The present invention relates to the sector of footwear capable to adapt itself to shape or to deformations of the user's foot.
In the prior art, it is known in the footwear sector that purchasers of shoes often find it difficult to put them on due to problems that may be of various kinds, including:
These difficulties arise when the shoe can no longer expand horizontally, resulting in loss of user comfort.
It is well known that, unlike the length, which is a parameter that can be chosen when purchasing a shoe, the width of the shoe, and therefore of the sole on which it is mounted, is not an element that can be chosen.
In the state of the art, an attempt has been made to overcome the disadvantage of non-variability of width by creating:
Purpose of the present invention is to devise a sole for footwear capable of widening transversely to the development of the sole, maintaining this configuration after e relative foot is extracted from the footwear.
Another purpose of the present invention is to devise a sole for footwear the thickness of which has no manufacturing constraints such as those of the footwear of the prior art, thus making it a sole adaptable to any type of footwear.
A no less important purpose of the present invention is to devise a sole for footwear that is able to solve footwear problems arising from foot malformations (bunion, hammer toes etc.) much more effectively and at a much wider level than the footwear known in the state of the art.
The basic idea of the present invention is to provide at least the front portion of the sole of a shoe by means of two overlapping layers, of which a second layer, internal, intended to face a relative foot and a first layer, external, intended to face the ground. Each of the two layers has an approximately longitudinal cut. The first cut, relative to the first layer, is arranged proximal to a first lateral edge of the sole, while the second cut, relative to the second layer, is arranged proximal to a second lateral edge of the sole, opposite to the first.
In other words, the two cuts are mutually staggered.
Between the first and second layers a layer of double-sided adhesive is arranged, attached to the second layer and detached from the first layer by means of a folded film so that it can be extracted from the second cut.
The double-sided tape is arranged so that, when the film is removed, it sticks to both lips of the first cut, so as to prevent rapprochement between the lips. Thanks to the present invention, by inserting a foot inside the shoe equipped with the film, both the first and the second layer are free to expand transversely to the longitudinal development of the sole. While the foot is in the shoe, the extraction of the film causes the second layer to attach to the first by means of the double-sided tape, therefore, the lips of the second cut are no longer allowed to reciprocal rapprochement, so that the sole retains the acquired shape. Even the lips of the first cut remain dilated ensuring optimal comfort.
Preferably, the double-sided adhesive layer is made of waterproof material, so that the shoe can be put on even in case of rain without water penetrating inside.
According to another preferred embodiment of the invention, after the extraction of the film, the second cut is filled with a filling material, for example based on silicone, or polymer, sealing the sole of the shoe.
The dependent claims form an integral part of the present description.
Further characteristics and advantages of the invention will be clear from the description of a preferred but not exclusive sole for footwear able to adapt to the conformation and to malformations of the foot according to the present patent application, illustrated by way of non-limiting example in the appended drawings, wherein:
According to a preferred—but non-limiting—embodiment, the present invention relates to a sole (1) for footwear able to adapt to the conformation and to malformations of the foot, comprising:
Looking at
This shape, although rounded, recalls that of an isosceles trapezoid.
The first cut is made in order to facilitate the extraction of the protective film, while the second cut is made in order to facilitate the adaption of the sole to the shape of the foot.
In the figures it is seen that the two cuts are approximately parallel to the opposite lips of the isosceles trapezoid defined by the front portion of the sole. Nonetheless, the first cut can assume all intermediate angles and be perfectly aligned with the longitudinal direction of development X of the sole and arranged, for example, more centrally.
The second cut, although longitudinal in shape, can also be slightly curved to facilitate the adaptation of the half sole to the foot. Furthermore, it may be convenient to have the second cut in a more central position, while the first cut is closer to the edge of the sole.
What really matters is that the double-sided tape must be attached to the tread in order to fix the lips of the second cut to the tread when the protective film is removed.
Therefore, the double-sided adhesive layer overlaps the second cut and extends transversely to the longitudinal development direction X, towards the first cut, preferably up to its internal edge.
It is evident that it is considered as the internal lip of a cut, that lip that faces the other cut, while considering the external lip that faces towards the respective proximal edge of the sole.
It must also be clear that the half sole can also be a whole plant, i.e. a so-called insole, so as to cover the entire tread inside the shoe.
The cuts described above are through, i.e. for the entire thickness of the respective layers, i.e. the tread and the half sole.
These cuts can be angled with respect to the plane containing the sole, with an angle comprises between 45 and 90°.
With regard to the tread (2), the materials with which it can be made are those normally used in the state of the art, including:
The components of the sole (1) are preferably cut with a die or automatic cutting machine and, in the specific case of the tread (2), also making the first cut (4) for the insertion of the protective film (8) of the layer of double-sided tape (3). The shape of the cut (4) is conditioned by the design and aesthetics that will be given to the sole (1).
Alternatively to the materials listed above, the following can be used:
Such materials are generally used for molding.
Even with the aforementioned materials, the tread (2) is molded so as to carry the first cut (4).
