Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
"AERATION SYSTEM AND DEVICE FOR SHOES"
The present invention concerns an aeration system
for shoes comprising an aeration device, specifically
pumping means like a bellows pump, which constitutes a
further object of the invention.
Both hygienic and medical reasons dictate the
importance of keeping the foot dry and well aerated. Good
aeration, as well as dissipating bad smells, promotes the
evaporation of the sweat that inevitably forms, above all
in hot weather or during physical effort. The sole of the
foot is indeed one of the parts of the human body where
the sweat glands are most concentrated. The problem of
excessive sweating has become more serious with the
appearance of the rubber sole replacing the leather sole.
The rubber sole, indeed, whilst being advantageous in
terms of both heat insulation and water-proofing of the
foot and the possibility of modelling the tread to make
it grip better on the ground, is nevertheless impermeable
to air and does not allow sweat to transpire.
Various attempts have been made to solve this
problem. For example, hollow soles have been provided
comprising outside release valves, but the amount of air
exchanged is small and therefore does not allow effective
aeration of the foot. A solution that has achieved
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substantial success is the one that foresees coating the
inside of a perforated rubber sole with a microporous
membrane, thus impermeable to water but permeable to air
and sweat in the form of water vapour. However, this
solution also has some drawbacks. First of all, it is a
passive aeration system, since there is no device inside
the shoe that promotes the circulation of air. The
exchange of air only occurs when the sole is lifted from
the ground. Moreover, after a few uses the micropores can
be blocked by dust and dirt and therefore are no longer
able to carry out their aeration function.
The problem forming the bases of the present
invention is therefore that of providing an aeration
system for shoes that allows an effective and efficient
exchange of air and vapour between inside and outside of
the shoe.
Such a problem is solved by an aeration system and
device for shoes as outlined in the attached claims.
Further features and advantages of the present
invention will be better understood from the description
of some exemplary embodiments, which is given below by
way of non-limiting illustration, with reference to the
following figures:
Fig. 1 represents a plan and section view of the
sole according to the invention;
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Fig. 2 represents a section view according to the
direction II-II of Fig. 1;
Fig. 3 represents a side section view of the sole
for shoes according to the invention;
Fig. 4 represents a perspective view of the aeration
device according to the invention;
Fig. 5 represents a perspective view of the core of
the aeration device of Fig. 4;
Fig. 6 represents a plan view of the aeration device
according to a different embodiment;
Fig. 7 represents a side section view of a shoe
comprising the aeration system according to the
invention;
Fig. 8 represents an exploded perspective view of a
further embodiment of the present invention;
Fig. 9 represents a perspective view of a detail of
the embodiment of Fig. 8 in assembled condition;
Fig. 10 represents a perspective view of an insole
according to a further embodiment of the invention;
Fig. 11 represents a plan view from below of the
insole of Fig. 10;
Fig. 12 represents a front side view of the insole of
Fig. 11 according to the section XII-XII.
Fig. 13 is a planar view from below of a second
embodiment of the insole according to the invention;
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Fig. 14 represents a top perspective view of a further
embodiment of the insole of the invention;
Fig. 15 represents an exploded perspective view of a
different embodiment of the aeration device of the
invention;
Fig. 16 represents a perspective exploded view of a
further embodiment of the aeration device of the
invention;
Fig. 17 represents a perspective exploded view of yet
another embodiment of the aeration device of the
invention;
Fig. 18 represents a phantom side view of a further
embodiment of the aeration device of the invention;
Fig. 19 represents a side view of a different
embodiment of the elastic core of the invention;
Fig. 20 represents a bottom view of a further
embodiment of the elastic core of the invention;
Fig. 21 represents a phantom perspective view of an
elastic core according to the invention;
Fig. 22 represents a side view of the elastic core in
Fig. 21.
Fig. 23 represents a phantom side view of a different
version of the elastic core in Fig. 21;
Fig. 24 represents a bottom view of the elastic core
in Fig. 23.
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With reference to the figures, the aeration system
being the object of the present invention shall now be
described.
The aeration system of the invention comprises a
5 hollow sole 1, typically but not exclusively a hollow
sole made from rubber or another synthetic material. The
sole may of course also be made from leather or comprise
a leather tread.
