Waterproof and breathable sole structure and respective manufacturing method

Abstract

A waterproof and breathable sole structure is provided with a cost- effective PFAS-free waterproof and breathable membrane. The sole structure can be made with a monolithic sole or a midsole joined to a tread, all of which being provided with a breathable or pierced forefoot portion. An assembly is sealed in a waterproof manner to the sole, or to the midsole or the tread, at the breathable or pierced portion, and comprises at least one waterproof and breathable membrane, and a waterproof reinforcing element of the at least one membrane, the waterproof reinforcing element at least partially overlapping the at least one membrane and sealed thereto in a watertight manner. The reinforcing element extends into the forefoot region most subject to flexing and leaves at least one area of the membrane exposed. Therefore, the at least one membrane is mechanically reinforced and sealed, resistant over time to the flexing stresses imparted by the user, and acquires a long-lasting barrier function against water penetration in the event that the membrane itself breaks.

Description

[0001] WATERPROOF AND BREATHABLE SOLE STRUCTURE AND RESPECTIVE MANUFACTURING METHOD

[0002] ***

[0003] DESCRIPTION

[0004] Field of the Invention

[0005] The present invention relates to the field of footwear, and specifically relates to a waterproof and breathable sole structure and a method for manufacturing it.

[0006] State of the art

[0007] Footwear generally comprises a sole and an upper assembly fixed above the sole. The sole, in turn, may be monolithic, that is, constructed as a single piece, or it may be made by joining a midsole to a tread.

[0008] In order to make footwear comfortable, breathable sole structures have been proposed, and in particular soles equipped with through holes located mainly in the region corresponding to the user's forefoot; the through holes allow vapor phase sweat, produced by the user's foot, to escape through the sole.

[0009] It is known that a waterproof and breathable membrane, hereinafter simply referred to as membrane, is arranged over these through holes with the dual function of preventing water from entering the inside of the footwear from the outside while, at the same time, allowing vapor to escape. In other words, the membrane, also referred to as functional layer, has a barrier effect that prevents water from entering the footwear through the through-holes, and is therefore waterproof but allows vapor produced by the user to escape to the outside, through the same through-holes, and is therefore vapor permeable or breathable.

[0010] Definitions

[0011] The term midsole refers to an element or layer, of any nature, interposed between the sole and the insole, according to the general definition given in Standard EN ISO 19952:2005, item 106, page 18. For the purposes of this description, a component of the sole structure, considered in isolation, is waterproof if water does not pass through it when the material is subjected to a pressure of at least 1 bar, maintained for at least 30 seconds. More specifically, waterproofness is evaluated as the resistance of the specimen to the penetration of pressurized water, according to the method described in Standard EN1734. According to this method, a sample of material is fixed so as to close a container provided with an inlet for water under pressure. The container is filled with water so that a defined pressure is applied to the face of the material sample facing the container. The sample is secured between the opening mouth of the container and a retaining ring, both being covered with silicone rubber seals. Pressurization is achieved by forcing water from a tank into the container by means of a flow of compressed air. The latter is regulated by a valve with a pressure gauge indicating the pressure reached. For the purpose of the present invention, a hydrostatic pressure of 1 bar and an observation time of 30 seconds are defined. The face of the sample outside the container is then observed. The absence of crossing points, consisting in the formation on that surface of droplets between 1 mm and 1.5 mm in diameter, denotes the waterproofness of the sample. If necessary, to prevent the deformation of the sample, a square mesh grid of synthetic material with a side not exceeding 30 mm and made of threads 1 mm to 1 ,2 mm in diameter, may be fixed to the sample.

[0012] The assembled sole structure is waterproof if it is not affected by water penetration when subjected to the tests specified in Standard EN1734, considering an observation time of 5 seconds and a pressure of 1 bar:

[0013] - at three different points, typically toward the toes, at rearward position toward the medial foot and at rearward position toward the lateral foot, for a sole structure of a size greater than or equal to French size 35, and

[0014] - at only two points for sizes smaller than French size 35.

[0015] Vapor permeability is the amount of vapor that passes through a material due to a partial pressure gradient. Specifically, Standard ISO 20344-2004, in chapter 6.6 “Determination of water vapor permeability” relating to safety footwear, describes a testing method consisting of fixing a specimen of the material to be tested so as to close the opening of a bottle containing a certain quantity of solid desiccant, that is to say silica gel. The bottle is subjected to a strong current of air under conditioned atmosphere. The bottle is rotated so as to mix the solid desiccant and optimize its action of drying the air contained in the bottle. The bottle is weighed before and after the test period to determine the moisture mass that has passed through the material and has been absorbed by the solid desiccant. The water vapor permeability, expressed in milligrams per square centimeter per hour [mg / cm2h], is then calculated on the basis of the measured mass of moisture, the area of the bottle opening and the test time.

[0016] To be thorough, the definition of water resistance is also provided. A material is called water-resistant when a droplet of water can slide on its surface because a very high contact angle is generated between surface and droplet, and this prevents the absorption by the material itself in the absence of hydrostatic pressure. The contact angle between water droplet and surface, and the surface tension of the surface, are commonly used to measure the water resistance of a surface.

[0017] Standard 20344-2004, in Chapter 5.17.3 "Preparation of test pieces" identifies the portion of the assembled sole that is to be subjected to permeability tests by referring to the anatomy of the human foot.

[0018] Usually the membrane is ovoid, circular or elliptical in shape, and its extent is such that it does not overhang the sole but, on the contrary, remains within the edge of the sole to allow sealing, as will now be explained. More specifically, the longitudinal extent of the membrane, i.e. the extent in the direction of the main dimension of the sole, is usually between 20% and 80% of the total length of the sole; the extent in the transverse direction is usually less than 90% of the sole extent. In some of the known solutions, the membrane is inserted into a corresponding seat, basically a cavity or bas-relief, formed on the top surface of the sole, that is, the surface facing the sole of the user's foot, so that a step remains between the seat and the edge of the sole. The membrane is inserted into the seat and sealed to the sole by means of a gasket, called seal ring, which extends around the perimeter of the sole, overlapping the edge of the membrane.

[0019] In practice, the seal ring is glued to both the sole and the membrane, so that it straddles the edge of the membrane and an annular portion of the sole.

[0020] Solutions of this type are described, for example, in WO 2017 / 042127, which describes a seal ring denoted by the reference 23 in Figure 4, and in WO 2016 / 202658, which describes a seal ring denoted by the reference 29 in Figure 1 , both in the name of the Applicant.

[0021] Other known solutions are described in CN 205512649LI, CN 202145955U, CN 201451618U and CN 205180507U.

[0022] A limitation of soles equipped with a waterproof and breathable membrane in the forefoot is the relatively poor durability of the membrane, resulting from the poor flexing resistance of the material(s) used to make it. During walking, the front portion of the sole, which hereinafter will be referred to as the forefoot by analogy with the anatomy of the user's foot, is repeatedly bent, thus subjecting the membrane to continuous mechanical stresses. These stresses can cause the membrane to break, resulting in loss of sole waterproofing.

[0023] For this reason, footwear manufacturers have chosen to reinforce the membrane with materials characterized by better flexing resistance: therefore, over time the market has turned to membrane laminates, which basically consist of membranes laminated, i.e., coupled, to supporting layers such as fabrics, felts, nets, knits or fibers of composite materials, as described in EP 1332046 B1 in the name of the Applicant.

[0024] An example of membrane laminate is known under the trade name Gore-

[0025] Tex®.

[0026] Generally, the membrane laminates comprise membranes of expanded polytetrafluoroethylene (ePTFE) that achieve relatively high values of water vapor permeability and mechanical strength. However, per- and polyfluoroalkyl substances (PFASs), which are carcinogenic according to recent studies, are used in the production of ePTFE membranes; PFASs have already been banned in California and New York State. It is likely that ePTFE membranes will be banned also in other jurisdictions in a relatively short time.

[0027] However, at present, there are no commercially available membranes that have sufficient mechanical flexing resistance and are PFAS-free, i.e. that do not involve PFAS in the production cycle. In other words, PFAS-free membranes available today are not suitable for use as membranes in breathable soles because of poor durability due to low resistance to repeated flexing stresses.

[0028] Therefore, there is a need to find a solution that allows PFAS-free membranes to be used even under conditions of severe flexing stresses, such as those occurring in a footwear sole.

[0029] Summary of the invention

[0030] Therefore, a first technical problem underlying the present invention is to provide a waterproof and breathable sole structure provided with a PFAS-free waterproof and breathable membrane that would overcome the limitations of known solutions.

[0031] In the context of this task, an object of the present invention is to make a sole structure with high degree of reliability and resistance to stresses, particularly flexing stresses.

[0032] A further object of the present invention is to make a sole structure equipped with a PFAS-free waterproof and breathable membrane at low cost. In particular, the aim is to construct the sole structure in such a way that it remains waterproof even if the membrane breaks.

