Abstract:
A method and apparatus for the processing of print products. The method may include conveying individually the print products with a feeding device along a feeding section, transferring individually the print products from the feeding section to a further processing section, and generating control signals from a control unit. The control signals may correspond to further treatment of each individual print product and to the transfer of a print product to the further processing section such that it can be processed further. The apparatus may include a feeding device configured to convey the print products individually along a feeding section, a transfer device configured to individually transfer the print products from the feeding device to a further processing device, and a control unit configured to generate control signals to control the transfer of the print products from the feeding device to the further processing device.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of European Patent Application No. 09405075.4-1256, filed on May 1, 2009. This application also claims the priority benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/175,096, filed on May 4, 2009. The subject matter of each of the foregoing applications is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to a method for the processing of print products, wherein the print products are supplied individually along a feeding section and are transferred individually to a further processing section to be processed further. The invention also relates to an apparatus for realizing methods of this type. 
     2. Related Art 
     When processing print products, these products are imprinted with the aid of a rotary press, operating at a printing speed that is normally predetermined, and are then subjected to further processing operations, such as, for example, folding, cutting and trimming, stitching, inserting or the like. The processing speeds of the individual further processing operations can vary. With a continuous production, also called an “online production,” the total production speed must be adjusted to the further processing speed of the further processing operation with the slowest speed, resulting in a reduction of the productivity on the whole. 
     To avoid these problems, it has already been proposed that, following the individual further processing steps, the print products be stored temporarily in buffer systems such as, for example, by winding them around a winding system. Then, at an appropriate time, those print products temporarily stored in the buffer system may be unwound from the winding system and subjected to the further processing steps. As a rule this is tied to considerable expenditure since it requires on the one hand that a buffer system be made available and, on the other hand, that additional means be provided for the standard buffer systems, e.g. winding systems or the like, for the further processing of the print products in the intermediate storage. Corresponding methods are described, for example, in the documents EP 0 272 398 A1, WO 94/02398 and CH 664 138 A5 as well as in the CH 655 076 A5, each of which is incorporated herein by reference. 
     In view of the problems described in connection with the use of buffer systems, it has been proposed that the flow of print products, reaching a slow-operating further processing device, if applicable be divided and conveyed to several further processing devices. In that case, only each second, third or fourth print product, for example, of the incoming product flow is supplied to a specific further processing device, so that even with a particularly high feeding speed, a slow further processing with two, three or more processing systems is possible without having to reduce the production speed on the whole. In the process, the flow of supplied print products is divided according to fixed division ratios into two, three or more partial flows. It has turned out that a high production speed can be achieved with this method, to be sure, but that the capacity of the further processing devices frequently is not utilized completely. 
     When using known methods for dividing the flow of supplied print products, the insufficient use of the capacity of further processing devices results from the fact that the flows are divided according to fixed ratios which are determined by the number of available further processing devices. The speed of the further processing device is consequently tied directly to the feeding speed and cannot be influenced further. 
     In view of the above described problems, it is an object of the present invention to provide methods for the processing of print products which allow an optimum utilization of the capacity of individual further processing devices, without reducing the production speed on the whole, as well as to provide apparatuses for realizing the aforementioned methods. 
     SUMMARY 
     In an embodiment of the invention, a method for the processing of print products may include conveying individually the print products with a feeding device along a feeding section, transferring individually the print products from the feeding section to a further processing device along a further processing section, and generating control signals from a control unit. The control signals may correspond to further treatment of each individual print product and to the transfer of precisely one print product to the further processing device. 
     In another embodiment of the invention, a method may be provided in which, for each individual print product and/or for each individual operation of transferring precisely one print product to a further processing section, a control signal is generated which determines the further treatment of the print product. 
