SOLE STRUCTURE AND FOOTWEAR COMPRISING SAID SOLE STRUCTURE

DESCRIPTION

Object of the present invention is a sole structure of a shoe.

A shoe with such a sole structure is further object of the invention.

The leather sole, which was highly widespread in the past, is still used in shoes both in virtue of its aesthetic appearance, which helps to lend a pleasant visual impact to the latter, and in virtue of its natural breathability.

Currently, techniques for increasing the comfort of the leather sole are al so known, for example by improving its ventilation by means of a combination of openings and channels, as described for example in the patent document US3256621 of the company T. SISMAN SHOE COMPANY LTD.

The patent document US3256621 contains the teachings for the imple mentation of a sole comprising a leather tread above which a midsole provided with transversal channels on its coupling surface with the tread and with through openings throughout its thickness, is placed.

Such through openings are in communication with the channels on the bottom and with the inside of the shoe on top.

This way, an exchange of air is favored between the inside of the shoe and the outside environment.

However, such known art has some drawbacks.

First of all, a similar sole structure allows water or other liquids, possibly present on the ground, to penetrate the inside of the shoe through the set of channels and openings.

Moreover, the leather has a natural propensity to absorb water.

Such water, whenever absorbed by a leather sole, enters the shoe through the insole, thus getting the foot of the user wet.

Moreover, the water-soaked leather sole causes an unpleasant cold feel ing and favors the proliferation of molds and bacteria that can lead to its rapid deterioration and/or the formation of unpleasant smells. Techniques aimed at reducing the risk that the water absorbed by the leather sole enters the inside of the shoe, for example through the application of a waterproof and breathable membrane and a sealant on the surface of the sole opposite the ground, such as the one described in the patent document EP1347691 B1 in the name of the same applicant, are also known.

However, such known arts have some aspects which can be improved.

In fact, in such known arts, the transpiration of the shoe through the sole is substantially limited to the overall breathability determined by the leather and the membrane.

Moreover, the breathable area is substantially limited to the zone in which the waterproof and breathable membrane is present, since the sealant, where applied, limits and even prevents the breathability.

Finally, the membrane is considerably affected by the difference in hu midity between the outside environment and the environment inside the shoe: when the leather has absorbed humidity from the outside of the shoe, it takes a certain amount of time to dry and, during this time span, the breathability through the membrane is considerably limited or, even, nonexistent.

Still, the leather soles of known type have a limited shock-absorbing abil ity, i.e. of absorbing the force of an impact and/or shock.

In fact, leather is generally a harder, less flexible and less elastic material than polymeric materials and can thus confer a feeling of stiffness to the foot of a user, thus determining a discomfort that can lead the latter to tire quickly.

Task of the present invention is to provide a sole structure and a shoe that are able to improve the known art in one or more of the aspects set forth above.

Within the context of such task, an object of the invention is to provide a waterproof and breathable sole structure that is able to maintain an adequate breathability also whenever the tread has absorbed water.

A further object of the invention is to develop a waterproof and breathable sole structure that is able to absorb the force of an impact and/or shock with the ground, thus ensuring comfort to the user.

A further object of the invention is to further implement a waterproof and breathable sole structure that can also be used in classic and/or formal types of shoes.

A further object of the invention is to implement a shoe provided with a sole that is able to achieve the objects listed above.

Moreover, the present invention aims to overcome the drawbacks of the know art in an alternative manner to possible existing solutions.

Not least, object of the invention is to implement a sole structure and a shoe with a similar sole structure that are highly reliable, relatively easy to make and at competitive costs.

This task, as well as these and further objects that will become clearer hereunder, are achieved by a sole structure comprising a tread, which compris es at least one portion of breathable material, and a midsole coupled to said tread, said midsole having:

- at least one first channel having at least one ventilation port for the fluid ic communication with the outside environment,

- at least one first through opening in fluidic communication with said at least one first channel, said sole structure being characterized in that it comprises a waterproof and breathable functional element which seals said at least one first opening in a waterproof manner.

This task, as well as these and further objects that will become clearer hereunder, are achieved by a shoe characterized in that it comprises a similar sole structure.

