Patent Publication Number: US-8123447-B2

Title: Method and apparatus for backing printed products

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(e) of provisional application No. 60/652,630, filed Feb. 14, 2005; this application also claims the priority, under 35 U.S.C. §119, of German patent application No. 10 2005 006 773.5, filed Feb. 15, 2005; the prior applications are herewith incorporated by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a method for backing printed products according and to an apparatus for backing printed products. The apparatus contains a transport and stitching line, a plurality of feeders disposed along the transport and stitching line, and a stitching station disposed downstream of the feeders along the transport and stitching line. 
     In this description, the terms signature, folded sheet assembly and brochure will be used. In this case, signature is understood to be a single-piece flat element, for example a paper sheet or cover. The signatures can be present in the feeders of the gatherer stitcher in single or multi-folded form, or unfolded in what is known as a cover feeder, in which a fold is introduced into the signature as it is deposited on the transport and stitching line gathering section. The stacks lying loosely one above another and therefore unstitched on the transport and stitching line will be designated a folded sheet assembly. As a result of stitching, the folded sheet assembly becomes a brochure, in which the signatures are firmly connected to one another. 
     Gatherer stitchers according to the invention are marketed, for example, by Brehmer Buchbindereimaschinen GmbH, Leipzig under the type designation ST400 and are configured in such a way that, until stitching and subsequent provision in the output station, the brochures are transported in the longitudinal direction of the spines of the brochures and, in the output station, are transferred by an ejector to delivery belts. The delivery belts then convey the brochures onward transversely with respect to their previous transport direction, specifically in the direction of a trimmer, in which first a front-edge cut and then a top cut and a bottom cut are made. 
     Stitched-spine brochures are typically thicker on the stitched side than on the open side. If brochures of this type are brought above one another, they tend to produce a crooked, cumbersome stack which, beginning at a certain height, has to be stabilized, for example by cross laying, banding or other techniques. If such brochures are set up vertically, they have only a narrow edge, which provides the viewer with less information about the content of the brochure than would be the case with printed products with a straight spine. It is therefore desirable to bring a stitched-spine printed product into a form which does not have these disadvantages, specifically is substantially parallelepipedal. 
     To this end, there are various approaches from the prior art. From European patent EP 1 005 984, corresponding to U.S. Pat. No. 6,363,851, it is known to produce a printed product with a rectangular spine in that, before the printed products are laid on one another, in each case two mutually spaced weakening lines are made, the mutual spacing of the weakening lines being increased in successive printed products. 
     European patent application EP 1 475 339 discloses pressing the folding edge before collation during the production of printed products. 
     European patent EP 1 479 528, corresponding to U.S. patent publication No. 2005/0008460 A1, discloses bringing a stitched printed product into a rectangular form when at a standstill by use of press rolls. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a method and apparatus and method for backing printed products which overcomes the above-mentioned disadvantages of the prior art devices and methods of this general type, with which the production of a stitched-spine printed product can be incorporated particularly well into the production of the printed product. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, a method for backing printed products. The method includes the steps of: feeding signatures to a transport and stitching line of a gatherer stitcher using a plurality of feeders; gathering the signatures on the transport and stitching line for forming a folded sheet assembly; stitching the folded sheet assembly to form a brochure along the transport and stitching line; and backing a spine of the brochure along the transport and stitching line using a pressing apparatus. 
     Accordingly, the method according to the invention is distinguished in particular by the step of backing the spine of the brochure along the transport and stitching line of a gatherer stitcher. By this “in-line” production of stitched-spine printed products with a rectangular spine, the higher processing speeds that are usual in gathering stitching technology can be achieved and, at the same time, an attractive printed product can be produced. In addition, by the backing of the spine region of the stitched product, the stability of the product is increased considerably, which has a positive effect on the handling of the product by downstream processing devices, such as cross layers, packaging machines, insertion machines, strapping devices, film-wrapping devices and so on. In addition the products backed in this way are flatter, so that they stick up or gape less. As a result of the good planarity of the product, this is particularly advantageous in the case of products in which a stack has to be produced, for example in a cross layer. 
     In an advantageous refinement of the method according to the invention, the method contains the additional step of the thickness inspection/thickness measurement of the collated brochure on the gathering chain. As a result, first, conclusions can be drawn as to whether the brochure is complete, but also second, from the thickness measurement, other parameters for the optimization of the method can be derived, for example the setting of the pressing elements of the pressing apparatus as a function of the thickness of the brochure. As a result, the considerable forces arising during the backing are matched to the respective product in such a way that, first, the forces are sufficiently high to achieve the desired deformation of the spine of the brochure but, second, the forces are sufficiently low that damaging the brochure by pressing forces set excessively high is reduced. 
     In a further advantageous refinement of the method according to the invention, the measured values from the thickness inspection are additionally used to introduce two mutually parallel creases spaced apart from each other into a cover, which is supplied to the transport and stitching line by a folded cover sheet feeder, the distance between these creases corresponding exactly to the thickness of the folded sheet assembly. This leads to an esthetic visual appearance of the finished printed product. 
