Field of the invention

The present invention relates to an item of footwear of adjustable size.

In particular, the present invention proposes an item of footwear designed preferably for infants in their first months of life, during which the feet of the infant grow by many sizes in a short period of time.

State of the art

It is known that there exist shoes of adjustable length, in which the sole is divided into mutually mobile parts to adapt the length of the shoe to the desired size.

To these soles uppers are then applied, which are also adjustable.

Adjustable footwear of a known type presents, however, a wide range of drawbacks as regards the quality of resting afforded for the foot, a feature that is of particular importance in the case of shoes for infants. A second drawback is represented by the relative rigidity of the adjustment, which is generally obtained by connecting with slotted fittings the mobile parts according to a certain number of pre-set positions corresponding to the desired sizes.

Summary of the invention A first purpose of the invention is consequently to propose an adjustable item of footwear that will enable an exact adjustment, to size, of the item of footwear with a correct proportionality of the adjustment in the longitudinal and transverse dimensions of the foot.

List of the drawings Further characteristics and advantages of the present invention will emerge more clearly from the indicative, and consequently non-limiting, description of a preferred, though non-exclusive, embodiment of the invention, as illustrated in the annexed plates of drawings, in which: - Figure 1 shows an item of footwear according to the invention;

- Figure 2 shows a toe portion of the upper of the item of footwear of Figure

1 ;

- Figure 3 shows the sole of the item of footwear of Figure 1 in plan view; - Figure 4 is a median longitudinal section of the item of footwear;

- Figure 5 shows a leather innersole of the item of footwear according to the invention, connected to an adjustment mechanism;

- Figures 6 and 7 show a first elastic innersole and a second elastic innersole of the item of footwear; - Figure 8 shows a sole according to the invention suitable for housing a stimulator device;

- Figures 9 and 10 show respectively a neural electrostimulator and an electrostimulating gel that can be used with the sole of Figure 3;

- Figure 11 shows a preferred embodiment of an innersole according to the invention; and

- Figure 12 and 13 show, respectively, a perspective view and a view in partial cross section of a preferred embodiment of an adjustment mechanism according to the invention.

Detailed description With reference to the attached figures, an item of footwear 1 according to the invention comprises a unitary sole 5 applied on which is a unitary upper 2, i.e., one made up of a number of parts stably stitched together. All around the sole 5, in contact with the upper 2, a guard 4 is provided, preferably made of elastically deformable material so as to accompany the displacements of the upper 2 remaining in contact therewith.

According to the present invention, the sole 5 comprises an area 32 of sliding for the innersole 13 interrupted by lightening grooves 30 and provided with a projection 21 in the form of a wedge facing the heel, which is engaged and is able to slide with respect to the cavity 22 made in the leather innersole 13. The item of footwear further comprises a first innersole made of elastic material 6, fixed to the front portion 17 of the upper 2 along a line of stitching 18 set at a distance from the fixing edge 7 of the upper to the sole of a pre-set size in order to define a free band such as to enable an elastic deformation of the innersole 6.

The innersole 6 is moreover provided with a wedge-shaped cavity 30, capable of housing the projection 21 of the sole 5. Provided on top of the first elastic innersole 6 is a leather innersole 13, which in the front part has a longitudinal separation cut 23 that terminates in a cavity 22 shaped like a wedge facing the heel of the item of footwear, which has dimensions corresponding to the projection 21 of the sole 5. Provided on top of the leather innersole 13 is then a second elastic innersole 20, which is stitched laterally to the upper, along a line of stitching 19 on top of the line of stitching 18 of the first innersole in such a way that the rigid leather innersole 13 will be enclosed as if in a bag between the two elastic innersoles 6, 20.

With reference in particular to Figure 4, there follows a description of a possible mechanism for adjustment of the length of the item of footwear 1 and of the relative arrangement of the various components .