Further characteristics and advantages of the invention will become clearer from the description of some preferred, but not exclusive, embodiments of the sole structure according to the invention, which are depicted by way of example and without limitations in the accompanying drawings, in which:

- figure 1 a depicts a partial view of a first embodiment of a sole structure according to the invention;

- figure 1 b depicts a sectional view of a portion of the sole structure of figure 1a;

- figure 2a depicts an overall view of the first embodiment of the sole structure according to the invention;

- figure 2b depicts a sectional view of a portion of the sole structure of figure 2a;

- figure 3 depicts an overall view of an application of use of the sole structure of figure 2a;

- figure 4 depicts a sectional view of a portion of a sole structure accord ing to the invention in a second embodiment;

- figure 5 depicts a portion of a sole structure according to the invention in a third embodiment;

- figure 6 depicts an exploded view of a sole structure according to the invention in a fourth embodiment;

- figures 7a to 7c each depict an embodiment variant of a first component of the sole structure of figure 6;

- figure 8 depicts a further embodiment variant of a first component of the sole structure of figure 6;

- figure 9 depicts a further embodiment variant of a first component of the sole structure according to the invention in a fifth embodiment;

- figure 10 depicts a partial sectional view of a portion of the sole struc ture according to the invention, according to the sectional plane X-X of figure 9;

- figure 11 depicts a partial sectional view of a sole structure according to the invention in a sixth embodiment, in an application of use thereof;

- figures 12 and 13 are two different views of an application of use of the sole structure according to the invention, in its sixth embodiment;

- figure 14 is a seventh embodiment of a sole structure according to the invention, in an application of use thereof.

With reference to the figures mentioned, a sole structure according to the invention, in a first embodiment thereof, is denoted by the number of reference

10

The sole structure 10 comprises a tread 11 and a midsole 12 coupled to such tread 11.

Such tread 11 comprises at least one portion of breathable material 11’ such as, for example, leather.

The midsole 12 is placed above the tread 11, in configuration of use, and is made of a breathable and/or pierced material.

Such midsole 12 is preferably made of polymeric material, more prefera bly of expanded polymeric material, for example polyurethane (PU) or ethylene- vinyl-acetate (EVA).

The midsole 12 has, on its surface in contact with the tread 11, at least one first channel 13 prevalently arranged in a direction orthogonal to the direc tion of extent of the midsole 12, i.e. prevalently oriented from the outside of the foot towards the inside of the foot.

Such at least one first channel 13 has at least one ventilation port 14 for the fluidic communication with the outside environment.

Advantageously, the first channel 13 has ventilation ports 14 at its two ends.

The midsole 12 has at least one first opening 15.

In the first embodiment of the sole structure 10, the first opening 15 is a through opening and crosses the whole thickness of the midsole 12.

Such as least one first opening 15 opens into the at least one first chan nel 13, putting the outside environment in fluidic communication with the envi ronment above the midsole 12, in configuration of use.

In an embodiment variant not depicted in the figures, such at least one first opening 15 opens onto two or more first adjacent channels 13.

A waterproof and breathable functional element 16 of known type, adapted to cover the at least one first opening 15, thus sealing it in a waterproof manner against water, is placed on the surface of the midsole 12 opposite the one in contact with the tread 11.

In the present description, “waterproof against water” and “waterproof are used alternatively and with the same meaning.

A material is understood as waterproof against water in the absence of crossing points whenever subjected to a pressure of at least 1 bar, for at least 30 seconds.

Specifically, the waterproofness is evaluated as the resistance of the specimen to the penetration of pressurized water, according to the EN1734- 1998 standard.

A sample of material is fixed to close a container provided with a pressur ized water inlet.

The container is filled with water such as to subject the face of the sam ple of material, oriented inside the container, to a hydrostatic pressure of 1 bar.

This condition is maintained for 30 seconds.

The sample is locked between the opening port of the container and a restraining ring, and these are covered with sealing gaskets made of silicone rubber.

The pressurization is obtained by forcing the water coming from a tank into the container, by means of a flow of compressed air.

The compressed air is adjusted by a valve with a pressure gauge on which the pressure reached is shown.

The face of the sample outside the container is thus observed.

The absence of crossing points, consisting in the formation of drops of a diameter between 1 mm and 1.5 mm on such surface, confirms the waterproof ness of the sample.

Whenever there is a need to prevent the deformation of the sample, a grid is fixed thereon, with square meshing, no greater than 30 mm on the side, made of a synthetic material and with threads of a diameter between 1 mm and 1.2 mm.

For example, the functional element 16 is made of expanded polytetra- fluoroethylene (ePTFE) and/or PU and is optionally coupled to one or more lay ers of fabric, knit and/or non-woven fabric which give(s) it support and/or protec tion and/or better workability and/or ease of gluing.

