Abstract:
A device for manipulation of flat articles such as sheets of paper, plastic, cardboard and the like has at least one adjustable conveying unit with conveying elements, especially rollers. The at least one conveying unit is adjustable between at least two positions for performing at least two manipulations on the article. At least one switch that is adjustable between at least two positions for performing at least two manipulations on the article is provided.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns an apparatus for manipulating flat articles such as sheets of paper, plastic, cardboard and the like, comprising conveying elements, in particular rollers. 
     In the manipulation of printed sheets, for example, for folding, devices are used that are provided with folding pockets. With such folding pockets it is only possible to process a predetermined sheet size and a certain folding variant. While operating, only the set number of the products, i.e., the number of collected sheets e.g. for each mailing, can be varied. When the sheet size or the folding variant is to be changed, the machine must be stopped and newly adjusted or retrofitted so that undesirable downtimes result. Also, mixed variable products by so-called print on demand cannot be produced. 
     Such a folding apparatus is disclosed in EP 0 844 205 B1. 
     In order to enable a change of the folding variant during operation, it has already been attempted to install parallel systems in a machine which systems can be activated as needed; however, this requires a great expenditure and a large space. 
     Moreover, it has been attempted to supply pre-manufactured semi-finished products (for example, advertisement or other inserts) on a special transport stretch to the mailing to be produced which however requires also a great expenditure, a large space, and complex logistics for providing and supplying the correct product to the correct mailing. Producing mixed variable products by so-called print on demand is also not possible with these solutions. 
     The invention has therefore the object to provide a device as well as a machine provided therewith which the manufacture of selectively combined products, for example, mailings, is possible in a simple way with a great variety of variants. 
     SUMMARY OF THE INVENTION 
     The object is solved according to the invention in that the conveying elements are part of at least one adjustable conveying unit that, for performing at least two manipulations on the article, is adjustable between at least two positions. This object is further solved in accordance with the present invention in that the device has at least one switch that is adjustable between at least two positions for performing at least two manipulations on the article. 
     With the device according to the invention, it is possible to variably prepare and process the articles. Since the conveying elements can be adjusted between the different positions, the articles can be prepared and processed differently. For example, depending on the adjustment different folding types can be produced and/or the fold lengths can be changed. The conveying elements can also be adjusted such that the articles are transported without processing through the device. In this connection, the articles can also be diverted or the articles can be turned individually or combined two sets. In this connection, the device can be adjusted from article to article as needed so that sequentially supplied articles can be subjected to different processing steps. 
     With the adjustable switch it is also possible to process the article selectively. 
     Further features of the invention result from the additional claims, the description and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail with the aid of some embodiments illustrated in the drawings. It is shown in: 
         FIG. 1  in schematic illustration two sequentially arranged devices according to the invention embodied as folding devices through which the article is transported without being processed; 
         FIG. 2  the devices according to  FIG. 1  producing a V fold on the article; 
         FIG. 3  in an illustration corresponding to that of  FIG. 1  the manufacture of a Z fold on an article with the devices according to the present invention as shown in  FIG. 1 ; 
         FIG. 4  in an illustration corresponding to  FIG. 1  the two devices producing a C fold on the article; 
         FIG. 5  to  FIG. 9  in a schematic illustration five positions of the device according to the invention for producing a V fold; 
         FIG. 10  to  FIG. 12  three sequentially arranged devices according to the invention in schematic illustration; 
         FIG. 13  to  FIG. 15  in an illustration corresponding to  FIGS. 10 to 12  a further embodiment of a device according to the invention; 
         FIG. 16  in schematic illustration folding of a V fold with a device according to the invention; 
         FIG. 17  in an illustration according to  FIG. 16  three of the sequentially arranged devices according to the invention for producing a V fold; 
         FIG. 18  in an illustration corresponding to  FIG. 16  the three sequentially arranged devices according to the invention for producing a Z fold; 
         FIG. 19  in an illustration corresponding to  FIG. 16  the three devices according to the invention for producing a C fold; 
         FIG. 20  to  FIG. 24  in schematic illustration the production of a V fold with the device according to the invention; 
         FIG. 25  to  FIG. 28  in schematic illustration the adjustment of the device according to the invention for turning the article; 
         FIG. 29  to  FIG. 31  in schematic illustration a device according to the invention with the possibility to divert the article away from the article flow; 
         FIG. 32  to  FIG. 34  in schematic illustration a device according to the invention showing different adjustments; 
         FIG. 35  to  FIG. 40  different adjustments of the device according to the invention for processing the article; 
         FIG. 41  in a plan view and in schematic illustration a machine for further processing of articles with devices according to the invention; 
         FIG. 42  in schematic illustration a pressing module for processing the article; 
         FIG. 43  to  FIG. 48  a further embodiment of a device according to the invention with different adjustments; 
         FIG. 49  to  FIG. 52  a further embodiment of a device according to the invention in different adjustments; 
         FIG. 53  a side view of a machine for processing articles with devices according to the invention in schematic illustration; 
         FIG. 54  a plan view onto the device according to  FIG. 53 ; 
         FIG. 55  and  FIG. 56  in illustrations corresponding to  FIGS. 53 and 54  a further embodiment of a machine with devices according to the invention; 
         FIG. 57  to  FIG. 60  in a plan view and in schematic illustration, respectively, further embodiments of machines with devices according to the invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The invention will be explained in more detail in the following with the aid of preferred embodiments with reference to the attached drawings. 
     In  FIGS. 1 to 9  different applications of a folding device are illustrated. As can be seen in  FIG. 1 , two pocket-less folding devices F 1  and F 1 ′ according to the invention are sequentially arranged. In each of the folding devices there are two intake rollers, folding rollers, and auxiliary rollers each arranged axis-parallel to one another and rotatably supported and driven by servo motors. The intake rollers  1 ,  3 ;  1 ′,  3 ′ are supported directly on the frame (not illustrated) while the auxiliary rollers  5 ,  7 ;  5 ′, 7 ′ and the folding rollers  9 ,  11 ;  9 ′,  11 ′ are supported on a pivot frame that is also not illustrated which, in turn, is pivotably supported on the frame about pivot point D 1 . The auxiliary rollers  5 ,  7 ;  5 ′,  7 ′ have identical diameter that is however smaller than the diameter of the two folding rollers  9 ,  11 ;  9 ′,  11 ′. 
     The following function results: A sheet B is gripped by the intake rollers  1 ,  3  of the first folding device F 1  and supplied past the auxiliary rollers  5 ,  7  to the folding rollers  9 ,  11  and transported by them farther to the intake rollers  1 ′,  3 ′ of the second folding device F 1 ′. The sheet B also passes through the second folding device F 1 ′ without being folded and is transported farther by the transport rollers or intake rollers  13 ,  15  of a further module. This function illustrates that machines can be combined from modules that are arranged in series and illustrates that certain sheets can pass the machine without the folding function being employed. In this way, the desired production of printed sheet products by print on demand is made possible. 
