Abstract:
A system comprises alternative processing sections for use in the further processing of products. A separator, at which a transport section is divided into several alternative transport sections for the further processing of products in processing stages, is provided. A sensor, that detects the phasing of the products, is located upstream of the separator. A request from the sensor acts on a drive which actuates the separator through a control device. A further sensor, which detects the product phasing, is located on each of the at least two transport sections. This further sensor is connected to a drive for the processing stage served by respective ones of the separate transport sections. The drive of each such processing stage is controlled independently of the drive for the respective transport section by a suitable control unit which takes into consideration the detected product phasing for the associated transport section.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This patent application is the U.S. National Phase, under 35 USC 371, of PCT/EP2005/051458, filed Mar. 31, 2005; published as WO 2005/095245 A1 on Oct. 13, 2005, and claiming priority to DE 10 2004 015 963.7, filed Apr. 1, 2004, the disclosures of which are specifically incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention is directed to a system, which is provided with alternative processing sections for use in the further processing of products, and with a longitudinal folding apparatus, as well as to a method for the synchronous operation of a folding apparatus. A shunt is used to divide a product path into a plurality of alternative product paths. An upstream product sensor detects a product phase relationship and controls the shunt.  
       BACKGROUND OF THE INVENTION  
       [0003]     In folding apparatuses, useable, in particular, for products of a rotary printing press, product sections or products are further processed in several successive and partially alternatively selectable processing stages. The alternative assignment of each of the product sections or products to one or another of several processing stages takes place by the use of a product shunt. In generally conventional folding apparatuses, the product shunt, as well as the tools or apparatus of the subsequent processing stages, are typically driven via gears from a main drive mechanism of the folding apparatus or its transport devices and are synchronized with them. However, if the product sections or products, prior to their entry into the shunt and/or prior to their entry in the downstream located processing stage, are not always exactly oriented, damage to the products can occur. This may result in a reduction in quality of the resultant product and may even result in the stoppage of the installation, either in the course of the passage of the product sections through the shunt, or during subsequent further processing of the product sections.  
         [0004]     A product shunt of a folding apparatus, with two downstream located longitudinal folding apparatuses, is disclosed in DE 198 02 995 C2. A sensor, for use in detecting the phase relation of the product, is located upstream of the product shunt. Another sensor is located downstream of each of the two succeeding longitudinal folding apparatuses and is usable for detecting jams in these apparatuses. The three sensors, another sensor, which is usable for detecting the number of revolutions of the main drive mechanism, as well as a switching device for setting a production type, are all connected with a regulating arrangement for controlling the product shunt. The regulating arrangement acts on a step motor which is connected with the shaft of the product shunt.  
         [0005]     A longitudinal folding apparatus is known from DE 40 20 937 C2. A folding blade can be moved toward and away from the folding apparatus by the use of a cam disk.  
         [0006]     DE 199 43 165 A1 discloses a folding blade of a longitudinal folding apparatus. The folding blade can be moved into and out of the folding apparatus by the use of coils which generate electromagnetic force.  
         [0007]     Longitudinal folding apparatuses are generally known and are employed in the printing industry, primarily in the finishing of printed products. The printed products are pushed into the folding gap by the folding blade and are longitudinally folded in it. The entry direction of the printed products into the longitudinal folding apparatus extends transversely with respect to their subsequent movement through the folding gap. It is therefore necessary to slow the printed products down, prior to their passage through the folding gap. Braking brushes, which gradually slow down the incoming printed products by friction, as well as stationary buffers, against which the printed products bump, and which printed products are abruptly braked by this, are known for this purpose in generally known longitudinal folding apparatuses. To avoid damage to the printed products at the buffers, it is necessary to reduce the speed to a low value. However, this value may in no case be zero. If the speed becomes zero, the printed products do not reach the buffer, and a jam occurs. The extent of the slow-down, by the use of the brushes, is determined by the friction that they exert on the printed products, and ultimately by the position of the latter. If it is intended to fold printed products of varied thickness, while the position of the brushes remains the same, the friction, which is exerted by the brushes, greatly increases with the thickness of the products. A thick product may possibly get stuck between the brushes and thus will not reach the buffer, while a thin product will bump against the buffer with such great speed that it becomes damaged in the process. Therefore, the position of the brushes must be matched to the thickness of the printed products.  
         [0008]     The friction between printed products and brushes is also a function of the surface condition of the printed products. Products made of smooth paper can bump against the buffer too rapidly, while products made of rough paper, even though being of the same thickness and the same weight as the smooth paper products, possibly do not reach the buffer.  
         [0009]     A further problem arises from the fact that the amount of kinetic energy of the printed products, which is dissipated at the brushes, is a result of the product of brush friction and the length of the braking path. The kinetic energy dissipation is independent of the entry speed of the printed products into the brushes. Changes of this entry speed, regardless of whether these changes are intentional or unintentional, therefore have a very strong effect on the bumping speed of the printed products on the buffer.  
