FIELD OF THE INVENTION

The present invention relates to the technical sector of leather-working. In particular the present invention relates to a method for cutting leathers. DESCRIPTION OF THE PRIOR ART

Leather articles, for example footwear, are known to be usually made by cutting the parts to be assembled starting from large-dimension leathers, which generally exhibit an irregular shape.

To make the cut in the leather so as to obtain the articles, for example an automatic cutting machine is used, comprising a horizontal work plane, permeable to air, on which the leathers to be cut are arranged. The machine comprises an aspirating source, arranged below the work plane, activatable so as to maintain the leathers stretched and still once arranged on the work plane.

When the leather is positioned on the work plane, a processor, associated to the machine, detects the perimeter of the leather to be cut, and on the basis of this determines the "placing" of the articles to be obtained. In other words, the optimal arrangement of the articles to be cut is determined on the leather, so as to occupy the greatest possible surface thereof, thus minimizing waste and preventing the profiles of the articles to be obtained from superposing on one another.

This arrangement is displayed on a monitor and controlled by an operator: the operator is able to identify any defects present on the leather and prevent the profiles of the articles to be obtained from being arranged at the detected defects.

Once the operation has been completed, the projector device associated to the processor projects a light beam containing the profiles of the articles to be obtained on the leather. The machine is provided with a cutting head, borne by a mobile carriage above the work plane and to which a precision tool is fitted (or cutting blade) so as to cut the leather at the profiles of the articles projected on the leather.

Following the cutting operations, the articles thus-obtained are removed from the work plane and another leather to be processed can be arranged thereon.

However, the above-described known solution exhibits some drawbacks.

In fact, the presence is required of highly-specialised labour for managing and monitoring the high-precision cutting operations. This obviously incurs a very high cost. Further, the tools/cutting blades used require length times for realising the cutting of the articles, and consequently offer a relatively low productivity .

These cutting tools, apart from being particularly expensive, are subject to rapid wear over time. Therefore it is necessarily to periodically replace them, with large investments to be borne and with the risk of machine downtimes of even significant entity.

Further, over time the surface of the work plane on which the leather is to be spread is subjected to inevitable damage due to the cutting blades: it is therefore necessary to replace the work plane (a very expensive operation), or involve the use of remedies to limit alteration thereof (which remedies can require considerable installation times).

SUMMARY OF THE INVENTION

The aim of the present invention is to obviate the above-mentioned drawbacks.

This aim is attained by disclosing a method for cutting leathers in accordance with claim 1.

The method of the present invention advantageously enables a significant reduction in costs and total times associated to the cutting of leathers for obtaining articles.

Primarily, the disclosed method means that the leather-cutting operations do not require the presence of specialized labour; the cut is done by punching, and the operator already has, represented on the leather, precise indications on how the cut is to be performed.

Secondly, the punches are usually present in the sector of leather-working, and therefore the disclosed method enables using tools already available, without having to make further investments.

Further, use of expensive tools and precision cutting blades of the prior art is not necessary, which tools among other things need to be frequently replaced (differently to the punches).

As will be clear to a technical expert in the sector, by punch is meant the tool, usually made of steel, with the relative cutter describing a closed line, used for cutting profiles outlined on leathers or other material, by pressing the punch thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the method for cutting leathers disclosed in the present invention are set down in the following description, done with reference to the accompanying figures of the drawings, in which: - figure 1 illustrates a positioning step of a leather to be cut on a work plane, according to the disclosed method;

- figure 2 illustrates a step of identifying a profile of articles to be obtained on the leather to be cut, according to the disclosed method;

- figure 3 illustrates a tracing step of the profile of articles to be obtained on the leather to be cut, according to the proposed method;

- figure 4 illustrates a cutting step of the leather by means of manual punching for obtaining articles according to the disclosed method. DESCRIPTION QF PREFERRED EMBODIMENTS

With reference to the accompanying figures of the drawings, the method for cutting leathers for obtaining at least an article, comprises, in succession, steps of: positioning the leather 1 to be cut on a work plane 3 (see figure 1); identifying on the leather to be cut a profile 20 of at least an article 2 to be obtained (see figure 2).

In particular, the method further comprises, in succession, steps of: tracing on the leather 1 to be cut the profile 20 of at least an article to be obtained that has been identified (see figure 3, in which the profiles 20 are represented with broken lines); transferring the leather 1 to be cut on which the profile 20 of at least an article to be obtained has been traced to a remote manual cutting station 4; cutting the leather 1 by punch 5 at the traced profile 20, so as to obtain the article 2 (see figure 4).

The method disclosed advantageously enables a considerable reduction on all costs associated with cutting leathers which have to be supported with the known methods.

In fact, with the method of the present invention, not only is the use of tools and/or precision cutting blades dispensed with, but it is further unnecessary to have specialized personnel present during the cutting operations. The use of punches 5, included in the present invention, does not in fact require any specialisations on the part of the operator doing the cutting, who sees trace lines on the leather 1 of the profiles 20 of the articles 2 and with a few simple operations can cut them (see figure 4).