     In  FIG. 2 , the pivot frame of the first folding device is pivoted about the pivot axis D 1  in the clockwise direction such that the sheet B, initially coming from the intake rollers  1 ,  3 , is guided outwardly through the auxiliary roller  8  and the folding roller  11  as well as the auxiliary roller  5  and the folding roller  9  until a length that is required for folding is reached. This required length is detected by sensor S 1  and, subsequently, the auxiliary and the folding rollers  5 ,  9  change their direction of rotation. While the auxiliary and folding rollers  7 ,  11  continue to push the sheet in unchanged direction, the leading part of the sheet is pushed by the auxiliary and folding rollers  5 ,  9  in the opposite direction so that in the sheet a bulge  85  is formed that reaches the nip between the folding rollers  9 ,  11  and is folded to the so-called V fold. The folded sheet passes through the second folding device F 1 ′ without further processing and is then transported farther by the rollers  13 ,  15  to the downstream module of the machine. 
     In  FIG. 3 , by means of the two folding devices F 1  and F 1 ′ a so-called Z fold is produced. First, in the folding device F 1 , as described above, at the leading third of the sheet a V fold is formed. The thus pre-folded sheet is then guided by the intake rollers  1 ′,  3 ′ of the second folding device F 1 ′, with the pivot frame being pivoted counterclockwise downwardly, between the auxiliary roller  5 ′ and the folding roller  9 ′ and farther between the auxiliary roller  7 ′ and the folding roller  11 ′. When the sensor S 2 ′ detects the correct position for folding of the pre-folded sheet, the rotational direction of the auxiliary roller  7 ′ and of the folding roller  11 ′ is reversed so that the sheet begins to bulge (bulge  86 ), is pulled into the nip between the folding rollers  9 ′,  11 ′, and is finished by forming the Z fold. The rollers  13  and  15  further convey the sheet folded in this way. The sheet B has thus two folds  85 ,  86 . 
     In  FIG. 4 , finally the formation of a so-called C fold in folding devices according to the invention is illustrated. In the folding device F 1  first, as already explained, a V fold  85  is formed that is provided at the end of the leading third of the sheet. The pre-folded sheet is then supplied to the second folding device F 1 ′ with the pivot frame being pivoted upwardly in the clockwise direction. The sheet passes through the nip between the auxiliary roller  7 ′ and the folding roller  11 ′ as well as the nip between the auxiliary roller  5 ′ and the folding roller  9 ′ until the sensor S 2 ′ detects the correct initial position of the sheet for creating the C fold and triggers reversal of the rotational direction of the auxiliary roller  5 ′ end of the folding roller  9 ′. In this way, again a bulge  86  of the sheet in the direction toward the nip between the folding rollers  9 ′ and  11 ′ is effected. The leading edge of the folded sheet is however not entrained as the bulge is produced and is thus not pulled into the nip between the two folding rollers  9 ′ and  11 ′. For this reason, in the frame of the folding device F 1 ′ a folding element  17  is provided that is linearly reciprocatingly movable (arrow  87 ) in the frame transverse to the folding nip between the folding rollers  9 ′,  11 ′ and upon reversal of movement direction of the rollers  5 ′ and  9 ′ is advanced briefly in the direction of the nip between the rollers  9 ′ and  11 ′ so as to guide the sheet edge into the nip. After passing through the rollers  9 ′ and  11 ′, the C fold is completed and the sheet can be further transported by means of the rollers  13 ,  15  to the next module of the machine. The folded sheet parts of a C fold rest immediately on one another. 
     For a better understanding, the manufacture of a V fold in a folding device according to the invention without pocket in accordance with claim  1  is illustrated in  FIGS. 5 to 9  in five intermediate positions: 
       FIG. 5  shows the incoming sheet B in the folding device F 1  with upwardly pivoted pivot frame so that the sheet B is first gripped by the rollers  7 ,  11  and transported farther in the direction toward the rollers  5 ,  9 . 
     In  FIG. 6  the sheet is already between the rollers  5 ,  9  and the sensor S 1  detects momentarily the leading edge  88  of the sheet B. 
       FIG. 7  shows the moment at which the sensor S 1  detects the required spacing relative to the leading edge  88  for forming the V fold and has just initiated reversal of the rotational direction of the rollers  5 ,  9 . A bulge  85  of the sheet B in the direction toward the nip between the folding rollers  9 ,  11  can be easily recognized. The pivot frame, in comparison to the position according to  FIG. 6 , has been partially returned counterclockwise. The auxiliary roller  7  is located at the level of the roller nip between the two intake rollers  1 ,  3 . 
     Finally, in  FIG. 8  the return pivot action of the pivot frame into the initial position according to  FIG. 1  at the moment of pulling the fold  85  between the folding rollers  9 ,  11  can be seen. The sheet B is in this way deflected downwardly so that the fold formation between the folding rollers  9 ,  11  is facilitated. Subsequently ( FIG. 9 ), the folded sheet is gripped by the rollers  13 ,  15  and transported farther to the next processing module. 
     In  FIGS. 10 to 12  a further embodiment of a folding device F 2  according to the invention is illustrated in which in a frame (not illustrated) the folding and auxiliary rollers are rotatably supported each in an upper and a lower pivotable frame (also not illustrated) about pivot point D 2 . The upper pivot frame supports two folding rollers  33 ,  34  and two auxiliary rollers  37 ,  38  and comprises two immobile first guiding elements L 1  and L 2  that secure in certain positions of the folding rollers the further transport of the sheets B between the auxiliary rollers  37 ,  38  of the upper pivot frame. The auxiliary rollers  37 ,  38  of same size have again a smaller diameter than the folding rollers  33 ,  34  of same size. The guiding elements L 1 , L 2  extend parallel to one another between the two auxiliary rollers  37 ,  38 . Their lower ends are outwardly bent in opposite directions relative to one another so that a funnel-shaped widened insertion opening for the sheets B is formed between folding rollers  33 ,  34 . 
     The lower pivot frame supports three folding rollers  30 ,  31 ,  32  and two auxiliary rollers  35 ,  36  and has two immobile second guiding elements L 3 , L 4  that also ensure, as a function of the position of the folding rollers relative to one another, further transport of the sheets B between the auxiliary rollers  35 ,  36  of the lower pivot frame. The auxiliary rollers  35 ,  36  of same size have a smaller diameter than the folding rollers  30  to  32  of same size. The guiding elements L 3 , L 4  extend also parallel to one another between the two auxiliary rollers  35 ,  36 . In the area between the folding rollers  30 ,  32  the ends of the guiding elements L 3 , L 4  for forming a funnel-shaped, widening insertion opening are curved outwardly in opposite directions to one another. 
     In  FIGS. 10 through 12  the sequential arrangement of three folding devices F 2  is illustrated. 
     In  FIG. 10 , the lower pivot frame with the folding rollers  30 ,  31 ,  32  is pivoted downwardly and a sheet B being fed between the folding rollers  33  and  34  of the upper pivot frame and the folding roller  31  of the lower pivot frame is passing through without being processed. 
     In  FIG. 11  the lower pivot frame has been pivoted about pivot axis D 2  toward the upper pivot frame so that the folding roller  31  interacts with the folding rollers  33  and  34  of the upper pivot frame. 
