APPARATUS FOR REACTIVATING ADHESIVE SUBSTANCES ON FOOTWEAR PARTS

FIELD OF THE INVENTION

The present invention concerns an apparatus for the reactivation, by heat, of adhesive substances previously applied on complementary footwear parts, such as for example an upper and a sole, or an insole and a sole, or others.

BACKGROUND ART

It is a known technique, especially in the industrial environment, to fix complementary footwear parts by means of reciprocal gluing obtained by applying, onto the surfaces to be joined of said complementary footwear (shoe) parts, a layer of an adhesive substance, for example a neoprene or polyurethane glue, of the type with a water base, or a thermoplastic resin.

In short, this technique consists of first applying a suitable glue, or adhesive substance, on the surfaces of the footwear parts to be stuck together, then drying it, preferably in an oven, to favour optimal adhesion of the glue to the surfaces to be stuck, and also to prevent oozing of the liquid glue onto surfaces of the shoe that should not be concerned in this operation, and finally, after a suitable phase of thermally reactivating the glue, the mechanical union of the parts to be stuck together.

In particular, the phase of thermally reactivating the glue previously applied and dried on complementary parts of the same shoe may preferably by carried out by simultaneously subjecting both shoe surfaces to be glued to a flow of heat, generated for example by quartz lamps, or by other infrared lamps, or even by ordinary electric resistances, even provided by a flow of fluid, at a set temperature and for a predetermined period of time.

For example, the patent US 2,549,981 in the name of MAESER, teaches how to reactivate at the same time the glue previously spread on the complementary surfaces of the sole and the respective upper of a shoe, by means of a flow of humid air at a given temperature. In greater detail, the MAESER apparatus contemplates that the sole and the upper, on which the respective dried glues are to be reactivated, shall be laid on two superposed perforated trays, through which passes a flow of suitably heated humid air, coming from a boiler below. The top tray, shaped to support an upper, is fixed and placed above the structure of the apparatus, while the bottom tray, shaped to hold the respective sole, moves parallel to the top tray, farther from or closer to it, in such a way as to facilitate loading of the soles, which may even have different dimensions.

The European patent application EP 0 092 320, in the name of THE BRITISH UNITED SHOE MACHINERY CO. LTD., teaches how to realise an apparatus for reactivating glues, previously applied on complementary footwear parts, comprising two pairs of superposed supports, mounted on a box-shaped structure, which also houses a heater, of the type with a radiating surface, having electric resistances to activate it.

The complementary footwear parts are manually loaded and unloaded and, while the top support is located above the apparatus, the bottom support is adjustable in height with respect to the top one, in order to allow the loading of soles with different sizes (for example soles that will have a heel).

None of the apparatuses described above contemplates a servo-assisted mechanism able to facilitate the movement of the sole support between an operative position, engaged with a suitable heater, and a position for loading/unloading the support, far from said heater.

Unlike the apparatuses described above, the reactivating machine Model 133, produced by the company ELETTROTECNICA B.C., contemplates that, within a box-shaped structure that houses one or more heaters with infrared lamps, a vertical pin is housed on which, in diametrically opposite positions, are mounted two trays that can be adjusted in height on said pin, for two soles, or other footwear parts with a limited thickness. The aforesaid pin can be rotated in a way commanded partly by the operator, so that the operator can move alternately the one and the other support engaged with the machine heaters and in a loading/unloading position, while the top wall of the box-shaped structure, suitably perforated, provides a support for the uppers, with the respective lasts, or for other complementary footwear parts, which is always functionally engaged with said heaters.

Even though the apparatuses of the prior art, and above all the machine produced by ELETTROTECNICA B.C., are fairly efficacious and functional, none of them contemplates any particular device for supporting shoe uppers, or other footwear parts, that have a shape and/or dimensions such that the aforesaid footwear parts are difficult to hold in position on the apparatus, or that even form an obstacle to the regular operation of the reactivating apparatus.

For example, when the uppers to be subjected to reactivation are composed of boot uppers, especially with a long leg, there often arises the problem that the boot leg is arranged on the reactivating apparatus in such a way as to hinder its accessibility, or in such a way as to force the glued surface of the upper to be unduly tilted with respect to the relative support of the reactivating apparatus, with the resulting non optimal heating of said glued surface.

Moreover, although said apparatuses, and in particular the one produced by ELETTROTECNICA B.C., may contemplate that the sole support can be removed or moved away from its operative position (subject to the heater), none of the known reactivating apparatuses contemplates that also the upper support can be removed or moved away from its operative position, so that said upper support is always subject to said heater. This forces the operator to load and unload the two supports at different times and in different thermodynamic conditions, with possible different reactivating conditions of the adhesive substances applied on the upper and on the sole.

US 3 256 420 A and DE 855 371C disclose the features of the preamble of claim 1.

An aim of the present invention is therefore to realise an apparatus for the reactivation of adhesive substances applied beforehand on complementary footwear parts, which does not have the disadvantages described above of the prior art.

