Note: Descriptions are shown in the official language in which they were submitted.
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WATERPROOFED AND VENTILATED ITEM OF FOOTWEAR
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TECHNICAL FIELD
The present invention generally relates to the technical field of
footwear, and particularly an item of footwear featuring some important
improvements in relation to the ability of allowing the perspiratory moisture
given off from the feet to pass through an outsole of the footwear which is
specifically designed to this purpose, while ensuring at the same time an
effective water-repellency.
BACKGROUND ART
There are known in the art items of footwear which comprise an
outsole made from a soling material such as rubber, or a compound mixed
with rubber, or also polyurethane or polyvinyl chloride. Such soling
materials used in the production of outsoles are capable of providing
protection, traction, durability, waterproofness and play also a role in
flexibility, stability and cushioning.
2 0 However, the outsoles made from such materials suffer from an
important disadvantage by not being permeable to the moisture which
perspires from the plantar of the feet. Since the perspiration moisture can
scarcely move away from the outsole of the footwear, it combines with the
darkness and the warmth inside the footwear to create a fertile breeding
2 5 ground for the fungi and bacteria that normally live on our skin. The
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decomposition of outer layers of the skin operated by the fungi and bacteria
produces isovaleric acid which is associated with the typical foul foot odor.
Moreover, if the perspiration moisture is not adequately removed from the
footwear, the skin of the feet macerates and even mild friction in the
footwear can cause painful blisters to appear on the skin of the feet.
To overcome this drawback and maintain the environment inside the
footwear as dry and healthy as possible, attempts have been made in order to
allow the perspiratory moisture given off from the feet to breathe not only
through the upper of the footwear, but also through the outsole of the
footwear in order to vent the moisture and cool the inside of the footwear.
Document EP 0 I 21 645 B I concerns an item of footwear aimed at
solving this technical problem. In particular, the footwear described in this
document comprises a rubber outsole with holes distributed therethrough
which are closed by small leather inserts arranged on the side intended to
face the upper of the footwear. These leather inserts are glued and/or fixed
into the holes with a suitable adhesive. The footwear is also provided with
an insole made of cork.
According to EP 0 121 645 B 1, the object of the through holes
distributed in the outsole of the footwear is to provide perspiration of
2 o moisture through the outsole. However, also the footwear disclosed in EP 0
121 645 BI suffers from some disadvantages, specifically in relation to its
manufacturing process and to its ability to ensure a durable breathability and
waterproofness.
As regards the process for manufacturing such a footwear, this
2 5 process should comprise at least a first step for producing the perforated
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outsole, a second step for gluing the leather inserts into the holes made
through the outsole and a third step for attaching the insole and the upper to
the top side of the outsole. A manufacturing process of this kind is rather
inefficient, and moreover the quality of the footwear thereby produced does
not meet the high standards which are demanded in footwear at the present
time.
In relation to the waterproofness of a footwear of this kind, it has
been found that the leather inserts which are glued into the holes provided in
the outsole of the footwear can become detached from the outsole upon
repeated bending of the outsole during the normal use of the footwear. Thus,
under rainy weather conditions water from the outside ambient can penetrate
the footwear through the holes and cause great discomfort. Moreover, no
means is provided for imparting a degree of water-repellency to the leather
inserts which are inherently hydrophilic and in a short time tend to absorb
and transmit liquid water, specially in the case the outsole of footwear
contacts a wet or muddy ground.
In connection with the breathability of the footwear of the kind
known in the art, a major drawback consists in that, eventually, the holes
made in the outsole become clogged with dirt and mud, thus they are no
2 o more capable of venting the moisture given off in perspiring from the
feet.
This drawback becomes apparent specially in the case the footwear is
intended for use in leisure time and/or sport activities, during which it
often
occures that the outsole touches a dirty or muddy ground.
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Also document WO 97/28711A addresses the task of developing a
breadable outsole for both normal and watertight footwear. According to
WO 97/2871 I A the outsole is formed of two layers with an elastic and
water vapour-permeable inner layer and an outer layer which covers less
than 70% of the inner layer.
However, the use of a footwear having such an outsole construction
would be rather uncomfortable because the outsole is no capable of
providing stability, traction and cushioning action, escpecially in the
case the footwaer is intended for leire time and/or sport activities.
Moreover, the manufacturing process of the footwear of WO 97/2871 I
A is rather inefficient and expensive.
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DISCLOSURE OF THE INVENTION
It is therefore an object of the present invention to provide an item of
footwear intended for leisure time andJor sport activities which is improved
in relation to its breathability and water-repellency.
Accordingly, this object is achieved with an item of footwear
comprising in combination:
- an outsole consisting in a monolithic piece of synthetic material and
having in its forepart at least a vent opening which is made through
the thickness of said outsole,
- a grating-like element which is set into said vent opening and acts as
a screen by separating and protecting the inside of the footwear from
the ground which comes into contact with said outsole,
- a pliable sheet insert made from a breathable and water repellent
leather material which is embedded into the outsole and is positioned
inside the outsole so as to overlie said vent opening,
- an insole made of a breathable and water-repellent leather,
leatherboard or fibreboard material, and
- an upper made of a breathable and water-repellent leather material or
2 0 a combination thereof with synthetic materials such as foam
polymers and nylon or polyester mesh bonded together in a
laminated form.
BRIEF DESCRIPTION OF DRAWINGS
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The features of the present invention will appear in the course of the
following description of an embodiment thereof chosen by way of example
and illustrated with reference to the accompanying drawings, in which:
Figure 1 is a plan view of the bottom surface with the tread pattern of
the outsole of the item of footwear according to the present invention;
Figure 2 is a longitudinal section view of the footwear according to
the present invention taken along line A-A of Figure 1; and
Figure 3 is a cross section view of the footwear according to the
present invention taken along line B-B of Figure I .