     The incoming sheet B reaches the nip between the folding rollers  33  and  31  and from there the area between the guiding elements L 1  and L 2 . They guide the sheet B between auxiliary rollers  37  and  38 . A sensor (not illustrated) detects the leading edge  88  of the sheet and reverses the auxiliary rollers  37  and  38  with respect to their rotational direction as soon as the folding length for the leading part of the sheet B is reached. By reversing the auxiliary rollers  37 ,  38  a bulge  85  of the sheet is formed in the direction toward the nip between the folding rollers  31  and  34  until the bulge  85  is pulled into the nip, the sheet is folded, and transported farther to the downstream folding device in which, according to  FIG. 12 , the lower pivot frame has been pivoted about the pivot axis D 2  even father upwardly and the upper pivot frame has been pivoted about the pivot axis D 2  also upwardly. The sheet B that has been pre-folded by the folding device according to  FIG. 11  and transported farther now reaches the area between the folding rollers  30  and  31  and is guided into the area between the immobile guiding elements L 3  and L 4 . They, in turn, guide the pre-folded sheet between the auxiliary rollers  35  and  36 . A sensor (not illustrated) detects again the leading edge  85  of the pre-folded sheet and reverses the rotational direction of the auxiliary rollers  35  and  36  as soon as the required sheet length for the further fold formation has been received between the auxiliary rollers  35  and  36 . The sheet B is bulged by reversal of the auxiliary rollers  35  and  36  in the direction toward the nip between the folding rollers  31  and  32  (bulge  86 ) and finally pulled into the nip, folded, and transported away or guided to the downstream processing module of the machine A. 
     The folding rollers  30  and  32  to  34  are advantageously spring-loaded in the direction of the sheet B so that the sheet B is transported without problems between the different rollers. All rollers  30  to  34 ,  37 ,  38  are positioned axis-parallel to one another. 
     In  FIGS. 13 to 15  a further embodiment of a folding device F 3  with its possible functions is illustrated. 
     The folding device F 3  according to the invention comprises a frame (not illustrated) as well as five folding and at least four auxiliary rollers that are all arranged axis-parallel to one another and are rotatably supported. Two of the folding rollers  40 ,  41  are rotatably supported together with two auxiliary rollers  42 ,  43  on a first push frame (in the embodiment the lower one). The three remaining folding rollers  44 ,  45 ,  46  are rotatably supported together with two auxiliary rollers  47 ,  48  on a second push frame (in the illustrated embodiments the upper one). The first and second push frames (also not illustrated) are supported in the frame so as to be linearly moveable relative to one another as well as with one another. On each push frame there are also immobile guiding elements attached that guide the sheet B from the folding rollers to the auxiliary rollers as well as back to the folding rollers. The folding rollers of each push frame have same diameter that is greater than the diameter of the auxiliary rollers of same size of each push frame. The folding rollers  40 ,  41 ,  44 ,  45  are advantageously spring-loaded in such a way that they transport the sheets B reliably through the folding device F 3 . 
     In  FIG. 13 , the two push frames that are slidably supported in the frame and support the folding and auxiliary rollers rotatably are spaced from one another in that the second (upper) push frame has been pushed upwardly and therefore the folding rollers  40 ,  41  of the first push frame no longer interact with the folding rollers  44 ,  45 ,  46  of the second push frame so that a sheet B of the folding device passes through without being processed and is conveyed to the downstream folding device according to  FIG. 14 . 
     In the folding device according to  FIG. 14  the second push frame has been moved downwardly toward the first push frame and the second and the first push frames together have been moved farther downwardly. The incoming sheet B thus reaches the area between the folding rollers  44  and  46  of the second push frame and is then guided between the immobile guiding elements L 7 , L 8  upwardly between the auxiliary rollers  47 ,  48 . A sensor (not illustrated) detects, as in the preceding embodiments, the leading edge  88  of the sheet and reverses the auxiliary rollers  47 ,  48  in their rotational direction as soon as the sheet length required for the first folding action has been received between the auxiliary rollers  47 ,  48 . By reversing the auxiliary rollers  47 ,  48  the sheet B bulges at the folding location in the direction toward the nip between the folding rollers  45 ,  46 , is pulled into the nip, folded (fold  85 ) and transported away or conveyed to the folding device according to  FIG. 15 . 
     In comparison to  FIG. 14 , in the folding device according to  FIG. 15  the two push frames have been pushed upwardly. In the folding device illustrated in  FIG. 15  the incoming pre-folded sheet B is gripped between the folding rollers  40  and  46  and is guided by the immobile guiding elements L 5 , L 6  of the first push frame between the auxiliary rollers  42 ,  43 . A sensor (not illustrated) detects again the incoming leading edge of the pre-folded sheet and reverses the rotational direction of the auxiliary rollers  42 ,  43  as soon as the required folding length of the sheet has been received. By reversing the rotational direction of the auxiliary rollers  42 ,  43  the sheet bulges in the direction toward the nip between the folding rollers  41  and  46  and is pulled in between the folding rollers  41  and  46 , folded (fold  86 ) and transported away or conveyed to the next module of the machine A. 
     The guiding elements L 5  to L 8  are identical and arranged in the same way as the guide elements L 1  to L 4  of the embodiment according to  FIGS. 10 to 12 . 
     In  FIGS. 16 to 19  the multitude of functional possibilities of a folding device F 4 , F 4 ′, and F 4 ″ according to the invention are illustrated. 
       FIG. 16  shows three folding devices F 4 ′ connected in series in which two intake rollers  50 ,  51 , four folding rollers  53 ,  54 ,  55 ,  56 , and two reversing rollers  57 ,  58  are arranged on a frame G axis-parallel to one another and are rotatably supported. On the frame G there are moreover immobile guiding elements L 10 , L 11  as well as movably supported guiding elements L 15 , L 16 . The intake roller  50  and the folding rollers  53 ,  55 ,  56  are spring-loaded in the direction of the sheet B being transported past them. The immobile guiding elements L 10 , L 11  are arranged horizontally sequentially behind one another and spaced from one another and are positioned at the level of the roller nip between the intake rollers  50 ,  51 . 
     The sheet B is fed between the intake rollers  50  and  51  and, because the movable guiding element L 15  has been pivoted upwardly out of the path of the sheet, is guided on the immobile guiding element L 10  toward the folding rollers  54 ,  55 , passes through the folding nip without being processed and is then conveyed by the guiding element L 11  to the intake rollers of the folding device F 4 ′ arranged downstream. The rollers of this as well as a further downstream folding device F 4 ″ are adjusted such that the sheet is transported through the machine without being manipulated or folded. Based on  FIG. 16  it is apparent that the folding devices combined in the machine as functional modules are indeed controllable on the fly, i.e., a sheet, as needed, can pass through the modules of the machine without being processed. 
       FIG. 17  shows the production of a V fold in the folding device F 4 . 
