"A device for delivering an humidified gas flow "

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DESCRIPTION FIELD OF THE INVENTION The present invention concerns to a device for delivering a humidified gas flow to process footwear portions, or portions of leather goods or of saddlery, comprising a first duct for transferring a gas, or gas mixture, usually air, and a second duct for transferring steam, which are fluidically connected to a mixing chamber from which, through the outflow section of an appropriate delivering nozzle, the gas and steam mixture, formed therein, may reach the footwear portion, or portions, in process. Such a device is particularly used in an equipment for pressing (i.e. ironing) leather, both natural and synthetic, or footwear fabric, or leather goods or saddlery, or portions thereof, in the footwear manufacture field, or in the field of leather goods or saddlery such as shoes, slippers, boots, handbags, bags, saddles, etc. It has to be observed that, although in the rest of this document preferably it will be referred to footwear processing, it has to be understood that the device, object of the present invention, may be equally used for working leather goods or saddlery, or of another clothing industry, or personal clothing accessories, that does use fabrics, non - woven fabrics, leathers, synthetic materials, or any others not mentioned yet, provided that it needs a thermic treatment with a humidified gas flow. BACKGROUND ART

It is known art to submit portions of the footwear in process, before their ultimate assembling, to pressing operations of the leather, frequently necessary because of the possible formation of wrinkles, folds, gathers, or other superficial unevenness, due to the common processing of sewing, shaping (lasting) or finishing of a footwear.

Similar pressing operations may concern the leather or fabric of handbags, bags, saddles, or other leather goods or saddlery, wherein folds or other superficial unevenness have formed during the processing of their manufacture. Such operations for pressing leather may be carried out by a mechanical treatment of compression and stretching the leather, or fabric, which may be preceded, or contemporary placed in process, by a thermal treatment wherein heated air and / or

steam jets are directed to the leather, or fabric, to be pressed.

For example it is known how to maintain stressed portions of the footwear in process, for example the upper, on the corresponding last and then to submit such a portion of the footwear to a steam jet, or jet of humidified hot air, to smooth possible wrinkles made up on the leather.

Alternatively, the Application WO-A- 2006/111808, in the name of COTTINO, describes an equipment for the leather pressing of a footwear in process comprising a head delivering a steam jet and/or hot air jet mixed with steam, and a pressing hammer for the leather previously subjected to the steam jet or steam - humidified air jet.

In case of process with a hot air jet mixed with steam, that is humidified hot air, it is found that as the temperature reached by the hot air jet increases, as long as it is adequately mixed with water vapour, an appreciable reduction of time necessary to obtain the desired leather softening is obtained, without damaging the leather itself because of such an high temperature.

For example, it has been found that temperatures of 300 - 500 °C for the hot air jet, if conveniently mixed with a steam jet at 100 - 110 °C, at appropriate flow rate, are the most recommended to maximize the efficiency of the leather pressing operations using humidified hot air. The Patent GB-A- 978154, in the name of TASSI, teaches to realize a device for delivering humidified hot air jet wherein an air jet, heated by an electric heater, is mixed with a steam jet, produced by an appropriate boiler, inside a transferring tube for fluids ending into a delivering nozzle. Therefore, in the known art devices, completely similar to that described in the TASSI's Patent, the mixing of the hot air flow with the steam flow happens upstream the delivering nozzle, that is at an appreciable distance from the outflow section of the latter.

In other devices of the known art, the steam flow, before of its possible mixing with the air flow, hits the duct, usually metallic, for transferring the heated air flow itself for a long length into a closed area acting both as a steam storage reservoir, and a mixing chamber for the two fluids, placed upstream the afore said delivering nozzle.

Herein and the following it has to be observed that with the term "delivering nozzle" it has to be intended that particular component provided with an outflow section for fluids that is opened towards the outer environment, fluidically connected with the fluid transferring ducts themselves and intended for operatively engagement with the footwear portions in process.

Such arrangements of the fluidic equipment, substantially unimportant in case of maintaining the air flow at a temperature near the steam temperature, will became critical in case wherein the air temperature is much higher than 100 °C. In fact, in this latter case, the high air temperature, for example 300 - 400 °C, substantially prevents a correct steam mixing, usually at 100 - 110 °C, with the air jet, that is the correct mixing of a sufficient steam flow rate with the air flow and, in its turn, the relatively low temperature of the jet will. tend to appreciably lower the temperature of the air jet itself, such that it is extremely difficult, if not impossible, to obtain optimal steam flow rate and air jet temperature conditions allowing an efficient pressing of the leather of the footwear in process.