         [0010]     For all practical purposes, it is necessary to adjust the position of the brushes for each printing job in order to assure the correct functioning of the longitudinal folding apparatus. Based on the multitude of influencing parameters which are involved, the adjustment of the brush position can often only take place empirically, which trial and error adjustment results in a large outlay of time and costs.  
         [0011]     A further basic problem, which occurs in connection with high entry speeds of the printed products, even when they are braked to such an extent that damage, because of bumping against the buffer, does not occur, results from the fact that the printed products change their position and orientation in the course of the braking process. In many cases, following its braking, a printed product assumes a twisted position in the longitudinal folding apparatus, in which twisted position, the front edge of the printed product no longer extends perpendicular to the folding gap. The printed product is therefore not folded, in the desired way, in the center in the course of subsequent folding, during which subsequent folding the printed product is pushed, in its twisted position, into the folding gap by the folding blade, and now has an oblique fold.  
         [0012]     Premature folding can also occur if printed products are delayed in their entry the longitudinal folding apparatus. This is true particularly if driving of the folding blade, which is the tool of the processing change is provided by a main drive mechanism.  
         [0013]     EP 1 211 212 A2 shows a folding blade control device of a longitudinal folding apparatus with a sensor arranged upstream of the longitudinal folding apparatus. A control of a folding blade triggering time is determined as a function of the speed of the transported product sections, as determined by the sensor.  
         [0014]     DE 198 28 625 A1 relates to a transverse folding device for the transverse folding of sheets. It includes a folding blade that is inclined in the transport direction, as well as an automatic control for the position or the correct separation of the sheets. The device is capable of transversely folding sheets of paper once or several times.  
       SUMMARY OF THE INVENTION  
       [0015]     The object of the present invention is directed to increasing the product quality and the operational dependability in a system with alternative processing sections which are usable for the further processing of products, and in a longitudinal folding apparatus. The object of the present invention is also directed to the provision of an appropriate method for the synchronous operation of a folding apparatus.  
         [0016]     In accordance with the present invention, this object is attained by the provision of a system, with alternative processing tracks for use in the further processing of products in a longitudinal folding apparatus. A former and a transverse folding apparatus are arranged upstream of the longitudinal folding apparatus. A shunt is located where a product conveying path splits into a plurality of alternate transport tracks. A sensor detects the product phase relation upstream of the shunt. A signal from the sensor acts on a shunt drive via a control device. A further sensor is arranged on each of the transport tracks.  
         [0017]     The advantages which can be obtained by the present invention consist, in particular, in that, on the one hand, the product quality, and, on the other hand, the operational dependability, or the availability of the folding apparatus, are considerably increased. This is advantageously accomplished by the optical detection of the position of the products, which are situated upstream of the two longitudinal folding apparatuses, and by the synchronization of the folding blade, which is driven mechanically independently from the conveying system and/or a movable buffer and/or an optical detection of the position of the products upstream of the shunt.  
         [0018]     By the provision of the optical detection of the phase relation of the products, directly prior to longitudinal folding, it is possible to ideally synchronize the time of folding and to correct it, if required. The quality of the product is further improved if, in addition, movable buffers are also synchronized by the use of the optical detection. Such synchronization reduces the product bumping and assures an exact product alignment.  
         [0019]     In an advantageous embodiment of the present invention, a gentle braking of the products, such as, for example, printed products, is achieved at the longitudinal folding apparatus by the use of the movable buffer. The kinetic energy, with which the products bump against the moving buffer, is reduced in comparison with the kinetic energy which is released in case of the products bumping against a stationary buffer. If a difference between an entry speed of the products, and a speed of the moving buffer is selected to be sufficiently low, it is even possible to completely prevent the above-described unintentional effects that are caused as a result of released kinetic energy. It is possible, in this case, to also absorb very high entry speeds of the products, by the use of the movable buffer. The products can accordingly be gently braked. A braking effect, which is independent of the mass, the thickness and the surface condition of the incoming products, can be achieved by the use of the movable buffer. It is thus possible to process different products without it being required to first adapt the longitudinal folding apparatus to each one of them.  
         [0020]     In a particularly preferred embodiment of the present invention, the longitudinal folding apparatus contains a control unit which controls a reduction of the speed of the buffer on the braking path. A definite braking of the incoming products is possible, by the use of the control unit. The incoming products come to a buffer, at a predetermined defined position, and, in the process, are optimally aligned for the subsequent folding process. Alternatively, the incoming products can bump against a second, stationary buffer, which determines the desired position of the products for the subsequent folding process, at a reduced speed, at which reduced speed, no damage of the products because of their bumping is to be expected.  
         [0021]     If the control unit has an input for a signal which input is, in particular, representative of the entry speed of the products, it is possible to comfortably match the speed of the buffer with changing entry speeds of the products by the use of the control unit.  
         [0022]     A sensor, for use in detecting incoming products, is advantageously placed upstream of the braking path and is coupled to the control unit. The control unit can thereby synchronize the movement of the movable buffer in such a way that, at the entry to the braking path, a detected incoming product meets the buffer, which buffer moves at approximately the entry speed. The speed of the buffer, at the entry to the braking path, can be less than the incoming product entry speed as long as the difference between the two speeds is not so great so that damage to the product appears likely. The buffer speed can also be slightly greater than the product speed. In this case, contact between the two will then occur at a later location on the braking path, at which the speed of the buffer has then become slower than the speed of the product.  