     In a further embodiment of the invention, a dynamic control or regulation of the further processing of the print products is possible because a control signal is generated for each individual print product and/or for each individual transfer operation, which control signal determines the further processing of the product. By utilizing such dynamic control, there is no fixed division but, rather, a dynamic adaptation of the print product transfer to the production requirements. 
     In another embodiment of the invention, a control signal is generated for each individual print product that is supplied. If a control signal in the form of a release signal is present for the supplied print product, then the respective print products is transferred from a feeding section to a further processing section. On the other hand, if a control signal in the form of a holding signal is present, the respective print product will not be transferred to the further processing section, but is instead transferred from the feeding section to an alternative processing section or to a storage device. 
     For those production operations in which a further processing is possible at higher speeds, meaning a higher number of print products can be processed than can be supplied during each time unit, the release signal is present. A case of this type can occur, for example, if the further processing comprises several further processing steps for which a first processing step is more involved than a following processing step. In that case, all supplied print products are also transferred to the further processing device, even if the capacity of the further processing device is not utilized completely. However, as a result of generating a control signal for each individual transfer operation that involves transferring precisely one print product, a precisely defined feeding of the further processing section with print products is made possible. The further processing section can thus be provided with additional print products, if applicable by using an additional feeding device, so as to achieve a continuous flow of print products along the further processing section and thus an optimum utilization of the capacity of the further processing device. 
     For those production operations where the supplied print products arrive at a higher speed, meaning a higher number of print products supplied during each time unit, than can be handled by the further processing system, the holding signal is present. As a result of the dynamic control of the transfer of the print products from the supplied flow of products (i.e., from the feeding section) to the further processing section, the number of print products removed from the supplied product flow precisely matches the number which can be processed by the further processing device without causing a “print product jam” in front of the further processing device. 
     In another embodiment of the invention, a first control signal determines whether or not the supplied print product in the feeding section that reaches a transfer region is transferred to the further processing section. A second control signal determines when the transfer will take place. In the process, the control signals are usefully generated based on the feeding speed, meaning the number of print products supplied per unit of time, and based on the further processing speed, meaning the number of print products per unit of time which are processed further. 
     Considering the possibility that the supplied flow of print products in the feeding section can have gaps and that unexpected problems can also occur during the further processing, it has proven useful within the framework of embodiments of this invention, so as to ensure an uninterrupted production with optimum production speed, if the print products are transferred from the feeding section to a storage device designed to accommodate a number of print products and from there to the further processing device. It has also proven useful if the control signals are generated based on the number of print products accommodated in the storage device. With this processing variant, the print products removed from the feeding device and/or the feeding section are thus initially supplied to a storage device and are then transferred from the storage device to the further processing section. For example, if the flow of supplied print products in the feeding section contains gaps that can be detected with the aid of a photoelectric cell, the second control signals can be influenced in such a way that no more print products will be transferred from the storage device to the further processing device. In that case, any gaps appearing in the flow of print products for the further processing device can be filled, if applicable, with the aid of an additional feeding device that follows the storage device in downstream direction. If the gaps in the flow of print products are smaller and cannot easily be detected by a photo-electric cell, the removal of print products from the storage device results in a reduction of the filling level for the print products in the storage device. In that case, the further processing speed can be lowered slightly, starting with the desired further processing speed, so that a desired filling level is again achieved for the print products in the storage device. On the whole, by using a storage device and as a result of the dynamic transfer of print products with the aid of control signals for each individual product and/or each individual transfer operation, the actual further processing speed can be allowed to fluctuate around a desired value based on the existing production conditions, respectively the filling level of the storage device. The difference between the actual further processing speed and the desired value for the further processing speed is referred to as a “control offset” in the following. 