At last it has to been observed that, although it has previously described the application of a jet of hot humidified air to execute an operation for pressing leather or fabric, such an operation may find convenient use during other working processes of footwear portions too, or leather goods or saddlery, herein not specifically mentioned.

It is therefore an object of the present invention to provide a device for delivering a humidified gas flow to process footwear portions in progress, or portions of leather goods or saddlery, not presenting such drawbacks afore mentioned, and in the meanwhile showing high effectiveness during the working operations of a footwear. It is therefore an object of the present invention to provide a device for delivering a humidified gas flow allowing to submit at high temperature the footwear portions in process, or portions of leather goods or saddlery, to an air flow or other gas or gas mixture, that is further conveniently mixed with a steam flow of convenient flow rate. Another object of the present invention is to realize a device for delivering a humidified gas flow for treating portions of footwear, that is simple to realize and

easy to use.

SUMMARY OF THE INVENTION

These and other objects are carried out by the device for delivering a humidified gas flow for processing footwear portions, or portions of leather goods or of saddlery, according to the first independent claim and the subsequent dependent claims. According to the present invention, the device for delivering a humidified gas flow for processing footwear portions, or portions of leather goods and saddlery, comprises at least one first duct for transferring at least one gas, or gas mixture, usually air, and at least one second duct for transferring steam, which are fluidically connected to a chamber for mixing the gas flow with the steam flow, as well as a delivering nozzle for the mixed gas, or gas mixture, and steam. Advantageously, the device of the present invention provides the afore said mixing chamber to be placed immediately upstream the outflow section of the delivering nozzle. In this way, the heat transfer between the two fluids, which may have very different temperatures, is considerably limited, because of the geometric arrangement of the mixing chamber, immediately close to the outflow section of the delivering nozzle, with a consequent decrease of the drawbacks of the known art reported before. Such an arrangement of the mixing chamber, as the Applicant noticed, allows to maintain a gas flow, preferably air, at high temperature (up to 500 °C), humidified by a flow of water vapour having appropriate flow rate, with a consequent high effectiveness of such a treatment, most of all concerning the quickness of the obtained effect and correct humidification and heating of the leather, natural or synthetic, or the fabric of the footwear portions in process, or leather good or saddlery. According to a second aspect of the present invention, the device afore described further comprises means for substantially maintaining thermically insulated from one another the steam and the duct for transferring gas, or gas mixture, and / or the gas, or gas mixture, and the duct for transferring steam. Such means, that may comprise a tubular insulating sheath placed coaxially to at least part of the gas flow duct, or the duct for transferring steam, further keep down the magnitude and rate of heat transferring between the two fluids, rendering the

drawbacks afore described more limitative.

According to a further preferred aspect of the present invention, the device comprises at least one inlet reservoir for steam, placed upstream the afore said nozzle, wherein a conveniently insulated portion of the duct transferring the gas flow may be placed. Further, in a particular embodiment of the present invention, the device comprises means for heating gas, or gas mixture, up to a temperature higher or equal to 90 °C and preferably higher or equal to 300 °C, up to 500 °C and over.

BRIEF DESCRIPTION OF THE DRAWINGS

For purposes of illustrations and not limitative a preferred embodiment of the present invention will be described with reference to the accompanying drawings, in which: figure 1 is an outer perspective schematic view of part of the device according to a particular aspect of the present invention; figure 2 is a schematic view, partially cut - away, of the device of figure 1 ; and figure 3 is a front section expanded view of the device of the preceding figures.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE

INVENTION

Generally referring to the appended figures, according to a particular aspect of the present invention, the device 1 for delivering a humidified gas flow for treating portions of leather goods, saddlery or footwear, for example adapted for pressing operations of these latter, comprises an intake tube 2 of a gaseous fluid, made of gas or gas mixture, such as for example and preferably air A, that is fluidically connected to a first duct 8 for transferring such a gaseous fluid A towards a delivering nozzle 5, a second duct 3 for transferring a flow of steam V, a chamber 10 for mixing the steam V with the afore said gas, or gas mixture, A, as well as means 6, 15 to control the intake of gas, or gas mixture, A, from the afore said intake tube 2 to the first duct

8 for transferring such a gas, or gas mixture A.