     After having passed the intake rollers  50 ,  51  the sheet B is guided by the movable guiding element L 15 , that has been pivoted into the movement path of the sheet B, into the nip of the folding rollers  53 ,  54  and is conveyed by the immobile guiding elements L 12 , L 13  between the reversing rollers  57 ,  58 . The guiding element L 15  has an arc-shaped curved end with which it extends into the roller nip between the intake rollers  50 ,  51 . This curved end is positioned at a minimal spacing opposite the guiding element L 10 . From the arc-shaped end the guiding element L 15  extends in this position at a slant upwardly to the folding nip between the folding rollers  53 ,  54 . In this way, the sheet B is reliably guided to the folding rollers  53 ,  54 . After passing through the folding nip, the sheet reaches the funnel-shaped widened insertion opening between the guiding elements L 12 , L 13  that guide the sheet B to the reversing rollers  57 ,  58 . A sensor S 4  is provided at the reversing rollers  57 ,  58  that detects the leading sheet edge  88  and reverses the reversing rollers  57 ,  58  as soon as the required sheet length for fold formation has passed the reversing rollers. After reversing the rotational direction of the reversing rollers  57 ,  58 , the sheet B bulges in the direction toward the folding nip of the folding rollers  54 ,  56  and is pulled into the folding nip and folded. The left folding device F 4  of  FIG. 17  shows the sheet upon entering the folding nip of the folding rollers  54 ,  56 . After the V fold  85  has been formed, the sheet B passes the two additional fording devices F 4 ′, F 4 ″ without further processing whose rollers are adjusted in accordance with  FIG. 16 . The guiding element L 16  is adjusted such that it extends from the intake rollers  50 ′,  51 ′ of the folding device F 4 ′ to the folding rollers  54 ,  56  of the folding device F 4 . The guiding element L 16  is of the same configuration as the guiding element L 15  and guides the folded sheet B reliably to the folding device F 4 ′. Its movable guiding elements L 15 ′, L 16 ′ are arranged outside of the movement path of the folded sheet. 
       FIG. 18  shows the formation of a Z fold. In the left folding device F 4  first, as explained above, a V fold  85  is formed and the sheet with the V fold  85  is further transported to the central folding device F 4 ′. In the central folding device F 4 ′ the arrangement of the rollers in the frame G, relative to the arrangement of the rollers in the left folding device F 4 , is displaced mirror-symmetrically downwardly relative to the horizontal central axis; this is indicated by means of the reference numerals marked with apostrophe. After the sheet B provided with the V fold  85  has passed the intake rollers  50 ′,  51 ′ of the folding device F 4 ′, the pre-folded sheet B is guided by means of the guiding element L 15 ′, that has been pivoted into the movement path, between the folding rollers  53 ′,  54 ′ and from here by means of the immobile guiding elements L 12 ′, L 13 ′ to the reversing rollers  57 ′,  58 ′. At the reversing rollers a sensor S 4 ′ is arranged that detects the folded sheet edge  85  and reverses the reversing rollers in their rotational direction as soon as the required sheet length for folding has passed the reversing rollers. By reversing the reversing rollers  57 ′,  58 ′, the sheet is caused to bulge in the direction toward the folding nip of the folding rollers  54 ′,  56 ′ and is pulled into the nip and folded (fold  86 ) as well as further transported by the movable guiding element L 16 ′ to the intake rollers  50 ,  51  of the folding device F 4 ″ to the right. The sheet B provided with the Z fold  85 ,  86  passes the right folding device F 4 ″ without being further processed because it is adjusted as shown in  FIG. 16 . 
     in  FIG. 19  the formation of a C fold by means of three folding devices F 4 ′ to F 4 ″ is illustrated. First, in the left folding device F 4 , as disclosed above, a V fold  85  is formed. The pre-folded sheet B is transported to the central folding device F 4 ′ that is adjusted in accordance with  FIG. 16  so that the pre-folded sheet B passes through the folding device F 4 ′ without being processed. After having entered between the intake rollers  50 ,  51  of the right folding device F 4 ″, the pre-folded sheet is guided by the guiding element L 15  that has been pivoted into the movement path to the folding nip of the folding rollers  53 ,  54  and is transported farther by them by means of the immobile guiding elements L 12 , L 13  between the reversing rollers  57 ,  58 . The sensor S 4  at the reversing rollers  57 ,  58  detects the folded edge  85  of the sheet B and reverses the rotational direction of the reversing rollers  57 ,  58  at the moment when the required sheet length for the next fold  86  has passed the reversing rollers  57 ,  58 . By reversing the reversing rollers the sheet is caused to bulge at the location  86  to be folded toward the folding nip of the folding rollers  54 ,  56 , is pulled into the folding nip, folded, and transported away or transferred to the next processing module of the machine. 
     In  FIGS. 20 to 24  the function of the reversing roller folding device F 4  according to the invention will be explained again step-by-step. 
     In  FIG. 20  the moment is illustrated at which the sheet B has passed the intake rollers  50 ,  51  and is guided by the guiding element L 15  that has been pivoted into the movement path to the folding nip of the folding rollers  53 ,  54  and supplied to the immobile guiding elements L 12 , L 13 . 
     In  FIG. 21  the sheet B is guided by the immobile guiding elements L 12 , L 13  to the reversing rollers  57 ,  58 . The sheet B has passed the reversing rollers  57 ,  58  to such an extent that the sensor S 4  has detected the leading edge  88  of the sheet. 
       FIG. 22  shows the sheet B shortly after reversing the rotational direction of the reversing rollers  57 ,  58 , i.e., the sheet has passed through the reversing rollers  57 ,  58  up to the length required for forming a fold. By reversing the reversing rollers  57 ,  58  the sheet is caused to bulge in a direction toward the folding nip of the folding rollers  54 ,  56 . 
     In  FIG. 23  the sheet B is just being pulled into the folding nip between the folding rollers  54 ,  56 . 
       FIG. 24  shows the sheet B that is provided with a V fold as it exits the folding rollers  54 ,  56 . The sheet B is transported away or is transported to a further processing module of the machine. 
     In  FIGS. 25 to 28  the turning of a sheet in a folding device F 4  according to the invention is illustrated. 
     In  FIG. 25  the position of the sheet B after gripping the sheet by the intake rollers  50 ,  51  and after further transport by the guiding element L 15  that has been pivoted into the movement path is shown. The sheet has already been gripped by the folding rollers  53 ,  54  and has been transported farther to the immobile guiding elements L 12 , L 13 . 
     In  FIG. 26  the sheet B has been transported farther by the immobile guiding elements L 12 , L 13  to the reversing rollers  57 ,  58 . The sensor S 4  arranged at the reversing rollers  57 ,  58  detects the leading edge  88  of the sheet B. 
     In  FIG. 27  the sheet B has passed the reversing rollers  57 ,  58  to such an extent that the sheet end  90  is free for being returned. This has been detected by the sensor S 4  that has triggered reversal of the rotational direction of the reversing rollers  57 ,  58 . 
       FIG. 28  shows the transport of the turned sheet B after having passed the folding rollers  54 ,  56 . The turned sheet B can be transported away or can be transported to a further processing module of the machine. 
     In  FIGS. 29 to 31  the use of a folding device F 4  according to the invention for diverting a sheet B out of the flow of sheets is illustrated. 