The functional element 16 is joined on the perimeter to the midsole 12, for example by means of glue, according to the already known techniques, such as to form a waterproof seal against water.

Appropriate glues are, for example, hydrophilic polyurethane prepoly mers which are in the semi-liquid state, i.e. in organic solvent solutions, for a dry content of approximately 50% by weight.

The product known under the trade name UCECOAT TD 9627/E of the Belgian company UCB S.A. can, for example, be used.

This way, the possible water present on the ground can reach the first channel 13 and the first opening 15 but without being able to cross them, unlike sweat in vapor state which can pass to the outside environment, as described hereunder.

Some possible outlet paths of the sweat in the vapor state towards the outside environment, through the at least one first opening 15 and the at least one first channel 13, are represented with arrows S in figures 1b and 2b.

The sole structure 10 in an application of use thereof is depicted in figure 3.

In the example depicted in such figure, the sole structure 10 is joined to a shoe upper assembly 17 comprising a shoe upper 18 and an insole 19, thus making a shoe 20.

In particular, the sole structure 10 is joined to the insole 19.

Such insole 19 is breathable and/or pierced. In the example shown in fig ure 3, the insole 19 has a plurality of holes 21.

This way, the passage of sweat in the vapor state from the inside of the shoe 20 towards the outside environment is allowed by passing, in order, through the plurality of holes 21 of the insole 19, the functional element 16, the first opening 15 of the midsole 12, the first channel 13 and the ventilation ports 14.

Such embodiment of the sole structure 10 is advantageous as far as breathability is concerned because, when the leather tread 11 is soaked with water, the humidity absorbed from the outside in the material of the tread 11 re duces the operation, by osmosis, of the functional element 16 due to the gener ation of a humid environment, also on the opposite side of the foot of a user.

However, ventilation that removes the humidity from under the functional element 16, in configuration of use, is allowed by distancing the functional ele ment 16 from the tread 11 by inserting the midsole 12 provided with at least one first channel 13, thus improving its operation.

Moreover, such embodiment of the sole structure 10 is advantageous because the midsole 12 can be made of materials, such as for example PU and/or EVA, particularly adapted to adequately cushion the shocks and/or im pacts with the ground, by choosing their density and hardness depending on the specific needs.

In particular, whenever a carding is provided among the machining for the sole structure 10 on its side surface, the use of EVA is preferable compared to PU, since the removal of the outer film of the EVA, due to the carding, alters its resistance to deterioration in a negligible manner.

In the embodiment shown in figure 3, the at least one first opening 15, the holes 21 and the at least one first channel 13 are arranged only in the fore foot region of the shoe 20.

However, in other embodiments not depicted in the figures, it is possible to place them also in the midfoot and/or in the hindfoot according to contingent needs.

Moreover, in the embodiments depicted in the figures, the midsole 12 has an extent substantially corresponding to that of the tread 11, however, in other embodiments not represented in the figures, the midsole 12 has reduced extent and does not cover:

- the front end of the tread 11 , i.e. the one at the tip of the foot of the user, 9

- and/or the back end of the tread 11 , i.e. the one at the heel of the foot of the user.

In such cases, these ends can, for example, be made of different materi als and/or colors.

The midsole 12 can be provided in a single layer of material or can com prise more layers, for example of different color and/or hardness and/or density.

In the present description, the term “hardness” means the hardness de termined according to the ASTM D 2240-04 standard, whereas the term “densi ty” means the density determined according to the ASTM D 792-00 standard.

In a second embodiment, sectionally depicted in figure 4, the sole struc ture 110 comprises, similarly to the first embodiment, a tread 111 which com prises at least one portion made of breathable material 111’ and a midsole 112 coupled to such tread 111.

The midsole 112 has, on its surface in contact with the tread 111, at least one first channel 113 prevalently arranged in a direction orthogonal to the direc tion of extent of the midsole 112, i.e. prevalently oriented from the outside of the foot towards the inside of the foot.

Similarly to the midsole of the first embodiment, such midsole 112 has at least one first opening 115.

The sole structure 110 comprises a welt 122 placed above the midsole 112, in configuration of use, and is combined therewith by means of known techniques, for example by gluing or co-molding.

The welt 122 is made of a natural, for example leather, and/or synthetic, for example thermoplastic rubber (TR) or EVA, material and/or of a material comprising reground leather combined with binders.