[0033] A further object is to provide a process for making a waterproof and breathable sole structure equipped with a PFAS-free waterproof and breathable membrane, which is simple to implement, economical and reliable. Therefore, the present invention relates to a sole structure according to claim 1 , comprising:

[0034] (i) a sole provided with a breathable or pierced forefoot portion, in which the sole extends lengthwise along a longitudinal axis b extending in the forefoothindfoot direction;

[0035] (ii) an assembly comprising

[0036] - at least one waterproof and breathable membrane extending at least partially at the breathable or pierced forefoot portion of the sole, and

[0037] - a waterproof reinforcing element, at least partially overlapping the at least one membrane, in a watertight manner.

[0038] The assembly formed by the at least one membrane and the reinforcing element is sealed to the sole in a waterproof manner.

[0039] Advantageously, at least one portion of the reinforcing element extends transversely to the longitudinal axis of the sole, at the breathable or pierced forefoot portion subject to maximum flexing, and leaves at least one area of the at least one membrane exposed.

[0040] The portion of the forefoot subject to maximum flexing corresponds to a portion of the sole structure that extends near, or straddles, the flexing line defined in Standard ISO 20344:2004(E), paragraph 8.4, page 64; in practice, the flexing line is orthogonal to the longitudinal axis b and intersects it at one- third of the length of the longitudinal axis b, starting from the toe of the sole. In more detail, Standard ISO 20344:2004(E) denotes the flexing line of the sole structure as AC: the line AC intersects the longitudinal axis XY of the sole structure at 90°, at a point located at one third of the length L of the axis XY, i.e. , at the point corresponding to distance of L / 3 from the toe of the sole structure.

[0041] For simplicity, the longitudinal axis can be identified with the Brannock axis. Standard ISO 20344:2004(E) describes in paragraph 5.3.2 (page 10) how to identify the longitudinal axis.

[0042] Therefore, the portion of maximum flexing is approximately at, or straddles, the flexing line at about 1 / 3 of the overall length of the sole structure, starting from the toe.

[0043] In practice, the flexing line AC line identified by the above-mentioned standard corresponds to the line of maximum flexing, considering that the maximum flexing of the sole occurs right at the forefoot during walking.

[0044] The overlap of the reinforcing element on the membrane is to be understood as relative, meaning that the reinforcing element can be positioned above or below the membrane, as long as these two components overlap each other, possibly even with the interposition of other components.

[0045] The choice of using a reinforcing element that extends transversely over the breathable or pierced portion of the forefoot, at the portion of the sole structure subject to greatest flexing during walking, provides the following advantages.

[0046] The functional layer, herein simply referred to as the membrane, is mechanically reinforced, as the reinforcing element is used to resist over time the flexing stresses exerted by the user during the use of the footwear.

[0047] Another advantage is that the reinforcing element ensures the barrier effect against water in the event of membrane break. Since the reinforcing element is joined to the membrane in a watertight manner and the resulting assembly is sealed to the sole in a waterproof manner, any infiltration of water through the membrane, which is no longer undamaged in the region of greatest wear, would not result in water entering the footwear, because the water would be stopped exactly by the reinforcing element. In this regard, membrane reinforcements such as fabrics, felts, nets, knits or fibers of composite materials are known (see, for example, EP 1332046 B1 in the name of the Applicant), but none of these are both waterproof and joined in a watertight manner to the membrane at the portion of greatest flexing.

[0048] However, the overall breathability of the footwear provided with the sole structure according to the present invention remains acceptable even if the reinforcing element is not breathable. It should be said that, as will be explained in detail below, the area of the sole affected by the reinforcing element is still useful for the escape of vapor phase sweat from the through-holes of the sole structure.

[0049] Clearly, if the membrane, or membranes is / are overlapped by the reinforcing element across (substantially) the entire width of the breathable or pierced forefoot portion, what was traditionally a single breathable area is now partitioned into a front area positioned right forward of the reinforcing element and the portion of maximum flexing, and a rear area positioned right rearward of the reinforcing element and the portion of maximum flexing.

[0050] The reinforcing element overlapping the membrane, or membranes, resists flexing stresses longer than the membrane and therefore makes the sole structure more durable compared to the sole structure without the reinforcing element, all other factors being equal.

[0051] Preferably the reinforcing element extends across the entire width of the at least one membrane.

[0052] Preferably, the reinforcing element extends across the entire useful width of the sole, between the left intrados and right intrados of the sole.

[0053] Preferably, the reinforcing element is not breathable and / or has no holes.

[0054] Preferably, the reinforcing element is glued or joined to the at least one membrane in a watertight manner at the full extent of the reinforcing element, i.e. , these two components are coupled along the entire extent of the reinforcing element.

[0055] Preferably, at least one first area and at least one second area of the at least one membrane are left exposed (i.e. not covered) by the reinforcing element. The reinforcing element extends rearward of the first area and / or forward of the second area, with respect to the longitudinal axis b. The longitudinal extent of the reinforcing element must be sufficient so that the portion of the breathable or pierced forefoot subject to maximum flexing, as defined above, is kept within the area of the reinforcing element itself. In other words, the reinforcing element must extend at least in the portion subject to maximum flexing. Optionally, the reinforcing element is joined to the at least one membrane in a watertight manner, not only at the portion subject to maximum flexing but also at the perimeter of the breathable or pierced forefoot portion, and also optionally at the perimeter of the first area and / or second area. In other words, the reinforcing element can be shaped like a tape but it can also have a more complex shape, so as to enclose the areas of the membrane that have been left exposed.

[0056] The sole structure according to the present invention can be made alternatively:

[0057] - with the monolithic sole, i.e., defined by a single component, the reinforcing element being an element distinct from the sole and the at least one membrane, or

[0058] - with the sole obtained by combining a midsole with the respective tread. In this circumstance, both the midsole and the tread are provided with a breathable or pierced forefoot portion and the reinforcing element is either a waterproof portion of the midsole or a distinct element of the midsole, which at least partially overlaps the at least one membrane and is joined thereto in a watertight manner.

[0059] Therefore, the following definitions can be given:

[0060] - the assembly formed by the at least one membrane and the reinforcing element distinct from the sole is defined as first assembly, and

[0061] - the assembly formed by the at least one membrane and the reinforcing element integral with the midsole is defined as second assembly.

[0062] Having introduced the previous definitions, the sole structure can be made according to one of the following embodiments in which the first assembly is incorporated:

[0063] - a seat is formed on the top surface of the sole and the first assembly is housed entirely inside the seat, or the at least one membrane is housed in the seat and the reinforcing element extends at least partially around the at least one membrane outside the seat, or - the first assembly is joined to the top surface of the sole, without a specific seat for the first assembly being formed thereon, or

[0064] - a seat, inside which the first assembly is housed, is formed on the bottom surface of the midsole and the midsole, with the first assembly, is joined to a tread; or

[0065] - the first pre-assembled assembly is loaded onto a mold to make the sole by injection, that is, the sole is formed by injection on the first assembly, or

[0066] - a seat, inside which the at least one membrane is housed, is formed on the top surface of the sole and the sole is joined to, or injected on, an upper assembly provided at the bottom with the reinforcing element joined to the at least one membrane in a watertight manner. Thus, in this embodiment, the first assembly is defined by the at least one membrane and the reinforcing element previously arranged on the upper assembly, or

[0067] - a seat, inside which the first assembly is housed, is formed on the top surface of the tread and the tread, with the first assembly, is joined to a midsole.

[0068] As an alternative, the sole structure can be made according to the following embodiments in which the second assembly is incorporated:

[0069] - a seat in which the reinforcing element, an integral part of the midsole, extends and in which the at least one membrane is housed, is formed on the bottom surface of the midsole. The at least one membrane and the reinforcing element define together the second assembly, and the midsole with the second assembly is joined to a tread; or

[0070] - a seat, inside which the at least one membrane is housed, is formed on the top surface of the tread, and the reinforcing element, as integral part of the midsole, is defined on the bottom surface of the midsole, so that the at least one membrane and the reinforcing element together define the second assembly when the tread is joined to the midsole.

[0071] Clearly, the sole structure incorporating the first assembly or the second assembly is joined to or formed on an upper assembly to complete the footwear.

[0072] Preferably each membrane is made of a PFAS-free polymeric material, or is a laminate made of multiple PFAS-free materials.

[0073] For example, the at least one membrane is a sheet made of a material selected from polyurethane, polyethylene, polypropylene, polyester and combinations thereof, or is a laminate made of several sheets of one or more of these materials.

[0074] Preferably, the at least one membrane extends over the entire breathable or pierced portion of the forefoot to maximize the breathability of the footwear.

[0075] Preferably, the longitudinal extent of the assembly, that is, both the first assembly and the second assembly, is between 20% and 80% of the total length of the sole.

[0076] Preferably, the construction lines that will now be defined are used for making the assembly. Considering the footprint of the sole on the ground and considering the anatomy of the human foot, three construction lines r, s, t are defined on the plane of the footprint:

[0077] - construction line r which passes through point B, which point B represents the end of the first metatarsal facing the proximal phalanx of the big toe, and which intersects the outer contour of the at least one membrane at a point Y by passing forward of the distal phalanx of the fifth toe, preferably tangential to the upper end thereof;

[0078] - construction line s which bisects the proximal phalanx of the big toe, forward of point B and at a distance from point B equal to about 15-20 mm, measured in parallel to the Brannock axis, and which intersects the outer contour of the at least one membrane at a point X substantially within the distal phalanx of the fourth toe;

[0079] - construction line t which extends from the intersection point O between the construction line r and the construction line s and which intersects the outer contour of the at least one membrane at a point Z, and wherein the length of the contour of the at least one membrane between the points Y and Z is equal to half the length LXY of the contour of the at least one membrane between the points X and Y, i.e. LXY = 2»LYZ, wherein the reinforcing element extends between the s and t construction lines.