The hollow sole 1 comprises a first cavity 2, formed
substantially at the heel area, and a second cavity 3,
positioned substantially at the sole of the foot and
defined by an edge la. Said cavities 2, 3 are open on
top, i.e. at the inside of the shoe. The first cavity 2
and the second cavity 3 are in fluid communication
through a channel 4 that is formed in the thickness of
the sole and that continues, at the second cavity 3, in a
groove 5. To the right and left of the groove 5, a
plurality of ramifications 6 project, in a substantially
transversal direction, which, similarly to the main
groove 5, extend up to the edge la.
At the distal end of said main groove 5 and of said
ramifications 6, the edge la of the sole 1 comprises
transversal holes 7, which place the cavity 3 in fluid
communication with the outside. At the mouth of the holes
7 towards the outside valve means 8 are arranged. The
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valve means 8 typically consist of a one-way valve for
shoes. This type of valve is conventional and
substantially consists of a small cylinder inside which a
flap is placed that only opens if the air flow is towards
the outside, whilst it does not allow the entry of air
from the outside. Said valve means 8 may also simply
consist of a dividing wall or membrane made from
microporous material (for example, GORETEX ), which
allows air and water to pass, but is waterproof.
An aeration device is housed in the sole 1 according
to the invention. Such an aeration device preferably
comprises pumping means 9, typically a bellows pump,
housed in the first cavity 2 of the sole 1. Such pumping
means 9 comprise a shell 10, formed from two half-shells
10a, 10b, and a distribution nozzle 11. The opening of
the nozzle 11 is placed at the channel 4. Said shell 10
is made from a plastic material that ensures a certain
degree of flexibility. Preferably, the shell 10 shall
have a Shore A hardness of over 80, more preferably equal
to or greater than 90. In a preferred version, the shell
10 shall be made from polyurethane, such as an adipate
ester polyurethane having the Shore A hardnesses outlined
above.
The shell 10 houses an elastic core 12 therein. The
main function of such an elastic core 12 is to increase
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resistance to stepping and to act as a "shock absorber".
Indeed, it has been seen that the provision of a hollow
pump without inner core at the heel leads to excessive
yielding of the footbed at that point and consequently
causes an irregular and not very comfortable gait.
Moreover, if the hollow pump collapses, it is no longer
able to recover its initial shape and the pumping
function is thus ended.
The elastic core 12 can consist of conventional
elastic means, like a spring. However, in the preferred
embodiment shown in the drawings, such an elastic core
comprises an elastic insert made from an elastomer, like
for example polyethylene. Preferably, such an elastomer
shall have a Shore D hardness of over 60, more preferably
over 80, even more preferably over 90. In another
preferred embodiment, the elastomer used for the elastic
core 12 shall have a Shore A hardness of between 15 and
30, more preferably about 20.
In order to avoid the elastic core 12 filling the
entire volume inside the shell 10, drastically reducing
the volume of air pumped, such an elastic core 12 is of a
size, in particular a thickness, such as to create a gap
between the core and the inner walls of the shell 10. In
practice, the shape of the elastic insert substantially
follows that of the shell 10, but it has smaller
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dimensions so as to create the gap described above. More
preferably, the length and width of the elastic insert
will be about 50% the length and width of shell 10.
For the same purpose, according to the preferred
embodiment shown in Fig. 5, the elastic core is
perforated on three sides, so that a network of small
channels 13, 13', 13", 13"', 13.... is formed therein.
In this way, the elastic core 12 itself forms a bellows
pump that is associated in action with that of the shell
10.
According to a particularly preferred embodiment of
the invention, the elastic core 12 and/or the shell 10
shall contain perfume. Typically, a "compound" of the
rubber/plastic material shall be made with the perfume,
which shall thus be absorbed in the material and shall be
released very gradually. Alternatively, the perfume can
be contained in microspheres arranged inside and/or
outside the elastic core 12 or on the surface of the
shell 10, so as to have an even longer-lasting release,
mediated by the mechanical action (rubbing) and not just
by the normal evaporation of the perfume.
The shell 10 preferably has substantially flat base
surfaces 14, 14' and a side surface 15 that has sides
with concave profile joined by rounded corners. This
shape allows the side surface 15 to be stiffened, keeping
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a good flexibility of the base surfaces 14, 14'. In this
way the bellows pump can easily carry out its pumping
action without collapsing, not even partially, under the
weight of the heel. In another preferred version, shown
in Fig. s 8 and 9, the shell 110 has the long sides with
a rectilinear profile and the end portions rounded.
