Sole, in particular outer sole for footwear and footwear provided with said sole

Abstract

Sole, in particular an outer sole, in which: the said sole has at least one part that is deformable in the direction of the width to allow the width and / or the perimeter of the sole itself to be varied at least partially adapting the sole to the width, or lateral-lateral dimensions of the foot and especially of the area of the foot in front of the arch of the foot, i.e. the area of foot of the user having a maximum width named also metatarsal area. The invention is also directed to a shoe comprising an upper and the said sole, the said shoe being alternatively provided with an upper which covers a predominant part of the foot or a shoe with an upper which leaves a predominant part of the foot uncovered.

Description

[0001] Sole, in particular outer sole for footwear and footwear provided with said sole

[0002] DESCRIPTION TEXT

[0003] The present invention is directed to a sole for footwear, in particular an external sole, which sole has at least one part that is deformable in the direction of the width to allow the width and / or perimeter of the sole itself to be varied at least partially adapting the sole to the width dimensions, i.e. lateral -lateral dimensions, of the foot of the user's plantar area and in particular in the are of the foot having the largest width.

[0004] In this description and in the claims, the plantar area refers to or includes the part of the foot in front of the plantar arch, i.e. the area of the metatarsals and phalanges.

[0005] Generally the soles of footwear have different mechanical characteristics that contribute to the comfort of the user. However, the soles and in particular the outer soles must have mechanical resistance characteristics because they constitute the contact interface with the ground and through them all the forces exerted by the user are discharged both due to the user's own weight and during walking .

[0006] This characteristic of the soles is in contrast with the needs of adaptability of the shape and dimensions of the shoe to the shape and dimensions of the user's foot which would require materials for the soles which have sufficient elastic deformability in order to yield elastically to the pressure stresses in sense of widening and / or lengthening exerted by the user's foot.

[0007] Various solutions are known at the state of the art which allow an adaptation of the shoe and, in particular, of the dimensions of the sole to the dimensions of a user's foot thanks to a particular construction of the sole itself.

[0008] From document W02006087737A1 a shoe is known which includes a sole of the type described at the beginning. The shoe described in this document comprises an upper fixed to a sole, and a mounting insole removably inserted into the shoe above said sole. The sole has at least one deformable part which is configured in such a way as to allow the width and / or length and / or perimeter of the sole to be varied at least partially to therefore adapt the sole to the dimensions of the user's plantar area. This shoe further comprises in combination members for maintaining the sole in a preferred deformed position adapted to the size of the foot of the user of the shoe. These members for maintaining the sole in a preferred deformed position include at least one substantially rigid element, which is fixed to the insole in such a position that when said insole is inserted into the shoe, said element is positioned in correspondence with at least a portion of the deformable part of the sole. This rigid element is shaped and sized in such a way as to maintain the sole in said preferred deformed position.

[0009] Document WO02051273A2 describes a sole which is made in such a way as to allow adaptation to dimensional variations of a user's foot and in particular to dimensional variations in the direction of the width of the foot. The outer sole has one or more longitudinally elongated through openings such as slots or similar which are sealed by elements of corresponding shape. The external sole in which the longitudinal slots are made is made of a first elastomeric material having a specific hardness, while the filling material of the slots is an elastomeric material identical or compatible with said first elastomeric material and has a second hardness lower than that of said first elastomeric material or a lower specific weight. The first portion of material and the second portion of material are molded together during the manufacturing process, such as a two-component injection molding or coextrusion process. The second portion of material has a "U" shaped channel which extends longitudinally and which essentially functions as a bellows to allow the expansion of the slots under the stress of the foot, while maintaining the said slots selalingly closed towards the soil. The construction envisaged by this document requires only mutual contact for the adhesion between the two elastomers which are of relatively limited extension and which in the long run may present cracks. Furthermore, even the filling material of the slots, in order to allow the transversal expansion effect, is made relatively thin and therefore represents a weakened area with respect to damage due to wear.

[0010] The present invention therefore aims at creating a sole which allows for excellent adaptability to the dimensions of the foot and in particular in which said adaptation takes place thanks to an automatic elastic deformation under the expansion pressure exerted by the foot itself and a return to the narrowest condition when the foot undergoes a reduction in size.

[0011] The present invention aims to obtain this automatic dimensional adaptation without generating areas of weakening of the sole structure and guaranteeing a high mechanical resistance of the sole itself to repeated mechanical stresses.

[0012] It is worth remembering here that the feet are subject for physiological reasons to variations in size due to swelling and also to subsequent reduction in size. Therefore, a shoe that is perfectly suited to a foot can within a short time be either too narrow or too wide depending on the dimensional variations of the foot. These dimensional increases or decreases also occur over the course of a day or a few hours and require elastic dimensional adaptability of the sole both in the sense of expansion and in the sense of shrinkage.

[0013] The invention solves the problem posed with a sole, in particular an outer sole of the type described at the beginning, in which: the said sole has at least one part that is deformable in the direction of the width to allow the width and / or the perimeter of the sole itself to be varied at least partially adapting the sole to the width, or lateral-lateral dimensions of the foot and especially of the area of the foot in front of the arch of the foot, or of the area of the foot of the user named metatarsal area and in any case of the area of the foot having the largest width and in which the said sole includes:

[0014] - a first part of the sole having a first pre-established hardness and / or a first elastic modulus and / or a first density and a second part of the sole having a second hardness and / or a second elastic modulus and / or a second density which second hardness is lower than said first hardness and / or which second elastic modulus is smaller than said first elastic modulus and / or which second density is smaller than the said first density;

[0015] - the said first part of the sole forming the contact surface with the ground and being provided in the area coinciding with the sole of the foot, i.e. the front part of the foot, i.e. the area starting from the arch of the foot up to the front end of the foot of a plurality of passing slots at least some of which are substantially parallel to each other and oriented in the antero-posterior direction of the sole;