         [0023]     Preferably, the buffer is configured as a revolving cam, whose direction of movement crosses a braking path of the product, at least on one path section. With the aid of a revolving cam which is arranged on a rotatable body, such as, for example, a disk, a roller or an eccentric device, the buffer can be conveyed in continuous movement, without a reversal of the driving direction, from one end of the braking path, where it is moving out of contact with the product, back to its start, where it is coming into contact with the product, in order to catch the next arriving product there. In this case, the rotatable body can be provided as a module which can be retrofitted to the longitudinal folding apparatus and which is located above a folding table having the folding gap. Alternatively, the rotatable body with the cam may be arranged underneath the folding table as a module which is fixedly integrated into the longitudinal folding apparatus. In a preferred embodiment of the present invention, the body consists of several disks, which are arranged axially next to each other, and each of which has at least one cam on its circumference.  
         [0024]     In a variation of the present invention, the cam can be arranged on a circulating endless belt. This endless belt has a section which extends parallel with the braking path.  
         [0025]     Preferably at least one rotatable body, having a cam or an endless belt, is arranged on both sides of the folding gap, each of which rotatable body supports synchronously movable buffers. Two rotatable bodies, or two endless belts, per side of the folding gap are preferred. In this way, a correct alignment of the braked product is assured. Additionally, unintended twisting of the product, in relation to the folding gap, is made more difficult.  
         [0026]     At least one motor for driving the rotatable bodies, or the endless belts, can be provided on both sides of the folding gap. This motor can be a highly dynamic servo motor or can be an electric motor. However, an embodiment of the present invention is also possible wherein a single motor drives the rotatable bodies or endless belts on both sides of the folding gap by the use of a continuous shaft.  
         [0027]     A speed of the buffer, at the entry to the braking path, of at least 90% of the entry speed of the product is preferred. In that case, a sufficiently small difference exists between the speed of the buffer and the entry speed, so that only little kinetic energy is released when the products bump against the buffer.  
         [0028]     It can be advantageous, in accordance with the present invention, to also provide braking brushes, besides the movable buffer, in the longitudinal folding apparatus. The inclusion of these braking brushes insures that braking of the products can be further gentled. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows.  
         [0030]     Shown are in:  
         [0031]      FIG. 1 , a schematic side elevation view of a longitudinal folding apparatus in accordance with the present invention, in  
         [0032]      FIG. 2 , a top plan view of the longitudinal folding apparatus of  FIG. 1 , in  
         [0033]      FIG. 3   a ) to  FIG. 3   d ), a sequential process of braking a printed product, in  
         [0034]      FIG. 4 , a speed/time diagram for a printed product in a first mode of operation of the longitudinal folding apparatus in accordance with the present invention, in  
         [0035]      FIG. 5 , a speed/time diagram for a printed product in a second mode of operation of the longitudinal folding apparatus of the present invention, in  
         [0036]      FIG. 6 , a side elevation view of a further longitudinal folding apparatus in accordance with the present invention, in  
         [0037]      FIG. 7 , a top plan view of the longitudinal folding apparatus of  FIG. 6 , in  
         [0038]      FIG. 8 , a perspective representation of a braking device with a movable buffer in accordance with the present invention, in  
         [0039]      FIG. 9 , a perspective representation of a braking device with a folding table and frame, and in  
         [0040]      FIG. 10 , a schematic representation of a system with alternating processing sections for the further processing of products in accordance with the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]     A processing stage  01 , which is configured as a longitudinal folding apparatus  01 , is represented in  FIGS. 1 and 2 , in a side elevation view in  FIG. 1 , and in a top plan view in  FIG. 2 . The longitudinal folding apparatus  01  consists of a folding table  04 , in which an elongated folding gap  06  is provided, as seen in  FIG. 2 . A pair of folding rollers  07  have been placed against each other. Only one of the rollers  07  is visible in  FIG. 1 , while the other is hidden. This pair of folding rollers  07  are arranged underneath the folding table  04  at the level of a folding gap  06  in such a way that they form a folding roller gap which is oriented parallel with the folding table gap  06  and which is located directly underneath it. Pivotable folding levers  21  are provided on the folding table  04 . These folding levers  21  hold a folding blade  03  above the folding gap  06 , which folding blade  03  is also oriented parallel to the folding gap  06 . In the course of a pivot movement of the folding levers  21 , the folding blade  03  can enter into the folding gap  06 . An elongated buffer  08  is arranged in an end area of the folding gap  06  and is oriented transversely, in respect to the folding gap  06 , on the folding table  04 . Braking brushes  09 , which are facing the top of the folding table  04 , are fastened on the buffer  08 . The folding blade  03  is preferably embodied in the manner of a blade  04 , which is pivotable with respect to the folding table  04 , in contrast to a rotating cutter. The folding blade  03  can be moved up and down relative to the folding table  04 . For example, the folding blade  03  may be seated in levers  43 , which are in turn, pivotably seated around a shaft  44 , as is shown in  FIG. 9  in respect to the folding table  04 . However, in another embodiment, the blade  03  can also be arranged eccentrically on a continuously turning rotatory body. Folding blade  03  can also be eccentrically arranged on a turning planetary wheel. In an advantageous embodiment of the invention, a mechanically independent drive mechanism, as will be described below has been provided.  
