Within the technical sector of the invention it is known to obtain these shoes by joining together an upper and a sole with studs, each produced separately. According to the known art, this joint is obtained by means of stitching, gluing or riveting.

All these techniques, however, involve a considerable input in terms of labour which negatively affects the production costs thereof. Moreover, owing to the severe stresses to which this type of sports shoe is subject during sporting activities and the fact that it is used on uneven and/or muddy ground, it is not uncommon for the sole to become detached from the upper. This drawback occurs most frequently in sports shoes where the sole is joined to the upper by means of gluing.

In this technical sector it is also known that there exists the need to provide soles which are sufficiently rigid in order to ensure optimum gripping on the ground, but which at the same time are relatively soft and

flexible, both in order to adapt better to the irregularities of the ground and react more readily to the stresses induced by the athlete and in order to provide the shoe with an adequate degree of comfort.

For this purpose soles are known, comprising a relatively rigid structural portion on which the studs are fixed and a second portion made of relatively soft material and provided in regions of the sole which are not occupied by the studs and more subject to flexural stresses. Said soles are conventionally produced using the technique of co-moulding or over-moulding of the materials forming the aforementioned portions which are subsequently joined to the upper using one of the techniques mentioned above.

In this connection, shoes are also known where, in order to avoid damage to the athlete's joints, in particular the knee and ankle, the studs are displaceable to a certain degree with respect to the sole in response to sudden twisting stresses. In these shoes the studs are inserted in special open seats in the sole, inside which they may perform limited movements with respect to the sole in opposition to elastic means.

This solution, however, is limited by the fact that the capacity for displacement of the studs relative to the sole is often impaired owing to clogging of the seats with extraneous material such as mud or earth.

The problem underlying the following invention is that of providing a method for manufacture of a sports shoe of the type with studs and a shoe obtained using this method, which are structurally and functionally designed to overcome the above limitations described with reference to the known art mentioned.

Within the context of this problem a primary object of the invention is to provide a method which allows the manufacture of a sports shoe at a low cost and using a simplified operating procedure.

A second object of the invention is that of providing a sports shoe in which the sole is joined firmly to the upper.

A third object of the invention is that of enabling the manufacture of a shoe with studs which are displaceable to a limited degree with respect to the sole, separately or together, where the entry of extraneous material into the respective stud-receiving seats is prevented.

A fourth object of the invention is that of enabling the manufacture of soles in which regions with a high rigidity and regions which are more flexible may be combined with each other in a wide range of configurations which allow the structuring of the sole in a diversified manner according to the specific requirements associated with use of the shoe.

The characteristic features and advantages of the invention will emerge more clearly from the detailed description of some preferred examples of embodiment illustrated, by way of a non-limiting example, with reference to the accompanying drawings in which: - Figure 1 is a side elevation and partially sectioned view of a first example of a sports shoe manufactured using a method according to the present invention; - Figure 2 shows a bottom plan view of the shoe according to Figure 1; - Figure 3 shows a partial section along the line III- III of the shoe according to Figure 1; - Figure 4 shows a partial section along the line IV- IV of the shoe according to Figure 2; - Figure 5 is a partial bottom plan view of a second example of a shoe manufactured according to the method of the invention; - Figure 6 is a sectional view, along the line VI-VI, of a detail of the shoe according to Figure 5; - Figure 7 is a partial bottom plan view of a third example of a sports shoe manufactured according to the method of the invention; - Figure 8 is a sectional view, along the line VIII- VIII, of a detail of the shoe according to Figure 7; - Figure 9 is a partial bottom plan view of a fourth

example of a sports shoe manufactured according to the method of the invention; - Figure 10 is a cross-sectional view, along the line X-X, of a detail of the shoe according to Figure 9; - Figures 11 and 12 are corresponding views of a variation of embodiment of the shoe according to Figure 9 and the detail according to Figure 10, respectively.

With initial reference to Figures 1 to 4,1 denotes in its entirety a sports shoe of the type with studs, for example for use in the football sector, which is manufactured using a method in accordance with the present invention.

The shoe 1 comprises an upper 2, made of leather or synthetic material, a sole 3 joined to it along a perimetral zone thereof and an insole 3a arranged so as to close off the bottom of the shoe 1 and intended to receive the athlete's foot seated therein.

The insole 3a is preferably made of felt, of suitable thickness, and is fixed perimetrally to the edges of the upper 2 by means of stitching (for example classic or "strobe"type stitching) or another method conventional per se.