       FIG. 29  shows the sheet B entering between the intake rollers  50 ,  51  and the further transport by means of the guiding element L 15  that has been pivoted into the movement path to the folding rollers  53 ,  54  and farther to the immobile guiding elements L 12 , L 13  with which the sheet B is guided to the reversing rollers  57 ,  58 . 
     In  FIG. 30  the sheet B passes the reversing rollers  57 ,  58 . The sensor S 4  has detected the leading edge  88  of the sheet. Because the sheet, based on a command that can be provided by manual input, voice input or in any other way, is to be diverted, the sensor S 4  in this case will not reverse the rotational direction of reversing rollers  57 ,  58 . 
       FIG. 31  shows that the sheet B is guided by a further immobile guiding element L 20  that is arranged above the reversing rollers  57 ,  58  to a disposal  91 . The guiding element L 20  is curved and deflects the sheet B after having passed through the reversing rollers  57 ,  58  approximately at a right angle to the disposal  91 . The end of the guiding element L 20  that is facing the reversing rollers  57 ,  58  is positioned on an extension of the end of the guiding element L 12  facing the reversing rollers  57 ,  58 . In this way, the sheet  3  is reliably received by the guiding element  20 . 
       FIGS. 32 to 34  show a further folding device F 4 . It comprises two intake rollers  50 ,  51 , three folding rollers  71 ,  72 , and two reversing rollers  57 ,  58 . Moreover, this embodiment of the folding device has four immobile guiding elements L 18 , L 19 , L 20 , and L 21 , a removable guiding element L 22  as well as a sensor S 4 . The intake roller  50  and the folding rollers  70 ,  72  are spring-loaded in the direction of the sheet B passing through them. 
     First,  FIG. 32  will be explained. After the sheet B has entered the intake rollers  50 ,  51 , the sheet is guided by the immobile guiding element L 18  between the folding rollers  70 ,  71 . The guiding element L 18  is curved in such a way that it receives the sheet B after having passed the roller nip between the intake rollers  50 ,  51  and guides it to the folding nip between the folding rollers  70 ,  71 . After passing the folding rollers  70 ,  71  the leading edge  88  of the sheet is guided by the guide element L 22  that is movably supported on the frame G to the folding nip of the folding rollers  71 ,  72 . The guiding element L 22  is positioned in the area between the folding rollers  70 ,  72  and has a curved guiding surface  73  that is facing the guiding roller  71  and has approximately the same radius of curvature as said roller. The sheet B is guided across the guiding surface  73  to the folding nip between the folding rollers  71 ,  72 . The sheet B passes the folding nip between the folding rollers  71 ,  72  without being processed and is guided away by the immobile guiding element L 19  arranged on the frame G or supplied to a further processing module of the machine. The guiding element L 19  receives the sheet B as it exits from the roller nip between the folding rollers  71 ,  72 . 
     In  FIG. 33  the production of a V fold is illustrated. After having entered the intake rollers  50 ,  51 , the sheet B is received by the guiding element L 18  and transferred to the folding rollers  71 . The guiding element L 22  is adjusted such that its guiding surface  73  faces the folding roller  70  and a further curved guiding surface  74  that adjoins at an acute angle the guiding surface  73  supplies the sheet B to the immobile guiding elements L 20 , L 21  arranged on the frame G. The guiding surface  74  adjoins the lower end of the guiding element L 20  in  FIG. 33  so that the sheet B is guided safely between the two guiding elements L 20 , L 21  extending parallel to one another. By means of the latter, the sheet B is transported to the roller nip between the reversing rollers  57 ,  58  and is passed through it upwardly. The sensor S 4  detects the leading edge  88  of the sheet B and reverses the rotational direction of the reversing rollers  57 ,  58  as soon as the sheet length required for the fold has entered the reversing rollers. By reversing the rotational direction of the reversing rollers  57 ,  58 , the sheet B is caused to bulge at the folding location and pulled into the folding nip of the folding rollers  71 ,  72  and folded. After folding, the sheet B is transported away by the immobile guiding element L 19  or is supplied to a downstream processing module of the machine. 
     In  FIG. 34  the production of a Z fold in the folding device F 4  is illustrated. 
     A pre-folded sheet B provided with the fold  85 , for example, coming from the folding device according to  FIG. 33 , is inserted into the folding device F 4  according to  FIG. 34  and is supplied by the intake rollers  50 ,  51  through the immobile guiding element L 18  to the folding rollers  70 ,  71  and father to the reversing rollers  57 ,  58 . In contrast to  FIGS. 32 and 33 , the folding rollers  70  to  72  and the reversing rollers  57 ,  58  with the guiding elements L 18  to L 22  are arranged in a position rotated by 180 degrees. The guiding element L 22  is adjusted such that the guiding surface  73  is facing the folding roller  70  and the guiding surface  74  adjoins the now upper end of guiding element L 20 . Between the guiding elements L 20 , L 21  the sheet B is supplied to the roller nip between the reversing rollers  57 ,  58 . The sensor S 4  detects the folded leading edge  85  of the sheet and reverses the rotational direction of the reversing rollers  57 ,  58  as soon as the sheet length required for folding has been reached. By reversing the rotational direction of the reversing rollers  57 ,  58  the sheet is caused to bulge at the folding location in the direction toward the folding nip of the folding rollers  71 ,  72 . The folding rollers  71 ,  72  pull the bulging sheet edge in and form the fold  86 . The sheet B now provided with a Z fold is then guided away by the immobile guiding element L 19  arranged on the frame G or is supplied to a further processing module of the machine. 
     In  FIGS. 35 to 40  a further embodiment of a folding device F 4  is illustrated. 
       FIG. 35  shows that the sheet B after passing the intake rollers  50 ,  51  is supplied by means of the guiding element L 15  that has been pivoted into the movement path and is moveably supported on the frame G to the folding rollers  53 ,  54  and by means of the immobile guiding elements L 12 , L 13  arranged on the frame G to the reversing rollers  57 ,  58 . A sensor S 4  at the reversing rollers detects the leading edge  88  of the sheet and reverses the rotational direction of the reversing rollers  57 ,  58  as soon as the sheet length required for folding has been pulled in. By reversing the rotational direction of the reversing rollers  57 ,  58 , the sheet is caused to bulge in the direction toward the folding nip of the folding rollers  54 ,  56  and pulled between the folding rollers  54 ,  56  and folded (fold  85 ). 
