[0001] The present invention provides a multilayer insole comprising a layer made of a material
opposing the passage of liquids though permitting the passage of water vapour, said
material being comprised between at least a felt layer and a latex foam layer.
[0002] The insole is provided for the realisation, in particular, of arch-supports or the
like to be fitted into shoes, in order to avoid the drawbacks which may result from
foot perspiration in consequence of the prolonged use of the shoe.
[0003] In particular, this intermediate layer will be made of a material, such as GORE-TEX
(registered trademark), which is impermeable, in that it does not allow the passage
of liquids, but it allows free transpiration and the passage of vapour at least in
one direction.
[0004] This material will be joined to the outward layers by means of glue dots or proper
quilting, in order to provide an insole which can prevent or delay the formation of
fungi or odours and the stagnation of liquids in contact with the foot, and which
is cheap and easy to manufacture.
[0005] As known, the problem of foot perspiration is felt by several people, since the sweat
and moisture which form as a result of transpiration are often eliminated with difficulty,
with several drawbacks such as the formation of fungi and odours inside the shoe,
the faster wear of said shoe, as well as possible epidermis damages due to maceration.
In any case, the whole of this causes a generally uncomfortable situation for people.
[0006] This problem has sharpened in the last few years, as a result of the wider and wider
spread of shoes which are made both with natural or synthetic materials, and with
hides which, for the treatments they go through in the course of working, are less
fit for permitting good foot transpiration.
[0007] It has been tried to remedy these problems by using suitable arch-supports which
are fitted into the shoe and periodically replaced.
[0008] The use of replaceable insoles inside shoes is already known.
[0009] For example, felt insoles or the like are commonly used which are fitted into shoes
both when shoes are slightly large, to better fit them to the size of the foot, and
because felt is a sufficiently deformable material which permits the foot, even when
the shoe is new, to make a properly shaped seat for itself, so as to make the shoe
more comfortable.
[0010] In order to remedy the drawbacks due to excessive foot perspiration, insoles of this
kind have been used which are made of a suitable material, such as for example latex
foam, to which, if necessary, activated charcoal and/or other suitable substances
have been added, which can absorb the odours and the sweat produced by the foot.
[0011] These insoles, the top and bottom of which are coated with a fabric layer, are fitted
into the shoe and they act both as a filler and as a material absorbing sweat and
delaying the formation of bad smells.
[0012] However, the solution known in the art is not wholly satisfying, as even these insoles,
especially in case of abundant perspiration or prolonged and continuous use of the
shoe, since they cannot eliminate absorbed moisture, become impregnated in a more
or less short time, thus becoming practically unusable.
[0013] Therefore, a solution is still being sought to the problem caused by excessive foot
perspiration and, for this purpose, the present invention provides a multilayer insole
for the realisation of transpiring, smell preventing arch-supports to be fitted into
shoes, characterised in that it uses a material such as GORE-TEX®, actually patented
and produced by the applicant of the present invention, being fitted between at least
a layer of a soft material such as, for example, felt, and a layer, for example, of
latex foam enriched with activated charcoal.
[0014] Said material forming the intermediate layer, which permits free foot transpiration,
in that it does not oppose the passage of vapour, but stops the return of humidity,
is already known in the art, but it is used in different fields for the realisation
of coats, sports jackets and the like.
[0015] The present invention will now be described in detail, by way of example, with reference
to the only accompanying drawing, which shows a sectional view of an insole according
to the invention.
[0016] With reference to said figure, the insole comprises at least three laminar layers,
of which the intermediate layer, being shown by reference number 1, is made of a material
which can block liquids, but which permits transpiration and the passage of vapour,
specifically a layer of a material such as GORE-TEX®.
[0017] This intermediate layer, combined, if necessary, with a fine mesh of fabric or non-woven
fabric, in order to make it easier to be handled, is fitted between an upper layer
2 made of felt, for example polypropylene felt, non absorbing, and a lower layer 3,
for example of latex foam, preferably enriched with activated charcoal and antibacterial
and/or anti-fungus compounds having a deodorising effect.
[0018] Layers 1, 2 and 3 are connected by means of a discrete number of glue dots, suitably
spaced to provide good adhesion among the different materials, permitting however
free foot transpiration and, consequently, the free passage of vapour. The different
layers may also be connected by proper quilting.
[0019] The insole may be produced from continuous strips forming the three layers, which
are glued or quilted together to provide a roll! from which the arch-supports may
then be obtained, for example by die-cutting or any other known method.
[0020] The arch-supports obtained in such a way are fitted into the shoe, thus providing
the foot several beneficial and comfort functions, comprising a filling effect, with
better support of the arch of the foot, as well as a sense of heat and dryness in
winter, permitting especially the vapour produced by transpiration to pass through
felt 2, without thus causing condensation, then letting vapour reach layer 1, of a
material which is permeable to water vapour (GORE-TEX®).
[0021] Then vapour reaches lower layer 3, made of latex foam or any other suitable material,
where liquid condensation occurs, not being possible for said liquid to come into
contact with the foot again, since layer 1 is impermeable to water.
[0022] This way the foot may keep dry for a rather long period, while the activated charcoal
and the antibacterial and anti-fungus compounds enriching layer 3, for example of
latex foam, avoid the formation of bad smells and ensure the insole hygiene.
[0023] At the end of the day, said insole may be taken out of the shoe, if necessary, and
let dry, in order to be used again.
[0024] Said insole may also be washed, if the need arises.
[0025] An insole is thus provided which combines the comfort advantages of insoles known
in the art and the valuable characteristic of permitting good foot transpiration,
thus avoiding that moisture, which condenses inside the shoe, is trapped in the layer
touching the foot, which would cause a sense of discomfort.
[0026] Of course the dimensions, as well as the materials used for the outward layers, and
their number may change according to the requirements of use.
1. A multilayer insole for the realisation of transpiring arch-supports, to be fitted
into shoes, characterised in that it comprises an intermediate layer made of a material
which permits the free passage of vapour but blocks liquids, said intermediate layer
being fitted between at least a layer made of a soft and permeable non absorbing material
touching the foot, and at least a layer holding and retaining the moisture produced
by transpiration condensation.
2. The multilayer insole of claim 1, characterised in that said intermediate layer is
made of a material such as GORE-TEX®.
3. The multilayer insole of any one of the preceding claims, characterised in that the
outward layer touching the foot is made of felt or any other suitable material and
the lower outward layer is made of latex foam or other suitable material.
4. The multilayer insole of any one of the preceding claims, characterised in that said
lower outward layer is enriched with activated charcoal and/or suitable antibacterial
compounds.
5. The multilayer insole of any one of the proceeding claims, characterised in that said
layers are connected by means of discrete glue dots or proper quilting.
6. A multilayer insole for the realisation of transpiring arch-supports, as described
and illustrated.