprises a grid of transverse partitions 6 which are separated by grooves 7. An inner band 8 extends perimetrically around the supporting part 5 and is located internally with respect to the outer band 2. The inner band 8 and the outer band 2 are coupled together at an edge 9 of the outsole. Said inner band 8 is crossed, in the regions in which it is superimposed on the bands 2, by holes 10 which eventually communicate with the inside of the item of footgear. Said holes 10 are arranged so as to be also connected to said grooves 7, so as to allow the flow of air arriving from the foot supporting part 5 as well. Said region is therefore connected to the outside by means of the holes 10, the membrane 4 and the microperforations 3. In combining the outsole in use with footgear, a transpiring insole 11 is arranged above the part 5, and an upper 12, made of transpiring material, is fixed inside the band 8 for example by means of stitches. At this point the fact should be stressed that during assembly no adhesive or other material must affect the regions provided with the microperforations 3, with the holes 10 and the regions occupied by the membrane 4. It should be furthermore noted that the tread 1, with the outer bands 2, and the foot supporting part 5, with the inner band 8, must be assembled so as to ultimately form a single unit, preventing water from seeping through the joints. An example of the technology which can be used to manufacture the outsole according to the invention is given by injection-molding. In the end, the structure is completely waterproof both in its lower part and in its lateral band region, in which transpiration is in any case allowed. Since the microperforations are arranged on the outer bands 2, they are not subject to easy clogging and the disadvantage which affects known transpiring and waterproof outsoles is thus overcome. It should be furthermore noted that while walking, the foot subjects the partitions 6 to alternating compressions and expansions, obtaining, in the regions in which the grooves 7 are connected to the holes 10, a sort of pumping effect, drawing in outside air and forcing out the air which is contained inside the item of footgear, which contains sweat and moisture. Transpiration is thus improved also by this mechanical effect caused by the foot, and the membrane 4 assumes the function of a sort of nonreturn valve for the moisture expelled outward through it. In practice it has thus been observed that the invention has achieved the intended aim and objects. The invention thus conceived is susceptible to numerous modifications and variations, within the scope of the inventive concept. All the details may furthermore be replaced with other technically equivalent elements. In practice, the materials employed, so long as compatible with the contingent use, as well as the dimensions, may be any according to the requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Waterproof and transpiring outsole comprising a tread (1), a foot supporting part (5) connected to said tread (1), at least one upwardly extending peripheral outer band (2) made of rubber or of an equivalent material, which is provided with microperforations (3) which pass through its thickness characterized in that said band (2) is coupled, with the interposition of a membrane (4) made of a transpiring and waterproof material, to a corresponding upwardly extending peripheral inner band (8), made of rubber or of an equivalent material, said outer band (2) is monolithic with said tread (1), said inner band (8) is monolithic with said foot supporting part (5), and is crossed by holes (10) a part of said holes (10) communicate with the region defined by said foot supporting part (5), and a part is connected to the inside of the item of footgear. Outsole according to claim 1, characterized in that said foot supporting part (5) comprises transverse and/or longitudinal partitions (6), said partitions (6) being separated from each other by grooves (7), said grooves communicating with said holes (10) of said upwardly extending peripheral inner band (8).

Inventors: POLEGATO MARIO, POLEGATO, MARIO
Applicants: POL SCARPE SPORTIVE SRL, POL SCARPE SPORTIVE S.R.L.
Application year: 1991
Main classification: A43B13
IPC codes: A43B13, A43B7