     According to another embodiment of the invention, the print products are conveyed along the feeding section while held by a number of grippers, designed to respectively convey a single print product, and are released by the grippers depending on the first control signals. 
     In another embodiment, a further processing of the print products with the aid of an inserter for inserting supplements into finished print products may be provided. For this, the print products may be conveyed along the further processing section inside the pockets of a pocket conveyor which are open at the top, wherein these pockets are supplied with print products in response to the additional or second control signals, if applicable by removing the products from a storage device. The storage device and the transfer device for removing the print products can be embodied as a standard print product feeder. 
     With respect to control technology according to another embodiment of the invention, the print products may be conveyed along the feeding section with the aid of a feeding device such as, for example, a clocked feed conveyor provided with grippers. Precisely one first control signal (e.g., a release signal or a holding signal) may be generated for each conveying cycle during which precisely one print product moves past a removal location along the feeding section. The control can be realized such that for each conveying cycle a clocking rate representing this conveying cycle is compared to a holding rate which is determined based on the feeding speed and the further processing speed. If the clocking rate corresponds to the holding rate, a first control signal in the form of a holding signal may be generated which triggers a holding of a print product in the feeding section. If the clocking rate and the holding rate do not coincide, a first control signal in form of a release signal for releasing a print product may be generated. Following the generating of a holding signal, the holding rate can be increased by a predetermined amount that is usefully determined on the basis of the feeding speed and the further processing speed. Within the meaning of an especially dynamic control, it has proven useful if the clocking rate and the holding rate are reset to 0 once a predetermined limit number is reached, so that a new control regulating cycle can begin. 
     Where the further processing speed is higher than the feeding speed, an optimum use of the capacity of the further processing device may be possible under all operating conditions if additional print products are supplied to the further processing section based on the locations determined by the second control signals and/or based on the times determined for the second control signals. A continuous print product flow may be generated with these additional print products along the further processing section. 
     According to a further embodiment of the invention, an apparatus for processing print products may comprise a feeding device configured to convey the print products individually along a feeding section, a further processing device configured to receive and convey the print products along a further processing section, a transfer device configured to transfer the print products from the feeding device to the further processing device, and a control unit configured to control the transfer of the print products from the feeding device to the further processing device. The control unit may be configured to generate control signals corresponding to further treatment of each individual supplied print product and to the transfer of precisely one print product via the transfer device to the further processing device. 
     In another embodiment of the invention, the transfer device may be provided with a storage device designed to accommodate a number of print products, wherein the print products can be transferred from the storage device to the further processing device. 
     To ensure an optimum output according to another embodiment of the invention, the storage device can comprise a detection device for detecting the number of print products stored therein and for transmitting the respective detection signals to the control unit, wherein the control unit can generate control signals based on the detection signals. The control unit may be designed for adjusting the feeding speed of the feeding device and/or the further processing speed of the further processing device and for generating the control signals based on the feeding speed and/or the further processing speed. An additional feeding device that is also controlled by the control unit can be assigned to the further processing device for supplying additional print products to the further processing section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the invention will be further understood from the following detailed description of an embodiment with reference to the accompanying drawings, in which 
         FIG. 1  depicts a schematic representation of an apparatus according to an embodiment of the invention; and 
         FIG. 2  depicts a flow chart for explaining the method according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The apparatus shown in the embodiment depicted in  FIG. 1  comprises a feeding device such as, for example, a feed conveyor  20  having grippers  22 , a control unit  70 , a further processing device embodied as, for example, an inserter including a pocket conveyor  50 , and an additional feeding device  60  assigned to the pocket conveyor  50 . The print products  10  are gripped along a product fold by the grippers  22  of the feed conveyor  20  and are conveyed while suspended from these grippers  22  in the direction provided by the arrow P, along a feeding section that may also be curved. The feeding speed V 1  can be predetermined, for example by the printing speed of the rotary press. 