       FIG. 36  shows how the sheet B after this pre-folding action is supplied by means of the movably supported guiding element L 16  to the folding roller pair  52 ,  59 . The guiding element L 16  receives the sheet B after having passed the folding nip between the folding rollers  54 ,  56  and supplies it to the folding nip between the folding rollers  52 ,  59 . A sensor S 4 ′ behind the folding rollers  52 ,  59  detects again the leading edge  85  of the folded sheet and reverses the rotational direction of the folding rollers  52 ,  59  as soon as the movably supported guiding element L 16  is free of the sheet B. Simultaneous with the reversal of the rotational direction of the folding rollers  52 ,  59  the movably supported guiding elements L 16 , L 15  are pivoted out of the movement path of the sheet so that the sheet B is moved horizontally between the folding rollers  54 ,  55  back to the intake rollers  50 ,  51  ( FIGS. 37 and 38 ). The sheet B, controlled by the sensor S 4 ″ in front of the intake rollers  50 ,  51 , is pulled back by the intake rollers  50 ,  51  until the movably supported guiding element L 15  can be pivoted again downwardly into the movement path of the sheet ( FIG. 39 ). Simultaneously with the lowering of the guiding element L 15  the rotational direction of the intake rollers  50 ,  51  is reversed and the pre-folded sheet B is supplied by means of the movably supported guiding element L 15 , the folding rollers  53 ,  54 , and the immobile guiding elements L 12 , L 13  back to the reversing rollers  57 ,  58  ( FIG. 40 ). The sensor S 4  detects again the leading edge  85  of the pre-folded sheet B and reverses the rotational direction of the reversing rollers as soon as the sheet length required for the second folding action has been pulled in by the reversing rollers  57 ,  58 . Reversal of the rotational direction of the reversing rollers  57 ,  58  leads to bulging of the sheet at the folding location of the new fold (fold  86 ) of the sheet illustrated in  FIG. 40 . The twice folded sheet B is then transported away by the lowered movably supported guiding element L 16  and the folding rollers  52 ,  59  out of the folding device or supplied to a further processing module of the machine. 
       FIG. 41  shows an embodiment of a machine A for further processing of printed sheets for producing printed sheet products, for example, mailings. 
     The machine is of a modular design and comprises an intake module  80 , an accumulator module  81 , a folding module  82  that is comprised of three folding devices according to the invention arranged sequentially behind one another, a buffering module  83  that is comprised of two buffers, as well as a collecting module  84 . All modules are arranged in series and are controllable on the fly. 
     The intake module  80  comprises in the illustrated embodiment a code reader  87  which decodes a code printed on the supplied sheets and that transmits the commands required for the function of the modules to the modules. The intake module comprises moreover a mechanism  92  for imbricating the sheets B. For supplying the sheets B, the mechanism  92  has slantedly positioned rollers that are rotatable about horizontal axes with which the sheets B are positioned on top another in an imbricate arrangement. 
     In the folding module  82  additionally an embossment module  93  according to  FIG. 42  can be arranged. When a larger number of sheets is to be folded, the fold locations can be pre-embossed by means of the embossment mechanism  93 . The embossment mechanism  93  has two roller pairs  94 ,  95  and  96 ,  97  that advantageously have the same diameter and are provided on the circumference with two embossment profiles  98 ,  99 . The embossment profile  98  has a tapering rib  100  projecting from the roller circumference. The embossment profile  99  has a matching recess  101 . The embossment profiles  98 ,  99  are positioned on the rollers  94  to  97  diametrically opposed to one another. For an embossment process the rollers of each roller pair are arranged relative to one another such that after each 180 degree rotation the rib  100  engages the recess  101  as is illustrated for the roller pair  94 ,  95 . The sheet that is passing through these rollers  94 ,  95  is embossed by the rib  100  in connection with the matching recess  101  at the required location. The folding process that follows in the folding device can be reliably performed as a result of the embossment. This embossment process is in particular advantageous when the folding action is carried out for a high set number and thus with relatively thick products. For example, it is recommended that beginning with sheet  5  or  6  of a sheet stack to emboss the folding edges on the individual sheet before collection in the accumulator module  81 . 
     When an embossment process is not to be performed, the rollers can be rotated into a passing position as illustrated in  FIG. 42  for the roller pair  96 ,  97 . The radius of the rollers outside of the embossment profiles  98 ,  99  is smaller than half the axis spacing of the rollers  96 ,  97 . In this way, the rollers in the passing position are spaced from one another. The embossment profiles  98 ,  99  are positioned displaced by 90 degrees relative to the embossment position. 
     When the rollers in the embossment position are in the position illustrated for the rollers  94 ,  95 , an embossment and later on folding in the upward direction is carried out because the rib  100  of the lower roller  95  is pointing upwardly and engages the downwardly open recess  101  of the upper roller  94 . When the two rollers  94 ,  95  are rotated by 180 degrees, the rib  100  of the upper roller  94  is oriented downwardly and engages the upwardly open recess  101  of the lower roller  95 . In this case, the embossment and the subsequent folding action are done in a downward direction. 
     In the gaps between the sequentially supplied sheets the rollers  94  to  97  are rotated into the required position, respectively. 
     Between the roller pairs  94 ,  95 ;  96 ,  97  there are conveying rollers  102 ,  103  with which the sheets are transported. 
     When no pre-embossment is required, the passing position of the embossment device to the right in  FIG. 42  can be adjusted on the fly. 
     By means of the machine A it is possible to produce a variety of different products that are transferred to the machine by print on demand. 
     The machine A is controlled based on (e.g. programmed) parameters that are predetermined for the individual (different) products to be produced, i.e., the individual modules are controlled and adjusted on the fly for processing each individual product. Each individual product can be produced individually in accordance with the parameters of the control, for example, by a data base or directly by the operator, for example, by display input or voice command. 
     Based on the  FIGS. 43 to 52  one embodiment will be explained in which the sheet B in the folding device F 4  is deflected such that without a separate turning process a different kind of fold can be produced. In the embodiment, a Z fold (zigzag fold) is produced. 
     The embodiment according to  FIGS. 43 to 52  corresponds substantially to the embodiment according to  FIGS. 35 to 40 . It has been described in this connection how by multiple passes in only one folding device F 4  a C fold (letter fold) can be produced. The folding device F 4  according to  FIGS. 43 to 51  differs from this embodiment in that instead of the movable baffle plate like guiding element L 16  a multi-guiding element MLE is provided. It is located in the area between the roller pairs  54 ,  55  and  52 ,  59 . The intake rollers  50 ,  51  again have the same diameter as the folding rollers  52 ,  56  and  59 . The multi-guiding element MLE has a substantially triangular base member with two curved guiding surfaces  104 ,  105  ( FIG. 49 ) that adjoin one another at an acute angle, wherein one of the guiding surface  104  has a smaller radius of curvature than the guiding surface  105 . At their ends that are facing away from one another the guiding surfaces  104 ,  105  are connected by a plane guiding surface  106  with one another that is positioned opposite a guiding element  107  that together with the guide surface  106  forms of passage  108  for the sheet B. 
     In the following, in an exemplary fashion the production of a Z fold will be described that can be produced without a separate turning step by means of the folding device F 4  according to  FIGS. 43 to 52 . 
     The sheet B is transported between the intake rollers  50 ,  51  and by means of the movable guiding element L 15  is supplied to the fold nip between the folding rollers  53 ,  54 . From here, the sheet B is transported by means of the guiding elements L 12 , L 13  to the reversing rollers  57 ,  58  between which it is transported in the described way. The sensor S 4  that is arranged in the transport direction of the sheet B behind the reversing rollers  57 ,  58  detects the leading edge  88  of the sheet B and triggers in the described way a switching signal by means of which the reversing rollers  57 ,  58  are reversed with respect to their rotational direction. The sheet B therefore is caused to bulge in such away that it reaches the folding nip between the two folding rollers  54 ,  56  so that the fold  85  is formed. 
