IMPROVED FOOTWEAR SOLE

Abstract

A footwear sole obtained by molding a single polymeric material, the footwear sole includes a lower surface to contact the ground, and an upper surface to support an insole and, on the upper surface, at least one elastically deformable cushioning element. The cushioning element includes an elongated element cantileverly protruding from the upper surface, and a plurality of tabs extending from the upper surface that are arranged around the elongated element, thereby defining a dome. In an undeformed configuration of the cushioning element the tabs are upright, and there is a gap between the tabs and the elongated element, and in a deformed configuration of the cushioning element the tabs are each bent towards the elongated element and in abutment against it. The switching from the undeformed to the deformed causes the area of the bearing surface provided to the insole by each cushioning element to gradually increase.

Claims

1. A footwear sole comprising a lower surface, intended to come into contact with the ground, and an upper surface, intended to support an insole and, on the upper surface, at least one elastically deformable cushioning element, wherein the at least one cushioning element comprises, in turn, an elongated element cantileverly protruding from the upper surface of the sole, and a plurality of tabs extending from the upper surface of the sole and that are arranged around the elongated element, and wherein in an undeformed configuration of the cushioning element the tabs are upright, and in a deformed configuration of the cushioning element the tabs are bent towards the elongated element and in abutment against it.

2. The footwear sole according to claim 1, wherein the tabs define a dome and the elongated element is central with respect to the tabs.

3. The footwear sole according to claim 1, wherein the elongated element has a circular cross-section, e.g. it is cylindrical or conical, or ellipsoidal.

4. The footwear sole according to claim 1, wherein the elongated element extends vertically, orthogonally to the upper surface of the sole, between the respective base and the respective top.

5. The footwear sole according to claim 1, wherein the top of the elongated element and the ends of the tabs distal with respect to the upper surface of the sole define a bearing surface, and wherein the area of the bearing surface in the deformed configuration of the cushioning element is greater than the area of the bearing surface in the undeformed configuration of the cushioning element.

6. The footwear sole according to claim 5, wherein the bearing surface is circular and the respective diameter in the undeformed configuration of the cushioning element is at least 4 mm, and is at least 5 mm in the deformed configuration of the cushioning element.

7. The footwear sole according to claim 1, wherein the tabs are separated from each other by a cutout, or slit, or slot, at the end distal with respect to the upper surface of the sole, and are joined at the base, near the upper surface of the sole.

8. The footwear sole according to claim 7, wherein the cutout between the tabs has one or more of the following features: its height extent is 3-8 mm; its width extent is 1.5-2.5 mm.

9. The footwear sole according to claim 1, wherein the tabs define a circular, truncated-cone or polygonal dome.

10. The footwear sole according to claim 1, wherein the elongated element is either cylindrical and the diameter of the respective cross-section is between 2.5 mm and 7 mm, or is truncated-cone shaped and its diameter at the base measures between 3.5 mm and 7 mm and its diameter at the top measures between 2.5 mm and 5 mm.

11. The footwear sole according to claim 1, wherein the cushioning element have one or more of the following features: height with respect to the upper surface of the sole between 3 mm and 30 mm; are, in cross-section, circumscribed by a circumference with diameter between 10 mm and 18 mm.

12. The footwear sole according to claim 1, wherein the thickness of the tabs is between 1.5 mm and 3 mm.

13. The footwear sole according to claim 1, wherein the elongated element acts as a stop element of the tabs during the switching to the deformed configuration of the cushioning element and the tabs slide on the side surface of the elongated element.

14. The footwear sole according to claim 1, wherein the tabs define a polygonal-section dome and are separated from each other by cutouts, or slits, vertical at the vertices of the polygonal section or at the sides of the polygonal section.

15. The footwear sole according to claim 1, comprising a plurality of cushioning elements arranged on the upper surface, and wherein the cushioning elements positioned at the wearer's heel are larger than the cushioning elements positioned at the middle zone of the wearer's foot.

16. The footwear sole according to claim 7, wherein the cutout between the tabs has one or more of the following features: a height extent is 4-6 mm; and a width extent is 1.5-2.5 mm.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0045] 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:

[0046] FIG. 1 is a perspective side view of a first embodiment of the sole according to the present invention;

[0047] FIG. 2 is an enlargement of a detail of FIG. 1, in particular a first cushioning element, in a first configuration;

[0048] FIG. 3 is a plan top view of a detail of FIG. 1, in particular a first cushioning element, in a second configuration;

[0049] FIG. 4 is a schematic, vertical section view of a detail of FIG. 1, in particular a first cushioning element;

[0050] FIG. 5 is a schematic, vertical section view of a detail of FIG. 1, in particular a part of a first cushioning element;

[0051] FIG. 6 is a plan top view of a second embodiment of the sole according to the present invention;

[0052] FIG. 7 is a schematic plan view of a second cushioning element;

[0053] FIG. 8 is a schematic plan view of a third cushioning element;

[0054] FIG. 9 is a perspective side view of a third embodiment of the sole according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0055] FIG. 1 is a perspective view of a sole 10 according to a first embodiment of the present invention, which comprises a front portion 1 intended to support the front portion of the foot of the wearer of the footwear made with the sole 10, and a back portion 2 at the hindfoot (heel) and midfoot zones of the wearer's foot. The lower surface 3 of the sole 10 is the one intended to come into contact with the ground during the walk; the opposite upper surface 4 is intended to support an insole, for example the insole of an upper assembly of the footwear.

