Transpiring sole structure for footwear

Abstract: Transpiring sole structure comprising a sole provided with holes (7, 8, 102, 202, 302, 402, 500) and means (11, 20, 107, 204 e 206, 205 e 207, 304 e 310, 305 e 311, 403 e 407, 502) which are selectively permeable to air but not to water, wherein said holes (7, 8, 102, 202, 302, 402, 500) open along all or part of the external edge of said sole (1, 2, 103, 200, 300, 400, 504) and open either into at least one cavity (25, 4, 105, 201 and 203, 301 and 303, 401) provided inside said sole (1, 2, 103, 200, 300, 400) or on the upper surface (501) of said sole (504), said means (11, 20, 107, 204 e 206, 205 e 207, 304 e 310, 305 e 311, 403 e 407, 502) which are selectively permeable to air but not to water being attached for hermetic closure of said holes.

Description: The present invention relates to a structure of a sole which allows transpiration of the item of footwear whereon it is mounted. From the European patent EP-A-0382904 a transpiring sole structure is known. composed of a tread with through holes via its thickness, which holes are closed above by a microporous membrane which is selectively permeable to air but not to water. This type of perforated sole allows the expulsion of stagnant air inside the footwear, but in actual fact its efficiency could be affected by the fact that the micro holes of the tread are subject to rapid blockage, therefore limiting or even preventing the passage of airthrough them. From the European patent EP-A-479183 another type of transpiring sole structure is known where transpiration takes place through a band extending peripherically upwards from the outer edge of the tread. In this solution provision is made for a second perforated band inside the first band, to be superimposed and attached to the latter by placing in between a microporous membrane which is selectively permeable to air but not to water This structure also has a grid of diaphragms separated by cracks, which grid, attached to the upper base of the tread, extends perimetrically with the above mentioned internal band. The grid is necessary so that the internal band communicating with the interior of the footwear also in the area of the sole of the foot ensures the passage of air coming also from the sole of the foot. The upper mounted on this sole structure must necessarily be made in a transpiring material in such a way as not to jeopardise transpiration through the portion of internal band attached thereto. In this structure moreover, although the passage of air between the interior of the footwear and the outside environment is ensured, the microporous membrane, during use, is exposed to the risk of damage when one of its parts is uncovered due to wear or breakage of the external perforated band, which represents for it the only barrier for protection against the outside. The process of manufacturing of a known this type of sole is often significantly more complex and expensive compared to normal practice. In many case furthermore perspiration is only possible by using a sole which appreciably modifies the original design of the footwear, making it of little use in areas wherein great importance is placed on the shape and outline of the footwear. FR-A-2 410 448 refers to a hollow plug-in device to be positioned on the inferior portion of the upper and closed by a net: said hollow plug-in device is neither positioned in the sole nor closed by a transpiring membrane. US-A-5 233 767 refers to a midsole including at least a plurality of plugs suitable for being deformed and a flexible, air-permeable top sole; no hole realised along sole external vertical edge, opening in at least one cavity realised inside the sole and closed by a transpiring membrane is provided. GB-A-472955 refers to an outsole whose outer band, belonging to the external vertical edge of the shoe, provides for plurality of perforations: non transpiring membrane closing said perforations is provided and almost all perforations are closed by the shoe's upper. The object of the present invention is that of remedying the problems suffered in traditional embodiments and in particular that of providing a structure of a sole which ensures efficient exchange of air between the interior of the footwear and the external environment, in any context. A further object of the present invention is that of providing a transpiring sole structure which allows protection of the delicate microporous membrane which is selectively permeable to air but not to water. Another object of the present invention is that of producing a transpiring sole structure which can be used universally far any type of upper, transpiring or non-transpiring, and far any type of sole, solid or "cellular". Yet another object of the present invention is that of providing a structure of a sole whose device