BEST MODE OF CARRYING OUT THE INVENTION
Referring to Figs. I-3 of the drawings, there is shown the item of
footwear according to the present invention, generally designated by 10. The
footwear comprises, in a manner known per se, an outsole 11 which is
produced by injection moulding and is made of a suitable soling material
such as rubber or a compound mixed with rubber, or also polyurethane or
polyvinyl chloride.
The outsole l 1 is provided in its forepart with at least one large vent
opening 12 which is made through the thickness of the outsole I 1. In each
2 0 vent opening 12 a grating-like element 13 is set which acts as a screen by
separating and protecting the inside of the footwear from the ground
contacted by the tread of outsole I 1. The grating-like element 13 is formed
of juxtaposed straight or curved, parallel or latticed bar elements 14 which
are preferably integral with the outsole I1 and are produced together
2 5 therewith by injection moulding. Alternatively, the bar elements 14 of the
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grating-like element 13 are integral with an insert (not shown) which is
adapted to be inserted into the vent opening 12 and fixed therein.
The length and width of the vent openings 12 provided in the outsole
1 I are chosen so that any dirty or muddy ground matter which may contact
the outsole 11 and enter the vent openings 12 is readily removed therefrom
by the natural occurring bending movement of the outsole I I when one
walks or runs. Therefore, the possibility that the vent openings 12 become
clogged by the ground matter is reduced to a minimum.
The outsole I I includes a pliable sheet insert I S which is made from
a suitable breathable and water-repellent material and is embedded into the
outsole 1 I . The sheet insert I S has a thickness preferably ranging from 2
to
3 mm. To ensure the breathability of the footwear, the sheet insert 15 is
positioned inside the outsole I1 so as to overlie the vent openings 12 as
shown particularly in Figs. 2 and 3 of the drawings. The sheet insert 15 is
protected from wear and damage by the screening action of the grating-like
elements 13.
As mentioned above, the material of the sheet insert 15 is selected
among breathable and water-repellent materials which are available in the
art of footwear manufacturing. Preferably, the material used for the sheet
2 0 insert 15 is water-repellent leather, i.e. leather which has been treated
so as
to improve its repellency to water.
Leather is made water-repellent by means of a process known in the
art by which the leather is coated with a protective hydrophobic, i.e. water
repellent compound which is formulated so as to have no effect on the
2 5 natural breathability of the leather. This protective coating can be
applied to
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leather at the tannery during the tanning process and the leather produced
thereby is capable of resisting absorption and transmission of liquid water.
Moreover, such treated leather has a greater strength and durability than
other known synthetic breathable and waterproof materials which are adapt
to be used in footwear manufacturing. The use of leather is also
advantageous because, as a natural material, leather is more effective in
allowing perspiration moisture to breathe than other known synthetic
materials.
The pliable sheet insert I S is fixed firmly into position inside the
1 o outsole 11 when this is produced by injection moulding. By this means, the
outsole I I is produced together with the sheet insert 15 embedded therein in
only one step and no further gluing step of the sheet insert I 5 in the
outsole
I I is required. Thus, the process for manufacturing the footwear is more
energy and cost efficient than those required for producing other known
footwear of this kind. Furthermore, an item of footwear exhibiting a higher
quality can be produced because the sheet insert 1 S is sealed along its
border
to the outsole 11, thereby ensuring a durable watertight closure along the
border of the vent openings 12.
The item of footwear according to present invention comprises also
2 o an insole 16 to which the upper 17 is attached by a stitching seam, f.i.
with a
Strobel working method, and then the insole 16 together with the upper 1 ? is
attached to the outsole Il in a manner known in the art of footwear
manufacturing.
The insole 16 is preferably made of a breathable and water-repellent
leather, leatherboard or fibreboard, and is flexible and able to absorb the
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moisture given off in perspiring from the feet. Other suitable materials for
the insole 16 are ethylene vinyl acetate, polyesters, thermoplastics,
graphite,
and foam polymers which may add cushioning and support to moisture
control. In fact, as shown in Figs. 2 and 3 of the drawings, the insole 16 is
provided with through holes 18 located in its forepart which aid to moisture
breathability of the insole. The insole 16 has a thickness generally in the
range of 1.8-2.0 mm.
The insole 16 may be suitably covered by an insock 19 to conceal
any stitches which may protrude. The insock 19 is preferably formed of
layers of different materials joined together by a stitching seam. The insock
19 comprises at least a top layer made of leather which is joined to a bottom
layer made of ethylene vinyl acetate. The insock 19 is also provided with a
heel cushioning pad 20 located in its back part which may be integral with
the bottom layer and protrude through an opening in the top layer in order to
contact the heel portion of the feet. Alternatively, the heel cushioning pad
20
may be a seperate pad which is attached to the top layer of the insock 19 and
is filled inside with a gel-like padding material. The insock 19 is also
provided with through holes 21 located in its forepart which aid to moisture
breathability of the insock.
2 0 The upper 17 of the item of footwear 10 is made from a water-
repellent and breathable material such as water-repellent leather or a
combination of materials such as water-repellent leather, foam polymers and
nylon or polyester mesh bonded together in a laminated form and capable of
ensuring in combination breathability and water-repellency to the upper.
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From the foregoing it can be readily understood that the item of
footwear according to the present invention obviates the drawbacks of other
similar footwear known in the art. In fact, the item of footwear of the
invention can be produced with a more efficient manufacturing process
which requires a less number of steps. Furthermore, the item of footwear of
the invention permits an optimum ventilation inside the footwear to be
achieved which maintains the environment around the feet cool, dry and
healthy by the use of high performance breathable and water-repellent
leather and synthetic materials in combination with a novel outsole
contruchon.
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