WO2012110978A1

WO2012110978A1 - An expandable shoe sole

Info

Publication number: WO2012110978A1
Application number: PCT/IB2012/050713
Authority: WO
Inventors: Eugenia GHERA
Original assignee: Ghera Eugenia
Priority date: 2011-02-18
Filing date: 2012-02-16
Publication date: 2012-08-23
Also published as: ITFI20110031A1; EP2699120A1; IT1404133B1

Abstract

A shoe sole characterized by the fact that it comprises at least one elastically yielding portion ( 2 ), so that the outsole is adapted to expand during use under the wearer's weight.

Description

TITLE

AN EXPANDABLE SHOE SOLE

DESCRIPTION

Technical field of the invention

The present invention concerns the footwear field and, in particular, it regards a shoe sole having novel characteristics.

Background of the invention

It is well known that the greatest wearing comfort is and has always been one of the main targets of research in the footwear field. One of the most common problems is given by the fact that feet tend to swell during use, so that a shoe size that is appropriate at rest becomes tight and therefore uncomfortable with use, especially when long lasting. On the other hand, the choice of a shoe with a too large size, in anticipation of the foot's physiological behavior, cannot be a satisfactory solution, making it uncomfortable to wear those shoes during most of every-day use situations.

More generally speaking, a shoe/size appearing comfortable and fit when worn at rest, by way of example while trying and choosing the shoes in a shop, turns out to no longer be as comfortable in dynamic situations, e.g. with the movement of the feet, thus disappointing the user and even making the shoe useless.

Summary of the invention

The present invention aims at tackling and solving this problem, providing a shoe sole structure allowing to create a shoe with the highest comfort in all use situations.

According to the present invention, this and other objects are attained by a shoe sole characterized by the fact that it comprises at least one elastically yielding portion, so that the sole is adapted to expand during use under the user's weight.

In this way, if the shoe can have a given size chosen as fit at rest, it will turn out to be more comfortable when used in walking, following the foot's physiology. On the contrary, when returning at rest (seated user), the sole will recover its undeformed configuration, corresponding to a smaller size.

The above mentioned portion can simply comprise at least one crosswise band made of an elastically yielding material, adapted to expand under the user's weight by extending in a metatarsal area of the foot. Advantageously, however, such portions are given by inserts made of the elastically yielding material and arranged on the upper face of an outsole. Such inserts can preferably comprise a plurality of elongated inserts, placed at least in a tarsal area, radially or parallel in a longitudinal direction. To assist the expansion, the sole advantageously provides for a number of cuts which open under the user's weight, formed in the same outsole or preferably on a insole which is associated to the outsole to form the sole structure. In this case, the cuts can be placed in such a way as to correspond to respective inserts arranged on the outsole.

The elastically yielding material can for example and typically be low-density natural or synthetic rubber (such as polyurethane foam) or silicone gel.

Brief description of the drawings

The characteristics and advantages of the outsole according to the present invention will be apparent from the following description of an embodiment thereof, given as a non-limiting example with reference to the attached drawings, wherein:

-figure 1 is a schematic top plan view of a sole representing the general concept which underlies the invention;

-figure 2 is, again schematically, an exploded perspective view of a portion of shoe including a sole structure according to a preferred embodiment of the invention;

-figures 3 and 4 are cross section views of the outsole of figure 2, respectively taken according to plans Ill-Ill and IV-IV of said figure.

Detailed description of the invention

With reference for the moment to figure 1 only, a sole according to the present invention provides for a modeled outsole body 1 with traditional profile and overall shape. The body 1 is made of a conventional flexible material, which is however substantially non-elastic, at least at a level of macroscopic deformations, therefore not taking into consideration the small adjustments in response to the contact and friction stresses which occur during the normal use of the shoe. Such a material can by way of example be a high-density polyurethane resin commonly used in the footwear field. It is a substantially non-yielding material; the sole can in any case be associated to a soft footbed or arch support to superimpose upon the sole itself.