     During formation of the first fold  85  the multi-guiding element MLE is adjusted such that the guiding surface  104  is positioned opposite the folding roller  54  at a minimal spacing. Since the guiding surface  104  has the same radius of curvature as the folding roller  54 , after the folding step the folded sheet B is transported between the multi-guiding element MLE and the folding roller  54 . The connecting edge  109  between the two guiding surfaces  104 ,  105  is positioned immediately adjacent the folding nip between the folding rollers  54 ,  56 . In this way it is ensured that the fold  85  moves between the multi-guiding element MLE and the folding roller  54 . The folded sheet B is thus applied to the folding nip between the folding rollers  54 ,  56  ( FIGS. 44 and 49 ). By a corresponding adjustment of the multi-guiding element MLE the sheet B is transported out of the folding area FB ( FIG. 49 ) to the intake area EB in front of the intake rollers  50 ,  51  with simultaneous turning. On the guiding element L 10  the single-folded sheet B is supplied to the intake rollers  50 ,  51  through which the sheet is transported partially. During this return transport of the sheet B the guiding element L 15  is pivoted upwardly so that it is no longer within the movement area of the sheet B ( FIG. 45 ). At least one sensor S 5  that in transport direction of the sheet B is located in front of the intake rollers  50 ,  51  detects the sheet B and stops the intake rollers  50 ,  51  at the moment when the sheet B with its trailing end is still barely within the roller nip between the intake rollers  50 ,  51  ( FIG. 46 ). Before reversal of the rotational direction of the intake rollers  50 ,  51  takes place, the guiding element L 15  is pivoted back into the movement path of the sheet B ( FIG. 46 ) so that the once-folded sheet B is again transferred by it to the folding nip between the folding rollers  53 ,  54 . After having passed the folding nip, the folded sheet B with its trailing end  90  moves between the guiding elements L 12 , L 13  that supply the sheet to the reversing rollers  57 ,  58  ( FIG. 47 ). 
     Advantageously, simultaneous to the return of the guiding element L 15  the multi-guiding element MLE is also adjusted about a horizontal axis such that the connecting edge  109  is resting on the wall of the folding roller  54  or at least has such a minimal spacing relative to it that the sheet B after passing through the folding nip between the folding rollers  54 ,  46  reaches the guiding surface  105  of the multi-guiding element MLE. 
     The sensor S 4  behind the reversing rollers  57 ,  58  grips the sheet end  90  and triggers a signal for reversing the rotational direction of the reversing rollers  57 ,  58 . Since the folding rollers  53 ,  54  are still being driven in the same rotational direction, the sheet B bulges in the folding area FB and enters the folding nip between the folding rollers  54 ,  56  ( FIG. 47 ). In this way, the second fold  86  is formed upon passing through the folding nip. The now twice-folded sheet B reaches the guiding surface  105  and is transported along it in the direction toward the folding nip between the two folding rollers  52 ,  59  ( FIGS. 48 and 51 ). Accordingly, the twice-folded sheet B is transported in the conveying direction from the folding area FB ( FIG. 51 ) to the exit area AB ( FIG. 51 ) behind the folding rollers  52 ,  59 . The sheet B provided with the Z fold  85 ,  86  is transported away or supplied to a following processing module of a machine. 
       FIG. 52  shows the case that this folding device F 4  can also be adjusted such that the sheet B passes through the folding device without being processed, i.e., without folding. In this case, the guiding element L 15  is pivoted upwardly out of the movement path of the sheet B. The multi-guiding element MLE is adjusted such that the connecting edge  109  rests against the folding roller  54  and has only minimal spacing. In this position, the passage  108  is positioned between the planar guiding surface  106  and guiding element  107  in the horizontal movement path of the sheet B. Since the guiding element L 15  has been pivoted out of the movement path of the sheet B, the sheet B is supplied by means of the intake rollers  50 ,  51  on the guiding element L 10  to the folding rollers  54 ,  56 . They convey the sheet through the downstream passage  108  to the folding rollers  52 ,  59 . After the sheet B has passed through the two folding rollers  52 ,  59 , the unprocessed sheet is transported away from the folding device F 4  or is supplied to a following module of a machine. 
     The multi-guiding element MLE can also be provided in place of the guiding element L 15 . It is also possible to employ the multi-guiding element MLE in the described position as well as additionally in place of the guiding element L 15 . 
     The use of the multi-guiding element MLE has the advantage that the sheet B in the folding device F 4  is deflected such that without a separate turning process a different kind of folding, for example, the described Z fold, can be produced. Depending on the adjustment of the folding device F 4 , the sheet B can also be provided with only one fold. In this case, the multi-guiding element MLE is adjusted in the way disclosed in  FIGS. 46 to 48 . By means of the sensor S 4  the rotational direction of the reversing rollers  57 ,  58  in this case is switched when a sufficient sheet length for the formation of only one fold has been transported between the reversing rollers  57 ,  58 . Then, by rotational reversal of the reversing rollers  57 ,  58  and the further drive action of the folding rollers  53 ,  54  that sheet B is caused to bulge into the folding nip between the folding rollers  54 ,  56  and in the folding nip the single fold is formed. The multi-guiding element MLE then guides in the position according to  FIGS. 46 to 48  the folded sheet to the downstream folding rollers  52 ,  59 . 
     In the described embodiment one of the intake rollers or the folding rollers is spring-loaded, respectively. This has the advantage that upon passing of the sheet through the roller nip or folding nip a pressure is applied onto the sheet. This is in particular advantageous when two or more sheets are conveyed at the same time through the folding device and folded. It is then possible to apply a satisfactory pressure on the fold. 
     The machine A that is illustrated in an exemplary fashion in  FIG. 41  comprises accumulator  81  with which the sheets B are combined to individual sets. In this connection, one set can be comprised of sheets of different lengths. However, it is also possible that the sheets B are individually sequentially supplied wherein in the accumulator  81  these individuals sheets are either laid on top one another or stacked from the bottom. Also, it is possible to combine individual sets of sheets in the accumulator  81 . In this case, it is for example possible to combine the first set of e.g. two sheets with a subsequent set of e.g. six sheets to a single set. Such accumulators are known and are therefore not disclosed in more detail. 
       FIGS. 53 and 54  show in an exemplary fashion a machine with which products are processed that are unwound from a roll  110  and are supplied by means of an intermediate module  111  to a cutting module  112 . By means of the cutting module  112  sheets B are cut from the endless web  113  and are supplied by corresponding transport elements  114  ( FIG. 54 ) to the accumulator  81 . The transport element  114  is, for example, a roller that is horizontal and positioned perpendicularly to the transport direction of the sheets and has a wall surface provided with passages  115 . The roller  114  is connected to a vacuum system with which by means of the passages  115  vacuum is applied to the sheets to be transported. The sheets are thus pulled tightly against the roller  114  that supplies the sheets reliably to the accumulator  81 . In the accumulator  81  the sheets are combined e.g. in imbricate arrangement ( FIG. 54 ) and then supplied to the folding module  82 . It is comprised of several folding devices, in the embodiment three sequentially arranged ones, with which the sheets or sheet sets are folded in the described way. Downstream of the folding module  82  there is a buffering module  83  with two sequentially arranged buffers. 
