Abstract:
An apparatus for manufacturing multilayer articles, comprising a first feeder for feeding a band made of textile material, a punching device arranged downstream of the first feeder to form slots in the band, a second feeder for feeding a strip of textile material arranged downstream of the punching device to arrange the strip so as to cover the slots, a sewing apparatus arranged downstream of the second feeder to fix the strip onto the band so as to cover the slots and provide a multilayer article, and a traction assembly arranged downstream of the sewing apparatus to actuate the advancement of the article through the sewing apparatus toward a collection unit.

Description:
[0001]    The present invention relates to an apparatus for manufacturing multilayer articles made of textile material, particularly but not exclusively the perimetric bands of mattresses provided with ventilation slots. In the continuation of the description, the definition of “textile material” is understood to reference materials which can be subjected to quilting processes, such as fabrics, non-woven fabrics, felt, expanded synthetic materials, such as polyurethane foams and the like. 
       BACKGROUND OF THE INVENTION 
       [0002]    As is known, mattresses comprise an upper multilayer sheet and a lower sheet, the edges of which are mutually connected by a perimetric band, forming the case of the mattress, in which an insert is accommodated which is constituted by a cage of cylindrical spiral springs or by a panel of expanded plastic material which has elastic properties. 
         [0003]    To allow internal ventilation of the mattress, the perimetric band of the case is provided with slots. 
         [0004]    European Patent Application No. 07114821.7 filed Aug. 23, 2007 in the name of this same Applicant discloses a band for the perimetric closure of mattresses in which a strip of breathable textile material is arranged so as to cover the ventilation slots. 
       SUMMARY OF THE INVENTION 
       [0005]    The aim of the present invention is to provide an apparatus which allows to apply, by means of stitched seams, a strip onto a band which is aligned with it. 
         [0006]    Within this aim, an object of the present invention is to provide an apparatus which allows to provide ventilation slots within the band and in alignment with said band and to apply, by means of stitched seams, a breathable textile strip to cover the ventilation slots. 
         [0007]    Another object of the present invention is to provide an apparatus which allows to prepare continuously or intermittently a multilayer band provided with ventilation slots and to associate continuously or intermittently with said band, by means of stitched seams, a strip for covering the slots. 
         [0008]    This aim and these and other objects which will become better apparent hereinafter are achieved with an apparatus for manufacturing multilayer articles, characterized in that it comprises first means for feeding a band made of textile material, a punching device which is arranged downstream of said first feeder means and is adapted to form slots in said band, second means for feeding a strip of textile material which are arranged downstream of said punching device and are adapted to arrange said strip so as to cover said slots, a sewing apparatus which is arranged downstream of said second means and is adapted to fix, by means of stitched seams, said strip onto said band so as to cover said slots, so as to provide a multilayer article, and a traction assembly which is arranged downstream of said sewing apparatus in order to actuate the advancement of said article through said sewing apparatus toward a collection unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein: 
           [0010]      FIG. 1  is a perspective view of an apparatus according to the invention; 
           [0011]      FIG. 2  is a perspective view of the apparatus, taken from the opposite side with respect to  FIG. 1 ; 
           [0012]      FIG. 3  is a side view of the apparatus; 
           [0013]      FIG. 4  is a plan view of the apparatus of  FIGS. 1 and 2 ; 
           [0014]      FIG. 5  is a sectional view, taken along the plane A-A of  FIG. 3 ; 
           [0015]      FIG. 6  is a sectional view, taken along the plane B-B of  FIG. 4 ; 
           [0016]      FIG. 7  is a sectional view, taken along the plane D-D of  FIG. 4 ; 
           [0017]      FIG. 8  is a sectional view, taken along the plane E-E of  FIG. 4 ; 
           [0018]      FIG. 9  is a perspective view of the traction assembly; 
           [0019]      FIG. 10  is a front view of the assembly of  FIG. 9 ; 
           [0020]      FIG. 11  is a side view of the assembly of  FIG. 9 ; 
           [0021]      FIG. 12  is a sectional view, taken along the plane C-C of  FIG. 10 ; 
           [0022]      FIG. 13  is a perspective view of the region where the strip is applied to the band. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    With reference to  FIGS. 1 ,  2 ,  3  and  4 , the apparatus is composed of a main frame, generally designated by the reference numeral  1 , upstream and downstream of which, with respect to the advancements direction F of the band and of the strip which co-operate to form the final article, respective brackets  2 ,  3  protrude. 