The body 1 is elongated according to a longitudinal axis X, corresponding to the longitudinal axis of the foot. According to a first and more generic embodiment of the present invention, the continuous development of the body 1 is interrupted, by way of example, by at least one crosswise band 2 made of an elastically yielding material, such as low-density polyurethane resin or silicone gel, both being materials already known and used - like other equivalent ones - for cushioning purposes in the footwear field. The band 2 completely crosses the body 1 , substantially in the position of the metatarsal area, and warps so as to expand the surface area of the body 1 and, consequently, of the outsole, with the pressure applied by the foot while walking.

Advantageously, this reversible expansibility of the outsole is obtained also with the contribution of a plurality of cuts 3, preferably formed in a substantially radial way in the tarsal area, adapted to open because of the pressure of the foot, so to assist the expansion of the outsole, in this case also towards the rear part. Always according to a possible embodiment, the radial cuts (pointing a center in the finger area) are already partially open in the configuration at rest and can also contain portions 4 of the same soft material which the band 2 is made of. The cuts can also be present in the heel area and have a different shape with respect to the almond shape shown as a mere example. Linear or "V" cuts (with the midpoint of the "V" in the finger area) can for example be obtained. Other shapes/configurations can be adopted according to the specific needs.

As indicated by the dotted profile 5, a shoe sole structure according to the present invention will provide for an appropriate perimetrical welt 6, which is enlarged or extensible to allow and assist the expansion of the outsole. The shoe, e.g. in particular the insole and/or its connection to the vamp, shall then provide for other constructions able in their turn to enhance, assist or at least not to hinder the expansion of the outsole and reduce the stress on the forefoot, thus contributing to the creation of a shoe capable of "automatically" increasing its width during use of an amount of about one shoe size unit (standard units) or half shoe size unit, to adapt to the foot's physiology and to increase the comfort of use without diminishing functionality.

It is in connection with these particular constructions that the description of a particularly preferred embodiment for a practical reduction to use of the invention is given herebelow with reference to figures from 2 to 4. According to such embodiment the portions made of elastically yielding material consist of inserts 12a and 12b, integrated in the outsole 1 1 an in particular housed in suitable cavities 1 1 c formed in a top face 1 1 a of the outsole itself, in this case an outsole with a concave top face and an upwards projecting peripheral rim.

Such inserts advantageously provide for a distribution of tarsal inserts 12a, each of which with an elongated shape in the longitudinal direction of the outsole, by way of example three substantially parallel inserts extending between an area next to the point of the outsole and an area at approximately one third of the longitudinal development of the outsole itself, measured as of the mentioned point. A disc-shaped insert 12b can then be advantageously provided in the heel area, with a diameter such to occupy a substantial part of the same, for example between 3 and 5 cm.

Preferably, in correspondence to each cavity 1 1 c housing an insert 12a and 12b, the outsole forms, on the opposite side 1 1 b, e.g. the tread surface, a slight projection 20 with respect to the general plane of the tread surface itself. Furthermore, the contour of such projection is defined by a carving 21 which penetrates the tread surface. Such a configuration, along with the thinning of the hard material of the outsole because of the insert-housing cavity, grants to that given portion of outsole the ability to assist the expansion of the insert, thus ensuring the expandability performance which underlies the present invention with a solution guaranteeing comfort, a simple construction and also a high aesthetic value.