In a third embodiment, partially depicted in figure 5, the midsole 212 comprises:

- a first portion 212’, which is lower in configuration for use,

- a second portion 212”, which is upper in configuration for use and is joined, for example by means of gluing, to the first portion 212’. 10

Such first portion 212’ and the second portion 212” can be made of the same material, for example a polymeric material such as EVA or PU, with hard ness selected according to contingent needs, for example a value of between 20 and 80 Asker C.

For example, it is possible to use a midsole 212 in which the hardness of the second portion 212 is less than the hardness of the first portion 212 such as to offer greater comfort near the foot of the user.

Moreover, it is possible to use a first portion 212’ and/or a second portion 212” of a different hardness inside the portion itself.

For example, it is possible to make:

- the forefoot zone less hard such as to ensure greater comfort to the foot of the user,

- the hindfoot zone harder such as to ensure greater stability to the foot of the user.

The first portion 212’ has at least one first channel 213.

The second portion 212” has at least one first opening 215 in fluidic communication with the at least one first channel 213.

A waterproof and breathable functional element 216 is placed on the sur face of the second portion 212 opposite the one in contact with the first portion 212’, to cover the at least one first opening 215, thus sealing it in a waterproof manner against water.

As in the first embodiment, the functional element 216 is joined to the second upper portion 212”, for example by means of glue according to known techniques, such as to form a waterproof perimetral seal against water.

Such embodiment is advantageous because, since it doesn’t have through openings that put the upper surface of the tread 11 in communication with the functional element 216, it keeps the humidity absorbed by the tread at least partly made of breathable material 11’, advantageously leather, away from the latter, thus consequently improving its performance.

Some possible outlet paths of sweat in the vapor state are denoted by ar- 11 rows S in figure 5.

In a fourth embodiment, partially represented exploded in figure 6, the midsole 312 comprises:

- a first portion 312’, which is lower in configuration for use, having at least one first channel 313,

- a second portion 312”, which is upper in configuration for use and is joined, for example by means of gluing, to the first portion 312’, having at least one first opening 315.

In such embodiment, the waterproof and breathable functional element 316 is combined with the surface of the second portion 312” of the midsole 312 facing the first portion 312’.

In practice, the functional element 316 is interposed between the second portion 312” and the first portion 312’.

Also in this case, the functional element 316 is combined with the second portion 312” by means of glue, thus closing the at least one first opening 315 and forming a waterproof seal against water.

Such embodiment is particularly advantageous because it protects the functional element 316, for example from rubbing or contact:

- with possible roughnesses present on the insole 19,

- with the tools used by the operator when joining the sole structure to the shoe upper assembly 17.

A first variant of the first portion of figure 6, generally denoted by the number of reference 412’, is represented in figure 7a.

The first portion 412’ comprises one or more second openings 423 in flu idic communication with the at least one first channel 413.

Such embodiment is advantageous, for example in particularly dry cli mates, because it allows transpiration also through the tread 111, at least in its portion of breathable material 111’ .

A second embodiment variant of the first portion of figure 6, generally de noted by the number of reference 512’, is represented in figure 7b. 12

Such first portion 512’ has one or more first channels 513 delimited by first ribs 524.

One or more of the first channels 513 can be interrupted by second ribs 525 connecting two successive first ribs 524, thus providing blind channels

513a, 513b

Such embodiment is particularly advantageous because it allows to strengthen the first portion 512’ of the midsole.

A third embodiment variant of the first portion of figure 6, generally de noted by the number of reference 612’, is represented in figure 7c.

Such first portion 612’ has one or more second channels 626 for the connection between the first channels 613.

A similar embodiment is particularly advantageous because it increases the paths useful for ventilation and the coming out of sweat in the vapor state from the shoe.

A fourth embodiment variant of the first portion of figure 6, generally de noted by the number of reference 712’, is represented in figure 8.

Such first portion 712’ has a substantially median cavity 727 in which one or more first channels 713 merge.

A similar embodiment is particularly advantageous because the cavity 727 constitutes a means for pumping the air under the thrust of the weight of a user, at each step, thus considerably increasing the flow of air crossing the first channels 713.

A fifth embodiment variant of the first portion of figure 6, generally denot ed by the number of reference 812’, is represented in figures 9 and 10.

Such first portion 812’ is made of a three-dimensional fabric.

