Abstract:
A gatherer-stitcher used for gathering various folded sheets is additionally equipped with one or a plurality of devices for applying adhesive, so that the gathered sheets can be bonded to one another directly on the gatherer-stitcher.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention is directed to a device for joining folded products gathered on a raceway such as a gatherer chain conveyor, in particular folded sheets or thread-sealed folded sheets.  
           [0002]    Gatherer-stitchers are paper-processing machines which manufacture a product from a plurality of folded sheets, the individual folded sheets being so joined to one another that a finished product results. The manufactured end products are multi-page printed products, such as magazines, brochures, or the like. Gatherer-stitchers of this kind usually include one or more folded-sheet feeders, which feed the individual folded sheets to a raceway, upon which the various folded sheets are collected into groups to form the desired end product. The groups hanging on the raceway are usually fed to a stapling station having one or more stapling heads. At the stapling station, the folded products are joined at their spines by wire staples. Once stapled together, the groups of folded sheets are conveyed to a trimmer, which cuts the edges of the stapled products and then feeds them to a delivery unit.  
           [0003]    The folded sheets, provided either laying or standing on their spines in the folded-sheet feeders, are separated, opened, and placed on the raceway. This process is repeated with each folded-sheet feeder until the desired number of folded products hangs one over another, as a group, on the raceway and is situated true-to-register thereon. The last feeder then feeds a folded cover sheet to the group. Alternatively, a sheet can be folded while being conveyed on the raceway by a so-called cover folder feeder. The cover is placed in this manner over the group of folded products.  
           [0004]    To join the thus gathered folded products, the cover is conveyed, together with the remaining folded products, to a stapling station, where one or more staples are stuck through the spines of the folded products, [piercing the same], thereby joining the folded products, as well as the cover, to one another. A method of this kind is known, for example, from German Patent DE 197 38 929.  
           [0005]    Although staples securely fasten folded products to one another, the need can arise to join the folded products to one another in some other way, and not by using wire staples. This is particularly the case when the end product to be manufactured is intended to be used for the most part by children or by small children, where eliminating the danger of injury is paramount. Coloring books made for children, as well as assembly or operating instructions for children&#39;s toys, which are stapled on the inside by wire staples, for example, can easily cause injury to children&#39;s hands.  
         SUMMARY OF THE INVENTION  
         [0006]    An object of the present invention is, therefore, to provide a device and a method which will make it possible to permanently join folded products to one another on a gatherer-stitcher and to, nevertheless, avoid the danger of injury by a wire stapling.  
           [0007]    The present invention provides a device for joining folded products ( 20   a,    20   b ) gathered on a gatherer-stitcher, in particular folded sheets or thread-sealed folded sheets, which are transported on a conveying device ( 10 ) of the gatherer-stitcher, hanging, with their spines ( 32 ) directed upwards, wherein the gatherer-stitcher has a station ( 24 ) for applying glue to the spines ( 32 ) of the folded products hanging on the gatherer-stitcher.  
           [0008]    The present invention also provides a method for joining folded products ( 20   a ,  20   b ) gathered on a gatherer-stitcher, in particular folded sheets or thread-sealed folded sheets, at least one folded product ( 20   a ,  20   b ) being conveyed from a folded-sheet feeder of a raceway of a gatherer-stitcher, wherein adhesive is applied along the spine ( 32 ) of a folded product hanging on the raceway ( 10 ), and the folded product provided with adhesive is subsequently covered with an additional folded product ( 22 ,  20   b ).  
           [0009]    It is generally a distinction of the device according to the present invention to provide at least one additional station at the gatherer-stitcher. The additional station makes it possible to apply adhesive or glue to the spine of a folded product situated at the top of a group of folded products, or to an individual folded product, thereby enabling a cover page to be placed thereon and to be permanently joined to the remaining folded product(s) without using wire staples in the process. It is especially advantageous in this context when the folded products, constituted as a group, are already joined to one another in some other fashion, without the cover. In particular, the folded products may be thread-sealed folded products that have been thermoplastically joined by a thread in a previous sequence of operation.  
