METHOD AND APPARATUS TO TREAT FOOTWEAR NEAR THE END OF

THE PRODUCTION PROCESS

DESCRIPTION

The object of the present invention is a method for treating footwear near the end of the relative production process and an apparatus for implementing said method, to be preferably, yet not exclusively, used in industrial footwear manufacturing plants.

It is known that the industrial footwear production process provides, near the end of its conclusion, the execution of a refrigerating phase in a refrigerating unit, so as to take this footwear to a refrigerated condition. This refrigerating phase is necessary in order to stabilize the adhesive capacity of the gluey substances employed in the preceding processing phases to assemble the footwear. This refrigerating phase is set up on an industrial scale in appropriate apparatuses that essentially comprise a supporting structure, transporting means supported by said supporting structure so as to transport said footwear from a loading station to an unloading station and a refrigerating unit placed alongside said transporting means and supported by said structure to take said footwear to a refrigerated condition. In detail, the operation of said apparatus is as follows. The footwear to be treated is manually set up in homogeneous groups on the transporting means next to the loading station. The transporting means then gradually carry these footwear groups from the loading station, through the refrigerating unit in which they are taken to a refrigerated condition, to the unloading station where they are held for a waiting period. During this period the footwear gradually passes from a refrigerated condition to a natural condition due to the contact with the natural environment. At the end of this resting period, the operators provide for drawing and packing up said footwear.

The main drawback found in the method and in the relative apparatus according to the art described above consists in that they promote the appearance of antiaesthetic mildews on the surface of the footwear and occasionally inside the same, even at a distance of months from their production, which originate complaints and requests for a recall and refund

on the part of the resellers against the producers. This drawback derives from the fact that the contact of the footwear with the natural environment in a refrigerated condition determines the formation of micro-phenomena of condensation on the surface of and inside said footwear. Said condensate consequently tends to stagnate in the footwear and to favor the birth and development of fungal formation, in particular when the footwear is packaged in the appropriate packing boxes. Said drawback is encountered to a more serious extent in the footwear produced during the hot and moist season and in countries with a tropical climate, because the relative climatic conditions are obviously such as to accentuate the appearance of the mentioned micro- phenomena.

A second drawback found in the apparatus according to the prior art above described consists in that the transporting means tend to stain the soles of the footwear. In particular during the production of footwear with natural leather soles, this method and the relative apparatus are rarely employed, in order to prevent the appearance of these defects on the footwear as much as possible. This entails the fact that the production cycle of this footwear is considerably lengthened, and that the production costs consequently rise. This drawback is caused by that the frozen condensation that builds up on the surface along the transporting means during the passing of the latter in the refrigerating unit thaws up to form minute droplets during the external passing of said transporting means outside said refrigerating unit. The footwear soles placed in contact with the transporting means consequently tend to absorb the condensation that causes the mentioned defects.

A third drawback found in this method and in the relative apparatus according to the prior art consists in the mentioned standby period, which represents a dead period in the footwear production cycle. The footwear in fact arrives at the loading station at the refrigerated temperature, which is unsuitable to allow its handling. For this reason, the mentioned footwear is stored in collection bins. In order to allow the operators to perform the subsequent operations on this footwear, it is consequently necessary to wait

until the footwear assumes the temperature of the natural environment.

The aim of the present invention is to set up a method and apparatus to treat footwear near the end of its relative production cycle, so as to be able of resolving the drawbacks and problems found in the methods and in the relative apparatuses according to the prior art described above.

Within this aim, an important object of the present invention is to set up a method and apparatus to allow preventing the formation of stagnating condensate both on the surface of and inside the footwear.

Another object of the present invention is to set up a method and apparatus suitable for an application on any type of footwear without dependence on the materials of the soles.

A further object of the present invention is to set up a method and apparatus able of allowing a reduction in the duration of the footwear production cycle. Another object of the present invention is to set up an apparatus with limited production and maintenance costs.

Not the last object of the present invention is to set up an apparatus to allow containing the energy consumption deriving from its operation.

This aim, as well as these and other objects that will be better apparent in the following, are achieved by a method and by an apparatus for treating footwear near the end of their relative productive process, according to the attached claims.

According to first advantageous features of the invention, the method comprises a refrigerating unit to take this footwear to a refrigerated condition, and a heating phase in a heating unit subsequent to said refrigerating phase, to take said footwear from said refrigerated condition to a heated condition at a temperature at least higher than the temperature of the natural environment.