By way of example, the shell 10 can have the
following size: about 6 cm length, about 4 cm width,
about 2 cm thickness. In this case, it has been
determined that the inventive device allows the
recirculation of about 15-17 cc air/vapour within the
shoe. Such a volume shall decrease according to the bulk
of the elastic core 12 arranged inside the shell 10, but
it shall in any case be between 5 and 10 cc.
It is understood that it may be possible to vary the
dimensions of the shell 10 according to requirements, for
example according to the type of shoe or the size.
As shown in Fig. 6, one or both of the base surfaces
14, 14' may comprise a pumping button 16 formed
integrally in the thickness of the shell 10 by shaping a
substantially C-shaped or horseshoe-shaped blind groove
17 on the base surface. In this way, the base surface 14,
14' is strengthened, since the groove 17 acts as a
reinforcing rib, without for this reason losing pumping
capacity.
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As shown in Fig. 3, according to a preferred
embodiment of the invention the second cavity 3 houses a
pad 18. Such a pad 18, which has the function of
supporting the sole of the foot increasing the comfort of
5 walking, can preferably be made from an expanded
synthetic material with open cells, like latex foam or
polyester-based expanded polyurethane. Alternatively, the
pad 18 can be made from a needled material, like a
needled non-woven fabric, preferably with continuous
10 needled thread, a needled felt or a needled synthetic
material (PE or PP). Alternatively, the pad 18 shall be
made from an elastomer in which holes or microholes shall
be made to make it porous. With the described materials,
the pad 18 shall be permeable to air/vapour and shall
contribute to the pump effect created by the pumping
means 9 arranged at the heel.
In another embodiment, shown in Fig. 8, the pad 118
shall be made from rubber or another elastomer and shall
comprise a perforated top surface 130 and a bottom
surface from which a plurality of flexible flaps 131
project. The flaps 131 may be arranged perpendicular to
the bottom surface of the pad 118 or else in an inclined
position and may have various shapes, for example with
rectilinear or curved profile, etc. The function of the
pad 118 is totally similar to the one described above
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for the pad 18, however the structure with flaps 131
allows a possible blockage of the groove 5 and/or of the
ramifications 6 to be avoided when walking.
The shape of the pad 18, 118 shall basically follow
the shape of the cavity 3 in which it is housed, but it
shall preferably have slightly smaller dimensions, so as
to create a gap along the perimeter of the cavity.
In a particularly preferred embodiment of the
invention, the pad 18, 118 shall contain a perfume. The
same technologies, per se known, described above may be
used for the elastic core 12 and for the shell 10 of the
pumping means 9.
Fig. 7 shows the section of a shoe 19 that comprises
the sole 1 according to the invention and a vamp 21. The
vamp 21 can be made from any material normally used for
shoes, even from a waterproof material.
As usual a footbed 20 is fixed on the sole 1, at the
side facing towards the inside of the shoe. Such a
footbed 20 shall preferably be a perforated footbed, so
as to promote the passage of air/vapour. In any case, it
must be a breathable footbed. It is also important that
the footbed 20, if coupled with the sole by gluing, be
fixed just along the edges, to avoid the layer of glue
compromising the breathability of the footbed 20.
If desired, this footbed 20 may also comprise a
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perfume, as described above, or a sanitising,
antibacterial substance, etc. The technology of the
microspheres may be particularly preferred in this case.
In the preferred embodiment of Fig. 7, the vamp
comprises a breathable layer 22 of air/vapour-permeable
material therein. Such a material can generally be one of
the materials described above for the pad 18 and can
possibly contain a perfume or a sanitising or
antibacterial substance.
The inner side of said breathable layer 22 may, in
turn, be coated with a thin layer of skin or another
finishing material for shoes.
Fig. s 8 and 9 show a different embodiment of the
sole 1 of the invention. The sole comprises a base body
101 on which an insole 132 is housed. The insole 132 is
arranged on an impression 133 formed on the top surface
of the base body 101 and having a shape matching that of
the bottom surface of the insole 132.
In turn, the insole 132 comprises a first cavity
102, arranged at the area of the heel, and a second
cavity 103, arranged at the area of the sole of the foot,
such cavities being totally similar to the cavities 2, 3
described for the embodiment of Fig. 1. A channel 104
joins the first cavity 102 with the second cavity 103. A
second channel 134 places the second cavity 103 in
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communication with the outer edge of the insole 132 and
therefore, through the corresponding hole 135a arranged
on the side surface of the base body 101, with the
outside. A further channel 136, together with the hole
135b arranged on the side surface of the base body 101,
in the heel area, places the first cavity 102 in
communication with the outside.