     A transfer device  30  comprises a release device  32 , as well as two conveying belts  34  and  36  on which the print products  10  are supplied in the form of an overlapping flow to a storage device  38 . With the aid of the release device  32 , the grippers  22  of the feed conveyor  20  can be opened selectively in response to control signals transmitted via a line  78 , such that the gripped print products  10  are released and deposited on the conveyor belt  34 . In the process, a control signal is generated for each print product  10  that moves past the respective release location  24 , respectively for each gripper  22 , wherein this signal is transmitted from the control unit  70  via a signal line  78  to the release device  32 . The control signal triggers either the release of the print product  10  or the continued holding of the print product  10  by the respective gripper  22 . 
     The released print products  10  are conveyed by the conveying belts  34  and  36 , also called (collectively) an intake conveyor, in the form of an overlapping flow to a storage device  38  from which they can be withdrawn with the aid of a withdrawing device  40  and can be inserted into pockets  52  of the pocket conveyor  50 . In the process, the intake speed V 2  of the intake conveyor  34 ,  36  is controlled via a signal line  80  by the control unit  70 . The control signals which trigger the withdrawal of individual print products  10  from the storage device  38  are transmitted by the control unit  70  via a signal line  82  to the withdrawing device  40 . The pockets  52  of the pocket conveyor  50  which are not supplied by the withdrawing device  40  with print products  10 , e.g. as indicated with the reference  52   a , can be provided with print products  10  by an additional feeding device  60 . The control signals which trigger the withdrawal of individual print products  10  from the additional feeding device  60  are transmitted by the control unit  70  via a signal line  81  to an additional withdrawing device  61 . The number of print products  10  deposited in the storage device  38  is detected with the aid of a detection device  90 , and corresponding detection signals are sent via a signal line  76  to the control unit  70 . A further processing speed V 3  of the pocket conveyor  50  is transmitted via a signal line  74  from the control unit  70  to the pocket conveyor  50 , wherein the further processing speed V 3  corresponds to the desired further processing speed V 4 , modified as necessary by the control offset. 
     On the whole, a control signal can be transmitted to the release device  32  for each individual print product  10  that is supplied by the grippers  22  of the feed conveyor  20  during the operation of the apparatus shown in  FIG. 1 . A withdrawing signal can furthermore be transmitted to the withdrawing device  40  for each individual pocket  52  of the pocket conveyor  50 , so as to ensure an optimum production capacity. During the course of this operation, the processing speed V 3  of the pocket conveyor  50  can be adjusted by the control unit  70  and, following a change in the speed V 3  for the further processing, the conveying speed V 2  of the intake conveyor  34 ,  36  can be changed by adjusting the control signals transmitted to the release device  32  and the control signals transmitted to the withdrawing device  40 . Any gaps in the flow of the supplied print products  10  can be compensated for by withdrawing previously deposited print products  10  from the storage device  38 . If problems occur during the further processing in the pocket conveyor  50 , released print products  10  can be stored temporarily in the storage device  38 . In order to compensate for these fluctuations in the production, the control signals transmitted via the signal lines  78  and  82  to the release device  32  and/or the withdrawing device  40  can be generated based on the number of print products  10  deposited in the storage device  38  and detected by the detection device  90 . For compensating possible production fluctuations, the further processing speed V 3  of the pocket conveyor  50  can be allowed to fluctuate by a control offset around a desired further processing speed V 4 . The desired further processing speed V 4  can be adjusted with the aid of an adjustment device that is assigned to the control unit  70  and is not shown in  FIG. 1 . For the embodiment of the invention shown in  FIG. 1 , the desired further processing speed V 4  of the pocket conveyor  50  was increased. This is obvious from the increasingly wider gaps between the print products  10  transported further by the grippers of the feed conveyor  20  for the operating mode shown in  FIG. 1 , starting from the left picture edge toward the right picture edge, wherein more print products  10  were transferred from the feed conveyor  20  to the pocket conveyor  50 . 
     The mode of operation for the apparatuses according to the invention and/or the realizing of the methods according to the invention are explained in the following with the aid of an example: 
     For this example, the feeding speed of the feed conveyor  20  is preset to 60,000 copies per hour by the production unit for the printing press while the speed for the further processing device (e.g., including pocket conveyor  50 ) amounts to 40,000 copies per hour. Thus, only 66.6% of the supplied print products  10  can be processed further. It means that each third print product  10  that is supplied must move past the transfer region while suspended from a gripper  22  of the feed conveyor  20  and/or that the flow of supplied print products  10  must correspondingly be divided during a split step, wherein a split rate amounts to 66.6%. In general, the split rate (S) can be expressed as follows: 
                   S   =     100   ·         V   4       V   1       ⁢           [   %   ]               (   1   )               
and wherein the split step can be expressed as follows:
 