[0016] - the said second part being constituted by an insert superimposed on the side of the said plantar area of the first part of the sole opposite to the side of contact with the ground and which insert is constituted by a flattened element which extends continuously, i.e. without interruptions, for substantially the entire extension of said plantar area of said first part of the sole, thereby closing all the slots provided in said first part of the sole, on the side of said first part of the sole opposite to the side in contact with the ground and for their entire length and width;

[0017] - the said second part of the sole having on the upper side, opposite to that of contact with the said first part of the sole, grooves of pre-established depth which are essentially coinciding and congruent with the through slots of the said first part of the sole;

[0018] - said second sole part being fixed to said first sole part by chemical and / or physical adhesion. The term chemi cal -physical adhesion refers to all methods of coupling layers of plastic materials, both the ones that involve direct adhesion through the application of heat and / or compression of the materials of the two layers together and the ones that involve the use of adhesive materials, and event fixing methods that involve mechanical means of mutual crimping.

[0019] According to one embodiment, the said second part of the sole has ridges on the side facing the said first part of the sole, in correspondence with the said grooves coinciding with the said passing slots of the second part of the sole, which ridges are coincident and congruent with the said passing slots and have a thickness such as to penetrate inside said passing slots for at least part of the thickness of said first part of the sole in correspondence with said grooves.

[0020] The width of the said ridges of the second part of the sole corresponds essentially to the width of the corresponding slot provided in the said first part of the sole.

[0021] According to a variant embodiment, the protrusion of the said projections beyond the contact surface of the said second part of the sole against the said first part of the sole is of such a size as to substantially compensate for the reduction in thickness of the said second part of the sole in correspondence with the said grooves.

[0022] A variant embodiment provides that the said projections penetrate inside the through slots of the said first part of the sole for the entire thickness of the same and that they connect without interruption in the continuity of the material to a layer of the said second part of the sole which overlaps at least partially or completely the external surface of the first part of the sole facing the ground. Optionally the said layer of the second part of the sole has shape and / or dimensions corresponding to the ones of the insert forming the said second part of the sole on the side opposite to the side facing the ground.

[0023] Thanks to the characteristics specified above, the sole according to the present invention has a transversal extensibility such that it automatically adapts to the width of the foot, also following the variations of the dimensions of the foot occurring throughout the day.

[0024] The first part of the sole which is more rigid or has a greater elastic modulus allows an elastic widening thanks to the plurality of through slots oriented in the longitudinal direction of the same, while the second part of the sole closes the said pass-through slots towards the upper part of the shoe and thanks to its lower hardness and / or its lower elastic modulus allows the width deformations of the through slots to be followed without increasing the rigidity and / or the total elastic modulus of the complete sole in relation to a width deformation maintaining at the same time the adhesion of the second part of the sole to said first part of the sole without compromising the sealing of said through slots even after a long period of use.

[0025] The behavior relating to the overall rigidity of the sole and / or the features of elastic deformability, or resistance to transverse deformation of the sole, are easily calibrated by operating alternatively or in combination both on the intrinsic characteristics of rigidity and elastic modulus of the elastomeric materials used for the two parts of the sole, and on the dimensions of the said first sole part and of the said second sole part, such as for example the thicknesses of the said sole parts and / or the dimensions of the through slots of the grooves and of the ridges.

[0026] The provision of grooves on the side of the second part of the sole opposite to that of contact with the first part of the sole and of projections on the surface of the said second part of the sole which penetrate in the said through slots for part of their depth allows to form at the said grooves and at the coinciding projections areas with a transversal deformation behavior which simulates or is substantially identical to that of a bellows or similar, but which on the other hand allows to have a substantial thickness of the material in correspondence with the through slots and keep the thickness of the second part of the sole substantially constant along the entire extension.

[0027] The provision of a second part of the sole which extends without interruptions for substantially the entire extension of the plantar area of the first part of the sole provided with the said through slots allows to have a contact surface between the said first part of the sole and the said second part of the sole which substantially corresponds to the entire extension of the said second part of the sole, except at the said passing slots, whereby the chemi cal / phy si cal adhesion between the said two parts of the sole is guaranteed for a large surface. This makes the overall integrity of the sole more resistant even after long periods of use, avoiding the formation of tears between the two parts of the sole which compromise the outward seal of the sole itself.

[0028] According to a further advantageous feature which can be provided in combination or in sub-combination with one or more of the previous embodiments or variants, the overall thickness of the first part of the sole is of the order of magnitude of the overall thickness of the second part of the sole or slightly less than the overall thickness of said second part of the sole, the thickness of said second part of the sole corresponding to a value from 1 to 4 times the thickness of the first part of the sole depending on the type of shoe in which the sole is intended to be used. Still according to a further feature which can be provided in combination or in subcombination with one or more of the previous embodiments and / or variants and / or of the previous features, in the areas of the said second part of the sole not coinciding with the grooves, said second sole part has a plurality of recesses with a depth corresponding to a part of the overall thickness of said second sole part and optionally different with respect to the depth of the grooves coinciding with the through slots of the first sole part.

[0029] According to an embodiment which can also be provided in combination or in subcombination with one or more of the previous features and / or embodiments and / or variants, the first part of the sole presents a housing seat for the said second part of the sole in which the thickness of the said first part of the sole is reduced compared to the thickness of a perimeter band delimiting the said housing and the said perimeter band forming a sort of perimeter frame delimiting the said housing.

[0030] In combination with the said housing, in the areas not provided with grooves and / or recesses, the second part of the sole can have a thickness substantially corresponding to the reduction in thickness of the first part of the sole in the said housing and / or optionally even smaller or greater.