     Other features which are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a method and apparatus for backing printed products, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic, perspective simplified view of an embodiment of a gatherer stitcher according to the invention for backing printed products; 
         FIG. 2A  is a diagrammatic, plan view of details of a first embodiment of a pressing apparatus according to the invention; 
         FIG. 2B  is a side-elavational view of details of the first embodiment of the pressing apparatus according to the is invention; 
         FIG. 3  is a diagrammatic, cross-sectional view through the first embodiment of the pressing apparatus according to the invention in a region of the backing of the spine of the brochure; 
         FIG. 4A  is diagrammatic, plan view of details of a second embodiment of the pressing apparatus according to the invention; 
         FIG. 4B  is a diagrammatic, side-elevational view of details of the second embodiment of the pressing apparatus according to the invention; and 
         FIG. 5  is a diagrammatic, cross-sectional view of the second embodiment according to  FIGS. 4A ,  4 B of the pressing apparatus according to the invention in the region of the backing of the spine of the brochure. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown a gatherer stitcher which contains three folded sheet feeders  10 ,  12 ,  14 , which each transfer a signature  16 ,  18 ,  20  to a transport and stitching line  22 . The signatures  16 ,  18 ,  20  placed under and over one another in this way together form a folded sheet assembly  30 , which is transported in a transport direction according to arrow P along a transport and stitching line  22 , which extends along the folded sheet feeder  10 ,  12 ,  14  and beyond a stitching station  24  as far as an output station  29  having delivery belts  29 . 1 . By use of the delivery belts  29 . 1 , a stitched-spine and backed brochure  32  is transported in a direction of the arrow identified by the letter T to a following non-illustrated trimmer, in order to be trimmed on the three open sides. 
     Between the folded sheet feeders  10 ,  12 ,  14  and the stitching station  24 , a folded cover sheet feeder  50  is shown by way of example in this embodiment, which initially folds a cover  51  and then deposits it on the folded sheet assembly  30  on the transport and stitching line  22 . In a further embodiment, the folded cover sheet feeder  50  has a known creasing device, with which creases (weakening lines) can be introduced into the cover  51 . In this case, in a particularly advantageous embodiment, two creases are introduced into the cover  51 , the spacing of which from one another corresponds exactly to the thickness of the folded sheet assembly  30 , the creases therefore in the backed state coinciding exactly with the outer edges of the spine  31  of the brochure  32 . Here, it is to be noted that the folded cover sheet feeder  50  does not necessarily fold the cover  51  at the weakening lines but instead in the middle of the sheet for the purpose of simplified stitching. In this case, this fold is advantageously a plow fold having a large radius, so that the folded line of the cover  51  does not stand out in the end product. 
     Between the last feeders  10 ,  12 ,  14  or the folded cover sheet feeder  50  and the stitching station  24 , a thickness inspection with measuring device  33  is provided, in which the thickness of the folded sheet assemblies  30  to be stitched is determined. 
     The stitching station  24  in the present exemplary embodiment contains two stitching heads  26  and a respective crimper, which cannot be seen in the figures, assigned to the same which bends over wire staples  27  stuck by the stitching heads  26  into the folded sheet assemblies  30  to be stitched, specifically the legs of the wire staples  27  which have penetrated the folded sheet assemblies  30 . 
     Following that, the pressing apparatus  40  according to the invention is disposed, which brings the spines of the gathered brochures  32  into a substantially rectangular form. 
     In  FIGS. 2A-3 , details of the pressing apparatus  40  according to the invention are shown only schematically. Drives, control elements, housings and other elements which are not essential to the invention and are left to the discretion of those skilled in the art have been left out for the purpose of improved clarity. 
     The pressing apparatus  40  illustrated in  FIGS. 2A ,  2 B and  3  has a plurality of pressing elements  41 ,  42  above the transport and stitching line  22 , namely an upper press roller  41  and two lateral press rollers  42 , which are disposed on either side of the transport and stitching line  22 , substantially in the region of the upper press roller  41 , in particular somewhat upstream of the upper press roller  41 . 
     To this end, the press rollers  42  have an appropriate step, so as not to block the upper press roller  41  and, at the same time, to preserve sufficient stability for the lateral press rollers  42 , see  FIG. 3 . The shaping of the spine  31  is achieved substantially by the upper press roller  41  interacting with the lateral press rollers  42 , and is carried out in a region in which the brochure  32  is still gripped firmly between the two lateral press rollers  42 . These hold the upper edge of the brochure  32  somewhat underneath the stitching, after which the upper press roller  41  rolls the previously pointed upper edge of the brochure  32  flat, so that a rectangular form of the spine  31  is achieved. The lateral press rollers  42  and the upper press roller  41  are advantageously incorporated in a housing  45  of the pressing apparatus  40  in such a way that their position in relation to one another, in particular the spacing from one another along the transport direction P can be set variably. 