         [0024]    The bracket  2  supports three reels  4 ,  5 ,  6 , which are mounted so that they can rotate on respective shafts  7 ,  8 ,  9  and protrude in a cantilever fashion from the bracket  2 . Two ribbon-like fabrics  10 ,  11  are wound around the reels  4 ,  6 , whereas an intermediate insert  12  is wound onto the intermediate reel  5  and is constituted for example by a tape made of flexible expanded plastic material ( FIG. 3 ). The two fabrics  10 ,  11  and the insert  12  are unwound in the feeding direction F from the respective reels  4 - 6  and are conveyed between a pair of parallel rollers  13 ,  14 , which are mounted so that they can rotate on a secondary frame  15  which is fixed to the main frame  1 . Conveniently, tensioning rollers  16  act on the fabrics  10 ,  11  in order to maintain the correct tension. 
         [0025]    The fabrics  10 ,  11  and the insert  12  have the same width, so that at the output from the rollers  13 ,  14  they form a single three-layer tape which is referenced hereinafter, for the sake of convenience in description, as the band  17 . The band  17  is then guided through a punching device, generally designated by the reference numeral  18  and shown in greater detail in  FIGS. 5 and 6 . 
         [0026]    The punching device  18  is composed of a pair of mutually parallel and superimposed rollers  19 ,  20 , which are supported so that they can rotate in two side walls  21 ,  22  which rise from the main frame  1 . The rollers  19 ,  20  are provided with pivots which pass through the side wall  22  and on which a gear is keyed which is composed of a pair of sprockets  23 ,  24  which have the same diameter and mesh together. 
         [0027]    A pulley  25  is also keyed onto the same pivot onto which the lower sprocket  24  is keyed, and a transmission belt  26  is wound onto said pulley and, by means of an additional belt  27 , receives motion from a motor  29  which is coupled by means of a flange to the sewing machine  36  described below. 
         [0028]    The belt  27  is closed in a loop on a pulley  28 , which is keyed to the output shaft of the motor  29 , and on a pulley  28   a , which is keyed to an auxiliary shaft on which the pulley  27   a  for guiding the belt  26  is keyed. 
         [0029]    By virtue of the gear system  23 ,  24 , the rollers  19 ,  20  contrarotate with respect to each other so that the direction of rotation is F in the point of tangency. 
         [0030]    The rollers  19 ,  20  have such a diameter as to define, in their point of tangency, a slit which is adapted to keep the strips  10 ,  11  in contact against the upper and lower faces of the intermediate insert  12 , optionally applying adequate compression to the latter. 
         [0031]    Two punches  30 ,  31  are arranged diametrically within the rollers  19 ,  20 , in a central position thereof, and have respective ends which mutually cooperate so as to provide a sort of punching blade which is adapted to form slots  32  in the band  17  which is guided between the rollers. For this purpose, one end of a punch forms, as shown more clearly in  FIG. 6 , an annular blade which, along the arc of the rotation in which the punches are mutually opposite, engages a complementary blade which is formed at the end of the other punch, cutting through the band at each turn of the rollers and forming slots  32  which are equidistant along a central line of the band  17 . 
         [0032]    Downstream of the punching device  18  there are two additional rollers  33 ,  34 , which can rotate within a secondary supporting frame  35  which is fixed to the main frame  1 . The rollers  33 ,  34  are designed to divert the band  16  toward a sewing apparatus  36 , upstream of which there is an interposed additional pair of rollers  37 ,  38  which are supported so that they can rotate within a secondary frame  42  and are designed to associate with the band  17  a strip  39  made of breathable textile material. 
         [0033]    The strip  39  is taken from a reel  40 , which can rotate on a shaft  41  which is supported at the ends of two angled arms which extend upward from the sides of the secondary frame  42  ( FIG. 3 ) for supporting the rollers  37 ,  38 . 
         [0034]    The sewing machine  36  ( FIGS. 7 ,  8 ) has a traditional structure and comprises a camshaft  43 , which is supported so that it can rotate within the side walls of a portal-shaped framework  43   a , which is fixed to the frame  1  downstream of the sewing machine. The camshaft  43  is connected by a belt  44  to the same motor  29  that drives the belt  27 , which by means of the other belt  26  actuates the punching device  18 . 
         [0035]    The camshaft  43 , by means of a pair of linkages  45 , imparts a reciprocating motion to the bar  46  which carries the sewing needles  47  which are functionally associated with the respective crochets  48 . 