The sole 3 comprises a structural portion 4 which is relatively rigid and on which fixed studs 5 are provided and a second sole portion 6 made of material which is

softer and more flexible than the structural portion 4.

The structural portion 4 is made of plastic material, preferably polyurethane, and is obtained by means of moulding. For the manufacture thereof, depending on the specific requirements associated with use of the shoe, it is also envisaged using other materials-both polymer and non-polymer materials-such as polyamide and aramide resins or also metal, which may also be combined with each other.

In the preferred example of embodiment shown here, the studs 5 are formed as one piece with the structural portion 4 and each of them have a base portion 5a and a tip portion 5b projecting from the sole 3.

According to a main characteristic feature of the invention, the second sole portion 6 is made of a polyurethane-based expanded polymer material and is obtained by means of a reaction and injection moulding process known in the sector as"foaming"and thus indicated, for the sake of brevity, in the remainder of the description.

As shown more clearly in Figure 3, the structural portion 4 is nearly wholly enveloped by the second sole portion 6, except for the tip portions 5b of the studs 5.

Consequently, the second sole portion 6 is located between the structural portion 4 and the edges of the upper

2 to which it adheres so that they are firmly bonded together.

In this preferred example of embodiment of the invention, the second portion 6 is also located between the structural portion 4 and the insole 3a to which it likewise firmly adheres. A generally stronger connection, as well as a damping action between the studs 5 and the insole 3a, is thus obtained. If necessary, it is also possible to manufacture a shoe in which the insole 3a is in direct contact with the structural portion 4, the extension of the second portion 6 being limited to the perimetral zone of the sole 3, between the structural portion 4 and the upper 2 (Figures 10 and 12).

The structural portion 4 is also provided with through-openings and ribs which are denoted by 7 and 8, respectively. The through-openings 7 are passed through by the second portion 6, in this way achieving the dual effect of obtaining improved mutual fixing of the two sole portions 4 and 6 and increasing the flexibility of the sole 3 in the region of these through-openings. The ribs 8, in the same way as the studs 5, are partially enveloped in the second sole portion 6, in such a way that a tip portion 8a of the rib projects therefrom (see Figure 4). The ribs 8 are advantageously envisaged in zones of the sole 3 where there is considerable wear.

In order to satisfy particular technical requirements resulting from athletic movements, a variation of embodiment of the shoe 1, not shown in the accompanying drawings, is envisaged wherein the sole portions 4 and 6 extend laterally so as to embrace partially the sides of the upper 2, providing the shoe 1 with greater rigidity and a greater resistance to lateral forces.

The shoe 1 is manufactured using the process described below.

The upper 2 and the insole 3a are joined together by means of stitching or another technique known per se, so as to form an inner shoe, without a sole, which is arranged inside the mould together with the structural portion 4.

The shape of the mould and the arrangement therein of the structural portion 4 and the upper 2 joined to the insole 3a is such as to define, by means of the spaces left empty, the extension of the second sole portion 6. The latter is obtained by means of foaming, injecting into the mould, in a manner known per se, the basic components of a polyurethane mixture which, reacting, produces an expanded polymer material which fills the empty spaces of the mould.

The polyurethane mixture, during the foaming stage, is capable of adhering firmly to the materials forming the structural portion 4, the insole 3a and the upper 2. At the end of foaming, the second portion 6 is therefore

firmly fastened to the abovementioned elements.

It should be noted that, in this way, formation of the sole 3 and simultaneous joining of the latter to the upper 2 is advantageously obtained in a single operation.

With the process described above it is also possible to exploit advantageously the mechanical properties of the polyurethane-based polymer material used in the foaming process.

Owing to its mechanical strength, in particular abrasion resistance, said material may also be used in the regions of the sole 3 which are in direct contact with the ground. This allows the two portions 4 and 6 to be combined in a wide range of forms and configurations, depending on the requirements associated with use of the shoe 1. For example, it is possible to provide a sole 3 in which the second portion 6 is flush with the structural portion 4.

The elastic properties of the polymer material, in addition to providing the sole 3 with the flexibility already mentioned above, allow more effective and durable fastening of the second portion 6 to the structural portion 4, to the upper 2 and to the insole 3a also in severe conditions of use.

With reference to Figures 5 and 6,10 denotes overall a second example of a sports shoe manufactured according to

the method of the invention, in which similar elements are indicated using the same reference numbers as in the preceding example.

The shoe 10 differs from the shoe 1 described above in terms of the different form of the structural portion 4 and the provision, in the region of each stud 5, of respective damping elements 11 arranged between the structural portion 4 and the insole 3a and/or the upper 2.

