TECHNICAL FIELD

The present invention relates to a method and to- a device for manufacturing shoes with a heel. BACKGROUND ART

In general, the manufacture of shoes with a heel, in particular ladies' shoes, comprises a processing phase, during which glue is applied to an upper surface of the heel which is then coupled to a relative upper. In order to achieve the correct stabilization of the glue, the upper and the heel are normally held together in a position one on top of the other by means of screws or nails, or simply by means of a form, to which the heel and the upper are coupled until the glue hardens.

In any case, in order to couple the upper to the heel the heel must be maintained in a fixed position by means of a clamp.

To avoid damaging the heel, in the prior art solutions at least one of the jaws of the clamp is shaped so as to allow said jaw to adhere completely and perfectly to the part of the heel engaged thereby. This result is normally achieved by manufacturing a half-impression of the heel and fitting said half-impression, normally made of a rigid plastic material, to said jaw.

Said half-impression is normally a non-dedicated half- impression, which has, in use, limited points of contact with the heel that must be fixed in a mechanically adjustable manner, with the consequence that the clamping pressure is concentrated in a limited number of points causing deformation and, at times, damaging the heel.

In any case, according to the prior art, coupling an upper to a relative heel involves, for each type of shoe with a heel to be manufactured, the production of at least one half-impression, which is generally not dedicated, of at least the relative heel and the assembly of said half- impression on the relative jaw of the clamp.

From the above description it is clear that, in order to manufacture a series of different types of shoes with different types of heels, at least one half-impression must be produced for each type of heel and/or shoe and said half-impression must be replaced each time the type of shoe is changed.

This prior art method has several drawbacks both in terms of expense, given the costs of manufacturing and storing the different half-impressions, and of a technical nature, since the operations to replace the half- impressions result in relatively long down times.

DISCLOSURE OF INVENTION

The purpose of the present invention is to provide a method and a device for manufacturing shoes with a heel, which overcome the drawbacks described above. According to the present invention there is provided a method for manufacturing shoes with a heel according to that claimed in claim 1 and, preferably, in any one of the subsequent claims depending directly or indirectly on claim 1.

According to the present invention there is also provided a device according to that claimed in claim 4 and, preferably, in any one of the subsequent claims depending directly or indirectly on claim 4. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, illustrating a non- limiting embodiment thereof, in which:

- figures 1 and 2 are, respectively, a side and a plan elevation view of a detail of a preferred embodiment of the device according to the present invention in a first operating configuration;

- figures 3 and 4 are similar to figures 1 and 2 and illustrate the detail of figures 1 and 2 in respective different operating configurations; and

- figures 5, 6 and 7 are cross-sections along the line ^' V-V, VI-VI and, respectively, VII-VII of figure 4;

- figure 8 is a partially exploded front view of the detail of figure 1; and - figures 9, 10 and 11 are similar to figure 1 and illustrate the detail of figure 1 in three successive steps of manufacturing a shoe with a, heel .

BEST MODE FOR CARRYING OUT THE INVENTION With reference to figure 1, designated as a whole by number 1 is a device for manufacturing shoes 2 (figure 11) , in particular ladies' shoes, comprising an upper 3 and a rear heel 4.

The device 1 comprises a clamping member 5 suitable to lock the heel 4 in a predetermined position during the coupling of said heel 4 to the upper 3. The clamping member 5 comprises two jaws, indicated respectively by numbers 6 and 7 , which are movable with respect to one another from and to a closed position (figures 3, 9 and 10), in which the jaws 6 and 7 lock the heel 4 between them. According to that illustrated more clearly in figures 5 to 7 , the jaw 6 comprises a support body 8, having an arched cross-section limited, on the side facing the jaw 7, by a substantially semi-cylindrical concave surface 9, which has an axis 10, extends for the entire length of said support body 8 and delimits a cavity, inside which there is housed a pad 11.

The pad 11 has a lining 11a, which is integral with the support body 8, is normally made of a flexible elastic material, preferably a silicone material, and contains ferromagnetic particulate material 12, normally filings or iron spheres . The jaw 7, on the other hand, comprises a ^' support body 13, which is ^■ defined, in the example that is illustrated, by a flat plate, which is arranged in a substantially transversal position with respect to the axis 10, is arranged on a slope with respect to the axis 10 and is limited, on the side facing the jaw 6, by a substantially semi-cylindrical concave surface 14, which has an axis 15 that is transversal with respect to the axis

10 and delimits a cavity inside which there is partially housed a pad 16.

The pad 16 has a lining 16a, which is substantially cylindrical in shape coaxial to the axis 15, is normally made of a flexible elastic material, preferably a silicone material,' and also contains ferromagnetic particulate material 12, normally filings or iron spheres.