far transpiration does not substantially modify either the shape or the area of intended use of the shoe itself. A further object of the present invention is that of providing a simplified transpiring sole structure, which for this reason has a low cost of manufacture. All the foregoing objects are achieved by providing the transpiring sole structure as claimed in claims 1-9. Advantageously the present invention enables a transpiring sole structure to be produced without heavily modifying the original design of the sole, instead leaving it virtually unaltered when it is a cellular sole, the cells of the cellular structure being exploited directly for insertion of the means which are selectively permeable to air but not to water, and therefore only perforation of the external edge of the sole is necessary. Perforation of the external edge of the sole allows excellent functioning of the mechanism of ventilation of the same, given that the holes cannot be clogged by dust or particles found on the ground. The possibility of attaching the membrane for closure of the holes in a vertical position inside the holes of the sole, in the case wherein the holes open into cavities of the sole, enables the thick perforated layer of the sole itself to be exploited to protect the membrane from external agents. The transpiring sole structure of the present invention can finally be applied universally to any type of sole, both a solid sole and a cellular type, and to any type of upper, in a transpiring or non-transpiring material, in that the air passes through the arch-support and the sole and does not involve the upper itself. This transpiring sole structure therefore can be used for any footwear model, from the classic type to a more sporty one. The present invention may be understood better with the aid of the description of some preferred embodiments of the invention indicated hereinbelow, which must be read with reference to the accompanying drawings, wherein: Figs. 1a and 1b show an enlarged perspective view, blown up. of the parts forming the element of the device for transpiration on insertion in the respective hole, and a schematic plan view of the sole according to a preferred embodiment. Fig. 2a shows a plan view of a transpiring sole structure according to another embodiment of the present invention; Fig. 2b shows the means which are selectively permeable to air but not to water, provided for the embodiment of Fig. 2a; Fig. 3a shows a plan view of a transpiring sole structure according to another embodiment of the present invention; Fig. 3b shows a perspective view and a sectioned plan view of the means which are selectively permeable to air but not to water, provided forthe embodiment of Fig 3a; Fig. 4a shows another transpiring sole structure in accordance with the present invention, seen in a plan view; Fig. 4b shows a sectioned view along line 4b-4b of the transpiring sole structure of Fig. 4a. Fig. 4c shows an enlarged perspective view of the means which are selectively permeable to air but not to water, provided for the embodiment of Figs. 4a and 4b; According to a first embodiment of the present invention, as illustrated in Figs. 1a and 1b, it is possible to obtain a transpiring sole structure by forming, starting from the external edge 100 of the cellular sole 103, a succession of holes 102 with a circular section which open on the external lateral wall 104 of the perimetrical cells 105 of the cellular structure so that the elements 107 with a cylindrical shape are hermetically inserted in the respective holes 102. Each element 107 comprises a hollow plug 106 having an external base 108 provided with micro holes 110 and an open internal base 112. An annular counter-plug 118 also forms part of the element 107, which is attached for water proofed closure of the internal end base 112 of each plug 106, interposing, between each plug 106 and the respective counter-plug 118, a layer 120 of material which is permeable to air but not to water, in the present case in Goretex™. Whereas the peripheral portions of the membrane are attached between the plug 106 and the corresponding counter-tap 118, the central portion of the membrane 120 itself, free from any impediment, can guarantee transpiration in optimum conditions. This solution advantageously offers the possibility of removing individually each plug from the respective housing to perform cleaning, maintenance or exchange of the assembly of the plug-layer of material which is selectively permeable to air but not to water-counter-tap, without having to intervene directly on the overall structure of the sole, and therefore eliminates the disadvantage of having to replace the entire sole in the case of blockage or malfunctioning of one of its small parts. Naturally the same principle applies to a solid sole, in which case the