     
       
         
           
             
               
                 
                   
                     100 
                     
                       ( 
                       
                         100 
                         - 
                         S 
                       
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                   ⁢ 
                   
                       
                   
                   [ 
                   
                     number 
                     ⁢ 
                     
                         
                     
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                     of 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     cycles 
                   
                   ] 
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
     
     It is assumed in this case that a clocked feed conveyor  20  is used for which a single print product  10  moves past the release/transfer location  24  during each conveying cycle. If the desired processing speed V 4  of the further processing device (e.g., pocket conveyor  50 ) is higher than the feeding speed V 1  of the feed conveyor  20 , a corresponding withdrawing rate (A) and withdrawing step are computed for the withdrawing device  40 : 
     
       
         
           
             
               
                 
                   A 
                   = 
                   
                     100 
                     · 
                     
                       
                         
                           V 
                           1 
                         
                         
                           V 
                           4 
                         
                       
                       ⁢ 
                       
                           
                       
                       [ 
                       % 
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                   ( 
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                     and 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     the 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     withdrawing 
                     ⁢ 
                     
                         
                     
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                     step 
                   
                   = 
                   
                     
                       100 
                       
                         ( 
                         
                           100 
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                         ) 
                       
                     
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       number 
                       ⁢ 
                       
                           
                       
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                   ( 
                   4 
                   ) 
                 
               
             
           
         
       
     
     The following cases can thus occur:
     1. V 1 &gt;V 4 . In that case, the flow of supplied print products  10  must be divided. Only enough print products  10  to equal the number that will be processed further are removed from the flow of supplied print products  10  (i.e., from the feed conveyor  20 ). In principle, products are always removed and a holding signal is generated for the release device  32  once a split step is reached.   2. V 1 =V 4 . In that case, the flow of supplied print products  10  in the feed conveyor  20  does not have to be divided because all print products  10  are transferred from the grippers  22  of the feed conveyor  20  to the intake conveyor  34 ,  36  and all print products  10  are transferred with the aid of the withdrawing device  40  to the pocket conveyor  50 .   3. V 1 &lt;V 4 . In that case, the supplied print products  10  in feed conveyor  20  are distributed to the pockets  52  of the pocket conveyor  50 , wherein all supplied print products  10  are processed further while distributed to the pockets  52 . This is achieved through a corresponding triggering of the withdrawing unit  40  once a withdrawing step is reached.   

     An embodiment of a method according to the invention is explained in the following with the aid of the flow chart shown in  FIG. 2 . 
     According to an embodiment of the method shown in  FIG. 2 , a check is made in step S 1  to determine whether a print product  10  has reached a release location  24  of the feed conveyor  20 . If a print product  10  reaches the release location  24 , a clocking rate (NbrClocks) is incremented (step S 2 ). A check is made at the same time to determine whether the clocking rate for the embodiment explained with the aid of  FIG. 1  has reached the preset limit value of, for example, 100. If the value of 100 is exceeded, the clocking rate is reset to 0 (step S 4 ). If the clocking rate of 100 has not yet been exceeded, the clocking rate is compared in step S 5  to a holding rate UINT (nextSplitStep+0.5). If the clocking rate does not correspond to the holding rate, a release signal (acceptCopy:=1) is generated in step S 7  for the respective print product  10  and is transmitted to the release device  32 , so that the respective print product  10  is deposited on the intake conveyor  34 ,  36  and is supplied to the pocket conveyor  50  for the further processing. However, if is it determined during step S 5  that the clocking rate corresponds to the holding rate, a check is made during step S 8  to determine whether the holding rate is unequal to 100 and, if it is determined that this rate is in fact unequal to 100, then a holding signal (acceptCopy:=0) is generated and is transmitted to the release device  32 , so that the corresponding print product  10  is conveyed further along the feeding section while suspended from the gripper of the feed conveyor  20 . The holding rate is simultaneously increased by a split step during the step S 6 , wherein this split step is computed as explained in the above. 
     For the case where the further processing speed is higher than the feeding speed, the print products are divided and distributed accordingly to the individual pockets  52  of the pocket conveyor  50 . 
     The invention is not restricted to the embodiment explained with the aid of  FIG. 1 . Differently designed feeding devices can also be used for feeding the print products  10 . In the same way, the further processing of the print products  10  can also take place in differently designed further processing devices or machines. In addition, the intake conveyor  34 ,  36  can take the form of a single conveyor belt and, if applicable, the storage device  38  can be omitted. One skilled in the art can furthermore deduce other changes to be made based on the embodiment of the invention that is explained with the aid of  FIG. 1 . 
     It will be understood that the above description of the embodiments of the invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.