[0080] Preferably, the at least one membrane defines at least one area permeable to water vapor between the construction line s and the front contour of the at least one membrane. The same membrane or a second membrane defines another area permeable to water vapor between the construction line t and the rear contour of the at least one membrane.

[0081] The construction line r corresponds in practice to the flexing line AC defined in Standard ISO 20344:2004(E), paragraph 8.4, page 64. The breathable or pierced forefoot portion subject to maximum flexing corresponds to a portion of the sole structure that extends at, or straddles, the flexing line just mentioned.

[0082] The breathable or pierced forefoot portion subject to maximum flexing can also be identified by resorting to the following definition. Considering that the total length of the sole along said longitudinal axis is equal to L, the breathable or pierced forefoot portion subject to maximum flexing corresponds to a portion of the sole structure which extends at, or straddles, the flexing line r which intersects orthogonally the longitudinal axis b at the point which is at a distance equal to L / 3 from the toe of the sole. The flexing line r coincides with the construction line r described above.

[0083] According to another definition, considering the footprint of the sole on the ground and assuming equal to L the total length of the sole along the longitudinal axis b, the three construction lines r, s, t in the plane of the footprint are defined as follows:

[0084] - construction line r, which intersects orthogonally the longitudinal axis b at the point that is at a distance equal to L / 3 from the toe of the sole and intersects, at a point Y, the outer contour of the at least one membrane;

[0085] - construction line s, which intersects the longitudinal axis b at a point that in men's size 42 is 15-20 mm forward of the construction line r, and intersects, at a point X forward of the point Y, the outer contour of the at least one membrane;

[0086] - construction line t, which intersects the longitudinal axis b at a point that in men's size 42 is 12-15 mm rearward of the construction line r, and intersects, at a point Z rearward of the point Y, the outer contour of the at least one membrane, wherein the length (LYZ) of the contour of the at least one membrane between the points Y and Z is equal to half the length (LXY) of the contour of the at least one membrane between the points X and Y, i.e.

[0087] LXY = 2»LYZ, wherein the reinforcing element extends between the s and t construction lines.

[0088] The construction lines s and t can be parallel, or nearly parallel, or intersect at a point 0 outside the sole structure.

[0089] A second aspect of the present invention relates to a method for manufacturing a footwear sole structure, according to claim 22.

[0090] The method comprises providing:

[0091] (i) a sole having a breathable or pierced forefoot portion and a dimension running along a longitudinal axis b in forefoot-hindfoot direction, for example the Brannock axis,

[0092] (ii) an assembly comprising at least one waterproof and breathable membrane and a reinforcing element made of waterproof material, the method comprising:

[0093] - positioning the at least one membrane at least partially at the breathable or pierced forefoot portion,

[0094] - overlapping at least one part of the reinforcing element on the at least one membrane and joining it to the latter in a watertight manner,

[0095] - sealing the assembly to the sole in a waterproof way.

[0096] Advantageously, the method provides that at least one portion of the reinforcing element is arranged transversely to the longitudinal axis b at the breathable or pierced forefoot portion subject to maximum flexing. In addition, the method provides that the reinforcing element is positioned so that at least one area of the at least one membrane is left exposed.

[0097] The advantages are as described above in relation to the sole structure.

[0098] Preferably, the reinforcing element is positioned, with respect to the at least one membrane, in such a way as to leave exposed:

[0099] - at least one first area being forward of the reinforcing element, at the at least one membrane, and

[0100] - at least one second area being rearward of the reinforcing element, at the same membrane or at least one second membrane.

[0101] Brief description of the figures

[0102] Further characteristics and advantages of the invention will be more evident from the review of the following specification of some preferred, but not exclusive, embodiments depicted for illustration purposes only and without limitation, with the aid of the attached drawings, wherein:

[0103] - Figure 1 is a perspective and exploded view of a sole structure according to the known art;

[0104] - Figure 2 is a perspective and exploded view of a sole structure according to the present invention;

[0105] - Figure 3a is a schematic plan and top view of the sole structure according to the present invention and of corresponding construction lines r, s, t;

[0106] - Figure 3b is a schematic plan and top view of the first assembly, comprising a single membrane;

[0107] - Figure 3c is a schematic plan and top view of an alternative version of the first assembly;

[0108] - Figure 3d is a schematic plan and top view of an alternative version of the first assembly;

[0109] - Figure 3e is a cross sectional view of the sole structure portion, considered on the plane A' -A' of figure 3b;

[0110] - Figure 3f is a cross sectional view of the portion of sole structure, considered in the plane A-A of figure 3b;

[0111] - Figure 3g is a schematic plan and top view of an alternative version of the first assembly;

[0112] - figure 3h is an exploded and cross-sectional view of a sole structure equipped with the first assembly of figure 3g, considered in the C-C section plane;

[0113] - Figure 3i is a cross sectional view of the first assembly, considered in the plane C’-C’ of figure 3g;

[0114] - Figure 3m is a schematic plan and top view of an alternative version of the first assembly, comprising two membranes;

[0115] - Figure 4 is an enlargement of a portion of figure 3a;

[0116] - Figure 5 is a schematic and perspective rear view of a left shoe comprising a sole structure according to the present invention;

[0117] - Figure 6 is a cross sectional view of the shoe shown in figure 5, considered in the vertical section plane B-B shown in figure 5;

[0118] - Figure 7 is a top perspective and exploded view of the shoe shown in figure 5;

[0119] - Figure 8 is a schematic and perspective rear view of a left shoe comprising a different sole structure according to the present invention;

[0120] - Figure 9 is a cross sectional view of the shoe shown in figure 8, considered in the vertical section plane B-B shown in figure 8;

[0121] - Figure 10 is a perspective and exploded bottom view of the shoe shown in figure 8;

[0122] - Figure 11 is a schematic and perspective rear view of a left shoe comprising a different sole structure according to the present invention;

[0123] - Figure 12 is a cross sectional view of the shoe shown in figure 11 , considered in the vertical section plane B-B shown in figure 11 ;

[0124] - Figure 13 is a perspective and exploded bottom view of the shoe shown in figure 11 ;

[0125] - Figure 14 is a schematic and perspective rear view of a left shoe comprising a further sole structure according to the present invention;

[0126] - Figure 15 is a cross sectional view of the shoe shown in figure 14, considered in the vertical section plane B-B shown in figure 14;

[0127] - Figure 16 is a top perspective and exploded view of the shoe shown in figure 14;

[0128] - Figure 17 is a schematic and perspective rear view of a left shoe comprising a further sole structure according to the present invention;

[0129] - Figure 18 is a cross sectional view of the shoe shown in figure 17, considered in the vertical section plane X-X shown in figure 17;

[0130] - Figure 19 is a cross sectional view of the shoe shown in figure 17, considered in the vertical section plane Y-Y shown in figure 17;

[0131] - Figure 20 is a plan and bottom view of a component of the shoe shown in figure 17;

[0132] - Figure 21 is a perspective and exploded bottom view of the shoe shown in figure 17.

[0133] Detailed description of the invention

[0134] Figure 1 is a schematic and exploded view of a sole structure 10’ according to the known art described in WO 2016 / 202658. The sole structure 10' comprises a first shaped element 1T made of polymeric material, which has a hollow bottom portion in the arch region delimited by a frame and having a through opening 14' orthogonal to the lying position on the ground. The sole structure 10' comprises a shaped and relatively flat element 19' joined from below to the first element 1T by gluing. The top surface of the shaped element 19' has recesses and protrusions 2T defining passages for air, vapor and liquids. In addition to the two elements 1T and 19', the sole structure 10' comprises a waterproof and breathable membrane 28', basically in form of sheet, sealed to the first element 1T from above at its inner edge which delimits the opening 14', in order to prevent water infiltration. Specifically, the seal of the membrane 28' to the first top element 1T is achieved by using a ring 29' of waterproof material, e.g., PVC, which, from the top of the first element 11', overlaps and is sealed by gluing so as to straddle the membrane 28' and the edge of the opening 14'.

[0135] The membrane 28' is made of microporous, or the like, waterproof and air-permeable expanded polytetrafluoroethylene, e-PTFE for short. The membrane can be laminated with at least one supporting knit made of polymeric material, such as polyester or polyamide.

[0136] Herein, the terms front, rear, left, and right refer to directions relative to the footprint. Therefore, the word front denotes the direction toward the forefoot, the term rear denotes the direction toward the hindfoot, etc.