holes 102 open on the external lateral wall of the slot which extends parallel to the external edge of the solid sole itself. According to another possible variant, if a solid sole is used, the holes 102 can be tilted upwards and open directly on the upper surface of the sole itself. The transpiring sole structures illustrated in Figs. 2a-4c concern preferred embodiments of the invention wherein means are provided which are selectively permeable to air but not to water in the form of plugs covered in a microporous material which is permeable to air but not to water, to be inserted in a corresponding cavity provided in the internal area of the sole in such a way as to allow a water proofed closure of the internal end of the holes opening into the cavities themselves In Figs. 2a and 2b the structure of the sole 200 comprises a front cavity 201 wherein the holes 202 provided on the edge of the front part of the sole 200 open, and a rear cavity 203 wherein the holes 202 provided on the edge of the rear part of the sole 200 open. The front plug 204 and rear plug 205 have an identical outline and thickness to those of the corresponding cavities 201 and 203 and are made in a transpiring material. The external lateral walls of the front plug 204 and the rear plug 205 respectively are covered by membranes 206 and 207 respectively, selectively permeable to air but not to water, and the edges of the membranes 206 and 207 respectively realise a water proof attachment onto the external lateral walls of the cavities 201 and 203 respectively, in such a way as to close the end of the holes 202 which opens into the cavities 204 and 205 respectively. Attachment can be achieved for example by means of gluing, heat-sealing water proof stitching or by pushing the plugs 204 and 205 inside the respective housings 201 and 203 until a perfectly waterproof joint is achieved. As an alternative solution the plugs 204 and 205 can have an internally hollow structure in a material which is still transpiring or perforated. In Figs. 3a and 3b the transpiring sole structure 300 is provided with a pair of right and respectively left front cavities 301, wherein the holes 302 provided on the right and respectively left front part of the sole 300 open, and a pair of right and respectively left rear cavities 303, wherein the holes 302 provided on the right and respectively left rear part of the sole 300 open. In this case the pairs of front plugs 304 and rear plugs 305, in perforated plastic or transpiring material, are internally hollow and also have the external lateral wall 306 and 307 and the upper wall 308 and 309 open to allow the passage of air between the perforated or transpiring arch-support (not shown) and the external environment through the membrane 310 and 311 which is selectively permeable to air but not to water and which covers the same external lateral wall 306 and 307 of the aforementioned front plugs 304 and rear plugs 305. In Figs. 4a-4c the transpiring sole structure 400 of a further embodiment of the present invention comprises a cellular structure with communicating cells, the holes 402 opening on the external lateral walls of the perimetrical cells 401. In the present embodiment provision is made for insertion of a plug 403 in each cell 401, each of which plugs 403 is a hollow cube with the lateral walls 404 and the upper wall 405 open. Of all the plugs 403, only those relating to the perimetrical cells 401 of the cellular structure have the external lateral surface 406 covered with the microporous membrane 407, so as to block the entrance of external water towards the interior of the cellular structure. Also with this sole structure 400 the exchange of air via the whole sole of the foot is permitted, the structure being completed simply by placing on the sole a transpiring or perforated arch-support. Naturally, as a variant solution, the plugs 403 can also be solid but in a transpiring material, and it is also possible to leave the central cells of the cellular structure free, maintaining in any case the air exchange mechanism unaltered. What is referred in the previous embodiments must not restrict the more general principle claimed, it being possible for example for the holes to involve a portion or even the whole edge of the sole, for the shape and number of the cavities in the internal part of the sole to be different from those shown and consequently for the means which are selectively permeable to air but not to water to be different from those shown and consequently the means which are selectively permeable to air but not to water to have a different shape, structure and dimensions and such as to adapt to the cavity wherein they are inserted, without prejudice to the presence of one or more microporous membranes for closure of the holes for waterproofing the interior of the sole.