         [0042]     In a preferred embodiment of the present invention, which is indicated only by dashed lines in  FIG. 1 , a folding blade drive mechanism  05 , which is independent of the conveying or production devices, is assigned to the folding blade  03 . This folding blade drive mechanism  05  can be configured as a motor  05 , for example, which motor  05  lowers or raises the folding blade  03  in a clocked, or timed manner in respect to the position of a product  02  on the folding table  04  via a gear mechanism, such as, for example, an eccentric device or a crank drive. For example, the control of the drive mechanism  05  can take place by the use of a control device  10 , which is represented in dashed lines. Control device  10  synchronizes the movement of the folding blade  03  with the product flow, either by the use of information regarding the speed of a transport system conveying the product  02 , or by the use of a signal from a sensor, such as, for example, a sensor  18  which will be discussed below, and, which sensor  18  is arranged upstream of the folding gap  06  and detects the product  02 .  
         [0043]     A rotatable body  15  in the form of, for example, disks  15 , is respectively arranged on each of the sides of the folding gap  06 . An axis of rotation of the rotatable body  15  extends perpendicular, with respect to the folding gap  06 . Two buffers  13 ,  14 , such as, for example, cams  13 ,  14 , are arranged, such as, for example, by being welded to the circumference of the disks  15 . Starting from any one of the cams or buffers  13 ,  14 , a respective distance between the successive cams  13 ,  14 , along the length of the disk  15  preferably is of the same length. Each of the two disks  15 , which are located on opposite sides of the folding gap  06 , is connected with a motor  16 , such as, for example, with an orientation-regulated electric motor  16 , and is preferably synchronously driven by its respective motor  16 . In a variation of the preferred embodiment, which is not specifically represented, the two disks  15  can be connected with each other by a continuous shaft and can be driven by a common motor  16 . A first side of a braking path  24  for printed products  02  is delimited by the upper surface of the folding table  04 , and is delimited on a second side by a shell face of the two disks  15  facing this folding table upper surface. A distance between the upper surface of the folding table  04  and the shell faces of the disks  15  is greater than the height of the cams  13 ,  14 . The motors  16  are controlled by a control unit  19 , or a control device  19 , which is furthermore connected to the sensor  18 . For the detection of products  02 , such as, for example, printed products  02 , which are entering the brake path  24  delimited by the toothed disks  15  and the folding table  04  at an entry speed v 0 , as seen in  FIGS. 5 and 6 , the sensor  18  has been placed upstream of the braking path  24  on the inlet side. The control unit  19  furthermore has an input for receiving a signal specifying the speed “v” with which the printed products  02  enter the braking path  24 . For example, this signal can be derived from a web speed signal of a web-fed printing press producing the printed products  02 , or can be made available from the control console of such a press. However, it is also possible to detect the speed “v” of each individual arriving printed product  02 , for example with the aid of two sensors  18  which are successively being passed by the printed products  02 , and to provide this speed “v” it to the input of the control unit  19 .  
         [0044]     In a variation of the first preferred embodiment, as seen in  FIGS. 6, 7 , instead of the disk  15  supporting the cams  13 ,  14 , a toothed belt  12 , in the form of an endless belt  12 , which belt  12  extends parallel with the folding gap  06 , runs on both sides of the folding gap  06  and over two rotatably supported, and spaced, gear wheels  11 , such as, for example, pulleys  11 . Two buffers  13 ,  14 , such as, for example, cams  13 ,  14 , have been respectively welded, or otherwise secured to the toothed belt  12 . Again starting from any one of the cams  13 ,  14 , or buffers  13 ,  14  a distance between subsequent or sequential ones of the cams  13 ,  14 , along the length of the toothed belt  12 , is of the same length. Two of the gear wheels  11 , which are located on different, opposite sides of the folding gap  06 , are connected with each other by the continuous shaft  17 , as seen in  FIG. 7 , and are connected with the common motor  16  by shaft  17 , which motor  16  may be, for example an orientation-regulated electric motor  16 . Gear wheels  11  are synchronously driven by the motor  16 . The braking path  24  for the printed products is delimited, on the one side, by the top of the folding table  04 , and on the other side by a strand of each of the two toothed belts  12  facing this top surface of the folding table  04 . The distance between the surface of the folding table  04  and the strands of the two toothed belts  12  is slightly greater than the height of the cams  13 ,  14 . The motor  16  is controlled by the control unit  19  which, as mentioned in connection with  FIG. 1 , is connected to the sensor  18 .  