The apparatus in turn comprises a supporting structure, means of support supported by said supporting structure to transport said footwear from a loading station to an unloading station, a refrigerating unit set up along said transporting means and supported by said structure in order to take said

footwear to a refrigerated condition, and a heating unit set up downstream of said refrigerating unit along said transporting means and supported by said structure to take said footwear from said refrigerated condition to heated condition, at a heating temperature at least higher than that of the natural environment.

This solution achieves the object of eliminating the stagnation of condensate on the footwear and of rendering the method and apparatus suitable for an application on any footwear. In fact, the heating phase allows drying the condensate that appears on said footwear and partially on said refrigerating unit when passing from said refrigerating unit to said natural environment and, correspondingly, the heating unit is able of drying the condensate that appears on said footwear and on said transporting means while passing from the refrigerating unit to the natural environment. This solution is therefore able of eliminating the problems of the appearance of mildews as well as of stains.

This solution also achieves the purpose of shortening the footwear productive process. In fact, the heating phase and heating unit allow the footwear in a refrigerated condition to attain a natural condition in a very limited lapse of time. This solution therefore allows substantially reducing the footwear productive cycle.

According to second advantageous features of the invention, the heating unit comprises a heating tunnel supported by said structure, which is set up near the end of the unloading station and crossed by said transporting means, a heating chamber limited in its upper part by said heating tunnel and in its lower part by said transporting means, and heating means set up inside said heating chamber.

This solution achieves the object of containing the construction and the maintenance costs. In fact, it appears to be simple in an overall sense, both from a designing viewpoint as from a construction viewpoint. According to further advantageous features of the invention, the heating means comprise heating means by radiation and by convection, respectively.

This solution achieves the object of containing the energy consumption deriving from the operation of the heating unit. In fact, the heating means exploit both the heating action provided by beams of radiation as well as that generated by air currents. Further features and advantages of the invention will become better apparent from the description of an embodiment of the method and the apparatus for treating footwear near the end of their relative production process, as illustrated for indicative but not limiting purposes in the enclosed drawings, in which: - Figure 1 represents a prospective view of the apparatus according to the invention, in a non-operating condition;

Figure 2 represents a side view of the apparatus of Figure 1 in a non- operating condition;

Figure 3 represents a side view in a longitudinal section of the apparatus of Figure 1 and of Figure 2 in an operating condition;

Figure 4 represents a view in a transversal section made next to the heating unit of the apparatus of the preceding figures.

The method for treating footwear near the end of the relative productive process comprises above all a refrigerating phase in a refrigerating unit, to take said footwear to a refrigerated condition.

This method also comprises a heating phase in a heating unit subsequent to said refrigerating phase, to take said footwear from said refrigerated condition to a heated condition at a heating temperature at least higher than the temperature of the natural environment. In this way, the heating phase allows drying the condensate that appears on this footwear and partially on said refrigerating unit when passing from said refrigerating unit to said natural environment. In detail, said heating phase has a duration that allows said footwear to attain said heating temperature uniformly and in depth. Moreover, said duration is a function of the type, the formation and the materials of this footwear. This heating phase is also implemented by subjecting said footwear to beams of infrared light and to flows of preheated air. In this way, the heating temperature attained is approximately in the

range between +40° C and + 100 ⁰ C.

With reference now to the figures in the enclosed drawings, the apparatus for treating footwear is indicated as a whole by the reference number 5. First of all, the apparatus 5 comprises a supporting structure 6 that comprises in turn a carrying frame 7 and a plurality of coating panels 8.

This apparatus 5 also comprises transporting means 9 supported by said supporting structure 6 to transport said footwear from a loading station 10 to an unloading station 11. In detail, these transporting means 9 comprise a conveyor belt 12 for transporting said footwear from said loading station 10 to said unloading station 11 , a pair of step-wise forward moving motors 13 supported by said structure 6 for a stepwise forward motion of said conveyor belt. In even more detail, said conveyor belt 12 defines, between said pair of forward moving motors 13, a transfer plane 14 of said footwear, which lies in a horizontal plane. Said pair of forward moving motors 13 is in turn positioned next to the upper lateral and distal extremities of said structure 6.