[0031] With reference to a preferred embodiment, the first part of the sole has at least two passing slots in the plantar area which follow at a certain distance the curvilinear trend of the adjacent perimeter edge of the said first part of the sole and which end at a certain distance from the front end of said first part of the sole remaining separated from each other.

[0032] The said at least two through slots are arranged on opposite sides of a longitudinal, central or median axis of the first part of the sole and at a substantially identical distance from the corresponding adjacent lateral edge of the said first part of the sole.

[0033] According to a variant embodiment, the said first part of the sole is provided with four passing slots, which are provided in pairs on opposite sides of the said median or central longitudinal axis of the first part of the sole, the slots of each pair both substantially following the shape of the adjacent perimeter edge of the sole and being substantially parallel to each other and each slot being separated from the others.

[0034] In a variant embodiment the said at least two slots or at least part or all of the said through slots on one side of the central or median longitudinal axis of the first part of the sole connect with the corresponding slots on the other side of the central or median longitudinal axis of the first part of the sole with a section that follows the perimeter edge of the first part of the sole along the front end and without interruptions. Thanks to the above features, each or at least some of the through slots are "U" shaped and each depart from the end of the plantar area facing the arch of the foot on one side of the central longitudinal axis A continuing without interruption towards the front end, along said front end and backwards from it towards the end of the plantar area adjacent to the arch of the foot following substantially parallel the shape of the perimeter edge of the front half of the sole.

[0035] Still according to a further feature, which can also be provided in combination or in sub-combination with one or more of the previous features and / or embodiments and / or variants, the recesses in the thickness of the said second part of the sole can be distributed along one or more rows extending along lines substantially parallel to said grooves so as to form one or more rows of recesses in the areas interposed between said grooves of said second part of the sole.

[0036] According to yet a further feature, the sole according to one or more of the previous embodiments and / or variants and / or features requires that it be provided in combination with a so-called assembly insole, which is constituted by a rigid sheet-like element cut to size and with a corresponding shape to the plan shape of the entire sole, the first part of the sole being provided with a perimeter fin which protrudes above the surface of the upper side of the sole forming a perimeter containment frame and the said assembly insole being of such dimensions as to accommodate the inside the said perimeter containment frame, while the said assembly insole has in the plantar area substantially coinciding with the said second part of the sole at least two or more through slots which are substantially coincident with one or more or with all the said grooves and / or the said rows of recesses provided adjacent to the said grooves in the said second part of the sole.

[0037] The said assembly insole has a hardness and / or an elastic modulus greater than the hardness and / or the elastic modulus of the said first part of the sole.

[0038] This embodiment is particularly suitable for the use of the sole according to the present invention in footwear having a substantially closed upper or which upper covers a predominant part of the foot.

[0039] In an alternative embodiment, intended for use in particular with open footwear, i.e. with an upper that covers a small part of the foot, leaving the predominant part of the foot uncovered, an assembly insole is not provided, but the internal sole supporting the foot is made in the form of a material element having a hardness lower than that of the first part of the sole and / or an elastic modulus lower than that of the first part of the sole and substantially similar or of the order of magnitude of those of the second part of the sole, which internal sole has a thickness greater than the protrusion of said perimeter fin which forms the containment frame of the internal sole and whose support surface of the foot is three-dimensionally shaped, corresponding to the anatomy of the foot itself.

[0040] Furthermore, according to a further feature on the side facing the upper side of the first and second sole parts coupled together, the said internal sole presents at least two or more longitudinal grooves and one or more of which longitudinal grooves or all of the said grooves are coinciding with a corresponding longitudinal groove of the ones provided in the second part of the sole and which present a shape substantially identical and congruent to the ones of the corresponding groove in said second part of the sole.

[0041] According to yet a further characteristic, the said second part of the sole presents at least a further recess for locking in position and for anti-slip of the said interna sole relatively to the said first and / or second part of the sole and / or for centering the said internal sole with respect to the said second part of the sole, while the said internal sole presents a corresponding locking and centering rib for each of said recesses for locking in position and relative anti-slip securing and / or centering of said internal sole.

[0042] Yet another possible further characteristic which gives greater elasticity in the sense of compression of the internal sole provides that in the thickness of the same there is a plurality of recesses which from the side in contact with the combination of the first and second part of the sole and which recesses penetrate to a depth equal to part of the overall thickness of said internal sole and are distributed with a pre-established density and with a pre-established order along part or the entire extension of said internal sole.

[0043] Advantageously, the elastomeric materials for the manufacture of the sole parts and the inner sole can be made of natural rubber, synthetic rubber and / or plastic polymers.

[0044] Typically, materials from the family of thermoplastic elastomers, also known as thermoplastic rubbers (TPR), are used to manufacture one-piece or combined soles.

[0045] TPR material is synthesized using block copolymers such as SBS (styrene-butadiene-styrene). Thermoplastic rubber can also be described as a thermoplastic elastomer. However, when comparing TPR to TPE, typically TPEs are mostly made from SEBS (styrene-ethylene- butadiene-styrene) based polymers, while TPRs are made from SBS polymers.

[0046] There are several types of thermoplastic rubber, including:

[0047] Styrene block copolymers (TPE-s)

[0048] Thermoplastic polyolefins (TPE-o or TPO)

[0049] Vulcanized thermoplastics (TPE-v or TPV)

[0050] Thermoplastic polyurethanes (TPU) Thermoplastic copolyester (TPE-E)

[0051] Thermoplastic polyamides (TPE-A)

[0052] Unclassified thermoplastic elastomers (TPZ).

[0053] As regards the characteristics of the material of the first part of the sole, the hardness is preferably between 30 and 70 A according to the SATRA TM205:2016 test performed at a temperature of 23°C±2°C and at a relative humidity of 50±10 %, preferably 50 to 60 A.