         [0045]     In an embodiment of the present invention, which is not specifically represented, the disks  15 , or the endless belts  12  and gear wheels  11 , can be arranged on a side of the folding table  04  that is facing away from the printed product  02 . The cams  13 ,  14  must then extend up through the folding table  04  in such a way that they project out of the surface of table  04  which is facing the printed product  02  to thereby function in the manner of a movable buffer for the printed product  02 , at least over a portion of the path of travel of the printed product  02 .  
         [0046]     The process of braking of the incoming printed product  02  is represented in  FIGS. 3   a ) to  3   d ), using the embodiment of the rotatable body  15 . A representation of the folding blade  03  and of the folding rollers  07  has been omitted for the sake of clarity. Wherever possible, the embodiment with an endless belt  12  is shown in parentheses.  
         [0047]     The printed product  02  entering the longitudinal folding apparatus  01  at an entry speed v 0  is detected by the sensor  18 , as shown in  FIG. 3   a ). By use of the signal which is present at the input of the control unit  19 , which signal is either time of the detection of the product signal and/or a speed signal, the control unit  19  synchronizes the movement of the disks  15  (toothed belt  12 ) with that of the printed product  02  in such a way that, at the entry to the braking path  24 , the printed product  02  meets a cam  13  or  14 , in  FIG. 3   b ). The cam  13 , which, at this time, moves slower than the printed product  02  thus brakes the printed product  02  without damaging it. In the course of the passage of the cam  13  through the braking path  24 , as shown in  FIG. 3   b ), the control unit  19  continuously slows the rotating movement of the disks  15  (the movement of the toothed belts  12 ) until the printed product  02  has, for example, reached the braking brushes  09  and is slowed further by them. The printed product  02  finally encounters the buffer  08  at a speed “v”, at which it is not damaged by bumping into the buffer  08 . However, in the case where the braking brushes  09  are only arranged downstream of the location at which the printed product  02  comes out of engagement with the cam  13 , the printed product  02  initially moves evenly at a reduced speed.  FIG. 3   c ) shows the situation shortly before the encounter of the printed product  02  with the buffer  08 , and  FIG. 3   d ) the situation shortly after the encounter of the printed product  02  with the buffer  08 . As soon as the cam  13  and the printed product  02  come out of engagement with each other, the disk  15  (the toothed belt  12 ) can be accelerated again. Now, the second cams  14  are located at the entry to the braking path  24 , in time with the arrival of a subsequent printed product  02 , and have a speed “v” which is suitable for braking this subsequent printed product  02 .  
         [0048]     In a simplified embodiment of the longitudinal folding apparatus  01 , the braking brushes  09  can be omitted. However, in this simplified embodiment, it is necessary to brake the cams  13 ,  14  to a lower speed “v”, as these cams  13 ,  14  are passing the buffer  08 , than would be needed if there were braking brushes  09 . This is necessary in order to prevent damage to the printed products  02  at the buffer  08  and the rebounding of the printed product off the buffer  08 . Therefore, a larger capacity motor  16  is required in this simplified embodiment.  
         [0049]     In a subsequent folding step, the printed product  02  is pushed, by the vertically reciprocable folding blade  03 , through the folding gap  06  and into the gap which is defined between the two folding rollers  07 , in a generally known manner, and is longitudinally folded in this way. This folding strip is a generally known process, so that it will not be addressed in greater detail at this point.  
         [0050]     By way of example,  FIG. 4  shows the chronological development, over time (t), of the speed “v” of a printed product  02  during its passage through the braking path  24 .  
         [0051]     The printed product  02  enters the longitudinal folding apparatus  01  at an entry speed v 0 . The cams  14  or  13  initially precede the printed product  02  at a speed v 1 , which speed v 2  is 90% of the entry speed v 0 . At the time of an initial engagement of the printed product  02  against the cams  14  or  13 , at the time t 0 , the relative speed between the printed product  02  and the cams  14  or  13  is therefore one tenth of the printed product entry speed v 0 . Because the relative speed enters the kinetic energy quadratically, this means that, in the course of the initial engagement or bumping of the printed product  02  against the cams  14  or  13 , at the time t 0 , only one hundredth of the kinetic energy is released as would be released in a case of the bumping or contact of the printed product  02  against the stationary buffer  08 , at an unbraked entry speed v 0 .  
         [0052]     The speed of the cams  13 ,  14  is continuously reduced by the control unit  19  between the time t 0  and the time t 1 , at which time t 1 , the printed product  02  passes into the effective range of the braking brushes  09 . A descending straight line for the speed v 1  results between these times t 0  and t 1 , in the speed/time diagram, as shown in  FIG. 4 . Braking of the printed products  02 , by the control unit  19 , can also take place in a differently shaped curve. Starting at the time t 1 , the printed product  02  is now additionally braked by the braking brushes  09 , so that the straight line between the times t 1  and t 2  now shows a curvature, again as shown in  FIG. 4 . When the printed product  02  now finally bumps against the stationary buffer  08 , at the time t 2 , where it is completely braked, it shows a very slow speed v 2  in comparison to the entry speed v 0 . Therefore, bumping of the very slowly moving printed product  02 , against the buffer  09 , is very gentle and very little kinetic energy is released. Starting at the time t 1 , at which the contact between the printed product  02  and the cams  14  is discontinued, the control unit  19  can now accelerate the toothed belt  12  back up to the speed v 1  in order to synchronize the cams  13  or  14  with the speed of the incoming, following printed product  02 .  