A middle region 12 and lobes 13 extending therefrom so as to surround the studs 5 positioned along the perimetral zone of the sole 3 are defined on the structural portion 4.

Respective inset areas 14 therefore remain defined between the lobes 13, inside which areas the polymer material forming the second portion 6 is arranged during the foaming stage.

Any studs 15 provided in the middle region 12 of the structural portion 4 are correspondingly surrounded by a plurality of through-slits 16.

In this way, each zone of the sole 3 corresponding to a stud 5 or 15 is more independent in its flexing movements with respect to the adjacent zones, thus ensuring a more effective grip on the ground and a greater degree of adaptability to the irregularities thereof.

The damping elements 11, which are suitably made of resilient material, are coupled with each stud 5,15 by

means of insertion of a lug 17 inside a corresponding recess 18 formed in the structural portion 4 opposite each stud which therefore has a hollow cross-section.

The damping elements 11 are kept in the coupled condition by the bonding action of the polymer material of the second portion 6 which may be arranged coplanar with a base lla of the damping element 11, as in Figure 6, or may be arranged between said base and the insole 3a.

With reference to Figures 7 and 8, a third example of a shoe manufactured according to the method of the invention is indicated by 20. In this case also, details similar to those of the preceding example are distinguished by the same reference numbers.

The structural portion 4 of the shoe 20 comprises a first forefoot element 21a and a second heel element 21b distinct and separate from the first element 21a.

Moreover, both the elements 21a, 21b have, formed in them, through-openings 7 with a mainly longitudinal extension.

In this way, the flexibility of the sole 3 is accentuated, compared to the shoes 1,10 of the preceding examples, both in the transverse direction and in the longitudinal direction. The shoe 20 is also equipped with studs 22 which are inserted and engaged with play in seats 23 formed in both the elements 21a, 21b.

The studs 22 are therefore capable of limited

movements with respect to the sole 3 in opposition to elastic retaining means 24 located between the seats 23 and the studs 22.

It should be noted that the second portion 6, incorporating the elements 21a, 21, except for the tip portions 22b of the studs 22, firmly adheres to the respective base portions 22a thereof, sealing the seats 23 so as to prevent the entry therein of extraneous material (earth and/or mud) which could obstruct them.

Moreover, owing to the elastic property of the polymer material forming the second portion 6, the mobility of the studs 22 inside the respective seats 23 is not prevented.

With reference to Figures 9 to 12, a fourth example of a shoe manufactured according to the method of the invention-denoted overall by 30-is described, the details therein similar to those of the preceding examples being distinguished by the same reference numbers.

The shoe 30 differs from the shoe 20 of the preceding example in that the studs 22, instead of being mounted directly on the structural portion 4, are provided on a plate-shaped element 31 which is rotatably connected to the structural portion 4 by means of a pin 32. The plate- shaped element 31 is enveloped by the second portion 6 which likewise adheres to the base portion 22a of the studs. In this way it is possible to obtain, in the event

of lateral stresses, a partial oscillation of the plate- shaped element 31 and consequently the studs 22 connected thereto. In order to limit the extent of the aforementioned oscillating movement, one or two locating elements 33 integral with the structural portion 4 are also envisaged.

It should be noted that the particular form of the sole 3 ensures not only protection of the athlete's joints against torsional injuries in the event of severe and sudden twisting of the shoe, but also effective grip of the studs on the ground during torsional movements implicitly connected with the practice of the sports activity (for example golf or baseball) without affecting directly the joints.

Moreover, the plate-shaped elements 31 and the location of the pins 32 may be designed to satisfy different requirements in the various athletic movements associated with each specific sports discipline (Figures 9 and 11).

It is also envisaged that the studs 22 may be inclined to a limited degree with respect to the sole 3 in a mutually independent manner. For this purpose, the base portion 22a has a smaller frustoconical section around which an elastic element 34, for example of the O-ring type, is fixed. In this case, also, the elasticity of the

second portion 6 allows the displacement of the stud 22 both individually and at the same time as the other studs 22 connected to the same plate-shaped element 31.

Each stud 22 may be either of the fixed type (Figure 9) or the interchangeable type with a screw-type fastening 35 (Figure 12).

The present invention therefore solves the problem described above with reference to the cited known art, offering at the same time numerous other advantages, including a reduction in the time and costs associated with production of the sports shoes.

Further advantages consist in the firmness of the connection obtained between upper and sole and the possibility of combining the structural characteristics of the sole in a wide range of different configurations.