[0054] As regards the density of the material of the first part of the sole in relation to the volume displacement, this is between 0.8g / cm3 and 1.0g / cm3, preferably between 0.9 and 0.998g / cm3 according to the SATRA TM134 test: 1998 performed at a temperature of 23°C±2°C and a relative humidity of 50±10%.

[0055] Relative to the second part of the sole, the hardness of the elastomeric material provided for this second part is between 10 and 30 A, preferably between 15 and 21 A according to the SATRA TM205:2016 test performed at a temperature of 23°C±2°C and at a relative humidity of 50±10%.

[0056] As regards the density of the material of the second part of the sole in relation to the volume displacement, this is between 0.6g / cm3 and 0.8g / cm3, preferably between 0.65 and 0.75g / cm3 according to the SATRA TM134 test : 1998 performed at a temperature of 23°C±2°C and a relative humidity of 50±10%.

[0057] The abrasion resistance value of the first part of the sole relative to the contact surface with the ground is between 100 and 200 mm3, preferably between 120 and 160 mm3, measured according to the DIN SATRA TM174:2016 test performed at a temperature of 23° C±2°C and at a relative humidity of 50±10%.

[0058] The elastic resistance values of the complete sole, namely of the said first part of the sole to which the second part of the sole is fixed in a definitive manner are measured according to the Bata-PFOl test.

[0059] This test involves measuring the force necessary to extend the width of the sole in the said metatarsal area by approximately 3mm, i.e. the measurement corresponding to the increase of one shoe size compared to the measurement at rest, i.e. in the absence of traction force. The sole is tightened at two opposite points of the widest metatarsal area and a mechanical traction force is exerted to obtain a widening of the sole equal to three millimeters corresponding to an increase of one size. Upon reaching the extension of the said three millimeters, the force exerted to obtain this increase in width is measured.

[0060] The test is performed at a temperature of 23°C±2°C and at a relative humidity of 50±10%, are between 8.0 and UN, preferably between 9.3 and 10.3N. The invention also refers to a shoe comprising an upper which is fixed to a sole made according to one or more of the characteristics and / or of the embodiments and / or of the variants described above, said shoe being made according to one of the following two alternatives: an alternative in which the upper is shaped so as to cover a predominant part of the foot; an alternative in which the upper is shaped so as to leave a predominant part of the foot uncovered and / or is made up of thin bands or containment bands in the style of a slipper or similar.

[0061] These and other features and advantages of the present invention will appear more clearly from the following description of some exemplary embodiments illustrated in the attached drawings in which:

[0062] Figure 1 shows an upper plan view of the side in contact with the ground and on the side opposite to that of contact with the ground of a sole according to an embodiment of the invention.

[0063] Figure 2 shows a plan view of the sole according to figure 1 on the side opposite to that of contact with the ground and of a corresponding mounting insole.

[0064] Figure 3 shows a section of the sole according to figures 1 and 2 and according to a plane transverse and perpendicular to the side of contact of the sole with the ground.

[0065] Figures 4 and 5 show an enlarged detail of the section according to figure 3 with the sole respectively in a rest condition, i.e. not stressed by a traction in the direction of transversal widening, and with the sole subjected to a stress of transverse expansion or traction in transversal widening direction.

[0066] Figure 6 and figure 7 show two plan views on the side of the sole resting on the ground, respectively of two further embodiments in which the slots are continuously connected to each other also at the front end of the first part of the sole and wherein said second sole part also extends so as to overlap with said first sole part on the side in contact with the ground.

[0067] Figure 8 shows the mutual contact sides of an external sole and an internal sole according to an embodiment of the present invention, the external sole and the internal sole being configured for use in a sandal, a slipper or a shoe in which the upper leaves a majority of the foot exposed.

[0068] Figure 9 shows the side in contact with the ground and the foot support side of the external and internal sole respectively according to the embodiment of figure 8. Figure 10 is a view similar to that of figure 8 with the internal sole and the external sole in a position of partial approach to each other in the direction of mutual coupling.

[0069] With reference to figures 1 to 5, they show a first embodiment of the sole according to the present invention, in particular of an external sole.

[0070] Number 1 indicates a first part of the sole which is intended to form the contact surface with the ground indicated with 101.

[0071] The plan shape of the sole essentially presents two halves, one at the front and one at the rear. The front one substantially corresponds to the sole of the foot, i.e. the area of the foot that goes from the arch of the foot to the front end and which substantially coincides with the area of the metatarsals and phalanges, while the rear one coincides with the area of the heel and the cuboid. The front and rear parts are connected by an intermediate area centered substantially with the arch of the foot and which coincides with the area of the cuneiforms and partly with that of the cuboid.

[0072] In the front half of the area of the first part of the sole 1, two pairs of slots 201 are provided. These are made passing from side to side of the said first part of the sole 1 and each pair is arranged on one side of two opposite sides of a longitudinal axis central part of the first part of the sole 1 and which is indicated with A in figure 1.

[0073] The two slots 201 of each pair are made arched and with a shape substantially parallel to each other and following the curvature of the adjacent lateral perimeter edge 301 of the first part of the sole 1.

[0074] The width of the slots 201 can be constant along their entire length or the said slots can have a fusiform shape, i.e. the width of the same is greater in a central area and progressively narrows towards the ends with substantially an identical progression of narrowing towards the said two ends at which the width can also be identical between the said two ends of the slots 201.

[0075] According to the embodiment of figures 1 to 5, at the front end each slot 201 is at a certain distance from the end of the other slots and in particular of the corresponding slot on the opposite side of said central longitudinal axis A.

[0076] As shown in the variant of figure 6, each slot 201 can extend without interruption along the corresponding perimeter edge of the front area of said first part of the sole, connecting the two corresponding slots on the opposite sides of the central longitudinal axis A without interruption with a section of the slot extending along the front perimeter edge section of the first part of the sole 1 and substantially parallel to it. Therefore, as shown in figure 6, the slots take on a U shape which is open towards the rear half of the first part of the sole and which is instead closed at the front end of said first part of the sole.