         [0053]      FIG. 5  shows the development of the speed “v” of a printed product  02 , in the course of passing through the braking path  24 , in connection with a further simplified embodiment of the longitudinal folding apparatus  01  in accordance with the present invention. The disk  15 , which is supporting the cams  13 ,  14  (or by the endless belts  12 ), is driven at a constant speed. Here, too, the printed product  02  enters the longitudinal folding apparatus  01  at the entry speed v 0 . This time, the cams  14  or  13  precede the printed product  02  at a speed v 3 , which is reduced, in comparison with the speed v 1  that was used in connection with  FIG. 4 . At the time t 0 , the printed product  02  has caught up with the more slowly cams  14  or  13  and bumps against them. The speed “v” of the printed product  02  is reduced from v 0  to v 3 , which is the speed of the cams  14  or  13 . Between the time t 0  and the time t 1 , at which the printed product  02  reaches the effective range of the braking brushes  09 , the speed v 3  of the cams  14  or  13 , and therefore the speed “v” of the printed product  02 , remains approximately constant. However, for the disk  15  this speed relationship only applies approximately to a contact range within a narrow angle of rotation, such as, for example, less than 20°. Following the vertex point of the cam  13 , which is the point of the shortest spacing distance of the tip of the cam  13  from the folding table  04 , which vertex point is distinguished in that the line which connects the center of the disk  15  with the front edge of the cam  13  extends perpendicularly with respect to the plane of the folding table  04 , at a constant rotary speed, the cam  13  now runs away, or separates itself from the braked printed product  02  in the plane of the folding table  04  at a slightly faster speed. This increased separation speed is not specifically represented in  FIG. 5 .  
         [0054]     The printed product  02  is now further braked by the braking brushes  09 , which further speed reduction becomes noticeable by a curvature of the graph which had been straight up to that time, while the cams  14  or  13  continue to run, so that they become again separated from the printed product  02 . Finally, at the time t 2  the printed product  02  bumps against, or engages the stationary buffer  08  at the speed v 4  and is thereby completely braked.  
         [0055]     If, for a simpler estimation, the effect of the braking brushes  09  on the speed “v” is not considered, by assuming that no braking brushes  09  were provided, and if it is further assumed that the speed v 3  of the cams is half the magnitude of the entry speed v 0  of the printed product  02 , the same amount of kinetic energy is released during the bumping of the printed products  02  against the cams  14  or  13  as is released in the course of the bumping of the printed product  02  against the buffer  08 . This is because, during both bumping processes, the same amount of relative speed between the printed product  02  and the cams  14 ,  13 , or at the buffer  08 , prevails. This means that during both bumping processes just one fourth of the amount of kinetic energy is set free as would be released if the printed product  02  were to bump against, or impact, the stationary bumper  08  at the unbraked entry speed v 0 . If the braking brushes  09  are provided, it is possible to select v 3 &gt;v 0 /2, and v 4 &gt;v 0 /2, so that both of bumping or impact processes are softened.  
         [0056]     In an advantageous embodiment of the present invention, and with the disk  15 , the bumping point or impact point of the product  02  with the cam  13  is located ahead of the vertex of the cam  13 , or, in other words, is located ahead of the point of the shortest distance of the free end or tip of the cam  13  from the folding table  04 , which shortest distance is distinguished by the line which connects the center of the disk  15  with the front edge of the cam  13 , and which line is extending perpendicularly with respect to the plane of the folding table  04 .  
         [0057]     The longitudinal folding apparatus  01 , with the disks  15 , or with the endless belts  12 , arranged underneath the folding table  04 , is preferred, particularly in the situation in which the disks  15 , or the endless belts  12 , together with the gear wheels  11 , as well as the motor  16  or the motors  16 , have been fixedly installed in the table. The longitudinal folding apparatus  01 , with the disks  15 , or the endless belts  12 , arranged above the folding table  04  is preferred in the case where the toothed belts  12 , with the gear wheels  11 , and with the motor  16 , are intended to be configured as a removable module.  