The sole 1 also in this case comprises an aeration
device. Such an aeration device, as described above,
preferably comprises pumping means 109, typically a
bellows pump, housed in the first cavity 102 of the
insole 132. The pumping means 109 comprise a shell 110,
also formed from two half-shells as described previously,
in which an elastic core 112 totally similar to the one
described previously is housed. The elastic core 112
shall therefore also have a plurality of channels 113,
113', 11311, 1131", 113" " formed therein. The shape of
the shell 110 and, correspondingly, of the elastic core
112 is as stated different to that of the shell 10 and of
the elastic core 12 described previously, but the latter
may be used irrespectively.
The shell 110 also comprises two nozzles 111a, 111b
arranged at the two ends, intended to align with the
channels 104, 136 that place the first cavity 102 in
communication with the second cavity 103 and with the
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outside, respectively. The shell 110, on the joining line
of the two half-shells, also has a projecting edge 137,
intended to rest on a step 138 formed along the side
walls of the first cavity 102.
In a particular embodiment, at the nozzles 111a,
111b and therefore at the hole 135b and the channel 104,
respectively, valve means 108a, 108b shall be arranged,
preferably consisting of a one-way valve as described
above. The valve means 108a can allow just the entry of
air from the outside, whereas the valve means 108b shall
allow the air sucked in to be sent to the second cavity
103 and from here, through the holes of the pad 118,
inside the shoe. This solution shall be particularly
useful in hot weather conditions, since it allows fresh
air to be introduced inside the shoe, avoiding
overheating of the foot and thus increasing the feeling
of comfort. Alternatively, preferably in cold weather
conditions, the valve 108a shall just allow foul air to
be ejected to the outside from inside the shoe, whereas
the inner valve 108b shall allow the foul air to be
sucked in from the cavity 103 and therefore from inside
the shoe. In this way a forced circulation of air around
the foot will be always obtained, without however
injecting cold air that would cause excessive cooling of
the foot. This solution, which we can define "winter
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system" in contrast with the so-called "summer system"
described above, may be obtained by simply mounting the
valve means 108a, 108b in inverted position or even more
simply by inverting the positioning of the pumping means
5 109.
In this embodiment, unidirectional valve means 108c
are also preferably arranged at the channel 134 and the
hole 135a, which for example shall allow air to be sucked
in from the outside in the "summer system" and foul air
10 to be ejected in the "winter system" described above.
It should be noted that the provision of the channel
134 and of the hole 135a, to place the second cavity 103
in communication with the outside, is not necessary and
can therefore be omitted, so as to allow just the
15 exchange of air between the second cavity 103 and the
inside of the shoe.
Advantageously, a pad 18, 118 is housed in the
second cavity 103 as described previously.
A perforated footbed 20 can advantageously be
arranged on the insole 132.
Figures 10, 11 and 12 show a different embodiment of
the present invention. The figures show an insole 232 to
be inserted on a base body 101 of a sole suitably
arranged and carrying a matching impression on top.
The insole 232 is integral and comprises a thickened
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rear portion 232a, corresponding to the heel region, and
a front portion 232b carrying a plurality of through
holes.
The rear portion 232a comprises an opening 240
intended to house the pumping means 209, similar to those
described above and thus consisting of a shell 210 in
which an elastic core 212 is housed. The shell 210,
formed from two half-shells, has a raised edge 237 and a
nozzle 211 that constitutes the air inlet/ejection
opening in the area where they meet. The raised edge 237
snap inserts into a suitable groove 241 formed along the
side wall of the opening 240. The elasticity of the
elastomeric material from which the insole 232 is made
allows its deformation and therefore the insertion or
removal of the pumping means 209.
As shown in Fig. 12, the shell 210 projects on top
and below from the thickness of the insole 232, so as to
promote the pumping action while walking.
As shown in Fig. 11, the bottom surface of the
insole 232 has a plurality of ridges 242 defining empty
spaces that, overall, form an air chamber between the
bottom surface of the insole 232 and the inner surface of
the sole on which the insole rests. Again on the bottom
surface of the insole 232, at the area where the nozzle
211 of the pumping means 209 is arranged, two ribs 243a,
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243b are arranged that go for a first portion
substantially parallel and then diverge until they reach
the edge of the insole. Such ribs 243a, 243b constitute a
channel for the air sucked in/ejected through the hole
244 arranged on the side edge of the insole 232. At such
hole 244, the bottom surface of the insole 232 further
comprises a seat 245 for valve means of the type
described above.