In the present description, the expression “three-dimensional fabric” means a single fabric whose constituent fibers are arranged in a mutually per pendicular planar relationship. In particular, in the weaving of a three- dimensional fabric, the set of fibers x and y are woven with the rows and col umns of the axial fibers z, wherein the set of fibers x and y are respectively the 13 set of horizontal and vertical weaves, whereas the fibers z constitute the set of multilayer warp.

It is also possible to form three-dimensional fabrics with weaving pro cesses of two-dimensional type.

Moreover, the three-dimensional fabric can also be formed by knitting on straight or circular knitting machines.

Specifically, the three-dimensional fabric with which the first portion 812’ is made is, for example, the one known under the trade name “Air Spring” formed by a first layer 828 and a second layer 829 of polyester fabric, which are woven such as to form the ribs of at least one first channel 813.

The first layer 828 and the second layer 829 are of spun material, thus of textile nature, and are thus permeable to air, thus making the fluidic communi cation between the at least one first channel 813 and the at least one first open ing of the midsole, not represented in figures 9 and 10, possible.

Preferably, such three-dimensional fabric is made with a monofilament, such as to reduce the possible dragging of water by capillarity.

Such embodiment is advantageous due to the use of a three-dimensional fabric, because it allows to considerably lighten the sole structure while simulta neously increasing its ventilation, since such three-dimensional fabric can be crossed by air in any direction.

In general, the selection of the materials used for making the midsole 12, 112, 212, 312, the first portion 212', 312', 412', 512', 612', 712', 812', and the second portion 212", 312", can be made not only according to the hardness but also according to the elastic rebound of the material and/or the ratio between the elastic and viscous components thereof.

In the present description, the expression “elastic rebound of a material” means what is also named “rebound resilience” and is measured as the amount of energy that is restored to a pendulum impacting a specimen of the material in question. In the present description, the expression “ratio between the elastic and viscous components of a material” means what is also named “compres- 14 sion set” and substantially represents the residual deformation, thus the plastic (or permanent) deformation of the material following a given deformation, thus such ratio determines how likely a material is able to return to its original dimen sion after having been subjected to given stress.

Thus, in general, it is preferable to use materials with a high “rebound re silience” value and a low “compression set” value, such as to ensure an ade quate dampening of the shocks to which the foot of a user is subjected and a considerable duration over time of both the shape and dimension of the compo nent in question.

Preferably, the “compression set”, determined according to the method B of the ASTM D 395-03 standard, is of less than approximately 55%, more pref erably of less than approximately 40%, even more preferably of less than ap proximately 20%.

Preferably, the “rebound resilience”, determined according to the method B of the ASTM D 1054-2000 standard, is at least equal to 40%, more preferably at least equal to approximately 50%, even more preferably at least equal to ap proximately 60%.

In general, the tests listed above are applicable to materials for soles and, for the purposes of the present invention, can also be applied to the three- dimensional fabrics to be used in the first portion 812’.

A further embodiment of a sole structure according to the invention, in an application of use thereof generally denoted by the number of reference 910, is partially sectionally depicted in figure 11.

The sole structure 910 comprises a tread 911 with a body made of poly meric material which has at least one portion 911’ made of breathable material, such as, for example, leather, embedded on the surface adapted for contact with the ground in configuration of use.

Such at least one portion 911’ made of breathable material can be made flush with the surface of the tread 911 adapted for contact with the ground, or in low relief with respect to it, such as to be less subject to direct contact with the 15 ground itself which could deteriorate it more quickly.

Such at least one portion 911’ made of breathable material is glued on the polymeric body of the tread 911 and/or co-molded thereto.

The midsole 912 of the type described in one of the embodiments de picted previously, is placed above the at least one portion 911’ made of breath able material.

In the case depicted, the midsole 912 comprises a first portion 912’ and a second upper portion 912” that are similar to the one described in one of the previous embodiments.

Such midsole 912 can be placed in direct contact with the at least one portion 911’ made of breathable material of the tread 911 or, as depicted in fig ure 11 , an air-filled chamber 930 interposed between the midsole 912 and the at least one portion 911’ can be present.

Such air-filled chamber 930 is advantageous because it helps to further cushion the stresses transmitted to the foot of the user.

In general, the use of a tread 911 with a body made of polymeric material having one or more leather portions 911’ allows to obtain a wide variety of soles of more luxurious aspect than the soles fully made of polymeric material, thus ensuring considerable freedom of execution.