[0137] Figure 2 is a perspective and exploded view of a sole structure 1 according to the present invention. The sole structure 1 comprises a sole 10 provided with a breathable or pierced forefoot portion. Preferably, the sole 10 is made of a polymeric material, e.g., rubber, polyurethane (Pll), thermoplastic polyurethane (TPU), thermoplastic rubber (TR), EVA and the like, and has one or more through holes 11. The sole 10 can be composed of a single piece (one- piece sole), as in the solution shown in Figures 1-7 and 11-16, or two or more pieces, such as an assembly consisting of a midsole 50 joined to a tread 40 contacting the ground, as shown in Figures 5-10 and 17-21.

[0138] The sole 10 has a ground-contact bottom surface 12, and a top surface 13 which is coupled to an upper assembly (not shown) to obtain a finished shoe. A seat 14, having the function of housing a membrane 15, also referred to as a waterproof and breathable functional layer, is formed on the top surface 13 of the sole 10.

[0139] The seat 14 is basically a bas-relief of the top surface 13 of the sole 10. The depth of the seat 14 is such that the membrane 15 is housed so as to be flush with the top surface 13 of the sole 10, thus preventing the formation of a step. In other words, the top surface of the membrane 15 housed in the seat 14 is substantially coplanar with the top surface 13 of the sole 10. In case a membrane laminate is used, the top surface of the laminate will be coplanar with that of the sole. Preferably, the depth of the seat 14 is in the range of 0.5 to 20 mm. Alternatively, the sole 10 can be without the seat 14 and the membrane 15 can be arranged on the top surface 13, thus forming a step.

[0140] As mentioned, the sole structure 1 comprises also the membrane 15. The membrane 15 is optionally coupled to one or more protective and / or supporting layers, e.g., knits, felts, etc., not drawn for the sake of simplicity. A membrane 15 coupled to such protective and / or supporting layers constitutes a manufactured article known as laminate.

[0141] The membrane 15 used within the scope of the present invention is made of PFAS-free polymeric material, e.g., polyurethane, polyethylene, polypropylene, polyester and combinations thereof. Examples of well-known laminates are marketed under the trade names Sympatex® and Porelle®.

[0142] The membrane 15 is shaped following the shape of the sole 10 at the forefoot, for example by generating a negative (i.e., inward) offset of 10-14 mm of the inner profile 16' of the sole 10 at the side edge. In practice, the membrane 15 is made by die-cutting one or more layers of one or more polymeric materials / sheets, so that the membrane 15 has a shape corresponding to the forefoot of the sole 10 and complementary to the seat 14.

[0143] In the case of soles with a pointed shape, preferably the offset is increased to 15-20 mm at the toe of the sole 10: as a matter of fact, during certain phases of walking, the toe can be more stressed and experience has shown that, at the toe, the distance of the membrane 15 from the inner profile 16' of the sole 10 should preferably be increased compared to that at the side edges.

[0144] The longitudinal axis b is identified with the Brannock axis, or more simply as the axis AC defined in Standard ISO 20344:2004(E) in paragraph 5.3.2 (page 10).

[0145] The longitudinal extent of the membrane 15, and thus also of the breathable or pierced forefoot portion, is conveniently between 20% and 80% of the total length of the sole 10. The offsets thus obtained, being basically curved lines, are linked together by using radii of curvature usually between 2 and 20 mm, thereby obtaining a closed contour 17 that is the contour of the membrane 15, which can also be defined as first template.

[0146] The second template 18 of the corresponding seat 14 basically coincides with the first template 17 of the membrane 15; in practice, however, a minimum clearance, in the range of 0.1 -0.2 mm, is maintained between the templates 17 and 18 to facilitate the positioning of the membrane 15 inside the seat 14.

[0147] The sole structure 1 further comprises a reinforcing element 20 made of waterproof material, such as by shearing a sheet of polyvinyl chloride (PVC), Pll, TPU or EVA subsequently coupled to the membrane 15. As an alternative, the element 20 can be made by transfer, sublimation, pouring or co-molding according to known techniques.

[0148] The reinforcing element is preferably made of PVC with a thickness of about 0.5 mm.

[0149] The reinforcing element 20 overlaps to the membrane 15 and is joined thereto in a watertight manner to form a whole, a first assembly altogether denoted by the reference number 100. In the attached figures, the reinforcing element 20 overlaps the membrane 15 on its top surface but the assembly can also be made by placing the element 20 to overlap the membrane on its bottom surface, before gluing the membrane to the sole 10. As an alternative, the assembly 100 can be made with two inserts 20, one joined to the top surface of the membrane 15 and the other joined to the bottom surface of the membrane 15.

[0150] Another possibility is to stratify the assembly 100 by alternating a bottom membrane 15, a reinforcing element 20 and a top membrane 15. The two membranes 15 sandwich the reinforcing element 20. Preferably, these two membranes 15 have the same shape, that is, they are formed according to the same template. Alternatively, the extent of the top membrane can be larger to ensure better leveling with the edge of the respective seat.

[0151] The membrane 15 is glued to the sole 10 inside the seat 14 according to known techniques. In this first embodiment, the reinforcing element 20 has a dual function.

[0152] A first function is precisely that of reinforcement: a portion of the element 20 extends at the area of the membrane 15 which is most forced to flex during walking, which corresponds to the portion of the sole structure 1 that is subject to maximum flexing during walking. As mentioned above, this portion can be easily located without equipment by simply holding the sole structure in your hands and flexing it at about 1 / 3 of its length. In the following, the portion of maximum flexing will be identified in more detail by referring to the construction lines r, s, t.

[0153] A second function is to seal the membrane 15 to the sole 10: the reinforcing element 20 in fact also extends around the membrane 15, in particular it straddles the membrane 15 and the sole 10, being glued to both of them. Water, which could penetrate through the openings 11 and infiltrate between the membrane 15 and the sole 10, is prevented from entering the inside of the footwear equipped with the sole 10 thanks to the reinforcing element 20.

[0154] In practice, the reinforcing element 20 seals the membrane 15 to the sole 10 even when it does not straddle the membrane 15 and the sole 10 but is inside the seat 14. In the latter case, both the membrane 15 and the reinforcing element 20 are placed inside the seat 14 and the perimeter portion of the reinforcing element 20 that overhangs the membrane 15 acts as a seal bridge of the latter with the sole 10.

[0155] Referring to Figures 2, 3a and 3b, the reinforcing element 20, 20a, 20b has an outer contour 20' formed as a positive (i.e. , outward) offset whose value is preferably between 4 mm and 8 mm of the contour 17, or template 17, of the membrane 15. The entire portion of the reinforcing element 20, 20a, 20b between the outer contour 20' and the contour 17 of the membrane 15 is glued from above to the surface 13 of the sole 10, in the forefoot region, to seal the sole 10.

[0156] The reinforcing element 20, 20a, 20b leaves a first front area 21 and a second rear area 22 of the membrane 15 exposed.

[0157] In the example shown in Figure 3b, the reinforcing element 20a has an almost eight-like shaped. The membrane 15 is accessible through the areas 21 and 22, so as not to hinder the breathability of the sole structure 1 , since the reinforcing element 20a is waterproof and may be not breathable. In the example shown in Figure 3c, the reinforcing element 20b is a band. In the example shown in Figure 3d, the reinforcing element 20b is cross shaped.

[0158] Thus, in practice, the membrane 15 is a single element having the contour 17 (template 17) which is overlapped by the reinforcing element 20, 20a, 20b, which has an edge that extends beyond the contour 17 of the membrane 15 and which has the areas 21 and 22 through which water vapor can pass and pass through the membrane 15.

[0159] Figures 2, 3a and 4 show construction lines r, s, t, the meaning of which will now be explained with reference to Figure 3a which shows the contour of the sole 10 and the membrane 15, in a plan and top view, together with the wearer's foot bones.

[0160] The line of construction "s" and the line of construction "t" intersect each other at the point O lying on the plane containing the projection on the ground of the inner profile 16' of the sole 10, and are obtained from the line of construction "r" which identifies the flexing line of the foot and, for this reason, is also called the flexing line r.

[0161] The construction line r passes through the point B which represents the end of the first metatarsal facing the proximal phalanx of the big toe, and is directed toward the lateral foot. The construction line r passes forward (i.e., toward the toes) of the distal phalanx of the fifth toe, preferably tangential to the upper end thereof. In practice, the construction line r does not cross the fifth toe of the foot: in fact, the latter is hardly affected by the flexing of the foot during walking.

[0162] In practice, considering the total length of the sole structure 10 to be equal to L, the construction line r orthogonally intersects the longitudinal axis b at a point that is at the distance L / 3 from the toe of the sole structure 10.

[0163] This allows the construction line r that intersects the contour 17 (template 17) of the membrane 15 at point Y to be drawn.

[0164] The construction line s approximately bisects the proximal phalanx of the big toe, so that the distance between the point B and the construction line s, measured in parallel to the longitudinal axis b, which for simplicity is considered akin to the Brannock axis that bisects the foot in the forefoot-hindfoot direction, is about 15-20 mm for a men's foot size 42 (reference is to French sizes). The construction line s also intersects the contour (template) 17 of the membrane 15 at a point X substantially within the distal phalanx of the fourth finger (it may be tangent to the upper end of this phalanx, for example, or it may intersect the template 17 at approximately the center line of the phalanx itself).