[0056] In the example shown in FIG. 1, at the rear portion 2, on the upper surface 4, the sole 10 comprises a plurality of elastically deformable cushioning elements 11, whose function is to absorb the stresses given to the sole during the walk, and to dampen, i.e. to cushion, the stresses transmitted back to the wearer's foot, in order to make the walk comfortable.

[0057] The number and position of the cushioning elements are construction parameters on which the designer has a margin of choice: for example, the cushioning elements 11 can be positioned only on the front portion 1, only on the rear portion 2, or on both of them; the cushioning elements 11 can have an even deployment, i.e. a constant pitch (constant distance), and can be deployed in rows, or in an array.

[0058] It can be understood that in the soles 10 for children's footwear the number of cushioning elements 11 is lower than in the soles 10 for adult footwear; even the size may differ: smaller for children, larger for adults.

[0059] FIG. 2 is an enlargement of one of the cushioning elements 11 shown in FIG. 1. The cushioning elements 11 comprise an elongated element 12, which can also be defined protrusion, vertically extending from the upper surface 4 of sole 10, orthogonally thereto. In the figures, the elongated element 12 has a substantially cylindrical shape and therefore circular cross-section, although other geometric shapes, such as a truncated cone, are not excluded. The expression cross-section means the section considered on a plane parallel to the ground on which the sole rests, i.e. a plane parallel to the lower surface 3 of the sole 10, or a plane parallel to the upper surface 4. The elongated element 12 can also have, for example, a square, rectangular, or ellipsoidal cross-section.

[0060] The cushioning elements 11 further comprise a plurality of tabs 14 arranged around the elongated element 12 to define a kind of dome. The tabs 14 are separated by cutouts 13, which can also be defined as cutouts or slits. It should be noted that the dome-shaped elements described in relation to the known art are free of the cutouts 13, i.e. they have no tabs.

[0061] In the example shown in the figures, there are four tabs 14, likewise the cutouts 13, but in general the number of tabs 14, and therefore the number of cutouts 13, can be different, for example three, five, six, etc.

[0062] The tabs 14 substantially extend in the vertical direction and are elastic, i.e. they are susceptible to elastically flex in the direction of the elongated element 12, and vice versa. The elongated element 12 is also elastic, and for this reason it is deformable in compression, as will be explained below.

[0063] Preferably, as shown in the example of FIG. 2, the tabs 14 define a circular dome.

[0064] In the undeformed configuration of the cushioning elements 11, i.e. in the resting condition shown in FIG. 2 and corresponding to the absence of weight applied by the wearer to the sole 10, the tabs 14 are upright and there is a gap 15 between the tabs and the elongated element 12. The curvature of the tabs 14 visible in FIG. 2 is the normal curvature at rest: the tabs define a dome zo around the elongated element 12. The free ends of the tabs 14 and the top of the elongated element 12 define a bearing surface of the insole of the footwear. It is precisely on this bearing surface that the weight of the footwear wearer is transferred.

[0065] During the walk, the wearer of the shoe loads the sole 10 with his own weight, i.e. exerts pressure on the sole 10, towards the ground. FIG. 3 is a top view of a cushioning element 11 in a deformed configuration. As it can be noted, the tabs 14—subjected to the pressure given by the wearer—have deformed, flexing and converging on the elongated element 12, which acts as stop element. The gap 15 initially present between the free ends of the tabs 14 and the elongated element 12 has been eliminated and the ends of the tabs have been brought in abutment against the side surface 12′ of the elongated element. In this condition, the tabs 14 can return to the undeformed configuration shown in FIG. 2, if the stress that caused their bending is no more present, or they can continue to flex on themselves, if the stress increases, and in the latter case the ends of the tabs 14 slide on the side surface 12′ of the elongated element 12.

[0066] Still referring to FIG. 3, the circumference S1 depicted by dashed line circumscribes the bearing surface in the undeformed configuration of the cushioning element 11. Preferably, the diameter of the bearing surface in the undeformed configuration is at least 4 mm. In the deformed configuration of the cushioning element 11, the circumference S2 depicted by dashed line circumscribes the bearing surface. Preferably, the diameter of the bearing surface in the deformed configuration is at least 5 mm.

[0067] In other words, when the weight of the footwear wearer is applied to the sole 10, the tabs 14 are pushed downwards, i.e. towards the upper surface 4 of the sole 10 itself and this causes the tabs 14 to flex towards the elongated element 12. The tabs 14 converge on the elongated element 12 and the bearing surface increases: the area circumscribed by the circumference S2 is greater than the area circumscribed by the circumference 51.