This embodiment advantageously provides for cuts 13 which are not formed in the outsole but in an insole portion 17 which, according to the common techniques of footwear production, completes the sole structure. Such cuts can as in the example only concern the tarsal area in correspondence with the elongated tarsal inserts 12a (the soft yielding material of which accommodates and assists the opening of the cut and a certain penetration of its edges into the inserts themselves) with a linear and longitudinal development in two or more rows, or can also be formed in other areas. In any case the cuts, by opening under the wearer's weight, ease and comply with the expansion of the outsole and optimize the adaptation and the personalization of the shoe size itself, thus making the shoe comfortable to wear for any kind of user. Advantageously, to further increase such effect, the insole portion 17 shall provide for an elastic perimetrical connection to the vamp 18, by way of example through a stitching 19 made of an elastic fiber. Again, this is a further prerogative of flexibility which is granted according to the present invention to make the shoe elastically adjustable to the user's foot also as the circumstances of use change (a more or less tired and, consequently, swollen foot). The assembly between the insole/vamp and the outsole can then be made according to traditional techniques, for example by gluing, obviously taking care to allow for the opening of the cuts 13 and the extension of the stitching 19.

The present invention therefore provides for a novel solution capable of offering a surprising increase in the wearing quality of a shoe, allowing the user to avoid those typical inconveniences due to a long lasting wearing and get a wearing sensation which is and keeps closer to that of a customized shoe also in different use situations.

The present invention has been here described with reference to its preferred embodiment. It should be understood that that there may be other embodiments within the same inventive concept, as defined by the scope of protection of the following claims.

Claims

1. A shoe sole structure comprising an outsole characterized by the fact that said outsole comprises at least one elastically yielding portion (2) so that the outsole is adapted to expand during use under the user's weight.

2. The sole structure according to claim 1 , wherein said outsole comprises a body (1 ) made of a substantially non-yielding and/or non-elastic material, and at least one insert (2) made of a soft elastically yielding material, adapted to expand under the user's weight.

3. The sole structure according to claim 2, wherein said at least one insert comprises a band made of the elastically yielding material (2) which extends crosswise in such body (1 ).

4. The sole structure according to claim 3, comprising a plurality of cuts adapted to open under the user's weight and formed in said outsole at least in a tarsal region.

5. The sole structure according to claim 4, wherein said cuts (3) are already partially open in a configuration at rest of the outsole.

6. The sole structure according to claim 4 or 5, wherein said cuts (3) house portions (4) of said elastically yielding material.

7. The sole structure according to any of the claims from 4 to 6, wherein said cuts (3) extend radially pointing a center substantially in the finger area.

8. The sole structure according to claim 2, wherein said at least one insert comprises a plurality of elongated inserts (12a) housed in respective cavities formed in a top face of said outsole and extending in a longitudinal direction in a tarsal area of said body.

9. The sole structure according to claim 8, wherein said elongated inserts (12a) comprise three substantially parallel inserts.

10. The sole structure according to claim 8 or 9, wherein said elongated inserts (12a) extend between an area next to the point of the outsole and an area at approximately one third of the longitudinal development of the outsole itself.

1 1. The sole structure according to any of the claims from 8 to 10, further comprising a substantially disc-shaped insert (12b) housed in a cavity formed in said top face of said outsole in a heel area.

12. The sole structure according to any of the claims from 8 to 1 1 , wherein in correspondence to each cavity housing a respective insert (12a, 12b), the outsole forms on its tread surface, opposite to said top face, a projection (21 ) with respect to the general plane of such surface, the contour of such projection (20) being defined by a carving (21 ) penetrating said surface.

13. The sole structure according to claim 12, wherein in correspondence to each insert-housing cavity, the material of said outsole is made thinner.

14. The sole structure according to any of the claims from 8 to 13, comprising an insole (17) superimposed upon said outsole, where cuts (13) adapted to open under the user's weight are formed.

15. The sole structure according to claim 14, wherein said cuts are formed in the tarsal area in correspondence to said elongated tarsal inserts (12a), with a linear and longitudinal development in two or more rows.

16. The sole structure according to claim 14 or 15, wherein said insole (17) provides for a perimetrical elastic connection to a shoe vamp, e.g. through a stitching (19) made of an elastic fiber.

17. The outsole according to any of the previous claims, wherein said elastically yielding material is natural rubber or low-density synthetic resin or silicone gel.