[0165] In practice, the construction line s intersects the longitudinal axis b at a distance of about 15-20 mm (in men's size 42) from the point of intersection of the construction line r and the longitudinal axis b, toward the toe of the sole structure 10. The construction line s and the construction line r converge to the point O.

[0166] This allows the construction line s that intersects the construction line r at point O to be drawn.

[0167] To draw the construction line t intersecting the template 17 at the point Z, the process is as follows: X and Y are already known, and the arc YZ is drawn so that its length is equal to about half the length of the arc XY, thus obtaining the point Z. The construction line t can be easily drawn, since it also passes through the point O.

[0168] The relationship between the length of the arc XY and the length of the arc YZ, which can be expressed as follows:

[0169] LXY = 2»LYZ is obtained from experimental evidence, according to which: i) the arch XY extends along the region where the foot and the sole structure 1 have the maximum flexing stress, and ii) the fourth toe, as seen above in relation to the fifth toe, is almost excluded from flexing during walking because of the anatomy of the human foot, and therefore the arch YZ thus sized allows a reasonable margin of safety where the flexing stress, while taking a lower value than the arch XY, still makes it preferable to reinforce the membrane 15.

[0170] The construction lines s, t, which diverge from the point 0, delimit the portion of the sole structure subject to maximum flexing. Alternatively, the construction lines s, t can be parallel, or nearly parallel, to the construction line t which intersects the longitudinal axis b at a point 12-15 mm rearward of the construction line r.

[0171] Once the construction lines s and t are obtained, the areas 21 and 22 can be dimensioned.

[0172] With reference to Figures 2, 3a and 3b, the edge of the first area 21 , forward of the reinforcing element 20, 20a, 20b:

[0173] - is substantially tangent to the construction line s,

[0174] - extends sideways and toward the toe of the sole 10 while remaining nearly parallel to the contour 17 of the membrane 15, with a negative, i.e., inward, offset preferably between 4 and 8 mm in value.

[0175] The edge of the first area 21 can be defined by straight or curvilinear segments properly linked, for example, by radii of curvature generally between 2 and 20 mm, thus obtaining a closed contour with no sharp edges that defines the perimeter of the first area 21.

[0176] Similarly, the edge of the second area 22, rearward of the reinforcing element 20, 20a, 20b:

[0177] - is substantially tangent to the construction line t,

[0178] - extends sideways and toward the hindfoot of the sole 10 while remaining nearly parallel to the contour 17 of the membrane 15, with a negative, i.e., inward, offset preferably between 4 and 8 mm in value.

[0179] The edge of the second area 22 can be defined by straight or curvilinear segments properly linked, for example, by radii of curvature generally between 2 and 20 mm, thus obtaining a closed contour with no sharp edges that defines the perimeter of the second area 22.

[0180] In the embodiment just described and shown in the figures, there are two areas 21 and 22 but this choice is not limiting: for example, one of the areas 21 , 22 or both the areas 21 , 22 can be split into two additional areas separated by a portion of the reinforcing element 20b, as shown in figure 3d.

[0181] Figure 3b shows, in plan view and from above, the first assembly 100 formed by the membrane 15 and the reinforcing element 20a almost eight-like shaped.

[0182] Figure 3c shows an embodiment 101 of the assembly formed by the membrane 15 and the reinforcing element 20b, in the shape of a band. The element 20b according to this different embodiment has a front side 31 facing the toes, a rear side 33 opposite the front side 31 , an inner side 34 facing the medial foot, and an outer side 32 facing the lateral foot.

[0183] The front side 31 and the back side 33 are segments of the construction lines s and t, respectively, the outer side 32 basically coincides with the arc XZ whereas the inner side 34 basically coincides with the arc between the other intersection points of the construction lines s and t with the contour (template) 17 of the membrane 15. The outer side 32 is usually longer than the inner side 34 because of the construction described above.

[0184] In this embodiment, the element 20b intercepts two areas 61 , 62 on the membrane 15, and specifically a front area 61 positioned at the front, toward the toe of the assembly 101 , and a rear area 62 positioned at the back, opposite the front area 61 .

[0185] The two areas 61 , 62 of the membrane 15 not covered by the reinforcing element 20b can in turn be partitioned into multiple areas 6T, 61", 62', 62" by appropriately shaping the element 20b, e.g., by giving the element 20b a cross shape, as shown for the assembly 103 in Figure 3d, and by intercepting two left and right front windows 6T and 61", respectively, and two left and right rear windows 62', 62", respectively. Figure 3e shows a section of the sole structure 1 in the vertical section plane A'-A' in Figure 3b; this is a section plane that intercepts the first assembly 100 precisely at the portion subject to greatest flexing, between the construction lines s, t, where the reinforcing element 20a is located. In the example shown, the membrane 15 is fully housed in the seat 14 and the reinforcing element 20a overlaps the membrane 15 and is joined thereto it in a watertight manner, and overhangs the edge of membrane 15 on the top surface of the sole 10, to which the first assembly 100 is sealed. As can be seen in Figure 3e, at this section, the reinforcing element 20a extends continuously, i.e. without discontinuities, over the entire width of membrane 15.

[0186] Figure 3f shows a section of the sole structure 1 on the vertical section plane A-A in Figure 3b; this is a section plane that intercepts the first assembly 100 exactly at the breathable portion not covered by the reinforcing element 20a, forward of the construction line s. The membrane 15 is fully housed in the seat 14 but is not capped on top by the reinforcing element 20a, which extends only straddling the edge of the membrane 15 and the edge of the seat 14 to make a sealed coupling. The membrane 15 thus fulfills the function of allowing vapor phase sweat to escape from the inside of the footwear to the outside through the through-holes 11.

[0187] Figure 3g is a schematic plan and top view of another first assembly 104. In this example, the membrane 15 is coupled to a reinforcing element 20a which is placed on top of the membrane 15 itself and is provided with a plurality of through eyelets 6T", 62"', which are grouped in an area forward of the construction line s and in an area rearward of the construction line t, respectively. The through eyelets 6T", 62"' can be traversed by vapor phase sweat to escape through the membrane 15. The through eyelets 6T", 62'" are equivalent to the areas 21 , 22, 61 , 62 left exposed in the other versions of the assembly 100, 101 , 103.

[0188] Figure 3h is an exploded, cross-sectional view of the portion of the sole structure equipped with the first assembly shown in Figure 3g, considered in the plane of vertical section C-C, thus forward of the construction line s. As can be seen, compared with the previously described embodiments, in this embodiment the reinforcing element 20a is preferably between two and twenty times thicker than in the embodiment of Figs. 3e-3f, and the depth of the seat

[0189] 14 almost corresponds to the assembly 104, so that when the assembly 104 is inserted into the seat 14, it remains substantially flush with its edge.

[0190] Figure 3i is a cross sectional view of the assembly 104, considered in the plane C’-C’ of figure 3g. This is an intermediate portion between the construction lines s and t, i.e., the portion subject to greatest flexing. In this portion, the reinforcing element 20a extends without openings from side to side, i.e., from right to left of the figure (i.e., from the lateral foot to the medial foot or vice versa), to cover the entire extent of membrane 15.

[0191] Figure 3m is a schematic plan and top view of an alternative version of the first assembly 105, which is similar to the assembly 101 in Figure 3c but comprises two membranes 15a and 15b. The membrane 15a is forward of the reinforcing element 20b, which is a band, and the membrane 15b is rearward of the reinforcing element 20b. The dashed lines 3T and 33' denote the overlap of the element 20b on the bottom edge of the front membrane 15a and the top edge of the rear membrane 15b.

[0192] Figure 4 shows in plan, from above, Figures 3b and 3c superimposed on a part of Figure 3a, particularly the forefoot region. In this figure, the differences between the different embodiments of the first assembly denoted by 100, 101 , 103, 104, 105, respectively, can be appreciated. In fact, as can be seen, the surface of the front area 21 is smaller than the surface of the area 61 , and similarly, the surface of the rear area 22 is smaller than the surface of the area 62. In general, however, all the areas 21 , 22, 61 , and 62 can have the same size: for example, the element 20a of the first assembly 100 is wider than the membrane 15 in order to act as a seal between the membrane and the sole, whereas the element 20b of the first assembly 101 is as wide as the membrane

[0193] 15 to allow a direct seal between the membrane 15 and the sole 10. However, it should be noted that in the solutions 100, 101 , 103, 104, 105 at least one portion of the element 20a, 20b extends from the inner side to the outer side of the sole 10, i.e., across the entire width, from the left intrados to the right intrados, advantageously at the area intercepted by the construction lines from the contour 17 of the membrane 15, area that corresponds to the area most subject to flexing during walking. The reinforcing element 20, 20a, 20b does not cover the two front areas 21 or 61 and rear areas 22 or 62, so as not to impede the membrane 15 from working properly, for temperatureregulating the footwear.

[0194] Therefore, the reinforcing element 20, 20a, 20b overlaps the membrane 15 only where it is required to maximize the mechanical strength of the first assembly 100, 101 , 103, 104, without jeopardizing the functionality of the membrane 15.