Moreover, the polymeric material of the tread 911, interposed between the portions 911’ made of breathable material, allows to increase the flexibility of the sole structure 910 with respect to a similar sole structure fully made of leather.

The embodiment depicted in figure 11 is particularly advantageous be cause the midsole 912 placed above the at least one portion 911’ balances the latter's reduced ability of absorbing the shocks.

A side view and a bottom view of the sole structure 910 in the application of use of figure 11 are depicted respectively in figures 12 and 13.

With reference to figure 12, the first portion 912’ of the midsole extends up to being visible from the outside, thus allowing a great number of aesthetic 16 variants, for example with a color in contrast with that of the tread 911 and/or the welt 922.

The second portion 912” of the midsole 912 is no longer visible in figure 12 because it has an extent smaller than the extent of the first portion 912’ .

This allows to obtain a more uniform appearance and to facilitate the making of the tread 911 of polymeric material.

In a further particularly preferred embodiment variant depicted in figure 14, the midsole 912 is made in one piece with the tread 911.

In such embodiment variant, also the welt 922 is made in one piece with the midsole 912.

The welt 922 can anyhow initially be a separate component to be joined to the midsole 912 by gluing or co-molding, thus allowing greater freedom of execution.

With reference to the embodiment variant depicted in figure 14, the body of the tread 911 and the midsole 912 are made, for example, in a single molding process by pouring or injecting a polymeric material.

The tread 911 comprises at least one portion 911’ made of breathable material, for example leather, embedded on its surface adapted for contact with the ground in configuration of use.

The polymeric material used to make the midsole 912 in one piece with the body of the tread 911 has hardness between 60 and 80 Asker C, or between 50 and 75 Shore A.

Preferably, the density of the polymeric material is less than 1.25 g/cm ³ , more preferably less than 1.1 g/cm ³ , and even more preferably less than 0.95 g/cm ³ .

In some embodiments, the density of the polymeric material is less than 0.90 g/cm ³ , more preferably less than 0.80 g/cm ³ .

The polymeric material used in this embodiment is, in practice, the same for the body of the tread 911 and for the midsole 912 and, thanks to its struc ture, it is able to cushion the shocks in effective manner, thus balancing the 17 lesser ability to cushion the shocks of the at least one portion 911’ made of breathable material.

In general:

- the thickness of the tread 11, 111, 911 is preferably between 3 mm and 10 mm,

- the thickness of the midsole 12, 112, 312, 912 is preferably between 2 mm and 40 mm,

- the thickness of the first portion 212', 312', 412', 512', 612', 712', 812', 912' and of the second portion 212", 312", 912" of the midsole 212, 312, 912 is preferably between 2 mm and 14 mm.

The at least one first opening 15, 115, 215, 315 has:

- a substantially circular or semicircular shape of a diameter between 1 mm and 10 mm,

- and/or a substantially ellipsoidal and/or quadrangular shape of smaller dimension between 1 mm and 10 mm and of greater dimension between 1 mm and 50 mm.

Such at least one first opening 15, 115, 215, 315 preferably has an area between 1 mm ² and 150 mm ² .

Such at least one first channel 13, 113, 213, 413, 513, 613, 713, 813 has span between 1 mm and 5 mm and a depth between 1 mm and 5 mm.

In the present description, the term “span” means the distance between the opposite edges of the first channel.

In practice, it was noted how the invention reaches the intended task and objects by making a waterproof and breathable sole structure that is able to maintain an adequate breathability also when the leather tread has absorbed water.

A waterproof and breathable sole structure that is able to cushion the force of an impact and/or shock with the ground, thus ensuring comfort to the user, was developed with the invention.

A waterproof and breathable sole structure that can also be used in clas- 18 sic and/or formal types of shoes was made with the invention.

Finally, a shoe provided with a sole that is able to achieve the objects listed above was developed with the invention.

The invention, as designed, is susceptible of numerous changes and var- iants, all falling within the inventive concept; moreover, all the details may be replaced by other technically equivalent elements.

In practice, the materials used, as long as compatible with the specific use, and the contingent dimensions and shapes may be any depending on the requirements and state of the art. Whenever the characteristics and techniques mentioned in any claim are followed by reference marks, such marks were only affixed for the single pur pose of increasing the intelligibility of the claims and, consequently, such refer ence marks have no limiting effect on the interpretation of each element denot ed by way of example by such reference marks.