An aim of the present invention is therefore to provide a reactivating apparatus for footwear parts that is particularly efficacious and, at the same time, that is highly practical in use, even when the footwear parts to be processed have considerable dimensions, such as uppers for boots with long legs.

SUMMARY OF THE INVENTION

These and other aims are achieved by the reactivating apparatus for complementary footwear parts according to the first independent claim and the subsequent dependent claims.

The apparatus for the reactivation of adhesive substances applied beforehand on complementary footwear parts, according to the present invention, comprises the features of claim 1.

This solution, as an expert in the sector will clearly understand, allows the increase of the efficiency of the loading and unloading operations of the footwear parts, that are preferably complementary, thus increasing the apparatus production rate.

Moreover, by suitably regulating the reciprocal position of the two supports, this solution allows easy support even of uppers, or other footwear parts, having large shapes and/or dimensions.

According to a preferred aspect of the present invention, the two supports of this pair of supports are superposed and fitted in a rotating manner on a pin, preferably vertical, with servo-assisted operation, controlled by the operator.

According to another preferred aspect of the present invention, the reactivating apparatus contemplates two pairs of supports, mounted on a vertical pin, in such a way that the vertical position of at least one of the supports on said pin can be adjusted by the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will now described, purely as an example without limitation, with reference to the enclosed figures, wherein:

• figure 1 is a perspective schematic view of an apparatus according to a particular aspect of the present invention;
• figures 2a and 2b are perspective schematic views of the apparatus in figure 1, taken in two different moments, during its operation;
• figure 3 is a partial schematic view, in perspective and partly in cross-section, of the apparatus in the preceding figures; and
• figure 4 is a perspective view of a particular support for footwear parts used in the apparatus in the preceding figures.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

With reference in general to figures 1, 2a and 2b, the apparatus for the reactivation of adhesive substances, applied beforehand and dried on preferably complementary footwear parts, comprises a frame 1 on which are mounted two devices 3, 4 for emitting heat, or heaters, two pairs of supports 5a, 5b and 6a, 6b for footwear parts (of which, in the figures, is shown as an example only one upper 100 - with respective last - of a boot with a long leg), and a control panel 2, for the manual adjustment of the apparatus operating parameters, and a pedal control 8 for activating the apparatus.

The supports of each pair of supports 5a, 5b and 6a, 6b for footwear parts 100 are, according to the present invention, movable, integrally with one another, between a heating position, engaged with a respective heater 3, 4, and a position for loading/unloading the footwear parts 100, distant from the respective heating devices 3, 4.

In this way the supports 5a, 5b or 6a, 6b of each pair of supports can support respectively two complementary footwear parts to be glued after reactivation, such as for example an upper with respective sole, and can therefore be simultaneously engaged functionally with a respective heater 3, 4, until the respective reactivation of the adhesive substances applied on both the parts to be glued, when, also simultaneously, they can be moved away from said heaters 3, 4, into a position where it is easy for the operator to unload them and load new footwear parts to be subjected to a new reactivating operation. More particularly, in the apparatus illustrated here, the frame 1 is box-shaped (substantially in the shape of a parallelepiped) with a front compartment in which are placed, horizontally and superposed parallel to each other, two heaters 3 and 4.

These heaters 3 and 4, shaped to emit a flow of heat from the respective lower horizontal surface (radiating surface), may preferably be of the type with lamps that emit light in the infrared field.

The supports 5a, 5b and 6a, 6b of each pair of supports for footwear parts 100 are integrally fastened, one over the other, in such a way as to extend horizontally and parallel to each other, to a vertical pin 7, which is fitted on the frame 1 rotating around its own axis.

The supports 5a, 5b of a pair of supports are also fastened to the pin 7 in such a way that they are diametrically opposite (that is at 180°) the corresponding supports 6a, 6b of the other pair of supports, with respect to the axis of the same vertical pin 7.

Moreover, due to the particular arrangement of the supports 5a, 5b and 6a, 6b in the apparatus illustrated here, the top supports 5a, 6a of the two pairs of supports must be placed engaged, that is above the respective radiating surface, only with the top heater 3, while the bottom supports 5b, 6b may be placed engaged, under the respective radiating surface, only with the bottom heater 4.

The vertical pin 7, which extends along the whole length of the compartment of the frame 1, corresponding to its front opening, and which may be activated in a way controlled by the operator, thus allows, in its predefined angular position (see for example figure 2b), the engagement of a pair of supports 6a, 6b with the respective heaters 3 and 4, in a position for heating the footwear parts being processed, and simultaneously the disengagement of the other pair of supports 5a, 5b of said heaters, in a position where it is easy to load and unload other footwear parts to be processed, and vice versa.

In fact the rotation of the pin 7, as may be seen for example in figure 2a, easily allows the exchange, by rotation, of the positions reached by each pair 5a, 5b and 6a, 6b of supports for footwear parts 100, in such a way that each pair 5a, 5b and 6a, 6b alternately reaches the aforesaid heating position, engaged with the heaters 3 and 4, and the aforesaid loading/unloading position, distant from said heaters 3, 4.