         [0058]      FIG. 8  shows, in a perspective view, an advantageous embodiment of a braking arrangement  26 , in accordance with the present invention, and having a movable buffer  13 ,  14 . Braking arrangement  26  has a group of several, and here has four, disks  15  on each of the two sides of the folding gap  06 . Each disk  15  supports one cam  13  on its circumference, and each group of disks  15  is driven by a motor  16 . In principle, this arrangement could be either releasably or non-releasably connected with a frame  27  or support  27 , or with the folding table  04 , as is depicted in  FIG. 9 . However, in an advantageous arrangement of the present invention, the braking device  26  is configured as a module  26  which is arranged to be movable with respect to the frame  27  in such a way that the space directly above the folding table  04  can be kept clear. To accomplish this end, the braking device  26  is seated so that it is pivotable with respect to the frame  27 . The braking device  26  has groups of supports  29  for receiving the disks  15 , which supports  29  are either pivotable around a shaft  28  that is fixed in place on the frame, or are pivotable around a shaft  28  which is rotatably seated on the frame  27 . Pivoting of the supports  29  can take place either manually or, as represented, by drive assemblies  31 , such as, for example, by one or by several cylinders, which cylinders can be charged with a pressure medium. To this end, the cylinder is intended to be fixed on the frame, for example, and the piston end is hinged to the supports  29 , or vice versa. Fixed on the frame is understood here to include that the seating of the shaft  28 , or of the cylinder, can be connected with further components, which further components are arranged in a fixed orientation with respect to the frame  27  or to the folding table  04 . If now the folding table  04 , or the folding blade  03  is to be made accessible, the braking device is pivoted away by actuating the drive means  31 . Alternatively this pivotal movement can be accomplished manually. The braking module  26 , whether it is arranged movably or fixed on the frame, is suitable, in a particularly simple manner, for use in retrofitting conventional longitudinal folding apparatuses  01 .  
         [0059]     The principle of operation and utilization of the movable buffers  13 ,  14 , as well as the particular embodiments of the arrangement, in accordance with the present invention can be advantageously used, considered by themselves, but can also be used, as a whole, within a system  32  with alternative processing sections.  
         [0060]      FIG. 10  schematically shows such a system  32 , with alternative processing sections, for use in further processing products  02 , such as, for example, intermediate products  02 , and in particular for use in the further processing of printed products  02  in a folding apparatus.  
         [0061]     Intermediate products  02 , such as, for example, products  02  which are already transversely cut and/or which are transversely folded sections of printed products, are conveyed along a track  33 , such as, for example, a conveying track  33 , toward a shunt  34 , such as, for example, a splitting device  34 . At the shunt  34 , the transport track  33  is split into several, and here as specifically illustrated as two alternative tracks  36 ,  37 , such as, for example, two transport tracks  36 ,  37 , and in particular, into two processing tracks  36 ,  37 , for use in accomplishing the further processing of the intermediate products  02 . The splitting device or shunt  34  has, for example, tongues  38 , such as, for example, splitting tongues  38 , which splitting tongues  38  are arranged to be movable in such a way that, depending on the position of the splitting tongues  38 , each incoming product  02  is guided into one or the other of the two alternative transport track  36 ,  37 . In this way, it is possible to, for example, alternatively guide respectively one product  02  into one or into the other transport track  36 ,  37  and to feed the product  02 , depending on which one of the two alternative transport tracks  36 ,  37  it is fed to, to transport it to two different downstream located processing stages  01 . Transporting of the products  02  on the tracks  33 ,  36 ,  37  can, in principle, take place in the most diverse manner by the use of transport systems, such as, for example, by belt or chain conveyors, or by the use of belt or belt systems which enclose the products  02  on both sides. The transport systems of the several tracks  33 ,  36 ,  37  can be driven by several drive mechanisms, which are independent of each other, or can be driven by a common drive mechanism.  
         [0062]     In conventional systems, clocking, timing or synchronization of the splitting device  34 , or of the splitting tongue  38 , with the product  02 , takes place mechanically by coupling it with a drive mechanism of a processing stage and/or of the transport system. The disadvantage of such a system resides in that products  02  which may have slipped, with respect to the transport system, or products  02  which were supplied too late or which were supplied too early to the transport system, pass the shunt  34  at the wrong moment. The result is that incorrect guidance, or even jamming of the shunt  34  and a stop of the product transport, can result.  
         [0063]     The system  32  represented in  FIG. 10  is constructed with an optical detection device which is usable to determine the position of the products, or a phase relation of the products. For this purpose, the system has a sensor  39  for use in detecting a position of the products, or a phase relation of the products. Sensor  39  may be, for example, an optical sensor  39  which is located preferably at a short distance upstream of the shunt  34 , such as, at a distance of, for example, at most five product lengths, and particularly advantageously at a distance of less than two product lengths before the shunt  34 . The sensor  39  can detect the entry of the product  02  into the field of view, the exit of the product  02  from the field of view and/or its transport speed, and can output an appropriate signal. The output signal from the sensor  39  is provided to a control device  41 , which control device  41 , in turn, controls a drive mechanism  42  of the shunt  34 . The control device  41  is configured to synchronize the phase relation of the shunt  34  by use of the signal, and in particular to synchronize the position or phase of the splitting tongue  38 , with the arrival of the product  02 .  
         [0064]     In a first variation of a discontinuously operated drive mechanism  42 , the shunt  34  is brought into the required position by the drive mechanism  42 , such as, for example, by respective signals. This means that a shunt placement, which is respectively caused by a signal, is provided in the sequence of the detected products. A number of the products  02 , which are possibly located on the path, or the conveying track  33 , between the shunt  34  and the distant sensor  39  must be taken into consideration if the distance between the two is more than one product length  02 .  