         [0036]    As shown more clearly in  FIG. 13 , in the described example there is a series of needles  47 , of which the two central ones  47   a  fix the lateral edges of the strip  39  onto the central region of the band  17 , so as to cover the slots  32 , while the remaining needles continue to join together the fabrics  10 ,  11  and the insert  12  along the lateral regions with respect to the band  32 . 
         [0037]    The described apparatus further comprises a traction assembly, which is generally designated by the reference numeral  49  and is arranged downstream of the sewing machine  36  ( FIGS. 9-12 ). 
         [0038]    The traction assembly  49  is designed to grip the band  17  that abandons the sewing apparatus or machine  36  already provided with the strip  39  and to impart an intermittent advancement movement to the band  17 . 
         [0039]    The assembly  49  comprises a box-like body which has two side walls  50 ,  51 , which are mutually connected by a cross-member  52  for fixing below the plane of the frame  1 . The side walls  50 ,  51  support a shaft  53  whose opposite ends protrude outside the side walls. A pulley  54  is keyed onto one end and, by means of a belt  55 , receives motion from the motor  29 ; an eccentric element  56  is keyed onto the other end. 
         [0040]    A bracket  57  is externally rigidly coupled to the side wall  50  and together with said side wall supports a shaft  58  which is parallel to the shaft  53 . 
         [0041]    A pulley  59  and a bush  60  provided with a radial arm  61  which extends upward ( FIG. 12 ) are keyed onto the shaft  58 . The arm  61  is connected to the eccentric element  56  by a tension element  62  of adjustable length. A driving belt  63  is wound around the pulley  59  and is closed in a loop around an additional pulley  64 , which is coupled rotatably, together with a second pulley  65  having a smaller diameter, to a pivot  66  which is supported rotatably on parts of the box-like body which are not shown in the drawing but can be deduced easily. 
         [0042]    By means of a narrow belt  67 , the pulley  65  transmits motion to a pulley  68  which is keyed onto a pivot  69  which extends axially from one end of a roller  70  which is supported rotatably within the body of the assembly  49  and has a knurled external surface. 
         [0043]    A first gear  71  is fixed rotationally to the pivot  70 , to the side of the pulley  68 , and a second gear  72  meshes therewith and is associated with a roller  73  which is parallel to the roller  70 . In  FIG. 9 , the gears  71 ,  72  are shown mutually disengaged for the sake of clarity of the drawing. 
         [0044]    To allow the intermittent advancement motion of the band  16  only in the direction F, a one-way joint or freewheel is incorporated into the bush  60  and allows to use the oscillation of the arm  61  only in the direction F. 
         [0045]    It should be noted that the traction assembly  49  is synchronized with the sewing machine  36  so that the advancement movements of the band  17  produced by the rollers  70 ,  73  occur when the bar  46  of the needles is raised and therefore the needles  47  are disengaged from the band  17 . 
         [0046]    The described apparatus is completed by a sliding surface  74  which conveys the band  17  toward a takeup reel  75 , which is mounted on the bracket  3  and actuated by a motor  76 . 
         [0047]    Although the operation of the apparatus can be deduced already from the above description, it occurs as follows. 
         [0048]    The fabrics  10 ,  11  and  12 , once they have been joined by the rollers  13 ,  14 , form a band  17  which is punched inside the device  18 . 
         [0049]    After passing beyond the device  18 , the band  17  passes through the sewing machine  36 , where the strip  39  is joined so as to cover the slots  32 . 
         [0050]    Conveniently, as shown in  FIG. 13 , upstream of the needles  47  there is a tucking plate  77  which tucks under the strip  39  the lateral edges thereof, so as to ensure higher strength of the stitched seams. 
         [0051]    Finally, the band thus completed is moved by the rollers  70 ,  74  of the traction assembly  49  with an intermittent advancement in the manner described above and is wound onto the takeup reel  75 . 
         [0052]    The described apparatus therefore achieves the intended aim and objects. In particular, it is noted that any differences in the advancement of the band  17  due to the continuous traction performed by the punching device  18 , with respect to the intermittent traction performed by the traction assembly  49 , are absorbed effectively by the elasticity of the textile material of which the band  17  is made. In any case, the punching device can be controlled kinematically by the traction assembly in order to ensure constant advancement of the band  17 . 
         [0053]    The described invention is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. 
         [0054]    The disclosures in Italian Patent Application No. BO2007A000061 from which this application claims priority are incorporated herein by reference.