In an embodiment not shown, the shell 210 shall be
similar to the shell 110 and shall thus be equipped with
two nozzles, the first nozzle 211 facing towards the
inside and the second nozzle at a channel communicating
with the outside in the region of the heel.
Unidirectional valve means shall preferably be positioned
at the nozzles; this embodiment is therefore similar to
that which has been outlined above for the embodiment of
Fig. 8 and shall not be described any further. In this
case, the opening 244 and the relative unidirectional
valve means can also be omitted.
The use of the insole 232 can also avoid the
positioning of a footbed 20 inside the shoe.
Fig. 13 and 14 show further embodiments of an insole
332 or 423 according to the invention.
The insole 332 has the function of a footbed and
then replaces the latter in a shoe. The insole 332 can be
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thus adapted to any shoe, which will not require to be
arranged for receiving the insole. As will be better
understood from the description below, the aeration
device coupled to the insole 332 will not require any air
intake or vent, either inwardly or outwardly,
respectively, since it will cause an inner air
circulation of a sufficient amount to promote the removal
of sweat, while maintaining foot thermostatting.
Similarly to what has been described in relation
with the insole in Fig. 10, the insole 332 is integrally
formed, and comprises a thickened rear portion 332a,
corresponding to the heel region, and a front portion
332b carrying a plurality of through holes.
The rear portion 332a comprises an opening 340
intended to house pumping means similar to those
described above and thus consisting of a shell with an
elastic core being housed therein.
A preferred embodiment of pumping means 309 suitable
for the insole 332 is shown in Fig. 15. The shell, formed
by two half-shells 310a, 310b has, in the area where they
meet, a raised edge 337 and a nozzle 311 which is the air
inlet/ejection port. The raised edge 337 snap inserts
within a suitable groove 341 that is formed along the
side wall of opening 340. The elasticity of the
elastomeric material from which the insole 332 is made
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allows the latter to be deformed, and thus the insertion
or removal of the pumping means 309. The shell 310
projects on top and below from the thickness of the
insole 332, so as to promote the pumping action while
walking.
An elastic core 312 is housed within the shell,
which in this embodiment is elongated cap-shaped, the
support edge 350 thereof being interrupted by a series of
notches 351. The notches 351 have the function of
promoting the displacement of the material when the core
is pressed, and the subsequent elastic return thereof.
In a preferred embodiment, the notches 351 will have a
greater depth at the bent ends of the core 312, and a
lower depth at the long sides, such as to give more
resistance and elastic return to the core 312.
Preferably, the elastic core 312 is made of a SBS
elastomer (Stirene-Butadiene-Stirene) admixed with
stirene polymers or of a SEBS elastomer (Stirene-
Ethylene-Butylene-Stirene) admixed with polyolefins such
as polypropylene (PP), polyethylene (PE) or ethylene
vinyl acetate (EVA) or of the same polyurethane material
as described above with respect to the shell. Preferably,
these elastomer compounds have a Shore A hardness (after
3 seconds) ranging between 40 and 70, more preferably
between 40 and 65 (ISO 868).
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A suction/delivery cannula 352 for the air is
associated with the nozzle 311.
As shown in Fig. 13, the lower surface of insole 332
is run through by a longitudinal channel 353 that starts
5 from the opening 340, at the area in which the pumping
means nozzle 311 is positioned, and runs to the tip of
insole 332. In the first length, the channel 353 acts as
a seat for the cannula 352 of the pumping means 309,
whereas in the second length, at the foot sole area, it
10 opens into a plurality of branches 354, which are
substantially fish-bone arranged and accommodate the
through holes 355 that communicate with the upper surface
of insole 332.
Fig. 14 shows a different embodiment of an insole
15 432 according to the invention, which is also designed to
be universally used, like insole 332, with those shoes
that are not arranged to receive an aeration system.
In this case, unlike the insole 332, the pumping
means 309 will be received by the upper surface of insole
20 432. To the purpose, the upper surface 432' will
comprise, in the heel area (which is thickened to the
purpose) a seat 440 for the pumping means 309. The seat
440 is blind, such as to have a bottom surface that acts
as a support for the pumping means, and comprises, along
the side surface thereof, a groove 441 for snap-
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engagement with the raised edge 337 of shell 310. From
the seat 440 there starts a longitudinal channel 453,
which is intended to accommodate the cannula 352 of the
pumping means 309. The channel 453 opens into a recessed
chamber 456 in which a pad 18, 118 can be housed, as set
forth above.