           [0010]    The device according to the present invention, therefore, has the advantage of facilitating the production of printed products, which are permanently joined to one another, the need being completely eliminated for wire staples which always hold the danger of injury. A further benefit is that wire staples no longer have to be removed, a step which requires considerable effort, so that the process of recycling the paper material is substantially simplified.  
           [0011]    A further benefit of the device according to the present invention is derived from the fact that the gluing station can be installed as an additional element on already existing gatherer-stitchers, making it optional to either implement the classic stapling using wire staples and/or a stapleless joining of the folded products using the gluing station. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    Further benefits and advantageous further refinements constitute the subject matter of the figures and of their descriptions in the following, the figures not being drawn true to scale the sake of clarity.  
         [0013]    [0013]FIG. 1 shows the schematic representation of a gatherer-stitcher; and  
         [0014]    [0014]FIG. 2 shows schematically, a device according to the present invention in the area of the gluing station. 
     
    
     DETAILED DESCRIPTION  
       [0015]    [0015]FIG. 1 schematically illustrates a conveyor system of a gatherer-stitcher in accordance with the present invention, which includes a gluing station. This conveyor system is usually designed as a raceway  10 . From stacks  12 ,  14  of folded products present in each of the folded-sheet feeders, individual folded products  20   a ,  20   b  are transported by a plurality of folded-sheet feeders (not shown for the sake of clarity in FIG. 1) onto raceway  10 , on which they come to rest, hanging one over another. Groups of folded products  16 ,  18  are formed in this manner and are transported on the raceway in arrow direction A. As shown in FIG. 1, the stacks of folded products can be fed to the raceway as stacks  12  resting on their spine or as stacks  14  resting on their surfaces. Folded products  20   a ,  20   b  are, for example, folded sheets or signatures, or folded signatures or sheets that have been joined to one another in a previous work step. So-called thread-sealing comes under consideration, in particular, as a way to join the folded products beforehand.  
         [0016]    Each group of signatures  16  is conveyed on raceway  10  in arrow direction A and, in the process, arrives at a device  25 , which can be used to apply an adhesive, such as a glue, to spine  32  of topmost folded product  20   a  of a group  16 . Once the adhesive is applied, the group is moved along in arrow direction A, and can be led to another station  11 , where another folded product  20   b  is placed over topmost folded product  20   a.  A pressure roller  27  is used to permanently join folded product  20   b  to the remaining folded products, particularly to folded product  20   a.    
         [0017]    Optimally, a second gluing station  24  can be provided which is used at this point in similar fashion to apply glue to the now topmost folded product  20   b.  Group  18  is further transported along conveying route A to arrive at a further station  26 .  
         [0018]    Here, a cover page  22  is placed over group  18 , on glue-covered spine  32  (FIG. 2) of signature  20   b.  Cover page  22  is then pressed by pressure roller  29 .  
         [0019]    Provided that all folded products of a group  16 ,  18  are already joined to one another, application of adhesive at station  24  enables one cover page to be completely joined to the remaining folded products, without having to staple the folded products using wire staples.  
         [0020]    Once all the folded products, including cover page  22 , are joined together, the thus completed, multipage printed product, for example a magazine, operating instructions, a coloring book or the like, can be conveyed to further handling or processing stations, such as to a trimming station.  
         [0021]    Although the present invention manages completely without stapling to join the folded products, one can conceive of the gatherer-stitcher having a station for inserting staples, which can be used alternatively to glue application station  24 , so that, depending on the end product to be produced, the gatherer-stitcher is able to produce folded products that are joined to one another by stapling or by bonding.  
