Abstract:
A hemming system for hemming a fabric, without using seams, and by introducing an adhesively processed element into a surface or between two opposite surfaces of the fabric, comprises an adhesive applying module for applying two adhesive materials to an elastic or resilient element and to the fabric, and a second hemming module, for hemming the fabric at the resilient element.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a hemming system and method for hemming a fabric, without using seams, by introducing an adhesively processed elastic or resilient element into a surface or two opposite surfaces of the fabric. 
     The inventive system has been specifically designed to hem a fabric material, without performing seaming operations on the latter, while simultaneously providing an elasticized hem, adapted to provide the fabric material with a perfect elastic recovery property, allowing the elasticized fabric hem to be recovered to its starting position as a pulling or tension force applied to the resilient fabric hem is removed. 
     The above mentioned result, in particular, cannot be obtained, as it should be apparent to one skilled in the art, by using available single or multiple layer prior adhesive materials. 
     Multiple-layer adhesive materials and, in particular, three layer adhesive materials which, at least theoretically, would provide the fabric hems made thereby with a full recovery property, are already known. 
     In actual practice, the above mentioned adhesive materials, as they have been subjected to the required hemming temperature and pressure, are so modified that they cannot assure a recovery to the starting conditions of the fabric material. 
     This drawback causes a fabric material article made by the thus processed prior adhesive materials, to be undesirably elongated, with a consequent loss of its resilient and wearing properties. 
     SUMMARY OF THE INVENTION 
     Accordingly, the aim of the present invention is to provide such a hemming system and method, for hemming a fabric, without using seams, by introducing an adhesively processed resilient element into a surface, or two opposite surfaces, of said fabric, thereby allowing to overcome the above mentioned drawbacks of the prior art and providing very good results. 
     Within the scope of the above mentioned aim, a main object of the invention is to provide such a system and method which are operatively very flexible and adapted to allow a user to perform several types of hemming operations. 
     Yet another object of the present invention is to provide a cloth article, made from the above fabric material, having cloth article hems which are substantially improved, from an aesthetic and operating standpoint, with respect to prior fabric hems. 
     According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a system for hemming a fabric, without using seams, by introducing an adhesively processed resilient element into a surface or two opposite surfaces of said fabric, characterized in that said method comprises a first adhesive applying module for applying two adhesive materials to said resilient element and said fabric, and a second hemming module, to hem said fabric at said resilient element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative but not limitative example, in the accompanying drawings, where: 
         FIG. 1  is a schematic perspective view showing the first adhesive applying module or unit included in the hemming system according to the present invention; 
         FIG. 2  is a side elevation view illustrating the programmable tensioning or pulling device of the first adhesive applying module or unit; 
         FIG. 3  is a front elevation view, as partially cross sectioned, showing the adhesive applying module or device; 
         FIG. 4  is a further side elevation view, partially cross-sectioned, illustrating the adhesive applying module or device; 
         FIG. 5  is a further schematic view, on an enlarged scale, with respect to the preceding figures, showing details of a top hot air delivery device associated with the adhesive applying module; 
         FIG. 6  is a further schematic perspective view of the adhesive applying module; 
         FIG. 7  is yet another schematic perspective view of a feeding, pressing and trimming device included in the hemming system according to the present invention; 
         FIG. 8  is yet another schematic perspective view showing a second hemming module or unit included in the hemming system according to the present invention; 
         FIG. 9  is an enlarged-scale perspective view, showing a feeding, hot air blowing and pressing device associated with the hemming module; 
         FIG. 10  is a further enlarged-scale perspective view showing a folding device of the hemming module; 
         FIG. 11  is a further perspective view showing a working plane or surface of the hemming module; 
         FIG. 12  is yet another perspective view, on a further enlarged scale, showing in further details the feeding and pressing device included in the hemming module; 
         FIGS. 13-17  show different embodiments for applying the resilient or elastic element to the fabric material; 
       and 
         FIGS. 18 to 22  show some embodiments for performing the hemming operations in the hemming system according to the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the number references of the above mentioned figures, the hemming system according to the present invention comprises a first adhesive applying module or unit, generally indicated by the reference number  1 , for applying two adhesive materials to an elastic or resilient element and to the fabric, and a second hemming module or unit, generally indicated by the reference number  2 , for hemming said fabric at said resilient or elastic element. 
     The first adhesive applying module  1  comprises three bobbins, that is: a first bobbin  3  supporting a resilient or elastic element  6 , a second bobbin  4  supporting a first adhesive material  7  including a silicone processed protective paper layer  8 , and a third bobbin  5  supporting a second adhesive material or layer  9 , including a respective protective silicone processed paper material  10 . 
     The two first bobbins  3  and  4 , supporting said adhesive material or layer  7  and said resilient element  6 , allows the latter to be properly supplied, said adhesive material  7  and resilient element  6  being hot-coupled at a pair of pressing rollers  11  and  12  of a first adhesive applying device  13 . 
     It should be pointed out that the coupling is performed by a hot coupling operation. 
     More specifically, the adhesive web or layer  7  is so conveyed as to contact a heated plate  14 , which is heated to a variable temperature, depending on the type of the adhesive material being used, said temperature being preferably from 70° C. to 200° C. 
     Said pressing roller pair  11  and  12  provides a firm connection of said resilient fabric element  6  and adhesive material  7 , to provide an integral unit. 
     After having connected or coupled the two above mentioned materials, the protective silicone processed paper material  8  covering the adhesive layer is removed. 