The material for the realization of the half-sole (5) does not necessarily have to be the same as that of the tread (2).
In addition, the half-sole (5) does not necessarily have to be the same size as the tread (2), but may be larger or smaller as required.
The tread (2) can have a hollow part, in which the first cut (4) is made so as to provide for the insertion of the half plant (5) previously equipped with the second cut (6). Precisely for the construction methods of a cassette bottom, the dimensions of the half plant (5) are smaller and those of the tread (2).
Nonetheless, the shape of the half plant is similar, albeit smaller, than the shape of the front portion of the tread.
The half-sole (5) is made in the same way as the tread (2). Regardless of the material with which it is made, what must be kept unchanged is the type of cut (6) since it must be made “straight”, i.e. parallel to the longitudinal direction defined by the toe-heel connection line, in order to facilitate the opening of the same when the shoe is put on.
The double-sided adhesive layer (3) placed between the tread (2) and the half-sole (5) serves to secure said two parts at the moment in which the sole (1) has undergone the widening caused by the insertion of the foot into the shoe. In fact, when the footwear has adapted to the foot, ensuring perfect comfort, the double-sided adhesive layer (3) hitherto attached only to the tread (2) is freed from the relative protective film (8), also attaching to the half-sole (5), thereby obtaining the compaction of the sole (1).
The shape of the double-sided adhesive layer (3) is obtained by die-cutting or cutting and will be dictated, on one side, by the profile of the cut (4) on the tread (2); on the other it must exceed, according to a direction transverse to the longitudinal development direction X, by a few millimetres (about 4-6 mm), the second cut (6) of the half-sole (5) in order to block the position of the relative lips with respect to the tread. According to the longitudinal direction of development X, the double-sided tape must exceed the ends of the second cut (6) by 4-6 mm.
In other words, the double-sided adhesive layer extends between the first cut until it reaches and exceeds the second cut, when the half sole is attached to the tread in an operative configuration.
The double-sided adhesive layer thus made serves to ensure that, following the mutual removal of the lips of the second cut (6), it is able to constitute a barrier to the penetration of water into the sole.
To further improve the waterproofing of the tread, after removing the film, it is possible to inject in the first cut an adhesive paste capable of sealing the tread.
The material of the layer (3) is preferably a closed-cell, double-sided adhesive designed to ensure that it is waterproof, ensuring that the shoe is watertight and suitable for walking even on ground with pools of water or snow without these being able to penetrate inside.
As regards the protective film (8) of the double-sided adhesive layer (3), it is made of a die-cut silicone plastic film perforated to cover the face of the double sided layer in contact with the half sole and includes an extraction tab that extends for the transverse length of the double-sided layer crosses the tread and protrudes externally from it for 1-1.5 cm.
The film is attached to the double-sided adhesive starting from the edge of the same double-sided adhesive proximal to the first cut, folded on itself and inserted into the cut until it juts out from it.
The protective film (8) therefore has a transverse extension that is more than double compared to the double-sided adhesive layer (3). On one side, a flap of said protective film (8) is proximal to the cut (4) of the tread (2), while on the other side it must go 1-6 mm beyond the double-sided adhesive layer (3) so that, by pulling the extraction tongue on the tread (2), the protective film (8) unrolls, facilitating detachment from the double-sided adhesive layer (3). The protective film (8) is preferably made of siliconed plastic, in this way it is ensured that the adhesives that must be used in the assembly do not adhere to it, preventing its extraction.
The protective film (8) also facilitates the sliding between the half-sole (5) and the tread (2) and therefore their bonding during the phase of conformation of the sole to the foot, i.e. when the foot is inserted in the shoe and the protective film has not yet been extracted from it.
The upper is associated with the sole (1) to define the complete shoe, it can be shaped to wrap the foot right under the sole of the foot forming a tubular partially defined by an elastic layer (7) at least in correspondence with a portion that overlaps the second cut.
The purpose of the elastic layer (7) is to guarantee the enlargement of the upper when the shoe is put on, also ensuring that the upper itself adheres optimally to the foot.
The material of the elastic layer (7) is that normally available on the market and sold in elastic tapes.
It is important that:
A preferred method of assembling the sole (1) includes the following steps:
The second cut (6) of the half-sole (5) and the first cut (4) of the tread (2) may have different embodiments, including:
As can be seen in the figures, the cuts are essentially inside the contour of the tread and half sola respectively.
The length of the cuts (4, 6) is proportional to the conformability that is intended to be given to the sole (1); said length is variable depending on the material used to make said sole.
The sole (1) is presented to the operator who assembles the shoe like a normal pre-trimmed sole or with a template welt. The only precaution that the operator where to have is to avoid making the elastic layer (7) adhere to the half sole around the second cut.
The materials and dimensions of the invention as described above, illustrated in the appended drawings and claimed below, may be any as required. In addition, all the details are replaceable with others technically equivalent, while remaining within the sphere of protection of this patent application.
Number | Date | Country | Kind |
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102019000003549 | Mar 2019 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2020/052061 | 3/10/2020 | WO | 00 |