[0077] As shown in the figures and optionally, the slots can connect with their free ends to recessed grooves 401 provided on the side in contact with the ground and which have a partial depth compared to the overall thickness of the first part of the sole. Furthermore, transversal arcuate grooves 501 which cross the grooves 401 and / or the slots 201 can also optionally be provided.

[0078] The slots 201 are closed by means of an insert 2 which is coupled by chemical and / or physical adhesion to the side of the first part of the sole opposite to that in contact with the ground.

[0079] The insert 2 is formed by a substantially flattened shaped piece and has a plan shape substantially similar to that of the front half of the first part of the sole and constitutes a second part of the sole. The extension of the said insert which forms the said second part of the sole 2 is slightly smaller than the extension in plan of the front half of the said first part of the sole 1 so that in the coupled condition a perimeter band of the indicated frame is left free from the said insert with 601.

[0080] Furthermore, the extension is such that the insert, or the second part of the sole made up of it, covers and seals all said slots 201 for their entire extension in width and length.

[0081] As is evident from figures 1 and 2, on the side of the insert 2 opposite to that of adhesion to the first part of the sole 1, a groove 102 is provided for one or more of the slots 201 provided in the said first part of the sole 1. The grooves 102 have a depth equal to only a part of the overall thickness of the insert 2.

[0082] In one embodiment, in the coupled condition of the insert 2 to the first part of the sole 1, at least a part of the said grooves 102 or all the said grooves 102 coincide respectively with a corresponding slot 201. Preferably the grooves 102 have an extension and a shape substantially identical or perfectly congruent with that of the corresponding slot.

[0083] According to another possible embodiment which is illustrated in the figures, in the areas adjacent to the grooves 102, a plurality of recesses 202 are made in the said insert 2.

[0084] In an embodiment such as the one illustrated, the said recesses 202 are distributed on one or more longitudinal rows which extend parallel to the adjacent grooves 102.

[0085] As can be seen from figures 3 to 5, in the area coinciding with the slots 201 of the first part of sole 1, the said second part of sole, namely the said insert 2, has longitudinal projections 302 on the side facing the said first part of sole 1 which longitudinal projections coincide with a corresponding slot 201 and which present such a protrusion from the adhesion side of the insert 2 against the first part of the sole 1, such that the said projections 302 penetrate inside the corresponding slot 201 only for a part of the thickness of the first part of the sole corresponding to the slots 201.

[0086] The projections 302 have identical shape and dimensions in plan with the shape and dimensions in plan of the corresponding slot 201 and coincide with a corresponding groove 102 of the insert.

[0087] As shown in figure 3, thanks to this configuration of the insert 2, the projections 302 allow the thickness of the material of the insert 2 to be recovered in the area of the grooves 102 and generate a sort of extensible bellows element or similar.

[0088] According to another feature which appears evident from the section of figure 3, in the thickness of the first part of the sole 1 and in the area of the front part of the said first part of the sole 1 there is a housing 701 for the said insert 2 consisting of a recess which has shape and dimensions in plan corresponding to those of the insert 2 and a lateral containment perimeter frame which forms the said perimeter band 601.

[0089] The depth of said housing 701 substantially corresponds to the thickness of the insert 2 in the areas without said projections, said grooves and said recesses.

[0090] However, executive variations can be envisaged in which the said thickness of the insert 2 is greater or less than the depth of the housing 701.

[0091] Furthermore, as is evident from figures 4 and 5, the projections 302 of the insert 2 are not coupled so as to be fixed to the corresponding surfaces of the perimeter edges which delimit the corresponding slots 201. In particular, figure 5 shows that in the case of a stress in the direction of transversal extension of the sole, the lateral edges of the projections 302 are free to move away from the surfaces formed by the perimeter edges of the corresponding slot 201, while the contact surfaces interposed between the slots 201 of the first part of the sole to the said insert 2 remain perfectly fixed to each other in a watertight manner, and also the lateral perimeter edges of the said insert 2 against the lateral edges that delimit the housing 701 and form the perimeter containment frame 601.

[0092] With reference to figure 6, this variant is made in a substantially identical way compared to the previous embodiment according to figures 1 to 5, while with reference to figure 7, the insert material also extends beyond the slots 201 on the side of the first part of sole 1 facing the ground and overlaps the surface of the said side of the first part of the sole 1 completely with a layer 5 of substantially identical shape and dimensions to those that the insert 2 presents on the opposite side of the said first part of the sole, thus forming a layer of direct contact with the ground of said second part of the sole. This allows the sturdiness of the sole to be further increased in relation to breakages or cracks which can compromise the integrity of the closure of the slots 201 towards the outside.

[0093] As is clear from figures 1 and 2, the rear half of the first part of the sole 1 has a combination of stiffening ribs 801 arranged in crossed directions and which form the support surface of an assembly insole indicated with 3 in figure 2.

[0094] Along the perimeter edge, preferably along the entire perimeter edge, the first part of the sole has a perimeter flap 901 closed on itself which delimits the housing compartment of the said assembly insole 3.

[0095] In the embodiment of figure 2, the assembly insole is made up of a sheet-like piece of relatively rigid material, i.e. which has a greater hardness and / or a greater elastic modulus than the first part of the sole.

[0096] The said assembly insole constitutes the element for fixing the internal sole and the upper to the first part of the sole 1.

[0097] As shown in figure 2, the assembly insole 3 can have one or more continuous or discontinuous through slots 103, at least some of which coincide with the grooves 102 of the insert 2 and / or with the rows of recesses 202 provided in said insert.

[0098] The through slots 103 provided in the assembly insole 3 can also be in a greater number than the grooves 102 and / or the rows of recesses 202 in the insert 2 and can also have extensions in length different from those of the said grooves and the said rows of recesses . Furthermore, said assembly insole 3 can also have through slots 103 provided in a position that does not coincide with said grooves 102 and / or said rows of recesses 202.

