DESCRIPTION

The present invention refers to a sole structure for a ventilated footwear.

EP 1 300 090 discloses a ventilated walking shoe which comprises a midsole lying under the upper. Such midsole is made of felt, or other suitable natural fibres, and is capped by a perforated insole made of leather or hide; the midsole is arranged within a peripheral edge of the insole to join the latter to the upper of the shoe without any need for pre-lasting and lasting operations. A box-like rubber outsole arranged under the midsole comprises apertures in the central region of an edge portion thereof, which are covered by members of felt or natural fibres coupled to a membrane of a micro-porous, transpiring and impermeable material, or to perforated members made of leather or hide. These apertures are fully delimited by the edge of the outsole in order to prevent interruptions in the continuity of the edge itself. While proving as being particularly advantageous and effective for the ventilation of the wearer's foot, a drawback that is encountered with such prior-art solution lies in the fact that the above-cited transpiring and impermeable membrane coupled to the felt member is subjected to fatigue working cycles due to the repeated bending of the sole during walking; such fatigue cycles may quickly lead to a deterioration of the same membrane and, as a result, cause it to break down, so that the footwear item would at least partly lose its impermeable properties, with the possibility for water and mud to seep thereinto.

Another drawback connected with the above-mentioned prior-art solution lies in the fact that the tread of the footwear item is provided as a single-piece unitary construction with the box-like sole featuring the apertures in the edge portion thereof; it can be readily appreciated that this solution does not allow any modularity in the use of the sole in footwear items intended for applications different from mere walking or, anyway, using treads of different design. In fact, in the event where a manufacturer intends to make a ventilated footwear item for a use different from walking, such as for instance a footwear item for sports requiring treads of a more complicated design, he/she is obliged to produce a new box-like sole provided with both the required apertures and a tread of different design. This lack of modularity implies considerable costs due to the need of new moulds to be realized only to the purpose of manufacturing a ventilated footwear having a tread of a different design in the various sizes of the sole. Providing the box-like sole integrally with the tread as a single-piece unitary construction gives also rise to a further drawback, which consists in that it is practically impossible for the tread to be replaced in case of wearing out; this in fact can be only made by having the sole separated from the upper of the shoe. Such operation is obviously extremely complex and expensive, and it may quite easily damage or, anyway, impair the integrity and the performance abilities, such as in particular the impermeable properties, of the footwear item concerned.

WO 2008/138778 partially solves the drawback of breakage of the membranes by fatigue and modularity or replacement of the tread in case of wearing it out; however the embodiment disclosed therein has a membrane made of a micro- porous, transpiring and impermeable material outwardly arranged on each side of the midsole between an outer reinforcement member and a recessed seat at the outer surface of the midsole, so that the membranes are exposed to possible damages or obstructions due to stones, pebbles, mud or dust during walking.

The aim of. the present invention is to do away with the above-cited drawbacks of prior-art solutions by providing a sole structure for a ventilated footwear item that is effective in ensuring long-term reliability and durability. Within the above general aim, a purpose of the present invention is to provide a sole structure for a ventilated footwear wherein it is drastically reduced the possibility for one or more component parts of the ventilation system, particularly the membrane made of a micro-porous, transpiring and impermeable material, to undergo deterioration caused by the repeated bending of the sole during walking, as well as to be damaged or obstructed by stones, pebbles, mud or dust, so as to ensure to a greater extent a long-term reliability and durability of the footwear, as well as effectively preserving the impermeable and transpiring properties of the footwear for a longer time.

Another purpose is to improve the effectiveness of the ventilation inside and outside the footwear.

A further purpose of the present invention is to provide a sole structure for a ventilated footwear capable of being manufactured at competitive costs using generally and readily available tools and machinery.

According to the present invention, these purposes, as well as further purposes and advantages that will be apparent in the following description, are reached in a sole structure for a ventilated footwear as defined in the appended Claim 1.

Further features and advantages of the sole structure for a ventilated footwear according to the present invention will be more readily understood from the description of a particular, although not sole embodiment that is given below by way of non-limiting example with reference to the accompanying drawings, wherein:

- Figure 1 is a perspective view from the bottom of a sole structure according to the present invention;

- Figure 2 is an enlarged view of a portion of the sole structure of Figure 1 ; - Figure 3 is a portion of the sole structure of Figure 1 ;

- Figure 4 is a component part of the sole structure according to the invention;

- Figure 5 is a view similar to Figure 3 wherein the component part shown in Figure 4 is mounted in place;

- Figure 6 is a perspective exploded view of a sole structure according to the present invention.

With reference to the above-mentioned Figures, a structure of a sole according to the present invention is formed of a box-like sole 1 comprising a peripheral edge 5 and a plurality of channels 3 communicating with at least one first aperture 4 provided on the peripheral edge 5 preferably arranged approximately at the arch region; the purpose of the channels 3 is to promote forced circulation of the air inside the footwear during walking. An arch support or a conventional insole (not shown in the Figures) may be received and accommodated within the box-like sole 1.