     A front hold-down roller  43  is placed upstream of the pressing elements  41 ,  42 , and a rear hold-down roller  44  is placed downstream. The upstream hold-down roller  43  is used first to center the stitched brochure  32  as it runs in. However, both hold-down rollers  43 ,  44  are also used in particular to press the brochure  32  securely onto a dividing plate  47  as the brochure is backed by the pressing elements  41 ,  42 , in order to prevent slipping during the backing and in this way to ensure the formation of the desired rectangular spine  31  of the brochure  32 . In an advantageous refinement, the hold-down rollers  43 ,  44  are assigned running rollers located at the bottom in the region of the dividing plate  47 , so that undesired marking of the signature resting on the dividing plate  47  as a result of the pressure is prevented. In addition, one or both of the hold-down rollers  43 ,  44  can have a profile for improved functionality, for example a circumferential groove, in order to improve the centering. 
     The rollers  41 ,  42 ,  43 ,  44  move with a circumferential speed which corresponds substantially to the transport speed of the brochure  32  along the transport and stitching line  22 . In an advantageous embodiment, at least one of the rollers  41 ,  42 ,  43 ,  44  is configured to be driven, advantageously at least the press rollers  41 ,  42 . The rollers  41 ,  42 ,  43 ,  44  are in each case fixed in a sprung manner to the housing  45  of the pressing apparatus  40 . As a result, springing out in the event of a stoppage of the gatherer stitcher  5  is made possible. 
     The brochures  32 , which are transported on saddle plates  23  by the transport and stitching line  22 , are built up differently as a result of their possible different thickness, depending on the number and thickness of the collected signatures  16 ,  18 ,  20  and of the cover  51 . This can be different from brochure  32  to brochure  32  in what is known as “selective binding” or “personalized binding”. Therefore, all the adaptations of the thickness must be carried out upward from the ridge of the transport and stitching line  22  or the dividing plate  47 , for example with respect to the lateral press rollers  42  and, in addition, also on both sides laterally with respect to the dividing plate  47 , since the brochure is built up both in the height of the saddle and also in relation to its flanks, on which the lateral press rollers are disposed. Therefore, in each case position adjusting devices  41 . 1 ,  42 . 1 ,  43 . 1 ,  44 . 1  are provided, by which the position of the respective rollers  41 ,  42 ,  43 ,  44  with respect to the transport and stitching line  22  can be set. In this case, the position adjusting devices  41 . 1 ,  42 . 1 ,  43 . 1 ,  44 . 1 , are for example, simple knurled wheels. Alternatively, these can also be actuating elements, in particular including those which are set automatically by a higher-order controller to the desired stipulated position, for example on the basis of information with regard to the thickness of the folded sheet assembly  30  which has been determined by the thickness inspection with the measuring device  33 . Alternatively, however, automatic adjustment in response to information which is input by a user is also conceivable. The position adjusting devices  41 . 1 ,  42 . 1 ,  43 . 1 ,  44 . 1  can be used at the same time for setting the pressing force of the rollers  41 ,  42 ,  43 ,  44 . 
     In addition to the position adjusting devices  41 . 1 ,  42 . 1 ,  43 . 1 ,  44 . 1  of the rollers  41 ,  42 ,  43 ,  44 , non-illustrated position adjusting devices are provided, with which the complete pressing apparatus  40  (without dividing plate  47 , saddle plates  23  and transport and stitching line  22 ) can be raised and/or lowered, depending on the embodiment, likewise under automatic control in response to information which is determined by the thickness inspection with measuring device  33  or is predefined by an operator or a higher-order controller. All the actuating elements can be, for example, motors, pneumatic cylinders or solenoids. The adaptation to respective brochure thickness is preferably made during continuous operation. 
     A driver  22 . 1  on the transport and stitching line  22  transports the brochure  32  along the transport direction P. The driver  22 . 1  is disposed on the transport and stitching line  22  in such a way that, in the region of the pressing apparatus  40 , it runs underneath the lateral press rollers  42 . In the region of the pressing apparatus  40 , the brochure  32  lies astride the saddle plates  23 . In the region of the pressing apparatus  40 , the saddle plates  23  are lowered. In the upper region, the brochure  32  is supported by the dividing plate  47  under the ridge. In the region of the lateral press rollers  42 , this dividing plate  47  has a cut-out  48 , which is provided with an entry chamfer  49 , in order to guide the backed part of the spine  31  of the brochure  32  onto the dividing plate  47  again without disruption. 
     As a result, by using the pressing apparatus  40 , brochures  32  with a high-quality appearance can be produced which, as a result of the profiled angular spine  31 , have a high inherent strength and consequently can be stood up better, for example in a bookshelf. In addition, possible labeling of the spine  31  is legible and therefore, for example, identification of the brochure  32  in the bookshelf is possible. In addition, with regard to the ability of the brochures  32  to be stacked, the printed products produced with the apparatus according to the invention in accordance with the method according to the invention are improved as a result of their reduced gaping behavior. 
     In a further embodiment, as illustrated in  FIGS. 4A ,  4 B and  5 , the dividing plate  47  is moved from a stitching position H by a lifting travel h into a backing position A via a coupler mechanism  52 . The product is thus lifted off the transport and stitching line  22  by a lifting apparatus.