This rotation of the pin 7, according to a particular aspect of the present invention, as already said, can be manually controlled by the operator and also be servo-assisted, for example by an electric motor (of which a shaft 13 is illustrated in figure 3) commanded by the operator using the pedal control 8.

Now with reference also to figures 3 and 4, each support 5a, 5b, 6a, 6b, according to a particular aspect of the present invention, can comprise a bracket 11, with a square shape, intended to be fixed integrally to the pin 7, for example with one or more screws which engage in the respective holes 12 provided in said pin 7.

It should be noted that, as illustrated in figure 3, the pin 7 has a plurality of holes 12 in which it is possible to fasten alternatively the bracket 11 of each support 5a, 5b, 6a, 6b, in such a way that the operator can freely decide the respective vertical position of each support 5a, 5b, 6a, 6b on the pin 7, depending also on the dimensions of the footwear parts to be processed.

In the embodiment illustrated here, for example fixing the brackets 11 of the bottom supports 5b, 6b in a position closer to the radiating surface of the heater 4, and eventually adjusting the power emitted by the latter separately from the adjustment of the power of the heater 3, it is possible to process even uppers 100 of boots with a long leg, as may be seen in the enclosed figures.

To hold the footwear parts to be processed, the bracket 11 has, integrally fixed to it, two parallel rods 9a, 9b which support, in turn, respectively, two baffles 10a, 10b, that rotate around the respective rod 9a, 9b and are elastically fitted onto them(for example with a return spring).

More particularly, these baffles 10a, 10b are shaped (for example see figure 3) in such a way as to hold the various footwear parts 100 to be processed, for instance uppers or soles, and are also returned, by suitable elastic means (not shown, and interposed between them and the respective rods 9a, 9b) towards their position of rest, in which said baffles 10a, 10b extend substantially along the semi-plane ideally defined and bounded by the two rods 9a, 9b.

Each support 5a, 5b, 6a or 6b, can also comprise transverse bands 14 as auxiliary support for the shoe part 100 to be processed which, being movable along the rods 9a, 9b or even removable, allow each support 5a, 5b, 6a, 6b, to be adapted to the different dimensions of the footwear parts to be processed.

The operation of the apparatus described above is as follows.

When the operator intends to subject two complementary footwear parts to reactivation, for example the upper 100 of a boot and the respective sole, he will rotate the pin 7, so that, with reference to the position in figure 1, a pair of supports 5a, 5b reaches loading/unloading position, distant from the respective heaters 3 and 4. In this loading/unloading position, the superposed supports 5a and 5b are in a position substantially facing the operator.

In the case of the upper 100 and of the respective sole, the operator will lay the sole on the top support 5a, substantially resting between the baffles 10a, 10b which, due to the dimensions and the weight of the sole, are not rotated, and will insert the upper 100, with the respective last, between the two rods 9a, 9b of the bottom support 5b, in such a way that the respective baffles 10a, 10b turn around the rods 9a, 9b, in a position, contrasted by the aforesaid elastic return devices, in which the upper is firmly held between them (see figure 4).

At this point the operator will turn the pin 7, for example pressing the pedal 8 (see figure 2a) to bring the pair of supports 5a, 5b into said heating position, in which the top support 5a, which holds the sole (not shown) of the shoe to be glued, is placed under the radiating surface of the top heater 3, and at the same time the bottom support 5b, which holds the respective upper 100, is placed under the radiating surface of the bottom heater 4.

In this position of the pin 7, shown in figure 3, the other pair of supports 6a, 6b is in the loading/unloading position, in which the operator can easily unload any footwear parts already reactivated, and held by said pair of supports 6a, 6b, and can eventually load new complementary footwear parts to be processed.

At the end of processing of the footwear parts placed on the supports 5a, 5b, the further rotation of the pin 7, commanded by the operator, will bring the pair of supports 5a, 5b into the aforementioned loading/unloading position, where the operator can unload the sole and upper 100 from the respective supports and eventually load new footwear parts to be processed, and at the same time bring the other pair of supports 6a, 6b into the aforementioned heating position, engaged with the heaters 3 and 4. The repetition of these operations enables multiple complementary footwear parts to be subjected to the reactivation process in sequence.

It should be noticed that, thanks to the fact that the two complementary footwear parts to be glued are subjected to reactivation simultaneously for the same length of time, this reactivation of the adhesive substances is optimal and allows an extremely efficacious subsequent reciprocal gluing phase.

Moreover, as the expert in the sector can easily understand, not only does the apparatus described here allow uppers, or other footwear parts, having considerable dimensions and/or an irregular shape (such as for example the uppers of boots with a long leg) to be processed easily and without inconvenience, but it also increases the production rate of the reactivation process, allowing the support loading and unloading operations, while at the same time other footwear parts are undergoing the reactivation heat treatment.