Claims: A transpiring sole structure comprising a sole (103) provided with holes (102) and means (107) which are selectively permeable to air but not to water and are attached to said holes for waterproof closure, said holes opening along all or part of the outer edge of said sole and said sole being provided inside with at least one cavity (105), in which said holes (102) open, characterised in that said means are attached inside said holes (102). The transpiring sole structure according to claim 1, characterised in that said means which are selectively permeable to air but not to water are in the form of a series of elements (107) for transpiration corresponding to said series of holes (102), each element (107) of said series of elements (107) comprising an assembly of a first, a second and a third part, said first part being in the form of a hollow plug (106) with open internal base (112) and micro-perforated external base (108), and having such a shape so as to adapt to the corresponding hole wherein it is hermetically inserted, said second part being in the form of a layer (120) of material which is selectively permeable to air but not to water, to be placed far a water proof closure of said open internal base (112), said third part being in the form of a counter-plug (118), axially open and inserted in said plug (106) to block said layer between the internal lateral wall of said plug and the external lateral wall of said counter-plug (118). A transpiring sole structure comprising a sole (200, 300, 400) provided with holes (202, 302,402) and means (204 and 206, 205 and 207, 304 and 306, 305 and 307, 403) which are selectively permeable to air but not to water, said holes opening along all or part of the outer edge of said sole and said sole being provided with at least one cavity, in which said holes open, said means selectively permeable to air but not to water being attached on the outlet of said holes for waterproof closure of said holes, and said at least one cavity being in one of the following alternative forms: i) of a front cavity (201 ) wherein the holes (202) provided on the front part of the sole (200) open, and a rear cavity (203) wherein the holes (202) provided on the heel of the sole (200) open, ii) of a pair of right and respectively left front cavities (301), wherein the holes (302) provided on the right and respectively left front part of the sole (300) open, and a pair of right and respectively left rear cavities (303), wherein the holes (302) provided on the right and respectively left rear part of the sole (300) open, characterised in that :said means which are selectively permeable to air but not to water are in the form of at least one plug (204 and 205, 304 and 305, 403) provided at said one cavity (201 and 203, 301 and 303, 401) at least, said one plug (204 and 205, 304 and 305, 403) at least having an external shape identical to said one corresponding cavity (201 and 203,301 and 303, 401) at least so as to be inserted perfectly therein, and in that the external lateral wall of said one plug (204 and 205,304 and 305, 403) at least in contact with the external lateral wall of said one corresponding cavity (201,203,301 and 303, 401) at least is covered with a microporous membrane (206 and 207, 310 and 311, 407) which is selectively permeable to air but not to water. The transpiring sole structure according to claim 3, characterised in that the at least one cavity is in the form of perimetrical cells (401) of said cellular sole (400), said series of holes (402) opening on the external lateral walls of said cells (401). The transpiring sole according to claims 3 and 4, characterised in that passages are provided through the internal lateral walls of the internal cells of the cellular structure, said passages placing said cells in direct communication one with the other. The transpiring sole according to claim 3, characterised in that said one plug (204 and 205) at least is made in a material which is permeable to air but not to water so as to allow a passage of air from and to the external environment. The transpiring sole structure according to claim 3, characterised in that said one plug (304 and 305, 403) at least is hollow internally and has at least the external lateral wall and the upper wall perforated to allow a passage of air from and to the external environment. The transpiring sole structure according to claim 3 characterised in that said membrane (206 and 207, 310 and 311, 407) which is selectively permeable to air but not to water and which covers the external lateral wall of said one plug (204 and 205, 304 and 305, 403) at least is attached to said lateral wall of said one corresponding cavity (201 and 203, 301 and 303, 401) at least by any technique, chosen from among gluing, heat sealing, water proofed stitching or waterproof thrust joint. The transpiring sole according to anyone of said claims 1-8 characterised in that an arch-support, transpiring or perforated above, is provided, attached to the sole, wherein when said arch- support is perforated, the holes must involve at least the area above said one cavity (105, 201 and 203,301 and 303,401) at least.

Inventors: ATTILIENI ATTILIO, ATTILIENI, ATTILIO
Applicants: STEFCOM SPA, STEFCOM S.P.A.
Application year: 1999
Main classification: A43B7
IPC codes: A43B7, A43B13