Said apparatus 5 also comprises a refrigerating unit 15 placed along said transporting means 9 and supported by said structure 6 to take said footwear to a refrigerated condition. In detail, said refrigerating unit 15 comprises a refrigerating tunnel 16 supported by said structure 6, a refrigerating chamber 17 defined in its upper part by said refrigerating tunnel 16, and in its lower part by said transporting means 9 and said refrigerating means 18 which are housed in said refrigerating tunnel 16 for refrigerating said footwear. Said refrigerating tunnel 16 is appropriately placed near said loading station 10 and is crossed by said transporting means 9. Also appropriately, said refrigerating means 18 generate a flow of air which is channeled from the bottom to the top, so as to first cool the sole and subsequently the vamp.

Moreover, said apparatus 5 comprises a heating unit 19 set up downstream of said refrigerating unit 15 along said transporting means 9 and supported by said structure 6 to take said footwear from said refrigerated condition to a heated condition at a heating temperature at least higher than

the temperature of the natural environment. In this way, the heating unit 19 dries the condensate that appears on said footwear and on said transporting means 9 during the passage from said refrigerating unit 15 to said natural environment. In detail, said heating unit 19 comprises a heating tunnel 20 supported by said structure 6, a heating chamber 21 limited in its upper part by said heating tunnel 20 and in its lower part by said transporting means 9, and heating means, indicated as a whole by the reference number 22, set up inside said heating chamber 21. Said heating tunnel 20 is appropriately set up near said unloading station 11 and is crossed by said transporting means 9. Even more in detail, said heating means 22 comprise heating means by radiation and by convection, respectively. Said heating means by radiation consequently comprise first and second infrared radiating panels 23, 24 applied to said heating tunnel 20, which emit beams of infrared radiation that impinge on said transporting means 9 and said footwear carried by said transporting means 9. Said first and second radiating panels 23, 24 are attached in a condition opposite to the ceiling and the pavement, respectively, of said heating chamber 21. Said first and second infrared radiating panels 23, 24 advantageously exhibit a first surface color in a non- operating condition, and a second different surface color in an operating condition. In turn, said convection heating means comprise inlet fans 25 that aspirate fresh air from outside said heating tunnel 20 across aspirating slots provided in said heating tunnel, and convey it into said heating chamber 21 , and evacuating fans 26 that aspirate heated air into said heating chamber 21 and evacuate it to the outside of said heating tunnel 20 through evacuating slots provided in the heating tunnel 20. In detail, said inlet fans 25 are applied to the lateral walls of said heating chamber 21 and above said transporting means 9, and said evacuating fans 26 are applied to the ceiling of said heating chamber 21.

In this way, the aforesaid heating temperature achieved is comprised in the range from +40 ⁰ C to +100 ⁰ C.

In conclusion, the apparatus 5 comprises programming means 27, 28 to program the working parameters characteristic of this apparatus 5, such as

the retention time of said footwear in said refrigerating chamber 17 and in said heating chamber 21 , the refrigerating and the heating temperatures, etc.

The operation of this apparatus occurs essentially as described below, with reference to the enclosed figures. First of all, by using the programming means 27, 28 the operator sets up the characteristic working parameters based on his experience and the type of footwear to be treated. The footwear to be treated is then disposed in homogeneous groups on the transporting means at the loading stations 10. The transporting means then gradually carry these footwear groups from the loading station 10 first through the refrigerating unit 15 where they are taken to a refrigerated condition, then through the heating unit 19 to take said footwear from said refrigerated condition to a heated condition at a heating temperature at least higher than the temperature of the natural environment, and finally to the unloading station 11 , from where it is drawn. In detail, in said heating unit 19 the footwear and transporting means 9 undergo the combined heating action exercised by the radiation and convection heating means that determine the drying of the condensate on the footwear and on the transporting means 9.

It was in practice found that the method and apparatus thus described achieve the expected aim and objects. First of all, it was found that the method and apparatus are able of preventing the formation of condensate stagnating points both on the surface and inside the footwear. It was also found that that the method and apparatus are suitable for an application on any kind of footwear without dependence on the materials of the soles. It was also found that the method and apparatus are able of reducing the lenght of the footwear production cycle. It was further found that the apparatus involves limited production and maintenance costs. It was finally demonstrated that said apparatus allows minimizing the energy costs deriving from its operation.

The method and apparatus according to the invention are susceptible of numerous modifications and variations, all falling within the scope of the appended claims.

In a practical realization, the materials used, the forms, the dimensions

and the executive details may differ from those outlined above but be their technical equivalents, without thereby leaving the scope of the invention.