         [0065]     In an advantageous variation of the present invention, the drive mechanism  42 , which may be, for example, configured as a motor  42 , is operated continuously and drives the splitting tongue  38  by the use of a gear, such as, for example, a crank gear. The number of revolutions and/or the position of the motor  42  is set by the control device  41 , and is synchronized to the product flow in such a way that, when a product  02  enters the shunt  34 , the splitting tongue  38  is in the desired position. For example, this synchronization can take place by taking into consideration the distance between the sensor  39  and the shunt  34  and the product speed. The speed of travel of the product  02  can be detected, for example either by the use of the sensor  39 , or can be determined from information regarding the speed of the transport system on the conveying track  33 . If the phase relation and/or the phase velocity between the signal for detecting the product  02  and that of the splitting tongue  38  no longer agrees, a correction of the rotary position and/or number of revolutions of the drive mechanism  42 , by the use of the control device, takes place. The exact synchronization between the product entry into the shunt  34  and the shunt position is possible by this coordination.  
         [0066]     The above-described optical detection, in the approach area of the shunt  34 , along with the appropriate control of the shunt  34  is, in principle, advantageously usable in systems with alternative transport track  36 ,  37  for the products  02 . However, this applies, in particular, within the framework of a system  32  with alternative processing tracks  36 ,  37  for intermediate products  02 , and, in particular, for printed products  02 , whose overall or total product flow is split in accordance with fixed standards, or is guided into a definite processing track, and wherein the split product flows are intended to be conducted to different processing stages for further processing. Such different processing stages can basically be, for example, folding, gluing, labeling, stamping, stacking, binding and/or stapling devices. In conventional systems, the clocking, timing or synchronization of the specific processing stage, such as, for example, the synchronization of the folding blade  03  of a folding apparatus, with the product  02  takes place mechanically by the coupling of the specific processing stage with the drive mechanism of an upstream or a downstream arranged processing stage or with the transport system which is conveying the product  02 . Again, the disadvantage here is that products  02  which have slipped with respect to the transport system, or products  02  which were supplied too late or too early to the transport system, can block the processing stage, or can, at least lead to erroneous product processing, such as, for example, to the formation of a wrongly placed fold. Furthermore, increased wear of the transport system, such as, for example, the belt system, or of the processing stage itself can be the result of such lack of synchronization.  
         [0067]     The product processing system  32 , which is represented in  FIG. 10 , is configured with the optical detection of the product position taking place upstream of the processing stage. System  32  has two alternative processing tracks  36 ,  37 , each with a processing stage in the form of a longitudinal folding apparatus  01  having a processing tool which is embodied as a folding blade. The longitudinal folding apparatuses  01  can each be conventional longitudinal folding apparatuses, or advantageously can be longitudinal folding apparatuses  01  in accordance with one of the above-mentioned embodiments and which are provided with a disk  15 , or an endless belt  12 , and which have a tool  03  that is embodied as a folding blade  03 , and in particular, which is embodied as a mechanically independently driven folding blade  03 .  
         [0068]     The upper and/or the lower longitudinal folding apparatus  01 , as depicted in  FIG. 10 , and preferably both has a drive mechanism  05  for the respective folding blade  03 , which folding blade drive mechanism  05  is mechanically independent from the transport system, as well as a sensor  18  that is located upstream of the folding gap  0  and which sensor  18  is usable for selecting, or determining the position, or a passage time, of a product  02 , or in other words the product phase relation. The movement of the folding blade  03  can be synchronized to the product phase or location by the use of the control device  10 . The sensor  18  for each alternative transport track detects the time of the passage of a product  02 . The synchronization of the movement of the folding blade  03  or, in case of a deviation from a desired value, the folding time, is corrected by the control device  10 . If the longitudinal folding apparatus  01  additionally has a movable buffer  13 ,  14  in accordance with the embodiments described above, such a movable buffer  13 ,  14  can also be synchronized via the associated control unit  19 , as seen in FIGS.  1  to  3 . The drive mechanism control unit  10  for the folding blade motor  05  and the control unit  19  for the movable buffer drive motor  16  can here be structurally combined and, if desired, can be a part of a higher order control arrangement.  
         [0069]     A particularly advantageously embodied system  32 , in accordance with the present invention in which a product flow is split in accordance with fixed standards, and in which the split product flows are intended to be fed to different processing stages for further processing, and in particular are intended to be fed to longitudinal folding apparatuses  01 , are configured with an above mentioned optical detection device for use in detecting the product position upstream of the shunt  34 , as well as for detecting the product position upstream of, or in the entry area of the alternative processing stages  01 .  
         [0070]     The above-described longitudinal folding apparatuses  01  are preferably embodied as a so-called third fold. A first, longitudinal folding unit, such as, for example, a former, as well as a second, transverse folding apparatus, such as, for example, a folding jaw cylinder working together with a folding blade cylinder, are arranged upstream, or before, in a direction of product travel, the third fold forming apparatuses  01 .  
         [0071]     While preferred embodiments of a system comprising alternative processing sections for the further processing of products, longitudinal folding device and method for the synchronous operation of a folding device, in accordance with the present invention, are set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example the type of printing presses used, the types of upstream processing devices, and the like could be made without departing from the true spirit and scope of the present invention, which is accordingly to be limited only by the appended claims.