         [0022]    [0022]FIG. 2 schematically depicts a device in accordance with the present invention in the vicinity of gluing station  24 . Topmost folded product  20   b  of group  18  is transported on a raceway  10  by underlying folded products  16  (FIG. 1) in transport direction A, the folded products being aligned by a transport finger  28  mounted on raceway  10 . A glue application head  30  applies glue to the spine of topmost folded product  20   b,  while the raceway, together with the folded products, continues to move underneath glue application heads  30  in arrow direction A. A control unit  36 , a gluing unit  37 , and a sensor  34  control the quantity of adhesive and the instant of its application. For this purpose, glue application head  30  is connected to lines  38  and  38 . Line  39  carries the adhesive, and lines  38  transmit the control pulses and supply the compressed air for the adhesive application. Sensor  34  detects the front edge of the folded product and transmits a signal via line  41  for further processing to control unit  36 , which controls the length of the glue line to be applied and the interval in which no glue is applied. A vertically adjustable hold-down device  40  is provided for holding down folded product  20   b  during glue application.  
         [0023]    Following the application of glue to spine  32 , the group of folded products  18  (FIG. 1), as already described in FIG. 1, is conveyed to a station  26 , where a cover is put on the adhesive to join all folded products to one another. It is, therefore, advantageous to provide the gluing station as the last station, immediately before the location where the cover is placed on the raceway.  
         [0024]    Once the cover is placed on the adhesive, the glued product is preferably conveyed to a pressure-applying station  29 , where cover  22  is pressed onto the remaining folded products  20   a ,  20   b,    16 . The pressure-applying station, preferably a spring-loaded forming roller, presses the folded sheets together in such a way that the adhesive join is fixed and a precision bonding results.  
         [0025]    A further benefit is derived from the fact that the device according to the present invention can be used even when only one of the folded-sheet feeders, usually provided in a plurality, is equipped and is in operation, and when folded products, already joined to one another, are present in these folded-sheet feeders. These can be folded products that have been joined by thread-sealing, for example. As described, they are conveyed to the raceway. The adhesive is then applied to the spine of the interconnected folded products and, in a further process step, covered by a cover page and permanently joined by the adhesive to the thread-sealed folded products. In this manner, an end product can be produced, whose inside pages are joined together using the thread-sealing technique or other methods, and whose cover page is fastened by adhesive to the thread-sealed folded products. Therefore, from the outside, it is not evident what kind of joining method is used to make the individual folded products adhere to one another. Moreover, this end product has no pointed or sharp wire staples whatsoever, so that it also meets more stringent safety requirements.  
         [0026]    Another advantageous specific embodiment of the device according to the present invention provides for multiple gluing stations  24 , and optionally for multiple pressure-applying stations  27 , for example, for one gluing station  24  to follow every or every few folded-sheet feeders. This multiplicity of gluing stations now makes it possible to apply a glue line to the spine of the folded product, once it is placed on the raceway, this glue line then being suited, in turn, to bond the next folded product to be placed, to the folded products already located on the raceway. Thus, an end product can be manufactured which is entirely composed of folded products that are joined to one another by glue.  
         [0027]    All adhesives suited for joining folded products can be used, such as glue, in particular, however, dispersion glue, hotmelt glue, PUR (polyurethane reactive) adhesives or fugitive glue.  
       Reference Symbol List  
       [0028]    [0028] 10  raceway  
         [0029]    [0029] 11  station  
         [0030]    [0030] 12 ,  14  stacks of folded products  
         [0031]    [0031] 16 ,  18  groups of folded products  
         [0032]    [0032] 20   a ,  20   b  folded products  
         [0033]    [0033] 22  cover page  
         [0034]    [0034] 24  gluing station  
         [0035]    [0035] 26  station  
         [0036]    [0036] 27  pressure-applying station  
         [0037]    [0037] 28  transport finger  
         [0038]    [0038] 29  pressure-applying station  
         [0039]    [0039] 30  glue-application head  
         [0040]    [0040] 32  spine  
         [0041]    [0041] 34  sensor  
         [0042]    [0042] 36  control unit  
         [0043]    [0043] 37  gluing device  
         [0044]    [0044] 38  lines  
         [0045]    [0045] 39  line  
         [0046]    [0046] 40  hold-down device  
         [0047]    [0047] 41  line