[0099] As is evident from the figures, the coupling of the second part of the sole, or of the insert 2 to the first part of the sole 1, can take place using various known techniques.

[0100] In particular, the creation of the first and second parts of the sole takes place through double injection of two different thermoplastic rubbers (TPR), one of which has a first hardness and / or a first elastic modulus and the second of which has a second hardness and / or a second elastic modulus which are different from each other corresponding to the hardness and / or elastic modulus characteristics foreseen for the said two parts of the sole. The double injection takes place for example at a temperature of approximately 160°C.

[0101] Alternatively, it is also possible to provide other types of couplings as the preferred one disclosed above such as, for example, a coupling through compression and simultaneous heating of the said two parts of the sole.

[0102] Figures 8 to 10 show a further embodiment of the sole according to the present invention. In these figures, parts that are the same or have the same function as those in the previous example will be indicated with the same reference numbers used for the previous embodiment.

[0103] While the previous embodiment is particularly suitable for the manufacture of footwear with an upper that covers a predominant part or the entire foot, this embodiment is particularly suitable for the manufacture of footwear which leaves a preponderant part of the foot uncovered and which presents only some bands or bands or pockets that surround the foot as in the case of sandals, slippers or other types of substantially open footwear.

[0104] While the external part of the sole is formed by a first sole part 1 and a second sole part 2, which are made substantially similarly to the one or more executive variants described for the same parts with reference to the previous executive form of figures 1 a 7, in this embodiment the assembly insole is replaced by an internal sole in which the said assembly insole is integrated thanks to a particular conformation of the said internal sole. This internal sole is indicated with the number 4 and has an upper side which forms the surface, preferably three-dimensionally and anatomically shaped, to support the foot and a lower side intended to be coupled against the side of the external sole opposite to the contact side with the ground.

[0105] The term external sole being defined as the combination of the said first part of the sole 1 with the said second part of the sole 2, i.e. the said insert 2.

[0106] The said lower side of the internal sole 4 has grooves 104 at least some of which or each of which is intended to be positioned in coincidence with a corresponding groove 102 of the insert 2 which together with the first part of the sole 1 forms the external sole.

[0107] The said grooves 104 or at least some of these have a shape and / or dimensions substantially identical to those of the corresponding groove 102 provided in the insert 2.

[0108] However, similarly to what is provided for the assembly insole 3, grooves 104 which do not coincide with the grooves 102 of the insert 2 and / or grooves 104 which coincide or do not coincide with a corresponding row of recesses 202 of the insert 2 can also be provided.

[0109] In addition to the grooves 104, the said internal sole presents on the side of contact against the combination of insert 2 and first part of sole 1 a plurality of recesses 204 which are distributed according to a pre-established design and a pre-established density in the areas not occupied by the grooves 104 and over the entire extension of the inner sole 4.

[0110] The grooves 104 and / or the recesses 204 have a depth that is less than the overall thickness of the internal sole 4, so they do not open in correspondence with the side of said internal sole supporting the foot.

[0111] According to yet a further characteristic, on the side of the internal sole 4 in contact with the combination of insert 2 and first part of sole 1, one or more projections are provided to lock the position of said internal sole 4 to said combination of insert 2 and first part of sole

[0112] 1. These projections are provided in a position coinciding with a corresponding engagement seat, such as a recess or similar provided in the thickness of at least the insert 2.

[0113] In the embodiment of figures 7 to 9, in the central area of the contact side of the internal sole to the combination of insert 2 and first part of the solei, said internal sole 4 has a longitudinal median rib 304 having a pre-established length and a pre-established thickness, as well as a protrusion beyond the contact surface of the internal sole 4 with the said combination of insert 2 and first part of sole 1, such that it is intended to cooperate with a corresponding engagement seat provided as a groove in the thickness of the insert 2 and indicated with 502, whose depth is less than the thickness of the insert 2.

[0114] The combination of rib 304 and engagement seat 502 forms a locking member, locking in the relative position the two parts and which prevents mutual sliding both longitudinally and lateral and which helps as an additional coupling member of the internal sole 4 to the outer sole the perimeter frame 901 which overlaps externally on the perimeter edge of the internal sole 4, forming a housing for the containment of said internal sole 4.

[0115] As regards the materials used, the present invention involves the use of elastomers in the form of natural rubber, synthetic rubber, plastic materials or a combination of these materials .

[0116] Typical and non-limiting examples of these materials consist of thermoplastic rubbers as indicated above.

[0117] As regards the hardness and elastic modulus values for the first part of the sole 1 for the insert 2 and for the internal sole 4, these are preferably set in such a way that the first part of the sole 1 has a hardness and an elastic modulus greater than the second part of the sole, i.e. the insert

[0118] 2. The internal sole and the insert 2 can have hardness and / or elastic modulus values substantially identical to each other.

[0119] When an assembly insole 3 is provided, this is made of a material whose hardness and elastic modulus are greater than those of the first part of the sole.

[0120] An example of a sole according to the present invention includes: a first part of the sole consisting of a thermoplastic rubber having a first hardness and / or a first elastic modulus and / or a first density; a second part of the sole made of a thermoplastic rubber having a second hardness and / or a second elastic modulus and / or a second density lower respectively than said first hardness, said first elastic modulus and said first density; the first and second parts of the sole being produced by double injection into a mold at a temperature of no less than 160°C.

[0121] With reference to the thicknesses of the first part of the sole and the second part of the sole, these also depend on the type of material used. In general, and regardless of the material, the thicknesses are generally between 2mm and 10mm or more for the first part of the sole and for the second part of the sole.