     In this variant the sheets are transported linearly through the different modules of the machine and are folded or transported without being folded, as needed. The folding devices of the folding module  82 , as has been explained in connection with the preceding embodiments in detail, can be adjusted as needed and independent from one another in such a way that the desired processing of the sheets is realized. It is possible to adjust all three folding devices in such a way that the sheets are transported without any processing to the buffering module  83 . However, all or only some folding devices of the folding module  82  can also be adjusted in the described way in order to achieve the desired folding of the sheets. 
     In the embodiment according to  FIGS. 55 and 56  the individual sheets are inserted into the machine and are subsequently processed. As in the preceding embodiment, the sheets are transported on a straight path through the machine. The device has a loading module  116  into which the individual sheets are inserted. By means of the transport element  114  the sheets are supplied to the accumulator module  81  in which the products to be processed are combined to sets. Downstream of the accumulator module  81  there is the folding module  82  that is comprised, for example, of three folding devices. In an exemplary fashion, they are of the same configuration as the folding devices according to  FIGS. 53 and 54 . The folding module  82  has downstream thereof a buffering module  83  that in accordance with the preceding embodiment is embodied for example with two sequentially arranged buffers. The folding devices in the folding module  82  are adjustable independent from one another so that the sheets, depending on the adjustment, can pass through the machine without being processed or can be provided with different folds. 
     The device according to  FIG. 57  has the intake module  80  in which a feeder with at least one transport element  114  re located. In the embodiment it is embodied identical to the transport element according to  FIG. 56 . With it, the sheets are supplied to the accumulator module  81  in which the sheets in the described way are combined to sets. A folding module  82  is arranged downstream of the accumulator module  81  and comprises, for example, three folding devices. As explained in connection with  FIGS. 53 to 56 , the folding devices can be adjusted independent from one another so that the sheets can be processed in different ways or are not processed. 
     A pressing module  117  is arranged downstream of the folding module  82  with which the sheets are pressed in the area of the fold. The pressing module  117  has two pressing rollers  121 ,  122 , that are forced against one another. In this way, the sheet is being pressed in the area of the fold. In this connection, it is even possible to move the sheet back and forth by appropriate reversal of the rotational direction of the pressing rollers  121 , 122  in order to exert a satisfactory pressure on the fold edge. 
     A buffering module  83  adjoins the pressing module  117  with which the processed or unprocessed sheets are guided away or supplied to another processing module of the machine. 
     The machine according to  FIG. 58  has the intake module  80  and the accumulator module  81  arranged downstream; they are of identical design as in the embodiment of  FIG. 57 . The folding module  82  downstream of the accumulator module  81  has three folding devices which, however, in contrast to the embodiment according to  FIGS. 53 to 57  are not arranged immediately behind one another but with intermediate positioning of a pressing module  117 , respectively. In this way, the fold provided in the folding device is immediately thereafter processed by means of the pressing module  117  before the sheet is supplied to the next folding device. Between the last folding device and the subsequent buffering module  83  a further pressing module  117  is arranged. 
     Since the machines according to  FIGS. 53 to 58  are designed such that the sheets are transported on a straight path through the machine,  FIG. 59  shows in an exemplary fashion a machine in which the transport direction of the sheets through the machine has two deflections. This machine comprises the intake module  80  with transport element  114  with which the sheets are supplied to the downstream folding module  82 . It has two folding devices and an adjoining pressing module  117 . The two pressing devices are adjustable independent from one another so that with them the sheets can be processed depending on the processing task. Depending on the adjustment of the respective folding device it is also possible that the sheets pass without being folded through the folding device. By means of the pressing module  117  the folds are processed. In the illustrated embodiment the pressing module has two pressing roller pairs with which the folds can be processed as the folded sheets pass between the pressing rollers. A corner conveying module  118  adjoins the pressing module  117  with which the transport direction of the sheets is changed by 90 degrees. After the 90 degree deflection the sheets reach a folding device  119  that has arranged downstream thereof a pressing module  117 . A further corner conveying module  118  adjoins the pressing module  117  with which the transport direction of the sheets is again deflected by 90 degrees. Downstream of the corner conveying module  116  there is a folding module  82  and a buffering module  83 . The folding module  82  has a folding device as well as a pressing module  117 . 
       FIG. 60  finally shows a machine in which the sheets are transported again without deflection through the device. The sheets are transported by means of the intake module  80  with the transport element  114  to the embossment module  120  that comprises embossment roller pairs  94  to  97  as disclosed in connection with  FIG. 42 . Downstream of the embossment module  120  there is the accumulator module  81  with which the sheets in the described way are combined to sets. 
     The folding module  82  adjoins the accumulator module  81  that in accordance with the machines of  FIGS. 53 to 56  has three sequentially arranged roller devices. In this connection, the folding device that adjoins the accumulator module  81  is provided with a diverting compartment. Downstream of the folding module  82  there is a pressing module  117  that has two pressing roller pairs. A buffering module  83  adjoins the pressing module  117  with which the sheets are diverted or supplied to a further module. 
     The examples of machines disclosed in connection with  FIGS. 53 to 60  show that based on the different modules each machine can be optimally combined in accordance with the wishes of the client in order to process the sheets with the modules. With the described folding devices with adjustable rollers and/or sheet guiding elements, different manipulations on the sheets can be carried out in the described way. The folding devices can be controlled flexibly so that each leaf or each sheet B can be folded in different ways. In this way it is achieved that for the same or variable initial sizes of the sheets signatures with different folding types can be folded to one or several defined final formats. It is possible without problem to adjust the folding rollers and/or the different guiding elements for each sheet so that sequentially supplied sheets can be folded in a variety of different ways. The adjustment of the folding rollers and of the guiding elements is possible within a very short period of time. Accordingly, the sheets can be processed individually. It is conceivable easily that each sheet or only the first sheet and/or the last sheet of each set of sheets can be provided with a barcode, for example, that is detected by a reading device that, according to the information contained in the barcode, will adjust the machine or the folding device in order to perform on the sheet the required processing steps. The sheets B can be supplied by a flat stacking feeder, a vacuum feeder, a cutting unit or a printer into the machine. In the latter case, the sheet is printed in the printer and subsequently immediately supplied to the folding device for processing. 
     The information in regard to preparing or processing each product (individual sheet or combined set) accompanies this product through the entire machine and can generate on the fly at any station of the machine appropriate adjustments or switching actions. This information can advantageously be provided in the form of a barcode on the product. The individual stations of the machine are provided with corresponding reading units that read the barcodes and accordingly adjust the stations. As has been described in an exemplary fashion, all kinds of folds can be produced. The folding lengths can vary. Depending on the position of the folding rollers and/or the guiding elements switching between folding and not folding can be realized. The sheets or sets of sheets can be controlled. In the machine individual sheets or even sets comprised of at least two sheets can be turned without problem. All these functions can vary from product to product because the information in regard to preparing and processing is present on each product and can be read from the product at any time upon passage through the machine.