[0068] The advantage of this solution has been described above: the load damping, and therefore the reaction provided by the sole 10, are progressive and the comfort felt by the wearer is considerable.

[0069] FIG. 4 is a schematic view of a cushioning element 11 in vertical section, i.e. in a vertical plane orthogonal to the lower surface 3 of the sole 10. The cushioning element 11 is depicted by dashed lines in the undeformed configuration, and by continuous lines in the deformed configuration. As can be seen, the elastic deformation affects both the elongated element 12, which works by compression, and the tabs 14, which work by flexing. During the deformation, the elongated element is compressed and widens, i.e. it laterally warps, and the tabs 14 bend on themselves and the respective ends rest against the side surface 12′ of the elongated element and slide thereon while further flexing as indicated by the arrows.

[0070] In the example shown in FIGS. 1-5, the elongated element 12 is cylindrical and the diameter of the respective cross-section is between 2.5 mm and 7 mm; as an alternative, the elongated element 12 can be truncated-cone shaped, for example having a diameter at the base between 3.5 mm and 7 mm and a diameter at the top between 2.5 mm and 5 mm.

[0071] In the example shown in FIGS. 1-5, the width L of the cutout 13 between the tabs 14 is equal to 1.5-2.5 mm.

[0072] The numeral reference 14′ in FIG. 2 denotes the base of the cushioning elements 11. More in particular, as it can be seen, the cutouts 13 do not separate the tabs 14′ up to the respective base; the tabs 14 are joined at the same shared base 14′. This solution is for giving greater wear resistance to the tabs 14, i.e. greater strength.

[0073] FIG. 5 is a vertical section view of a tab 14 extending from the base 14′ shared with the other tabs 14 and a free end 14″ distal with respect to the upper surface 4 of the sole 10. The height H of the cutout 13 that separates the tab 14 from another tab 14 is 3-8 mm, for example 4-6 mm. In general, as the height H increases, so does the deformability of the tabs 14, and thus the absorption of impacts and loads by the sole 10 improves. It is preferable, however, that the height H of the cutout 13 does not extend starting from the upper surface 4 of the sole 10, otherwise the sole 10 may become too cushioning thereby risking that a feeling of poor stability is transmitted to the wearer.

[0074] Advantageously, within the same sole 10, regions with different values of H can be identified, depending on different needs: for example, at the heel 2 is preferable to have a higher level of cushioning and therefore a value of H greater than for example the middle zone of the foot at the plantar arch.

[0075] Preferably, as shown in FIG. 5, the thickness S of the tabs 14 is between 1.5 mm and 2.5 mm.

[0076] Preferably the height of elongated element 12, and in general of the cushioning elements 11, with respect to the upper surface of the sole is between 3 mm (the elements closest to the front portion 1 of the sole 10) and 30 mm (the elements furthest from the front portion 1).

[0077] Preferably, each circular cushioning element 11 has an outer diameter (cross-section) between 10 mm and 18 mm.

[0078] Preferably the elongated element 12 and the tabs 14 have the same height, so that as the tabs 14 bend they cannot pass over the elongated element.

[0079] FIG. 6 is a plan top view of a second embodiment 10′ of the sole, wherein the cushioning elements 11′ are positioned on the front portion 1 and are not circular, but have an ellipsoidal shape; the elongated elements 21 have a substantially rectangular or ellipsoidal section, and four tabs 20 extend around a single elongated element 21.

[0080] The ellipsoidal shape is preferable when one or more cushioning elements 11′ are to be placed in the front portion 1 of the sole 10′, the one of the forefoot, thereby combining the cushioning effect with improved flexibility: in this case, the cushioning elements 11′ advantageously have a plurality of cutouts 13 having at least some of them, depicted by 13′, aligned with the flexing direction f of the sole 10′.

[0081] FIGS. 7 and 8 show alternative embodiments 11″ and 11′″ of the cushioning elements 11, in which the tabs 14 define a polygonal shape, in particular a pentagon, and the elongated element 12 is cylindrical. A polygonal shape, like the pentagon, can be achieved as in FIG. 8 with the cutouts 13′″ at the vertices of the polygon, or as in FIG. 7, with the cutouts 13″ at an intermediate position between two vertices, for example halfway between two vertices of the polygon. The configuration with the cutouts 13″″ at the vertices of the polygon is the least rigid of the two, as the vertices have greater deformation resistance. The configuration with the cutouts 13″ at any position between two vertices is advantageous if the hardness of the material constituting the sole 10, 10′ cannot be increased, or if the height extension of the cushioning elements 11 would require the walls to be made thicker thus causing an increase in the total weight of the sole and a greater waste of material.

[0082] FIG. 9 shows a sole 10″ according to the present invention, equipped with a single large cushioning element 11 positioned on the rear portion.

[0083] Advantageously, the sole 10, 10′ can be made by molding, using for example rubber, EVA (ethylene vinyl acetate), PU (polyurethane) or TR (thermoplastic rubber); the cushioning elements 11, 11′, 11″, 11″′ are obtained with the sole as well, in the same molding step.