The jaws 6 and 7 are movable from and to a closed position by means of actuating devices (not illustrated) of a type that is known, and the pads 11 and 16 are coupled to a generator 18 of a known type suitable to generate, around said pads 11 and 16, a magnetic field, in particular an electromagnetic field, of adjustable intensity.

A cycle or process for coupling a heel 4 of a given type to a relative upper 3 will now be described.

According to that illustrated in figures 1 to 4, said coupling procedure or cycle comprises an initial preparatory step, during which a finished model 19 of the shoe 2 is arranged with its heel 4 between the open jaws 6 and 7 and so as to arrange an axis 17 of said heel 4 in a position substantially parallel to the axis 10 and transversal with respect to the axis 15, and so that a rear profile 20 of the heel 4 of the model 19 is facing the concave surface 9 and a front profile 21 of said heel 4 is facing the concave surface 14.

Before the jaws 6 and 7 are moved towards the closed position (figures 3, 9 and 10) to clamp the heel 4 of the model 9 between them, the generator 18 is inactive and the particles that constitute the material 12 are loose and behave, for example, like grains of sand.

Next, still during the initial preparatory step, the jaws 6 and 7 are moved towards a closed position, so as to press the pads 11 and 16 against the rear profile 20 and, respectively, the front profile 21 of the heel 4.

Under the action of the pressure exerted by the jaws 6 and 7, the material 12 flows freely into the respective pads 11 and 16 so as to make the pads 11 and 16 assume an outer shape that hugs the rear profile 20 and, respectively, the front profile 21. In other words, the tightening of the jaws 6 and 7 on the heel 4 of the model 19 results in the formation of two half-impressions 22 and 23, the first of which is obtained on the pad 11 and the second on the pad 16, reproducing, together, the heel 4.

As clearly illustrated in figures 1, 3 and 4, since the jaw 6 projects beyond the- heel 4 of the model 19 when said heel 4 is locked between the jaws 6 and 7, a rear profile 24 of the upper 3 of the model 19 also contributes, to the formation of an end portion 25 of the half- impression 22.

When the jaws 6 and 7 are still in the closed position

(figure 3), the generator 18 is activated to magnetize the material 12 so as to block the relative particles in the positions assumed with respect to one another and to "freeze" the half-impressions 22 and 23, the stability of the form of which is proportional to the value of the magnetic field that is generated.

The initial preparatory step ends (figure 4) with the opening of the jaws 6 and 7 and the removal of the model 19, performed while maintaining the generator 18 active and, thus, maintaining the deformation of the half- impressions 22 and 23.

At this stage it is possible to manufacture a shoe 2 with a heel identical to the model 19 by inserting and locking (figure 9) a heel 4 between the open jaws 6 and 7, applying glue 26 to an upper surface 27 of the heel 4 and then placing an upper 3 on top of the upper surface 27. The correct positioning of the upper 3 on the heel 4 is guided by the portion 25 of the half-impression 22. Once assembled, the upper 3 is locked on the heel 4, preferably from the bottom, as in the example that is illustrated, by means of nails and/or screws.

Lastly the finished shoe 2 is released (figure 11) and the jaws 6 and 7 are moved away from one another.

During all the steps in the production process that is described with reference to figures 9 to 11 the generator 18 remains active so as to maintain the relative magnetic field active and the material 12 frozen in position inside the respective pads 11 and 16 , so as to preserve the shape of the half-impressions 22 and 23. The half-impressions 22 and 23 can thus be used to produce a plurality of shoes 2 of the same type.

In order to change the shape, or the type of shoes 2 to be manufactured, the generator 18 is deactivated and the ferromagnetic particulate material 12 demagnetized, so that the profiles of the pads 11 and 16 assume their original configuration (figures 1 and 2) .

New half-impressions 22 and 23 can be made, according to the profile of any other type of shoe 2, simply be repeating the initial preparatory step using a new model 19.

According to an alternative embodiment that is not illustrated, only one of the half-impressions 22, 23 is made in that only one of the jaws 6, 7 is fitted with the relative pad 11, 16, while the other may, for example, be fitted with a conventional contrast pad, made of an elastic material (e.g. foam rubber) . From the above it is clear that with the device 1 described herein, compared with the prior art solutions, not only is it possible to eliminate the operations involved in the external production, replacement and storage/re-cycling of the half-impressions 22 and 23, but it is also possible to adjust both the hardness of the half-impressions 22 and 23 according to the strength of the magnetic field that is produced, so as to clamp the heel 4 more or less firmly depending on specific production requirements, and the finish of the half-impressions 22 and 23 by using a material 12 with, a different grain size.