Both the insole 332 in Fig. 13 and the insole 432 in
Fig. 14 may comprise, on the upper surface thereof that
is intended to come in contact with the foot, a finishing
layer of fabric, leather or other suitable material, duly
drilled in order to allow the air to pass therethrough.
In a particularly preferred embodiment of the
invention, the insole 332, 432 and the pumping means
thereof are integrally made, such that the raised edge
337 of the latter results to be drowned in the insole
material.
Fig. 16 shows a different embodiment of the pumping
means according to the invention. In this embodiment, the
shell comprises two half-shells 410a, 410b which are
totally similar to those described above, except for two
nozzles 411a, 411b being arranged along the raised edge
437 in a diametrally opposite position. One-way valves
453', 453" of the type described above are associated
with the nozzles 411a, 411b. The front valve 453',
associated with the nozzle 411a in which the cannula 352
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is inserted, will be generally mounted such as to allow
the air to be delivered by the pumping means 409 to the
foot sole, while the rear valve 453" will be mounted in
the opposite direction, such as to allow only the suction
of air from the heel area. The embodiment in Fig. 16 has
been specifically designed for summer use, or however in
hot climates. In fact, the external air is sucked from
the outside through the slit provided between the heel
and shoe instep and is thus fed into the shoe, thus
aerating the latter. Under cold climate conditions, this
would lead to an excessive cooling of the foot. On the
contrary, the embodiment in Fig. 15 allows the
circulation of the same air being within the shoe, thus
obtaining a good thermostatting, while causing a
turbulence suitable to keep the foot dry.
Fig. 17 shows a further embodiment of the aeration
device of the invention. The pumping means 509 comprise
two half-shells 510a, 510b having a raised edge 537, a
nozzle 511, with which a cannula 352 can be associated,
and elastic means 512 consisting of a spring. Of course,
the version similar to that in Fig. 16 can be also
provided, i.e. the summer version with two nozzles
provided with unidirectional valves. The inward face of
half-shells 510a, 510b has holding ridges 560, 560'
intended to act as a stop for both ends of the spring.
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The elastic means 512 preferably consist of a
helical spring developing substantially in a truncated-
cone shape with elongated annular profile.
According to a particularly preferred embodiment, as
shown in Fig. 21, the elastic means consist of a flexural
spring 912 consisting of an elongated annular base 975
and a treading plate 976, which are joined to each other
by means of pantograph-shaped bending elements 977, 977'.
The bending elements 977, 977' are >-shaped and <-shaped,
respectively, and consist of a lower arm 977a, 977a' and
an upper arm 977b, 977b' . The bending elements 977, 977'
are arranged in an inversed position, i.e. the first
bending element 977 originates from a first rectilinear
side 978 of the base 975, at a first end of base 975, and
develops like > until it is connected to a first end of
the treading plate 976; on the contrary, the second
bending element 977' originates from a second side 978'
of base 975, at a second end of base 975 opposite to said
first end, and develops like < until it is connected
proximate to a second end of the treading plate 976.
The treading plate 976 comprises, along both
rectilinear sides, rectangular notches having a
complementary shape to that of the upper arms 977b, 977b'
of the bending elements 977, 977', of which the function
is to allow the complete bending of the upper arms 977b,
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977b' . For the same reason, the respective lower arms
977a, 977a' are laterally fastened relative to the
rectilinear sides 978, 978' of base 975, such as to avoid
interfering therewith during bending.
Preferably, the flexural spring 912 is made of
polymeric material. More preferably, said polymeric
material will have a bending resistance ranging between
850 and 1100 Kgf/cm2 (ASTM D790) and a bending modulus
ranging between 24000 and 28000 Kgf/cm2 (ASTM D790) . Most
preferably, the polymeric material will be an acetal
polyoxymethylene copolymer having about 950 Kgf/cm2
bending resistance and about 26000 Kgf/cm2 bending
modulus.
In Fig. 22 is shown a different embodiment of the
flexural spring 912, in which, below the treading plate
976 is provided an elastic cylinder 1000. The elastic
cylinder 1000 is hollow, such as to form a tubular
structure and is made of an elastomer, such as
polyethylene. Preferably, such an elastomer shall have a
Shore D hardness of over 60, more preferably over 80,
even more preferably over 90. In another preferred
embodiment, the elastomer used for the elastic cylinder
1000 shall have a Shore A hardness of between 15 and 30,
more preferably about 20.