The box-like sole 1 further comprises at least one recessed seat 17 arranged on the upper surface of the box-like sole 1 adjacent the first aperture 4 and adapted to accommodate valve means 18 which include a body member 19 supporting a microporous, transpiring and impermeable membrane 13, such that the channels 3 communicate with the first aperture 4 through the body member 19 and the membrane 13. The membrane 13 is thus located inside the peripheral edge 5 of the box-like sole 1 facing the aperture 4, and it is adapted to prevent water and moisture from seeping into and through the sole, while allowing air to be let into and out therethrough during walking.

The sole structure 1 further comprises a protective member 7 that is associable at the outer surface of the peripheral edge 5 and it is provided with a second aperture 9 that substantially faces the first aperture 4 when the protective member 7 is mounted onto the box-like sole 1.

It has been observed that a better ventilation effect in the footwear can be achieved when the first aperture 4 and the second aperture 9 have each an area less or equal to mm2 112 in a footwear size 42 (EUR); for footwear of different sizes the dimension of such areas are proportionally increased or decreased according to the size.

A covering member 14, such as a net, can be advantageously associable to the protective member 7 with the aim to prevent the membrane 13 from damage, obstruction or entry of foreign matters, such as stones, mud or soil, therethrough; such covering member 14 may be attached to the protective element 7 at the surface facing the peripheral edge 5 or to the outer surface of peripheral edge 5 where the first aperture 4 is provided.

Forming the sole structure according to the present invention there is also an outsole 15 provided with tread.

The sole structure may be formed in one piece, including the box-like sole 1 and the outsole 15 with tread, or in two or more pieces, as described hereinbelow.

In this case, the box-like sole 1 comprises a box-like midsole 2 provided with a peripheral edge 5 and a plurality of channels 3 arranged on the upper surface of the midsole 2 The midsole 2 is further provided with at least one recessed seat 17 arranged on the upper surface of the midsole 2 adjacent the first aperture 4; the recessed seat 17 is adapted to accommodate valve means 18 formed by a body member 19 supporting a membrane 13 made of a microporous, transpiring and impermeable material. The membrane 13 is thus located inside the midsole 2 and facing the aperture 4. The protective element 7 is associable to the peripheral edge 5 of the midsole 2 and it is provided with a second aperture 9 that substantially faces the first aperture 4 when the protective member 7 is mounted onto the midsole 2. An outsole 15 provided with tread is adapted to be associated at the lower surface of the midsole 2.

According to a preferred embodiment, the protective member 7 is overinjected during the injection moulding process on the covering member 14 and then attached to the peripheral edge of the midsole 2; subsequently the valve means 18 are accommodated into the recessed seat 17 with the membrane 13 facing the covering member 14. To the sub-assembly so obtained - formed by the midsole 2, the valve means 18 and the protective member 7 - is then joined the outsole 15 by means of any suitable method generally known in the art.

According to a further preferred embodiment, first apertures 4, each having an area less or equal to mm2 112 in a footwear size 42 (EUR), are respectively located on each side of the peripheral edge 5 approximately at the plantar-arch region and communicating with the channels 3. The protective member 7 comprises two protruding elements 8 respectively protruding from each side of the edge 5; such two protruding elements 8 are respectively provided with second apertures 9 each having an area less or equal to mm2 112 in a footwear size 42 (EUR), that are arranged so as to face the first apertures 4 when the protective member 7 is mounted onto the midsole 2. Respective valve means 18, and advantageously respective covering members 14, can be provided onto the midsole 2 and on each of the protruding elements 8. The outsole 15 wraps at least partially around the midsole 2 and substantially covers the protective member 7 leaving exposed the protruding elements 8.

Fully apparent from the above description is therefore the ability of the present invention to effectively reach the afore-cited aim, purposes and advantages, since a sole structure as described above is in fact fully capable of ensuring long-term reliability and durability particularly in regard to its capabilities of impermeability and ventilation effect.

In fact, thanks to the provision of the membrane 13 inside the box-like sole 1 , or the midsole 2, and the provision of the covering element 14 outside the box-like sole 1 , two advantages have been achieved: the first is the full protection of the membrane 13 from damages, obstructions or breakage during use of the footwear; it has to be pointed out that membrane 13 is the most fragile component part forming the ventilating arrangement whose integrity is necessary for the perfect functioning of such arrangement; the protection is further increased by the body 19 which supports and further covers and protects the membrane 13 inside the footwear. The second advantage is the effectiveness of the ventilation effect, which is increased by the chamber created between the membrane 13 and the covering element 14 which allows for an improved exchange of air both inward and outward the footwear; the preferred dimension of the areas of the first and second apertures 4, 9 further improve such exchange.

It shall be appreciated that the inventive sole structure as described above may be the subject of a number of modifications and may be embodied in a number of [alpha]i[pi]erent manners without departing from the scope of the present invention as defined in Claim 1 , as well as the materials, the shapes and the sizing of the individual component parts thereof, may each time be selected so as to more appropriately meet any specific requirements.