[0122] The assembly insole 3 generally has thicknesses in the order of magnitude from 1 to 3mm, while the internal sole according to the present invention has a minimum thickness of 2mm to 5mm and a maximum thickness of 15 to 25mm depending on the area in which it is thickness is measured due to the three-dimensional conformation of the support surface of the foot corresponding to the anatomy of the foot itself.

[0123] As regards the width of the slots, in one embodiment this is preferably between 1 and 10mm, preferably between 2 and 4mm.

[0124] Alternatively or in combination with the above measurements, in one embodiment, the diameters of the recesses 202 can vary from 1 to 5mm and the depths from 2 to 5mm depending on the kind of sole or on the kind of shoe for which the sole has been made.

[0125] Alternatively or in combination with the above measurements, in one embodiment, the width of the grooves 102 is between 2 and 8mm, in particular between 4 and 6mm and the depth at the deepest point is between 2 and 10mm, preferably of of the order of 3 mm depending on the thickness chosen for the insert 2.

[0126] Alternatively or in combination with one or more of the embodiments set out above, the diameters of the recesses 204 in the internal sole 4 can vary from 5 to 10mm and the depths from 5 to 15mm depending on the thickness of said internal sole 4.

[0127] Alternatively or in combination with the above measurements, in one embodiment, the width of the grooves 104 is between 4 and 15mm, in particular of the order of 10mm and the depth at the deepest point is between 5 and 20mm, preferably of the order of 10mm depending on the thickness chosen for the inner sole 4.

[0128] The aforementioned dimensional indications are to be considered not restrictive, but indicative and depend both on the type of material used and on the thicknesses used for the various parts of the external and internal sole.

Claims

CLAIMS1. Sole, in particular an outer sole, in which: the said sole has at least one part that is deformable in the direction of the width to allow the width and / or the perimeter of the sole itself to be varied at least partially adapting the sole to the width, or lateral -lateral dimensions of the foot and especially of the area of the foot in front of the arch of the foot, or of the plantar area of the foot of the user and in which the said sole includes:- a first part of sole (1) having a first pre-established hardness and / or a first elastic modulus and / or a first density and a second part of sole (2) having a second hardness and / or a second elastic modulus and / or a second density which second hardness is lower than said first hardness and / or which second elastic modulus is less than said first elastic modulus and / or which second density is less the said first density;- the said first part of the sole (1) forming the contact surface with the ground and being provided in the area coinciding with the sole of the foot, i.e. the front part of the foot, i.e. the area starting from the arch of the foot up to the extremity front of the foot with a plurality of through slots (201) at least some of which are substantially parallel to each other and oriented in the antero-posterior direction of the sole;- the said second part of the sole (2) being constituted by an insert superimposed on the side of the said plantar area of the said first part of the sole (1) opposite to the side of contact with the ground and which insert (2) is constituted by a flattened element which extends continuously, i.e. without interruptions, for substantially the entire extension of the said plantar area of the said first part of the sole (1) closing all the said through slots (201) provided in the said first part of the sole (1 ), on the side of said first part of the sole (1) opposite to the side in contact with the ground and for their entire length and width;- the said second part of the sole (2) presenting on the upper side, opposite to that of contact with the said first part of the sole (1) one or more grooves (102) of pre- established depth one or at least some or all of which are essentially coincident and congruent with the said through slots (201) of said first part of the sole (1);- said second sole part (2) being fixed to said first sole part by chemical and / or physical adhesion.

2. Sole according to claim 1, in which the said second part of the sole (2) has projections (302) in correspondence with the said grooves (102) coinciding with the said through slotsprojections (302) are coincident and congruent with the said through slots (201) and have a thickness such as to penetrate inside the said through slots (201) for at least a part of the thickness of the said first part of the sole (1) at the said through slots (201).

3. Sole according to claim 2, in which the protrusion of the said projections (302) beyond the contact surface of the said second part of the sole (2) against the said first part of the sole (1) is of such a size as to substantially compensate for the reduction in thickness of said second part of sole (2) at the said grooves (102).

4. Sole according to claims 2 or 3, in which the said projections (302) penetrate inside the through slots (201) of the first part of the sole (1) for the entire thickness thereof and are connected without interruption in continuity of the material to a layer (5) of said second sole part which overlaps at least partially or completely on the external surface of the first sole part(1) facing the ground.

5. Sole according to one or more of the previous claims, wherein the overall thickness of the first sole part (1) is of the order of magnitude of the overall thickness of the second sole part(2) or slightly less than the overall thickness of said second part of the sole (2), optionally to the extent that is included in the range from 5% to 20% less than the overall thickness of the second part of the sole (2).

6. Sole according to one or more of the previous claims, in which, in the areas of the said second part of the sole (2) not coinciding with the grooves (102), the said second part of the sole presents a plurality of recesses (202 ) with a depth corresponding to a part of the overall thickness of said second sole part (2) and optionally different from the depth of the grooves (102) coinciding with the through slots (201) of the first sole part (1).

7. Sole according to one or more of the previous claims, in which the first part of the sole (1) has a housing seat for the said second part of the sole (2) in the shape of a recess in which the thickness of the said first part of the sole (1) is reduced compared to the thickness of a perimeter band (601) delimiting the said housing and the said perimeter band forming a sort of perimeter frame delimiting the said housing.

8. Sole according to claim 7, in which in combination with said housing, in the areas not provided with grooves (102) and / or recesses (202), the second part of sole (2) has a thickness substantially corresponding to the reduction thickness of the first part of the sole (1) in said housing and / or optionally also smaller or larger.

9. Sole according to one or more of the previous claims, in which the first part of the sole (1) has at least two passing slots (201) in the plantar area which follow at a certain distance the curvilinear shape of the adjacent perimeter edge (301) of the said first part of the sole (1) and which end at a certain distance from the front end of the said first part of the sole (1) remaining separated from each other, the said at least two through slots being arranged on opposite sides of the longitudinal, central or median axis (A) of the first part of the sole (1) and at a substantially identical distance from the corresponding adjacent lateral edge of the said first part of the sole (1).