[0195] The reinforcing element 20, 20a, 20b can be made in one piece or can comprise several parts, disjointed at first and then joined together.

[0196] As needed, the reinforcing element 20, 20a, 20b can be joined to the membrane 15 and the resulting pre-assembled assembly 100, 101 , 103, 104 is subsequently joined to the sole 10. Alternatively, the reinforcing element 20, 20a, 20b can be joined to the membrane 15 after the latter, in turn, has been joined or positioned to / on the sole 10.

[0197] Figure 5 shows a rear perspective view of a left shoe LS and a vertical section plane cutting the forefoot region where the assembly 101 formed by the membrane 15 and the reinforcing element 20b is provided.

[0198] Figure 6 is a cross section view of a sole structure 1 of the shoe LS shown in figure 5.

[0199] Figure 7 is a perspective and exploded view of the shoe LS shown in figure 5.

[0200] In this case, the seat 14 accommodates an optional protective layer 19 made, for example, of water-resistant polyester or polyamide felt, which protects from below the membrane and the reinforcing element 20b from foreign bodies that may penetrate through the openings 11. The seat 14 is formed as described above. The membrane 15 is obtained by die-cutting one or more sheets as described above, so that the contour 17 of the membrane 15 extends with positive offset on the edge of the seat 14. Preferably, the overlap is about 4-8 mm.

[0201] In this embodiment, the reinforcing element 20b is not used to seal the membrane 15 to the sole 10: the membrane 15 is directly glued to the sole 10 at the edge of the seat 14 thus making a waterproof seal, and the reinforcing element 20b extends transversely, i.e. , from right to left across the entire width of the seat 14, below the membrane 15, resulting in the areas 61 and 62 left exposed.

[0202] In general, the same result can be achieved by using two separate membranes 15a and 15b positioned one forward of the reinforcing element 20b and one rearward of the reinforcing element 20b, as shown in Figure 3m.

[0203] In addition, the reinforcing element 20b can be made with longitudinal extensions, such as a cross shape, in order to partition the areas 61 and 62 each into two right and left areas, resulting in the reinforcement of the assembly 101 at the longitudinal axis b, as shown in Figure 3d.

[0204] In general, a protective layer 19 can be used in all embodiments described herein. Additional protective layers 19 can be added also on top of the membrane 15 and / or the reinforcing element 20, 20a, 20b.

[0205] Figure 8 shows a rear perspective view of a left shoe LS and a vertical section plane which cuts the forefoot region where the assembly 101 , which is formed by the membrane 15 and the reinforcing element 20b and which is now positioned between a midsole 50 and the respective tread 40, is provided.

[0206] Figure 9 is a cross section view of a sole structure 1 of the shoe LS shown in figure 8.

[0207] Figure 10 is a perspective and exploded view of the shoe LS shown in figure 8.

[0208] The tread 40 and the midsole 50 are provided with breathing openings denoted by 11 and 51 , respectively. The seat 14 for the membrane 15 is formed on the surface of the midsole 50 facing the tread 40, basically on the bottom surface of the midsole 50, in the use layout. In this case, the seat 14 is formed so as to leave an edge of about 10 mm useful for gluing the midsole 50 to the tread 40; preferably, the seat 14 has a longitudinal extent between 20% and 80% of the total length of the sole 10.

[0209] One or more of the breathing openings 51 may overlap the reinforcing element 20b: in this case, since the material of the reinforcing element 20b is waterproof and not breathable, these openings perform in any case the function of lightening the midsole 50 while preventing excessive weighting of the sole structure 1 . In this case, the function of the reinforcing element 20b is not to seal the membrane 15 to the tread 40.

[0210] Waterproofness is achieved by gluing the reinforcing element 20b to the membrane 15 in a watertight manner, thus forming the assembly 101 which is sealed, in turn, to the midsole 50 over a width of 4-8 mm on the inner edge of the seat 14.

[0211] Also in the solution shown in Figures 8-10, the membrane 15 is made in a single piece but, as already mentioned in relation to the solution shown in Figures 5-7 and as shown in Figure 3m, it is possible to make the assembly in multiple portions.

[0212] Moreover, also in this solution, the areas 61 and 62 can be further portioned by longitudinal extensions of the reinforcing element 20b that overlap the membrane 15 at the longitudinal axis b.

[0213] Figure 11 shows a rear perspective view of a left shoe LS and a vertical section plane which cuts the forefoot region where the assembly 101 , which is formed by the membrane 15 and the reinforcing element 20b and which is now joined to the sole 10 formed by injection molding directly on an upper assembly, is provided.

[0214] Figure 12 is a cross section view of a sole structure 1 of the shoe LS shown in figure 11. Figure 13 is a perspective and exploded view of the shoe LS shown in figure 11 .

[0215] In this case, the element 20b is joined to the membrane 15 in a watertight manner according to one of the ways previously explained, and the resulting assembly 101 is joined perimetrically to the upper 30 by the seam 24, thus obtaining the upper assembly. The upper assembly may include a lining, not shown, to be oriented towards the user's foot, and a functional layer of the upper, also not shown, to make a fully waterproof shoe.

[0216] When the molding is complete, the membrane 15 is monolithically joined to the sole 10: the injected polymeric material that, when solidified, forms the sole 10, adheres to the exposed perimeter portion of both the membrane 15 and the reinforcing element 20b (or the assembly 101 ) by a margin of 4-8 mm, thus forming a waterproof seal. In this case too, the seat 14, which has lower extent than the membrane 15, accommodates a protective layer 19, e.g. made of water-resistant polyester felt, which protects the membrane 15 from below against foreign bodies which may penetrate through the openings 11. The seat 14 can be formed as described above or it can be made around the protective layer 19 during the molding step: the protective layer 19 can be loaded into the mold used for the injection process or joined to the assembly 101. The protective layer 19 is sized according to a negative offset of 4-8 mm of the membrane contour.

[0217] Preferably, the contour (template) 17 of the membrane 15 is formed with an offset towards the outside of the seat 14 so as to provide outside the seam 24, between the membrane 15 and the sole 10, an interface (in practice a sealing margin) preferably between 4 and 8 mm. In this case, the reinforcing element 20b does not act as sealing means but it contributes to the seal: the membrane 15 is sealed to the sole 10 by the injected polymeric material that makes up the sole itself.

[0218] Figure 13 also shows a portion of the insole 15' which is joined to the membrane 15 and faces the portion of the sole 10 that is without the openings 11.

[0219] The considerations made previously about the possibility of making the assembly 101 with two membranes 15a and 15b positioned forward and rearward in relation to the reinforcing element 20b, as shown in Figure 3m, and about the possibility of making the element 20b in the shape of a cross, as shown in Figure 3d, in order to intercept portions to the right and left of the longitudinal axis b on the membrane 15, or the membranes 15a, 15b, also apply to this solution.

[0220] Figure 14 shows a rear perspective view of a left shoe LS and a vertical section plane which cuts the forefoot region where the assembly 101 , formed by the membrane 15 and the reinforcing element 20b, is provided, the assembly 101 being now co-molded with a sole 10, for example by an injection molding process.

[0221] Figure 15 is a cross section view of a sole structure 1 of the shoe LS shown in figure 14.

[0222] Figure 16 is a perspective and exploded view of the shoe LS shown in figure 14.

[0223] The element 20b is joined to the membrane 15 in a watertight manner according to one of the previously described ways, and the resulting assembly 101 is loaded onto an injection mold, thereby resulting, after injection, monolithically joined and sealed to the sole 10. The seat 14 accommodates a protective layer 19 made, for example, of water-resistant polyester or polyamide felt, which protects from below the membrane 15 against foreign bodies that may penetrate through the openings 11 .

[0224] The seat 14 can be formed as described above and since the seat 14 has an extent smaller than the extent of the membrane 15, i.e. , the contour 17 of the membrane 15 surrounds the edge of the seat 14 (it is basically a positive offset of the seat 14), the membrane 15 overlaps the edge of the seat 14 over about 4-8 mm.

[0225] In contrast to the embodiment shown in Figures 5-7, after the injection process, the top surface of the sole 10 is almost at the same level as the assembly 101 ; in other words, between the top surface of the sole 10 and the reinforcing member 20b there are no steps that would reduce comfort. In fact, there is a first seat 14a for the protective layer 19, if any, and a second seat 14b for the membrane 15.

[0226] In this embodiment too, the function of the reinforcing element 20b is not to seal the membrane 15 but to contribute to the sealing, as the membrane 15 is sealed to the sole 10 by the injected polymeric material that composes the sole itself. The reinforcing element 20b, being below the membrane 15, is sealed to the sole 10 by the injected polymeric material.

[0227] The construction shown in Figures 8-10 can also be made by using the assembly denoted by 102, as shown in Figures 17-21.

[0228] Figure 17 shows a rear perspective view of a left shoe LS and two vertical section planes X-X and Y-Y which cut the forefoot region where a second assembly 102 formed by the membrane 15 and the midsole 50 is provided.

[0229] Figure 18 is a cross section view of the sole structure 1 of the shoe LS shown in figure 17, considered in the section plane X-X.