The punch 5 (i.e. the closed line that the cutter defines) will therefore exhibit a conformation such as to coincide with the profile 20 of the article 2 to be obtained.

In detail, with reference to figure 4, in the preferred embodiment of the invention the punch 5 is positioned manually by the operator doing the cutting on the leather 1 (arranged on a plane) so that the cutter of the punch 5 is at the traced profile 20 on the leather 1. Therefore, the operator acts on a presser element 9 positioned above the plane on which the leather 1 rests, so as to exert a pressure on the underlying punch 5 and cut the leather 1 so as to obtain the article 2. Alternatively the punch 5 might be removably fixed to the presser element 9.

The use of punches 5 enables reducing cutting times significantly with respect to the prior art, increasing productivity in terms of articles realised (i.e. cut out) in a reference time period (for example a work shift).

The punches 5 not only have particularly low cost with respect to the tools of automatic machines for cutting leathers used at present; they also already exist in the industry of leather-cutting. The punches 5 are also available in multiple formats, dimensions and conformations, according to requirements.

It is important to note that the manual cutting station 4 can also be very far from the place where the tracing of the profiles 20 on the leather 1 is done (for example it can be in a different works), without there being any need for information-technology connections and/or last-generation technologies for information transfer. All the operator performing the cutting has to know is already traced and therefore well-visible on the leather 1.

The fact the cutting step is carried out in a different station to the work plane 3 prevents deterioration of the work plane 3 over time (in the prior art this deterioration is inevitable given the use of cutting blades directly on the work plane).

For example, the leather 1 to be cut can be arranged on a horizontal work plane 3, permeable to air, below which an aspirating source is positioned (not illustrated), activatable to maintain the leather 1 stretched and still on the work plane 3.

In an embodiment illustrated in the accompanying figures of the drawings, the step of tracing, on the leather 1 to be cut, the profile 20 of at least an article 2 to be obtained is realised by means of a plotter 6 (see figure 3). This enables further minimising the total costs and the times required for obtaining an article 2; the plotter 6 is not only economical but also particularly rapid in tracing the profiles 20 on the leather 1.

For example, the plotter 6 can be of the multi-head type, enabling a high productivity with respect to what is guaranteed using known methods.

In order to trace the profile 20 of at least an article 2 on the leather 1 to be cut, erasable ink can be used, or a UV ink (or in any case any type of ink). If UV ink is used, the operator cutting the leather 1 will be equipped with special goggles for detecting the profiles 20 traced on the leather 1 (situation not illustrated).

Alternatively the step of tracing the profile of at least an article 2 to be obtained on the leather 1 can be realised using a laser (this variant is not illustrated). This guarantees a greater tracing precision of the profile 20.

In this last case, the tracing of the profile 20 of at least an article 2on the leather 1 can consist of an incision.

The plotter 6 or the laser can be advantageously borne by a carriage 8 acting on the work plane 3, as can be seen in figure 3.

In particular, the step of tracing the profile 20 of each article 2 to be obtained on the leather 1 is done in such a way that each profile 20 is in practice displaced externally with respect to the effective outline (i.e. the surface) of the corresponding article 2 to be obtained. This specification takes account of the thickness of the punch 5 (in particular the cutter thereof), in such a way that following the cutting step the articles 2 are not under-dimensioned, but exhibit the desired dimensions. Usually the perimeter of the leather 1 to be cut is acquired (i.e. scanned), once the leather 1 has been arranged on the work plane 3, by means of use of a processor. On the basis of the perimeter detected, the "placing" of the articles 2 to be obtained is mapped out, i.e. the optimal arrangement of the articles 2 to be cut from the leather 1 is determined, minimizing waste and at the same time preventing the profiles 20 of the articles 2 to obtained from overlapping one another.

This arrangement is displayed on a monitor 7 (see figure 2) and controlled by an operator: the operator is able to identify any defects present on the leather 1 and prevent the profiles 20 of the articles to be obtained from being arranged in positions where defects have been detected.

Obviously, during the placing operation, the processor takes account of the displacement of the profile 20 of each article 2 with respect to the effective outline thereof. The step of identifying, on the leather 1 from which the profile 2 is to be cut, at least an article 1 to be obtained, can comprise the sub-step of projecting the profile 20 on the leather 1 by means of a light beam (for example a matrix or laser projector, a situation that is not illustrated).

Alternatively, the sub-step might not be included, and the profile 20 of the identified article 2 (and displayed for example on the monitor 7) might not be projected onto the leather 1 to be cut; the step of tracing the profile 20 of the article 2 on the leather 1 can thus be done directly.

The above-described method, and claimed in the following, can however be applied to different materials to leather, for example in the form of single or multi-layer panels, more or less flexible.

The above has been described by way of non-limiting example, and any eventual constructional variants are understood to fall within the protective scope of the present technical solution, as claimed in the following.