10. Sole according to one or more of the previous claims, in which the said first part of the sole (1) is provided with four through slots (201), which are provided in pairs on opposite sides of the said median or central longitudinal axis (A ) of the first part of the sole (1), the slots (201) of each pair both substantially following the shape of the adjacent perimeter edge of the sole (1) and being substantially parallel to each other and each passing slot (201) being separated from the others of the opposite pair and / or of the same pair.

11. Sole according to one or more of the previous claims, wherein said at least two slots (201) or at least part or all of the slots (201) on one side of the central or median longitudinal axis (A) of the first part of the sole ( 1) connect with the corresponding slots (201) on the other side of the said central or median longitudinal axis (A) of the first part of the sole (1) with a section that follows the perimeter edge of the first part of the sole (1) along the front end and without interruptions of the buttonhole itself.

12. Sole according to one or more of the previous claims, wherein the recesses (202) in the thickness of the said second part of the sole (2) are distributed along one or more rows which extend along lines substantially parallel to the said grooves (102) in so as to form one or more rows of recesses (202) in the areas interposed between the said grooves (102) of the said second part of the sole (2).

13. Sole according to one or more of the previous claims, in which a so-called assembly insole is provided in combination, which is constituted by a rigid sheet-like element cut to size and with a shape corresponding to the plan shape of the entire sole (1, 2), the first part of the sole (1) being provided with a perimeter fin (901) which protrudes above the surface of the upper side of the sole, forming a perimeter containment frame and the said assembly insole (3) being of dimensions such as to be housed inside the said perimeter containment frame, while the said assembly insole (3) has in the plantar area substantially coinciding with the said second part of the sole (2) at least two or more through slots (103) which are substantially coinciding with at least some or all of the said grooves (102) and / or the said rows of recesses (202) provided adjacent to the said grooves (102) in the said second part of the sole (2), the said assembly insole having a hardness and / or an elastic modulus greater than the hardness and / or elastic modulus of said first part of the sole.

14. Sole according to one or more of the previous claims 1 to 12 in which an internal sole (4) is provided on which the foot rests which is made in the form of a material element having a lower hardness and / or a lower elastic modulus and / or a lower density than that of the first part of sole (1) and substantially similar or of the same size as those of the second part of the sole (2), which internal sole has a thickness greater than the protrusion of the said perimeter fin (901) which forms the containment frame of the said sole internal (4) and whose support surface of the foot is three-dimensionally shaped, corresponding to the anatomy of the foot itself, while on the side facing the upper side of the first and second parts of the sole (1, 2) in coupled condition , the said internal sole (4) has at least two or more longitudinal grooves (104), one or more of which or all of the said grooves (104) coincide respectively with one of the said grooves (102) provided in the second part of the sole (2 ) and which grooves (104) provided in the internal sole (4) have a substantially identical and congruent pattern to the corresponding groove (102) in said second part of the sole (2).

15. Sole according to claim 14, in which the said second part of the sole (2) has at least one further recess (502) for locking in position and relative anti-slip and / or for centering the said internal sole (4) with respect to the said second part of the sole (2), while the said internal sole (4) has a corresponding locking and centering rib (304) for each of the said recesses (502).

16. Sole according to claims 14 or 15, in which said internal sole (4) presents in its thickness a plurality of recesses (204) which on the side in contact with the combination of the first andsecond parts of the sole (1, 2 ) penetrate to a depth equal to part of the overall thickness of said internal sole (4) and which are distributed with a pre-established density and with a pre- established order along the extension of said internal sole (4).

17. Sole according to one or more of the previous claims wherein the material of the first part of the sole (1) is chosen with a hardness which is preferably between 30 and 70 A according to the SATRA TM205:2016 test performed at a temperature of 23° C±2°C and at a relative humidity of 50±10%, preferably from 50 to 60 A and a density of the material in relation to the volume displacement between 0.8g / cm3 and 1.0g / cm3, preferably between 0 .9 and 0.998g / cm3 according to the SATRA TM134: 1998 test performed at a temperature of 23°C±2°C and a relative humidity of 50±10%, while the material of the second part of the sole (2) and / or of the inner sole (4) is chosen with a hardness between 10 and 30 A, preferably between 15 and 21 A according to the SATRA TM205:2016 test performed at a temperature of 23°C±2°C and a relative humidity of 50±10% and / or with a material density in relation to the volume displacement between 0.6g / cm3 and 0.8g / cm3, preferably between 0.65 and 0.75g / cm3 according to the SATRA TM134: 1998 test performed at a temperature of 23°C±2°C and at a relative humidity of 50±10% and while the abrasion resistance value of the first part of the sole relative to the contact surface with the ground is between 100 and 200 mm3, preferably between 120 and 160 mm3, measured according to the DIN SATRA TM174:2016 test performed at a temperature of 23° C±2°C and at a relative humidity of 50±10% and the elastic resistance value of the complete sole i.e. the sole in the condition of a coupling of the said second part of the sole to the said first part of the sole is measured according to the Bata-PFOl test performed at a temperature of 23°C±2°C and at a relative humidity of 50±10%, and is between 8.0 and UN, preferably between 9.3 and 10.3N.

18. Footwear comprising an upper which is fixed to a sole made according to one or more of claims 1 to 17, said footwear being made according to one of the following two alternatives: an alternative in which the upper is shaped so as to cover a predominant part of the foot and the sole is made according to one or more of claims 1 to 13 and 17; an alternative in which the upper is shaped so as to leave a predominant part of the foot uncovered and / or is made up of thin bands or containment bands in the manner of a slipper or similar and the sole is made according to one or more of claims 1 to 12 and 14 to 17.

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