[0230] Figure 19 is a cross section view of the sole structure 1 of the shoe LS shown in figure 17, considered in the section plane B-B.

[0231] Figure 20 is a plan bottom view of the midsole 50 of the sole structure 1 of the shoe LS shown in figure 17.

[0232] Figure 21 is a perspective and exploded view of the shoe LS shown in figure 17.

[0233] As can be seen, in this embodiment the midsole 50 itself constitutes the reinforcing element. In particular, a portion of the midsole 50 performs the function of a reinforcing element and it extends transversely, from left to right in Figs. 18-20 (i.e., from the medial foot ito the lateral foot), between the previously described construction lines s and t, i.e., at the flexing axis r.

[0234] In fact, in line with the definition of midsole given in Standard EN ISO 19952:2005, item 106, page 18, previously referred to, actually the reinforcing element 20a of the preceding embodiments rightly falls within the definition of midsole. Conversely, therefore, the midsole 50 itself can be defined as a reinforcing element, i.e. , the equivalence midsole = reinforcing element applies, since both the midsole 50 and the reinforcing element 20, 20a, 20b of the preceding embodiments are placed between the sole 10 and the insole, which (in almost all cases) is part of the upper assembly to which the sole structure 1 is joined.

[0235] Therefore, the midsole 50 performs the task of mechanically reinforcing the membrane 15, thus limiting its wear due to repeated flexing caused by the deformation imparted to the sole structure 1 by the user during walking.

[0236] The same process that would allow the areas 21 and 22 described above to be formed is used to form the contours 2T and 22', which are used to encircle the areas within which the through-openings 51 shall be placed.

[0237] In this embodiment, the membrane 15 is joined to the midsole 50, for example, by gluing the inside of the seat 14 over 4-8 mm, thus forming a waterproof seal that makes the sole structure waterproof. Then the midsole 50 is joined to the tread 40, preferably by gluing.

[0238] Since no gluing is provided between the membrane 15 and the tread 40, vapor phase sweat can escape from the holes 11 in the tread which are located at the portion of the midsole 50 without openings 51 .

[0239] In all embodiments of the assembly 100-105, in order for the reinforcing element 20, 20a, 20b, 50 to function as reinforcement for the membrane 15 to increase the flexing resistance thereof, the former is joined to the latter in a monolithic and watertight manner and thus at least perimetrically with respect to the flexing region i.e. the region between the construction lines s and t, preferably by gluing or co-molding, by coating, by ultrasounds, etc. Preferably, the reinforcing element 20, 20a, 20b, 50 is joined to the membrane 15 in a watertight manner at least in the region between the construction lines s and t, and preferably over the entire region between the construction lines s and t. In addition, the reinforcing element 20, 20a, 20b, 50 even in embodiments in which it does not exert a function of sealing the membrane 15 to the sole 10, still constitutes an emergency seal that, if the membrane 15 breaks, ensures waterproofness in a neighborhood of the region to which it is joined: this is possible because the reinforcing element is made of waterproof material.

[0240] In general, in all embodiments 100-105, two or more membranes 15 can be used, e.g., a first membrane 15a, 151 positioned forward of the element, and a second membrane 15b, 152 positioned rearward of the element, as shown in Figures 3d and 3m.

[0241] Clearly, if two membranes 15a, 151 , 15b, 152 were to be used, two seats 14 could also be made, one forward of the flexing axis, the other rearward of the flexing axis. In this case, the two seats 14 will have complementary shape with respect to the two membranes 15a, 151 , 15b, 152.

[0242] In addition to the embodiments shown in the figures, the present invention can be implemented also in the following ways.

[0243] The seat 14, in which the first assembly 100, 101 , 103, 104, 105 can be housed, can be formed on the top surface of the tread 40. The tread 40 sealed to the first assembly 100, 101 , 103, 104, 105 in a waterproof manner is then joined, e.g. glued, to a midsole 50 to complete the sole structure 1 .

[0244] Alternatively, the seat 14, in which at least one membrane 15 is housed, is formed on the top surface of the tread 40. The midsole 50 is formed as in the embodiment of Figs. 17-21 but without the seat 14 which, as mentioned, is formed on the tread 40. The at least one membrane 15 and the midsole 50 are joined in a watertight manner.

[0245] The element 20 can also consist of a waterproof material comprising a heat-activated adhesive: examples of such materials available on the market are, for example, the film 3218 marketed by the firm Bemis Associates Inc., or XAF 36.004 Puro from the firm Collano AG, or the double-sided heat-seal polyurethane film called STX200 from the firm Seatex, or even PRX 1733 / A film from the firm FaitPlast. The sole structure 1 made according to the present invention has a flexing resistance preferably equal to at least 30000 cycles, more preferably equal to at least 300000 cycles, even more preferably equal to at least 2000000 cycles, determined according to the method set forth in Chapter 8.4.2 of Standard ISO 20344:2011. After being subjected to the flexing cycles, the sole structure 1 is still waterproof according to the definition of waterproofness given above, referring to the sole 10.

Claims

CLAIMS1. A footwear sole structure (1 ) comprising:(i) a sole (10) extending lengthwise along a longitudinal axis (b) in the forefoot-hindfoot direction, wherein the sole (10) comprises a breathable or pierced forefoot portion,(ii) an assembly (100-105) comprising- at least one waterproof and breathable membrane (15, 151 ) extending at least partially at the breathable or pierced forefoot portion, and- a reinforcing element (20, 20a, 20b, 20c) made of waterproof material and at least partially overlapping the at least one membrane (15, 151 ) and joined thereto, in a watertight manner, wherein said assembly (100-105) is sealed in a waterproof way to the sole (10), characterized in that said at least one portion of the reinforcing element (20, 20a, 20b, 20c) extends transversely to the longitudinal axis (b) at the breathable or pierced forefoot portion subject to maximum flexing and leaves at least one area (21 , 21’, 61 , 61’, 61”, 22, 22’, 62, 62’, 62”) of the at least one membrane (15, 151) exposed.

2. Sole structure (1) according to claim 1 , wherein the reinforcing element (20, 20a, 20b, 20c) leaves the following exposed, i.e. does not overlap the at least one membrane (15, 151 ):- at least one first area (21 , 2T, 61 , 61’, 61”) of the at least one membrane (15, 151), being forward of the reinforcing element (20, 20a, 20b, 20c), and- at least one second area (22, 22’, 62, 62’, 62”) of the same membrane (15, 151 ) or of at least one second membrane (15b, 152), being rearward of the reinforcing element (20, 20a, 20b, 20c).

3. Sole structure (1) according to claim 1 or claim 2, wherein the reinforcing element (20, 20a, 20b, 20c) extends across at least the entire width of the at least one membrane.

4. Sole structure (1 ) according to any one of the preceding claims, wherein the reinforcing element (20, 20a, 20b, 20c) extends from the left edge to the right edge of the breathable or pierced forefoot portion, without discontinuities.

5. Sole structure (1 ) according to any one of the preceding claims, wherein the reinforcing element (20, 20a, 20b, 20c) overlaps the at least one membrane (15, 151), above or below the same.

6. Sole structure (1 ) according to any one of the preceding claims, wherein the reinforcing element (20, 20a, 20b, 20c) is sandwiched between two membranes (15, 151 , 15b, 152).

7. Sole structure (1 ) according to any one of the preceding claims, wherein the reinforcing element (20, 20a, 20b, 20c) is not breathable and / or is devoid of holes.

8. Sole structure (1 ) according to any one of preceding claims 1-6, wherein the reinforcing element (20, 20a, 20b, 20c) is glued or joined in a watertight manner to the at least one membrane (15, 151 ) at the entire extent of the reinforcing element (20, 20a, 20b, 20c).

9. Sole structure (1 ) according to any one of preceding claims 1-8, wherein the reinforcing element (20, 20a, 20b, 20c) leaves at least one first area (21 , 21’, 61 , 61’, 61”) and at least one second area (22, 22’, 62, 62’, 62”) of the at least one membrane (15, 151 , 15b, 152) exposed and wherein the reinforcing element (20, 20a, 20b, 20c) extends longitudinally, rearward of said first area (21 , 21’, 61 , 61’, 61”) and / or forward of said second area (22, 22’, 62, 62’, 62”) for a length at least sufficient to keep the breathable or pierced forefoot portion subject to maximum flexing within the area of the reinforcing element (20, 20a, 20b, 20c).

10. Sole structure (1 ) according to any one of preceding claims 1-9, wherein the reinforcing element (20, 20a, 20b, 20c) leaves at least one first area (21 , 21’, 61 , 61’, 61”) and at least one second area (22, 22’, 62, 62’, 62”) of the at least one membrane (15, 151 , 15b, 152) exposed and wherein a portion ofthe reinforcing element (20, 20a, 20b, 20c) extends around said first area (21 , 21’, 61 , 61’, 61”) and around said second area (22, 22’, 62, 62’, 62”).

11. Sole structure (1 ) according to claim 10, wherein the reinforcing element (20, 20a, 20b, 20c) is joined in a watertight manner to the at least one membrane (15, 151 ) at the perimeter of the breathable or pierced forefoot portion and possibly also at the perimeter of said first area (21 , 2T, 61 , 61 ’, 61 ”) and said second area (22, 22’, 62, 62’, 62”).