The mechanism comprises a first plate 8 fixed with respect to the rear area of the sole 5 and provided at the bottom with one or more seats 11 through which an adjustment screw 10 can be passed and turned. Preferably, the mechanism is housed inside a cavity 27 made in the heel part of the unitary sole 5.

The mechanism then comprises a second plate 9, which is able to slide with respect to the sole 5, is also provided in the bottom part with a threaded seat or bushing 12 in which the screw 10 can engage, and is fixed with screws or other means 29 to the leather innersole 13.

The screw 10 is housed inside the sole 5 and can turn freely in a seat, which is made in the sole itself and which communicates with the rear area of the heel 16 so as to be adjustable from outside for example using a screwdriver or similar means, such as Allen wrenches and the like.

In operation, the screw 10 can, hence, be turned to displace the plate 9 in a continuous way, through engagement with the bushing 12. With the displacement of the plate 9, the innersole 13 fixed with respect to the second plate 9 advances, and the wedge 21 of the sole 5 forces divarication of the cavity 22 of the innersole 13, which at the same time advances and widens, pushing on the front part and front side part of the upper 2. In this way, the upper 2 has the possibility of assuming precisely all the intermediate positions between the minimum size and the maximum size envisaged (typically between sizes 23 and 25 Paris points for footwear designed for infants), and this both in a longitudinal direction and in width.

Once the right size has been found, the item of footwear 1 is fixed to the foot of the user by means of adjustable closing mechanisms widely known, such as, for example, the use of an adjustable lace that passes through eyelets or else the use of a Velcro ® strap, both of which are in any case provided directly on the upper 2.

Advantageously, the item of footwear according to the invention enables adaptation of the item of footwear to the foot in an exact way, whilst the item of footwear does not modify substantially its outer appearance, thanks to the fact that the mechanism is completely internal to the sole, and thanks to the deformability of the guard, which adapts to the displacements of the upper.

With reference to Figures 8-10, according to a further aspect of the invention, a sole 5 for footwear can be provided with a seat 26 for housing a stimulation device, which has the task of issuing electromagnetic waves at a frequency in a range of approximately 16-20 MHz with the effect of causing in the nervous system of the user a mechanism of spontaneous correction of the posture. Preferably, the stimulation device may be a neural electrostimulator 37 of the type comprising a programmable microprocessor or chip, supplied by a battery and capable of emitting electromagnetic waves in the aforementioned frequency range. It is moreover possible to use an electrostimulating element 28 of the gel type, also this supplied by a battery.

Advantageously, it has been found that in both cases, if the seat 26 and the device 37/28 have an arch shape or an approximately "bean" shape, a better nervous stimulation of the foot and a better corrective effect is obtained.

With reference to Figure 11 a preferred embodiment of the rigid innersole 13 is described, in which the wedge-shaped slot 22 proceeds with a cut 33 facing the heel, and moreover provided is a U-shaped notch approximately parallel to the lateral and front profile of the innersole, in which the rigid material of the innersole 13 is replaced by a strip 34 of elastic material.

With this solution, the control of the transverse expansion of the innersole 13 and its return in the case of recession of the plate 9 fixed thereto is improved. With reference to Figure 12, a preferred embodiment of the mechanism of advance of the innersole 13 is described, comprising a box-like covering body 35 provided with the seats 11 for rotation of the screw 10 and in which the plate 9 can slide in a guided way.

Advantageously, the covering 35 is a body in itself suited for being located in the area of the heel 16 and is provided with an opening 36 for the passage of the tool for adjustment of the screw 10. Once again with reference to Figure 12, a cylindrical bushing 37 is shown, which in use is inserted in a corresponding hole 38 of the heel 16 and can be opened/closed by a plug 39 (in the example of Figure 12 a star-shaped plug) The invention thus conceived is evidently suited to industrial application; it may likewise undergo numerous modifications and variations, all of which fall within the scope of the inventive idea; all the items may moreover be replaced by technically equivalent elements.