According the known art, the device 1 further comprises means, not illustrated, for generating the steam V in preset and preferably controllable conditions of temperature and pressure, placed upstream the duct 3, as well as means, preferably

adjustable too, for providing a gas, or gas mixture, flow at a certain temperature and pressure to tube 2.

According to a characteristic aspect of the present invention, these latter means may particularly be able to lead the gas or gas mixture temperature (preferably air) up to a temperature between 90 ⁰ C and 500 °C, and preferably between about 300 °C and 500 °C. In the embodiment herein illustrated, such means comprise an electric heater 12, placed inside the tube 2, that is able to heat in an extremely rapid way the flow of air A, input by an appropriate impeller (not shown). In addition, according to the known art, the device 1 may be mounted, for example inside an equipment for leather pressing, such a way to be manually moveable relatively to a portion of the footwear, or the leather goods or saddler, in process, thanks to a handle 7.

It has to be observed that with the term "mixing chamber" here and later on it is intended any chamber of the device 1 according to the present invention wherein may happen the contemporaneous intake of fluids, gas or gas mixture A and steam V, such to allow their even partial mixing.

Here and later on it has further to be noticed that, for shortness, it will be explicitly referred to air A as a gas mixture transferred inside the tube 2 and the duct 8, although any other gas type, for example an inert gas, or having an appropriate gas mixture, may substitute air, if provided.

Therefore both the duct 8 for transferring air A, and the duct 3 for transferring steam V, are fluidically connected to the mixing chamber 10, directly or indirectly, being displaced such that the first contact of the flow of air A with the flow of steam V substantially happens in such a mixing chamber 10. Advantageously, according to the present invention, such a mixing chamber 10 is placed immediately upstream the outflow section 9 of the delivering nozzle 5, that is, in the particular embodiment of the invention herein illustrated, a side of such a mixing chamber 10 coincides with the outflow section 9 of the nozzle 5. Thereby the direct heat transfer between the two fluids A and V is limited only to the mixing chamber 10, placed close to the outflow section 9 of the nozzle 5, with consequent better mixing of the fluids A and V themselves, because of the reduced

heat transfer between the two fluids.

More in detail, the mixing chamber 10 of the device 1 is opened at the ending exit portion of the delivering nozzle 5, that is, in the particular embodiment of the present invention herein illustrated, directly and fluidically connected to a reservoir 4, 5 wherein the steam V, coming from the duct 3, will converge. The nozzle 5 houses portions of the duct 8 for transferring the air A as well, such that the outflow section 14 of such a duct 8 will open into the nozzle 5, thereby defining the afore said mixing chamber 10. Further, according to a particular aspect of the present invention, the device 1

10 comprises means 11 for maintaining substantially thermically insulated the steam V from the duct 8 transferring the air A. Such means, in the embodiment herein illustrated, are comprised of an insulating sheath 11, having tubular shape, displaced around at least part of the duct 8 transferring the air A in correspondence of that portion of duct 8 coming in contact with the steam V, upstream the mixing chamber

15 10, inside the afore said reservoir 4.

Such a sheath 11 , by way of example, may be realized in a synthetic insulating material, particularly adapted for low temperatures, or it may only be a metallic screen, adapted for high temperatures, that could define an air chamber around that portion of duct 8 for transferring the air A affected by the flow of steam V. 0 It has to be noticed that, alternatively or together, in possible further embodiments of the present invention, the device 1 may comprise means as well for substantially maintaining the air A thermically insulated from the duct 3 transferring the steam V. In this way, as afore said, the direct or indirect heat transfer between the two fluids A and V is much limited upstream the mixing chamber 10, with a consequent 5 improvement of the mixing efficiency of the fluids A and V themselves, that is with a consequent obtaining of the adequate conditions of steam flow rate and of temperature of the air jet exiting from the outflow section 9 of the nozzle 5. Particularly, the arrangement of the embodiment herein illustrated has been found much efficient in providing the afore said conditions of flow rate and temperature 0 considered optimal for the hides processing during the footwear manufacturing, while demonstrating to be compact and easy to realize.

More in detail such a structure, as can be seen in figures, provides the tube 2 for air A intake to be connected, through a chamber wherein an externally driven cut - off 15 may slide, to an inlet section 13 of the duct 8 for transferring the same flow of air A. Such a duct 8, in its turn, is expanded along the cylindrical reservoir 4, having a circular section, coaxially with such a reservoir 4, up to reach, with its outflow section 14, the delivering nozzle 15, placed at the ending downstream section of the reservoir 4 itself.