12. Sole structure (1) according to any one of the preceding claims, wherein:- the sole (10) is monolithic and the reinforcing element (20, 20a, 20b) is an element distinct from the sole (10) and the at least one membrane (15, 151 ), or- the sole (10) is obtained by joining a midsole (50) to the respective tread (40), the midsole (50) and tread (40) are provided with a breathable or pierced forefoot portion and the reinforcing element (20c) is a waterproof portion of the midsole (50), at least partially overlapping the at least one membrane (15, 151 ) and joined thereto in a watertight manner.

13. Sole structure (1 ) according to claim 12, wherein the assembly formed by the at least one membrane (15, 151 ) and the reinforcing element (20, 20a, 20b) distinct from the sole (10) is defined as first assembly, and the assembly formed by the at least one membrane (15, 151 ) and the reinforcing element (20c) integral with the midsole (50) is defined as second assembly.

14. Sole structure (1 ) according to claim 13, wherein:- a seat (14, 14b) is formed on the top surface of the sole (10) and the first assembly (100, 101 , 103, 104, 105) is completely housed inside the seat (14), or the at least one membrane (15, 151) is housed in the seat (14) and the reinforcing element (20, 20a, 20b) extends at least partially around the at least one membrane (15, 151 ) outside the seat (14), or- the first assembly (100, 101 , 103, 104, 105) is joined to the top surface of the sole (10), or- a seat (14), inside which the first assembly (101 ) is housed, is formed on the bottom surface of the midsole (50) and the midsole (50), with the first assembly (101 ), is joined to a tread (40); or- the first pre-assembled assembly (100, 101 , 103, 104, 105) is loaded onto a mold to make the sole (10) by injection, or- a seat (14), inside which the at least one membrane (15, 151 ) is housed, is formed on the top surface of the sole (10) and the sole (10) is joined to, or injected onto, an upper assembly provided at the bottom with the reinforcing element (20b) joined in a watertight manner to the at least one membrane (15, 151 ), so that the at least one membrane (15, 151 ) and the reinforcing element (20b) define the first assembly (101 ) together, or- a seat (14), inside which the first assembly (100, 101 , 103, 104, 105) is housed, is formed on the top surface of the tread (40) and the tread (40), with the first assembly (100, 101 , 103, 104, 105), is joined to a midsole (50).

15. Sole structure (1 ) according to claim 13, wherein:- a seat (14), inside which the reinforcing element (20c) extends and inside which the at least one membrane (15, 151 ) is housed, is formed on the bottom surface of the midsole (50), so that the at least one membrane (15, 151 ) and the reinforcing element (20c) define the second assembly (102) together, and the midsole (50) with the second assembly (102) is joined to a tread (40); or- a seat (14), inside which the at least one membrane (15, 151 ) is housed, is formed on the top surface of the tread (40), and the reinforcing element (20c) is defined on the bottom surface of the midsole (50), so that the at least one membrane (15, 151 ) and the reinforcing element (20c) define the second assembly (102) together whenever the tread (40) is joined to the midsole (50).

16. Sole structure (1) according to any one of the preceding claims, wherein the at least one membrane (15, 15a, 15b, 151 , 152) is made of aPFAS-free polymeric material or is a laminate made of several PFAS-free materials.

17. Sole structure (1) according to any one of the preceding claims, wherein the at least one membrane (15, 15a, 15b, 151 , 152) is a sheet made of a material selected from polyurethane, polyethylene, polypropylene, polyester and combinations thereof or is a laminate made of several sheets of one or more of these materials.

18. Sole structure (1) according to any one of the preceding claims, wherein the at least one membrane (15, 15a, 151 , 152) extends over the entire breathable or pierced forefoot portion.

19. Sole structure (1) according to any one of the preceding claims, wherein the longitudinal extent of the assembly (100-105) is between 20% and 80% of the total length of the sole (10).

20. Sole structure (1) according to any one of the preceding claims, wherein, considering the footprint of the sole (10) on the ground and considering the anatomy of the foot of the user, three construction lines (r, s, t) are defined on the plane of the footprint:- construction line r which passes through point B, which point B represents the end of the first metatarsal facing the proximal phalanx of the big toe, and which intersects the outer contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) at a point Y by passing forward of the distal phalanx of the fifth toe, preferably tangential to the upper end thereof;- construction line s which bisects the proximal phalanx of the big toe, forward of point B and at a distance from point B equal to about 15-20 mm, measured in parallel to the Brannock axis, and which intersects the outer contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) at a point X substantially within the distal phalanx of the fourth toe;- construction line t which extends from the intersection point O between the construction line r and the construction line s and which intersects the outer contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) at a point Z,and wherein the length (LYZ) of the contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) between points Y and Z is equal to half the length (LXY) of the contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) between the points X and Y, i.e.LXY = 2»LYZ, wherein the reinforcing element (20, 20a, 20b, 20c) extends between the s and t construction lines.

21. Sole structure (1) according to any one of the preceding claims, wherein said breathable or pierced forefoot portion subject to maximum flexing corresponds to a portion of the sole structure (1 ) which extends at, or straddles, the flexing line defined in Standard ISO 20344:2004(E), paragraph 8.4, page 64.

22. Sole structure (1) according to any one of the preceding claims, wherein the total length of the sole (10) along said longitudinal axis (b) is equal to L, and wherein said breathable or pierced forefoot portion subject to maximum flexing corresponds to a portion of the sole structure (1 ) which extends at, or straddles, the flexing line r, defined as the construction line r, which intersects the longitudinal axis (b) orthogonally at the point which is at a distance equal to L / 3 from the toe of the sole (10).

23. Sole structure (1) according to any one of the preceding claims, wherein, considering the footprint of the sole (10) on the ground and wherein the total length of the sole (10) along said longitudinal axis (b) is equal to L, three construction lines (r, s, t) are defined on the plane of the footprint:- construction line r, which intersects orthogonally the longitudinal axis (b) at the point that is at a distance equal to L / 3 from the toe of the sole (10) and intersects, at a point Y, the outer contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152);- construction line s, which intersects the longitudinal axis (b) at a point that in men's size 42 is 15-20 mm forward of the construction line r, and intersects, at a point X, the outer contour (17) of the at least one membrane (15,15a, 15b, 151 , 152);- construction line t, which intersects the longitudinal axis (b) at a point that in men's size 42 is 12-15 mm rearward of the construction line r, and intersects, at a point Z, the outer contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152), and wherein the length (LYZ) of the contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) between the points Y and Z is equal to half the length (LXY) of the contour (17) of the at least one membrane (15, 15a, 15b, 151 , 152) between the points X and Y, that isLXY = 2* LYZ, wherein the reinforcing element (20, 20a, 20b, 20c) extends between the s and t construction lines.

24. Sole structure (1 ) according to the preceding claim, wherein the construction lines s and t are parallel, or nearly parallel, or diverge from a point 0 outside the sole structure.

25. Sole structure (1 ) according to any one of claims 20-24, wherein the at least one membrane (15, 15a, 151 ) defines at least one area (21 , 61 ) permeable to water vapor between the construction line s and the front contour (17) of the at least one membrane (15, 15a, 151 ), and wherein the at least one membrane (15, 15a, 151) or a second membrane (15b, 152) defines an area (22, 62) permeable to water vapor between the construction line t and the rear contour (17) of the at least one membrane (15b, 152).

26. A method of manufacturing a footwear sole structure (1 ), which comprises providing:(i) a sole (10) having a breathable or pierced forefoot portion and a dimension running along a longitudinal axis (b) in forefoot-hindfoot direction,(ii) an assembly (100-105) comprising at least one waterproof and breathable membrane (15, 151 ) and a reinforcing element (20, 20a, 20b, 20c) made of waterproof material,and which comprises:- positioning the at least one membrane (15, 151) at least partially at the breathable or pierced forefoot portion,- overlapping at least one part of the reinforcing element (20, 20a, 20b, 20c) on the at least one membrane (15, 151 ) and joining it to the latter in a watertight manner,- sealing said assembly (100-105) to the sole (10) in a waterproof way, characterized by arranging a portion of the reinforcing element (20, 20a, 20b, 20c) transversely to the longitudinal axis (b) at the breathable or pierced forefoot portion subject to maximum flexing, and by positioning the reinforcing element (20, 20a, 20b, 20c) so as to leave at least one area (21 , 2T, 61 , 61’, 61”) of the at least one first membrane (15, 151 ) exposed.

27. Method according to claim 26, wherein the reinforcing element (20, 20a, 20b, 20c) is positioned, with respect to the at least one membrane (15, 151 ), so as to leave exposed:- at least one first area (21 , 2T, 61 , 61’, 61”) being forward of the reinforcing element (20, 20a, 20b, 20c), at the at least one membrane (15, 151), and- at least one second area (22, 22’, 62, 62’, 62”) being rearward of the reinforcing element (20, 20a, 20b, 20c), at the same membrane (15, 151 ) or at least one second membrane (15b, 152).

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