The upper end of the elastic cylinder 1000 is housed
CA 02582825 2007-03-23
in a suitable annular seat 999 formed on the lower face
of the treading plate 976, such as to be held therein. To
the purpose, the elastic cylinder 1000 can advantageously
be fixed, for example, by gluing to the annular seat 999.
5 The function of the elastic cylinder 1000 is both of
allowing a better elastic return of the spring 912 even
after long treading cycles, and increasing the comfort of
walking.
Fig. 18 shows a different embodiment of a shell 609
10 in which the elastic core 312 can be seen. As in the
above versions, the shell consists of two half-shells
610a, 610b that are coupled to form a raised edge 637
along which a nozzle 611 is placed (the summer version
with two nozzles and the unidirectional valves can be
15 provided also in this case). In this embodiment, however,
the upper half-shell 610a has a convex portion 670a, and
a flat portion 670b. The convex portion is intended to
protrude on top of the insole 332, 432, thereby being an
operating push-button for the pumping means 609. This
20 embodiment is conceived for a women or child shoe,
wherein the heel portion is less extended and thus
requires, also for walking comfort purposes, a small-
sized operating push-button for the pump. The version in
Fig. 18 has the purpose of reducing the size of the
25 operating push-button, without substantially reducing the
CA 02582825 2007-03-23
26
volume of pumped air, and thus the efficacy of the
pumping means 609.
Fig. 19 shows, on the other hand, a different
embodiment of the elastic core 712 according to the
invention. Also in this case, the elastic core 712 is
elongated cap-shaped, but instead of the notches, it has
a plurality of holes 780 in the vicinity of the contour
thereof, such as to create as many air vents when the
pumping means are being pressed. The elastic core 712 can
be advantageously made of the same materials as described
above for the embodiment in Fig. 15.
Fig. 20 is a bottom view of an elongated cap-shaped
elastic core 812 entirely similar to the variant in Fig.
15, though comprising, on the lower surface thereof, a
series of reinforcement ribs 890. It may happen, indeed,
that the elastic core tends to lose its elastic return
feature due to continued treading. This drawback can be
overcome, either by increasing the thickness of the piece
(which is normally 1-2 mm), with the risk of stiffening
it too much, or introducing the ribs 890.
In all the variants shown above, the shell 10, 110,
210, 310, 410, 510, 610 has a height ranging between 8
and 20 mm, preferably between 10 and 14 mm, most
preferably about 12 mm and is however structured such as
to project above the insole plane by 3-6 mm. This can be
CA 02582825 2007-03-23
27
obtained either by providing the two half-shells
symmetrically shaped, i.e. having the same height (for
example, 6 mm the lower half-shell and 6 mm the upper
half-shell) or by coupling a higher half-shell with a
less projecting one (for example, 8 mm and 12 mm,
respectively).
In a particularly preferred embodiment of the
present invention, the footbed 20 and/or the vamp 21
and/or the insole 332, 432 shall comprise a phase-change
material. Phase-change materials, known with the acronym
PCM, are materials able to pass from solid state to
liquid state and vice-versa when a particular temperature
is reached that falls within the range of weather
conditions of common use, in particular for an item of
clothing. Such weather conditions, in the case of a shoe,
correspond to a temperature in the order of 25 -30 C.
PCMs exploit the physical principle that when a material
changes its physical state, it maintains the temperature
equivalent to its melting point until all of the material
has changed state. If the material melts after the
climatic temperature has risen, it absorbs heat, vice-
versa if it solidifies following cooling, it releases
heat and by doing so maintains its temperature constant.
It is thus clear that by inserting a PCM in a shoe, it
shall take care of avoiding overheating or cooling of the
CA 02582825 2007-03-23
28
foot, absorbing the excess heat from inside the shoe or
releasing heat in the case of external cooling.
PCMs used for the purpose of the present invention
consist of mixtures of paraffins having different melting
points and high heat of fusion, encapsulated in
microcapsules that are used to coat a substrate or to be
included in said substrate. In particular, the material
used is known as Outlast Thermocules. Preferably, the PCM
shall be present at least on the face of the footbed 20
and/or of the vamp 21 facing towards the foot.