     After having coated the resilient element  6 , either fully or partially, by the adhesive material layer  7 , said resilient element  6  is conveyed to a swinging roller  15 , designed for removing possible working stresses as caused by the resilient element during preliminary processing operations. 
     Then, the adhesive processed resilient element is conveyed to a programmable tensioning or pulling device  16 , which subject said resilient element to an adjustable pulling force, which in turn will prove a desired restrained force, after having applied the fabric material to be hemmed to the resilient element. 
     Then, the second adhesive strip  9  is brought to contact the adhesive processed resilient element or strip  6 ,  7 , at a hot applying device, generally indicated by the reference number  17 . 
     The applying device  17 , in particular, comprises a hot guide  18 , where a top hot air delivery device  19  is arranged. 
     The top hot air delivery device  19  comprises a swinging block  20 , including a hot air duct  21 , coupled to a top air overheating element  22 . 
     The bottom end portion of said swinging block  20  comprises a delivery spout  23 , designed for conveying a hot air flow  24  on the adhesive processed resilient assembly  6 ,  7  and on the second adhesive  9 -paper  10  assembly. 
     Thus, the overlapping material strips are suitably heated. 
     The hot guide  18 , in turn, comprises a position adjusting device for centering said hot guide  18 , said adjusting device comprising a knob or handle  31  designed for operating a centering screw element associated with said hot guide. 
     At this position, is conveyed the fabric material  27 , which is suitably heated by a bottom hot air delivery device  25 , which is in turn supplied with overheated air by a bottom air overheating device  26 . 
     Then, the fabric material  27  coupled to the adhesive material  7 , is subjected to a pressing operation, at a pair of pressing wheels  28  and  29  of a feeding and pressing device  30 . 
     As stated, the fabric material  27 , before entering the space under said wheels  28  and  29 , is heated at its bottom portion. 
     In the mentioned feeding and pressing device  30 , the fabric material  27  is coupled to the first adhesive material  7  of the mentioned resilient element  6 . 
     The second adhesive material  9  is on the other hand still covered by its silicone processed paper material  10 . 
     The two pressing wheels  28  and  29 , which practically form a pair of calendaring rollers, comprise a resilient covering layer. 
     The bottom wheel or roller  29 , on an outer portion thereof, bears a rotary cutting counter-blade  32 , cooperating with a top knife  33 , which is driven by a reciprocating movement. 
     The knife  33 , in particular, is designed for trimming away the exceeding fabric material. 
     Downstream of the disclosed apparatus, the adhesively processed resilient element  6  is cut by a cutting device  34 , including a guillotine cutting blade. 
     In this connection, it should be pointed out that the disclosed inventive system allows to perform the following operating steps. 
     P1) Applying an adhesive layer on a resilient or elastic element. 
     P2) Removing from P1 the silicone processed coating paper layer. 
     P3) Coupling a second adhesive layer on an adhesively processed resilient element, by hot guides and air. 
     P4) Applying an adhesively processed resilient element on a fabric material, by a hot air bottom heating operation, a front pre-heating operation, and a pressing between the rollers and cutting away of the exceeding fabric material. 
     P5) Cutting the resilient element by a guillotine type of cutter. 
       FIGS. 13 to 17  show some exemplary embodiments which can be made by the above disclosed hemming method and system. 
     In this connection it should be apparent that the disclosed embodiment can be subjected to several modifications and variations, in particular with respect to the operating step for applying the adhesive material to the web or strip material. 
     The hemming system according to the present invention further comprises an integrating second module or unit  2 , provided for hemming the fabric material  27  at the resilient element  6  applied by the first module  1 . 
     More specifically, the second hemming module or unit  2  comprises a feeding and pressing device  37 , arranged downstream of the folding device  38 . 
     The feeding and pressing device  37  comprises a pair of wheels  35  and  36  including a top hot air conveying duct  39 , a side hot air conveying duct  40  and a bottom hot air conveying duct  41 . 
     Said top and side hot air conveying ducts are supplied by a top air overheating device  42 , whereas the bottom hot air conveying duct  41  is supplied by a bottom air overheating device  43 . 
     The above mentioned folding device  38  comprises, on the other hand, a hemming movable guide  44 , coupled to a reference plate  45 , constituting an adjustable reference element for defining the folding depth. 
     The folding device  38  allows the preliminarily formed fabric hem to be properly folded. 
     As aforesaid, said fabric material is guided in said guides, and conveyed to said pressing rollers where it is properly “welded” or sealed. 
     The second module  2  comprises moreover a working surface or plane  46 , including cold air conveying ducts, generally indicated by the reference number  47  for conveying cooling cold air therethrough. 
     If the disclosed apparatus is deliberately switched off, then, it will provide, in a restarting step, a partial adjustable and programmable withdrawing, thereby assuring a perfect adhesion of the adhesive strip element to the fabric material, even at the stop points. 
       FIGS. 18 to 22  show some exemplary embodiments of hemming operations which can be made by using the hemming system according to the present invention, and corresponding, respectively to the resilient element applications shown in  FIGS. 13 to 17 . 
     In this connection it should be moreover pointed out that the hemming system according to the present invention allows to perform several different types of hemming operations, in addition to those which have been above shown, by way of a merely indicative example. 
     It has been found that the invention fully achieves the intended aim and objects. 
     In practicing the invention, the used materials, provided that they are compatible to the contingent requirements, can be any, depending on the needs.