As it can be noticed from the figures, the tube 2 is substantially orthogonal to the duct 8 and partially houses the upstream end of the reservoir 4. In such a way, coaxially to the inlet section 13 of the duct 8, a user-driven cut-off 15 (belonging to the afore said means 6 to control the intake of air A inside the duct 8) may be placed, as mentioned, inside the same tube 2, the cut-off 15 being able to obstruct or not such an inlet section 13, denying or allowing the intake of air A inside the duct 8. The duct 8 for transferring air A is further surrounded by a tubular sheath 11, realized in a insulating or metallic material, with the interposition of an air chamber between the sheath 11 and the duct 8, extending for much of that length of duct 8 placed inside the reservoir 4, substantially starting from the inlet section 13 of the duct 8 itself. Such a sheath 11, that may be realized in stainless steel, must have such dimensions and characteristics to guarantee a good thermic (thermal) insulation between the steam V, contained inside the reservoir 4, and the duct 8 for transferring the air A.

The reservoir 4, cylindrical too and having a circular section, is further fluidically connected to the duct 3 for transferring the steam V, that is inserted, substantially in an orthogonal manner, into such a reservoir 4, in such a way that the outlet section of the same duct 3 will open inside the reservoir 4 in a position in front of a region of the insulating sheath 11.

It has to be observed that intake tube 2 of air A and the duct 3 for transferring the steam V are conveniently parallel from one another and separated by an appropriate distance, so that the thermal transfer because of conduction between the two ducts 2 and 3 is substantially not allowed.

The reservoir 4, having the function of allowing the outflow regulation of steam V

inside the mixing chamber 10 inside the delivering nozzle 5, is then fluidically connected at its outflow portion to such a delivering nozzle 5, which, in its turn, houses part of the duct 8 for transferring the air A, the outflow section 14 thereof will open inside the nozzle 4, defining the afore said mixing chamber 10, as mentioned. This latter, according to a particular aspect of the present invention, is preferably substantially cylindrical with a circular section and presents a section area between 25 and 2000 mm ² , and height between 1 and 50 mm, where with the "height" term is here intended the distance from the outflow section 14 of the duct 8 for transferring the air A and the outflow section 9 of the delivering nozzle 5, these sections being substantially reciprocally parallel.

The device operation herein shown is as follows.

When the operator wants to submit a portion of the footwear to process, for example an upper, to an air and steam flow, must first regulate the temperature conditions (for example 100 - 110 ⁰ C) and the flow rate of the steam V and the temperature conditions (for example 300 - 400 °C) and the flow rate of the air A, then he/she has to allow their inlet inside the tube 2 of air A intake and inside the duct 3 for transporting the steam V, respectively.

Then the flow of air A, heated for example almost instantaneously by the heater 12, will enter the duct 8 for transporting the air and from here will arrive, substantially insulated from the steam V, inside the mixing chamber 10 into the delivering nozzle 5.

The flow of steam V, in its turn, will enter into the reservoir 4, substantially insulated from the duct 8 thanks to the sheath 11, and from here will move into the mixing chamber 10, where it will mix with the flow of air A, at least partially, and almost immediately will exit with such a flow of air A from the outflow section 9 of the nozzle 5, because of the closeness of such a mixing chamber 10 with the outflow section 9 itself.

As the Applicant could find in practice, the flow of the humidified air A+V exiting from the nozzle 5 is in the most appropriate thermodynamic conditions for adequately humidifying and heating the leather of the footwear in process.

In case the operator wants to stop the air flow, although temporarily, exiting from the

duct 8, to allow the only humidification of the leather, it is sufficient he will act on the afore said means 6 to control the intake of air A, in such a way to engage the cutoff 15 with the inlet section 14 of the duct 8.

Vice-versa, when the operator would consider it is necessary to re-establish the flow of air and steam A+V directed to the portion of the footwear in process, he/she could act on the afore said means 6 in such a way to disengage, completely or partially, the cut-off 15 from the inlet section 14 of the duct 8 for transferring the air A. The use of the afore mentioned device 1, as the Applicant could verify, is particularly easy and effective, and its simple fulfilment led to a high reliability thereof.