The use of a PCM in the present invention is of
particular value. Indeed, the active air circulation
system described above has the limitation of only
providing efficient ventilation during walking, whereas
in still conditions it is reduced to a passive system. In
these conditions a heating or cooling of the foot could
therefore occur, according to the weather conditions. The
phase-change material thus takes care of keeping the
temperature of the foot constant when not moving. On the
other hand, the use of just PCM, without the active
ventilation system, would not be sufficient: as stated
above, the ability of the PCM to keep the temperature
constant runs out when all of the material has changed
phase, and therefore lasts a limited amount of time. In
the present case, when walking once again, the active
CA 02582825 2007-03-23
29
ventilation system of the invention takes care of
thermostatting the shoe and regenerating the PCM, i.e.
heating the inside of the shoe in cold weather and
cooling it down in hot weather. It goes without saying
that with the alternation of stopping and moving, typical
of normal daily use of the shoe, the system of the
present invention allows perfect thermostatting.
The aeration system of the invention works in the
following way.
The inside of the shoe is in fluid communication,
through the perforated footbed 20, with the cavities 2,
102 or opening 209 and cavities 3, 103 of the sole and
therefore, through the holes 7, 135a, 135b, 244 and the
valve means 8, 108a, 108c, 245, with the outside. In the
embodiment of Fig. 7, a further way of communication with
the outside consists of the breathable layer 22 that
allows air to enter/exit from the instep of the shoe, as
shown by the arrows.
In practice, in each step the first thing to be
placed down is the heel, therefore the pumping means 9,
109, 209 are compressed causing a flow of air/vapour from
the first cavity 2, 102 or opening 209 to the second
cavity 3, 103 and then towards the outside. Then the sole
of the foot is placed down, with relative compression of
the pad 18, 118 and further pushing of air/vapour
CA 02582825 2007-03-23
towards the outside. When the heel (first) and the sole
of the foot (after) are raised, the aeration device -
pumping means 9, 109, 209 and pad 18, 118 - causes a
sucking of air/vapour from inside the shoe 19, through
5 the holes of the footbed 20, as schematised by the
arrows. A continuous and consistent air circulation is
thus created, which has the effect of taking away sweat,
keeping the foot dry, and of thermostatting the inside of
the shoe, avoiding overheating of the foot above all in
10 hotter weather and/or during physical effort.
In the embodiment of Fig. 8 and 9, the presence of
the unidirectional valves 108a, 108b, as explained above,
according to weather conditions, allows air to be taken
in just from the outside and the circulation of such air
15 inside the shoe; or else, in cold weather, the air
present in the shoe to be ejected to the outside without
substantial intake from the outside.
The insoles 332, 423 shown in Fig. 13 and 14, as
stated above, are universal, i.e. they can be inserted in
20 place of the footbed in any shoe, without requiring any
pre-arrangement. Therefore, the individual air-exchange
point with the external environment is the shoe neck. The
operation of the device is, however, completely similar
to that described above.
25 The advantages of the aeration system of the
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31
invention are clear and in part have already been
highlighted in the description above.
The aeration system of the invention, in practice,
constitutes an active and not passive system. Indeed, the
air/vapour is not simply vented through aeration holes,
as in many solutions of the prior art, but a sort of
forced circulation is created that substantially
increases the efficiency of aeration.
The aeration device - pumping means 9, 109, 209 and
pad 18, 118 - acts as a lung, taking in and letting out
air/vapour in each step, thus the volume of circulated
fluid is high.
As well as the effect of keeping the foot dry and
thermostatted, the preferred provision of perfume in a
slow-release form allows the problem of bad smells to be
solved for a long if not indefinite time.
The combination of the active ventilation system of
the invention and a phase-change material (PCM) allows
the advantages of the invention to last longer even when
not walking.
The aeration device, i.e. the pumping means 9, 109,
209 and the pad 18, 118, also acts as a shock absorber,
above all thanks to the provision of the elastic core 12,
112, 212 inside the pumping means 9, 109, 209. In this
way, the pumping effect is also associated with
CA 02582825 2007-03-23
32
considerable comfort when walking, which allows the use
of the aeration system of the invention also for sports
and technical shoes.
In particular, the aeration system of the invention
may be used both in normal shoes and in tennis and/or
athletics shoes, in hiking and walking shoes in general
or in work shoes and anti-industrial accident shoes.
It is understood that only some particular
embodiments of the aeration system for shoes object of
the present invention have been described, to which the
man skilled in the art shall be able to bring any
modifications required to adapt it to particular
applications, without however departing from the scope of
protection of the present invention.
It shall, for example, be possible to provide that
the footbed 20 be removable, so as to allow access to the
bellows pump 9 or to the pad 18 to replace them or
impregnate them with more perfume.
