Waterproof shoe

A shoe comprising an inner-sole and a sole, a plurality of microholes being arranged at least through the central portion of both of them, and an inner liner of a material such as Gore-Tex, wherein, between said inner-sole and said sole, a layer is provided of a resilient material, such as corrugated felt.

The present invention provides a shoe with impermeable upper and sole 
permitting outward transpiration, namely a shoe wherein both the sole and 
the upper permit the passage of vapour caused by foot perspiration, though 
preventing external liquids from seeping through the upper's walls and the 
sole itself, wherein means are provided for facilitating air circulation 
through the walls and the sole of the shoe. 
In particular, a shoe is provided in which a transpiring and impermeable 
material, such as Gore-Tex.RTM., is used properly bonded with other layers 
of a suitable material, such as leather, rubber, polyurethane, etc., in 
order to obtain a shoe combining the advantageous characteristics of 
traditional shoes with regard to comfort, easy manufacture, etc. with the 
advantageous features of vapour permeability and liquid impermeability. 
This shoe is characterised in that, between the sole and the mid-sole, it 
comprises a layer of corrugated felt which, owing to the pressure exerted 
by the foot while walking, gets resiliently deformed while exerting a 
certain pumping action facilitating air circulation through this 
transpiring material and the sole of the shoe. 
In the shoe industry, especially in the last few years, the use of 
synthetic materials, such as rubber, polyurethane, etc. for footwear 
manufacture has asserted itself more and more. 
The use of these materials offers several advantages with regard to 
production costs, since the most complex and expensive parts, including, 
in particular, the sole, may be easily obtained, for example, by injecting 
a plastic material, in order to get well-made and extremely cheap 
products. However, these shoes, together with various advantages such as 
considerable lightness, resistance to wear, possibility of combining 
differently coloured layers, etc., present remarkable drawbacks with 
regard to hygiene. 
The upper of these shoes is usually made of a synthetic fabric, such as 
nylon, whereas the sole is made of an injected material, generally 
polyurethane or the like. 
However, the use of an impermeable material, such as polyurethane, for 
making the sole stops transpiration, thus facilitating vapour condensing 
inside the shoe, with the consequent formation of fungi and bad smells, 
whereas the fact that the upper is made of fabric permits the passage of 
liquids; therefore, in case it should rain or the road should be wet, 
water may penetrate into the shoe, thus causing considerable troubles for 
the user. 
EPA No. 0 275 644 discloses a shoe, the inside of which is coated, both on 
the sole and the upper, with a layer of Gore-Tex.RTM., in order to make 
the shoe impermeable, without, however, stopping transpiration. 
EP No. 0 382 904 discloses a shoe in which a layer of an impermeable and 
transpiring material, such as Gore-Tex.RTM., is provided between the sole 
and the inner-sole, both said sole and said inner-sole having a plurality 
of holes for permitting outward transpiration. 
The present invention falls within this field, since it provides an 
improved shoe being characterised in that it comprises, between the sole 
and the Gore-Tex.RTM. layer, a further layer made of a resiliently 
deformable material, in particular a layer of corrugated felt which, on 
getting deformed as a result of foot pressure, has a pumping effect which 
facilitates and increases air circulation through the sole, thus 
considerably increasing the benefits deriving from the use of 
Gore-Tex.RTM.. 
More particularly, the sole of the shoe according to the invention has a 
plurality of microholes and, between the sole and the layer of a 
transpiring material, a properly shaped material (for example corrugated 
felt) is provided which, on getting resiliently deformed, exerts this 
pumping action which can facilitate and increase transpiration. 
Then an object of the invention is to provide a shoe combining the 
advantageous characteristics of traditional footwear, i.e. low production 
costs, hygiene, etc., with the advantages of perfect transpiration and 
absolute liquid impermeability. 
A further object of the invention is to provide a shoe which may be 
manufactured with the traditional methods, without having to use any 
special equipment.

With reference to FIG. 1, numerals 1 and 2 indicate the upper and the sole 
of a shoe respectively. 
According to the invention, the inside of the shoe has a layer 3 made of a 
transpiring and impermeable material, in particular a material such as 
Gore-Tex.RTM., which is bonded to upper 4 and an inner-sole 5, the latter 
being provided with a plurality of holes 6. 
The upper and the inner-sole may be made, for example, of hide, leather, a 
synthetic and/or natural fabric or any other suitable material. 
Under inner-sole 5 there is provided a properly shaped layer 7, made of a 
suitable material, for example polypropylene corrugated felt, such as to 
have a certain degree of resiliency to exert, as a result of foot pressure 
when walking, a certain pumping effect which facilitates air circulation 
through the various layers forming the sole. 
The tread or outsole 8 of said sole 2 is provided with a plurality of holes 
9, for permitting the passage of water vapour being produced by foot 
transpiration from the inside of the shoe to the outside. 
Between tread 8 and felt layer 7 there is provided a further layer 10 made 
of an impermeable and transpiring material such as Gore-Tex.RTM., which 
serves to protect the felt layer against liquids which might seep through 
holes 9. 
Gore-Tex.RTM. layer 10 is properly fixed to the shoe, in particular only on 
the edge of layer 7, just to prevent glue from obstructing holes 9 and 
hindering the free passage of vapour. 
Preferably, in case of gluing a discrete number of glue dots is used, so as 
not to hinder the passage of vapour from the inside of the shoe to the 
outside. 
Furthermore, the Gore-Tex.RTM. layer may be fixed by sewing or any other 
suitable method. 
Felt 7 acts both as a deformable element, favouring the user's comfort, and 
to exert a certain pumping action, as already mentioned above. 
As a matter of fact, while walking, layer 7 gets deformed and flat, after 
which it recovers its former shape when the foot is lifted, thus exerting 
that pumping action which facilitates the passage of air through the sole, 
ensuring good ventilation. 
A shoe made of hide or leather may be manufactured with conventional 
techniques, by combining sewing and gluing methods, whereas shoes made of 
polyurethane or any other synthetic material may be manufactured with the 
common injection moulding techniques. 
A shoe is thus provided which, besides combining the advantageous 
characteristics of traditional shoes, though at the same time permitting 
the passage of water vapour from the inside of the shoe to the outside as 
well as absolute impermeability, offers the advantage of providing means 
which, by ensuring ventilation through the sole, improve this 
transpiration effect, thus increasing the user's comfort.